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Necrotizing enterocolitis (NEC) is an intestinal inflammatory and necrotic disease seen in premature infants, and remains the leading cause of death resulted from gastrointestinal diseases in premature infants. The specific pathogenesis of NEC is still unclear. In recent years, a lot of studies have reported that Toll-like receptor 4 (TLR4) plays a key role in the pathogenesis of NEC. TLR4, which is abundantly expressed in intestinal epithelial cells of premature infants, binds to bacterial lipopolysaccharide (LPS) to activate downstream signaling pathways, leading to disruption of intestinal epithelial integrity and bacterial translocation, resulting in intestinal ischemic necrosis and inflammatory responses, which may rapidly progress to severe sepsis, multiple organ dysfunction, and death. This paper reviews the mechanism of TLR4-related signaling pathways in intestinal epithelial injury and inflammatory responses in newborns with NEC, providing a reference to study new therapeutic targets for NEC.

Objectives: To investigate the effects of asperosaponin VI (AVI) on intestinal epithelial cell apoptosis and intestinal barrier function in a mouse model of Crohn's disease (CD)-like colitis and explore its mechanisms., Methods: Male C57BL/6 mice with TNBS-induced CD-like colitis were treated with saline or AVI (daily dose 150 mg/kg) by gavage for 6 days. The changes in body weight, colon length, DAI scores, and colon pathologies of the mice were observed, and the expressions of inflammatory factors and tight injunction proteins were detected using ELISA and RT-qPCR. The effects of AVI on barrier function and apoptosis of mouse intestinal epithelial cells and TNF‑α‑treated Caco-2 cells were analyzed using immunofluorescence staining, TUNEL assay, and Western blotting. Network pharmacology, TUNEL assay, and Western blotting were performed to explore and validate the therapeutic mechanisms of AVI for CD., Results: In the mouse models of CD-like colitis, AVI significantly improved body weight loss, colon shortening and DAI and tissue inflammation scores, alleviated intestinal villi and goblet cell injuries, and lowered the expressions of inflammatory factors. AVI treatment significantly reduced the loss of tight junction proteins and apoptosis in both mouse intestinal epithelial cells and TNF‑α-stimulated Caco-2 cells. KEGG enrichment pathway analysis suggested that the therapeutic effect of AVI on CD was associated with inhibition of PI3K/AKT/NF-κB pathway activation, which was confirmed by lowered expressions of p-PI3K, p-AKT, and p-p65 in AVI-treated mouse models and Caco-2 cells. In Caco-2 cells, Recilisib significantly blocked the inhibitory effect of AVI on the PI3K/AKT/NF-κB pathway and TNF-α-induced apoptosis, and AKT1 knockdown experiment confirmed the role of the PI3K/AKT pathway for mediating the activation of downstream NF-κB signaling., Conclusions: AVI can improve TNBS-induced CD-like colitis in mice by reducing intestinal epithelial cell apoptosis and intestinal barrier damage via inhibiting the PI3K/AKT/NF-κB signaling pathway.

Objective: To explore the therapeutic efficacies of three different doses of human umbilical cord mesenchymal stem cell exosomes (hucMSC-EXO) on the injury of intestinal barrier structure and dysfunction in severely burned rats, and to identify the optimal dose of hucMSC-EXO for the repair of intestinal barrier injury. Methods: The hucMSC-EXO was isolated and identified by using an exosome extraction and purification kit. A total of 30 specific pathogen free (SPF) male Wistar rats (aged 6-8 weeks) were selected, and were randomly divided into five groups ( n =6) using a random number table: sham group, burn group, burn+100 μg hucMSC-EXO group (Burn+EXO100), burn+200 μg hucMSC-EXO group (Burn+EXO200), and burn+400 μg hucMSC-EXO group (Burn+EXO400). The rats were immersed in 94 ℃ water, with the dorsal area exposed for 12 seconds and the ventral area for 6 seconds, to establish a 50% total body surface area (TBSA) third-degree burn model. The sham group rats were subjected under the same condition but with a 37 ℃ water bath. On day 1, 3, and 5 post-burn, the rats in sham group and burn group received an intraperitoneal injection of 0.5 ml phosphate buffered solution, and those in Burn+EXO100, Burn+EXO200, and Burn+EXO400 groups received intraperitoneal injections of 100, 200, and 400 μg/0.5 ml hucMSC-EXO, respectively. The activity of rats was observed and the weight was recorded daily. On day 7, the small intestine tissues and serum of the rats were collected. Hematoxylin-Eosin (HE) staining was used to observe the pathological changes of the small intestinal tissues, and the levels of inflammatory factors, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8, IL-10 and lipopolysaccharide (LPS) of small intestine tissues were detected by enzyme-linked immunosorbent assay (ELISA). The levels of diamine oxidase, D-lactic acid and bacterial endotoxin in serum were detected by intestinal barrier function biochemical analysis system. Results: The morphology of hucMSC-EXO was observed to be round or oval, with uniform size and a peak diameter of approximately 100 nm, expressing positive markers CD63 and TSG101. In the sham injury group, the rats' body weight increased by approximately (6.3±1.2) g/day, whereas in the burn group, the body weight significantly decreased on the first day post-injury and then gradually increased at a rate of (1.6±0.5) g daily. In contrast, the body weight of the Burn+EXO100, 200, and 400 groups increased at a rate of (2.9±1.1) g daily. By day 7 post-injury, the body weight in the Burn+EXO200 and Burn+EXO400 groups were significantly higher than those in the burn group and the Burn+EXO100 group (all P <0.05). HE staining showed that the villus height in the small intestine (duodenum, jejunum, ileum) of the burn group [(711±35), (526±25), (418±33) μm] was significantly reduced with severe structural damage, while the small intestine structure and villus height in the EXO-treated groups showed varying degrees of recovery. The villus height in the Burn+EXO200 group [(1 050±40), (798±30), (609±29)μm, respectively] and burn+EXO400 group [(1 102±46), (830±28), (625±33)μm, respectively] recovered significantly (all P <0.05). ELISA results indicated that the levels of pro-inflammatory cytokines TNF-α, IL-1β, IL-6, IL-8, and LPS in the burn group [(29.3±1.7), (81.2±2.5), (582.4±36.9), (22.1±0.6), (366.8±15.9)ng/L, respectively] were elevated, while those were significantly reduced in the EXO-treated groups, with Burn+EXO200 group [(17.9±1.0), (58.2±2.3), (206.6±38.7), (8.9±1.0), (94.9±7.3)ng/L, respectively] showing the most significant reduction (all P <0.05). The level of anti-inflammatory cytokine IL-10 was elevated in the burn group [(293.4±16.0) ng/L], and it was significantly increased in the burn+EXO100, 200, and 400 groups [(591.8±40.7), (672.5±53.7), (712.5±36.2)ng/L, respectively] (all P <0.05). Assessment of intestinal barrier function showed that serum diamine oxidase in the burn group decreased, while D-lactate and bacterial endotoxin increased. The EXO-treated groups demonstrated significant improvement in diamine oxidase, D-lactate, and bacterial endotoxin levels, with Burn+EXO200 group showing the most significant effect (all P <0.05). Conclusions: In this study, hucMSC-EXO was successfully isolated, extracted, and identified. An intraperitoneal injection of 200 μg of hucMSC-EXO demonstrates the most effective repair of intestinal structure and function in rats with severe burn injuries.

To explore the mechanism by which vinegar-processed Euphorbiae Pekinensis Radix regulates gut microbiota and reduces intestinal toxicity, this study aimed to identify key microbial communities related to vinegar-induced detoxification and verify their functions. Using a derivatization method, the study measured the content of short-chain fatty acids(SCFAs) in feces before and after vinegar-processing of Euphorbiae Pekinensis Radix. Combined with the results of previous gut microbiota sequencing, correlation analysis was used to identify key microbial communities related to SCFAs content. Through single-bacterium transplantation experiments, the role of key microbial communities in regulating SCFAs metabolism and alleviating the intestinal toxicity of Euphorbiae Pekinensis Radix was clarified. Fecal extracts were then added to a co-culture system of Caco-2 and RAW264.7 cells, and toxicity differences were evaluated using intestinal tight junction proteins and inflammatory factors as indicators. Additionally, the application of a SCFAs receptor blocker helped confirm the role of SCFAs in reducing intestinal toxicity during vinegar-processing of Euphorbiae Pekinensis Radix. The results of this study indicated that vinegar-processing of Euphorbiae Pekinensis Radix improved the decline in SCFAs content caused by the raw material. Correlation analysis revealed that Bifidobacterium was positively correlated with the levels of acetic acid, propionic acid, isobutyric acid, n-butyric acid, isovaleric acid, and n-valeric acid. RESULTS:: from single-bacterium transplantation experiments demonstrated that Bifidobacterium could mitigate the reduction in SCFAs content induced by raw Euphorbiae Pekinensis Radix, enhance the expression of tight junction proteins, and reduce intestinal inflammation. Similarly, cell experiment results confirmed that fecal extracts from Bifidobacterium-transplanted mice alleviated inflammation and increased the expression of tight junction proteins in intestinal epithelial cells. The use of the free fatty acid receptor-2 inhibitor GLPG0974 verified that this improvement effect was related to the SCFAs pathway. This study demonstrates that Bifidobacterium is the key microbial community responsible for reducing intestinal toxicity in vinegar-processed Euphorbiae Pekinensis Radix. Vinegar-processing increases the abundance of Bifidobacterium, elevates the intestinal SCFAs content, inhibits intestinal inflammation, and enhances the expression of tight junction proteins, thereby improving the intestinal toxicity of Euphorbiae Pekinensis Radix.

Objective: To evaluate the therapeutic effect of Huangqin Decoction (HQD) on ulcerative colitis (UC) in mice and explore its mechanism., Methods: Male Balb/c mice were randomly divided into normal control group, model group, mesalazine group (5-ASA, 200 mg/kg), and low-, medium-and high-dose HQD groups (2.275, 4.55 and 9.1 g/kg, respectively). With the exception of those in the normal control group, all the mice were exposed to 3% DSS solution in drinking water for 7 days to establish UC models. After treatment with the indicated drugs, the mice were assessed for colon injury and apoptosis using HE, AB-PAS and TUNEL staining, and the expression levels of inflammatory factors were detected with ELISA. Western blotting, immunohistochemistry and qRT-PCR were used to detect the changes in protein expressions associated with the intestinal chemical barrier, mechanical barrier and endoplasmic reticulum stress (ERS)., Results: HQD treatment significantly reduced DAI score and macro score of UC mice, decreased colonic epithelial cell apoptosis, lowered expressions of IL-6, TNF-α, IL-1β and IL-8, and enhanced the expressions of MUC2 and TFF3. HQD treatment also upregulated the protein expressions of claudin-1, occludin and E-cadherin, reduced the expressions of GRP78, CHOP, caspase-12 and caspase-3, decreased the phosphorylation levels of PERK, eIF2α and IRE1α, and increased the Bcl-2/Bax ratio in the colon tissues of UC mice., Conclusion: HQD inhibits colonic epithelial cell apoptosis and improves intestinal barrier function in UC mice possibly by reducing ERS mediated by the PERK and IRE1α signaling pathways.

The study is designed to observe the mechanism of Tongfu Xiefei Guanchang Solution(TFXF) in the treatment of acute lung injury(ALI) in rats by improving intestinal barrier and intestinal flora structure via p38 mitogen-activated protein kinase(p38 MAPK)/myosin light chain kinase(MLCK) signaling pathway. Sixty SPF-grade Wistar rats were randomly divided into the control(CON) group, lipopolysaccharide(LPS) group(7.5 mg·kg~(-1)), LPS + dexamethasone(DEX) group(3.5 mg·kg~(-1)), LPS + high-dose(HD)-TFXF group(14.74 g·kg~(-1)), LPS + middle-dose(MD)-TFXF group(7.37 g·kg~(-1)), and LPS + low-dose(LD)-TFXF group(3.69 g·kg~(-1)). ALI model of the rat was established by intraperitoneal injection of LPS. The lactate dehydrogenase(LDH) activity and total protein concentration in the bronchoalveolar lavage fluid(BALF) were measured; tumor necrosis factor-α(TNF-α) and interleukin-1β(IL-1β) levels in lung and colon tissue of rats were detected by enzyme linked immunosorbent assay(ELISA). Hematoxylin-eosin(HE) staining was used to observe the pathological expression in the lung and colon tissue of rats. The mRNA expression of p38 MAPK, TNF-α, and IL-1β in rat lung tissue was determined by real-time fluorescence quantitative polymerase chain reaction(real-time PCR). Western blot was used to detect the protein expression related to the p38 MAPK/MLCK signaling pathway in the colon tissue of rats. 16S rRNA sequencing was used to detect changes in the composition and content of intestinal flora in rats, and correlation analyses were performed to explore the regulatory role of intestinal flora in improving ALI in rats. The results showed that compared with those in the LPS group, the histopathological scores of lung and colon tissue, LDH activity, and total protein concentration in BALF were significantly reduced in rats in all groups after drug administration. Except for the LPS + LD-TFXF group, the remaining groups significantly reduced the levels of TNF-α and IL-1β in the lung and colon tissue of rats. The protein expressions of phosphorylated p38 mitogen-activated protein kinase(p-p38 MAPK)/p38, phosphorylated myosin light chain(p-MLC)/myosin light chain 2(MLC2), and MLCK in colon tissue of rats in each drug administration group were significantly decreased. The mRNA expression levels of p38 MAPK, TNF-α, and IL-1β were significantly reduced in the LPS + HD-TFXF group. 16S rRNA sequencing results showed that the abundance of intestinal flora was significantly higher in the LPS + HD-TFXF group, and intestinal floras including Sobs, Shannon, and Npshannon were significantly higher. The β-diversity distribution of intestinal flora tends toward the CON group, and the abundance of Firmicutes was significantly higher. The abundance of Proteobacteria was significantly reduced; the abundance of Bacteroides was significantly reduced, and the abundance of Ruminococcus was significantly higher. The main species differences were Blautia, Roseburia＿sp＿499, and Butyricicoccus. TNF-α and IL-1β of lung tissue were negatively correlated with Muribaculaceae, unclassified norank＿f＿Eubacterium＿coprostanoligenes, and Ruminococcus and positively correlated with Bacteroides. Meanwhile, TNF-α and IL-1β of colon tissue were negatively correlated with unclassified norank＿f＿Eubacterium＿coprostanoligenes and Ruminococcus and positively correlated with Bacteroides. The predicted biological function of the flora was related to the biosynthesis of secondary metabolites, amino acid biosynthesis, sugar metabolism, and oxidative phosphorylation. The above studies show that TFXF can repair lung and colon tissue structure and regulate inflammatory factor levels by modulating the abundance and diversity of intestinal flora species in ALI rats. Its mechanism of action in ameliorating ALI in rats may be related to the inhibition of inflammation, improvement of intestinal mucosal permeability, and maintenance of intestinal flora homeostasis and barrier through the p38 MAPK/MLCK signaling pathway.

Bariatric surgery may cause intestinal microecological environment imbalance due to changes in gastrointestinal anatomy. Some patients may have compli-cations, even regain weight. Probiotics can act on intestinal mucosa, epithelium and gut-associated lymphoid tissue to improve the intestinal microecological environment of obese patients after bariatric surgery. Probiotics can promote the production of short-chain fatty acids, stimulate intestinal cells to release glucagon-like peptide-1, peptide tyrosine-tyrosine, insulin and other endocrine hormones, affect the function of the central nervous system through the gut-brain axis, make patients after bariatric surgery feel full, and reduce blood sugar at the same time. Probiotics can produce lactic acid, acetic acid and lactase, to inhibit the growth of harmful bacteria and to improve gastrointestinal symptoms of patients after bariatric surgery. Probiotics can activate the AMP-activated protein kinase signaling pathway, improve lipid metabolism, and promote the recovery of symptom indicators of nonalcoholic fatty liver disease after bariatric surgery. Probiotics can regulate the release of neurotransmitters or metabolites by the microbiota through the gut-brain axis to affect brain activity and behavior, thus helping patients improve negative emotions after bariatric surgery. This article describes the intestinal microecological environment of obese patients and mechanism of the change after bariatric surgery and summarizes the effects and possible mechanisms of probiotics in improving the intestinal microecological environment of obese patients after bariatric surgery, to provide references for promoting the clinical application of probiotics.

This study aims to elucidate the mechanism of Huangqin Decoction(HQD) in treating ulcerative colitis(UC) by investigating the relationship between tryptophan metabolism and intestinal barriers. In the in vivo experiments, 3% dextran sulfate sodium(DSS) was used to induce a mouse model of acute colitis, with mesalazine as a positive control. The therapeutic effect of HQD on mice with UC was evaluated according to body weight, disease activity index(DAI), colon length, and pathological changes. Targeted metabolomics was used to detect the concentration of tryptophan and its metabolites in mouse feces. Western blot and RT-qPCR techniques were used to assess the expression levels of colonic aryl hydrocarbon receptor(AhR), myosin light chain kinase(MLCK), myo-sin light chain(MLC), and p-MLC. Serum FITC-dextran concentration, bacterial culture of mesenteric lymph nodes and spleen, as well as fluorescence probe in situ hybridization technique were used to evaluate intestinal epithelial permeability. Alcian blue and nuclear fast red staining, Western blot, and RT-qPCR techniques were used to detect the expression of mucin secreted by the mouse's intestinal epithelial goblet cells. Transmission electron microscopy was utilized to observe the connections of the mouse's intestinal epithelial cells. Immunofluorescence, Western blot, and RT-qPCR techniques were used to assess the expression of tight junction proteins in the mouse's intestinal epithelium. In the in vitro experiments, lipopolysaccharide(LPS) was used to induce intestinal epithelial barrier injury model in Caco2 cells, and AhR siRNA was used to further clarify the mechanism of HQD in activating AhR to improve intestinal barrier function. The results demonstrated that HQD effectively alleviated symptoms and pathological changes in the colon of DSS-induced mice with colitis. Treatment with HQD could regulate tryptophan metabolism in the feces of mice with colitis, activate AhR, and improve the intestinal epithelial barrier. Additionally, the results of the in vitro experiments confirmed that HQD could restore the expression of tight junction proteins in the intestinal epithelium of colitis cells by activating AhR to regulate the MLCK/p-MLC signaling pathway.

Objective: To investigate the changes in gene expression related to intestinal fatty acid oxidation and carnitine metabolism in patients with ulcerative colitis (UC). Methods: A retrospective study was conducted involving patients with UC (UC group) and non-UC controls (control group) who underwent routine colonoscopy to exclude polyps at Peking Union Medical College Hospital between January 1, 2018, to December 31, 2023. Colon tissue samples were collected from both groups and RNA was extracted. Real-time fluorescence quantitative polymerase chain reaction technology was used to detect the mRNA expression levels of genes related to fatty acid oxidation and carnitine metabolism and to analyze their correlation with inflammatory gene expression. The expression of genes linked to fatty acid oxidation and carnitine metabolism was analyzed by analyzing the colonic mucosal transcriptome data of UC patients and controls in high-throughput gene expression database (GEO). Immunohistochemistry was used to examine the expression of the carnitine transporter SLC6A14 in the intestinal tissues of both groups at the protein level. Eight-week-old male C57BL/6 mice were selected and divided into a drinking water group (drinkind daily water) and a dextran sodium sulfate (DSS) group (drinking 2.5% DSS solution) with 4 mice in each group. DSS was used to induce an acute colitis model in mice and detect the difference in mRNA expression levels of SLC6A14 and interleukin-6 (IL-6) in the intestinal tissues of the both groups of mice. Results: A total of 22 patients were included in the UC group, with 12 males and 10 females, aged 16-64 (40±12) years. The control group consisted of 10 patients, with 3 males and 7 females, aged 43-72 (64±8) years. The UC group had lower mRNA expression levels of genes related to fatty acid oxidation and transport in the intestine compared to those in the control group, such as CD36 [0.40 (0.27, 0.55) vs 0.93 (0.39, 2.93)], CPT1A [0.39 (0.07, 0.54) vs 0.93 (0.41, 1.71)], CPT1B (0.37±0.36 vs 1.37±0.89), CPT2 [0.36 (0.30, 0.43) vs 1.14 (0.68, 1.34)], CRAT [0.31 (0.25, 0.41) vs 1.06 (0.64, 1.73)], CROT [0.14 (0.10, 0.21) vs 0.95 (0.77, 1.27)] (all P <0.05). The mRNA expression levels of genes related to carnitine transport in the UC group were lower than those in the control group, such as OCTN1 [0.18 (0.10, 0.41) vs 0.83 (0.41, 1.47)], OCTN2 [0.01 (0.00, 0.01) vs 0.47 (0.35, 2.15)] (both P <0.05). The mRNA expression levels of the carnitine transporter gene SLC6A14 in the intestine of UC patients was higher than that of the control group [11.31 (5.34, 23.50) vs 0.78 (0.07, 3.70), P <0.001], and showed a positive correlation with the inflammatory gene IL-6 ( r =0.425, 95% CI : 0.076-0.681, P =0.019). Analysis of the GEO database revealed lower expression levels of CD36, CPT1A, CPT2, CRAT and CROT in UC group compared to controls (all P <0.05), while the expression levels of SLC6A14 were higher than those in control group ( P <0.05). The protein expression level of SLC6A14 in colon tissue of UC group was higher than that of control group (0.45±0.07 vs 0.30±0.01, P =0.019). The mRNA expression of SLC6A14 in the intestine of DSS group was higher compared to that in the drinking water group (1.83±0.90 vs 0.60±0.10, P =0.035). Conclusion: The expression levels of genes associated with intestinal fatty acid oxidation and carnitine metabolism (CD36, CPT1A, CPT1B, CPT2, CRAT, CROT, OCTN1, and OCTN2) are decreased in UC patients, while the expression level of SLC6A14, a gene capable of transporting both amino acids and carnitine, is increased.

Objective: To investigate the effect and potential mechanisms of α-cyperone (CYP) on Crohn's disease (CD) -like colitis induced by 2, 4, 6-trinitrobenzene sulfonic acid (TNBS) in mice., Methods: The mice were randomly and evenly divided into wild type (WT), TNBS, CYP and 5-aminosalicylic acid (5-ASA) groups, with 10 mice in each group. The symptoms of enteritis, the function and structure of the intestinal barrier, and the expression levels of inflammatory factors, including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and gamma-interferon (IFN-γ), in the colon were assessed. The lipopolysaccharide (LPS)-induced inflammation model of Caco2 cells was constructed and the cells were divided into Control, LPS and LPS+CYP groups. The expression levels of tight junction protein and inflammatory factors in each group were assessed. Gene Ontology (GO) functional enrichment analysis was conducted to predict the possible pathways of action and potential molecular mechanisms of CYP, and to verify them in vivo and in vitro ., Results: In the in vivo study, compared with those of the TNBS group, the body mass and colon length of mice in the CYP group and the 5-ASA group were significantly increased, while the disease activity scores and histological inflammation scores were significantly decreased ( P <0.05). The level of lucifcein-glucan isothiocyanate and the bacterial translocation rate (in the liver, the spleen, and mesenteric lymph nodes) were significantly decreased, while the transepithelial electric resistance (TEER) value and the expression levels of zonula occluden protein-1 (ZO-1), and claudin-1 were significantly increased ( P <0.05). The expression of inflammatory factors was significantly decreased ( P <0.05). In the in vitro study, compared with those of the LPS group, the TEER value and the expression of ZO-1 and claudin-1 in the Caco2 cells in the LPS+CYP group were significantly increased ( P <0.05). The expression of inflammatory factors was significantly decreased ( P <0.05). Enrichment analysis showed that CYP was correlated with inflammatory response ( P <0.001). Western blot results showed that CYP could significantly reduce the expression of key proteins in toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway in vivo and in vitro ( P <0.05)., Conclusion: CYP may protect the intestinal barrier by antagonizing the inflammatory response of the intestinal mucosa through regulating the expression of the TLR4/NF-κB signaling pathway, thereby alleviating TNBS-induced CD-like colitis in mice., Competing Interests: 利益冲突　所有作者均声明不存在利益冲突, (© 2024《四川大学学报（医学版）》编辑部 版权所有Copyright ©2024 Editorial Office of Journal of Sichuan University (Medical Sciences).)

Objective: Radioactive intestinal injury is a common complication during radiotherapy of tumors. The aim of this study is to observe the effect of ionizing radiation on short-term changes in intestinal bile acids and to investigate the radioprotective effect of bile acids on intestinal cells., Methods: A rat model of small intestinal injury was constructed by exposing the abdomen of the rats to daily irradiation at 2 Gy for 4 d in succession. The bile acids were quantified using metabolomics analysis. IEC-6 cells, a small intestinal epithelial cell line, were divided into a dimethyl sulfoxide (DMSO) control group receiving DMSO and 0 Gy irradiation, a glycoursodeoxycholic acid (GUDCA) experimental group receiving GUDCA and 0 Gy irradiation, a DMSO irradiation group receiving DMSO and 10 Gy irradiation, and a GUDCA irradiation group receiving GUDCA and 10 Gy irradiation. Cell viability and cytotoxicity was assessed by CCK-8 assay test. The apoptosis rate of cells was determined by flow cytometry. The colony formation rate and the radiosensitivity of the cells were determined by colony formation assay on solid media. The expression levels of proteins associated with cell death were determined using Western blot., Results: After exposure to irradiation, the small intestine tissues of the rats showed typical radioactive intestinal injury. In addition, various bile acids showed fluctuation before and after irradiation. Among the bile acids, GUDCA increased significantly at 3 d after irradiation, but returned to the pre-irradiation level at 7 d after irradiation. Compared with the control group, after GUDCA treatment at 20 μmol/L for 24 h, the cell viability rate after irradiation was significantly higher than that of the DMSO group ( P <0.05); the expression levels of the proteins, including PARP, caspase-3, RIP, and GSDMD, were significantly lower than those in the control group ( P <0.05). After GUDCA treatment at 20 μmol/L for 24 h and 48 h, the cell apoptosis rate of the cells after irradiation was lower than that of the DMSO group ( P <0.05). Compared with the DMSO control group, the colony formation ability of the GUDCA experimental group was stronger than that of the DMSO group after irradiation at 0, 2, 4, and 6 Gy ( P <0.05). D 0 , or the mean lethal dose, of the GUDCA group was 6.374, while that of the DMSO group was 4.572. Compared with the DMSO control group, the D 0 value of the GUDCA treatment group increased, and the sensitization enhancement ratio (SER) was 0.717., Conclusion: After exposing the abdomen of rats to irradiation, the intestinal bile acid metabolism of the rats will change significantly, and GUDCA can produce radioprotective effects on intestinal cells to a certain extent., Competing Interests: 利益冲突　本文作者张舒羽是本刊编委会编委。该文在编辑评审过程中所有流程严格按照期刊政策进行，且未经其本人经手处理。除此之外，所有作者声明不存在利益冲突。, (© 2024《四川大学学报（医学版）》编辑部 版权所有Copyright ©2024 Editorial Office of Journal of Sichuan University (Medical Sciences).)

Objective: To investigate the effect and molecular mechanism of isolongifolene (ISO) on the apoptosis of intestinal epithelial cells and 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced Crohn's disease (CD)-like colitis in mice., Methods: In the animal experiments, mice were randomly assigned to the wild type (WT) group, TNBS group and TNBS+ISO group, with 8 mice in each group. Colitis models of mice were established in the TNBS group and the TNBS+ISO group by rectal injection of TNBS. After modeling, the mice in the TNBS+ISO group were given ISO intervention via intragastric gavage (10 mg/kg), and the other two groups were given the same amount of normal saline via intragastric gavage. The mice were sacrificed on the 7th day. The changes in body mass, disease activity scores (DAI), and the colon length of mice were measured, and transepithelial electrical resistance (TEER) of the colon tissues was determined. The score of colon inflammation was calculated according to HE staining. The levels of intestinal mucosal inflammatory factors, including tumor necrosis factor alpha (TNF-α), interferon (IFN)-γ, interleukin (IL)-1β, and IL-6, were measured by RT-PCR and ELISA. The apoptosis of colon tissue cells was determined by TUNEL assay. The expressions of apoptotic proteins (cleaved caspase-3/caspase-3 and Bax), an anti-apoptotic protein (Bcl-2), and tight junction proteins (ZO-1 and claudin-1) were detected by Western blot and immunofluorescence. In the cell experiment, TNF-α was used to induce intestinal epithelial cell Caco-2 apoptosis model, which was treated with ISO. Then, intervention with the AMPK inhibitor Compound C was given. TUNEL assay, Western blot assay, and immunofluorescence assay were performed to measure apoptosis and the expression of apoptosis proteins in the Caco-2 cells. Gene Ontology (GO) enrichment analysis was performed to predict the biological function of ISO. Then, the mechanism involved was verified by examination of the mice and Caco-2 cells. Western blot was performed to determine the expression levels of p-AMPK/AMPK and p-PGC1α in the colon tissues from the mice of different groups and Caco-2 cells. The apoptosis of the cells was determined by TUNEL assay., Results: According to the results of the animal experiment, ISO could alleviate experimental colitis and intestinal barrier dysfunction, leading to improvements in body mass loss, colon length shortening, DAI score, inflammatory rating, and TEER values (all P <0.05) in mice. Furthermore, ISO decreased the expression of pro-inflammatory factors TNF-α, IFN-γ, IL-1β, and IL-6 and increased the expression of the tight junction proteins ZO-1 and claudin-1 (all P <0.05). In the cell experiment, in a TNF-α-induced intestinal epithelial cell model, ISO was also found to protect intestinal barrier against damage. ISO reduced the proportion of apoptotic intestinal epithelial cells, reduced the expression of cleaved-caspase-3/caspase-3 and Bax, and upregulated the level of Bcl-2 (all P <0.05). GO enrichment predictive analysis showed that the role of ISO in improving CD-like enteritis might be associated with the negative regulation of apoptosis. Verification of the mechanism showed that the expression of p-AMPK and p-PGC1α in the mice colon tissue was significantly upregulated after ISO intervention ( P <0.05). In contrast, the AMPK inhibitor Compound C increased the apoptosis rate of ISO-treated Caco-2 cells and decreased the relative expression levels of ZO-1 and claudin-1 ( P <0.05)., Conclusion: ISO reduces intestinal epithelial cell apoptosis at least in part by activating AMPK/PGC1α signaling pathway, thereby alleviating TNBS-induced intestinal barrier dysfunction and CD-like colitis in mice., Competing Interests: 利益冲突　所有作者均声明不存在利益冲突, (© 2024《四川大学学报（医学版）》编辑部 版权所有Copyright ©2024 Editorial Office of Journal of Sichuan University (Medical Sciences).)

Objective: To investigate the mechanism by which swertiamarin (STM) ameliorates CD-like colitis in mice., Methods: A Caco-2 cell model of TNF- α -stimulated apoptosis was established and divided into three groups: Con, TNF- α and STM, and the effects of STM on apoptosis and barrier function were assessed by Tunel staining, western blotting, immunofluorescence, and transepithelial electric resistance (TEER). A mouse model of 2, 4, 6-trinitrobenzenesulfonic acid (TNBS) -induced CD-like colitis was established to assess the effects of STM on colitis, intestinal barrier function and epithelial cell apoptosis. The regulatory role of the PI3K/AKT pathway in STM-induced resistance to intestinal epithelial cell apoptosis was investigated in both the cell model and mouse models., Results: TUNEL staining showed that in Caco-2 cells with TNF- α stimulation, STM treatment significantly reduced the percentage of TUNEL-stained cells ( P <0.05). STM obviously reduced TNF- α -induced enhancement of cleaved-caspase 3 and Bax expressions ( P <0.05), increased Bcl-2 expression ( P <0.05), protected intestinal barrier integrity and function by restoring transepithelial electrical resistance (TEER) of the cells, promoted normal localization and expressions of the tight junction proteins (ZO1 and claudin 1) ( P <0.05), and inhibited the expression of pro-inflammatory factors (IL-6 and CCL3) ( P <0.05) in TNF- α -stimulated Caco-2 cells. In the mouse models, STM significantly alleviated TNBS-induced CD-like colitis and intestinal barrier dysfunction ( P <0.05) as shown by improved weight loss, lowered Disease Activity Index (DAI) score and inflammation score, reduction of IL-6 and CCL3 release, and restoration of intestinal barrier permeability, colonic TEER, bacterial translocation, and localization and expressions of the tight junction proteins. Mechanistically, STM inhibited the expressions of p-PI3K and p-AKT in both the cell model and mouse model( P <0.05), and treatment with 740Y-P (a PI3K/AKT pathway activator) significantly attenuated the inhibitory effect of STM on TNF- α -induced apoptosis in Caco-2 cells ( P <0.05)., Conclusion: STM inhibits intestinal epithelial cell apoptosis at least in part by suppressing activation of the PI3K/AKT pathway to ameliorate intestinal barrier dysfunction and colitis in mice.

This study explores the effects and mechanisms of Modified Xiaoyao Powder on the intestinal barrier and intestinal flora in mice with metabolic associated fatty liver disease(MAFLD) based on the &quot; gut-liver axis&quot;. Sixty male C57BL/6 mice were randomly divided into the normal group, model group, bifidobacterium tetrad tablet group(SQ), and Modified Xiaoyao Powder groups with low,medium and high doses(XL, XM, XH), with 10 mice in each group. All the mice were administrated with a high-fat diet to build the MAFLD model except the normal group and then treated with related drugs for 12 weeks. Body mass, liver wet weight, and liver index were detected. Serum aspartate aminotransferase(AST), alanine aminotransferase(ALT), total cholesterol(TC), triacylglycerol(TG), low density lipoprotein cholesterol(LDL-C), high density lipoprotein cholesterol(HDL-C), and lipopolysaccharide(LPS)levels were detected using the biochemical kits. The contents of tumor necrosis factor-α(TNF-α) and interleukin(IL-6) in the liver were tested simultaneously. The morphological changes of the liver and intestine were observed using hematoxylin-eosin(HE) staining and oil red O staining. The goblet cells in the ileum were detected by periodic acid Schiff and alcian blue stain(AB-PAS) staining.The expression of zonula occludens-1(ZO-1), recombinant occludin(occludin), and recombinant claudin 1(claudin-1) in ileum and colon were detected by immunohistochemistry and Western blot. The changes of intestinal flora in mice were analyzed by 16S rRNA gene sequencing. The results showed that compared with the normal group, body weight, liver wet weight and liver index in the model group increased. The contents of TC, TG, ALT, AST, LDL-C, and LPS in the serum of the model group increased, while HDL-C decreased. Meanwhile, the contents of TNF-α and IL-6 in liver tissue increased and liver lipid accumulation increased, indicating successful model induction. Compared with the model group, body weight, liver wet weight, and liver index were decreased in XM,XH groups and SQ group. Serum levels of TC, TG, LDL-C, ALT and AST in XM group and SQ group were significantly decreased,and HDL-C levels were increased. The levels of IL-6, TNF-α in liver tissue and serum LPS in the XL, XM groups and SQ group were significantly decreased. The protein expression of claudin-1, occludin and ZO-1 in XL, XM groups and SQ group were increased. The analysis of intestinal flora showed that compared with the model group, Modified Xiaoyao Powder with a medium dose could significantly improve the richness and diversity of intestinal flora in mice. At the phylum level, the Firmicutes/Bacteroidetes(F/B) ratio decreased; at the genus level, Lactobacillus, Brautella, Bacteroides, and Ackermannia increased, while Prevotella, Desulfovibrio and Turicibacter decreased. The main differential species were Odorbacteraceaeae and Peptostreptococcaceae. In conclusion, Modified Xiaoyao Powder could inhibit inflammation, regulate intestinal flora homeostasis, and promote the repair of the intestinal mucosal barrier in mice with MAFLD.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by continuous inflammation and ulcer formation in the intestinal mucosa.Its pathogenesis involves immune dysfunction,dysbiosis of gut microbiota,and mucosal damage caused by inflammation.Ferroptosis is an iron-dependent form of cell death regulated by disturbances in iron metabolism,lipid peroxidation,and depletion of glutathione (GSH).Studies have indicated that ferroptosis plays a crucial role in the pathogenesis of UC,particularly in regulating inflammatory responses and damaging intestinal epithelial cells.This article reviews the regulatory mechanisms and roles of ferroptosis in UC and discusses the potential therapeutic strategies to alleviate UC symptoms by modulating iron metabolism,reducing lipid peroxidation,and maintaining GSH levels,providing new targets and directions for the diagnosis and treatment of UC.

This study aims to explore the improvement effect of Sijunzi Decoction on intestinal barrier in diabetic mice. A type 2 diabetes mellitus(T2DM) model was established in C57BL/6J mice by feeding them with high-sugar and high-fat diet combined with streptozotocin(STZ). The T2DM mice were randomly divided into a control group, a T2DM group, a donepezil(DON) group, a rosiglitazone(RGZ) group, and Sijunzi Decoction groups(7. 5, 15, and 30 g·kg~(-1)), and orally administered for six weeks. The body weight and fasting plasma glucose(FBG) of mice were recorded. Fasting plasma insulin(FINS) and insulin resistance index(HOMA-IR) were observed to assess insulin resistance(IR). Intestinal flora and levels of serotonin(5-HT), lipopolysaccharide(LPS), and short-chain fatty acids(SCFAs) in serum were analyzed. Changes in colonic structure and tight junction proteins occludin, claudin-1,and ZO-1 were observed through HE staining and immunohistochemistry. Spontaneous alternation test was conducted to observe the effect on spatial memory ability. Compared with the results in the control group, FBG and HOMA-IR in the T2DM group were significantly increased(P&lt; 0. 01); species richness index(Sobs index), Shannon diversity index(Shannon index), and species abundance estimate index(Chao index) were decreased; LPS was significantly increased(P&lt; 0. 001), while the levels of 5-HT,SCFAs, occludin, claudin-1, and ZO-1 were significantly decreased(P&lt; 0. 01), indicating impaired colonic barrier function;spontaneous alternation accuracy was significantly decreased(P&lt;0. 05). After 6 weeks of Sijunzi Decoction treatment, compared with the results in the T2DM group, FBG and HOMA-IR in the Sijunzi Decoction 15 g·kg~(-1) group were significantly decreased(P&lt;0. 01);Sobs index, Shannon index, and Chao index were increased; LPS was significantly decreased(P&lt;0. 01), while the levels of 5-HT,SCFAs, occludin, claudin-1, and ZO-1 were significantly increased(P&lt; 0. 05), indicating improved colonic barrier function;spontaneous alternation accuracy was increased(P&lt;0. 001). In conclusion, Sijunzi Decoction has the effect of improving intestinal barrier in diabetic mice.

Objective: To investigate the involvement of the high mobility group box protein B1 (HMGB1)-Toll-like receptor 2 (TLR2)/TLR4-nuclear factor κB (NF-κB) pathway in the intestinal mucosal injury induced by Cryptosporidium parvum infection, and to examine the effect of oxymatrine (OMT) on C. parvum infection in mice., Methods: Forty SPF 4-week-old BALB/c mice were randomly divided into four groups, including the control group, infection group, glycyrrhizin (GA) group and OMT group. Each mouse was orally administered with 1 × 10 5 C. parvum oocysts one week in the infection, GA and OMT groups following dexamethasone-induced immunosuppression to model C. parvum intestinal infections in mice. Upon successful modeling, mice in the GA group were intraperitoneally injected with GA at a daily dose of 25.9 mL/kg for successive two weeks, and animals in the OMT group were orally administered OMT at a daily dose of 50 mg/kg for successive two weeks, while mice in the control group were given normal food and water. All mice were sacrificed two weeks post-treatment, and proximal jejunal tissues were sampled. The pathological changes of mouse intestinal mucosal specimens were observed using hematoxylin-eosin (HE) staining, and the mouse intestinal villous height, intestinal crypt depth and the ratio of intestinal villous height to intestinal crypt depth were measured. The occludin and zonula occludens protein 1 (ZO1) expression was determined in mouse intestinal epithelial cells using immunohistochemistry, and the relative expression of HMGB1 , TLR2 , TLR4 , myeloid differentiation primary response gene 88 ( MyD88 ) and NF-κB p65 mRNA was quantified in mouse jejunal tissues using quantitative real-time PCR (qPCR) assay., Results: HE staining showed that the mouse intestinal villi were obviously atrophic, shortened, and detached, and the submucosal layer of the mouse intestine was edematous in the infection group as compared with the control group, while the mouse intestinal villi tended to be structurally intact and neatly arranged in the GA and OMT groups. There were significant differences among the four groups in terms of the mouse intestinal villous height ( F = 6.207, P = 0.000 5), intestinal crypt depth ( F = 6.903, P = 0.000 3) and the ratio of intestinal villous height to intestinal crypt depth ( F = 37.190, P < 0.000 1). The mouse intestinal villous height was lower in the infection group than in the control group [(321.9 ± 41.1) μm vs. (399.5 ± 30.9) μm; t = 4.178, P < 0.01] and the GA group [(321.9 ± 41.1) μm vs. (383.7 ± 42.7) μm; t = 3.130, P < 0.01], and the mouse intestinal crypt depth was greater in the infection group [(185.0 ± 35.9) μm] than in the control group [(128.4 ± 23.6) μm] ( t = 3.877, P < 0.01) and GA group [(143.3 ± 24.7) μm] ( t = 2.710, P < 0.05). The mouse intestinal villous height was greater in the OMT group [(375.3 ± 22.9) μm] than in the infection group ( t = 3.888, P < 0.01), and there was no significant difference in mouse intestinal villous height between the OMT group and the control group ( t = 1.989, P > 0.05). The mouse intestinal crypt depth was significantly lower in the OMT group [(121.5 ± 27.3) μm] than in the infection group ( t = 4.133, P < 0.01), and there was no significant difference in mouse intestinal crypt depth between the OMT group and the control group ( t = 0.575, P > 0.05). The ratio of the mouse intestinal villous height to intestinal crypt depth was significantly lower in the infection group (1.8 ± 0.2) than in the control group (3.1 ± 0.3) ( t = 10.540, P < 0.01) and the GA group (2.7 ± 0.3) ( t = 7.370, P < 0.01), and the ratio of the mouse intestinal villous height to intestinal crypt depth was significantly higher in the OMT group (3.1 ± 0.2) than in the infection group ( t = 15.020, P < 0.01); however, there was no significant difference in the ratio of the mouse intestinal villous height to intestinal crypt depth between the OMT group and the control group ( t = 0.404, P > 0.05). Immunohistochemical staining showed significant differences among the four groups in terms of occludin ( F = 28.031, P < 0.000 1) and ZO1 expression ( F = 14.122, P < 0.000 1) in mouse intestinal epithelial cells. The proportion of positive occluding expression was significantly lower in mouse intestinal epithelial cells in the infection group than in the control group [(14.3 ± 4.5)% vs. (28.3 ± 0.5)%; t = 3.810, P < 0.01], and the proportions of positive occluding expression were significantly higher in mouse intestinal epithelial cells in the GA group [(30.3 ± 1.3)%] and OMT group [(25.8 ± 1.5)%] than in the infection group ( t = 7.620 and 5.391, both P values < 0.01); however, there was no significant differences in the proportion of positive occluding expression in mouse intestinal epithelial cells between the GA or OMT groups and the control group ( t = 1.791 and 2.033, both P values > 0.05). The proportion of positive ZO1 expression was significantly lower in mouse intestinal epithelial cells in the infection group than in the control group [(14.4 ± 1.8)% vs. (24.2 ± 2.8)%; t = 4.485, P < 0.01], and the proportions of positive ZO1 expression were significantly higher in mouse intestinal epithelial cells in the GA group [(24.1 ± 2.3)%] ( t = 5.159, P < 0.01) and OMT group than in the infection group [(22.5 ± 1.9)%] ( t = 4.441, P < 0.05); however, there were no significant differences in the proportion of positive ZO1 expression in mouse intestinal epithelial cells between the GA or OMT groups and the control group ( t = 0.037 and 0.742, both P values > 0.05). qPCR assay showed significant differences among the four groups in terms of HMGB1 ( F = 21.980, P < 0.000 1), TLR2 ( F = 20.630, P < 0.000 1), TLR4 ( F = 17.000, P = 0.000 6), MyD88 ( F = 8.907, P = 0.000 5) and NF-κB p65 mRNA expression in mouse jejunal tissues ( F = 8.889, P = 0.000 7). The relative expression of HMGB1 [(5.97 ± 1.07) vs. (1.05 ± 0.07); t = 6.482, P < 0.05] 、 TLR2 [(5.92 ± 1.29) vs. (1.10 ± 0.14); t = 5.272, P < 0.05] 、 TLR4 [(5.96 ± 1.50) vs. (1.02 ± 0.03); t = 4.644, P < 0.05] 、 MyD88 [(3.00 ± 1.26) vs. (1.02 ± 0.05); t = 2.734, P < 0.05] and NF-κB p65 mRNA [(2.33 ± 0.72) vs. (1.04 ± 0.06); t = 2.665, P < 0.05] was all significantly higher in mouse jejunal tissues in the infection group than in the control group. A significant reduction was detected in the relative expression of HMGB1 (0.63 ± 0.01), TLR2 (0.42 ± 0.10), TLR4 (0.35 ± 0.07), MyD88 (0.70 ± 0.11) and NF-κB p65 mRNA (0.75 ± 0.01) in mouse jejunal tissues in the GA group relative to the control group ( t = 8.629, 5.830, 11.500, 4.729 and 6.898, all P values < 0.05), and the relative expression of HMGB1 , TLR2 , TLR4 , MyD88 and NF-κB p65 mRNA significantly reduced in mouse jejunal tissues in the GA group as compared to the infection group ( t = 7.052, 6.035, 4.084, 3.165 and 3.274, all P values < 0.05). In addition, the relative expression of HMGB1 (1.14 ± 0.60), TLR2 (1.00 ± 0.24), TLR4 (1.14 ± 0.07), MyD88 (0.96 ± 0.25) and N F-κ B p65 mRNA (1.12 ± 0.17) was significantly lower in mouse jejunal tissues in the OMT group than in the infection group ( t = 7.059, 5.320, 3.510, 3.466 and 3.273, all P values < 0.05); however, there were no significant differences between the OMT and control groups in terms of relative expression of HMGB1 , TLR2 , TLR4 , MyD88 or NF-κB p65 mRNA in mouse jejunal tissues ( t = 0.239, 0.518, 1.887, 0.427 and 0.641, all P values > 0.05)., Conclusions: C. parvum infection causes intestinal inflammatory responses and destruction of intestinal mucosal barrier through up-regulating of the HMGB1-TLR2/TLR4-NF-κB pathway. OMT may suppress the intestinal inflammation and repair the intestinal mucosal barrier through inhibiting the activity of the HMGB1-TLR2/TLR4-NF-κB pathway.

Objective: To investigate the protective effect of berberine hydrochloride on intestinal mucosal barrier damage in sepsis rats and its mechanism., Methods: Forty-eight male SD rats were divided into a control group (Sham group, 6 cases), a sepsis model group (LPS group, 14 cases), a berberine hydrochloride intervention group (Ber group, 14 cases), and a Notch signaling pathway inhibition group (DAPT group, 14 cases) according to random number table method. The DAPT group was intraperitoneally injected with 5 mg/kg Notch signaling pathway inhibition DAPT 2 hours before modeling. The sepsis model was established by intraperitoneal injection of 10 mg/kg lipopolysaccharide (LPS); Sham group was injected with an equal amount of saline (2 mL). The Ber group and DAPT group were treated with gavage of 50 mg/kg berberine hydrochloride 2 hours after modeling; Sham group and LPS group were treated with gavage of an equal amount of saline (2 mL). The temperature, weight, behavior and survival rate of rats were observed at 0, 6, 12 and 24 hours of modeling. After 24 hours of modeling, abdominal aortic blood was collected under anesthesia, and intestinal tissues were obtained after euthanasia. The pathological changes of ileum were observed under light microscope. The ultrastructure of ileum was observed under transmission electron microscope. Enzyme linked immunosorbent assay (ELISA) was used to detect the levels of serum diamine oxidase (DAO), intestinal fatty acid binding protein (iFABP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). Real time-polymerase chain reaction (RT-PCR) and Western blotting were used to detect the mRNA and protein expressions of tight junction proteins (Occludin and Claudin1), Notch1 and their downstream target signals in the ileum tissue., Results: After 24 hours of modeling, compared with the Sham group, the LPS group, Ber group, and DAPT group showed a decrease in weight and an increase in temperature. Among them, the LPS group showed the most significant changes, followed by the DAPT group, and the Ber group showed the least significant changes. The survival rates of the LPS group, Ber group, and DAPT group were all lower than those of the Sham group [42.9% (6/14), 57.1% (8/14), 57.1% (8/14) vs. 100% (6/6)], and six rats were taken from each group for subsequent testing. Macroscopic observation of the intestine showed that the LPS group had the most severe edema in the ileum tissue and abdominal bleeding, with significant improvement in the Ber group and followed by the DAPT group. Under the light microscope, the LPS group showed disordered arrangement of glandular tissue in the ileum mucosa, significantly reduced goblet cells, and extensive infiltration of inflammatory cells, which were significantly improved in the Ber group but less improved in the DAPT group. Under electron microscopy, the LPS group showed extensive shedding of ileal microvilli and severe damage to the tight junction complex structure of intestinal epithelial cells, which was significantly improved in the Ber group but less improved in the DAPT group. The levels of serum DAO, iFABP, TNF-α, IL-6 in the LPS group were significantly higher than those in the Sham group, while the above indicators in the Ber group were significantly lower than those in the LPS group [DAO (μg/L): 4.94±0.44 vs. 6.53±0.49, iFABP (ng/L): 709.67±176.97 vs. 1 417.71±431.44, TNF-α (ng/L): 74.70±8.15 vs. 110.36±3.51, IL-6 (ng/L): 77.34±9.80 vs. 101.65±6.92, all P < 0.01], while the above indicators in the DAPT group were significantly higher than those in the Ber group. The results of RT-PCR and Western blotting showed that the mRNA and protein expressions of Occludin, Claudin1, Notch1, and Hes1 in the ileum tissue of LPS group rats were decreased compared to the Sham group, which were significantly increased in the Ber group compared with the LPS group [mRNA expression: Occludin mRNA (2 -ΔΔCt ): 1.61±0.74 vs. 0.30±0.12, Claudin1 mRNA (2 -ΔΔCt ): 1.97±0.37 vs. 0.58±0.14, Notch1 mRNA (2 -ΔΔCt ): 1.29±0.29 vs. 0.36±0.10, Hes1 mRNA (2 -ΔΔCt ): 1.22±0.39 vs. 0.27±0.04; protein expression: Occludin/GAPDH: 1.17±0.14 vs. 0.74±0.04, Claudin1/GAPDH: 1.14±0.06 vs. 0.58±0.10, Notch1/GAPDH: 0.87±0.11 vs. 0.56±0.09, Hes1/GAPDH: 1.02±0.13 vs. 0.62±0.01; all P < 0.05], while those in the DAPT group were significantly lower than those in the Ber group., Conclusions: Early use of berberine hydrochloride can significantly improve intestinal mucosal barrier damage in sepsis rats, and its mechanism may be related to inhibiting inflammatory response and regulating the expression of intestinal mechanical barrier tight junction protein through Notch1 signal.

Objective To explore the relationship between the expression levels of microRNA-155 (miR-155) and suppressor of cytokine signaling 1 (SOCS1) in the colonic mucosal tissue of patients with ulcerative colitis (UC) and the severity of the disease.Methods A total of 130 UC patients admitted to the Second Affiliated Hospital of Hebei North University from September 2021 to June 2023 were selected.According to the modified Mayo score system,the patients were assigned into an active stage group ( n =85) and a remission stage group ( n =45).According to the modified Truelove and Witts classification criteria,the UC patients at the active stage were assigned into a mild group ( n =35),a moderate group ( n =30),and a severe group ( n =20).A total of 90 healthy individuals who underwent colonoscopy for physical examination or those who had normal colonoscopy results after single polypectomy and excluded other diseases were selected as the control group.The colonic mucosal tissues of UC patients with obvious lesions and the colonic mucosal tissue 20 cm away from the anus of the control group were collected.The levels of miR-155 and SOCS1 mRNA in tissues were determined by fluorescence quantitative PCR,and the expression of SOCS1 protein in tissues was determined by immunohistochemistry.The correlations of the levels of miR-155 and SOCS1 mRNA in the colonic mucosal tissue with the modified Mayo score of UC patients were analyzed.The values of the levels of miR-155 and SOCS1 mRNA in predicting the occurrence of severe illness in the UC patients at the active stage were evaluated.Results Compared with the control group and the remission stage group,the active stage group showed up-regulated expression level of miR-155,down-regulated level of SOCS1 mRNA,and decreased positive rate of SOCS1 protein in the colonic mucosal tissue (all P <0.001).The expression level of miR-155 and modified Mayo score in colonic mucosal tissues of UC patients at the active stage increased,while the mRNA level of SOCS1 was down-regulated as the disease evolved from being mild to severe (all P <0.001).The modified Mayo score was positively correlated with the miR-155 level and negative correlated with the mRNA level of SOCS1 in colonic mucosal tissues of UC patients (all P <0.001).The high miR-155 level ( OR =2.762,95% CI =1.284-5.944, P =0.009),low mRNA level of SOCS1 ( OR =2.617,95% CI =1.302-5.258, P =0.007),and modified Mayo score≥12 points ( OR =3.232,95% CI =1.450-7.204, P =0.004) were all risk factors for severe disease in the UC patients at the active stage.The area under curve of miR-155 combined with SOCS1 mRNA in predicting severe illness in the UC patients at the active stage was 0.920.Conclusions The expression levels of miR-155 and SOCS1 mRNA were correlated with the disease severity in the UC patients at the active stage.The combination of the two indicators demonstrates good performance in predicting the occurrence of severe illness in UC patients at the active stage.

Infection is a common medical problem at present. Different pathogens can lead to different infections. Severe infections can ultimately lead to sepsis, resulting in multiple organ dysfunction and the high mortality of patients. Therefore, studying the occurrence and development of severe infections is essential to improve the survival rate of patients. More and more studies have revealed the important role of connection between intestine and liver in infectious diseases. The maintenance of intestinal mechanical barrier and biological barrier function and the regulation of intestinal flora metabolites can reduce infectious liver injury. Bile acids are important metabolites in the liver, which can inhibit the progression of certain infectious intestinal injuries and promote intestinal damage caused by certain pathogens. In this article, the mechanism of action of the intestinal-liver axis in infection was reviewed to find a new target for the treatment of clinical infection.

Objectives: To investigate the effect of Peitu Yimu(strengthening spleen and soothing liver) acupuncture on intestinal mucosal barrier function and corticotropin-releasing factor (CRF)/CRF receptor 1 (CRFR1) pathway in rats with diarrhea-predominant irritable bowel syndrome (IBS-D), so as to explore its underlying mechanism in alleviating IBS-D., Methods: Forty female SD rats were randomly divided into blank, model, electroacupuncture (EA), and agonist groups, with 10 rats in each group. Except for the blank group, rats in the other groups were given folium sennae infusion by gavage combined with chronic unpredictable mild stress to establish IBS-D model. Rats in the EA group received acupuncture at "Tianshu"(ST25) and EA at "Zusanli"(ST36) and "Taichong"(LR3) (2 Hz/15 Hz) on one side for 20 min, with the side chosen alternately every other day, for 14 days after modeling. Rats in the agonist group received acupuncture 30 min after intravenous injection of CRFR1 agonist urocortin, with the same manipulation method and time as the EA group. Before and after intervention, visceral pain threshold and stool Bristol scores were measured. Elevated plus maze test and open field test were used to detect anxiety and depression like behavior of rats. ELISA was used to detect the contents of CRF and CRFR1 in rats serum. Immunohistochemistry was used to detect the positive expressions of CRF, CRFR1, zonula occludens protein 1(ZO-1), occlusal protein(Occludin), and closure protein 1 (Claudin-1) in colon tissue., Results: Compared with the blank group, the visceral pain threshold, open arm time percentage (OT%), total distance of movement in the open field test, and positive expression of ZO-1, Occludin, and Claudin-1 in colon were decreased ( P <0.01, P <0.05), while Bristol stool scores, serum CRF and CRFR1 contents, and positive expressions of CRF and CRFR1 in colon were increased ( P <0.01) in the model group. After intervention and compared with the model group, the visceral pain threshold, OT%, total distance of movement in the open field test, and positive expressions of ZO-1, Occludin, and Claudin-1 in colon were increased ( P <0.05, P <0.01), while Bristol stool scores, serum CRF and CRFR1 contents, and positive expressions of CRF and CRFR1 in colon were decreased ( P <0.01) in the EA group；the Bristol stool scores, serum CRF content, and CRF positive expression in colon were significantly decreased in the agonist group ( P <0.01)., Conclusions: Peitu Yimu acupuncture can significantly improve visceral hypersensitivity and anxiety-depression state in IBS-D rats. Its mechanism may be related to the inhibition of CRF/CRFR1 pathway and restoration of intestinal tight junction protein expressions.

Objective: To analyze the impact of cecal ligation and puncture (CLP)-induced sepsis on the proliferation and differentiation of intestinal epithelial cells., Methods: (1) Animal experiment: sixteen male C57BL/6 mice were divided into sham operation group (Sham group) and CLP-induced sepsis model group (CLP group) by random number table method, with 8 mice in each group. After 5 days of operation, the jejunal tissues were taken for determination of leucine-rich-repeat-containing G-protein-coupled receptor 5 (LGR5) and intestinal alkaline phosphatase (IAP) by polymerase chain reaction (PCR). The translation of LGR5 was detected by Western blotting. The expression of proliferating cell nuclear antigen (Ki67) was analyzed by immunohistochemistry. IAP level was detected by modified calcium cobalt staining and colorimetry. Immunofluorescence staining was used to detect the expression of Paneth cell marker molecule lysozyme 1 (LYZ1) and goblet cell marker molecule mucin 2 (MUC2). (2) Cell experiment: IEC6 cells in logarithmic growth stage were divided into blank control group and lipopolysaccharide (LPS) group (LPS 5 μg/mL). Twenty-four hours after treatment, PCR and Western blotting were used to analyze the transcription and translation of LGR5. The proliferation of IEC6 cells were detected by 5-ethynyl-2'-deoxyuridine (EdU) staining. The transcription and translation of IAP were detected by PCR and colorimetric method respectively., Results: (1) Animal experiment: the immunohistochemical results showed that the positive rate of Ki67 staining in the jejunal tissue of CLP group was lower than that of Sham group [(41.7±2.5)% vs. (48.7±1.4)%, P = 0.01]. PCR and Western blotting results showed that there were no statistical differences in the mRNA and protein expressions of LGR5 in the jejunal tissue between the CLP group and Sham group (Lgr5 mRNA: 0.7±0.1 vs. 1.0±0.2, P = 0.11; LGR5/β-actin: 0.83±0.17 vs. 0.68±0.19, P = 0.24). The mRNA (0.4±0.1 vs. 1.0±0.1, P < 0.01) and protein (U/g: 47.3±6.0 vs. 73.1±15.3, P < 0.01) levels of IAP in the jejunal tissue were lower in CLP group. Immunofluorescence saining analysis showed that the expressions of LYZ1 and MUC2 in the CLP group were lower than those in the Sham group. (2) Cell experiment: PCR and Western blotting results showed that there was no significant difference in the expression of LGR5 between the LPS group and the blank control group (Lgr5 mRNA: 0.9±0.1 vs. 1.0±0.2, P = 0.33; LGR5/β-actin: 0.71±0.18 vs. 0.69±0.04, P = 0.81). The proliferation rate of IEC6 cells in the LPS group was lower than that in the blank control group, but there was no significant difference [positivity rate of EdU: (40.5±3.8)% vs. (46.5±3.6)%, P = 0.11]. The mRNA (0.5±0.1 vs. 1.0±0.2, P < 0.01) and protein (U/g: 15.0±4.0 vs. 41.2±10.4, P < 0.01) of IAP in the LPS group were lower than those in the blank control group., Conclusions: CLP-induced sepsis inhibits the proliferation and differentiation of intestinal epithelial cells, impairing the self-renewal ability of intestinal epithelium.

Objective: To investigate the expression level of Kruppel-like transcription factor family member KLF11 in intestinal mucosal tissues of Crohn's disease (CD) and its regulatory effect on intestinal inflammation in CD-like colitis., Methods: We examined KLF11 expression levels in diseased and normal colon mucosal tissues from 12 CD patients and 12 patients with colorectal cancer using immunofluorescence staining. KLF11 expression was also detected in the colon mucosal tissues of a mouse model of 2, 4, 6-trinitrobenesulfonic acid (TNBS)-induced colitis. A recombinant adenoviral vector was used to upregulate KLF11 expression in the mouse models and the changes in intestinal inflammation was observed. A Caco-2 cell model with stable KLF11 overexpression was constructed by lentiviral infection. The effect of KLF11 overexpression on expressions of JAK2/STAT3 signaling pathway proteins was investigated using immunoblotting in both the mouse and cell models. The mouse models were treated with coumermycin A1, a JAK2/STAT3 signaling pathway agonist, and the changes in intestinal inflammatory responses were observed., Results: The expression level of KLF11 was significantly lowered in both the clinical specimens of diseased colon mucosal tissues and the colon tissues of mice with TNBS-induced colitis ( P < 0.05). Adenovirus-mediated upregulation of KLF11 significantly improved intestinal inflammation and reduced the expression levels of inflammatory factors in the intestinal mucosa of the colitis mouse models ( P < 0.05). Overexpression of KLF11 significantly inhibited the expression levels of p-JAK2 and p-STAT3 in intestinal mucosal tissues of the mouse models and in Caco-2 cells ( P < 0.05). Treatment with coumermycin A1 obviously inhibited the effect of KLF11 upregulation for improving colitis and significantly increased the expression levels of inflammatory factors in the intestinal mucosa of the mouse models ( P < 0.05)., Conclusion: KLF11 is downregulated in the intestinal mucosa in CD, and upregulation of KLF11 can improve intestinal inflammation and reduce the production of inflammatory factors probably by inhibiting the JAK2/STAT3 signaling pathway.

The pathogenesis of inflammatory bowel disease (IBD) is not fully elucidated. However, it has been considered that inflammatory macrophages may be involved in the imbalance of the intestinal mucosal immunity to regulate several signaling pathways, leading to IBD progression. The ratio of M1 to M2 subtypes of activated macrophages tends to increase in the inflamed intestinal section. There are challenges in the diagnosis and treatment of IBD, such as unsatisfactory specificity of imaging findings, low drug accumulation in the intestinal lesions, unstable therapeutic efficacy, and drug-related systemic toxicity. Recently developed nanoparticles may provide a new approach for the diagnosis and treatment of IBD. Nanoparticles targeted to macrophages can be used as contrast agents to improve the imaging quality or used as a drug delivery vector to increase the therapeutic efficiency of IBD. This article reviews the research progress on macrophage-targeting nanoparticles for the diagnosis and treatment of IBD to provide a reference for further research and clinical application.

Objective: To observe the effect of herbal cake-partitioned moxibustion (Moxi) on the expressions of inflammatory factors and M1/M2 polarization in colonic mucosal macrophages in Crohn's disease (CD) rats, so as to explore its underlying mechanisms in the treatment of CD., Methods: Forty male SD rats were randomly divided into normal, model, Moxi and medication groups ( n =10). The CD model was established by enema of 2, 4, 6-trinitrobenzene sulfonic acid (TNBS) solution (5%TNBS∶50% alcohol=2∶1, 3 mL/kg), once every 7 days, 4 times altogether. For rats of the Moxi group, cake-partitioned moxibustion was given to "Tianshu" (ST25) and "Qihai" (CV6), two moxa-cones for each acupoint every time, once daily for 10 days. For rats of the medication group, intragastric perfusion of mesalazine solution was given twice daily for 10 days. After the treatment, the colonic mucosa tissue was sampled, and the macrophages were isolated, purified and cultured. The pathological changes of colon tissues were observed by H.E. staining. The ultrastructure of colon tissue was observed by transmission electron microscopy. The expression levels of α7nAChR, NF-κB p65 and TNF-α in colon mucosal macrophages were detected by Western blot. The number of M1 and M2 macrophages in colon mucosa was detected by flow cytometry and immunofluorescence assay., Results: Compared with the normal group, the colon tissue of rats presented huge ulceration and inflammatory manifestations, the junction of colon epithelial cells was loose, the structure of organelles was damaged; the expression level of α7nAChR in macrophages of colon mucosa was significantly decreased ( P <0.01), while the expression levels of NF-κB p65 and TNF-α, and the number of M1 and M2 macrophages were increased ( P <0.01, P <0.05) in the model group. In comparison with the model group, the morphology and structure of colon mucosa tissues of rats in Moxi and medication groups were improved; the expression level of α7nAChR, the number of M2 macrophage in colon mucosa were significantly increased ( P <0.01, P <0.05), while the expression levels of NF-κB p65 and TNF-α, and the number of M1 macrophage were significantly decreased ( P <0.01, P <0.05) in both the Moxi and medication groups., Conclusion: Herbal cake-partitioned moxibustion may inhibit NF-κB activation by up-regulating the expression level of α7nAChR to promote the polarization of macrophages from M1 to M2 type, and reduce the proportion of M1 macrophages, inhibit the expression of TNF-α in colonic mucosa of CD rats, so as to relieve the intestinal inflammation.

Purpose: To investigate the effect of outer membrane vesicles (OMVs) secreted by Fusobacterium nucleatum (F.n) on Claudin-4 of human oral keratinocytes (HOK) and oral epithelial barrier function., Methods: Fusobacterium nucleatum was cultured under anaerobic conditions. The OMVs were extracted by dialysis and characterized by nanosight and transmission electron microscopy (TEM). HOK were stimulated with OMVs at different mass concentrations(0-100 μg/mL) for 12 h, and stimulated with 100 μg/mL OMVs for 6 h and 12 h respectively. The expression of Claudin-4 at gene and protein level was analyzed by RT-qPCR and Western blotting. Inverted fluorescence microscope was used to observe co-localization of HOK and OMVs and localization and distribution of Claudin-4 protein. Human oral epithelial barrier was constructed by Transwell apical chamber. Transepithelial electrical resistance(TER) of barrier was measured with a transmembrane resistance measuring instrument(EVOM2), and the permeability of the barrier was evaluated by transmittance of fluorescein isothiocyanate-dextran(FD-4). Statistical analysis was performed with GraphPad Prism 8.0 software package., Results: Compared with the control group, the expression of Claudin-4 at protein and gene level in the HOK of OMVs stimulated group was significantly reduced (P＜0.05), and immunofluorescence showed that the continuity of Claudin-4 fluorescence among cells was destroyed. OMVs stimulation decreased TER value of oral epithelial barrier(P＜0.05) and increased the transmittance of FD-4(P＜0.05)., Conclusions: OMVs derived from Fusobacterium nucleatum may damage oral mucosal epithelial barrier function through inhibiting the expression of Claudin-4.

The intestinal barrier, a complex structure consisting of multiple layers of defense barriers, blocks the transfer of intestinal and foreign bacteria and their metabolites into the internal environment of the human body. Intestinal permeability can be used to evaluate the integrity of the intestinal barrier. Increased intestinal permeability has been observed in patients with depressive disorder. Some studies have reported an interaction between depressive disorder and intestinal barrier. Herein, we reviewed reported findings on the mechanisms of how systematic low-grade inflammation, vagal nerve dysfunction, and hypothalamic-pituitary-adrenal axis dysfunction cause changes in intestinal permeability in patients with depressive disorder and the pathogenic mechanism of how bacterial translocation caused by damaged intestinal barrier leads to depressive disorder. In addition, the potential mechanisms of how antidepressants improve intestinal permeability and how probiotics improve depressive disorder have been discussed., (Copyright© by Editorial Board of Journal of Sichuan University (Medical Sciences).)

Objective: To investigate the role of cholinergic anti-inflammatory pathway in the regulation of peptide transporter 1 (PepT1) expression in small intestinal epithelium of septic rats by Ghrelin., Methods: One hundred adult male Sprague-Dawley (SD) rats were randomly divided into sham operation group, sepsis group, sepsis+vagotomy group, sepsis+Ghrelin group, and sepsis+vagotomy+Ghrelin group, with 20 rats in each group. In the sham operation group, the cecum was separated after laparotomy, without ligation and perforation. In the sepsis group, the rats received cecal ligation puncture (CLP). In the sepsis+vagotomy group, the rats received CLP and vagotomy after laparotomy. In the sepsis+Ghrelin group, 100 μmol/L Ghrelin was intravenously injected after CLP immediately. The rats in the sepsis+vagotomy+Ghrelin group received CLP and vagotomy at the same time, then the Ghrelin was intravenously injected immediately with the same dose as the sepsis+Ghrelin group. Ten rats in each group were taken to observe their survival within 7 days. The remaining 10 rats were sacrificed 20 hours after the operation to obtain venous blood and small intestinal tissue. The condition of the abdominal intestine was observed. The injury of intestinal epithelial cells was observed with transmission electron microscopy. The contents of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in serum and small intestinal tissue were detected by enzyme-linked immunosorbent assay (ELISA). The brush border membrane vesicle (BBMV) was prepared, the levels of mRNA and protein expression of PepT1 in the small intestinal epithelium were detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and Western blotting., Results: All rats in the sham operation group survived at 7 days after operation. The 7-day cumulative survival rate of rats in the sepsis group was significantly lower than that in the sham operation group (20% vs. 100%, P < 0.05). The cumulative survival rate of rats after Ghrelin intervention was improved (compared with sepsis group: 40% vs. 20%, P < 0.05), but the protective effect of Ghrelin was weakened after vagotomy (compared with sepsis+Ghrelin group: 10% vs. 40%, P < 0.05). Compared with the sham operation group, in the sepsis group, the small intestine and cecum were dull red, the intestinal tubules were swollen and filled with gas, the intestinal epithelial cells were seriously injured under transmission electron microscopy, the levels of TNF-α and IL-1β in serum and small intestinal were significantly increased, and the expression levels of PepT1 mRNA and protein in the small intestinal epithelium were significantly decreased. It indicated that the sepsis rat model was successfully prepared. After vagotomy, the intestinal swelling and gas accumulation became worse in septic rats, leading to the death of all rats. Compared with the sepsis group, the abdominal situation in the sepsis+Ghrelin group was improved, the injury of intestinal epithelial cells was alleviated, the serum and small intestinal TNF-α and IL-1β were significantly decreased [serum TNF-α (ng/L): 253.27±23.32 vs. 287.90±19.48, small intestinal TNF-α (ng/L): 95.27±11.47 vs. 153.89±18.15, serum IL-1β (ng/L): 39.16±4.47 vs. 54.26±7.27, small intestinal IL-1β (ng/L): 28.47±4.13 vs. 42.26±2.59, all P < 0.05], and the expressions of PepT1 mRNA and protein in the small intestinal epithelium were significantly increased [PepT1 mRNA (2 -ΔΔCt ): 0.66±0.05 vs. 0.53±0.06, PepT1 protein (PepT1/GAPDH): 0.80±0.04 vs. 0.60±0.05, both P < 0.05]. Compared with the sepsis+Ghrelin group, after vagotomy in the sepsis+vagotomy+Ghrelin group, the effect of Ghrelin on reducing the release of inflammatory factors in sepsis rats was significantly reduced [serum TNF-α (ng/L): 276.58±19.88 vs. 253.27±23.32, small intestinal TNF-α (ng/L): 144.28±12.99 vs. 95.27±11.47, serum IL-1β (ng/L): 48.15±3.21 vs. 39.16±4.47, small intestinal IL-1β (ng/L): 38.75±4.49 vs. 28.47±4.13, all P < 0.05], the up-regulated effect on the expression of PepT1 in small intestinal epithelium was lost [PepT1 mRNA (2 -ΔΔCt ): 0.58±0.03 vs. 0.66±0.05, PepT1 protein (PepT1/GAPDH): 0.70±0.02 vs. 0.80±0.04, both P < 0.05], and the injury of small intestinal epithelial cells was worse., Conclusions: Ghrelin plays a protective role in sepsis by promoting cholinergic neurons to inhibit the release of inflammatory factors, thereby promoting the transcription and translation of PepT1.

Objective: To observe the effect of electroacupuncture (EA) at "Zusanli" (ST36) on apoptosis of intestinal T lymphocytes, translocation of intestinal bacteria and expression of intestinal Bcl-2 and Bax proteins and intestinal mucosal immune barrier in sepsis rats, so as to explore its underlying mechanism in relieving sepsis., Methods: SD rats were randomly divided into sham operation ( n =6), model ( n =15), non-meridian and non-acupoint (non-acupoint, n =15) and acupoint EA( n =15) groups by using random number table method. The sepsis model was established by using cecal ligation and perforation(CLP) method. EA (2 Hz, 2 mA) was applied to bilateral ST36 or non-acupoint for 30 min one hour after modeling, once every day for 3 days. The rats' general conditions and fatality rate in 3 days after modeling were recorded. The liver, spleen and mesenteric lymph nodes were taken for bacterial culture to detect the translocation rate of intestinal bacteria. The small intestinal tissue was taken for observing histopathological changes (Chiu's score: 0-5 points) after HE staining, and for determining the expression levels of Bcl-2 and Bax proteins using Western blot. The intestinal mucosa was sampled for detecting the apop-tosis (apoptotic index) of lymphocytes by using terminal deoxynucleoitidyl transferase-mediated deoxyuridine triphosphate biotin nick end labeling (TUNEL) assay, and the counts of CD4+ and CD8+T cells using flow cytometry. The contents of IL-4 in the small intestine and that of secretory IgA (sIgA) in the small intestinal mucus were determined by using ELISA., Results: After modeling, of the 15 rats in each of the 3 groups, 7, 7 and 2 in the model, non-acupoint and EA groups were dead in the first 3 days, with the fatality rate being 46.67% (7/15), 46.67% (7/15) and 13.33% (2/15), respectively (being obviously lower in the EA group than in the former two groups, P <0.05). Compared with the sham operation group, the incidence of intestinal bacterial translocation, apoptotic index, Chiu's score, and Bax expression were significantly increased ( P <0.05), and the percentages of CD4 + and CD8 + T cells, IL-4 and sIgA contents and Bcl-2 expression considerably decreased ( P <0.05) in the model group. In comparison with the model group, modeling-induced increase of incidence of bacterial translocation, apoptotic index and Bax expression, and decrease of percentages of CD4 + and CD8 + T cells, IL-4 and sIgA contents and Bcl-2 expression were reversed ( P <0.05) in the EA group., Conclusion: EA at ST36 can reduce death rate and intestinal bacteria translocation incidence in sepsis rats, which may be related to its functions in regulating the expression of intestinal Bcl-2 and Bax proteins and inhibiting the apoptosis of intestinal mucosal T lymphocytes, thereby protecting the immune barrier function of intestinal mucosa to reduce the intestinal permeability.

This study aims to investigate the potential mechanism of curcumin in mediating interleukin-6(IL-6)/signal transducer and activator of transcription 3(STAT3) signaling pathway to repair intestinal mucosal injury induced by 5-fluorouracil(5-FU) chemotherapy for colon cancer. SD rats were intraperitoneally injected with 60 mg·kg~(-1)·d~(-1) 5-FU for 4 days to establish a model of intestinal mucosal injury. Then the rats were randomly divided into model group(equal volume of normal saline), curcumin low, medium and high dose groups(50, 100, 200 mg·kg~(-1)), and normal SD rats were used as control group(equal volume of normal saline). Each group received gavage administration for 4 consecutive days, and the changes of body weight and feces were recorded every day. After administration, blood was collected from the heart, and jejunum tissues were collected. The levels of serum interleukin-1β(IL-1β) and tumor necrosis factor-α(TNF-α) were detected by ELISA, and at the same time, the concentration of Evans blue(EB) in jejunum was measured. Hematoxylin-eosin(HE) staining was used to observe the pathological state of jejunum, and the length of jejunum villi and the depth of crypt were measured. The positive expression levels of claudin, occludin and ZO-1 were detected by immunohistochemistry. Western blot was used to detect the protein expression of IL-6, p-STAT3, E-cadherin, vimentin and N-cadherin in jejunum tissues. The results showed that, curcumin significantly increased body weight and fecal weight(P&lt;0.05 or P&lt;0.01), decreased fecal score, EB concentration, IL-1β and TNF-α levels(P&lt;0.05 or P&lt;0.01) in rats. In addition, curcumin maintained the integrity of mucosal surface and villi structure of jejunum to a large extent, and reduced pathological changes in a dose-dependent manner. Meanwhile, curcumin could increase the positive expression of occludin, claudin and ZO-1(P&lt;0.05 or P&lt;0.01), repair intestinal barrier function, downregulate the protein expression of IL-6, p-STAT3, vimentin and N-cadherin in jejunum tissues(P&lt;0.05 or P&lt;0.01), and upregulate the protein expression of E-cadherin(P&lt;0.05). Therefore, curcumin could repair the intestinal mucosal injury induced by 5-FU chemotherapy for colon cancer, and the mechanism may be related to the inhibition of IL-6/STAT3 signal and the inhibition of epithelial-mesenchymal transition(EMT) process.

Objective: To investigate the association between adherens junction proteins E-cadherin and β-catenin and tight junction protein claudin-2 and clinical symptoms in patients with diarrhea predominant irritable bowel syndrome (IBS-D). Methods: Cecal biopsy tissues were collected from IBS-D patients ( n =26) according to Rome Ⅲ criterion and healthy controls ( n =26). The duration of symptoms, abdominal pain score and mean weekly bowel movements were recorded. Colorectal dilatation combined with restraint stress were applied to establish visceral hypersensitivity rat model. Abdominal contraction reflex (AWR) was applied to assess the visceral sensitivity in rats. The stool frequency within 1 hour was recorded after establishing the rat model. The expression of E-cadherin、β-catenin and claudin-2 were assessed by Western blot and immunofluorescence microscopy. Intercellular ultrastructure was observed by transmission electron microscopy. Results: Compared with the healthy controls, the protein expression of E-cadherin and β-catenin in cecal epithelium in IBS-D patients were significantly lower ( P =0.015 and P =0.005, respectively), while claudin-2 was significantly higher ( P =0.000). Reduced E-cadherin and β-catenin expression was associated high abdominal pain score ( r =-0.463, P =0.017 and r =-0.407, P =0.039). The lower expression of β-catenin was associated with longer duration of symptoms ( r =-0.458, P =0.019). The protein expression of E-cadherin and ß-catenin in the cecal epithelium of the visceral hypersensitivity rats were significantly lower ( P =0.004 and P =0.003, respectively), while claudin-2 was significantly higher ( P =0.008). Reduced E-cadherin and ß-catenin expression was associated high visceral sensitivity in IBS-D rats ( r =-0.639, P =0.047 and r =-0.888, P =0.001). Conclusions: Intercellular ultrastructure alterations well as cecal β-catenin and E-cadherin protein expression decrease and are associated with high abdominal pain score in IBS-D patients and hypersensitivity rats. β-catenin is further associated with prolonged duration of symptoms in IBS-D patients. The expression of E-cadherin and β-catenin may play a vital role in visceral sensitivity and intestinal barrier dysfunction in IBS-D.

Objective: To investigate the changes and clinical significances of intestinal fatty acid binding protein (I-FABP) and D-lactic acid levels in early intestinal injury of patients with sepsis and septic shock., Methods: A prospective observational study was conducted. Thirty septic patients (septic group) and 30 septic shock patients (septic shock group) were admitted to the intensive care unit (ICU) of General Hospital of Ningxia Medical University from August 2018 to December 2018, and 20 healthy adults were served as healthy control group. Serum samples were collected within 24 hours after ICU admission in septic shock and septic groups, and in healthy control group during physical examination. The serum I-FABP, D-lactic acid, endotoxin, hypersensitive C-reactive protein (hs-CRP), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and lactic acid (Lac) were determined. Gender and age of all subjects, and basic diseases, the main area of infection and acute physiology and chronic health evaluation II (APACHE II) scores within 24 hours after ICU admission of all patients were recorded. At the same time, the survival of the patients was followed up for 28 days. Spearman correlation analysis was used to analyze the correlation between serum I-FABP, D-lactic acid and other parameters. Risk factors of death in patients with sepsis and septic shock were screened by multivariate Logistic regression analysis of bicategorized variables., Results: There was no significant difference in gender or age among the groups, as well as in the proportion of basic diseases, celiac infection or non-celiac infection between the sepsis group and the septic shock group, indicating that the general clinical baseline data among the groups were comparable. Serum levels of I-FABP and D-lactic acid in the sepsis group and the septic shock group were significantly higher than those in the healthy control group [I-FABP (μg/L): 27.46 (22.52, 34.39), 36.95 (29.82, 44.24) vs. 17.93 (14.65, 22.11), D-lactic acid (mg/L): 15.32 (9.84, 38.62), 27.95 (10.01, 47.69) vs. 9.38 (8.81, 14.48), all P < 0.01]. The serum level of I-FABP in the septic shock group was significantly higher than that in the sepsis group (P < 0.05), but the difference in serum D-lactic acid level between the two groups was not statistically significant (P > 0.05). Serum I-FABP level in the celiac infection group (n = 40) was significantly higher than that in the non-celiac infection group [n = 20; μg/L: 34.76 (27.46, 43.90) vs. 25.71 (20.55, 37.77), P < 0.01], but the difference in serum D-lactic acid level was not statistically significant [mg/L: 25.13 (9.83, 40.55) vs. 30.36 (10.17, 50.00), P > 0.05]. There was no significant difference in serum I-FABP or D-lactic acid levels between the survival group (n = 34) and the death group [n = 26; I-FABP (μg/L): 33.39 (25.20, 39.50) vs. 29.26 (22.50, 43.81), D-lactic acid (mg/L): 14.83 (9.71, 38.45) vs. 33.90 (11.93, 45.34), both P > 0.05]. Correlation analysis between serum I-FABP, D-lactic acid level and endotoxin, inflammatory factors, Lac and APACHE II score in septic and septic shock patients showed that only D-lactic acid was significantly positively correlated with TNF-α and Lac (r values were 0.455 and 0.406, respectively, both P < 0.01), while I-FABP was not correlated with endotoxin, inflammatory factors, Lac or APACHE II score. Multivariable Logistic regression analysis showed the APACHE II score was an independent risk factor to affect the prognosis (death for 28 days) of septic and septic shock patients [odds ratio (OR) = 1.248, 95% confidence interval (95%CI) = 1.091-1.427, P = 0.001], while I-FABP, D-lactic acid, endotoxin, hs-CRP, TNF-α, IL-6, and Lac had no impact on 28-day prognosis of patients., Conclusions: Serum I-FABP and D-lactic acid levels can evaluate early intestinal injury in patients with sepsis and septic shock, but neither of them is related to the prognosis of patients.

As a natural extract from turmeric, curcumin has extensive pharmacological effects, such as anti-tumor, anti-inflammation, anti-oxidative stress, anti-microbial, immunoregulation and so on. In recent years, an increasing number of basic and clinical researches have shown that curcumin takes therapeutic effects on various diseases, such as gastrointestinal diseases, cardiovascular diseases, autoimmune diseases, neuropsychiatric diseases and so on. Many of the pharmacological effects and mechanisms of curcumin are associated with protective effects of intestinal mucosal barrier. It can protect intestinal mucosal barrier through mutiple pathways, including anti-inflammation, anti-oxidative stress, anti-bacterial, anti-apoptosis, regulating intestinal microecology and intestinal immune response and so on. This paper summarizes the protective effects of curcumin on intestinal barrier function and the mechanism, in order to provide new ideas for diagnosis and treatment of intestinal dysfunction.

Objective: To investigate the effects of short chain fatty acid (SCFA) on barrier disruption of human intestinal epithelial cell induced by endotoxin/lipopolysaccharide (LPS) and the related mechanism. Methods: The human intestinal epithelial cell line Caco-2 was used to reproduce monolayer-cells. Cells were divided into control group, LPS group, and SCFA+ LPS group according to the random number table. Cells in control group were only routinely cultured with DMEM medium. Cells in LPS group were cultured with DMEM medium and LPS with final mass concentration of 10 μg/mL. Cells in SCFA+ LPS group were cultured with DMEM medium, LPS and SCFA (consisting of 0.5 mmol/L acetate, 0.01 mmol/L propionate, and 0.01 mmol/L butyrate) with final mass concentration of 10 μg/mL. At post culture hour (PCH) 0, 1, 2, 6, 12, and 24, transepithelial electrical resistance (TER) of cells was determined with an ohmmeter, with sample number of 72. Another portion of cells were divided and treated as above, and then Western blotting was employed to detect the protein expressions of zonula occludens 1 (ZO-1), occludin, and claudin-1 at PCH 24, with sample number of 6. Another portion of cells were divided and treated as above and then immunofluorescence was used to observe cellular morphology and distribution of ZO-1. Data were processed with analysis of variance of factorial design, one-way analysis of variance, least-significant difference test, and Bonferroni correction. Results: (1) Compared with that in control group, TER of cells in LPS group was significantly reduced from PCH 1 to 24 ( P <0.01), while TER of cells in SCFA+ LPS group showed no obvious change ( P >0.05). TER of cells in SCFA+ LPS group was significantly higher than that in LPS group from PCH 1 to 24 ( P <0.01). (2) Compared with the protein expressions of ZO-1, occludin, and claudin-1 of cells in control group (1.25±0.10, 1.17±0.04, and 1.24±0.20), those of cells in LPS group (0.74±0.23, 0.76±0.11, and 0.77±0.11) at PCH 24 were significantly decreased ( P <0.05), while those of cells in SCFA+ LPS group (1.23±0.46, 1.05±0.09, and 1.01±0.13) showed no significant differences ( P >0.05). Protein expressions of occludin and claudin-1 of cells in SCFA+ LPS group were significantly higher than those in LPS group at PCH 24 ( P <0.05). Protein expression of ZO-1 of cells in SCFA+ LPS group was higher than that in LPS group at PCH 24 with no significant difference ( P >0.05). (3) At PCH 24, cells in control group were compact in arrangement with pebble-like appearance, and ZO-1 was distributed smoothly and continuously along the cell membrane. In LPS group, cells were sparse in arrangement with change in appearance, and ZO-1 was distributed uncontinuously along the cell membrane with curls and breaks. In SCFA+ LPS group, the appearance of cells and distribution of ZO-1 were remarkably ameliorated compared with those in LPS group. Conclusions: SCFA can alleviate the barrier disruption of human intestinal epithelial cell induced by LPS through interdicting the abnormal distribution of ZO-1 and decrease of TER and tight junction proteins' expressions.

Objective: To evaluate the changes of macrophages and expression of Rac1 in the inflammatory site of Crohn's disease, and to investigate the effects of 6-thioguanine (6-TG) and peptidoglycan on apoptosis of human peripheral blood monocyte-macrophage by regulating Rac1 signaling pathway. Methods: Ten patients with Crohn's disease and eight healthy controls diagnosed were enrolled at Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital from January 2013 to January 2014. The number of macrophages, apoptosis and expression of Rac1 in the inflammation sites and non-inflammation sites of intestinal mucosa were detected in both patients and controls. Peripheral blood mononuclear cells (PBMCs) were sorted by CD 14 immunomagnetic beads. The apoptosis of monocytes, expression of Rac1 and related apoptosis signaling molecules were detected in patients treated with peptidoglycan, 6-TG and Rac1 inhibitor NSC23766 and another 15 healthy donors. Results: The number of macrophages and apoptotic cells significantly increased in the inflammatory group of Crohn's disease patients compared with the non-inflammatory group. The expression of PAK1, downstream molecular of Rac1 signaling pathway of macrophages was also significantly higher in the inflammatory group of Crohn's disease patients than that in healthy controls and non-inflammatory group. Compared with control group, anti-apoptotic signals (NF-κB, Bcl-xL and STAT-3) in PBMCs increased in the peptidoglycan group, while slightly decreased in 6-TG group. 6-TG and NSC23766 significantly promoted peptidoglycan-related anti-apoptosis [peptidoglycan group (8.6±3.7)%, peptidoglycan+ 6-TG group (42.0±2.7)%, peptidoglycan+ NSC23766 group (58.5±6.9)%, P< 0.05]. Conclusions: Peptidoglycan plays a role in the pathogenesis of Crohn's disease by recruiting macrophages. However, 6-TG inhibits peptidoglycan-induced activation of Rac1 signaling pathway leading to macrophage apoptosis.

Objective To analyze the therapeutic effect of green tea polyphenols (GTP) in mice with colitis induced by TNBS and its possible mechanism. Methods Colitis was induced by TNBS in BALB/C mice. The mice were randomly divided into GTP group (n=10) and TNBS model group (n=10). Mice in the GTP group were given GTP [0.2 mL at a dose level of 100 mg/(kg.d)] by oral gavage, and mice in the model group were given normal saline [0.2 ml/d] by gavage. Four weeks later, the mice were sacrificed. Disease activity index (DAI) and inflammatory score were evaluated by HE staining. The levels of interleukin 10 (IL-10), IL-6 and tumor necrosis factor α (TNF-α) were detected by ELISA. The expressions and localization of ZO-1 and claudin-1 were identified with immunofluorescence technique. Western blot analysis was performed to detect the expressions of ZO-1, claudin-1, p-JAK2 and p-STAT3 proteins. Results GTP decreased the DAI and inflammatory score, and reduced the levels of TNF-α and IL-6 in TNBS-induced colitis mice at three and four weeks after the administration. Meanwhile, the levels of ZO-1 and claudin-1 increased in the mice of GTP group when compared with those in model group. Western blot analysis showed that GTP down-regulated the JAK2/STAT3 signaling pathway in the intestinal mucosa. Conclusion GTP has a significant therapeutic effect on TNBS-induced colitis through down-regulating the JAK2/STAT3 signaling pathway.

Objective: To study the effect of Bifidobacterium on the expression of β-defensin-2 (BD-2) in intestinal tissue of neonatal rats with necrotizing enterocolitis (NEC)., Methods: A total of 40 rats were randomly divided into four groups: normal control, Bifidobacterium control, NEC model, and Bifidobacterium treatment, with 10 rats in each group. A rat model of NEC was induced by hypoxia, cold stimulation, and artificial feeding. The rats in the Bifidobacterium control and Bifidobacterium treatment groups were given Bifidobacterium via the gastric tube after cold stimulation once a day for three consecutive days. The morphological changes of the terminal ileum were observed under a light microscope and the intestinal injury score was determined. Immunohistochemistry and qRT-PCR were used to measure the protein and mRNA expression of BD-2 in the ileal mucosal tissue., Results: The NEC model group had a significantly higher intestinal injury score than the normal control, Bifidobacterium control, and Bifidobacterium treatment groups (P<0.05). The Bifidobacterium treatment group had a significantly higher intestinal injury score than the normal control and Bifidobacterium control groups (P<0.05). The mRNA and protein expression of BD-2 in the normal control group was significantly lower than in the Bifidobacterium control, NEC model, and Bifidobacterium treatment groups (P<0.05). The Bifidobacterium control group had significantly higher mRNA and protein expression of BD-2 than the NEC model and Bifidobacterium treatment groups (P<0.05). The Bifidobacterium treatment group had significantly higher mRNA and protein expression of BD-2 than the NEC model group (P<0.05)., Conclusions: Bifidobacterium can induce the expression of BD-2 in intestinal tissue of rats and reduce inflammatory response by increasing the expression of BD-2. This provides a protective effect on neonatal rats with NEC.

Objective: To investigate the effects of Toll-like receptor blockers TLR2-Ab and TLR4-Ab on the tight junction protein ZO-1 in intestinal epithelial cells in mice, as well as their effects on nuclear factor-kappa B (NF-κB) and tumor necrosis factor-α (TNF-α)., Methods: A total of 32 BALB/C mice were divided into control group, model group, TLR4 treatment group, and TLR2 treatment group, with 8 mice in each group. A mouse model of endotoxemia was established by intraperitoneal injection of lipopolysaccharide. The mice in the TLR4 treatment group and the TLR2 treatment group were given intraperitoneal injection of TLR4 antibody and TLR2 antibody (10 μg each mouse), respectively, and those in the control group were given normal saline. The distal small intestinal tissue was collected, and RT-PCR and immunohistochemistry were used to measure the mRNA and protein expression of ZO-1, NF-κBp65, and TNF-α., Results: Compared with the control group, the model group had significantly lower mRNA and protein expression of ZO-1 and significantly higher mRNA expression of NF-κBp65 and TNF-α (P<0.05). Compared with the model group, the TLR4 treatment group and the TLR2 treatment group had significantly higher mRNA and protein expression of ZO-1 and significantly lower mRNA and protein expression of NF-κBp65 and TNF-α (P<0.05). There were no significant differences in the mRNA and protein expression of ZO-1, NF-κBp65, and TNF-α between the TLR4 treatment group and the TLR2 treatment group (P>0.05)., Conclusions: Anti-TLR2 and anti-TLR4 monoclonal antibodies can reduce the activation of nuclear transcription factors, inhibit the secretion of inflammatory factors, and protect tight junction protein, which is expected to provide new ideas for the treatment of enterogenous infectious diseases.

To study the intestinal absorptive characteristics of the ethanol extracts from Gandou decoction(GDD), everted intestinal sac models were used. The six representative ingredients (berberine hydrochloride, quercetin, kaempferide, rhein, chrysophanol, and aloe emodin) of GDD, were selected as the experimental targets to investigate the absorptive characteristics of various ingredients in different intestinal sections. The results showed that all six ingredients from GDD were detected in the intestinal sac, three active ingredients (berberine hydrochloride, quercetin, kaempferide) in high, medium and low doses had linear absorption properties in the small intestine segment, consistent with zero-order absorption rate; in addition, the absorption rate constant (Ka) of three components in jejunum and ileum were increased with the increase of the concentration of GDD (P<0.05), consistent with passive absorption. However, the Ka of rhein in jejunum and ileum showed little difference with the increase of dosage, suggesting a possibility of active transport mechanism. Chrysophanol and aloe-emodin were poorly absorbed in the two segments, which had not been detected in the previous time. The results suggested that the components of GDD were selectively absorbed in the intestinal sac, and the absorption characteristic of the ingredients were not exactly similar., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

Objective: To investigate the change in the expression of tight junction protein ZO-1 in intestinal epithelial cells (Caco-2 cells) and the protective effect of eicosapentaenoic acid (EPA) after adherent-invasive Escherichia coli (E.coli) LF82 infection., Methods: The Caco-2 cell line was used to establish an in vitro model of tight junction of intestinal epithelial cells. Caco-2 cells were divided into EPA treatment groups (0, 25, 50, 100, and 200 μmol/L EPA) and EPA (0, 25, 50, 100, and 200 μmol/L EPA)+E.coli LF82 treatment (0, 6, and 12 hours) groups. A microscope was used to observe the morphological characteristics of the cells. MTT assay was used to determine the cell growth curve. The activity of alkaline phosphatase (ALP) at both sides of the cell membrane was compared to evaluate the Caco-2 cell model. MTT assay and flow cytometry were used to investigate the effects of different concentrations of EPA on the survival rate and apoptosis rate of Caco-2 cells. RT-qPCR was used to measure the mRNA expression of ZO-1 in Caco-2 cells after EPA and/or E.coli LF82 treatment. ELISA was used to measure the change in the level of tumor necrosis factor-α (TNF-α) in culture supernatant., Results: After EPA treatment (25 and 50 μmol/L), the proliferation of Caco-2 cells was induced in a dose-dependent manner. The survival rates of the cells were significantly higher than those in the control group (P<0.05). The EPA treatment (100 and 200 μmol/L) groups had a significant inhibitory effect on the proliferation of Caco-2 cells in a dose-dependent manner. The survival rates of the cells were significantly lower than those in the control group (P<0.05). The EPA treatment (100 and 200 μmol/L) groups had a significant increase in cell apoptosis rate compared with the control group (P<0.05). The 6- and 12-hour E.coli LF82 treatment groups had decreasing mRNA expression of ZO-1 in Caco-2 cells over the time of treatment and had significantly lower mRNA expression of ZO-1 than the untreated group (P<0.05). The Caco-2 cells treated with E.coli LF82 and 25 or 50 μmol/L EPA for 6 or 12 hours showed an increase in the mRNA expression of ZO-1 with the increasing concentration of EPA, as well as significantly higher mRNA expression of ZO-1 than the Caco-2 cells treated with E.coli LF82 alone (P<0.05). The Caco-2 cells treated with E.coli LF82 alone for 6 or 12 hours had increasing secretion of TNF-α over the time of treatment and had significantly higher secretion than the untreated Caco-2 cells (P<0.05). The Caco-2 cells treated with E.coli LF82 and 25 or 50 μmol/L EPA for 6 or 12 hours showed a reduction in the secretion of TNF-α with the increasing concentration of EPA and had significantly lower secretion than the Caco-2 cells treated with E.coli LF82 alone (P<0.05)., Conclusions: EPA can effectively prevent the destruction of tight junction of intestinal epithelial cells induced by E.coli LF82 infection and inhibit the secretion of inflammatory factors. Therefore, it has a certain protective effect on intestinal mucosal barrier.

Objective: To study the expression status and clinical significance of PTEN and NDRG1 in colorectal carcinoma. Methods: Tissue samples of 91 colorectal cancers, 30 colorectal adenomas and 21 colorectal normal mucosa tissues were collected. Postoperative specimens were examined by immunohistochemistry for PTEN and NDRG1 expression. The expression of PTEN and NDRG1 was correlated with clinicopathological feature. Results: The expression of PTEN and NDRG1 in the studied cases was detected in 55.0%(50/91) and 76.9%(70/91), respectively. Their expression was significantly different from that of colorectal adenomas and normal colorectal mucosa tissues( P <0.05). Decreased expression of PTEN and over expression of NDRG1 were significantly related to the lymph node metastasis ( P <0.05). The expression of PTEN was negatively related to that of NDRG1 in colorectal carcinoma( r s '=-0.251, P =0.016). The patients with negative expression of PTEN showed a lower disease free survival and overall survival( P <0.05). Conclusions: Loss of expression of PTEN protein may be an important molecular marker in predicting the occurrence and PTEN may be useful as a prognostic marker of colorectal carcinoma. NDRG1 plays a role in the development of colorectal carcinoma, although not a prognostic indicator.The ancillary study with combined detection of PTEN and NDRG1 may be useful in difficult cases.

Objective: To investigate the protective effect of Saccharomyces boulardii against intestinal mucosal barrier injury in rats with nonalcoholic fatty liver disease (NAFLD). Methods: A total of 36 healthy male Sprague-Dawley rats with a mean body weight of 180±20 g were randomly divided into control group, model group, and treatment group, with 12 rats in each group, after adaptive feeding for 1 week. The rats in the control group were given basic feed, and those in the model group and treatment group were given high-fat feed. After 12 weeks of feeding, the treatment group was given Saccharomyces boulardii (75×10 8 CFU/kg/d) by gavage, and those in the control group and model group were given isotonic saline by gavage. At the 20th week, blood samples were taken from the abdominal aorta to measure the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), intestinal fatty acid binding protein (IFABP), tumor necrosis factor-α (TNF-α), and endotoxins. The liver pathological changes, intestinal histopathological changes, and expression of occludin in the intestinal mucosa were observed. Fecal samples were collected to measure the changes in Escherichia coli and Bacteroides. A one-way analysis of variance and the SNK test were used for comparison between multiple groups, and the rank sum test was used as the non-parametric test. Results: Compared with the control group, the model group had significantly higher body weight, liver mass, and liver index ( P < 0.05), and compared with the model group, the treatment group had significant reductions in body weight, liver mass, and liver index ( P < 0.05). The model group had significant increases in TG, ALT, and AST compared with the control group ( P < 0.05), the treatment group had a significant reduction in AST compared with the model group ( P < 0.05), and the treatment group had slight reductions in TG and ALT compared with the model group ( P > 0.05). Compared with the control group, the model group had significant increases in the levels of endotoxin, TNF-α, and IFABP ( P < 0.05), and the treatment group had significant reductions in the levels of endotoxin, TNF-α, and IFABP ( P < 0.05). Liver tissue staining showed that the model group had significantly increased hepatocyte steatosis compared with the control group ( P < 0.05), and that the treatment group had significantly reduced hepatocyte steatosis compared with the model group ( P < 0.05). The intestinal villi in the control group had ordered arrangement and a complete structure; in the model group, the intestinal villi were shortened with local shedding and a lack of ordered arrangement; compared with the model group, the treatment group had mild edema and ordered arrangements of the intestinal villi. The model group had a significantly reduced level of occludin protein compared with the control group ( P < 0.05), and the treatment group had a slight increase compared with the model group. The model group had a significantly increased number of Escherichia coli and a significantly reduced number of Bacteroides compared with the control group ( P < 0.05), and the treatment group had a significantly reduced number of Escherichia coli and a significantly increased number of Bacteroides compared with the model group ( P < 0.05). Conclusion: High-fat diet can successfully induce NAFLD in rats, and intervention with Saccharomyces boulardii can reduce body weight and improve hepatocyte steatosis. Saccharomyces boulardii can reduce endotoxemia in NAFLD rats and thus alleviate inflammatory response. Saccharomyces boulardii can also adjust the proportion of Escherichia coli and Bacteroides in the intestine of NAFLD rats.

Objective: To detect the expressions of IL-17, IL-23, IL-22 and IL-11 in the intestinal mucosa of patients with ulcerative colitis (UC) and analyze their prognostic values., Methods: Forty patients with active UC, 15 with UC in remission and 15 healthy subjects were examined for the expressions and distribution of IL-17, IL-23, IL-22, and IL-11 in the colorectal mucosausing immunohistochemistry. We further collected the data from 40 patients with routine therapy and regular follow-up and compared the expressions of those cytokines according to the condition of mucosal healing., Results: The expressions of cytokines in patients with active UC were significantly higher than those in patients with remittent UC and healthy control subjects (IL-17: 0.0727∓0.0037 vs 0.0354∓0.0243 vs 0.0330∓0.0045; IL-23: 0.1407∓0.0068 vs 0.0865∓0.0051 vs 0.0442∓0.0137; IL-22: 0.0522∓0.0045 vs 0.0259∓0.0063 vs 0.0115∓0.0061; IL-11: 0.0479∓0.0022 vs 0.0365∓0.0024 vs 0.0232∓0.0009, P<0.05). The expression levels of IL-17, IL-23, and IL-22 increased significantly with the increase of the disease activity (IL-17: 0.0545∓0.0072 vs 0.0786∓ 0.0051 vs 0.0847∓0.0197; IL-23: 0.1112∓0.0046 vs 0.1480∓0.0089 vs 0.1644∓0.0190; IL-22: 0.0307∓0.0063 vs 0.0548∓ 0.0071 vs 0.0719∓0.0056, P<0.05). In patients with active UC, the expression levels of the 4 cytokines in the intestinal mucosa were positively correlated with the endoscopic activity grade (P<0.05), and IL-17 and IL-22 expression levels were also positively correlated with the histological grade (P<0.05). All the 4 cytokines were positively intercorrelated. The patients with low IL-17 expression (25.00%) showed a significantly lower rate of poor mucosal healing than those with high IL-17 expressions (25% vs 67%, P<0.05)., Conclusion: The cytokines IL-17, IL-23, IL-22, and IL-11 all participate in the pathogenesis of UC and may serve as indicators for evaluating the inflammatory activity. The expression level of IL-17 can be a valuable indicator for predicting mucosal healing in UC patients after a short-term treatment.

Objective: To observe the effect of vasoactive intestinal peptide (VIP) on the metabolism of intestinal fluid and cyclic AMP protein kinase A signaling pathway (cAMP-PKA) and water channel protein 3 (AQP3) in rats with constipation, and to explore the mechanism of VIP in the treatment of constipation.
 Methods: A total of 45 healthy adult rats were randomly divided into a control group, a model group, a model +VIP group. After 4 weeks of VIP treatment, the first black stool time were examined with the ink gastric method; the water content in feces was calculated; the morphological changes in colonic tissues were observed by HE staining. The expression of VIP and AQP3 protein levels in colon tissues were detected by Western blot; and the cAMP, PKA, AQP3 mRNA expression levels were detected by quantitative real time polymerase chain reaction (qPCR). 
 Results: Compared with the control group, the first black stool time was prolonged, the water content of fecal decreased significantly (both P<0.01); part of the colon mucosa epithelial cells were destructed; the goblet cell volume decreased and quantity was reduced; the contents of AQP3 and VIP in colon tissues were significantly decreased, and the cAMP, PKA and AQP3 mRNA levels were decreased in the model group (all P<0.05). Compared with the model group, the first black stool time in the model +VIP group was shortened, the fecal water content increased significantly (both P<0.05); the mucosal epithelium integrity improved, the number of goblet cells increased; the content of AQP3 and VIP in colon tissues was increased, and the cAMP, PKA, and AQP3 mRNA levels were elevated (all P<0.05).
 Conclusion: Intravenous injection of VIP can regulate intestinal fluid metabolism and improve the symptoms of constipation in rats, which might be related to the regulation of VIP-cAMP-PKA-AQP3 signaling pathway.

Objective: To investigate the effect of respiratory syncytial virus (RSV)-related pulmonary infection on endogenous metabolites in large intestinal mucosa in BALB/c mice using metabolomics technology based on gas chromatography-mass spectrometry (GC-MS)., Methods: Mice were randomly divided into a control group and a RSV pneumonia model group (n=16 each). The mouse model of RSV pneumonia was established using intranasal RSV infection (100×TCID 50 , 50 μL/mouse, once a day). After 7 days of intranasal RSV infection, the mice were sacrificed and GC-MS was used to identify endogenous metabolites and measure the changes in their relative content in colon tissue. SMCA-P12.0 software was used to perform principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) for endogenous metabolites in colon tissue. The differentially expressed metabolites in colon tissue were imported into the metabolic pathway platform Metaboanalyst to analyze related metabolic pathways., Results: PCA and OPLS-DA showed significant differences between the control and RSV pneumonia model groups. A total of 32 metabolites were identified in the colon tissue of the mice with RSV pneumonia. The RSV pneumonia model group had significant increases in the content of leucine, isoleucine, glycine, alanine, arachidonic acid, and lactic acid, which were related to the valine, leucine, isoleucine, arachidonic acid, and pyruvic acid metabolic pathways., Conclusions: RSV pneumonia might cause metabolic disorders in the large intestinal tissue in mice.

Objective: To characterize the metabolic " fingerprint" of fecal extracts for diagnosis of early-stage colorectal cancer(CRC)using proton nuclear magnetic resonance spectroscopy( 1 H-NMR)-based metabolomics coupled with pattern recognition. Methods: From January 2014 to December 2014, we collected fecal samples at the Second Affiliated Hospital of Shantou University Medical College, from 25 patients with colorectal adenomas(CR-Ad), 20 with stage Ⅰ/Ⅱ CRC, and 32 healthy controls(HCs). The patients were diagnosed by histopathology. No subjects had any complicating diseases. HCs showed no abnormalities from blood tests, endoscopic examination, diagnostic imaging, and/or medical interviews. We excluded participants who used antibiotics, NSAIDS, statins, or probiotics within two months of study participation, and any patients who underwent chemotherapy or radiation treatments prior to surgery. We used orthogonal partial least-squares-discriminant analysis(OPLS-DA)for pattern recognition(dimension reduction)on 1 H-NMR processed data( 1 H frequency of 400.13 MHz), to find metabolic differences among CR-Ad, carcinoma and HC fecal samples; and receiver operating characteristic(ROC)analysis to determine the diagnostic value of the fecal metabolic biomarkers. Results: Fecal samples were collected from 20 patients with Stage Ⅰ/Ⅱ CRC(11 M, 9 F, median age(52±13)years), 25 with CR-Ad(14 M, 11 F, median age(53 ± 11)years)and 32 HCs(15 M, 17 F, median age(53 ± 14)years). OPLS-DA clearly distinguished CR-Ad and stage Ⅰ/Ⅱ CRC from HC samples, based on their metabolomic profiles. Relative signal intensities in HCs were significantly lower than in the cancer patients for butyrate(HC: 23.0±6.0; CR-Ad: 18.0±5.0; CRC: 14.0±6.0; Z =-2.07, P =0.008), acetate(HC: 45.0±11.0; CR-Ad: 31.0±11.0; CRC: 24.0±8.0; Z =- 2.32, P =0.011), propionate(HC: 26.0 ± 7.0; CR-Ad: 22.0 ± 6.0; CRC: 19.0 ± 5.0; Z =- 2.43, P =0.032), glucose(HC: 37.0±7.0; CR-Ad: 31.0±7.0; CRC: 26.0±8.0; Z =-2.07, P =0.044)and glutamine(HC: 4.5±2.0; CR-Ad: 4.9 ± 1.0; CRC: 5.4 ± 1.0; Z =2.21, P =0.044). However, relative signal intensities in HCs were significantly higher than in patients for lactate(HC: 4.8±1.0; CR-Ad: 6.9±2.0; CRC: 4.8± 1.0; Z =2.02, P = 0.038), glutamate(HC: 3.2 ± 2.0; CR-Ad: 4.9 ± 1.0; CRC: 3.2 ± 2.0; Z =2.21, P =0.044)and succinate(HC: 12.0±2.0; CR-Ad: 15.0±3.0; CRC: 12.0± 2.0; Z =2.25, P =0.011). Among the potential biomarkers, acetate at 1.92 ppm, and succinate at 2.41 ppm displayed relatively high area under ROC, with sensitivity and specificity both >90%, to distinguish early-stage CRC patients from HCs. Conclusion: Fecal metabolic profiles distinguish of HCs from patients with CRC patients, even in the early stages(stage Ⅰ/Ⅱ), highlighting the potential of NMR-based fecal metabolomic fingerprinting as tools for early CRC diagnosis.

Objective: The objective of the study was to study the effects of Lactobacillus plantarum and Lactobacillus casei on the changes in composition and quantity of microbial populations and the concentrations of short chain fatty acids in the gut digesta of piglets before and after weaning, to explore the mechanisms of the tested two strains to relieve weaning stress., Methods: Fifteen litters of piglets (Duroc×Yorkshire×Landrace) at the age of 7 days were randomly allocated to 3 groups (5 each), including the control group with an oral administration of saline, LP group with L. plantarum and and LC group, with L. casei. On day 21, 24 and 35, the piglets were slaughtered, and the ileum and colon digesta were analyzed for microbial populations and short chain fatty acids., Results: In the ileum and colon, the test strains significantly increased the microbial diversity (P<0.05), promoted the growth of Lactobacilli spp. and Bifidobacteria spp. after 2 weeks of post-weaning. The two test strains increased the concentration of acetate, propionate, butyrate and total short chain fatty acids both in ileum and colon before weaning, and the concentration of acetate, total short chain fatty acids after weaning. Correlation analysis showed that the decreased diarrhea rate before weaning in the LP and LC groups was significant associated with the increased short chain fatty acids concentration and total bacteria of ileum and colon, the increased height of the ileum villi. The improved average daily gain presented a correlation with the increased concentration of acetate and total short chain fatty acids of colon., Conclusion: The findings imply that the tested strains are contribute to increase the microbial diversity, the quantities of beneficial bacteria and the production of short chain fatty acids in the gut intestinal tract of weaning piglets.

Objective To study the effect of intestinal dysbacteriosis on mouse intestinal intraepithelial T lymphocytes (iIELs). Methods The intestinal dysbacteriosis was induced in mice by oral administration of ceftriaxone sodium. The iIELs were digested with ethylene diaminetetraacetic acid (EDTA) and DL-dithiothreitol (DTT). The phenotype of iIELs and the proportions of subsets of T cells were detected by flow cytometry; the concentrations of cytokines (IL-2, IL-6, IFN-γ) in the intestine were examined by ELISA; the intestinal bacteria were analyzed with selective medium and PCR. Results Compared with the control group, intestinal commensal bacteria in mice were significantly reduced after the administration of ceftriaxone sodium, but fungi and yeasts increased. The proportions of T cell subgroups in ilELs changed, in which the proportion of TCR γδ(+)T cells significantly increased, and the activated CD3(+)T, CD8(+)T and TCR γδ(+)T cells increased. The concentrations of IL-2, IL-6 and IFN-γ were significantly raised in the intestine. Conclusion The dysbacteriosis results in the decrease of commensal bacteria, the increase of the fungus, the damage of microbial barrier, the more activated T cells in ilELs and the promotion of proinflammatory cytokine secretion in the gut. This is probably one of the reasons for inflammatory bowel disease caused by dysbacteriosis.

Based on high throughput sequencing and PCR detection technology, this study has found out that intestinal microbial diversity was impaired and the quantities of two main bacteria flora (Bacteroidetes and Clostridium) were significantly reduced in patients with diarrhea-predominant irritable bowel syndrome (D-IBS). Meanwhile mucosal expression of toll-like receptor (TLR) 2 and TLR4 were significantly enhanced, which was inversely correlated with the reduction of Bacteroidetes and Clostridium. Thus, it suggests that D-IBS may be associated with TLR signal transduction triggered by the intestinal dysbacteriosis.

To study the in vivo intestinal absorption kinetics of phloridzin in rats. The absorption of phloridzin in the small intestines and colon of rats was investigated using an in vivo single-pass perfusion method and the drug concentration was measured by HPLC. The effects on intestinal absorption of different drug concentration and P-glycoprotein (P-gp) inhibitor were conducted. The results showed that the phloridzin could be absorbed in whole intestine, but more fully in the jejunum and colon segment,poorly absorbed in the duodenum and ileum. The absorption rate constant (Ka) and the apparent absorption coefficient（Papp）of phloridzin decreased following the sequence of jejunum> colon > duodenum > ileum. Absorption parameters of phloridzin had no significant difference at different concentration (5.14, 10.28, 20.56 mg•L⁻¹) . The saturate phenomena was not observed under the test range of drug concentration, and the absorption mechanism may be the passive diffusion transport.There had a significant difference in Ka and Papp values between P-gp inhibitor and no P-gp inhibitor groups. Phloridzin may be the substrate of P-gp., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)