Search

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< 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< 0. 001), while the levels of 5-HT,SCFAs, occludin, claudin-1, and ZO-1 were significantly decreased(P< 0. 01), indicating impaired colonic barrier function;spontaneous alternation accuracy was significantly decreased(P<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<0. 01);Sobs index, Shannon index, and Chao index were increased; LPS was significantly decreased(P<0. 01), while the levels of 5-HT,SCFAs, occludin, claudin-1, and ZO-1 were significantly increased(P< 0. 05), indicating improved colonic barrier function;spontaneous alternation accuracy was increased(P<0. 001). In conclusion, Sijunzi Decoction has the effect of improving intestinal barrier in diabetic 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 " gut-liver axis". 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.

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 explore the effects of D-galactose (D-gal) on barrier function of murine TM4 sertoli cells and its mechanism. Methods TM4 cells were divided into control group and 25, 50, 100, 150, 200, 250 mmol/L D-gal stimulation group. The viability of TM4 cells was determined by MTT assay. The protein expression levels of tight junction-related proteins including zonula occluden-1 (ZO-1) and occludin, adheren junction-related proteins including neural cadherin (N-cadherin), epithelial cadherin (E-cadherin) and β-catenin, gap junction-related protein connexin43 (CX43) and cytoskeleton-related protein vimentin, and MAPK signaling pathway-related proteins ERK1/2, phosphorylated ERK1/2 (p-ERK1/2), JNK, phosphorylated JNK (p-JNK), p38MAPK and phosphorylated p38MAPK (p-p38MAPK) were detected by Western blot analysis. Results Compared with the control group, the viability of TM4 cells significantly decreased when the concentration of D-gal was more than 50 mmol/L. In addition, the protein expression levels of ZO-1, occludin, N-cadherin, E-cadherin and β-catenin were significantly down-regulated in D-gal-treated group, while the protein expression levels of p-p38MAPK were significantly up-regulated. However, there were no differences in the protein expression levels of CX43, vimentin, p-ERK, ERK1/2, p-JNK and JNK between the control group and D-gal-treated groups. Conclusion D-gal can disrupt tight junction and adheren junction of TM4 cells via the activation of p38MAPK signaling pathway.

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.

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 observe the effect of NaHS on lipopolysaccharide (LPS)-induced injury of A549 lung cancer cells and explore the possible mechanisms., Methods: A549 cells were divided into 4 groups: control group, 10 μg/mL LPS treated group, 10 μmol/L NaHS treated group and the group treated with 10 μg/mL LPS plus 10 μmol/L NaHS. After treatment for 24 hours, C-reactive protein (CRP) content in culture solution was measured by ELISA, and the cell viability was detected by MTT assay and lactate dehydrogenase (LDH) assay. Transepithelial electrical resistance (TER) was evaluated by EVOM resistance meter, and the expression and distribution of zonula occludens-1 (ZO-1) protein was examined by immunofluorescence cytochemistry., Results: There were no significant differences in CRP content, TER, cell viability, the expression and distribution of ZO-1 between the control group and the NaHS group. Compared with the control group, CRP content distinctly increased, TER, cell viability and ZO-1 expression markedly decreased, and ZO-1 distribution was disrupted in the LPS group. Compared with the LPS group, CRP level was distinctly reduced, TER, cell viability and ZO-1 expression were raised, and the disrupted ZO-1 distribution was partly reversed in the LPS plus NaHS treated group., Conclusion: NaHS can inhibit A549 cell injury induced by LPS via increasing cell viability, TER and the expression of ZO-1 as well as decreasing CRP level.

Objective: To investigate the methylation status of zonula occludens-1 (ZO-1) gene promoter and its clinical significance in children with stage IV non-Hodgkin lymphoma (NHL) and to provide a basis for further etiological study and early diagnosis of this disease., Methods: Fifty-five children with a confirmed diagnosis of stage IV NHL (40 cases of T-NHL and 15 cases of B-NHL) were selected as the case group, and 20 children with diseases other than hematologic malignancies were selected as the control group. Bone marrow samples were collected from these subjects. Methylation-specific PCR (MS-PCR) was applied to evaluate the methylation status of ZO-1 gene promoter, and the integrated optical density (IOD) was determined. RT-PCR was used to measure the mRNA expression of ZO-1., Results: MS-PCR showed that the methylated bands of ZO-1 gene promoter were found in 39 (70.9%) of 55 patients in the case group before treatment, while no ZO-1 gene promoter methylation was detected in the control group. With close tracking of 47 cases in the study group, consisting of 32 cases of T-NHL and 15 cases of B-NHL, the rates of ZO-1 gene promoter methylation prior to treatment were 72% and 67%, respectively, (P>0.572). The cases of T-NHL and B-NHL showed no significant changes in methylation rate in the early and middle phases of chemotherapy (P>0.05), but they showed significant changes in methylation rate in the late phase of chemotherapy (P<0.05). RT-PCR showed that the NHL cases carrying methylated ZO-1 gene had no mRNA expression of ZO-1, while all children in the control group had mRNA expression of ZO-1. There was no linear relationship between the total number of peripheral blood leukocytes and ZO-1 gene IOD (r=0.093, P=0.575); a positive correlation was found between the number of malignant cells in bone marrow and ZO-1 gene IOD (r=0.669, P<0.001)., Conclusions: ZO-1 gene shows a hypermethylation status in children with NHL, and the methylation level is positively correlated with the number of malignant cells in bone marrow. ZO-1 may be used as a novel molecular marker in early diagnosis, outcome assessment, prognostic evaluation, and detection of minimal residual disease.

Objective: To study the expression of tight junction factors in human placental tissues derived from assisted reproductive technology (ART) and natural pregnancy and its role in placental barrier., Methods: Ten placental samples were collected from the women who had undergone ART treatment and 11 placenta were collected from control group. Transmission electron microscope (TEM) examination was utilized to detect the morphology of placental tight junctions. The mRNA of claudin (CLDN) 1, CLDN4, CLDN5, CLDN8, zonula occudens (ZO) 1 was detected by real-time PCR and the protein of CLDN4, CLDN8 and occludin (OCLN) were measured by western blot., Results: TEM microscopy results showed that placenta samples derived both ART and control placenta had normal microscopic histological features of tight junctions, localized in the apical part of the syncytium and also between the cell-cell contacts of fetal blood vessel endothelial. The expression level of CLDN4 mRNA were 0.87 ± 0.17 in ART group and 1.18 ± 0.30 in control group, respectively. The expression level of CLDN8 mRNA were 3.25 ± 2.32 in ART group and 1.08 ± 0.41 in control group, respectively. The mRNA level of CLDN4 and CLDN8 were significantly differentially expressed in ART derived placenta when compared with control groups. The expression level of CLDN1, CLDN5, OCLN and ZO1 mRNA were 0.49 ± 0.44, 0.80 ± 0.20, 0.92 ± 0.18 in ART group and 1.09 ± 0.82, 1.21 ± 0.78, 0.80 ± 0.27 in control group, respectively, in which there were no significant differences between two groups. Western Blot analysis showed the protein levels of tight junctions CLDN4, CLDN8 and OCLN did not differ between groups., Conclusions: Tight junction factors were expressed in human placental tissues. Tight junction derived from ATR platenta might have mild dysfunction.

Objective: To observe the effect of 25-hydroxyvitamin D3 on the permeability and ZO-1 expression in normal human airway epithelial cells., Methods: MTT assay was used to assess the viability of human airway epithelial cell line 16HBE following a 24-hour exposure to different concentrations of 25-hydroxy vitamin D3, and the transepithelial electrical resistance (TER) of the cell monolayer was measured using a Millicell-ERS voltohmmeter. Real-time quantitative RT-PCR was employed to determine the changes of ZO-1 mRNA expression in the cells following the exposures., Results: Exposure to 25-hydroxyvitamin D3 resulted in significantly increased permeability of 16HBE cells, but the exspression of ZO-1 showed no obvious changes. 25-hydroxyvitamin D3 at 4×10(-9) mol/L showed the strongest effect in increasing the permeability of cell monolayer., Conclusion: 25-hydroxyvitamin D3 increases the permeability of normal bronchial airway epithelial cell monolayer in vitro, but this effect is not mediated by upregulation of ZO-1 expression.

It is hard to discriminate myelodysplastic syndrome(MDS) from many benign hematological diseases. To identify the methylation status of zo-1 gene in MDS, the methylation specific PCR (MS-PCR) and reverse transcription-PCR (RT-PCR) were applied to detect the MDS cell line MUTZ-1, bone marrow of a healthy donor and an aplastic anemia patient. MS-PCR was also employed to detect the bone marrow of 72 patients with benign hematological diseases, 35 MDS-RA patients, and 20 MDS-like patients. The results showed that MDS cell line MUTZ-1 displayed complete methylation of zo-1 promoter without mRNA expression. Inversely, a patient with benign hematological disease and a donor with normal bone marrow showed complete unmethylation of this gene with unaffected mRNA expression. No zo-1 promoter methylation was detected in patients with benign hematological diseases, while aberrant hypermethylation of zo-1 gene promoter were found in 48.6% (18/37) of MDS-RA patients. The positive rate of zo-1 methylation in MDS-RA patients was higher than that in patients with benign hematological diseases (p < 0.05). Seven suspected MDS patients manifested hypermethylation status of zo-1 gene (7/20), 2 were followed up for 1 year and transformed into MDS. It is concluded that relatively high hypermethylation rate of zo-1 promoter is observed in MDS-RA, and no methylation in patients with benign hematological diseases. Therefore, zo-1 gene hypermethylation may be served as a useful epigenetic marker in the differential diagnosis for MDS.