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Background: Pleomorphic adenoma (PA) is a benign tumor, with a high recurrence rate. This study aimed to compare the Mucin-2 (MUC2) expression in primary and recurrent cases of PA in tertiary care hospitals of Peshawar. Methods: In this study, there were 60 PA cases, 51 being primary lesions and 9 recurrent lesions. Formalin-fixed and paraffin-embedded (FFPE) blocks of the two groups were examined for the immunohistochemical expression of MUC2. The clinicopathological parameters were also examined. This study was conducted at the Pathology Department, Pakistan Institute of Medical Sciences (PIMS), Peshawar, between January 2019 to January 2021. A nonprobability sampling technique was used while collecting the samples. SPSS version 21 was used and p-value

Background & aimsAlthough Clostridioides difficile infection (CDI) is known to involve the disruption of the gut microbiota, little is understood regarding how mucus-associated microbes interact with C difficile. We hypothesized that select mucus-associated bacteria would promote C difficile colonization and biofilm formation.MethodsTo create a model of the human intestinal mucus layer and gut microbiota, we used bioreactors inoculated with healthy human feces, treated with clindamycin and infected with C difficile with the addition of human MUC2-coated coverslips.ResultsC difficile was found to colonize and form biofilms on MUC2-coated coverslips, and 16S rRNA sequencing showed a unique biofilm profile with substantial cocolonization with Fusobacterium species. Consistent with our bioreactor data, publicly available data sets and patient stool samples showed that a subset of patients with C difficile infection harbored high levels of Fusobacterium species. We observed colocalization of C difficile and F nucleatum in an aggregation assay using adult patients and stool of pediatric patients with inflammatory bowel disease and in tissue sections of patients with CDI. C difficile strains were found to coaggregate with F nucleatum subspecies in vitro; an effect that was inhibited by blocking or mutating the adhesin RadD on Fusobacterium and removal of flagella on C difficile. Aggregation was shown to be unique between F nucleatum and C difficile, because other gut commensals did not aggregate with C difficile. Addition of F nucleatum also enhanced C difficile biofilm formation and extracellular polysaccharide production.ConclusionsCollectively, these data show a unique interaction of between pathogenic C difficile and F nucleatum in the intestinal mucus layer.

Mucin‐2 (MUC2) secreted by goblet cells participates in the intestinal barrier, but its mechanism in acute necrotizing pancreatitis (ANP) remains unclear. In acute pancreatitis (AP) patients, the functions of goblet cells (MUC2, FCGBP, CLCA1, and TFF3) decreased, and MUC2 was negatively correlated with AP severity. ANP rats treated with pilocarpine (PILO) (PILO+ANP rats) to deplete MUC2 showed more serious pancreatic and colonic injuries, goblet cell dysfunction, gut dysbiosis, and bacterial translocation than those of ANP rats. GC‐MS analysis of feces showed that PILO+ANP rats had lower levels of butyric acid, isobutyric acid, isovaleric acid, and hexanoic acid than those of ANP rats. The expression of MUC2 was associated with colonic injury and gut dysbiosis. All these phenomena could be relieved, and goblet cell functions were also partially reversed by MUC2 supplementation in ANP rats. TNF‐α‐treated colonoids had exacerbated goblet cell dysfunction. MUC2 expression was negatively correlated with the levels of pro‐inflammatory cytokines (IL‐1β and IL‐6) (p <.05) and positively related to the expression of tight junction proteins (Claudin 1, Occludin, and ZO1) (p <.05). Downregulating MUC2 by siRNA increased the levels of the pro‐inflammatory cytokines in colonoids. MUC2 might maintain intestinal homeostasis to alleviate ANP. [ABSTRACT FROM AUTHOR]

Colon mucus segregates the intestinal microbiota from host tissues, but how it organizes to function throughout the colon is unclear. In mice, we found that colon mucus consists of two distinct O-glycosylated entities of Muc2: a major form produced by the proximal colon, which encapsulates the fecal material including the microbiota, and a minor form derived from the distal colon, which adheres to the major form. The microbiota directs its own encapsulation by inducing Muc2 production from proximal colon goblet cells. In turn, O-glycans on proximal colon-derived Muc2 modulate the structure and function of the microbiota as well as transcription in the colon mucosa. Our work shows how proximal colon control of mucin production is an important element in the regulation of host-microbiota symbiosis.

The gastrointestinal (GI) tract can play a critical role in the development of pathologies associated with overeating, overweight and obesity. We previously observed that supplementation with anthocyanins (AC) (particularly glycosides of cyanidin and delphinidin) mitigated high fat diet (HFD)-induced development of obesity, dyslipidemia, insulin resistance and steatosis in C57BL/6J mice. This paper investigated whether these beneficial effects could be related to AC capacity to sustain intestinal monolayer integrity, prevent endotoxemia, and HFD-associated dysbiosis. The involvement of redox-related mechanisms were further investigated in Caco-2 cell monolayers. Consumption of a HFD for 14 weeks caused intestinal permeabilization and endotoxemia, which were associated with a decreased ileum expression of tight junction (TJ) proteins (occludin, ZO-1 and claudin-1), increased expression of NADPH oxidase (NOX1 and NOX4) and NOS2 and oxidative stress, and activation of redox sensitive signals (NF-κB and ERK1/2) that regulate TJ dynamics. AC supplementation mitigated all these events and increased GLP-2 levels, the intestinal hormone that upregulates TJ protein expression. AC also prevented, in vitro, tumor necrosis factor alpha-induced Caco-2 monolayer permeabilization, NOX1/4 upregulation, oxidative stress, and NF-κB and ERK activation. HFD-induced obesity in mice caused dysbiosis and affected the levels and secretion of MUC2, a mucin that participates in intestinal cell barrier protection and immune response. AC supplementation restored microbiota composition and MUC2 levels and distribution in HFD-fed mice. Thus, AC, particularly delphinidin and cyanidin, can preserve GI physiology in HFD-induced obesity in part through redox-regulated mechanisms. This can in part explain AC capacity to mitigate pathologies, i.e. insulin resistance and steatosis, associated with HFD-associated obesity.

Introduction: Alcohol-induced thickening of the gut mucosal layer and increased expression of goblet cell gel-forming mucins, such as mucin-2 (MUC2) are associated with disruptions to the gut barrier in alcoholic liver disease (ALD). Interest in drugs that can target gut mucins in ALD has grown; however to date, no studies have examined the properties of drugs on expression of gut mucins in models of ALD. We previously demonstrated that at 10 mg/kg/day, the drug fenretinide (N-[4-hydroxyphenyl] retinamide [Fen]), a synthetic retinoid, mitigates alcohol-associated damage to the gut barrier and liver injury in a murine model of ALD. Methods: In this study, we specifically sought to examine the effects of Fen on gut goblet cells, and expression of mucins, including MUC2 using a 25-day Lieber-DeCarli model of chronic alcohol intake. Results: Our results show that chronic alcohol intake increased gut-mucosal thickening, goblet cell numbers, and mRNA and protein expression of MUC2 in both the ileum and colon. Alcohol intake was associated with marked decreases in ileal and colonic Notch signaling, levels of Notch ligands Dll1 and Dll4, and increases in the expression of Notch-associated genes indispensable for goblet cell specification, including Math1 and Spdef. Interestingly, ileal and colonic expression of KLF4, which is involved in terminal differentiation of goblet cells, was reduced in mice chronically fed alcohol. Coadministration of alcohol with Fen at 10 mg/kg/day significantly reduced alcohol-associated increases in ileal and colonic mucosal thickening, ileal Muc2, colonic Muc2, Muc5ac and Muc6 mRNAs, and goblet cell numbers. We also found that Fen strongly prevented alcohol-mediated suppression of the Notch ligand Dll1, Notch signaling, and alcohol-induced increases in expression of Notch-associated goblet cell specification genes in both the ileum and colon. In the absence of alcohol, Fen treatments alone at 10 mg/kg/day had no effects on any of the goblet cell-related endpoints. Conclusion: These data show for the first time that the drug Fen possesses mucosal layer-modulating properties in response to chronic alcohol abuse. These data warrant further preclinical examination of Fen given the need for anti-ALD drugs and emerging evidence of a role for intestinal goblet cell mucins in the progression of ALD. [ABSTRACT FROM AUTHOR]

Objective: To study the effect of Wenglian jiedu decoction on the expression of serum interleukin-18 (IL-18), tumor necrosis factor-α (TNF--α) and colonic mucin-2 (MUC2) in rats with ulcerative colitis of turbid toxin type, and to explore its mechanism. Methods: 60 Wistar male rats were randomly divided into model group, Wenglian jiedu decoction low, middle and high dose groups, mesalazine group and blank group. Except for the blank group, the rat model of ulcerative colitis was established by trinitrobenzenesulfonic acid (TNBS) / ethanol compound method. The general condition, body weight, fecal properties and occult blood of rats were observed 2 weeks after administration. The disease activity index (Diseaseactivityindex,DAI) was scored, the content of MUC2 protein was detected by immunohistochemical method, and the contents of IL-18 and TNF-α in serum were detected by enzyme-linked immunosorbent assay (Elisa). Results: compared with the blank group, the DAI score increased, the contents of IL-18 and TNF-α increased significantly, and the content of MUC2 protein decreased in the model group. Compared with the model group, the DAI score, the content of IL-18 and TNF-α decreased and the content of MUC2 protein increased in each treatment group. Compared with the mesalazine group, the DAI score and the contents of IL-18 and TNF-α in the high and middle dose groups had no significant difference. Compared with the low dose group, the DAI score in the mesalazine group and the high and middle dose group decreased, and the contents of IL-18 and TNF-α decreased. Conclusion: Wenglian jiedu decoction can regulate the immune system of intestinal epithelium by regulating the levels of serum IL-18 and TNF-α and increasing the expression of MUC2 protein, so as to achieve the purpose of repairing intestinal mucosa. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effects of exposure to endotoxin on the reproductive performance of humans and animals in pregnancy and delivery period. Mucin is considered to play a critical role in protecting the tissue epithelium. At pregnancy period, the MUC2 expression of uterus in the High LPS group was significantly higher than that in the Control group. The glycosaminoglycans of gland cells were secreted into the uterine cavity to protect the uterus. Then, the MUC2 layer became thinner, and LPS entered the lamina propria of the uterus. The mRNA expression of tight junction proteins showed a marked drop, and morphological damage of the uterus occurred. Subsequently, the glycosaminoglycans of gland cells in the High LPS and Low LPS groups increased with the increasing LPS dose, and the damage to the endometrial epithelium was repaired in female mice at Day 5 postdelivery. A low dose of LPS activated the PI3K/AKT signaling pathways to increase the glycosaminoglycans particles, while a high dose of LPS inhibited the PI3K/AKT signaling pathway to decrease the glycosaminoglycans particles. Taken together, our results suggest that gland cells secreted glycosaminoglycans particles into the uterine cavity by exocytosis to increase the thickness of the mucus layer to protect the uterus and that this process was regulated by PI3K/AKT signaling pathways.

Background: Intestinal barrier dysfunction is a significant contributor to the recurrence and refractory of ulcerative colitis (UC). Promoting the interaction between group 3 innate lymphoid cells (ILC3s) and gut flora is a valuable strategy for mucosal repair. Paeoniae decoction (PD) is a compound commonly used in clinical treatment of UC, but its exact mechanism remains unclear., Purpose: We aimed to investigate the protective effect of PD on intestinal mucosal injury induced by dextran sulfate sodium (DSS) in chronic colitis, as well as to elucidate its potential mechanism., Methods: C57BL/6 mice were induced with chronic colitis by 2 % DSS and divided into four groups: control group, model group, PD low dose (4 g/kg), and high dose (8 g/kg) group. The effectiveness of PD in treating chronic colitis mice was evaluated based on changes in body weight, colon length, colon pathological tissue scores, and the mRNA levels of inflammatory factors IL-6 and IL-1β. The expressions of intestinal epithelial tight junction proteins (ZO-1 and Occludin), IL-22, and MUC2 were observed using immunofluorescence and RT-PCR. Additionally, the proportion of ILC3 and natural cytotoxicity receptor (NCR) + ILC3 in the colon were detected using flow cytometry. Furthermore, UHPLC-QE-MS was utilized to identify chemical components of PD and network pharmacology was employed to predict potential pathways for PD intervention in UC. Subsequently, MNK-3 cells (ILC3 in vitro cell line) and NCM460 cells were used to verify the network pharmacology results. Finally, the effects of PD on UC gut flora have been explored using in vitro fermentation and 16S rDNA techniques., Results: The results showed that PD significantly restored body weight and colon length in mice with chronic colitis, while also reducing colon inflammatory cell infiltration and the expression of IL-6 and IL-1β. Additionally, PD notably promoted the expression of MUC2, ZO-1, Occludin, and IL-22, as well as increasing the ratio of ILC3 and NCR + ILC3. UHPLC-QE-MS analysis identified 443 components of PD, and network pharmacology suggested that PD could target the aryl hydrocarbon receptor (AHR) signaling pathway, which was confirmed by MNK-3 cells and in vitro fermentation experiments. Furthermore, MNK-3-conditioned medium (CM) increased the expression of ZO-1 and Occludin in NCM460 cells. In addition, 16S rDNA results indicated that PD promoted the abundance of Lactobacillales, thus contributing to mucosal damage repair by activating the AHR signal in ILC3s., Conclusion: In summary, our study demonstrates that PD repairs intestinal mucosal damage in chronic colitis by regulating the interaction of gut flora with ILC3, and the specific mechanism is related to the activation of AHR signaling pathway., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

The aim of this study was to determine the effects of deoxynivalenol (DON) contaminated diet on performance, immune system, gut morphology and jejunal gene expression in broiler chickens. Eighty-one-day old chicks were randomly allotted into two treatments with 4 replicates (10 birds in each replication). Experimental diets were the control diet (maize-soybean meal) and an experimentally contaminated diet with 10 mg/kg DON. The results indicated that DON-challenged birds had decreased (P < 0.05) average feed intake (AFI) during starter period as compared to control group. Also, average daily gain (ADG), AFI and feed conversion ratio (FCR) were not affected (P > 0.05) by inclusion of DON contaminated diet during the whole experimental period. Dietary addition of DON to the basal diet caused Fabricius bursa relative weight reduction, while increased the abdominal fat and serum triglyceride (TG) concentration (P < 0.05). Dietary DON feeding caused an enhancement (P < 0.05) in the blood aspartate aminotransferase (AST) and gamma glutamytransferase (GGT) contents. Moreover, DON decreased the serum total protein (TP) and albumin (ALB) concentrations. Inclusion of DON in diet reduced (P < 0.05) the white blood cell (WBC) count, lymphocyte number and antibody titer against Newcastle disease virus, but increased (P < 0.05) the blood heterophil count. The DON consumption also diminished (P < 0.05) the villus height, villus to crypt ratio, mucosa thickness and villus surface area in the duodenum. Mucin-2 expression was decreased (P < 0.05) by DON consumption, but toll-like receptor-4 (TLR-4) and claudin-5 (CLDN-5) expressions were not affected (P > 0.05) by dietary treatments. In conclusion, although DON could not influence the performance attributes in broiler chickens, it adversely affected the immune response, muc-2 gene expressions in the jejunum and gut morphology, enhanced the liver enzyme indices and lessened the blood protein contents. [Display omitted] • Deoxynivalenol contaminated diets disturb mucin-2 gene expression in jejunum and reduce mucosa layer thickness. • Deoxynivalenol exposure causes biochemical changes. • Deoxynivalenol decrease immunological parameters and antibody titer against Newcastle virus disease. [ABSTRACT FROM AUTHOR]

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.

This study aimed to investigate the effects of early or late feeding strategies and prebiotic, on immune responses and gut health during the early life stage of broiler chickens. A total of 240 day-old male broiler chicks were used in a 2 × 3 factorial arrangement of treatments that comprised 2 feeding strategies (early or late) and 3 levels of prebiotic (0, recommended dosage or three times the recommended dosage) in a completely randomized design with 4 pen replicates and 10 broilers per each. Compared to broiler chickens that had early access to feed, delayed access to feed resulted in an increased population of Escherichia coli and a decreased population of Lactobacillus spp. and Bifidobacterium spp. in the ileum (P < 0.05). Additionally, delayed access to feed led to a decrease in villus height, crypt depth, villus height: villus width ratio, goblet cell density, and mucin 2 gene expression in the ileum (P < 0.05). The supplementation of prebiotics in both the late and early feeding strategy groups resulted in increased villus height, crypt depth, goblet cell density, mucin 2 gene expression, and antibodies against Infectious Bursal Disease (IBD). Additionally, it led to an improvement in the foot web thickness index (P < 0.05). Furthermore, it resulted in a significant decrease in the population of Escherichia coli, while the populations of Lactobacillus spp. and Bifidobacterium spp. in the ileum were significantly increased (P < 0.05). Therefore, this study suggests that incorporating prebiotics in the starter diet can effectively enhance immune responses and promote gut health, regardless of the feeding strategy (early or late). In conclusion, this study demonstrates the potential benefits of incorporating prebiotics into poultry diets to alleviate the detrimental effects of delayed access to feed and improve gut health during the early life stage of broiler chickens., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Glandular odontogenic cysts (GOCs) and dentigerous cysts may show mucous metaplasia. Central mucoepidermoid carcinoma is very rare and mostly associated with dental cysts. It is hypothesized that odontogenic cysts showing mucus differentiation in their lining, have a propensity to transform into MEC. The present study is the first attempt to explore the relationship between odontogenic cysts [GOCs and dentigerous cysts with mucus metaplasia (DCMM)] and MEC by evaluating immunoexpression of MUC5AC and MUC2. Immunoexpression of MUC5AC and MUC2 was evaluated semiquantitatively in GOCs (20 cases), DCMMs (20 cases), and MECs (20 cases). The percentage of positive cells, intensity, and localization of immunoexpression were assessed for each marker in all cases. Of GOCs, DCMMs, and MECs cases, 85%, 70%, and 80%, respectively, were immunopositive for MUC5AC. Strong cytoplasmic immunoreactivity for MUC5AC was noted, particularly in mucous cells present diffusely within MECs. However, the immunoreactivity was limited to the epithelial lining of GOCs and DCMMs. Most of the MECs (60%) showed more than 25% positivity for MUC5AC, followed by GOCs, and the least in DMMCs. Mild cytoplasmic and nuclear positivity of MUC2 was noted only in epithelial lining cells of 70% GOCs and 45% DCMMs. Whereas, 55% of MECs displayed moderate to strong cytoplasmic and membranous immunopositivity for MUC2 exclusively within mucous cells. As MECs showed strong MUC5AC immunoreactivity in mucous cells, immunoexpression of MUC5AC in odontogenic cysts with mucus cells can possibly explain the pathogenesis of MEC from cysts. However, the variable expression of MUC2 did not give any strong evidence regarding its role as a marker., Competing Interests: The authors declare no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

• The diagnosis of IPMN has increased in recent years. • Correctly identifying Mixed-Type IPMNs is related to the potential of these lesions for malignant transformation. • Decision making and meticulous follow-up of the remaining pancreatic parenchyma should be considered. With the greater availability of imaging exams, the diagnosis of intraductal papillary mucinous neoplasms (IPMNs) has increased recently. However, there are still questions about adequate management approaches for this disease, especially regarding the best therapeutic strategy. The objective is to describe the case of a patient with mixed-type (MT) IPMN successfully treated by a tailored surgical plan that adopted duodenopancreatectomy and imaging to monitor the remaining lesions of the tail and body of the pancreas. A 65-year-old asymptomatic man underwent ultrasonography of the abdomen and was diagnosed with a cystic tumor, measuring 3.0 × 2.5 cm, located on the head of the pancreas. Magnetic resonance cholangiopancreatography (MRCP) showed dilation of the main pancreatic duct and multiple cystic lesions scattered throughout the entire parenchyma. The patient underwent duodenopancreatectomy; postoperatively, he did not have complications and was discharged on the 6th postoperative day. The histopathological panel confirmed the presence of MT-IPMN of the intestinal pattern. The patient is currently well four years after surgery and is undergoing semiannual MRCP examinations to follow up the remaining lesions. MT-IPMNs represent 28–41% of all IPMNs. Among all subtypes, MT-IPMNs are the most challenging in terms of choosing the ideal therapeutic strategy. These lesions are the most difficult to treat because they can be multifocal and compromise different locations of the pancreatic parenchyma. MRI findings, Ca19.9 serum level and negative family history of pancreatic neoplasia were indications for the surgical choice for the MT- IPMN presented in this case. [ABSTRACT FROM AUTHOR]

Human exposure to a wide variety of engineered nanoparticles (NPs) is on the rise and use in common food additives increases gastrointestinal (GI) exposure. Host health is intricately linked to the GI microbiome and immune response. Perturbations in the microbiota can affect energy harvest, trigger inflammation and alter the mucosal barrier leading to various disease states such as obesity and inflammatory bowel diseases. We hypothesized that single high‐dose titanium dioxide (TiO2) NP exposure in mice would lead to dysbiosis and stimulate mucus production and local immune populations. Juvenile mice (9‐10 weeks) were gavaged with 1 g/kg TiO2 NPs and examined for changes in mucosa‐associated bacteria abundance, inflammatory cytokines, mucin expression and body mass. Our data provide support that TiO2 NP ingestion alters the GI microbiota and host defenses promoting metabolic disruption and subsequently weight gain in mice. We evaluated gut homeostasis of juvenile mice following a high, acute dose of TiO2 nanoparticles (NPs). The treatment promoted weight gain, possibly due to an overgrowth of Firmicutes, an important player in energy harvest from the diet. Increased expression of mucin and production of immune mediators illustrates activation of inflammatory signaling. In conclusion, our study points to a possible role of environmental exposure to TiO2 NPs in dysbiosis and weight gain, particularly in growing mammals. [ABSTRACT FROM AUTHOR]

ABSTRACT Background: The effects of topical application of sucralfate (SCF) on the tissue content of MUC-2 protein have not yet been evaluated in experimental models of diversion colitis. Aim: To measure the tissue content of MUC-2 protein in the colonic mucosa diverted from fecal stream submitted to the SCF intervention. Methods: Thirty-six rats underwent derivation of intestinal transit through proximal colostomy and distal mucous fistula. The animals were divided into three groups which were submitted application of enemas with saline, SCF 1 g/kg/day and SCF 2 g/kg/day. Each group was divided into two subgroups, according to euthanasia was done after two or four weeks. The colitis diagnosis was established by histopathological study and the inflammatory intensity was evaluated by previously validated scale. The MUC-2 protein was identified by immunohistochemistry and the tissue content was measured computerized morphometry). Results: The application of enemas with SCF in the concentration of 2 g/kg/day reduced inflammatory score of the segments that were diverted from fecal stream. The content of MUC-2 in diverted colon of the animals submitted to the intervention with SCF, independently of intervention period and the used concentration, was significantly greater than animals submitted to the application of enemas containing saline (p< 0.01). The content of MUC-2 after the intervention with SCF in the concentration of 2 g/kg/day was significantly higher when compared to the animals submitted to the application containing SCF at concentration of 1.0 g/kg/day (p

Ethnopharmacological Relevance: The herb pair Astragali Radix (AR) and Curcumae Rhizoma (vinegar-processed, VPCR), derived from the traditional Chinese medicine (TCM) text 'Yixuezhongzhongcanxilu', have long been used to treat gastrointestinal diseases, notably colitis-associated colorectal cancer (CAC). Hedysari Radix (HR), belonging to the same Leguminosae family as AR but from a different genus, is traditionally used as a substitute for AR when paired with VPCR in the treatment of CAC. However, the optimal compatibility ratio for HR-VPCR against CAC and the underlying mechanisms remain unclear., Aim of the Study: To investigate the optimal compatibility ratio and underlying mechanisms of HR-VPCR against CAC using a combination of comparative pharmacodynamics, network pharmacology, and experimental verification., Materials and Methods: The efficacy of different compatibility ratios of HR-VPCR against CAC was evaluated using various indicators, including the body weight, colon length, tumor count, survival rate, disease activity index (DAI) score, Haemotoxylin and Eosin (H&E) pathological sections, inflammation cytokines (IL-1β, IL-6, IL-10, TNF-α), tumor markers (K-Ras, p53), and intestinal permeability proteins (claudin-1, E-cadherin, mucin-2). Then, the optimal compatibility ratio of HR-VPCR against CAC was determined based on the fuzzy matter-element analysis by integrating the above indicators. After high-performance liquid chromatography (HPLC) analysis for the optimal compatibility ratio of HR-VPCR, potential active components of HR-VPCR were identified by TCMSP and the previous bibliographies. Swiss Targets and GeneCards were adopted to predict the targets of the active components and the targets of CAC, respectively. Then, the common targets of HR-VPCR against CAC were obtained by Venn analysis. PPI networks were constructed in STRING. GO and KEGG enrichments were visualized by the David database. Finally, the predicted pathway was experimentally validated via Western blot., Results: Various compatibility ratios of HR-VPCR demonstrated notable therapeutic effects to some extent, evidenced by improvements in body weight, colon length, tumor count, pathological symptoms (DAI score), colon and organ indexes, survival rate, and modulation of inflammation factors (IL-1β, IL-6, IL-10, TNF-α), as well as tumor markers (K-Ras, p53), and down-regulation of intestinal permeability proteins (claudin-1, E-cadherin, mucin-2) in CAC mice. Among these ratios, the ratio 4:1 represents the optimal compatibility ratio by the fuzzy matter-element analysis. Thirty active components of HR-VPCR were carefully selected, targeting 553 specific genes. Simultaneously, 2022 targets associated with CAC were identified. 88 common targets were identified after generating a Venn plot. Following PPI network analysis, 29 core targets were established, with AKT1 ranking highest among them. Further analysis via GO and KEGG enrichment identified the PI3K-AKT signaling pathway as a potential mechanism. Experimental validation confirmed that HR-VPCR intervention effectively reversed the activated PI3K-AKT signaling pathway., Conclusions: The optimal compatibility ratio for the HR-VPCR herb pair in alleviating CAC is 4:1. HR-VPCR exerts its effects by alleviating intestinal inflammation, improving intestinal permeability, and regulating the PI3K-AKT signaling pathway., Competing Interests: Declaration of competing interest This manuscript has not been published or presented elsewhere in part or in entirety, and is not under consideration by another journal. The study was preformed in accordance with institutional guidelines for the care and use of experimental animals. All the authors have approved the manuscript and agree with submission to your esteemed journal. There are declare no conflicts of interest to declare., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Prenatal dexamethasone exposure (PDE) can lead to increased susceptibility to various diseases in adult offspring, but its effect on gut microbiota composition and the relationship with disease susceptibility remains unclear. In this study, we find sex-differential changes in the gut microbiota of 6-month-old infants with prenatal dexamethasone therapy (PDT) that persisted in female infants up to 2.5 years of age with altered bile acid metabolism. PDE female offspring rats show abnormal colonization and composition of gut microbiota and increased susceptibility to cholestatic liver injury. The aberrant gut microbiota colonization in the PDE offspring can be attributed to the inhibited Muc2 expression caused by decreased CDX2 expression before and after birth. Integrating animal and cell experiments, we further confirm that dexamethasone could inhibit Muc2 expression by activating GR/HDAC11 signaling and regulating CDX2 epigenetic modification. This study interprets abnormal gut microbiota and disease susceptibility in PDT offspring from intrauterine intestinal dysplasia., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

In the intestine, mucus covering the mucosa plays a critical role in maintaining gut homeostasis by protecting the mucosa from invasion by commensal bacteria. The gut mucus is composed primarily of MUC2 mucin secreted by goblet cells. MUC2 is highly O-glycosylated, and O-glycans are necessary for the function and polymer structure of MUC2. In addition, recent evidence revealed that several glycan modifications, such as sialylation and sulfation, confer resistance of mucins to proteolysis and affect the viscosity and lubricity of mucus. Therefore, characterizing glycan structures of mucins is required to understand their functions fully. In this chapter, we describe how to purify secreted mucins from the mammalian intestine for analysis of their glycan structures. This description includes the extraction of MUC2 mucin from the mucosal surface of the mouse colon and colon explants., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: Chinese Herb QingBai decoction (QBD) has been approved affective in the treatment of IBD patients in clinic. However, the underlying mechanism remains unknown. We aim to investigate the effect of QBD on the mouse model of ulcerative colitis and its possible mechanism. Methods: C57/bL mice were given 5% DSS to induce colitis and were divided as QBD and mesalazine group. Weight, faeces and mental status were recorded each day and the histopathological changes (goblet cells etc) of the colon were observed after sacrificed. Fluorescein isothiocyanate‐dextran 4000 was measured to reflect the intestinal mucosal permeability. In addition, cell junction‐related proteins and possible signal pathways were investigated. Results: QingBai decoction could significantly alleviate the inflammation and the protection effect of colitis is comparable as those in mesalazine enema group. It was found that the permeability reduced significantly with QBD treatment vs the control group, while no significant difference between the mesalazine and QBD groups. QBD treatment could upregulate the expression of tight junction complex（ZO‐1, claudin‐1 and occludin）and muc‐2 expression. It significantly reduced the production and secretion of serials proinflammatory cytokines (IL‐1β, IL‐6, Kc and TNF‐α) compared with the control group. Meanwhile, NF‐κB and Notch pathways were regulated. Conclusion: QingBai decoction can effectively alleviate intestinal inflammation and mucosal barrier function in colitis mice, and the mechanism may be related to the inhibition of inflammatory cascade as well as enhanced mucus layer barrier and mechanical barrier function by NF‐κB and Notch signalling. [ABSTRACT FROM AUTHOR]

Probiotics have been widely used in maintaining gastrointestinal health, despite their actual mechanism remaining obscure. There are several hypotheses behind the beneficial effects of probiotics including the regulation of intestinal barrier function and improvement in immune responses in the gastrointestinal system. Multiple probiotics have been introduced in the market as effective dietary supplements in improving gastrointestinal integrity, but there are no or few studies that demonstrate their underlying mechanism. In the current study, we investigated and compared the efficacy of four probiotics (based on different bacterial species) in refining gastrointestinal health by improving mucus biosynthesis and intestinal immune response under in-vitro conditions. By analyzing the gene expression of mucus biosynthesis and intestinal immune response markers, we found that probiotic Streptococcus thermophilus UASt-09 showed promising potential in refining mucosal barrier and gastrointestinal health in human colonic epithelial cells, as compared to other commercial probiotics.

ABSTRACT Background: The effects of topical application of sucralfate (SCF) on the tissue content of MUC-2 protein have not yet been evaluated in experimental models of diversion colitis. Aim: To measure the tissue content of MUC-2 protein in the colonic mucosa diverted from fecal stream submitted to the SCF intervention. Methods: Thirty-six rats underwent derivation of intestinal transit through proximal colostomy and distal mucous fistula. The animals were divided into three groups which were submitted application of enemas with saline, SCF 1 g/kg/day and SCF 2 g/kg/day. Each group was divided into two subgroups, according to euthanasia was done after two or four weeks. The colitis diagnosis was established by histopathological study and the inflammatory intensity was evaluated by previously validated scale. The MUC-2 protein was identified by immunohistochemistry and the tissue content was measured computerized morphometry). Results: The application of enemas with SCF in the concentration of 2 g/kg/day reduced inflammatory score of the segments that were diverted from fecal stream. The content of MUC-2 in diverted colon of the animals submitted to the intervention with SCF, independently of intervention period and the used concentration, was significantly greater than animals submitted to the application of enemas containing saline (p< 0.01). The content of MUC-2 after the intervention with SCF in the concentration of 2 g/kg/day was significantly higher when compared to the animals submitted to the application containing SCF at concentration of 1.0 g/kg/day (p

Abnormal synthesis of the main intestinal proteo­glycan mucin-2 is typical of ulcerative colitis and Crohn’s disease in humans. Those morphological changes of the mucus layer affect the diversity of the intestinal microflora. Antibiotics may be ineffective or even dangerous to humans or animals deficient for mucin-2 because of the risk of sepsis and chronic inflammation. In this study, we investigated the potential of antibiotics (clarithromycin, amoxicillin, and metronidazole) in elimination of patho­genic infection from Muc2 knockout mice (Muc2–/–). We assayed the population sizes of pathogens (Heli­co­bacter spp.) and symbiotic (E. coli) bacteria in the intestines of animals as a criterion of antibiotic efficacy. The damaging effect of antibacterial treatment on the host body was estimated from their survival rate. Three antibiotics were ineffective in the elimination of Helicobacter spp. from mucin-2-deficient mice. Moreover, the mortality of Muc2 knockout mice during the antibacterial treatment was 60 %. The survival of wild-type mice (C57BL/6J) during the treatment was 100 %. The weight of wild-type mice showed no decrease during the treatment. The Helico­bacter spp. pathogen was fully eradicated from wild-type mice. Thus, therapy of Helicobacter spp. infection in mucin-2 deficient animals is not only poorly efficient but even deadly. The high susceptibility to antibiotics allows Muc2 knockout mice to be used as a test model to evaluate the pharmacological safety of new antibiotics.

Background: Evodia Rutaecarpa-processed Coptidis Rhizoma (ECR) is a traditional Chinese medicine for the treatment of ulcerative colitis (UC) in China. However, the mechanisms underlying the ECR processing are not elucidated., Purpose: Coptidis Rhizoma (CR) regulates the gut microbiota in the treatment of gastrointestinal diseases. This study explored the mechanism of action of ECR before and after processing in UC in view of the regulation of gut microecology., Study Design: A preclinical experimental investigation was performed using a mouse model of UC to examine the regulatory effect of ECR and its mechanisms through gut microbiota analysis and metabolomic assays., Methods: Mice received 4% dextran sulfate sodium to establish a UC model and treated with ECR and CR. Colonic histopathology and inflammatory changes were observed. Gut microbiota was analyzed using 16 s rRNA sequencing. Transplants of Lactobacillus reuteri were used to explore the correlation between ECR processing and the gut microbiota. The expression of mucin-2, Lgr5, and PCNA in colonic epithelial cells was measured using immunofluorescence. Wnt3a and β-catenin levels were detected by western blotting. The metabolites in the colon tissue were analyzed using a targeted energy metabolomic assay. The effect of energy metabolite α-ketoglutarate (α-KG) on L. reuteri growth and UC were verified in mice., Results: ECR improved the effects on UC in mice compared to CR, including alleviating colonic injury and inflammation, and modulating gut microbiota by increasing L. reuteri level. L. reuteri dose-dependently alleviated colonic injury, increased mucin-2 level, and promoted colonic epithelial regeneration by increasing Lgr5 and PCNA expression. This was consistent with the results before and after ECR processing. L. reuteri promoted epithelial regeneration by upregulating Wnt/β-catenin pathway. Moreover, ECR increased metabolites levels (especially α-KG) to promote energy metabolism in the colon tissue compared to CR. α-KG treatment increased L. reuteri level and alleviated mucosal damage in UC mice. It promoted L. reuteri growth by increasing the energy metabolic status by enhancing α-KG dehydrogenase activity., Conclusion: ECR processing improves the therapeutic effects of UC via the α-KG-L. reuteri-epithelial regeneration axis., Competing Interests: Declaration of Competing Interest The Authors have no relevant interests to disclose. The authors have no conflicts of interest to declare that are relevant to the content of this article., (Copyright © 2023. Published by Elsevier GmbH.)

Chronic stress is known to promote inflammatory bowel disease (IBD), but the underlying mechanism remains largely unresolved. Here, we found chronic stress to sensitize mice to dextran sulfate sodium (DSS)-induced colitis; to increase the infiltration of B cells, neutrophils, and proinflammatory ly6Chi macrophages in colonic lamina propria; and to present with decreased thymus and mesenteric lymph node (MLN) coefficients. Circulating total white blood cells were significantly increased after stress, and the proportion of MLN-associated immune cells were largely changed. Results showed a marked activation of IL-6/STAT3 signaling by stress. The detrimental action of stress was not terminated in IL-6-/- mice. Interestingly, the composition of gut microbiota was dramatically changed after stress, with expansion of inflammation-promoting bacteria. Furthermore, results showed stress-induced deficient expression of mucin- 2 and lysozyme, which may contribute to the disorder of gut microbiota. Of note is that, in the case of cohousing, the stress-induced immune reaction and decreased body weight were abrogated, and transferred gut microbiota from stressed mice to control mice was sufficient to facilitate DSS-induced colitis. The important role of gut microbiota was further reinforced by broad-spectrum antibiotic treatment. Taken together, our results reveal that chronic stress disturbs gut microbiota, triggering immune system response and facilitating DSS-induced colitis. [ABSTRACT FROM AUTHOR]

Antibodies of the secretory IgA (SIgA) class comprise the first line of antigen-specific immune defense, preventing access of commensal and pathogenic microorganisms and their secreted products into the body proper. In addition to preventing infection, SIgA shapes the composition of the gut microbiome. SIgA is transported across intestinal epithelial cells into gut secretions by the polymeric immunoglobulin receptor (pIgR). The epithelial surface is protected by a thick network of mucus, which is composed of a dense, sterile inner layer and a loose outer layer that is colonized by commensal bacteria. Immunofluorescence microscopy of mouse and human colon tissues demonstrated that the SIgA co-localizes with gut bacteria in the outer mucus layer. Using mice genetically deficient for pIgR and/or mucin-2 (Muc2, the major glycoprotein of intestinal mucus), we found that Muc2 but not SIgA was necessary for excluding gut bacteria from the inner mucus layer in the colon. Our findings support a model whereby SIgA is anchored in the outer layer of colonic mucus through combined interactions with mucin proteins and gut bacteria, thus providing immune protection against pathogens while maintaining a mutually beneficial relationship with commensals.