Search

Objective: To investigate the effect of paeoniflorin on the intestinal barrier function and ERK signaling pathway during the occurrence of ulcerative colitis (UC). Methods: Twenty-four SPF male Sprague-Dawley (SD) rats aged 7-8 weeks were randomly divided into 4 groups: normal group (Normal group, rats without modeling and administration), TNBS model group (Model group, 100 mg/kg TNBS administration model), low-dose paeoniflorin group (LPF group, 100 mg/kg TNBS + 10 mg/kg paeoniflorin administration treatment), high-dose paeoniflorin group (HPF group, 100 mg/kg TNBS + 100 mg/kg paeoniflorin administration treatment), Each group had 6 rats. Rats were given a bolus injection of 5% trinitrobenzene sulfonic acid (TNBS) for UC modeling, and then the designated concentration of paeoniflorin was intragastrically administered. Continuous treatment for 14 d. Histopathological observation was performed by hematoxylin and eosin (HE) staining, and the thickness of colon mucus layer was calculated by alcian blue (AB) staining. The levels of cytokines (IL-6, IL-1β, TNF-α and IL-10), myeloperoxidase (MPO) and mucin (MUC2 and MUC5AC) in colon tissue was analyzed by ELISA. The protein expression of IL-6 and IL-10 in the colon tissue of rats in each group was detected by immunohistochemistry. The protein expression of protein kinase Cα (PKCα ), p-PKCα, ERK1/2 and p-ERK1/2 was analyzed by Western blotting. Results: Compared with Model group(8.38± 0.42 cm), the colon length of UC rats in LPF group(9.88± 0.49 cm) and HPF group (10.92± 0.55 cm) increased significantly(P<0.05). Compared with Model group(22.54± 1.13 μm), the thickness of the colonic mucus layer of UC rats in LPF group (41.07± 2.05 μm) and HPF group (50.33± 2.52 μm) increased significantly(P<0.05). Compared with Model group, the colon morphology of the UC rats in LPF group and HPF group was significantly improved, the levels of IL-6, IL-1β, TNF-α and MPO in the colon tissue were significantly reduced, while IL-10 was significantly increased (P<0.05). Compared with Model group, the levels of MUC2 and MUC5AC in the colon tissue of UC rats in the LPF group and the HPF group were significantly increased, and the phosphorylation levels of p-PKCα and p-ERK1/2 were also significantly increased(P<0.05). Conclusion: Paeoniflorin inhibits TNBS-induced colonic inflammation in UC rats and increases the thickness of the colonic mucus layer, thereby protecting the intestinal barrier function, the mechanism may be related to the activation of the ERK signaling pathway. [ABSTRACT FROM AUTHOR]

Diarrheal irritable bowel syndrome (IBS-D), characterized primarily by the presence of diarrhea and abdominal pain, is a clinical manifestation resulting from a multitude of causative factors. Furthermore, Sishen Wan (SSW) has demonstrated efficacy in treating IBS-D. Nevertheless, its mechanism of action remains unclear. A model of IBS-D was induced by a diet containing 45 % lactose and chronic unpredictable mild stress. Additionally, the impact of SSW was assessed by measuring body weight, visceral sensitivity, defecation parameters, intestinal transport velocity, intestinal neurotransmitter levels, immunohistochemistry, and transmission electron microscopy analysis. Immunofluorescent staining was used to detect the expression of Mucin 2 (MUC2) and Occludin in the colon. Western blotting was used to detect changes in proteins related to tight junction (TJ), autophagy, and endoplasmic reticulum (ER) stress in the colon. Finally, 16S rRNA amplicon sequencing was used to monitor the alteration of gut microbiota after SSW treatment. Our study revealed that SSW administration resulted in reduced visceral sensitivity, improved defecation parameters, decreased intestinal transport velocity, and reduced intestinal permeability in IBS-D mice. Furthermore, SSW promotes the secretion of colonic mucus by enhancing autophagy and inhibiting ER stress. SSW treatment caused remodeling of the gut microbiome by increasing the abundance of Blautia, Muribaculum and Ruminococcus torques group. SSW can improve intestinal barrier function by promoting autophagy and inhibiting ER stress, thus exerting a therapeutic effect on IBS-D. [Display omitted] [ABSTRACT FROM AUTHOR]

Psychological disorders are associated with increased risk of severe inflammatory bowel disease (IBD) by causing gut microbiota dysbiosis and colonic mucosal barrier damage. However, the interaction between chronic restraint stress (CRS), gut microbiota composition, and colonic mucus remains unclear. We demonstrated that mice under CRS conditions exhibited alterations in microbiota composition, disruption of colonic mucus, and aggravation of colitis. In addition, the abundance of Akkermansia muciniphila was significantly decreased in mice under CRS and UC patients with depression, and positively associated with the expression of MUC2. After antibiotic treatment, the recipient mice colonized with CRS microbiota showed barrier defects and severe colitis. Administration of Akkermansia muciniphila was found to restore colonic mucus and modify the gut microbiota. We confirm that CRS-mediated gut microbiota dysbiosis results in colonic mucosal barrier damage and aggravation of colitis. Our results suggest that A. muciniphila is expected to be a potential probiotic to protect and treat colonic mucus that is involved in IBD with psychological disorders. [ABSTRACT FROM AUTHOR]

Psychological disorders are associated with increased risk of severe inflammatory bowel disease (IBD) by causing gut microbiota dysbiosis and colonic mucosal barrier damage. However, the interaction between chronic restraint stress (CRS), gut microbiota composition, and colonic mucus remains unclear. We demonstrated that mice under CRS conditions exhibited alterations in microbiota composition, disruption of colonic mucus, and aggravation of colitis. In addition, the abundance of Akkermansia muciniphila was significantly decreased in mice under CRS and UC patients with depression, and positively associated with the expression of MUC2. After antibiotic treatment, the recipient mice colonized with CRS microbiota showed barrier defects and severe colitis. Administration of Akkermansia muciniphila was found to restore colonic mucus and modify the gut microbiota. We confirm that CRS-mediated gut microbiota dysbiosis results in colonic mucosal barrier damage and aggravation of colitis. Our results suggest that A. muciniphila is expected to be a potential probiotic to protect and treat colonic mucus that is involved in IBD with psychological disorders.

Background: Constipation, mainly characterized by the difficulty in defecation, is a clinical symptom caused by a variety of factors. It can be manifested as normal or slow colonic transport abnormalities, which can occur alone or concurrently with defecation disorders. As there is not uniform definition and assessment standard, no clear plan could be used for the treatment of constipation. Although rhubarb, a traditional Chinese medicine, plays a therapeutic role in diseases involving constipation symptoms, the detailed mechanism of it in treating constipation remains unclear. Methods: A model of constipation-induced by diphenoxylate was prepared. Immunofluorescent staining was used to detect the expression of mucin 2 (MUC2), calnexin and chymase in colon. Western blotting was used to detect changes of tryptase and calnexin in the colon. And real-time polymerase chain reaction (PCR) was utilized to detect the changes of immunoglobulin-binding protein (Bip), X-box binding protein 1 (Xbp1) and C/EBP homologous protein (CHOP) of colonic goblet cells in mRNA levels. ELISA and biochemical kits were utilized to detect the changes of MUC2, Trefoil factor 3 (TFF3), acetylcholine, histamine and C-C motif chemokine ligand 5 (CCL5) in the colon. And the changes of colonic mucosa and intestinal flora of constipation model mice caused by rhubarb extract (RE) were analyzed to identify the mechanism of RE on the treatment of constipation. Results: RE promotes the secretion of colonic mucus by recruiting mast cells and enhancing the content of histamine and Ach in the mice colon. In the process, RE causes up-regulation of Bip and CHOP mRNA expression and down-regulation of Xbp1 and Xbp1s mRNA expression that induces ER stress of colonic epithelium associated with changes in the intestinal flora diversity and short-chain fatty acids content. Conclusion: RE could relieve constipation by promoting the secretion of colonic mucus via mast cells activation and improving the intestinal microenvironment.

Post-weaning diarrheic colitis, often caused by enteropathogens, are severe and potentially lethal diseases in young pigs. Conventional treatment with antibiotics is problematic due to increasing prevalence of multi-drug resistant bacteria. Few alternative treatments exist, so development of antibiotic-free therapies is urgently needed for livestock. Cathelicidin peptides, produced by epithelial cells and neutrophils, are microbicidal compounds capable of modulating innate immune and inflammatory responses. However, the effects of exogenous cathelicidin on gut homeostasis is poorly understood in pigs. We administered the murine cathelicidin CRAMP systemically to healthy pigs, to establish the peptide's safety and assess its ability to modulate colonic mucosal defenses. A single intraperitoneal injection of CRAMP was well tolerated up to two weeks and pigs remained clinically healthy. CRAMP caused some alteration of mucus glycosylation patterns in the colon by increasing sialylated mucins (P < 0.05) and decreased neutrophil influx close to the epithelium (P < 0.001). This study supports further investigation of CRAMP as an immunomodulatory treatment for infectious colitis in pigs. [ABSTRACT FROM AUTHOR]

The colon is subjected to a myriad of potentially damaging agents that may reside within the lumen for 1–2 d. Its first line of defence against these agents is the protective mucus bilayer that lines the entire colonic mucosa. This bilayer acts as a physical barrier to mucosal aggressors and also reduces shear stress to the mucosa. These actions are dependent on the unstimulated (‘resting’) colonic mucus thickness, and also on the rate that this layer can be replenished. The colonic mucus layer is altered in a number of colonic diseases that have been linked to a deficiency of fibre in the diet. The action of fibre intake on colonic mucus thickness and secretion is unknown. Using an in vivo rat model it has been demonstrated that: (1) fibre deficiency leads to a decreased protective potential of the mucus layer (e.g. the mean resting mucus thickness of the fibre-deficient group (429 μm) was significantly lower than its respective control (579 μm; P< 0.001), as was its total mucus secretion over 6 h (270 μm v. 541 μm; P<0.01); (2) specific fibre types in the diet alter the secretion dynamics of colonic mucus (e.g. a cellulose-based diet reduces total mucus secretion over 6 h compared with its control (175 μm v. 463 μm). Analysis of the diets suggested a necessity for both soluble and insoluble fibre types in the diet to increase mucosal protection. [ABSTRACT FROM PUBLISHER]

Colonic mucus is decreased in a rat model of spastic constipation, and some types of water-insoluble dietary fiber increase colonic mucus when consumed by rats for several weeks. However, little is known about the effect of water-soluble dietary fiber on the colonic mucus. The aim of the present study was to investigate the effect of various types of water-soluble dietary fiber on colonic mucus in a rat model of spastic constipation. Oral administration of 1.5 mg/day of carrageenan and chondroitin sulfate increased the fecal excretion, epithelial mucin production, thickness of the mucous layer, and amount of luminal mucus in loperamide-administered rats. Sodium alginate, 5 mg/day, thickened the mucus layer at the fecal surface. Cellulose, 5 mg/day, increased the fecal excretion but not the colonic mucus. Carrageenan, chondroitin sulfate, and sodium alginate, but not cellulose, increased colonic mucus in the rat model of spastic constipation. [ABSTRACT FROM AUTHOR]

Constipation, mainly characterized by the difficulty in defecation, is a clinical symptom caused by a variety of factors. It can be manifested as normal or slow colonic transport abnormalities, which can occur alone or concurrently with defecation disorders. As there is not uniform definition and assessment standard, no clear plan could be used for the treatment of constipation. Although rhubarb, a traditional Chinese medicine, plays a therapeutic role in diseases involving constipation symptoms, the detailed mechanism of it in treating constipation remains unclear. A model of constipation-induced by diphenoxylate was prepared. Immunofluorescent staining was used to detect the expression of mucin 2 (MUC2), calnexin and chymase in colon. Western blotting was used to detect changes of tryptase and calnexin in the colon. And real-time polymerase chain reaction (PCR) was utilized to detect the changes of immunoglobulin-binding protein (Bip), X-box binding protein 1 (Xbp1) and C/EBP homologous protein (CHOP) of colonic goblet cells in mRNA levels. ELISA and biochemical kits were utilized to detect the changes of MUC2, Trefoil factor 3 (TFF3), acetylcholine, histamine and C-C motif chemokine ligand 5 (CCL5) in the colon. And the changes of colonic mucosa and intestinal flora of constipation model mice caused by rhubarb extract (RE) were analyzed to identify the mechanism of RE on the treatment of constipation. RE promotes the secretion of colonic mucus by recruiting mast cells and enhancing the content of histamine and Ach in the mice colon. In the process, RE causes up-regulation of Bip and CHOP mRNA expression and down-regulation of Xbp1 and Xbp1s mRNA expression that induces ER stress of colonic epithelium associated with changes in the intestinal flora diversity and short-chain fatty acids content. RE could relieve constipation by promoting the secretion of colonic mucus via mast cells activation and improving the intestinal microenvironment. Rhubarb extract promotes the secretion of colonic mucus by recruiting mast cells to accumulate in the colon and stimulate the submucosae nervous system to release Ach. In the process, rhubarb extract induces endoplasmic reticulum stress of colonic mucosal goblet cells and causes changes in the intestinal flora and short-chain fatty acids, which improve constipation. [Display omitted] • Rhubarb extract increases mast cells aggregation and goblet cells secretion in colon. • Rhubarb extract induces endoplasmic reticulum stress in colon goblet cells. • Rhubarb extract affects the composition of intestinal microorganisms in mice. • Rhubarb extract improves the intestinal barrier effect through the colonic flora. [ABSTRACT FROM AUTHOR]

The mucosa-associated microbiota is an important component in human microbiota. The aim was to investigate mucosa-associated microbiota using brush samples during endoscopic procedures and compare with fecal microbiota. Seven patients who were planning to undergo a routine colonoscopy were recruited. Mucosal brushing samples were taken from 3 sites (terminal ileum, ascending and sigmoid colon), and a fecal sample was taken on the morning of colonoscopy. The samples were immediately placed in microcentrifuge tubes containing DNA stabilization reagent and analyzed using the next generation sequencer. The individual differences in microbiota were more evident than the differences of the sampling sites. Actinobacteria was more abundant and Bacteroidetes was less in the brush samples than those in the fecal samples. Taxonomic composition at the genus level and the proportion of genes responsible for some functions in the brushing samples tended to be different from those in the fecal samples. Bulleidia and Oribacteriumi were significantly more abundant and the proportions of genes responsible for transcription factors and phosphotransferase system were higher in ileal mucous than those in fecal samples. Brushing during colonoscopic procedure instead of using feces samples might be useful to analyze mucosa-associated microbiota., Competing Interests: The authors have no conflict of interest to declare in this study. Co-authors, YK, SH, KO and MT belong to the Miyarisan Pharmaceutical Co., Ltd., (Copyright © 2019 JCBNCopyright © 2019 JCBN.)