Gut microbiota-related bile acid metabolism-FXR/TGR5 axis impacts the response to anti-α4ß7-integrin therapy in humanized mice with colitis.

The gut microbiota and bile acid metabolism are key determinants of the response of inflammatory bowel disease to biologic therapy. However, the molecular mechanisms underlying the interactions between the response to anti-α4ß7-integrin therapy and the gut microbiota and bile acid metabolism remain unknown. In this research, we investigated the role of gut microbiota-related bile acid metabolism on the response to anti-α4ß7-integrin therapy in a humanized immune system mouse model with colitis induced by 2,4,6-trinitrobenzene sulfonic acid. We found that anti-α4ß7-integrin significantly mitigated intestinal inflammation, pathological symptoms, and gut barrier disruption in remission-achieving colitis mice. Whole-genome shotgun metagenomic sequencing demonstrated that employing baseline microbiome profiles to predict remission and the treatment response was a promising strategy. Antibiotic-mediated gut microbiota depletion and fecal microbiome transplantation revealed that the baseline gut microbiota contained common microbes with anti-inflammatory effects and reduced mucosal barrier damage, improving the treatment response. Targeted metabolomics analysis illustrated that bile acids associated with microbial diversity were involved in colitis remission. Furthermore, the activation effects of the microbiome and bile acids on FXR and TGR5 were evaluated in colitis mice and Caco-2 cells. The findings revealed that the production of gastrointestinal bile acids, particularly CDCA and LCA, further directly promoted the stimulation of FXR and TGR5, significantly improving gut barrier function and suppressing the inflammatory process. Taken together, gut microbiota-related bile acid metabolism-FXR/TGR5 axis may be a potential mechanism for impacting the response to anti-α4ß7-integrin in experimental colitis. Thus, our research provides novel insights into the treatment response in inflammatory bowel disease.

Mechanism of annexin A1/N-formylpeptide receptor regulation of macrophage function to inhibit hepatic stellate cell activation through Wnt/ß-catenin pathway.

BACKGROUND: Hepatic fibrosis is a common pathological process of chronic liver diseases with various causes, which can progress to cirrhosis. AIM: To evaluate the effect and mechanism of action annexin (Anx)A1 in liver fibrosis and how this could be targeted therapeutically. METHODS: CCl4 (20%) and active N-terminal peptide of AnxA1 (Ac2-26) and N-formylpeptide receptor antagonist N-Boc-Phe-Leu-Phe-Leu-Phe (Boc2) were injected intraperitoneally to induce liver fibrosis in eight wild-type mice/Anxa1 knockout mice, and to detect expression of inflammatory factors, collagen deposition, and the role of the Wnt/ß-catenin pathway in hepatic fibrosis. RESULTS: Compared with the control group, AnxA1, transforming growth factor (TGF)-ß1, interleukin (IL)-1ß and IL-6 expression in the liver of mice with hepatic fibrosis induced by CCl4 was significantly increased, which promoted collagen deposition and expression of α-smooth muscle actin (α-SMA), collagen type I and connective tissue growth factor (CTGF), and increased progressively with time. CCl4 induced an increase in TGF-ß1, IL-1ß and IL-6 in liver tissue of AnxA1 knockout mice, and the degree of liver inflammation and fibrosis and expression of α-SMA, collagen I and CTGF were significantly increased compared with in wild-type mice. After treatment with Ac2-26, expression of liver inflammatory factors, degree of collagen deposition and expression of a-SMA, collagen I and CTGF were decreased compared with before treatment. Boc2 inhibited the anti-inflammatory and antifibrotic effects of Ac2-26. AnxA1 downregulated expression of the Wnt/ß-catenin pathway in CCl4-induced hepatic fibrosis. In vitro, lipopolysaccharide (LPS) induced hepatocyte and hepatic stellate cell (HSC) expression of AnxA1. Ac2-26 inhibited LPS-induced RAW264.7 cell activation and HSC proliferation, decreased expression of α-SMA, collagen I and CTGF in HSCs, and inhibited expression of the Wnt/ß-catenin pathway after HSC activation. These therapeutic effects were inhibited by Boc2. CONCLUSION: AnxA1 inhibited liver fibrosis in mice, and its mechanism may be related to inhibition of HSC Wnt/ß-catenin pathway activation by targeting formylpeptide receptors to regulate macrophage function.

The Correlation Between MYO9B Gene Polymorphism and Inflammatory Bowel Disease in the Guangxi Zhuang Population.

OBJECTIVE: To analyze the correlation between site rs962917 of the MYO9B gene and inflammatory bowel disease (IBD) in the Guangxi Zhuang nationality population. METHODS: The intestinal mucosa tissue of 153 IBD subjects (Han and Zhuang patients only) in the Guangxi Zhuang autonomous region comprised the case group, and the intestinal mucosa tissue of 155 healthy subjects (Han and Zhuang patients only) in the same region represented the control group. Deoxyribonucleic acid was extracted from the intestinal mucosa tissue of each experimental group, and the MYO9B gene-target fragment containing the single nucleotide polymorphism (SNP) site rs962917 was designed. Finally, polymerase chain reaction products were obtained by amplification, analyzed, and compared using the sequencing results. RESULTS: The results indicated that the genotype frequency of the MYO9B SNP site rs962917 between Crohn's disease (CD) and control groups of Zhuang and Han participants differed significantly (P < 0.05). Furthermore, the genotype frequency of MYO9B site rs962917 differed significantly between the Zhuang and Han population groups (P < 0.05). CONCLUSION: Site rs962917 of the MYO9B gene is related to CD susceptibility and incidence among the Guangxi Zhuang population.

Tnfaip6 Secreted by Bone Marrow-Derived Mesenchymal Stem Cells Attenuates TNBS-Induced Colitis by Modulating Follicular Helper T Cells and Follicular Regulatory T Cells Balance in Mice.

Objective: To investigate the immunological mechanism of bone marrow-derived mesenchymal stem cells (BM-MSCs) in inflammatory bowel disease (IBD). Methods: Mice with 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis were intraperitoneally injected with phosphate-buffered saline, BM-MSCs, BM-MSCs with tumor necrosis factor-induced protein 6 (Tnfaip6) knockdown mediated by RNA interference recombinant adenovirus, and BM-MSCs-infected with control adenovirus or recombinant mouse Tnfaip6. The disease activity index, weight loss, and histological scores were recorded. Serum levels of Tnfaip6 and pro- and anti-inflammatory cytokines, including interleukin (IL)-21, tumor necrosis factor-alpha (TNF-α), IL-10 were measured by enzyme-linked immunosorbent assay. The relative expression levels of these cytokines, B-cell lymphoma 6 (BCL-6) and fork-like transcription factor p3 (Foxp3) in the colon were determined by real-time quantitative PCR (RT-qPCR). BCL-6 and Foxp3 are the master regulators of follicular helper T cells (Tfh) and follicular regulatory T cells (Tfr), respectively. The infiltration of Tfh and Tfr in mesenteric lymph nodes (MLNs) and spleens was analyzed by flow cytometry. Results: Compared to the normal control group, the expression levels of BCL-6 and IL-21 in the colon, Tfh infiltration, and ratios of Tfh/Tfr in the MLNs and spleen, and the serum concentrations of IL-21 and TNF-α increased significantly in the colitis model group (p < 0.05). Intraperitoneal injection of BM-MSCs or Tnfaip6 ameliorated weight loss and clinical and histological severity of colitis, downregulated the expression of BCL-6, IL-21, and TNF-α, upregulated the expression of Foxp3, IL-10, and Tnfaip6 (p < 0.05), increased Tfr and reduced the infiltration of Tfh in the MLNs and spleen, and downregulated the Tfh/Tfr ratio (p < 0.05). On the other hand, BM-MSCs lost the therapeutic effect and immune regulatory functions on Tfh and Tfr after Tnfaip6 knockdown. Conclusion: Tfh increase in the inflamed colon, Tfh decrease and Tfr increase during the colitis remission phase, and the imbalance of the Tfh/Tfr ratio is closely related to the progression of IBD. Tnfaip6 secreted by BM-MSCs alleviates IBD by inhibiting Tfh differentiation, promoting Tfr differentiation, and improving the imbalance of Tfh/Tfr in mice.

Pathogenesis of autoimmune hepatitis.

Autoimmune hepatitis (AIH) is a chronic progressive liver disease whose etiology and pathogenesis are not yet clear. It is currently believed that the occurrence of AIH is closely related to genetic susceptibility and immune abnormalities, and other factors such as environment, viral infection and drugs that may cause immune dysfunction. This article reviews the pathogenesis of AIH and describes the latest research results in the past 5 years.

Infliximab is effective in the treatment of ulcerative colitis with dermatomyositis: A case report.

BACKGROUND: Joint, skin, oral cavity, and eye lesions are the most common extraintestinal manifestations of ulcerative colitis that can occur before or after its onset. The cases of ulcerative colitis with dermatomyositis (DM) are rare. In this study, we report a rare case of ulcerative colitis with DM that was effectively treated with infliximab. CASE SUMMARY: The patient was a 57-year-old female with a 2-year history of DM. The patient was admitted to hospital with abdominal pain, diarrhea, and blood in stool lasting for more than 2 mo. Colonoscopy revealed multiple erosions and ulcers in the entire colon and rectum. Pathological sections showed chronic inflammatory cell infiltration, especially neutrophil infiltration, in the colonic mucosa; therefore, the patient was diagnosed with ulcerative colitis. Preparations of 5-aminosalicylic acid was added to her treatment based on the original treatment for DM, but its effect was unsatisfactory. The patient's discomfort was relieved after infliximab treatment. CONCLUSION: Infliximab can improve DM in the treatment of ulcerative colitis. Specialists need to raise awareness about patients with inflammatory bowel disease who have rare extraintestinal manifestations.

Berberine protects myocardial cells against anoxia-reoxygenation injury via p38 MAPK-mediated NF-κB signaling pathways.

Ischemic heart disease is a leading cause of mortality and occurs due to coronary arterial atherosclerosis, vascular cavity stenosis and occlusion. It has previously been demonstrated that berberine treatment may ameliorate and help to prevent cardiovascular diseases due to its anti-inflammatory and anti-apoptotic effects in myocardial cells. However, the potential signaling mechanisms mediated by berberine in the progression of myocardial injury remain to be elucidated. The aim of the present study was to investigate the therapeutic effects of berberine and its potential mechanism in a mouse model of myocardial cell injury. The results revealed that berberine treatment downregulated the serum expression of inflammatory factors, including interleukin (IL)-6, tumor necrosis factor-α, IL-10 and IL-17A in mice with anoxia-reoxygenation injury. Berberine treatment also decreased myocardial cell apoptosis following anoxia-reoxygenation injury via regulating the expression of apoptosis-associated genes. Histological analysis revealed that the area, circumference fragmentation and segmentation of myocardial cells were significantly decreased by berberine treatment compared with the control group. The body weight, blood lipid levels, blood pressure and heart rate were markedly improved in mice with anoxia-reoxygenation injury following berberine treatment compared with untreated mice. The expression of p38 mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB expression was downregulated in myocardial cells from in mice with anoxia-reoxygenation injury following berberine treatment compared with untreated mice. However, p38 MAPK overexpression ameliorated the berberine-induced decrease in NF-κB activity and expression, as well as the berberine-induced inhibition of myocardial apoptosis in myocardial cells isolated from experimental mice. In conclusion, the results of the present study indicate that berberine is able to decrease the expression of inflammatory cytokines expression and inhibit myocardial cell apoptosis via downregulating the p38 MAPK-mediated NF-κB signaling pathway. These results suggest that berberine may be an effective treatment for anoxia-reoxygenation injury.

Cell adhesion molecule pathway genes are regulated by cis-regulatory SNPs and show significantly altered expression in Alzheimer's disease brains.

We previously identified the cell adhesion molecule (CAM) pathway as a consistent signal in 2 Alzheimer's disease (AD) genome-wide association studies (GWAS). However, the genetic mechanisms of the CAM pathway in AD are unclear. Here, we conducted pathway analysis using (1) Kyoto Encyclopedia of Genes and Genomes and Gene Ontology pathways; (2) 4 brain expression GWAS datasets; and (3) 2 whole-genome AD case-control expression datasets. Using the 4 brain expression GWAS datasets, we identified that genes regulated by cis-regulatory single-nucleotide polymorphisms (SNPs) were significantly enriched in the CAM pathway (p = 2.05E-06, p = 6.10E-07, p = 2.05E-06, and p = 1.47E-07 for each dataset). Interestingly, CAM is a significantly enriched pathway using down-regulated genes (raw p = 0.0235 and adjusted p = 0.0305) and all differentially expressed genes (raw p = 0.0105 and adjusted p = 0.0156) in dataset 5, and all differentially expressed genes (raw p = 0.0041 and adjusted p = 0.0062) in dataset 6. Collectively, our results show that CAM pathway genes are regulated by cis-regulatory SNPs and show significantly altered expression in AD. We believe that our results advance the understanding of AD mechanisms and will be useful for future genetic studies of AD.