Multi-Omics Analysis of the Gut-Liver Axis Reveals the Mechanism of Liver Injury in Colitis Mice

Liver injury is a common complication of inflammatory bowel disease (IBD). However, the mechanisms of liver injury development are not clear in IBD patients. Gut microbiota is thought to be engaged in IBD pathogenesis. Here, by an integrated analysis of host transcriptome and colonic microbiome, we have attempted to reveal the mechanism of liver injury in colitis mice. In this study, dextran sulfate sodium (DSS) -induced mice colitis model was constructed. Liver transcriptome showed significant up- and down-regulation of pathways linked to immune response and lipid metabolism, respectively. Whilst the colon transcriptome exhibited dramatic alterations in immune response and pathways associated with cell growth and death. The microbiota of DSS-treated mice underwent strong transitions. Correlation analyses identified genes associated with liver and colon injury, whose expression was associated with the abundance of liver and gut health-related bacteria. Collectively, the results indicate that the liver injury in colitis mice may be related to the intestinal dysbiosis and host-microbiota interactions. These findings may provide new insights for identifying potential targets for the treatment of IBD and its induced liver injury.

Moxibustion Inhibits the Expression of Colonic NLRP3 through miR7/RNF183/NF-κB Signaling Pathway in UC Rats

Background. Moxibustion has been recognized as an effective approach for ulcerative colitis, yet its mechanism is not clear. The research aimed to investigate the influence of moxibustion on the activation of NLRP3 inflammasome and its mechanism in treating ulcerative colitis by observing miR7/RNF183 inducing IκB α ubiquitination to regulate NF-κB signaling pathway in an ulcerative colitis rat model. Methods. An ulcerative colitis rat model was established by unlimited access to self-administration of 3.5% (w/v) dextran sulfate sodium solution. Mild moxibustion was applied to bilateral Tianshu points (ST25) in the moxa-stick moxibustion group; rats in the control group were intervened by intraperitoneal injection of ubiquitination inhibitor, MG132. The disease activity index was determined at the end of the intervention; colon injury was observed and scored after hematoxylin-eosin staining; the immunohistochemical method was adopted to detect the expressions of colonic IL-1β and NLRP3 proteins; Western blot determined the expressions of RNF183, IκB α, and NF-κB p65 proteins in the colon; the immunofluorescence test was used to observe the coexpression of IκB α/ubiquitin and IκB α/RNF183 proteins in the colon; immunoprecipitation assay was adopted to observe the interaction between IκB α and RNF183 proteins; and quantitative real-time polymerase chain reaction determined the expression of colonic miR7. Results. Moxibustion lowered the disease activity index, manifesting as restored colonic tissue and reduced inflammatory reaction, and decreased expression levels of NLRP3 and IL-1β proteins, compared with the model group. It also reduced colonic expression of NF-κB p65 protein, together with the increased level of IκB α protein and weaker expression levels of ubiquitin and RNF183 proteins and mRNAs and stronger expression of miR7. There were no significant differences between the moxa-stick moxibustion group and the control group except the expressions of RNF183 protein and mRNA and miR7. Conclusion. Moxibustion encourages the recovery of colon injury probably by regulating the expression of NLRP3 protein in ulcerative colitis rats through miR7/RNF183/NF-κB signaling pathway.

Silencing of peroxiredoxin 1 expression ameliorates ulcerative colitis in a rat model

Background Peroxiredoxin 1 (PRDX1), a protein with anti-inflammatory and anti-apoptotic properties, shows elevated expression in ulcerative colitis (UC). However, PRDX1's specific role in UC is poorly understood. Methods UC was induced in rats using dextran sulfate sodium (DSS). In vivo RNA interference was used to silence the PRDX1 expression. PRDX1 expression levels and the inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, transforming growth factor (TGF)-β and interferon (IFN)-γ in tissues were assessed by real-time quantitative polymerase chain reaction and western blotting. Colonic injury was assessed by hematoxylin–eosin staining. ELISA was used to assess levels of the inflammatory cytokines TNF-α, IL-1β and IL-6 in colon tissues. Apoptosis of intestinal epithelial cells was assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling, and expression of the apoptotic proteins bcl-2, Bax, cleaved caspase-3 and caspase-3 was assessed by western blotting. Results PRDX1 expression was significantly increased in rats with DSS-induced UC. Silencing of PRDX1 expression improved colon injury in rats with DSS-induced UC. In addition, silencing of PRDX1 expression inhibited inflammatory responses and apoptosis of intestinal epithelial cells in rats with DSS-induced UC. Conclusions Silencing of PRDX1 expression can ameliorate colon injury in rats with DSS-induced UC.

JQ1 as a BRD4 Inhibitor Blocks Inflammatory Pyroptosis-Related Acute Colon Injury Induced by LPS

Endotoxemia is a severe inflammation response induced by infection especially bacterial endotoxin translocation, which severely increases mortality in combination with acute colon injury. Bromodomain-containing protein 4 (BRD4) is an important Bromo and Extra-Terminal (BET) protein to participate in inflammatory responses. However, it is still unknown about the specific connection between BRD4 and inflammation-related pyroptosis in endotoxemia colon. Here, through evaluating the mucous morphology and the expression of tight junction proteins such as occludin and ZO1, we found the upregulation of BRD4 in damaged colon with poor tight junction in an endotoxemia mouse model induced by lipopolysaccharides (LPS). Firstly, the BRD4 inhibitor JQ1 was used to effectively protect colon tight junction in endotoxemia. As detected, high levels of pro-inflammation cytokines IL6, IL1β and IL18 in endotoxemia colon were reversed by JQ1 pretreatment. In addition, JQ1 injection reduced endotoxemia-induced elevation of the phosphorylated NF κB and NLRP3/ASC/caspase 1 inflammasome complex in colon injury. Furthermore, activated pyroptosis markers gasdermins in endotoxemia colon were also blocked by JQ1 pretreatment. Together, our data indicate that BRD4 plays a critical role in regulating pyroptosis-related colon injury induced by LPS, and JQ1 as a BRD4 inhibitors can effectively protect colon from endotoxemia-induced inflammation injury.

Dental pulp stem cells overexpressing hepatocyte growth factor facilitate the repair of DSS-induced ulcerative colitis

Background Ulcerative colitis (UC) is a chronic and recurrent disease without satisfactory treatment strategies. Dental pulp stem cell (DPSC) transplantation has been proposed as a potential therapy for UC. This study aimed to investigate the therapeutic effects of the rat hepatocyte growth factor (HGF) gene transduced into DPSCs for UC. Methods The therapeutic effects of HGF-DPSCs transplanted intravenously into a rat model of UC induced by 5% dextran sulphate sodium (DSS) were compared with the other treatment groups (LV-HGF group, DPSCs group and GFP-DPSCs group). Immunofluorescence and immunohistochemistry were used to observe the localization and proliferation of HGF-DPSCs at the site of colon injury. The expression levels of inflammatory factors were detected by real-time quantitative PCR (RT-PCR) and western blotting. The oxidative stress markers were detected by ELISA. DAI scores and body weight changes were used to macroscopically evaluate the treatment of rats in each group. Results Immunofluorescence and immunohistochemistry assays showed that HGF-DPSCs homed to colon injury sites and colocalized with intestinal stem cell (ISC) markers (Bmi1, Musashi1 and Sox9) and significantly promoted protein expression (Bmi1, Musashi1, Sox9 and PCNA). Anti-inflammatory cytokine (TGF-β and IL-10) expression was the highest in the HGF-DPSCs group compared with the other treatment groups, while the expression of pro-inflammatory cytokines (TNF-α and INF-γ) was the lowest. Additionally, the oxidative stress response results showed that malondialdehyde (MDA) and myeloperoxidase (MPO) expression decreased while superoxide dismutase (SOD) expression increased, especially in the HGF-DPSCs group. The DAI scores showed a downward trend with time in the five treatment groups, whereas body weight increased, and the changes were most prominent in the HGF-DPSCs group. Conclusions The study indicated that HGF-DPSCs can alleviate injuries to the intestinal mucosa by transdifferentiating into ISC-like cells, promoting ISC-like cell proliferation, suppressing inflammatory responses and reducing oxidative stress damage, which provides new ideas for the clinical treatment of UC.

Protective Effect of Daidzein on TNBS Induced Acute Ulcerative Colitis on Rats

The present study aimed at investigating the potential protective effect of Daidzein on 2,4,6-trinitrobenzene sulfonic acid (TNBS) induced acute ulcerative colitis in rats. Animals were treatment with TNBS 20 mg, TNBS dissolved in 50% ethanol by single intra-colonic application into the descending colon, Daidzein 40 and 80 mg/kg per oral, and standard sulfasalazine (SSZ) 360 mg/kg. for Two weeks. Colon was removed, length (CL), weight (CW), microscopic index (MI) processed for histopathological evaluation and estimation of oxidative colon marker contents of active lipid peroxidation (MDA) myeloperoxidase (MPO), reduced glutathione (GSH). Enzymatic activity of superoxide dismutase (SOD) and serum nitrate levels were assessed. TNBS induced significant (p < 0.001), increase in CW, MI, oxidative marker MDA, MPO, and serum nitrate content, TNBS induced a significantly decrease in CL, SOD, and GSH content. Treatment of Daidzein 40 and 80mg with TNBS decreased preserved colon parameter and histology close to normal, increased (P<0.001) SOD, CAT, GSH and TNF- α IL-6 and IL-8 down-regulate the levels to compare SSZ and Daidzein. Daidzein 40and 80mg restored TNBS-induced colon injury via inhibition of oxidative stress. Daidzein found to protect the TNBS Induced Acute Ulcerative Colitis in rats.

Rectal Bleeding after Insertion of a Percutaneous Endoscopic Gastrostomy Tube

Iatrogenic injury to an internal organ such as the stomach, colon, small bowel, or liver after percutaneous endoscopic gastrostomy (PEG) tube insertion is a rare complication. We present a case of rectal bleeding due to colon injury during PEG tube placement. This required urgent exploratory laparoscopic surgery with segmental resection of the transverse colon and replacement of the PEG tube. Postoperatively, the patient significantly improved with time and tolerated PEG tube feeding.