ABSTRACT
Inflammatory bowel disease (IBD) is characterized by recurrent non ⁃ specific intestinal inflammatory responses. Intestinal fibrosis is an important cause of IBD complicated with intestinal obstruction. Nuclear factor erythroid 2⁃ related factor 2 (Nrf2) is a transcription factor that has anti ⁃ oxidative stress response in cells. In IBD, Nrf2 and its downstream regulated antioxidant enzymes achieve protective effects against intestinal fibrosis by inhibiting the activation of nuclear factor ⁃ κB, regulating T helper cell 17/regulatory T cell balance of intestinal immunity, and inhibiting transforming growth factor⁃β1/Smads signaling pathway. In this review, the structure of Nrf2, the specific mechanism of Nrf2's effect on intestinal fibrosis in IBD, and the recent studies on the treatment of IBD through Nrf2 pathway were reviewed in an attempt to provide a new direction for the prevention and treatment of IBD.
ABSTRACT
Aim To investigate the effect of p-hydroxybenzaldehyde ( HD) on intestinal fibrosis in mice based on mouse intestinal fibrosis model and in vitro EMT model,and to explore the underlying mechanism Methods HE staining, Masson staining, immunohisto-chemistry ,qPCR, Western blot and other experimental methods were used to verify the effect of HD on intestinal fibrosis in mice and the potential mechanism. Results In vivo experiments showed that compared with the normal group, the DSS-induced intestinal fibrosis model group had shortened colon, increased colon his-topathological score, increased collagen volume fraction, and significantly increased collagen I expression. After treatment with 4, 10, and 25 mg • kg
ABSTRACT
BACKGROUND:Intestinal fibrosis is a common complication in inflammatory bowel disease and leads to functional damage and intestinal obstruction. Intestinal fibrosis is mainly related to the imbalance of deposition and degradation of extracellular matrix components, such as collagens and fibronectins. Studies have found that mesenchymal stem cells secreted soluble bioactive substance such as extracellular vesicles via paracrine action, which exerted marked anti-fibrosis effect. OBJECTIVE: To investigate the effect of human placenta mesenchymal stem cells-derived extracellular vesicles on collagen deposition in mice with colitis. METHODS: Totally 24 BALB/c mice were randomly divided into sham operation group, model group and extracellular vesicles group, with 8 mice in each group. Except the sham operation group, the remaining mice of model group and extracellular vesicles group were treated with trinitro-benzene-sulfonic acid to induce intestinal fibrosis, once a day for 6 weeks. The mice in the extracellular vesicles group and model group were administered with extracellular vesicles and phosphate-buffered saline, respectively, at 3 weeks, once a day for 6 weeks. The therapeutic effect of extracellular vesicles was evaluated by disease active index score and the colon weight/length ratio at 1-7 weeks. Diseased intestinal segment was subjected to histological staining. Western blot assay and RT-PCR were used to measure fibrosis related indicators so as to evaluate the degree of intestinal fibrosis. RESULTS AND CONCLUSION: (1) Compared with the model group, disease active index score and the colon weight/length ratio were significantly reduced, and colonic pathology was significantly improved in the extracellular vesicles group. (2) Compared with the model group, collagen deposition in colon mucosa of mice was significantly reduced, and the expression of collagen I, collagen III and transforming growth factor-β1 decreased significantly in the extracellular vesicles group. (3) Compared with the model group, expression levels of matrix metalloproteinase 2 and matrix metalloproteinase 9 in mouse colon tissue were significantly increased, while the expression level of tissue inhibitor of metalloproteinase 1 was decreased in the extracellular vesicles group. (4) Results suggest that human placenta mesenchymal stem cells-derived extracellular vesicles can obviously improve the severity of colon injury and reduce the collagen deposition of intestinal mucosa in mice with enteritis.
ABSTRACT
Nuclear factor-erythroid 2 related factor-2 (Nrf2) is the main protective molecule of cells against external pressure with an anti-oxidative stress and anti-inflammatory effect. Inflammatory bowel disease (IBD) is a chronic non-specific intestinal inflammatory disease with a high risk of developing intestinal fibrosis and colorectal cancer. Many studies have confirmed that Nrf2 and its downstream pathway play important roles in IBD intestinal fibrosis and carcinogenesis. Therapeutic drugs targeting Nrf2 signaling pathway are being widely studied. This article reviewed the advances in research on Nrf2 signaling pathway in IBD.
ABSTRACT
Objective To explore the role and mechanism of tumor necrosis factor ligand -related molecule 1A (TL1A) in chronic experimental colitis associated intestinal fibrosis .Methods The model of chronic experimental colitis-associated intestinal fibrosis was induced by dextran sodium sulfate (DSS).The mice with high TL1A (L-Tg) expression in lymphoid cells and wild -type mice with the same genetic background were divided into wild type control group, wild type DSS group, transgenic control group and transgenic DSS group.The changes of body mass, length of colon, disease activity index (DAI) and colonic pathological score were compared among different groups .The degree of colonic inflammation was evaluated by Hematoxylin -Eosin (H-E) staining.The degree of intestinal fibrosis was assessed by Masson staining and Sirius red staining .The expression of vimentin, αsmooth muscle actin ( α-SMA), type Ⅰ collagen, Ⅲ collagen and transforming growth factor-β1 ( TGF-β1 ) /Smad3 in colon tissue was examined by immunohistochemistry .T test was performed for statistical analysis.Results The body mass of the transgenic DSS group decreased by (9.6 ± 1.8)％, which was more than wild-type DSS group (6.2 ±1.3)％, the difference was statistically significant (t =3.751, P <0.01).The DAI score and colonic pathological score of transgenic DSS group were both higher than those of wild-type DSS group (7.33 ±0.58 vs.6.00 ±1.00, and 14.00 ±1.05 vs.11.75 ±0.50, respectively), and the differences were statistically significant (t =2.818 and 4.739, both P <0.05).The results of Masson staining and Sirius red staining showed aggravation of intestinal fibrosis .The results of immunohistochemical staining showed that the cumulative positive absorbance values of vimentin , α-SMA, TGF-β1 and Smad3 of wild-type DSS group were lower than those of transgenic DSS group (0.650 ±0.050 vs. 0.800 ±0.020, 0.390 ±0.040 vs.0.600 ±0.040, 0.550 ±0.040 vs.0.730 ±0.040, 0.590 ±0.020 vs. 0.830 ±0.040), and the differences were statistically significant (t =6.823, 9.093, 7.794 and 10.390, all P <0.01).Conclusion TL1A may promote the proliferation and activation of fibroblasts through TGF -β1 /Smad3 pathway, leading to the genesis and development of experimental colitis associated intestinal fibrosis .
ABSTRACT
Aim To investigate the effect of Ding''s herb enema prescription on intestinal tissue related target in rat colitis induced by dextran sulfate sodium(DSS), and to elucidate the mechanism of Ding''s herb enema prescription in improving the intestinal inflammation and intestinal fibrosis.Methods Rats were fed with 3.5％ DSS.The rats were randomly divided into positive drug group, model group, Control group, and Ding''s herb enema prescription group.The positive drug group was treated with mesalazine enema, and Ding''s herb enema prescription group was treated with Ding''s herb enema prescription.The colon mucosa was taken once a day for 6 weeks.The changes of intestinal inflammatory response and intestinal fibrosis related proteins were detected by GSR-CAA-67 antibody protein array, and the differentially expressed proteins were screened out.Results Eight proteins showed statistical differences, including IFN-γ, erythropoietin(EPO), TIMP-2, TIM-1, IL-6, TIMP-1, TNF-α, IL-22 (P0.05).Conclusions Ding''s herb enema prescription has the effect of multiple targets, which may improve the intestinal inflammatory response and intestinal fibrosis to achieve the purpose of treatment of ulcerative colitis(UC).