Effects of Huangqin Tang on NLRP3/Caspase-1 pathway in mice model of ulcerative colitis / 中国中药杂志

The aim of this study was to explore the effects of Huangqin Tang(HQT) on the NLRP3/Caspase-1 signaling pathway in mice with DSS-induced ulcerative colitis(UC). C57BL/6J mice were randomly divided into a blank group, a model group(DSS group), and low-, medium-and high-dose HQT groups(HQT-L, HQT-M, and HQT-H), and western medicine mesalazine group(western medicine group). The UC model was induced in mice. Subsequently, the mice in the HQT-L, HQT-M, HQT-H groups, and the western medicine group were given low-, medium-, high-dose HQT, and mesalazine suspension by gavage, respectively, while those in the blank and DSS groups were given an equal volume of distilled water by gavage. After 10 days of administration, the body weight, DAI scores, and colonic histopathological score of mice in each group were determined. The levels of IL-6, IL-10, IL-1β, and TNF-α in serum were determined by ELISA. The mRNA expression of NLRP3 and Caspase-1 in colon tissues was determined by RT-qPCR. The protein expression of NLRP3 and Caspase-1 in colon tissues was detected by immunohistochemistry. The results showed that compared with the blank group, the DSS group showed decreased body weight of mice and increased DAI scores and intestinal histopathological score. Compared with the DSS group, the HQT groups and the western medicine group showed improved DAI scores, especially in the HQT-M, HQT-H, and the western medicine groups(P<0.05). The intestinal histopathological scores of the HQT groups and the western medicine group significantly decreased, especially in the HQT-M, HQT-H, and the western medicine groups(P<0.05). In addition, compared with the blank group, the DSS group showed elevated expression of NLRP3 and Caspase-1 in colon tissues, increased serum levels of IL-6, IL-1β, and TNF-α, and decreased IL-10 level. Compared with the DSS group, the HQT groups and the western medicine group displayed decreased expression of NLRP3 and Caspase-1 in colon tissues, reduced serum levels of IL-6, IL-1β, and TNF-α, and increased IL-10 level. The improvement was the most significant in the HQT-H group and the western medicine group(P<0.01). In conclusion, HQT may reduce the expression of NLRP3 and Caspase-1 in colon tissues, reduce the se-rum levels of IL-6, IL-1β, and TNF-α, and increase the expression of IL-10 by regulating the classic pyroptosis pathway of NLRP3/Caspase-1, thereby improving the symptoms of intestinal injury and inflammatory infiltration of intestinal mucosa in DSS mice to achieve its therapeutic effect.

Therapeutic effect of ursodeoxycholic acid-berberine supramolecular nanoparticles on ulcerative colitis based on supramolecular system induced by weak bond / 中国中药杂志

Ulcerative colitis(UC) is a recurrent, intractable inflammatory bowel disease. Coptidis Rhizoma and Bovis Calculus, serving as heat-clearing and toxin-removing drugs, have long been used in the treatment of UC. Berberine(BBR) and ursodeoxycholic acid(UDCA), the main active components of Coptidis Rhizoma and Bovis Calculus, respectively, were employed to obtain UDCA-BBR supramolecular nanoparticles by stimulated co-decocting process for enhancing the therapeutic effect on UC. As revealed by the characterization of supramolecular nanoparticles by field emission scanning electron microscopy(FE-SEM) and dynamic light scattering(DLS), the supramolecular nanoparticles were tetrahedral nanoparticles with an average particle size of 180 nm. The molecular structure was described by ultraviolet spectroscopy, fluorescence spectroscopy, infrared spectroscopy, high-resolution mass spectrometry, and hydrogen-nuclear magnetic resonance(H-NMR) spectroscopy. The results showed that the formation of the supramolecular nano-particle was attributed to the mutual electrostatic attraction and hydrophobic interaction between BBR and UDCA. Additionally, supramolecular nanoparticles were also characterized by sustained release and pH sensitivity. The acute UC model was induced by dextran sulfate sodium(DSS) in mice. It was found that supramolecular nanoparticles could effectively improve body mass reduction and colon shortening in mice with UC(P<0.001) and decrease disease activity index(DAI)(P<0.01). There were statistically significant differences between the supramolecular nanoparticles group and the mechanical mixture group(P<0.001, P<0.05). Enzyme-linked immunosorbent assay(ELISA) was used to detect the serum levels of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6), and the results showed that supramolecular nanoparticles could reduce serum TNF-α and IL-6 levels(P<0.001) and exhibited an obvious difference with the mechanical mixture group(P<0.01, P<0.05). Flow cytometry indicated that supramolecular nanoparticles could reduce the recruitment of neutrophils in the lamina propria of the colon(P<0.05), which was significantly different from the mechanical mixture group(P<0.05). These findings suggested that as compared with the mechanical mixture, the supramolecular nanoparticles could effectively improve the symptoms of acute UC in mice. The study provides a new research idea for the poor absorption of small molecules and the unsatisfactory therapeutic effect of traditional Chinese medicine and lays a foundation for the research on the nano-drug delivery system of traditional Chinese medicine.

YAP regulates intestinal epithelial cell proliferation through activation of STAT3 in DSS-induced colitis and associated cancer / 中南大学学报(医学版)

OBJECTIVES@#Ulcerative colitis (UC) is a chronic, relapsing inflammation of the colon. Impaired epithelial repair is an important biological features of UC. Accelerating intestinal epithelial repair to achieve endoscopic mucosal healing has become a key goal in UC. Yes-associated protein (YAP) is a key transcriptional coactivator that regulates organ size, tissue growth and tumorigenesis. Growing studies have focused on the role of YAP in intestinal epithelial regeneration. This study explore the molecular mechanism for the role YAP in modulating colonic epithelial proliferation, repair, and the development of colitis associated cancer.@*METHODS@#We constructed the acute colitis mouse model through successive 5 days of 3% dextran sulfate sodium salt (DSS) induction. Then YAP-overexpressed mouse model was constructed by intraperitoneal injection the YAP overexpressed and negative control lentivirus into DSS mice. On the 5th day of DSS induction and the 5th day of normal drinking water after removing DSS (5+5 d), the mice were killed by spinal dislocation. The colon was taken to measure the length, and the bowel 1-2 cm near the anal canal was selected for immunohistochemical and Western blotting. We used YAP over-expressed colonic epithelial cells and small interfering signal transducer and activator of transcription 3 (STAT3) RNA to probe the regulation of YAP on STAT3, using cell counting kit-8 and scratch assays to explore the role of YAP on colonic epithelial cell proliferation. Finally, we conducted co-immunoprecipitation to test the relationship between YAP and STAT3.@*RESULTS@#After DSS treatment, the expression of YAP was dramatically diminished in crypts. Compared with the empty control mice, overexpression of YAP drastically accelerated epithelial regeneration after DSS induced colitis, presenting with more intact of structural integrity in intestinal epithelium and a reduction in the number of inflammatory cells in the mucosa. Further Western blotting, functional experiment and co-immunoprecipitation analyses showed that the expression of YAP in nucleus was significantly increased by 2 h post DSS cessation, accompanied with up-regulated total protein levels of STAT3 and phosphorylated-STAT3 (p-STAT3). Overexpression of YAP enhanced the expression of STAT3, p-STAT3, and their transcriptional targets including c-Myc and Cyclin D1. In addition, it promoted the proliferation and the "wound healing" of colonic cells. However, these effects were reversed when silencing STAT3 on YAP-overexpressed FHC cells. Moreover, protein immunoprecipitation indicated that YAP could directly interact with STAT3 in the nucleus, up-regulatvng the expressvon of STAT3. Finally, during the process of CAC, overexpression of YAP mutant caused the down-regulated expression of STAT3 and inhibited the development and progress of CAC.@*CONCLUSIONS@#YAP activates STAT3 signaling in regulation of epithelial cell proliferation and promotes mucosal regeneration after DSS induced colitis, which may serve as a potential therapeutic target in UC. However, persistent and excessive YAP activation may promote CAC development.

Trichinella spiralis Infection Suppressed Gut Inflammation with CD4+CD25+Foxp3+ T Cell Recruitment

In order to know the effect of pre-existing Trichinella spiralis infection on experimentally induced intestinal inflammation and immune responses, we induced colitis in T. spiralis-infected mice and observed the severity of colitis and the levels of Th1, Th2, and regulatory cytokines and recruitment of CD4+CD25+Foxp3+ T (regulatory T; Treg) cells. Female C57BL/6 mice were infected with 250 muscle larvae; after 4 weeks, induction of experimental colitis was performed using 3% dextran sulfate sodium (DSS). During the induction period, we observed severity of colitis, including weight loss and status of stool, and evaluated the disease activity index (DAI). A significantly low DAI and degree of weight loss were observed in infected mice, compared with uninfected mice. In addition, colon length in infected mice was not contracted, compared with uninfected mice. We also observed a significant increase in production of pro-inflammatory cytokines, IL-6 and IFN-gamma, in spleen lymphocytes treated with DSS; however, such an increase was not observed in infected mice treated with DSS. Of particular interest, production of regulatory cytokines, IL-10 and transforming growth factor (TGF)-beta, in spleen lymphocytes showed a significant increase in mice infected with T. spiralis. A similar result was observed in mesenteric lymph nodes (MLN). Subsets of the population of Treg cells in MLN and spleen showed significant increases in mice infected with T. spiralis. In conclusion, T. spiralis infection can inhibit the DSS-induced colitis in mice by enhancing the regulatory cytokine and Treg cells recruitment.