Ulcerative colitis(UC) is a lifelong illness with profound emotional and social impacts, and could cause serious damage to large intestine, especially in colon. However, the pathogenesis of UC remained unclear. The present study attempts to find out the role of matrix metalloproteinases-7(MMP-7) and lysozyme in the pathogenesis of UC through a mice model induced by dextran sulfate sodium(DSS). The UC model was evaluated both by disease activity index(DAI) and the intestinal histopathology. The results show that there is a high correlation between the DAI score and the pathological changes of colon. Interleukin-6(IL-6) serum levels and large intestinal fluids levels in UC mice are always higher than that of the control groups, which might be associated with the degree of the inflammation damage in the colon. The change tendency of the MMP-7 mRNA and protein expressions are both up-regulated firstly and then down-regulated from 1 to 5 d in the colon, but only the MMP-7 protein is up-regulated at 7 d again. The up-regulated MMP-7 levels in the early stage of UC may play a protective role through the activated defensins, while the down-regulated levels in the mid-later stage of UC may be connected with the severe lesions in the colon. However, the up-regulated MMP-7 levels in the later stage of UC in the colon may also contribute to the tissue repair or be served as a marker to CRC(colorectal cancer). The distribution of lysozyme protein indicates that there may be Paneth-like cells in the colon. Both the changes of MMP-7 and lysozyme in the small intestine may play a protective role for the safe environment of the whole gut, especially to the colon of UC.
Toll样受体(Toll like receptors,TLRs)是近年发现并倍受关注的一种识别受体。人们发现其在先天性和获得性免疫应答过程中起到链接点的作用,因此,TLRs在免疫学领域内具有重要地位。目前对TLRs的研究涉及到其结构、配体、信号通路以及临床应用等。现就TLRs目前的研究进展作一综述。
