OpiA致幽门-胃体移行区粘膜腺体底Lgr5+干细胞发生SPEM的作用及其分子机制研究

There are Lgr5-positive stomach epithelial stem cells at the base of the pyloric glands within the antrum-corpus transitional zone, and this region predispose to the development of SPEM; OpiA is a crucial pathogenic factor that contributes to the occurrence of SPEM within gastric mucosa. But the effect of OpiA on Lgr5+ stem cell abnormal differentiation and its relationship with the development of SPEM remain unknown. This project proposes that OpiA up-regulate Hath1expression, leading to the abnormal differentiation of lgr5+ stem cell, which is the origin of SPEM within this region. We plan to induce SPEM development in mice using OpiA-positive H.pylori, laser microdissection to capture pure normal stem cells at the base of gland and the SPEM cell, detect the expression changes of Hes1,Hath1 and Notch receptors between these two groups cells, thus, to obtain the pathological evidences that Hath1 aberrantly regulate the differentiation of lgr5+ stem cell. We determine to use OpiA lentiviral vector to infect and cytokine IL-8 to stimulate isolated lgr5+ stomach epithelial stem cell, to analyze the influence of OpiA and IL-8 on the differentiation of lgr5+ gastic stem cell in vitro; we plan to detect the change of phosphorylation level of STAT3, and the changes of luciferase activity of Hes1 and Hath1 promoter reporter vectors before and after challenge with OpiA lentiviral vector and cytokine IL-8 in gastric epithelial cell lines, we even plan to screen related regulation factor using EMSA method, eventually to reveal the underlying mechanism of OpiA up-regulate Hath1 expression. This project will provide theoretical support of finding new preventional and therapeutic ways to gastric mucosal epithelia metaplasia.

幽门-胃体移行区胃腺体底部Lgr5+胃上皮干细胞是胃粘膜上皮更新和胃癌发生的始动细胞，痉挛缓解肽表达的化生（SPEM）是胃癌发生的癌前病变，而Lgr5+胃上皮干细胞是如何异常分化为SPEM细胞，是胃癌癌前病变发生的"谜"。基于幽门-胃体移行区胃腺体是SPEM的好发部位，幽门螺杆菌OipA是致SPEM发生的毒力因子及我们前期发现Hp通过IL-8/STAT3/Hes1诱导胃粘膜上皮细胞异常表达Hath1的结果，我们本研究提出OpiA上调Hath1致Lgr5+干细胞异常分化成为SPEM细胞的假设，拟通过分析OipA诱导SPEM模型内正常Lgr5+胃上皮干细胞和SPEM细胞Hes1、Hath1及Notch受体变化以获得其病理学证据；用OipA和IL-8对胃Lgr5+干细胞和胃癌细胞株的分化及其分子机制的研究获得细胞学证据。该研究有利于胃粘膜异常化生的深入认识，为其可能的治疗提供了理想的分子靶位。

幽门-胃体移行区胃腺体底部Lgr5+胃上皮干细胞是胃粘膜上皮更新和胃癌发生的始动细胞，痉挛缓解肽表达的化生（SPEM）是胃癌发生的癌前病变，而Lgr5+胃上皮干细胞是如何异常分化为SPEM细胞，是胃癌癌前病变发生的“谜”。基于幽门-胃体移行区胃腺体是SPEM的好发部位，幽门螺杆菌OipA是致SPEM发生的毒力因子及我们前期发现Hp通过IL-8/STAT3/Hes1诱导胃粘膜上皮细胞异常表达Hath1的结果，在国家自然科学基金的资助下，我们完成了CagA阴性和CagA阳性H.pylori的分离、培养和鉴定，建立了SPEM小鼠模型并完成了该模型的鉴定；在C57BL/6小鼠SPEM模型上检测到了Hes1和Hath1的表达变化；完成了单个Lgr5+胃粘膜干细胞的标记,并通过流式细胞仪分离了Lgr5+胃粘膜干细胞,并成功培养出了Lgr5+胃粘膜干细胞；发现了OpiA阳性幽门螺杆菌可能通过IL-8促使胃上皮细胞的Hath1表达增高，其具体机制可能是在Hath1基因转录水平通过CDX2顺式作用元件发挥作用，这为深入认识胃粘膜化生到异型增生以及胃癌的多步骤演化过程中的分子机制，胃肿瘤的防治提供新的理论支持，具有重要的理论和实践价值。

内容获取失败，请点击重试