敲减突触结合蛋白1通过抑制 IL-6/STAT3信号通路改善结肠炎病变  

Knocking-down Synaptotagmin 1 Attenuated Colitis via Suppressing the IL-6/STAT3 Signaling Pathway

作　　者：石建云 吴晓甜 贺磊 申晶 冯艳林 王德平[1,2] 原一桐 曹济民 SHI Jian-Yun;WU Xiao-Tian;HE Lei;SHEN Jin;FENG Yan-Lin;WANG De-Ping;YUAN Yi-Tong;CAO Ji-Min(Department of Physiology,Shanxi Medical University,Taiyuan 030001,China;Laboratory Animal Center,Shanxi Medical University,Taiyuan 030001,China;Key Laboratory of Cellular Physiology(Shanxi Medical University),Ministry of Education,Taiyuan 030001,China)

机构地区：[1]山西医科大学基础医学院生理学系,太原030001 [2]山西医科大学动物中心,太原030001 [3]山西医科大学细胞生理学教育部重点实验室,太原030001

出　　处：《中国生物化学与分子生物学报》2022年第10期1370-1380,共11页Chinese Journal of Biochemistry and Molecular Biology

基　　金：国家自然科学基金(No.82002063,22007063,82170523);山西省青年科学基金(No.201901D211316);山西医科大学校级博士启动基金(No.XD1809)资助。

摘　　要：突触结合蛋白1 (synaptotagmin 1,Syt1)属于突触结合蛋白家族一员,在神经递质囊泡转运和胞吐中发挥作用。Syt1在肠道上皮中有表达,但其在结肠炎中的生物学功能尚不明确。本工作以Syt1转基因小鼠结合葡聚糖硫酸钠(dextran sodium sulfate,DSS)诱导型溃疡性结肠炎模型,通过qRT-PCR、免疫染色及Western印迹检测Syt1在生理状态及肠炎状态下在结肠中表达的动态变化;采用H&E染色、免疫染色、Western印迹等方法,观察Syt1在结肠炎的炎症反应及肠道上皮再生修复中的作用。结果显示:正常野生小鼠的结肠上皮及结直肠癌患者癌旁组织的肠上皮细胞中均有较高水平的Syt1表达;DSS处理使Syt1在结肠中表达显著升高(P<0.01)。DSS诱导小鼠肠炎模型中,相较于对照组,Syt1敲减小鼠体重降低情况、结肠炎性红肿和长度缩短等均显著减轻(P<0.05),而再生隐窝数量则增多、Ki67增殖细胞也增多(P<0.01);结肠组织中的CD45免疫细胞、F4/80巨噬细胞浸润减少(P<0.001),炎症性肠病相关的促炎因子IL-1β、IL-6和TNFα分泌也减少(P<0.05)。免疫组化及Western印迹结果进一步显示,Syt1敲减小鼠中,IL-6和p-STAT3表达显著下调(P<0.05)。以上研究结果表明,敲减Syt1可能通过抑制IL-6/STAT3信号通路改善结肠炎病变程度。Synaptotagmin 1(Syt1) is a member of the Synaptotagmin family and plays a role in neurotransmitter vesicle transport and exocytosis.It has been reported that Syt1 appears to be expressed in the intestinal epithelium,but the biological function of Syt1 in colitis remains poorly understood.This study aimed to investigate the effects of Syt1 in the inflammatory response and intestinal epithelial regeneration in colitis using Syt1 transgenic mice and dextran sulfate sodium(DSS)-induced ulcerative colitis mode.qRT-PCR and Western blotting were employed to analyze the dynamic changes of Syt1 in colitis.H&E staining,immunostaining and Western blotting were used to explore the roles of Syt1 in the inflammatory response and in the regeneration and repair of intestinal epithelium in colitis.The results showed that the expression level of Syt1 was indeed high in the colonic epithelium of wild-type mice and the intestinal epithelial cells of the adjacent tissues of colorectal cancer patients.Consistently,DSS-induced inflammation progressively resulted in marked upregulation of Syt1 in the colon(P<0.01).In DSS-induced colitis,both the body weight loss and colonic shortening were dampened in Syt1 loss-of-function mice compared with the control group(P<0.05),while the number of regenerated crypts and Ki67 proliferating cells were also increased(P<0.01).Additionally,there were less infiltration of CD45 immune cells and F4/80 macrophages and the expression of pro-inflammatory cytokines IL-6,TNFα and IL1-β,which were related with the severity of inflammation in the inflammatory bowel disease(IBD),were significantly decreased after Syt1 deletion(P<0.05).Immunohistochemistry staining and Western blotting results further showed that IL-6 and p-STAT3 was significantly downregulated in Syt1 knockdown mice(P<0.05).Taken together,these results suggested that knocking-down of Syt1 may improve colitis by inhibiting the IL6/STAT3 signaling pathway.

关 键 词：突触结合蛋白1 结肠炎 炎症反应 上皮再生 IL-6/STAT3信号通路 

分 类 号：R34[医药卫生—基础医学]