幽门螺杆菌对结肠炎小鼠的保护作用及可能机制研究

发布时间：2018-04-01 12:37

本文选题：幽门螺杆菌　切入点：溃疡性结肠炎　出处：《南京医科大学》2014年硕士论文

【摘要】：目的：观察幽门螺杆菌(Helicobacter pylori, Hp)感染对葡聚糖硫酸钠(DSS)诱导的急、慢性结肠炎小鼠的影响,并对其可能的免疫机制进行探讨。方法：60只C57BL/6小鼠随机分为6组：正常对照组、Hp感染组(接种H. pyloriSS1菌株)、急性结肠炎组(饮用3%DSS水溶液7天)、慢性结肠炎组(以饮用2%DSS水溶液5天后,改成正常饮水6天为1个周期,循环3个周期)、(Hp+急性结肠炎)组(Hp感染6周后行急性UC造模)、(Hp+慢性结肠炎)组(Hp感染6周后行慢性UC造模)。每日观察各组小鼠的体重变化、粪便性状及便血情况,评估小鼠的疾病活动指数(DAI)。留取小鼠结肠组织,测量长度及评估组织病理损伤。采用ELISA. Real-time PCR方法检测小鼠结肠粘膜组织IFN-γ、 IL-12、TNF-α、IL-6、IL-17、IL-4、IL-10等细胞因子的表达水平。结果：与急性结肠炎组、慢性结肠炎组小鼠相比,(Hp+急性结肠炎)组、(Hp+慢性结肠炎)组小鼠的体重下降程度、腹泻症状及便血情况等临床表现均有明显缓解,且两组小鼠的疾病活动指数(DAI)及组织病理学评分均明显降低(P0.05)。与正常对照组比较,急性结肠炎组、慢性结肠炎组小鼠结肠粘膜组织IFN-γ、TNF-α及IL-6、IL-17表达水平升高(P0.01),慢性结肠炎组小鼠结肠粘膜IL-4表达水平下降；Hp感染后的(Hp+急性结肠炎)组和(Hp+慢性结肠炎)组小鼠下调IFN-γ、TNF-α及IL-6、IL-17的表达(P0.01),上调IL-4表达水平(P0.05),而IL-10表达水平差异无统计学意义。结论：Hp感染能缓解急、慢性结肠炎小鼠的临床症状及减轻结肠病理组织损伤,可能通过调控Th1/Th2/Th17细胞分泌的细胞因子,减轻肠道局部粘膜炎症,从而对UC发挥保护作用。目的：为探讨幽门螺杆菌(Helicobacter pylori, Hp)对溃疡性结肠炎(UC)可能的保护机制,初步观察Hp感染对葡聚糖硫酸钠(DSS)诱导的急、慢性结肠炎小鼠肠道菌群的影响。方法：将60只C57BL/6小鼠随机分为正常对照组、幽门螺杆菌组(接种H. pyloriSS1菌株)、急性结肠炎组(饮用3%DSS水溶液7天)、慢性结肠炎组(以饮用2%DSS水溶液5天后,改成正常饮水6天为1个周期,循环3个周期)、(Hp+急性结肠炎)组(Hp感染6周后行急性UC造模)、(Hp+慢性结肠炎)组(Hp感染6周后行慢性UC造模)。留取小鼠粪便标本、胃粘膜及结肠粘膜组织,应用16SrDNA绝对定量PCR方法检测小鼠肠道拟杆菌属、拟球梭菌属、柔嫩梭菌属、肠杆菌科、类杆菌属、乳酸菌属及幽门螺杆菌的含量。结果：(1)与正常对照组相比,Hp组小鼠胃粘膜仅幽门螺杆菌数量明显增加(P=0.000),余胃粘膜菌群、粪便菌群及结肠粘膜菌群含量未发生明显变化(P0.05)。(2)急性结肠炎组小鼠粪便标本拟杆菌属含量明显下降(P=0.038),肠杆菌科则增加(P=0.049)；结肠粘膜菌群主要为拟杆菌属、肠杆菌科、乳酸菌属含量明显降低(P0.05)；慢性结肠炎组小鼠粪便标本仅肠杆菌科含量增加(P=0.029)；结肠粘膜菌群主要为肠杆菌科、乳酸菌属含量明显升高(P0.05)。(3)(Hp+急性结肠炎)组小鼠结肠粘膜肠杆菌科、乳酸菌属含量较急性结肠炎组小鼠明显增加(P0.05)；(Hp+慢性结肠炎)组小鼠结肠粘膜拟杆菌属、肠杆菌科比慢性结肠炎组小鼠明显降低(P0.05),而乳酸菌属含量无明显变化；而与急、慢性结肠炎组相比,(Hp+急性结肠炎)组、(Hp+慢性结肠炎)组小鼠粪便菌群未发生明显变化(P0.05)。结论：急、慢性结肠炎发生发展与主要粪便菌群和结肠粘膜菌群数量密切相关。Hp感染可能通过调控结肠炎小鼠结肠粘膜菌群变化,而不是粪便菌群,从而影响UC的发生发展。
[Abstract]:Objective : To observe the effect of Helicobacter pylori ( Hp ) infection on acute and chronic colitis mice induced by dextran sulfate ( DSS ) . Methods : 60 C57BL / 6 mice were randomly divided into 6 groups : normal control group , Hp infection group ( 6 weeks after Hp infection ) , acute colitis group ( 3 % DSS aqueous solution 7 days ) , chronic colitis group ( 6 weeks after Hp infection ) . The levels of IFN - 纬 , IL - 12 , TNF - 伪 , IL - 6 , IL - 17 , IL - 4 , IL - 10 and other cytokines in colonic mucosa of mice were significantly lower than those in the control group .
Methods : 60 C57BL / 6 mice were randomly divided into two groups : normal control group , Hp + chronic colitis group , acute colitis group ( 3 % DSS aqueous solution 7 days ) , chronic colitis group ( 6 weeks after Hp infection ) , and no significant difference in IL - 10 expression level ( P = 0.000 ) .
The colonic mucosa flora was mainly the genus Pseudobacterium , Enterobacteriaceae and lactic acid bacteria ( P0.05 ) .
In the chronic colitis group , the intestinal bacilli content increased ( P = 0.029 ) .
There was a significant increase in colonic mucosa flora ( P0.05 ) . ( 3 ) ( 3 ) ( Hp + acute colitis ) group mice were significantly higher than those in acute colitis group ( P0.05 ) .
( P < 0.01 ) . The colonic mucosa of the mice ( Hp + chronic colitis ) group was significantly lower than that in chronic colitis group ( P0.05 ) , but the content of lactic acid bacteria was not changed .
Compared with acute and chronic colitis group ( Hp + acute colitis ) group , there was no significant change in stool flora in mice ( P0.05 ) . Conclusion : The development of acute and chronic colitis is closely related to the number of main fecal flora and colon mucosa . Hp infection may affect the development of UC by regulating the colonic mucosa flora changes of colitis mice rather than fecal flora .

【学位授予单位】：南京医科大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R574.62

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