南方医科大学学报 ›› 2018, Vol. 38 ›› Issue (03): 268-.

• • 上一篇    下一篇

p38MAPK信号通路在鼠伤寒沙门菌spvB基因影响Henle-407细胞自噬中的作用

赖华毅,陈强,李红,朱春晖,易丽君,周菁,胡清华,余晓君   

  • 出版日期:2018-03-20 发布日期:2018-03-20

Role of p38MAPK signaling pathway in autophagy of Henle-407 cells induced by spvB of Salmonella typhimurium

  • Online:2018-03-20 Published:2018-03-20

摘要: 目的探讨p38MAPK信号通路在鼠伤寒沙门菌spvB基因影响肠上皮细胞自噬中的作用。方法分别使用携带spvB基因 的鼠伤寒沙门氏菌野生株STM-211、敲除spvB基因的鼠伤寒沙门氏菌突变株STM-ΔspvB和回补株STM-c-spvB与处于生长对 数期的肠黏膜上皮细胞Henle-407细胞进行共培养,并加入p38MAPK通路抑制剂SB203580进行干预。于共培养后的不同时 间点收集细胞,通过免疫印迹法检测p38的磷酸化水平和自噬标志蛋白LC3、P62的表达水平;稀释涂板作胞内细菌计数;免疫 荧光染色观察自噬蛋白LC3的表达及分布。结果共培养后1、2、4 h,STM-211组和STM-c-spvB组p38蛋白的磷酸化水平均低 于STM-ΔspvB组(P<0.05);在共培养后的2 h 和4 h,STM-211 组和STM-c-spvB组胞内活菌计数明显多于STM-ΔspvB组(P< 0.05);在1 h时间点使用SB203580干预后,STM-211组和STM-c-spvB组LC3Ⅱ和P62表达量未见明显改变,而STM-ΔspvB组 LC3Ⅱ表达量降低(P<0.05),P62表达量升高(P<0.05),3 h时该趋势更加明显(P<0.05)。结论鼠伤寒沙门氏菌spvB基因对肠 上皮细胞自噬的抑制作用,可能与其对细胞p38MAPK通路的负调控相关。

Abstract: Objective To investigate the role of p38MAPK signaling pathway in autophagy of intestinal epithelial cells induced by spvB of S.typhimurium. Methods Henle-407 cells in exponential growth were infected with wild-type S.typhimurium strain STM-211 (with spvB gene), spvB mutated strain STM-ΔspvB, or with ΔspvB-complemented strain STM-c-spvB after treatment of the cells with the p38MAPK inhibitor SB203580. At different time points of co- culture, the cells were collected and the intracellular bacteria were counted. Western blotting was performed to detect the expressions of phosphorylated p38 and autophagy-related proteins LC3 and p62; immunofluorescence staining was used to observe the expression and distribution of LC3. Results At 1, 2 and 4 h after the infection, the phosphorylation levels of p38 in STM-211 group and STM-c-spvB group were significantly lower than that in STM-ΔspvB group (P<0.05). At 2 and 4 h of co-culture, the intracellular bacterial counts were significantly greater in STM-211 and STM-c-spvB infection groups than in STM-ΔspvB group (P<0.05). Pretreatment with p38 inhibitor SB203580 did no significantly affect the expression levels of LC3 II or P62 in STM-211 and STM-c-spvB groups, but caused significant reduction in their expressions in STM- ΔspvB group at 1 h (P<0.05), and such changes were more obvious at 3 h (P<0.05). Conclusion The inhibitory effect of spvB gene on autophagy in intestinal epithelial cells is related with the negative regulation of p38MAPK signaling pathway.