高糖激活p38丝裂原活化蛋白激酶信号通路诱导CD8^+T淋巴细胞表达辅助性T淋巴细胞1型趋化因子受体3

CXC-chemokine receptor 3 expression in CD8^+ T cells is activated by high glucose-induced p38 mitogen-activated protein kinase signaling pathway

目的探讨高糖对CD8+T淋巴细胞中辅助性T淋巴细胞(Th)1型趋化因子受体3(CXCR3)表达水平的影响及其可能的机制。方法体外不同浓度葡萄糖(5、10、25、50mmol/L)培养CD8+T淋巴细胞,检测其CXCR3mRNA及蛋白的表达水平变化。同时检测高糖环境下(50mmol/L葡萄糖)CD8+T淋巴细胞氧化应激信号通路相关蛋白P65、P38、细胞外信号调节蛋白激酶(ERK)、c-jun氨基末端激酶(JNK)蛋白表达及磷酸化水平,并观察使用相应抑制剂阻断各氧化应激信号通路对CXCR3mRNA及蛋白表达的影响。结果随着培养基中葡萄糖浓度的升高,5、10、25、50mmol/L葡萄糖处理的CD8+T淋巴细胞中CXCR3mRNA及蛋白表达水平逐渐升高,两两比较,差异均有统计学意义(P值均<0.05),该作用呈浓度依赖性增强。高糖组(50mmol/L葡萄糖)磷酸化的P65、P38、ERK、JNK表达水平均显著高于与正常组(5mmol/L葡萄糖,P值均<0.05)。加入P38信号通路抑制剂SB203580后,高糖环境下CD8+T淋巴细胞的CXCR3mRNA及蛋白的表达水平显著低于高糖组(P值均<0.05),至正常组水平(P值均>0.05);而加入P65信号通路抑制剂BAY11-7082、ERK信号通路抑制剂PD98059、JNK信号通路抑制剂SP600125后,高糖环境下CD8+T淋巴细胞的CXCR3mRNA及蛋白的表达水平仍显著高于正常组(P值均<0.05),与高糖组的差异无统计学意义(P值均>0.05)。结论高糖可能通过激活p38丝裂原活化蛋白激酶(p38MAPK)信号通路诱导CD8+T淋巴细胞表达CXCR3,参与糖尿病周围神经病变发病中CD8+T淋巴细胞的趋化过程。

Objective To investigate the impact of high glucose on the expression of CXC-chemokine receptor 3 （CXCR3） in CD8＋ T cells and its possible mechanism. Methods CD8＋ T cells were cultured with glucose at different concentrations （5, 10, 25 and 50 mmol/L） in vitro. The levels of mRNA and protein of CXCR3 were detected. The activity of oxidative stress signaling pathway of nuclear factor （NF）-κB p65, p38 mitogen- activated protein kinase （MAPK）, extracellular signal-regulated kinase （ERK） and c-jun N-terminal kinase （JNK） in CD8＋ T cells were measured in high glucose （50 mmol/L） environment. And the effect of oxidative stress on the expression of CXCR3 was assessed with the application of corresponding inhibitors. Results High glucose stimulated the expression of mRNA and protein of CXCR3 in CD8＋ T cells in a concentration-dependent way. There were significant differences in the levels of mRNA and protein of CXCR3 between different concentrations of glucose （5, 10, 25 and 50 mmol/L, all P〈0. 05）. The levels of NF-κB p65, p38 MAPK, ERK and JNK in 50 mmol/L glucose culture were significantly higher than those in 5 mmol/L glucose culture （all P〈0.05）. SB203580, the inhibitor of P38 signaling pathway reduced the glucose-induced expression Call P〈0.05）of CXCR3 in CD8＋ Tcells to the normal-glucose level （both P〉0. 05）. But BAY11-7082, PD98059 and SP600125, the inhibitor of P65, ERK and JNK signaling pathway did not reduce the high expression （all P〈0. 05） of CXCR3 in CD8＋ T cells in the environment of high glucose （50 mmol/L）. Conclusion High glucose may induce the expression of CXCR3 by activating p38 MAPK signaling pathway in CD8＋ T cells, which involve in the chemotaxis of CD8＋ T cells in diabetic peripheral neuropathy.