炎症相关细胞因子及趋化因子在小鼠自身免疫性肝损伤不同时期的表达及作用

Expression and Function of Inflammatory Cytokines and Chemokines at Different Stages of Autoimmune Liver Injury in Mice

目的研究促炎性细胞因子白介素-6(interleukin-6,IL-6)和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α),抗炎性细胞因子白介素-10(interleukin-10,IL-10),以及趋化因子CXCL10[chemokine(C-X-C motif)ligand 10]在实验性自身免疫性肝炎(autoimmune hepatitis,EAH)小鼠发病期及缓解期肝脏中表达水平差异及相互关系,探讨炎症相关细胞因子及趋化因子在自身免疫性肝损伤中的作用。方法制备EAH模型,设立正常对照组(0周),在建模后发病期(2周)及缓解期(6周)行HE染色观察肝脏病理变化,测定血清ALT及AST水平;实时荧光定量PCR方法检测各组小鼠肝组织IL-6、TNF-α、IL-10和CXCL10的mRNA相对表达水平;ELISA法检测肝组织匀浆中IL-6、TNF-α、IL-10和CXCL10的蛋白表达水平,并行相关性分析。结果肝脏中的促炎性细胞因子IL-6、TNF-α和趋化因子CXCL10在发病期的mRNA和蛋白表达水平均升高(P<0.05),在缓解期IL-6和CXCL10则下降(P<0.05);抗炎性细胞因子IL-10表达水平呈现相似的动态改变,在发病期上升,缓解期下降,但都高于正常水平(P<0.05)。CXCL10与IL-6、TNF-α、IL-10均呈正相关(P<0.05);IL-10与IL-6、TNF-α均呈正相关(P<0.05)。结论促炎性细胞因子IL-6、TNF-α和趋化因子CXCL10主要在发病期高表达促进自身免疫性肝损伤,抗炎性细胞因子IL-10的表达伴随前者动态改变以发挥抗炎作用,3种细胞因子的表达有密切联系。对炎症相关细胞因子和趋化因子进行干预或可缓解自身免疫性肝损伤。

Objective To study the expression and interconnection of proinflammatory cytokines IL-6(interleukin-6)and TNF-α(tumor necrosis factor-α),anti-inflammatory cytokine interleukin IL-10(IL-10),and chemokines CXCL10[chemokine(C-X-C motif)ligand 10]in liver of experimental autoimmune hepatitis(EAH)in the occurrence and the remission period,and discuss the role of inflammatory cytokines and chemokines in autoimmune liver damage.Methods EAH model was prepared and the normal control group(0weeks)was set up.Liver pathological changes were observed by HE staining at the onset(2weeks)and remission(6weeks)after modeling,and serum ALT and AST levels were measured.The mRNA levels of IL-6,TNF-α,IL-10 and CXCL10 in liver tissues of mice in each group were detected by real-time fluorescence quantitative PCR.The protein expression levels of IL-6,TNF-α,IL-10 and CXCL10 in liver homogenate were detected by ELISA,and the correlation between them was analyzed.Results The mRNA and protein expression levels of proinflammatory cytokines IL-6,TNF-αand chemokines CXCL10 in liver were increased in the pathogenesis(P<0.05),and decreased in the remission(P<0.05).The expression level of anti-inflammatory cytokine IL-10 showed a similar dynamic change,which increased in the onset phase and decreased in the remission phase,but both were higher than the normal level(P<0.05).CXCL10 was positively correlated with IL-6,TNF-α,and IL-10(P<0.05).IL-10 was positively correlated with IL-6 and TNF-α(P<0.05).Conclusion Proinflammatory cytokines IL-6,TNF-αand chemokines CXCL10 are mainly highly expressed in the pathogenesis to promote autoimmune liver injury,and the expression of the anti-inflammatory cytokine IL-10 changes dynamically with the former to play an anti-inflammatory role.The expression of the three cytokines is closely related.The intervention of inflammatory cytokines and chemokines may alleviate the autoimmune liver injury.