白介素17A活化NF-κB p65参与小鼠柯萨奇B3病毒性心肌炎

Involvment of interleukin-17A in the aggravation of coxsackievirus B3-induced viral myocarditis through promoting the activation of nuclear factor-κB p65

目的研究白细胞介素(interleukin,IL)-17A在柯萨奇病毒B3(coxsackievirus B3,CVB3)诱导的小鼠病毒性心肌炎(viral myocarditis,VMC)发病过程中的作用机制。方法以CVB3分别感染Balb/c小鼠野生型(wild-type,WT)和IL-17A基因敲除型(IL-17A-deficient,IL-17A-/-),建立小鼠VMC模型,分别在感染后14d、28d留取心脏称心脏质量,计算心脏指数(heart weight/body weight,HW/BW),行苏木素伊红(HE)染色观察心肌病理改变并计算病理积分,实时荧光定量(real-time polymerase chain reaction,RT-PCR)及酶联免疫吸附测定(ELISA)检测心肌组织中IL-1β、肿瘤坏死因子α(tumor necrosis factor-α,TNT-α)和IL-6 mRNA及蛋白的表达,同时利用免疫印迹分析方法(Western blot)检测心肌组织中核因子(nuclear factor-κB,NF-κB)p65及p-p65的表达。结果与WT小鼠相比,感染CVB3后14 d IL-17A-/-小鼠心肌HW/BW及病理积分减少,心肌的炎症程度明显减轻,心肌组织中IL-1β、TNF-α和IL-6 mRNA及蛋白的表达,NF-κB p-p65蛋白的相对表达均显著低于其在WT小鼠中的表达,差异有统计学意义(P均<0.05);而NF-κB p65蛋白的相对表达在该时点与WT小鼠比较,差异无统计学意义(P>0.05)。结论 IL-17A参与小鼠VMC的致病过程,其机制可能与活化NF-κB p65,诱导炎症介质表达有关。

Objectives To explore the effect of interleukin （IL）-17A on myocardial inflammation in mice with viral myocarditis （VMC）. Methods For establishing VMC models, wild-type （WT） and IL-17A-deficient （IL-17A-/-） mice on the BALB/c background were intraperitoneally （i.p） injected with eoxsaekievirus B3 （CVB3）. On day 14 and day 28 after CVB3 infection, the hearts were weighed to measured the heart index （HW/BW） and the myocardial pathological scores were calculated on hematoxylin and eosin （HE） stained hearts. The expressions of pro-inflammatory cytokines IL-1β, tumor necrosis factor-α （TNF-α） and IL-6 in heart were measured by quantitative real-time polymerase chain reaction （RT-PCR） and enzyme-linked immunosorbent assay （ELISA） separately. Furthermore, the expressions of nuclear factor-KB （NF-KB） p65 and p-p65 were detected by Western blot assay. Results Compared with WT mice, the HW/BW and pathological scores in IL-17A-/- mice were markedly reduced on day 14 after CVB3 infection. The heart of IL-17A-/- mice developed significantly less severe inflammation. The mRNA and protein expressions of cardiac pro-inflammatory cytokines IL-1β, TNF-α and IL-6 in IL-17A-/- mice markedly reduced on day 14 （P〈0.05）. Additionally, the expression of NF-κB p-p65 was significantly suppressed in IL-17A-/- mice on day 14 after CVB3 infection （P〈0.05）, whereas the expression of NF-κB p65 changed little on day 14 （P〉0.05）. Conclusions Our data suggest that IL-17A is crucially involved in the pathogenesis of murine VMC. The mechanisms may be associated with the activation of NF-κB p65 and the expressions of pro-inflammatory mediators.