病毒性心肌炎小鼠心肌骨桥蛋白和I 型胶原表达的动态变化

目的:观察病毒性心肌炎(VMC) 小鼠心肌骨桥蛋白(OPN) 及I 型胶原(Col I) 的表达,探讨OPN 在VMC 发病中的作用机制。方法:以 柯萨奇病毒 B3 (myocarditic coxsackievirus B3, CVB3) 感染BALB/C 小鼠建立 VMC 模型,取心肌组织行 HE 和 Masson 染色,并计算病理积分及心肌胶原纤维容积分数(CVF);RT-PCR 检测Col I 含量;RT-PCR及ELISA 法检测OPN 表达。结果:VMC 组第7 天心肌细胞大量坏死,炎性改变明显,随后炎性病灶逐渐吸收,第28 天病灶周围炎细胞几近消失,纤维化明显;VMC 组各时间点心肌病理积分、OPN mRNA 表达均明显高于同时间点对照组(P<0.05),以 第7 天最高,第 14 天开始下降,与 ELISA 检测结果一致;第7, 14 天 Col I mRNA 表达较弱,第21, 28 天表达增强,均高于对照组(P<0.05),与CVF 结果一致,且 Col I mRNA 与CVF 呈正相关。结论:VMC 急性期即出现OPN 表达增加,至恢复期仍高于对照组,提示OPN 可能参与VMC 急性期的炎症反应,并促进恢复期胶原表达。

Dynamic changes between osteopontin and collagen I expression in viral myocarditis mice

Objective: To study the mechanism of osteopontin(OPN) in viral myocarditis by observing the expression of OPN and collagen I(Col I) in mice myocardium.Methods: The viral myocarditis models were achieved by infection with myocarditic coxsackievirus B3(CVB3).The myocardium of mice was stained by HE and Masson staining,and the pathological scores and the collagen volume fraction(CVF)of myocardium were tabulated.The expression of Col I mRNA was measured by RT-PCR.The expression of OPN was detected by RT-PCR and ELISA.Results: The histopathological examination revealed a prevalence of myocardial cell necrosis and obvious inflammation changes at the 7th day post-infection.Subsequently the inflammatory lesions were gradually absorbed.At the 28th day,the in ammatory cells had almost disappeared and obvious fibrosis occurred.The pathological scores and the expression of OPN mRNA were higher than those of the control group(P<0.05),and reached the highest level at the 7th day(P<0.05).From the 14th day,these parameters decreased,reflected also in the ELISA results.At the 7th day and the 14th day,the Col I expression was similar to that of control.Col I expression at the 21th and 28th days was higher than those of the control(P<0.05),and correlated positively to the CVF results.Conclusion: The OPN mRNA expression increased in acute stage of VMC,and higher than that of the control group when in recovery stage,suggesting that OPN might be related to the inflammatory response in acute stage of,and promote the collagen synthesis of recovery stage.