ADAMTS-1与小鼠急、慢性病毒性心肌炎心肌纤维化相关性的初步研究

Association between myocardial ADAMTS-1 expression and myocardial fibrosis in a murine model of viral myocarditis

目的检测 ADAMTS-1(a disintegrin and metalloprotease with thrombospondin type 1motifs)在急、慢性柯萨奇病毒 B_3(CVB_3)心肌炎小鼠心肌组织中的表达,并分析其与心肌纤维化的关系。方法以 CVB_3单次感染或重复增量感染 Balb/c 小鼠分别建立急性病毒性心肌炎(n=20)及慢性病毒性心肌炎(n=25)模型,同期小鼠腹腔无菌注射等剂量不含病毒的 EMEM 液作为各自正常对照组(n 均=10)。以苦味酸天狼猩红行心肌胶原组织特异性染色,并运用图像分析软件计算心肌组织中的胶原容积积分(CVF,%)。用逆转录聚合酶链反应(RT-PCR)和免疫组织化学方法分别检测小鼠心肌组织中 ADAMTS-1基因水平和蛋白水平的表达。结果两组病毒性心肌炎小鼠心肌组织中CVF 显著增加,并以慢性组更为显著(P<0.01)。急、慢性病毒性心肌炎组 ADAMTS-1 mRNA 分别比其对照组明显高,尤以慢性组更为显著(P<0.05)。免疫组织化学检测结果显示 ADAMTS-1在心肌组织细胞胞浆内表达,各实验组小鼠心肌组织中 ADAMTS-1 mRNA 的表达与 CVF 呈正相关。结论ADAMTS-1在急、慢性病毒性心肌炎心肌组织中呈进行性增加并与胶原增生密切相关,表明ADAMTS-1可能通过调节胶原代谢参与了心肌纤维化的发生发展。

Objective To investigate the association between myocardial ADAMTS-1 expression and myocardial fibrosis in coxsackievirus B3 （CVB3 ）-induced acute and chronic murine myocarditis model. Methods Balb/c mice were infected with CVB3 （ single injection or monthly injection for 3 months） to establish acute or chronic myocarditis model. Normal controls received equal-volume Eagles minimal essential medium （EMEM） without CVB3. Hearts were examined at 7 days or 3 months post CVB3 infection. Heart slides were stained with collagen specific picrosirius red staining and the collagen volume fraction （CVF） was calculated with image analysis software. The expressions of ADAMTS-1 were determined by RT- PCR and immunohistochemistry. Results Compared with controls, the CVF levels and myocardial expressions of ADAMTS-1 were significant increased in two myocarditis groups, especially in mice with chronic myocarditis （ P 〈 0. 01 ）. The increased expression of ADAMTS-1 was located in endochylema as visualized by immunohistochemistry. Myocardial ADAMTS-1 mRNA was positively correlated with CVF in both myocarditis groups （ r7days, = 0. 65, P 〈 0. 05 ; r3months = 0. 73, P 〈 0. 01 ）. Conclusions ADAMTS-1 increased in proportion with collagen accumulation in acute and chronic myocarditis, which might play an important role in the development of myocardial fibrosis by modulating the collagen metabolism.