纳米α-亚麻酸对病毒性心肌炎小鼠组织蛋白酶B表达的影响

Effect of Nano-α-Linolenic Acid on Expression of Cathepsin B in Mice with Viral Myocarditis

目的探讨纳米α-亚麻酸对病毒性心肌炎(VM)小鼠组织蛋白酶B(CB)表达的作用。方法 80只雄性Balb/c小鼠随机分为4组:对照组、心肌炎组、低剂量干预组及高剂量干预组,每组20只。对照组小鼠腹腔接种病毒培养液,其余3组经腹腔接种柯萨奇病毒B3(CVB3)诱发VM;低剂量干预组、高剂量干预组于病毒接种后当日分别以60 mg.kg-1、180 mg.kg-1纳米α-亚麻酸0.1 mL灌胃,对照组和心肌炎组均以9 g.L-1盐水0.1 mL灌胃,1次.d-1,连续7 d;实验第15天处死全部小鼠,并留取心脏、血清标本,采用HE染色检查各组心肌病理变化,反转录-PCR检测其心肌CB mRNA表达,ELISA测定其血清CB水平。结果对照组、心肌炎组、低剂量干预组、高剂量干预组小鼠死亡率分别为0、45%、30%、20%,高剂量干预组死亡率显著低于心肌炎组(P<0.05),而低剂量干预组与心肌炎组比较差异无统计学意义(P>0.05)。心肌炎组心肌CB mRNA表达水平、血清CB水平均明显高于对照组(Pa<0.01),而低剂量干预组、高剂量干预组CB mRNA表达水平、血清CB水平、心肌病变积分较心肌炎组均显著降低(Pa<0.05,0.01)。结论纳米α-亚麻酸可能通过抑制CB表达,对Balb/c小鼠CVB3心肌炎有良好的治疗作用。

Objective To investigate the effect of nano-α-linolenic acid on the expression of cathepsin B（CB） in mice with viral myocarditis（VM）.Methods Eighty male Balb/c mice were randomly divided into 4 groups：control group,myocarditis group,low-dose intervention group and high-dose intervention group,each group had 20 mice.Mice in control group were inoculated introperitoneally with eagle′s solution,every mouse in the last 3 groups was treated with 0.1 mL Coxsackie B3 virus（CVB3） intraperitoneally.Then,mice in low-dose intervention group and high-dose intervention group were treated with 60 mg·kg^-1and 180 mg·kg^-1 nano-α-linolenic acid solution for 7 days,respectively.Mice in control group and myocarditis group were treated with 9 g·L-1 saline for 7 days.All mice were killed on the 15th day,and the specimens of hearts and serum were conserved.Myocardial histopathology was determined with hematoxylin and eosin stain.The expression levels of myocardial CB mRNA were detected by reverse transcription polymerase chain reaction.Serum CB concentration was examined by enzyme-linked immunosorbent assay.Results The mortality rate was 0,45%,30% and 20% in control group,myocarditis group,low-dose intervention group and high-dose intervention group,respectively;the mortality rate was significantly lower in high-dose intervention group compared with myocarditis group（P0.05）,but there was no difference between low-dose intervention group and myocarditis group（P0.05）.The expression level of CB mRNA and serum CB concentration were markedly higher in myocarditis group than those in control group（Pa0.01）.After nano-α-linolenic acid intervented therapy,CB mRNA and serum CB levels and myocardial histopathological scores were decreased significantly（Pa0.05,0.01）.Conclusion Nano-α-linolenic acid may play a pivotal role in protecting the heart injury by suppressing excessive expression of CB in Balb/c mice with CVB3 myocarditis.