薯蓣皂苷对异丙肾上腺素诱导的大鼠心肌纤维化的作用及机制研究

Effects and mechanisms of dioscin on isoproterenol-induced myocardial fibrosis in rats

目的:探究薯蓣皂苷对异丙肾上腺素诱导的大鼠心肌纤维化的抑制作用及可能的机制。方法:24只健康雄性SD大鼠,随机分为对照组、模型组、薯蓣皂苷低剂量(薯蓣皂苷溶液30 mg/kg·d^(-1))、高剂量组(薯蓣皂苷溶液60 mg/kg·d^(-1)),除对照组外,其余各组采用皮下注射异丙肾上腺素(ISO,5 mg/kg·d^(-1)),对照组予以等剂量生理盐水,连续给药10 d,苏木精—伊红染色(HE)及masson染色检测心肌炎症反应和纤维化水平,免疫印迹法(Western blotting)检测核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)、半胱氨酸天冬氨酸蛋白酶-1前体(pro-caspase-1)和半胱氨酸天冬氨酸蛋白酶-1 p20(caspase-1 p20)蛋白表达水平,免疫组化法检测心肌组织胶原蛋白Ⅰ(CollagenⅠ)、胶原蛋白Ⅲ(CollagenⅢ)、白介素-1β(IL-1β)、白介素-18(IL-18)表达水平。结果:与对照组比较,模型组心肌纤维化明显较重,心肌炎症细胞浸润增加,心肌间质CollagenⅠ、CollagenⅢ表达增加,IL-1β、IL-18分泌增加,NLRP3和caspase-1 p20表达升高(P<0.05);与模型组比较,薯蓣皂苷低、高剂量组心肌纤维化有所改善,心肌炎症细胞浸润减少,心肌间质CollagenⅠ、CollagenⅢ表达下降,IL-1β、IL-18分泌减少,NLRP3和caspase-1 p20表达降低(P<0.05)。各组间pro-caspase-1表达量比较,差异无统计学意义(P>0.05)。结论:薯蓣皂苷可通过抑制NLRP3炎症小体表达而改善异丙肾上腺素诱导的大鼠心肌纤维化。

Objective:To investigate the inhibitory effect of dioscin on isoproterenol(ISO)-induced myocardial fibrosis in rats and its possible mechanism.Methods:Twenty-four healthy male Sprague-Dawley(SD)rats were randomly divided into control,model,dioscin low(dioscin solution 30 mg/kg/d),and high dose(dioscin solution 60 mg/kg/d)groups,and all groups except for the control group were treated with subcutaneous injection of ISO(5 mg/kg)for 10 d.The control group rats were given equal volume of saline.Myocardial inflammatory response and fibrosis levels were detected by hematoxylin-eosin(HE)staining and masson staining,and the protein expression levels of nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3),cysteine aspartate protease-1 precursor(pro-caspase 1),and caspase-1 p20 were detected by western blotting,and the expression levels of myocardial interstitial CollagenⅠ,CollagenⅢ,interleukin-1β(IL-1β),and interleukin-18(IL-18)were measured by immunohistochemistry.Results:Compared with the control group,the model group had significantly more myocardial fibrosis,increased myocardial inflammatory cell infiltration,increased myocardial interstitial Collagen I and CollagenⅢexpressions,increased IL-1βand IL-18 secretion,and increased NLRP3 and caspase-1 p20 expressions(P<0.05).Compared with the model group,myocardial fibrosis was improved in the diosgenin low and high dose groups,myocardial inflammatory cell infiltration was reduced,myocardial interstitial CollagenⅠand CollagenⅢexpressions were de-creased,IL-1βand IL-18 secretion was reduced,and NLRP3 and caspase-1 p20 expressions were decreased(P<0.05).The difference in pro-caspase-1 expression was not statistically significant when compared between groups(P>0.05).Conclusion:Dioscin alleviates ISO-induced myocardial fibrosis in rats by inhibiting the expression of NLRP3 inflammatory vesicles.