双环醇介导N6-甲基腺苷甲基化修饰影响大鼠心肌纤维化的作用研究

Effect of bicyclol-mediated N6-methyladenosine methylation on myocardial fibrosis in rats

目的探讨双环醇对心肌纤维化模型大鼠的治疗作用及其可能的作用机制。方法选择无特定病原体级雄性SD大鼠24只,随机分为假手术组、模型组、低剂量组及高剂量组,每组6只。除假手术组外,其他各组尾静脉注射异丙肾上腺素5 mg/(kg·d)建立大鼠心肌纤维化模型,低剂量组、高剂量组分别按照100、200 mg/(kg·d)双环醇进行灌胃治疗,连续给药14 d。采用苏木精-伊红染色分析心肌损伤程度,Masson染色检测心肌纤维化程度,Western blot法检测心肌胶原蛋白Ⅰ、胶原蛋白Ⅲ、α平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)、甲基转移酶样蛋白3(methyltransferase-like protein 3(METTL3))、α-酮戊二酸依赖性双加氧酶ALKB同源物5(α-ketoglutarate-dependent dioxygenase alkB homolog5,ALKBH5)及YTH家族蛋白1(YTH domain family protein 1,YTHDF1)表达。结果与假手术组比较,模型组心肌细胞坏死程度明显升高,心肌纤维化程度增高;与模型组比较,低剂量组、高剂量组心肌细胞破裂和坏死程度明显降低,心肌纤维化程度明显改善。与假手术组比较,模型组心肌组织胶原蛋白Ⅰ、胶原蛋白Ⅲ、α-SMA、METTL3及YTHDF1表达明显升高(P<0.05),模型组ALKBH5表达明显降低(0.58±0.02 vs 0.88±0.07,P<0.05)。与模型组比较,低剂量组、高剂量组心肌组织胶原蛋白Ⅰ、胶原蛋白Ⅲ、α-SMA、METTL3及YTHDF1表达明显降低,ALKBH5表达明显升高,差异有统计学意义(P<0.05)。结论双环醇可有效缓解异丙肾上腺素诱导的心肌纤维化大鼠心肌结构损伤和间质胶原纤维化沉积,其机制可能与m^(6)A甲基化修饰相关。

Objective To explore the therapeutic effect of bicyclol(BIC) on rat model of myocardial fibrosis and its possible mechanism.Methods Twenty-four SPF male SD rats were randomly divided into sham group,model group,low-and high-dose groups,with 6 rats in each group.Except for the sham group,all other groups were injected with 5 mg/(kg·d) isoproterenol by tail vein to establish myocardial fibrosis model,and the low-and high-dose groups were administered by gavage with 100 and 200 mg/(kg·d) BIC,respectively for 14 consecutive days.HE staining and Masson staining were used respectively to observe the severity of myocardial injury and fibrosis.Western blot assay was employed to detect the protein expression of Collagen Ⅰ,Collagen Ⅲ,alpha smooth muscle actin(α-SMA),methyltransferase-like protein 3(METTL3),α-ketoglutarate-dependent dioxygenase AlkB homolog 5(ALKBH5) and YTH domain family protein 1(YTHDF1) in rat myocardium.Results Compared with the sham group,myocardial cell necrosis and myocardial fibrosis were significantly more serious in the model group.Low-and high-dose BIC treatment reduced myocardial cell rupture and necrosis and myocardial fibrosis when compared with the model group.The expression levels of Collagen Ⅰ,Collagen Ⅲ,α-SMA,METTL3 and YTHDF1(P<0.05) were significantly higher,and that of ALKBH5(0.58±0.02 vs 0.88±0.07,P<0.05) was notably lower in the myocardial tissues of the model group than the sham group.While,both doses of BIC treatment significantly reversed above changes in protein levels(P<0.05).Conclusion BIC can effectively alleviate myocardial structural damage and interstitial collagen deposition in rats with isoproterenol-induced myocardial fibrosis,and its mechanism may be related to m~6A methylation modification.