乙氧基血根碱改善血管紧张素Ⅱ诱导的小鼠心肌纤维化的实验研究

Ethoxysanguinarine Alleviates AngiotensinⅡ-induced Cardiac Fibrosis in Mice

目的 探讨乙氧基血根碱对血管紧张素Ⅱ(AngⅡ)诱导的小鼠心肌纤维化的影响及作用机制。方法 构建AngⅡ诱导的高血压小鼠心肌纤维化模型,根据小鼠的基线血压随机分为空白组、模型组、低剂量组、中剂量组、高剂量组、阳性药组。除空白组之外的其余各组小鼠皮下以500 ng/(kg·min)的速率释放AngⅡ,空白组在泵内注入等量体积生理盐水,持续4周;低、中、高剂量组从术后第1天起分别给予0.1、1、10 mg/(kg·d)乙氧基血根碱灌胃,空白组和模型组给予等体积生理盐水,阳性药组给予10 mg/(kg·d)缬沙坦,连续灌胃给药28 d。采用Masson染色及天狼星红染色法检测6组小鼠心肌纤维化及胶原沉积情况;Western blot检测Ⅰ型胶原、Ⅲ型胶原、增殖细胞核抗原(PCNA)、α-平滑肌肌动蛋白(α-SMA)、纤维连接蛋白(FN)及TGF-β1/smad2/3信号通路相关蛋白TGF-β1、p-smad2/3、smad2/3的蛋白表达量。结果 与空白组比较,模型组小鼠心肌细胞出现明显纤维化及胶原沉积,心脏组织中Ⅰ型胶原、Ⅲ型胶原、PCNA、α-SMA及FN的蛋白表达显著增加(P<0.05),通路相关蛋白TGF-β1表达、p-smad2/smad2比值及p-smad3/smad3比值显著上调(P<0.05),而乙氧基血根碱给药后,心肌的纤维化及胶原沉积情况均明显改善,Ⅰ型胶原、Ⅲ型胶原、PCNA、α-SMA、FN、TGF-β1等蛋白表达及p-smad2/smad2和p-smad3/smad3比值均显著下调(P<0.05),且乙氧基血根碱对小鼠心肌纤维化改善的作用呈剂量依赖性(P<0.05)。结论 乙氧基血根碱可改善AngⅡ诱导的心肌纤维化,通过抑制TGF-β/smad2/3通路的活化可能是其发挥作用的机制之一。

Objective:To investigate the effect and mechanism of Ethoxysanguinarine(ETH)on cardiac fibrosis induced by AngiotensinⅡ(AngⅡ)in mice.Methods:Cardiac fibrosis model of hypertensive mice induced by AngⅡwas established.The mice were randomly divided into blank group,model group,ETH-low,ETH-medium and ETH-high groups,positive drug group.ALL the mice except the blank group were injected with AngⅡat a rate of 500 ng/(kg·min)subcutaneously while the blank group was injected with the same volume of normal saline for four weeks.From the first day after surgery,the ETH-low,ETH-medium and ETH-high groups were given 0.1,1,and 10 mg/(kg·d)of ETH by gavage.Respectively,the blank group and the model group were given the same volume of normal saline,and the positive drug group was given 10 mg/(kg·d)of Valsartan.All groups were given drugs by continuous gavage for 28 days.Masson staining and Sirius red staining were used to detect cardiac fibrosis and collagen deposition in mice.The expression of collagen I,collagenⅢ,proliferating cell nuclear antigen(PCNA),α-smooth muscle actin(α-SMA),fibronectin(FN)and TGF-β1/smad2/3 signaling pathway-related proteins TGF-β1,p-smad2,smad2,p-smad3 and smad3 were detected by Western blot.Results:Compared with the blank group,there was significant cardiac fibrosis and collagen deposition in mice cardiomyocytes in the model group,the protein expression of collagen-I,collagenⅢ,PCNA,α-SMA,FN,TGF-β1,p-smad2,smad2,p-smad3 and smad3 ratio in heart tissue were significantly up-regulated(P<0.05),which were significantly reverssed after ETH accompanied with alleviation of cardiac fibrosis and collagen deposition in a dose-dependent manner(P<0.05).Conclusion:ETH can alleviate AngⅡ-induced cardiac fibrosis,the inhibition of TGF-β1/smad2/3 pathway may be one of the important mechanisms.