藏药二十味沉香丸对低氧性肺动脉高压大鼠心肌纤维化的保护作用及机制研究

Study on the Protective Effect and Mechanism of Tibetan Medicine Ershiwei Chenxiang Wan on Myocardial Fibrosis in Rats with Hypoxic Pulmonary Hypertension

关键词:  低氧性肺动脉高压  心肌纤维化  骨桥蛋白

Key words:  hypoxic pulmonary hypertension  myocardial fibrosis  osteopontin

摘要:

目的 探讨藏药二十味沉香丸(Ershiwei Chenxiang Wan, ECW)对低氧性肺动脉高压大鼠心肌纤维化的保护作用及潜在机制。方法 雄性SD大鼠60只，随机分为Control组、HPH组、HPH+0.6 g·kg-1 ECW组、HPH+1.2 g·kg-1 ECW组、HPH+TMZ组，除Control组外，其余各组皮下注射SU5416后，置于低压氧舱三周，每天开舱1 h灌胃给药，记录大鼠体重。实验结束后检测大鼠肺动脉压、右心室压，血细胞计数，血清生化检测NT-proBNP、CK-MB、LDH含量，计算大鼠右心肥厚指数和心脏系数，HE、Masson染色观察心脏组织病理改变及纤维化程度，Western blot 检测大鼠心肌CollagenⅠ、OPN、Akt、pAkt、GSK-3β、pGSK-3β和β-catenin蛋白表达。结果 与对照组比较，HPH组大鼠体重增长缓慢，红细胞增多；肺动脉压、右心室压升高；血清中NT-proBNP、CK-MB、LDH水平升高；心脏质量系数、富尔顿指数增大；心肌出现纤维化，CollagenⅠ表达增多；OPN、pAkt、pGSK-3β和β-catenin表达增加。经ECW干预后，上述异常指标均得到不同程度改善，其中高剂量ECW干预效果更显著。结论 藏药二十味沉香丸可有效缓解低氧性肺动脉高压大鼠心肌损伤，其机制可能与抑制OPN/Akt/GSK-3β信号通路的激活，下调通路相关蛋白表达，进而减轻心肌纤维化进程有关。

Abstract:

OBJECTIVE To investigate the protective effect and potential mechanism of Tibetan medicine Ershiwei Chenxiang Wan (ECW) on myocardial fibrosis in rats with hypoxic pulmonary hypertension(HPH). METHODS Sixty male Sprague-Dawley (SD) rats were randomly divided into five groups:the Control group, HPH group, HPH + 0.6 g·kg?1 ECW group, HPH + 1.2 g·kg?1 ECW group, and HPH + TMZ group. Except for the Control group, rats in the other groups were subcutaneously injected with SU5416, and then placed in a hypobaric oxygen chamber for three weeks, with the chamber opened for 1 hour daily for intragastric administration. The body weight of rats was recorded every day. At the end of the experiment, pulmonary artery pressure (PAP) and right ventricular pressure (RVP) were measured; blood cell count was performed; serum levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), creatine kinase isoenzyme MB (CK-MB) and lactate dehydrogenase (LDH) were detected by serum biochemical assays; the right ventricular hypertrophy index and cardiac index of rats were calculated; hematoxylin-eosin (HE) staining and Masson staining were used to observe the pathological changes and fibrosis degree of cardiac tissues; Western blot was applied to determine the protein expressions of Collagen Ⅰ, osteopontin (OPN), Akt, phosphorylated Akt (pAkt), glycogen synthase kinase-3β (GSK-3β), phosphorylated GSK-3β (pGSK-3β) and β-catenin in myocardial tissues. RESULTS Compared with the Control group, rats in the HPH group showed slowed body weight gain, increased red blood cell count, elevated PAP and RVP, higher serum levels of NT-proBNP, CK-MB and LDH, increased cardiac index and Fulton index, obvious myocardial fibrosis, up-regulated expression of Collagen Ⅰ, as well as increased expressions of OPN, pAkt, pGSK-3β and β-catenin. ECW treatment ameliorated the above indicators, with the high-dose ECW exerting a superior therapeutic effect. CONCLUSION Tibetan medicine ECW can effectively alleviate myocardial injury and improve myocardial fibrosis in HPH rats, and its mechanism may be related to inhibiting the activation of OPN/Akt/GSK-3β signaling pathway, down-regulating the expression of pathway-related proteins, thereby reducing the process of myocardial fibrosis.