Wang Wen-Ke, Wang Ben, Cao Xue-Hu, Liu Yu-Sheng
Department of Cardiology, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250033, P.R. China.
Department of General Surgery, Qilu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China.
Exp Ther Med. 2022 Jun;23(6):369. doi: 10.3892/etm.2022.11296. Epub 2022 Apr 5.
Spironolactone improves cardiac structure, function and prognosis in patients with heart failure and delays the progression of cardiac fibrosis. However, the exact underlying mechanism of this process remains to be elucidated. The present study therefore aimed to explore the protective effect and underlying mechanism of the aldosterone receptor antagonist, spironolactone, on myocardial fibrosis in mice with experimental autoimmune myocarditis (EAM). The EAM model was induced in BALB/c mice via immunization with murine cardiac α-myosin heavy chain sequence polypeptides. The cardiac function of the mice was assessed using echocardiography and the levels of inflammatory cytokines were quantified using ELISA. E26 transformation-specific sequence-1 (Ets-1) expression was knocked down using lentivirus-mediated small interference RNA. Total collagen deposition was assessed using Masson's trichrome and Ets-1, TGF-β1, Smad2/3, collagen I and III protein expression levels were detected using immunohistochemistry and western blotting. MMP-2 and MMP-9 mRNA expression levels and activity was determined using reverse transcription-quantitative PCR and gelatin zymography, respectively. The results of the present study demonstrated that spironolactone significantly improved myocardium hypertrophy, diastolic cardiac function and decreased myocardial inflammation and collagen deposition induced by EAM. Spironolactone treatment significantly inhibited Ets-1 and smad2/3 phosphorylation. In addition, inhibition of Ets-1 reduced the expression and activity of MMP-2 and MMP-9 and decreased cardiac fibrosis in EAM mice. The results indicated that the improvement of myocardial fibrosis by spironolactone may be associated with the TGF-β1/Smad-2/3/Ets-1 signaling pathway in EAM mice.
螺内酯可改善心力衰竭患者的心脏结构、功能和预后，并延缓心脏纤维化的进展。然而，这一过程的确切潜在机制仍有待阐明。因此，本研究旨在探讨醛固酮受体拮抗剂螺内酯对实验性自身免疫性心肌炎（EAM）小鼠心肌纤维化的保护作用及其潜在机制。通过用鼠心脏α-肌球蛋白重链序列多肽免疫BALB/c小鼠诱导建立EAM模型。使用超声心动图评估小鼠的心脏功能，并用酶联免疫吸附测定法对炎性细胞因子水平进行定量。使用慢病毒介导的小干扰RNA敲低E26转化特异性序列-1（Ets-1）的表达。采用Masson三色染色法评估总胶原沉积情况，并用免疫组织化学和蛋白质印迹法检测Ets-1、转化生长因子-β1（TGF-β1）、Smad2/3、I型和III型胶原的蛋白表达水平。分别使用逆转录定量聚合酶链反应和明胶酶谱法测定基质金属蛋白酶-2（MMP-2）和基质金属蛋白酶-9（MMP-9）的mRNA表达水平及活性。本研究结果表明，螺内酯可显著改善EAM诱导的心肌肥厚、心脏舒张功能，并减轻心肌炎症和胶原沉积。螺内酯治疗可显著抑制Ets-1和Smad2/3的磷酸化。此外，抑制Ets-1可降低EAM小鼠中MMP-2和MMP-9的表达及活性，并减轻心脏纤维化。结果表明，螺内酯对心肌纤维化的改善作用可能与EAM小鼠中的TGF-β1/Smad-2/3/Ets-1信号通路有关。
