Rui Huang, Zhao Fang, Yuhua Lei, Hong Jiang
Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.
Cardiovascular Research Institute, Wuhan University, Wuhan, China.
Front Cardiovasc Med. 2023 Mar 2;9:951704. doi: 10.3389/fcvm.2022.951704. eCollection 2022.
Fibrosis of the myocardium is one of the main pathological changes of adverse cardiac remodeling, which is associated with unsatisfactory outcomes in patients with heart disease. Further investigations into the precise molecular mechanisms of cardiac fibrosis are urgently required to seek alternative therapeutic strategies for individuals suffering from heart failure. SMOC2 has been shown to be essential to exert key pathophysiological roles in various physiological processes , possibly contributing to the pathogenesis of fibrosis. A study investigating the relationship between SMOC2 and myocardial fibrosis has yet to be conducted.
Mice received a continuous ISO injection subcutaneously to induce cardiac fibrosis, and down-regulation of SMOC2 was achieved by adeno-associated virus-9 (AAV9)-mediated shRNA knockdown. Neonatal fibroblasts were separated and cultured with TGFβ to trigger fibrosis and infected with either sh-SMOC2 or sh-RNA as a control. The role and mechanisms of SMOC2 in myocardial fibrosis were further examined and analyzed.
SMOC2 knockdown partially reversed cardiac functional impairment and cardiac fibrosis after 21 consecutive days of ISO injection. We further demonstrated that targeting SMOC2 expression effectively slowed down the -differentiation and collagen deposition of cardiac fibroblasts stimulated by TGFβ. Mechanistically, targeting SMOC2 expression inhibited the induction of ILK and p38 and , and ILK overexpression increased p38 phosphorylation activity and compromised the protective effects of sh-SMOC2-mediated cardiac fibrosis.
Therapeutic SMOC2 silencing alleviated cardiac fibrosis through inhibition of the ILK/p38 signaling, providing a preventative and control strategy for cardiac remodeling management in clinical practice.
心肌纤维化是心脏不良重塑的主要病理变化之一,与心脏病患者的不良预后相关。迫切需要进一步研究心脏纤维化的确切分子机制,以寻找针对心力衰竭患者的替代治疗策略。已证明SMOC2在各种生理过程中发挥关键病理生理作用至关重要,可能参与纤维化的发病机制。尚未有研究调查SMOC2与心肌纤维化之间的关系。
小鼠皮下连续注射异丙肾上腺素(ISO)以诱导心脏纤维化,通过腺相关病毒9(AAV9)介导的短发夹RNA(shRNA)敲低实现SMOC2的下调。分离新生大鼠成纤维细胞,用转化生长因子β(TGFβ)培养以引发纤维化,并用sh-SMOC2或作为对照的sh-RNA感染。进一步研究和分析SMOC2在心肌纤维化中的作用及机制。
连续21天注射ISO后,敲低SMOC2可部分逆转心脏功能损害和心脏纤维化。我们进一步证明,靶向SMOC2表达可有效减缓TGFβ刺激的心脏成纤维细胞的分化和胶原蛋白沉积。机制上,靶向SMOC2表达可抑制整合素连接激酶(ILK)和p38的诱导,并且ILK过表达增加p38磷酸化活性并削弱sh-SMOC2介导的心脏纤维化的保护作用。
治疗性沉默SMOC2通过抑制ILK/p38信号通路减轻心脏纤维化,为临床实践中心脏重塑管理提供了预防和控制策略。