肌联蛋白（Titin）作为肌小节中的分子弹簧，参与主动、被动张力和回复力的维持与协调，可能是缺血心肌重构过程的关键蛋白。在心肌缺血-再灌注早期，Titin以磷酸化修饰为主。但我们预实验提示，缺血-再灌注后期，Titin异构体比例变化与磷酸化修饰均为缺血心肌重构的基础转变，且与经典的PI3K-Akt及MEK-Erk通路均密切相关；既往文献与我们近期研究均证明，RBM20可以通过pre-mRNA剪切，调控Titin异构体（N2BA与N2B）比例；而预实验提示，RSK4作为Erk下游的重要激酶，可能与RBM20共同作为承上启下的枢纽：1）直接调控Titin磷酸化；2）调控Titin异构体构成；3）协调PI3K-Akt与MEK-Erk之间的交互作用，最终在缺血后心肌重构过程中发挥关键作用。但是，此科学假设的细节亟需更多研究进一步确认，并有望为逆转缺血心肌重构提供更多的理论线索与潜在治疗靶点。

As a molecular spring in the sarcomere, Titin is involved in the maintenance and coordination of active, passive tension and resilience. It is also a key protein in ischemic myocardial remodeling. In the early stage of myocardial ischemia-reperfusion, Titin phosphorylation is the major change. But our pre-experiment proved that in the later stage of reperfusion, Titin isoforms switch and phosphorylation are both contributing to affecting myocardial remodeling. This process may be bound up with PI3K-Akt and MEK-Erk pathways. Previous studies and our recent work have demonstrated that RBM20-dependent pre-mRNA splicing regulates the switch of Titin isoforms (N2BA and N2B), which is closely related to myocardial remodeling. Our pre-experiment suggested that as a core kinase of Erk downstream, RSK4 and RBM20 may take pivotal roles: 1) Directly regulating Titin phosphorylation; 2) Regulating Titin isoforms switch through RBM20; 3) Coordinating the interaction between PI3K-Akt and MEK-Erk. However, it is necessary to confirm the details of this scientific hypothesis with more work. It is also promising to provide potential therapeutic targets for reversing ischemic myocardial remodeling.