Xiao Siyu, Liang Rui, Lucero Emilio, McConnell Bradley K, Chen Zhishi, Chang Jiang, Navran Stephen, Schwartz Robert J, Iyer Dinakar
Department of Biology and Biochemistry, University of Houston, Houston, TX 77204, USA.
Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, USA.
J Cardiovasc Aging. 2022 Jul;2(3). doi: 10.20517/jca.2022.20. Epub 2022 Jun 15.
The adult heart lacks the regenerative capacity to self-repair. Serum response factor (SRF) is essential for heart organogenesis, sarcomerogenesis, and contractility. SRF interacts with co-factors, such as NKX2.5 and GATA4, required for cardiac specified gene activity. ETS factors such as ELK1 interact with SRF and drive cell replication. To weaken SRF interactions with NKX2.5 and GATA4, one mutant, SRF153(A3) named STEMIN, did not bind CArG boxes, yet induced stem cell factors such as NANOG and OCT4, cardiomyocyte dedifferentiation, and cell cycle reentry. The mutant YAP5SA of the Hippo pathway also promotes cardiomyocyte proliferation and growth.
Infarcted adult mouse hearts were injected with translatable STEMIN and YAP5SA mmRNA to evaluate their clinical potential.
Mice were pulsed one day later with alpha-EDU and then heart sections were DAPI stained. Replicating cells were identified by immuno-staining against members of the DNA replisome pathway that mark entry to S phase of the cell cycle. Echocardiography was used to determine cardiac function following infarcts and mRNA treatment. To monitor cardiac wall repair, microscopic analysis was performed, and the extent of myocardial fibrosis was analyzed for immune cell infiltration. Injections of STEMIN and YAP5SA mmRNA into the left ventricles of infarcted adult mice promoted a greater than 17-fold increase in the DAPI stained and alpha-EDU marked cardiomyocyte nuclei, within a day. We observed de novo expression of phospho-histone H3, ORC2, MCM2, and CLASPIN. Cardiac function was significantly improved by four weeks post-infarct, and fibrosis and immune cell infiltration were diminished in hearts treated with STEMIN and YAP5SA mmRNA than each alone.
STEMIN and YAP5SA mmRNA improved cardiac function and myocardial fibrosis in left ventricles of infarcted adult mice. The combinatorial use of mmRNA encoding STEMIN and YAP5SA has the potential to become a powerful clinical strategy to treat human heart disease.
成年心脏缺乏自我修复的再生能力。血清反应因子（SRF）对心脏器官发生、肌节发生和收缩性至关重要。SRF与心脏特定基因活性所需的辅助因子相互作用，如NKX2.5和GATA4。ETS因子如ELK1与SRF相互作用并驱动细胞复制。为了削弱SRF与NKX2.5和GATA4的相互作用，一种名为STEMIN的突变体SRF153(A3)不与CArG框结合，但能诱导干细胞因子如NANOG和OCT4、心肌细胞去分化以及细胞周期重新进入。Hippo通路的突变体YAP5SA也能促进心肌细胞增殖和生长。
将可翻译的STEMIN和YAP5SA mRNA注射到梗死的成年小鼠心脏中，以评估它们的临床潜力。
一天后用α-EDU对小鼠进行脉冲处理，然后对心脏切片进行DAPI染色。通过针对标记细胞周期S期进入的DNA复制体途径成员的免疫染色来鉴定复制细胞。使用超声心动图确定梗死和mRNA治疗后的心脏功能。为了监测心脏壁修复情况，进行了显微镜分析，并分析了心肌纤维化程度以检测免疫细胞浸润。将STEMIN和YAP5SA mRNA注射到梗死成年小鼠左心室中，在一天内促进DAPI染色且α-EDU标记的心肌细胞核增加了17倍以上。我们观察到磷酸化组蛋白H3、ORC2、MCM2和CLASPIN的从头表达。梗死四周后心脏功能显著改善，与单独使用STEMIN或YAP5SA mRNA相比，联合使用STEMIN和YAP5SA mRNA治疗的心脏中纤维化和免疫细胞浸润减少。
STEMIN和YAP5SA mRNA改善了梗死成年小鼠左心室的心脏功能和心肌纤维化。编码STEMIN和YAP5SA的mRNA联合使用有可能成为治疗人类心脏病的有力临床策略。
