Division of Basic and Translational Cardiovascular Research, Department of Cardiology, Boston Children's Hospital, Boston' MA (A.A.A., M.T., X.L., W.T.P., C.E.B., C.G.B.).
Cardiovascular Research Center, Massachusetts General Hospital, Charlestown' MA (A.A.A., A.S., L.Z., M.M., S.Y., C.N., C.E.B., C.G.B.).
Circ Res. 2022 Dec 2;131(12):980-1000. doi: 10.1161/CIRCRESAHA.122.321728. Epub 2022 Nov 11.
RBPs (RNA-binding proteins) perform indispensable functions in the post-transcriptional regulation of gene expression. Numerous RBPs have been implicated in cardiac development or physiology based on gene knockout studies and the identification of pathogenic RBP gene mutations in monogenic heart disorders. The discovery and characterization of additional RBPs performing indispensable functions in the heart will advance basic and translational cardiovascular research.
We performed a differential expression screen in zebrafish embryos to identify genes enriched in -positive cardiomyocytes or cardiopharyngeal progenitors compared to -negative cells from the same embryos. We investigated the myocardial-enriched gene RNA-binding protein with multiple splicing (variants) 2 [)] by generating and characterizing knockout zebrafish and human cardiomyocytes derived from -deficient induced pluripotent stem cells.
We identified 1848 genes enriched in the -positive population. Among the most highly enriched genes, most with well-established functions in the heart, we discovered the ohnologs and , which encode an evolutionarily conserved RBP. Rbpms2 localizes selectively to cardiomyocytes during zebrafish heart development and strong cardiomyocyte expression persists into adulthood. Rbpms2-deficient embryos suffer from early cardiac dysfunction characterized by reduced ejection fraction. The functional deficit is accompanied by myofibril disarray, altered calcium handling, and differential alternative splicing events in mutant cardiomyocytes. These phenotypes are also observed in RBPMS2-deficient human cardiomyocytes, indicative of conserved molecular and cellular function. RNA-sequencing and comparative analysis of genes mis-spliced in RBPMS2-deficient zebrafish and human cardiomyocytes uncovered a conserved network of 29 ortholog pairs that require for alternative splicing regulation, including , and .
Our study identifies as a conserved regulator of alternative splicing, myofibrillar organization, and calcium handling in zebrafish and human cardiomyocytes.
RBPs（RNA 结合蛋白）在基因表达的转录后调控中发挥着不可或缺的作用。基于基因敲除研究和单基因心脏疾病中致病性 RBP 基因突变的鉴定，许多 RBP 被认为与心脏发育或生理有关。发现和鉴定在心脏中发挥不可或缺作用的其他 RBP 将推进基础和转化心血管研究。
我们在斑马鱼胚胎中进行了差异表达筛选，以鉴定与来自同一胚胎的β-肌球蛋白阴性细胞相比，在β-阳性心肌细胞或心咽祖细胞中富集的基因。我们通过生成和表征 RBPMS2 基因敲除斑马鱼和由 - 缺陷诱导多能干细胞衍生的人类心肌细胞，研究了富含心肌的多剪接基因 RNA 结合蛋白 2（[）。
我们鉴定了 1848 个在β-阳性群体中富集的基因。在最丰富的基因中，大多数在心脏中具有明确的功能，我们发现了同源物 和 ，它们编码一种进化上保守的 RBP。Rbpms2 在斑马鱼心脏发育过程中选择性地定位于心肌细胞，并且强烈的心肌细胞表达持续到成年期。Rbpms2 缺陷胚胎表现出早期心脏功能障碍，表现为射血分数降低。功能缺陷伴随着肌原纤维排列紊乱、钙处理改变以及突变心肌细胞中差异的选择性剪接事件。这些表型也在 RBPMS2 缺陷的人类心肌细胞中观察到，表明具有保守的分子和细胞功能。RNA 测序和比较分析在 RBPMS2 缺陷的斑马鱼和人类心肌细胞中错误剪接的基因，揭示了一个保守的 29 对同源物网络，需要 进行选择性剪接调节，包括 、 和 。
我们的研究鉴定了 作为斑马鱼和人类心肌细胞中选择性剪接、肌原纤维组织和钙处理的保守调节剂。
