iPSC Modeling of RBM20-Deficient DCM Identifies Upregulation of RBM20 as a Therapeutic Strategy

• Published in: Cell reports (Cambridge) Vol. 32; no. 10; p. 108117
• Main Authors: Briganti, Francesca, Sun, Han, Wei, Wu, Wu, Jingyan, Zhu, Chenchen, Liss, Martin, Karakikes, Ioannis, Rego, Shannon, Cipriano, Andrea, Snyder, Michael, Meder, Benjamin, Xu, Zhenyu, Millat, Gilles, Gotthardt, Michael, Mercola, Mark, Steinmetz, Lars M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 08.09.2020
• Subjects: alternative splicing; cardiomyocytes; DCM; disease modeling; genome editing; iPSC; precision medicine; RBM20; cardiomyocytes; genome editing; alternative splicing; iPSC; disease modeling; RBM20; precision medicine; DCM
• ISSN: 2211-1247; 2211-1247
• DOI: 10.1016/j.celrep.2020.108117

Recent advances in induced pluripotent stem cell (iPSC) technology and directed differentiation of iPSCs into cardiomyocytes (iPSC-CMs) make it possible to model genetic heart disease in vitro. We apply CRISPR/Cas9 genome editing technology to introduce three RBM20 mutations in iPSCs and differentiate them into iPSC-CMs to establish an in vitro model of RBM20 mutant dilated cardiomyopathy (DCM). In iPSC-CMs harboring a known causal RBM20 variant, the splicing of RBM20 target genes, calcium handling, and contractility are impaired consistent with the disease manifestation in patients. A variant (Pro633Leu) identified by exome sequencing of patient genomes displays the same disease phenotypes, thus establishing this variant as disease causing. We find that all-trans retinoic acid upregulates RBM20 expression and reverts the splicing, calcium handling, and contractility defects in iPSC-CMs with different causal RBM20 mutations. These results suggest that pharmacological upregulation of RBM20 expression is a promising therapeutic strategy for DCM patients with a heterozygous mutation in RBM20. [Display omitted] •RBM20 mutant DCM iPSC-cardiomyocytes show mRNA splicing and contractile defects•RBM20 P633L variant causes the phenotypes of the disease•All-trans retinoic acid upregulates RBM20 mRNA and protein expression•Pharmacological RBM20 upregulation ameliorates DCM phenotypes in vitro Briganti et al. use iPSC and CRISPR/Cas9 to create a model of RBM20-deficient dilated cardiomyopathy (DCM) that recapitulates mRNA splicing and contractile defects of the disease. They evaluate pharmacological upregulation of RBM20 as a therapeutic strategy. All-trans retinoic acid upregulates RBM20 expression and ameliorates the in vitro hallmarks of disease.