Abstract 15916: Role of Small-cajal Body Associated RNAs (scaRNAs) in Regulation of Cardiomyogenesis

Abstract

Introduction: The requirement of non-coding RNAs particularly scaRNAs are playing a critical role in alternative splicing and maturation of mRNAs. Dysregulated splicing of mRNAs has been shown to cause heart defects. In this study, we are comparing the role of scaRNAs during differentiation of induced pluripotent stem cells (iPSCs) into cardiomyocytes (iCMCs) from normal individual and Noonan syndrome (NS) patient. We have selected NS patient cells because it is an autosomal dominant genetic disorder which leads to cardiomyopathy and congenital heart defects in humans. Hypothesis: We hypothesize that scaRNA1 and scaRNA20 have a significant role in the development of cardiomyocytes, and these scaRNAs are dysfunctional in iCMCs derived from NS. Methods and Results: We have compared the normal skin fibroblast-derived iPSCs (N-iPSCs) and N-iCMCs with NS patient-derived NS-iPSCs and NS-iCMCs using quantitative RT-PCR, Western blot and immunofluorescence analyses. We also used the knockdown and overexpression of scaRNA1 and scaRNA20 approaches to delineate the importance of these scaRNAs during cardiomyogenesis. Our qRT-PCR data showed a significantly lower expression of scaRNA1 and scaRNA20 (Fig. A) as well as the cardiac-specific genes CTT and GATA4 (Fig. B) in NS-iCMCs when compared to the normal iCMCs. Furthermore, the qRT-PCR data from the scaRNA20 overexpressed N-iCMC showed an increased expression of cardiac-specific genes (Fig. C) when compared to the N-iCMCs. These studies clearly indicate that scaRNA1 and scaRNA20 plays an important role in cardiomyogenesis. Further studies are underway to explore the mechanisms of these scaRNAs in regulation of cardiac genes. Conclusions: Our findings indicate that scaRNA1 and scaRNA20 are involved in mRNA splicing and maturation of cardiac genes. Moreover, these scaRNAs are dysfunctional in NS patient’s iCMCs and targeting these molecules will have a therapeutic potential for a patient with NS.