Abstract 895: The Role of Poly(rC)-Binding Protein-1 in Heart Development

Abstract

Poly(rC)-Binding Protein-1 (Pcbp1) belongs to the KH homology superfamily of nucleic acid-binding proteins, which has been implicated in a vast array of biological processes such as iron transport, RNA processing, post-transcriptional and translational regulations. Germline deletion of Pcbp1 results in embryonic lethality before embryonic day (E) 8.5. To investigate the role of Pcbp1 in heart development, we generated cardiac-specific conditional deletion of Pcbp1 (Pcbp1-cKO) by crossing the Pcbp1-flox with cTNT-Cre mice. The observed frequencies for Pcbp1-cKO at E12.5 and E16.5 are normal, but no surviving Pcbp1-cKO mice were observed at weaning, suggesting the Pcbp1-cKO is perinatal lethal. E12.5 Pcbp1-cKO hearts are smaller with thin myocardium. At E16.5, Pcbp1 cKO hearts displayed ventricular non-compaction and abnormal ventricular apex formation. To understand molecular mechanisms, we perform RNA sequencing follow by differential gene expression analysis in Pcbp1-cKO hearts at E16.5. We found 241 genes were significantly dysregulated and identified unfolded protein response as a key pathway dysregulated. Furthermore, through alternative splicing analysis, we identified 168 uniquely spliced junctions in 139 genes. Of these, 10 differentially spliced genes are also differentially expressed. Future studies will be performed to better understand the biological function and mechanism of Pcbp1 in the heart. Together, this study suggests Pcbp1 is an important regulator of heart development.