Reprogramming Human Cardiac Progenitor Cells into Pacemaker Cells for Heart Repair

Abstract

Heart Failure (HF) accounts for 5.7 million deaths annually, which often are the result of acute or chronic ischemic injury due to myocardial infarction (MI). MI is associated with cardiomyocyte death succeeded by scar tissue formation. This scar tissue serves as a mechanical barrier and prevents normal electrical conductivity through the ventricles, thus contributing to the development of arrhythmias. Various stem cell therapies for cardiac repair are directed towards replacing injured myocardium with healthy cardiomyocytes. However, a primary concern with these therapies is their inability to synchronize electromechanically with the recipient myocardium, leading to arrhythmia and aggravating HF symptoms. Our study objective was to use a novel reprogramming strategy to convert human adipogenic mesenchymal stem cells (hADMSCs) first into cardiac progenitor cells (CPCs) and then into conducting Pacemaker‐like cells. Previously, we have shown successful reprogramming of hADMSCs to form CPCs using human transcription factors ETS2 and MESP1. We demonstrated cardiomyocyte phenotype based on gene expression, calcium transients, histology, and polarization wave conduction maps. Interestingly in our current studies, we have optimized a unique cocktail of transcription factors for reprogramming of CPCs into Pacemaker‐like cells using lentiviral vectors. The CPCs treated with transcription factor combinations were initially screened for Pacemaker‐like cells by FACS sorting for mcherry reporter gene specific for pacemaker cells. Following which we assayed these cells for pacemaker marker genes. We observed a robust induction of Pacemaker marker genes, by qPCR gene expression assays. We then validated the functional efficiency of Pacemaker‐like cells in‐vitro through voltage patch clamp recording. Interestingly, the patch clamp recording of the Pacemaker‐like cells exhibited “funny currents” demonstrating the functional characteristic of pacemaker cells. The characteristic of these conduction cells will be further validated by optical mapping in ex‐vivo studies. These studies will facilitate the development of an optimal Pacemaker‐like cell‐based therapy within failing hearts through the recovery of lost contractile and electrical function between cardiomyocytes.Support or Funding InformationThe National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes ofHealth (NIH);Center for the Advancement of Science in Space (CASIS)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.