Foldes, G

Harding, SE

Hellen, N

Vittay, O

Cardiovascular Research

Spiral - Imperial College Digital Repository

 Hippo signalling modulates survival of human induced pluripotent stem cell-derived cardiomyocytes Gabor Foldes, Nicola Hellen, Orsolya Vittay, Sian E Harding National Heart and Lung Institute, Imperial College London, London  Background/Introduction: Hippo signalling is an evolutionarily conserved pathway that controls organ size by regulating apoptosis, cell proliferation and stem cell self-renewal. Recently, the pathway has been shown to exert powerful growth regulatory activity in cardiomyocytes. However, functional role of this stress- and cell death-related pathway in human cardiomyocytes is not known.   Purpose: Our aim was to investigate the role of transcriptional Hippo co-activators YAP and TAZ signalling in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM), and to test the effects of modulating the pathway on cardiomyocyte function and survival.  Methods: Human iPSC-CM were plated in different densities or treated with cardiotoxic anthracycline doxorubicin (3-15µM). Gene silencing of YAP and TAZ was achieved by RNAi. The mRNA levels of YAP and TAZ were assessed by real time PCR, and Cellomics ArrayScan was used to quantify YAP/TAZ nuclear translocation and cell death (with Topro3 necrosis marker and mitochondrial membrane potential marker TMRM). CellOPTIQ optical imaging platform was used to measure calcium transients in a high throughput manner.  Results: Our results showed that YAP and TAZ genes are abundantly expressed both in hIPSC-CM and adult ventricular cardiomyocytes. Nuclear translocation and mRNA levels of YAP and TAZ were increased with decreased cell density (for YAP: p<0.001, TAZ: P<0.01, n=3). Other extracellular stress signals such as doxorubicin increased YAP/TAZ translocation (p=0.0004, n=3) and cell loss in a dose-dependent manner in hIPSC-CM. We showed that transient paired downregulation of YAP and TAZ may increase Topro3-positive hIPSC-CM, marking a detrimental effect of their silencing (p=0.0078, n=4). Modulation of YAP/TAZ expression had no effect on hiPSC-CM calcium transient and contractility profiles.  Conclusions: Our results suggest that modulation of Hippo cascade may affect cell viability and necrosis of hIPSC-CM and thereby modulate the survival of human cardiomyocytes.     

Hippo signalling modulates survival of human induced pluripotent stem cell-derived cardiomyocytes

Abstract

Similar works

Full text

Available Versions

Spiral - Imperial College Digital Repository