Human Erbb2-induced Erk activity robustly stimulates cycling and functional remodeling of rat and human cardiomyocytes.

Nicholas Strash,Nenad Bursac,Soon Chul Heo,Geovanni L Janer Carattini,Sophia DeLuca,Ryne Gorsuch

doi:10.7554/elife.65512

Abstract

Multiple mitogenic pathways capable of promoting mammalian cardiomyocyte (CM) proliferation have been identified as potential candidates for functional heart repair following myocardial infarction. However, it is unclear whether the effects of these mitogens are species-specific and how they directly compare in the same cardiac setting. Here, we examined how CM-specific lentiviral expression of various candidate mitogens affects human induced pluripotent stem cell-derived CMs (hiPSC-CMs) and neonatal rat ventricular myocytes (NRVMs) in vitro. In 2D-cultured CMs from both species, and in highly mature 3D-engineered cardiac tissues generated from NRVMs, a constitutively active mutant form of the human gene Erbb2 (cahErbb2) was the most potent tested mitogen. Persistent expression of cahErbb2 induced CM proliferation, sarcomere loss, and remodeling of tissue structure and function, which were attenuated by small molecule inhibitors of Erk signaling. These results suggest transient activation of Erbb2/Erk axis in CMs as a potential strategy for regenerative heart repair.

Highlights

The adult mammalian heart is composed primarily of post-mitotic CMs (Bergmann et al, 2009; Mollova et al, 2013)
We found that the human, but not rat (D'Uva et al, 2015), caErbb[2] ortholog induced the most robust proliferative effects in hiPSC-CMs and neonatal rat ventricular myocytes (NRVMs), which were associated with significant changes in CM morphology and function and mediated via upregulation of the Erk signaling pathway
Because caYap8SA cannot be phosphorylated and degraded, these findings may be explained by the activation of a negative feedback loop that degraded endogenous Yap protein to compensate for caYap8SA overexpression, which in turn attenuated the mitogenic effects in caYap8SA-transduced hiPSC-CMs

Summary

Introduction

The adult mammalian heart is composed primarily of post-mitotic CMs (Bergmann et al, 2009; Mollova et al, 2013). We observed comparable percentages of diploid and polyploid hiPSC-CMs between control and LVtreated total or EdU+ CMs (Figure 1D,E) These results showed that hiPSC-CMs with LVmediated expression of cahErbb[2], caCtnnb[1], and Ccnd[2] were induced to enter DNA synthesis and mitotic phases of the cell cycle at a higher rate than control hiPSC-CMs, and continued to undergo successful cytokinesis. We directly compared the effects of manipulating different mitogenic pathways on in vitro cell cycle activation in CMs from various species and maturation levels, including 2D monolayer cultures of human induced pluripotent stem cell-derived CMs (hiPSC-CMs (Shadrin, 2016; Zhang et al, 2013)) and neonatal rat ventricular myocytes (NRVMs), as well as functional 3D engineered. We found that the human, but not rat (D'Uva et al, 2015), caErbb[2] ortholog (cahErbb2) induced the most robust proliferative effects in hiPSC-CMs and NRVMs, which were associated with significant changes in CM morphology and function and mediated via upregulation of the Erk signaling pathway

Results

Discussion

Methods