Document Type

Article

Publication Date

5-4-2021

Publication Title

Cell Rep

Keywords

JGM

JAX Source

Cell Rep 2021 May 4; 35(5):109088

Volume

35

Issue

5

First Page

109088

Last Page

109088

ISSN

2211-1247

PMID

33951429

DOI

https://doi.org/10.1016/j.celrep.2021.109088

Grant

HL12580, EB028898

Abstract

Human cardiac regeneration is limited by low cardiomyocyte replicative rates and progressive polyploidization by unclear mechanisms. To study this process, we engineer a human cardiomyocyte model to track replication and polyploidization using fluorescently tagged cyclin B1 and cardiac troponin T. Using time-lapse imaging, in vitro cardiomyocyte replication patterns recapitulate the progressive mononuclear polyploidization and replicative arrest observed in vivo. Single-cell transcriptomics and chromatin state analyses reveal that polyploidization is preceded by sarcomere assembly, enhanced oxidative metabolism, a DNA damage response, and p53 activation. CRISPR knockout screening reveals p53 as a driver of cell-cycle arrest and polyploidization. Inhibiting sarcomere function, or scavenging ROS, inhibits cell-cycle arrest and polyploidization. Finally, we show that cardiomyocyte engraftment in infarcted rat hearts is enhanced 4-fold by the increased proliferation of troponin-knockout cardiomyocytes. Thus, the sarcomere inhibits cell division through a DNA damage response that can be targeted to improve cardiomyocyte replacement strategies.

Comments

We thank Michael Stitzel (JAX) for his suggestions, the JAX-UConn Single Cell Genomics Center for assistance with scRNA-seq, Anthony Carcio and Tiffany Prosio from the JAX Flow Core for cell sorting, and the University of Washington Garvey Imaging core for assistance with microscopy. Artwork in this study was made, in part, using BioRender.

This is an open access article under the CC BY-NC-ND license

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