Reduced matrix rigidity promotes neonatal cardiomyocyte dedifferentiation, proliferation and clonal expansion

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Abstract

Cardiomyocyte (CM) maturation in mammals is accompanied by a sharp decline in their proliferative and regenerative potential shortly after birth. In this study, we explored the role of the mechanical properties of the underlying matrix in the regulation of CM maturation. We show that rat and mouse neonatal CMs cultured on rigid surfaces exhibited increased myofibrillar organization, spread morphology, and reduced cell cycle activity. In contrast, compliant elastic matrices induced features of CM dedifferentiation, including disorganized sarcomere network, rounding, and conspicuous cell-cycle re-entry. The rigid matrix facilitated nuclear division (karyokinesis) leading to binucleation, while compliant matrices promoted CM mitotic rounding and cell division (cytokinesis), associated with loss of differentiation markers. Moreover, the compliant matrix potentiated clonal expansion of CMs that involves multiple cell divisions. Thus, the compliant microenvironment facilitates CM dedifferentiation and proliferation via its effect on the organization of the myoskeleton. Our findings may be exploited to design new cardiac regenerative approaches.

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Yfat Yahalom-Ronen

Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel

Competing interests
The authors declare that no competing interests exist.
Dana Rajchman

Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel

Competing interests
The authors declare that no competing interests exist.
Rachel Sarig

Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel

Competing interests
The authors declare that no competing interests exist.
Benjamin Geiger

Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel

Competing interests
The authors declare that no competing interests exist.
Eldad Tzahor

Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel

For correspondence
eldad.tzahor@weizmann.ac.il

Competing interests
The authors declare that no competing interests exist.

Ethics

Animal experimentation: The experiments were approved by the Animal Care and Use Committee of the Weizmann Institute of Science.

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This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.