Related Experiment Video
Updated: Apr 19, 2026
Generation and Expansion of Human Cardiomyocytes from Patient Peripheral Blood Mononuclear Cells
Published on: February 12, 2021
Extracardiac control of embryonic cardiomyocyte proliferation and ventricular wall expansion
Hua Shen1, Susana Cavallero1, Kristine D Estrada1
1Broad Center for Regenerative Medicine and Stem Cell Research, University of Southern California, 1425 San Pablo Street, BCC-511, Los Angeles, CA 90033, USA.
Aims:
The strategies that control formation of the ventricular wall during heart development are not well understood. In previous studies, we documented IGF2 as a major mitogenic signal that controls ventricular cardiomyocyte proliferation and chamber wall expansion. Our objective in this study was to define the tissue source of IGF2 in heart development and the upstream pathways that control its expression.
Methods And Results:
Using a number of mouse genetic tools, we confirm that the critical source of IGF2 is the epicardium. We find that epicardial Igf2 expression is controlled in a biphasic manner, first induced by erythropoietin and then regulated by oxygen and glucose with onset of placental function. Both processes are independently controlled by retinoic acid signalling.
Conclusions:
Our results demonstrate that ventricular wall cardiomyocyte proliferation is subdivided into distinct regulatory phases. Each involves instructive cues that originate outside the heart and thereby act on the epicardium in an endocrine manner, a mode of regulation that is mostly unknown in embryogenesis.
