Intermittent Starvation Promotes Maturation of Human Embryonic Stem Cell-Derived Cardiomyocytes

Jingsi Yang; Nan Ding; Dandan Zhao; Yunsheng Yu; Chunlai Shao; Xuan Ni; Zhen-Ao Zhao; Zhen Li; Jianquan Chen; Zheng Ying; Miao Yu; Wei Lei; Shijun Hu

doi:10.3389/fcell.2021.687769

Intermittent Starvation Promotes Maturation of Human Embryonic Stem Cell-Derived Cardiomyocytes

Front Cell Dev Biol. 2021 Jul 30:9:687769. doi: 10.3389/fcell.2021.687769. eCollection 2021.

Authors

Jingsi Yang¹, Nan Ding¹, Dandan Zhao¹, Yunsheng Yu¹, Chunlai Shao², Xuan Ni¹, Zhen-Ao Zhao³, Zhen Li⁴, Jianquan Chen⁵, Zheng Ying⁶, Miao Yu¹, Wei Lei¹, Shijun Hu¹

Affiliations

¹ Department of Cardiovascular Surgery of the First Affiliated Hospital & Institute for Cardiovascular Science, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Protection, Medical College, Soochow University, Suzhou, China.
² Department of Cardiology, The Second Affiliated Hospital of Soochow University, Suzhou, China.
³ Institute of Microcirculation & Department of Pathophysiology of Basic Medical College, Hebei North University, Zhangjiakou, China.
⁴ Center for Molecular Imaging and Nuclear Medicine, State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, China.
⁵ Orthopedic Institute, Medical College, Soochow University, Suzhou, China.
⁶ Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, China.

Abstract

Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) represent an infinite cell source for cardiovascular disease modeling, drug screening and cell therapy. Despite extensive efforts, current approaches have failed to generate hPSC-CMs with fully adult-like phenotypes in vitro, and the immature properties of hPSC-CMs in structure, metabolism and electrophysiology have long been impeding their basic and clinical applications. The prenatal-to-postnatal transition, accompanied by severe nutrient starvation and autophagosome formation in the heart, is believed to be a critical window for cardiomyocyte maturation. In this study, we developed a new strategy, mimicking the in vivo starvation event by Earle's balanced salt solution (EBSS) treatment, to promote hPSC-CM maturation in vitro. We found that EBSS-induced starvation obviously activated autophagy and mitophagy in human embryonic stem cell-derived cardiomyocytes (hESC-CMs). Intermittent starvation, via 2-h EBSS treatment per day for 10 days, significantly promoted the structural, metabolic and electrophysiological maturation of hESC-CMs. Structurally, the EBSS-treated hESC-CMs showed a larger cell size, more organized contractile cytoskeleton, higher ratio of multinucleation, and significantly increased expression of structure makers of cardiomyocytes. Metabolically, EBSS-induced starvation increased the mitochondrial content in hESC-CMs and promoted their capability of oxidative phosphorylation. Functionally, EBSS-induced starvation strengthened electrophysiological maturation, as indicated by the increased action potential duration at 90% and 50% repolarization and the calcium handling capacity. In conclusion, our data indicate that EBSS intermittent starvation is a simple and efficient approach to promote hESC-CM maturation in structure, metabolism and electrophysiology at an affordable time and cost.

Keywords: autophagy; cardiomyocyte maturation; embryonic stem cells; intermittent starvation; pluripotent stem cells.