RAD-Deficient Human Cardiomyocytes Develop Hypertrophic Cardiomyopathy Phenotypes Due to Calcium Dysregulation

Ya'nan Li; Yun Chang; Xiaolei Li; Xiaowei Li; Jian Gao; Yafei Zhou; Fujian Wu; Rui Bai; Tao Dong; Shuhong Ma; Siyao Zhang; Wen-Jing Lu; Xiaoqiu Tan; Yongming Wang; Feng Lan

doi:10.3389/fcell.2020.585879

RAD-Deficient Human Cardiomyocytes Develop Hypertrophic Cardiomyopathy Phenotypes Due to Calcium Dysregulation

Front Cell Dev Biol. 2020 Oct 22:8:585879. doi: 10.3389/fcell.2020.585879. eCollection 2020.

Authors

Ya'nan Li^{1

2}, Yun Chang^{1

2}, Xiaolei Li³, Xiaowei Li^{1

2}, Jian Gao⁴, Yafei Zhou⁵, Fujian Wu^{1

2}, Rui Bai^{1

2}, Tao Dong^{1

2}, Shuhong Ma^{1

2}, Siyao Zhang^{1

2}, Wen-Jing Lu^{1

2}, Xiaoqiu Tan⁵, Yongming Wang⁶, Feng Lan^{1

2

7}

Affiliations

¹ Beijing Laboratory for Cardiovascular Precision Medicine, MOE Key Laboratory of Medical Engineering for Cardiovascular Diseases, MOE Key Laboratory of Remodeling-Related Cardiovascular Disease, Beijing Collaborative Innovation Center for Cardiovascular Disorders, Anzhen Hospital, Capital Medical University, Beijing, China.
² Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China.
³ Department of Cardiology, Heart Center, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, China.
⁴ Experimental Medicine, Faculty of Medicine, Vancouver, BC, Canada.
⁵ Key Laboratory of Medical Electrophysiology of the Ministry of Education, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China.
⁶ The State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China.
⁷ State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.

Abstract

Ras associated with diabetes (RAD) is a membrane protein that acts as a calcium channel regulator by interacting with cardiac L-type Ca^{2 +} channels (LTCC). RAD defects can disrupt intracellular calcium dynamics and lead to cardiac hypertrophy. However, due to the lack of reliable human disease models, the pathological mechanism of RAD deficiency leading to cardiac hypertrophy is not well understood. In this study, we created a RRAD ^-/- H9 cell line using CRISPR/Cas9 technology. RAD disruption did not affect the ability and efficiency of cardiomyocytes differentiation. However, RAD deficient hESC-CMs recapitulate hypertrophic phenotype in vitro. Further studies have shown that elevated intracellular calcium level and abnormal calcium regulation are the core mechanisms by which RAD deficiency leads to cardiac hypertrophy. More importantly, management of calcium dysregulation has been found to be an effective way to prevent the development of cardiac hypertrophy in vitro.

Keywords: HCM; L-type Cacpsdummy2+ channels; RAD deficiency; RRAD knockout; calcium channel blocker; calcium handling.