Cas9/AAV9-Mediated Somatic Mutagenesis Uncovered the Cell-Autonomous Role of Sarcoplasmic/Endoplasmic Reticulum Calcium ATPase 2 in Murine Cardiomyocyte Maturation

Junsen Lin; Zhan Chen; Luzi Yang; Lei Liu; Peng Yue; Yueshen Sun; Mingming Zhao; Xiaoling Guo; Xiaomin Hu; Yan Zhang; Hong Zhang; Yifei Li; Yuxuan Guo; Erdan Dong

doi:10.3389/fcell.2022.864516

Cas9/AAV9-Mediated Somatic Mutagenesis Uncovered the Cell-Autonomous Role of Sarcoplasmic/Endoplasmic Reticulum Calcium ATPase 2 in Murine Cardiomyocyte Maturation

Front Cell Dev Biol. 2022 Apr 1:10:864516. doi: 10.3389/fcell.2022.864516. eCollection 2022.

Authors

Junsen Lin¹, Zhan Chen¹, Luzi Yang¹, Lei Liu², Peng Yue², Yueshen Sun^{3

4}, Mingming Zhao⁵, Xiaoling Guo⁶, Xiaomin Hu^{3

4}, Yan Zhang¹, Hong Zhang¹, Yifei Li², Yuxuan Guo¹, Erdan Dong^{1

5}

Affiliations

¹ Peking University Health Science Center, School of Basic Medical Sciences, The Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Science of Ministry of Education, Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China.
² Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education (MOE), Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China.
³ State Key Laboratory of Complex Severe and Rare Diseases, Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China.
⁴ Department of Medical Research Center, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China.
⁵ Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital, National Health Commission of China (NHC) Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Beijing Key Laboratory of Cardiovascular Receptors Research. Beijing, China.
⁶ Basic Medical Research Center, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.

Abstract

Sarcoplasmic/endoplasmic reticulum calcium ATPase 2 (SERCA2) is a key player in cardiomyocyte calcium handling and also a classic target in the gene therapy for heart failure. SERCA2 expression dramatically increases during cardiomyocyte maturation in the postnatal phase of heart development, which is essential for the heart to acquire its full function in adults. However, whether and how SERCA2 regulates cardiomyocyte maturation remains unclear. Here, we performed Cas9/AAV9-mediated somatic mutagenesis (CASAAV) in mice and achieved cardiomyocyte-specific knockout of Atp2a2, the gene coding SERCA2. Through a cardiac genetic mosaic analysis, we demonstrated the cell-autonomous role of SERCA2 in building key ultrastructures of mature ventricular cardiomyocytes, including transverse-tubules and sarcomeres. SERCA2 also exerts a profound impact on oxidative respiration gene expression and sarcomere isoform switching from Myh7/Tnni1 to Myh6/Tnni3, which are transcriptional hallmarks of cardiomyocyte maturation. Together, this study uncovered a pivotal role of SERCA2 in heart development and provided new insights about SERCA2-based cardiac gene therapy.

Keywords: Cas9/AAV9-mediated somatic mutagenesis; cardiomyocyte maturation; genetic mosaic analysis; heart failure; sarcoplasmic/endoplasmic reticulum calcium ATPase 2.