Chrishan J A Ramachandra1, Ashish Mehta2, Philip Wong3, K P Myu Mai Ja4, Regina Fritsche-Danielson5, Ratan V Bhat6, Derek J Hausenloy7, Jean-Paul Kovalik8, Winston Shim9. 1. National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore; Cardiovascular & Metabolic Disorders Program, Duke-NUS Medical School, Singapore. 2. PSC and Phenotyping Laboratory, Victor Chang Cardiac Research Institute, Sydney, Australia. 3. National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore; Cardiovascular & Metabolic Disorders Program, Duke-NUS Medical School, Singapore; Department of Cardiology, National Heart Centre Singapore, Singapore; School of Materials Science and Engineering, Nanyang Technological University, Singapore. Electronic address: philip.wong.e.h@nhcs.com.sg. 4. National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore. 5. Cardiovascular and Metabolic Disease Innovative Medicines and Early Development Unit, AstraZeneca Research and Development, Gothenburg, Sweden. 6. Strategy and External Innovation Department, AstraZeneca, Gothenburg, Sweden. 7. National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore; Cardiovascular & Metabolic Disorders Program, Duke-NUS Medical School, Singapore; The Hatter Cardiovascular Institute, University College London, United Kingdom; Barts Heart Centre, St Barthlomew's Hospital, London, United Kingdom; Yong Loo Lin School of Medicine, National University of Singapore, Singapore. 8. Cardiovascular & Metabolic Disorders Program, Duke-NUS Medical School, Singapore. 9. National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore; Cardiovascular & Metabolic Disorders Program, Duke-NUS Medical School, Singapore; Health and Social Sciences Cluster, Singapore Institute of Technology, Singapore. Electronic address: winston.shim@singaporetech.edu.sg.
Abstract
BACKGROUND: Preferential utilization of fatty acids for ATP production represents an advanced metabolic phenotype in developing cardiomyocytes. We investigated whether this phenotype could be attained in human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) and assessed its influence on mitochondrial morphology, bioenergetics, respiratory capacity and ultra-structural architecture. METHODS AND RESULTS: Whole-cell proteome analysis of day 14 and day 30-CMs maintained in glucose media revealed a positive influence of extended culture on mitochondria-related processes that primed the day 30-CMs for fatty acid metabolism. Supplementing the day 30-CMs with palmitate/oleate (fatty acids) significantly enhanced mitochondrial remodeling, oxygen consumption rates and ATP production. Metabolomic analysis upon fatty acid supplementation revealed a β-oxidation fueled ATP elevation that coincided with presence of junctional complexes, intercalated discs, t-tubule-like structures and adult isoform of cardiac troponin T. In contrast, glucose-maintained day 30-CMs continued to harbor underdeveloped ultra-structural architecture and more subdued bioenergetics, constrained by suboptimal mitochondria development. CONCLUSION: The advanced metabolic phenotype of preferential fatty acid utilization was attained in hiPSC-CMs, whereby fatty acid driven β-oxidation sustained cardiac bioenergetics and respiratory capacity resulting in ultra-structural and functional characteristics similar to those of developmentally advanced cardiomyocytes. Better understanding of mitochondrial bioenergetics and ultra-structural adaptation associated with fatty acid metabolism has important implications in the study of cardiac physiology that are associated with late-onset mitochondrial and metabolic adaptations.
BACKGROUND: Preferential utilization of fatty acids for ATP production represents an advanced metabolic phenotype in developing cardiomyocytes. We investigated whether this phenotype could be attained in human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) and assessed its influence on mitochondrial morphology, bioenergetics, respiratory capacity and ultra-structural architecture. METHODS AND RESULTS: Whole-cell proteome analysis of day 14 and day 30-CMs maintained in glucose media revealed a positive influence of extended culture on mitochondria-related processes that primed the day 30-CMs for fatty acid metabolism. Supplementing the day 30-CMs with palmitate/oleate (fatty acids) significantly enhanced mitochondrial remodeling, oxygen consumption rates and ATP production. Metabolomic analysis upon fatty acid supplementation revealed a β-oxidation fueled ATP elevation that coincided with presence of junctional complexes, intercalated discs, t-tubule-like structures and adult isoform of cardiac troponin T. In contrast, glucose-maintained day 30-CMs continued to harbor underdeveloped ultra-structural architecture and more subdued bioenergetics, constrained by suboptimal mitochondria development. CONCLUSION: The advanced metabolic phenotype of preferential fatty acid utilization was attained in hiPSC-CMs, whereby fatty acid driven β-oxidation sustained cardiac bioenergetics and respiratory capacity resulting in ultra-structural and functional characteristics similar to those of developmentally advanced cardiomyocytes. Better understanding of mitochondrial bioenergetics and ultra-structural adaptation associated with fatty acid metabolism has important implications in the study of cardiac physiology that are associated with late-onset mitochondrial and metabolic adaptations.
Authors: Chrishan J A Ramachandra; Jasper Chua; Shuo Cong; Myu Mai Ja Kp; Winston Shim; Joseph C Wu; Derek J Hausenloy Journal: Cardiovasc Res Date: 2021-02-22 Impact factor: 10.787