BS62 ‘Cardiac organoids. A model to investigate the effect of diabetes on cardiac development and function’

IntroductionDiabetes and associated cardiovascular diseases (CVDs) are a class of disorders affecting the heart or blood vessels. Despite progress in clinical research and therapy, CVDs still represent the leading cause of mortality and morbidity worldwide. The hallmarks of cardiac diseases include heart dysfunction and cardiomyocyte death, inflammation, fibrosis, scar tissue, hyperplasia, hypertrophy, and abnormal ventricular remodelling. The loss of cardiomyocytes is an irreversible process that leads to fibrosis and scar formation, which, in turn, induce heart failure with progressive and dramatic consequences. Both genetic and environmental factors pathologically contribute to the development of CVDs, but the precise causes that trigger cardiac diseases and their progression are still largely unknown. The lack of reliable human model systems for such diseases has hampered the unravelling of the underlying molecular mechanisms and cellular processes involved in heart diseases at their initial stage and during their progression. In this study we use induced pluripotent stem cells (iPSCs) from diabetic and non-diabetic donors to recapitulate an iPSC-driven cardiac model with the aim of underlining the potential of stem-cell biology-based approaches in the elucidation of the pathophysiology of cardiac disease.MethodsCardiomyocytes were generated from iPS cells from both diabetic (DiPSC-CMs) and non-diabetic donors (NDiPS-CMs) within a thirteen day differentiation protocol. Cardiac commitment was assessed by Flow cytometry, PCR analysis, and Immunofluorescence staining. Morphological features of the sarcomere arrangement and mitochondria size were assessed using TEM microscopy. Cardiac function was measured by assessing calcium flux using Flexstation. Beating qualities were assessed by Nikon 6D Life imaging.ResultsUpon differentiation both DiPSC-CMs and NDiPSC-CMs presented strong cardiac commitment as evident by the significant expression of cardiac markers evaluated by PCR and flow cytometry. iPS-CM from both donors presented no significant differences in the expression of cardiac markers brachyury and cardiac troponin as assessed by flow cytometry (p > 0.7078) and sarcomere proteins a-Actinin, myosin light chain MLCA2 assessed by immunofluorescence staining. Cardiomyocytes derived from diabetic donors (DiPS-CMs) showed differences in the uptake of calcium when these compared to the nondiabetic counterparts (NDiPS-CMs). Calcium flux was measure by capturi