bioRxiv Science⌕ Search

Biology subjects

Vervliet, T.

Publications and source records attributed to Vervliet, T..

2 recordsLinked to original sources

Long-Term Culture of Patient-Derived Cardiac Organoids Recapitulated Duchenne Muscular Dystrophy Cardiomyopathy and Disease Progression

Duchenne Muscular Dystrophy (DMD) is an X-linked neuromuscular disease which to-date incurable. The major cause of death is dilated cardiomyopathy, however the pathogenesis is unclear as existing cellular and animal models do not fully recapitulate the human disease phenotypes. In this study, we generated cardiac organoids from patient-derived pluripotent stem cells (DMD-CO) and isogenic-corrected controls (DMD-Iso-CO) and studied if DMD-related cardiomyopathy and disease progression occur in the organoids upon long-term culture (up to 93 days). Histological analysis showed that DMD-CO lacks initial proliferative capacity, displayed a progressive loss of -sarcoglycan localization and high stress in endoplasmic reticulum. Additionally, the cardiomyocyte deteriorated over time, and fibrosis and adipogenesis were observed in DMD-CO. RNA sequencing analysis confirmed a distinct transcriptomic profile in DMD-CO which were associated with functional enrichment in hypertrophy/dilated cardiomyopathy, arrhythmia, adipogenesis and fibrosis pathways. Moreover, five miRNAs were identified to be crucial in this dysregulated gene network. In conclusion, we generated patient-derived cardiac organoid model that displayed DMD-related cardiomyopathy and disease progression phenotypes in long-term culture. We envision the feasibility to develop a more complex, realistic and reliable in vitro 3D human cardiac-mimics to study DMD-related cardiomyopathies.

cell biology↗

Cardiomyocyte differentiation from iPS cells is delayed following knockout of Bcl-2

Anti-apoptotic B-cell lymphoma 2 (Bcl-2) regulates a wide array of cellular functions involved in cell death, cell survival decisions and autophagy. Bcl-2 acts by both direct interaction with different components of the pathways involved and by intervening in intracellular Ca2+ signalling. The function of Bcl-2 is in turn regulated by post-translational modifications including phosphorylation at different sites by various protein kinases. Besides functions in cell death and apoptosis, Bcl-2 regulates cell differentiation processes, including of cardiomyocytes, although its mechanism of action in this process is not fully elucidated. To further address the role of Bcl-2 in cardiomyocyte differentiation, we investigated the effect of its genetic knockout by CRISPR/Cas9 on the differentiation and functional maturation trajectory of human induced pluripotent stem cells (hiPSC) to cardiomyocytes. Our results indicate that differentiation of hiPSC to cardiomyocytes is delayed by Bcl-2 KO. This effect was associated with smaller areas of spontaneously beating cells. At the cell population level this exhibited in reduced expression and activity of the cardiomyocyte Ca2+ toolkit. However, when restricting the comparison to the active areas exclusively Bcl-2 KO did not show to significantly alter the functionality of the differentiated cardiomyocytes. Finally, Bcl-2 KO reduced c-Myc expression early in the cardiac differentiation process which may account at least in part for the here observed delay in cardiac differentiation resulting reduced efficiency of the differentiation process. These data are supportive of a pivotal role for Bcl-2 in cardiomyocyte differentiation and maturation.

developmental biology↗