Metabolic barriers in the transdifferentiation of fibroblasts into induced cardiac-like myocytes

• Autor(a) principal: Ferreira, Rita da Silva
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/35651
• topic: Heart failure; Direct cardiac conversion; Aging; Cardiomyocytes; Metabolism; Mitochondria

Cardiovascular diseases are the leading cause of death worldwide. These pathologies can be characterized by the loss of cardiomyocytes which, due to their very limited ability to regenerate, can lead to heart failure. Several regenerative strategies have been developed over the last years. Direct cardiac conversion (DCC) shows great promise by generating induced cardiac-like myocytes (iCLMs), through the use of cardiogenic factors (MGT; Mef2c, Gata4, and Tbx5), from fibroblasts, taking advantage of their presence in the heart, that grows after injury. Nevertheless, this strategy still lacks efficiency, especially in aged cells, and the impact of metabolic manipulations remains elusive. Using mouse embryonic fibroblasts (MEFs) and adult ear fibroblasts (AEFs), we performed an immunofluorescence analysis on mitochondrial network, revealing that DCC is accompanied by significant remodeling of the mitochondria in both MEFs and AEFs-derived iCLMs, progressing slower in the latter. We also analyzed several metabolic markers (lipid droplets, mitochondrial mass, depolarized mitochondria and reactive oxygen species) which revealed that embryonic fibroblasts are approaching a metabolism that resembles the cardiomyocytes’, while adult fibroblasts seem to have more barriers to the process. Moreover, we also improved DCC efficiency in MEFs through the use of 2-DG, a glycolytic inhibitor. Overall, our study shows that there are clear differences between embryonic and adult-derived iCLMs, which can be a starting point in improving the efficiency of the reprogramming for adult and old fibroblasts.