Mitochondrial transfer from human embryonic stem cell-derived mature cardiomyocytes to mesenchymal stem cells

Mitochondria are crucial for energy metabolism and their dysfunction is implicated in the development of various human diseases. Direct mitochondrial transplantation has shown potential in reversing mitochondrial dysfunction in recipient cells. Mesenchymal stem cells (MSCs) present a promising approach as donor cells for such transplantation. We have previously demonstrated that tomatidine, a natural steroidal alkaloid, promotes the differentiation of human embryonic stem cells (hESCs) into mature cardiomyocytes by enhancing mitochondrial quantity and function. In this study, we assessed the capacity of hESCderived cardiomyocytes (hESC-CMs) and MSCs as donor cells for mitochondrial transplantation. Mitochondria were extracted from MSCs, immature hESC-CMs, and tomatidine-treated mature hESC-CMs. Treating MSCs with mitochondria derived from mature hESC-CMs led to a marked increase in mitochondrial protein levels, such as COX IV and MIC60, in the recipient MSCs, in comparison to those receiving mitochondria from immature hESC-CMs or MSCs. Transplantation of mature hESC-CM-derived mitochondria significantly enhanced the proliferation of recipient MSCs. These findings indicate that mature hESC-CMs are highly effective as donor cells for mitochondrial transplantation in addressing mitochondrial dysfunction.