Structural and Functional Diversity of Mitochondria Isolated from Different Cell Types.

Mitochondria are essential organelles responsible for energy production, autophagy, and apoptosis, and mitochondrial dysfunction has been implicated in various diseases affecting the heart, liver, and kidneys. Mitochondrial transplantation, wherein isolated mitochondria are administered into cells or tissues, has recently emerged as a promising therapeutic approach for restoring cellular functions by enhancing ATP generation and reducing oxidative stress. However, the characteristics and functional diversity of the mitochondria isolated from different cell types remain poorly understood. Here, we aimed to identify the optimal mitochondrial source for transplantation therapy by comparing mitochondria isolated from several mammalian cell types, including mesenchymal stromal, hepatic, muscular, and pluripotent stem cells. Mitochondria were isolated using a streptolysin O-based isolation method and characterized through particle size, zeta potential, protein content, and ATP content. The isolated mitochondria exhibited uniform morphology, negative surface charge, sufficient protein yield, and ATP content, indicating successful preparation of functionally competent organelles suitable for comparative analysis. The mitochondria derived from mesenchymal stromal cells exhibited the highest bioenergetic activity. Adding these mitochondria enhanced cellular proliferation, oxygen consumption, and resistance to oxidative stress in recipient cells. Collectively, these findings demonstrate that mitochondria isolated from autologous mesenchymal stromal cells possess superior bioenergetic properties, highlighting their potential as an optimal source for mitochondrial transplantation therapy and providing new insights into the design of mitochondria-based therapeutics.