Mitochondria-targeted antioxidant mito-TEMPO alleviate oxidative stress induced by antimycin A in human mesenchymal stem cells.

The cell therapy of damaged tissue, which is linked to hypoxia condition might fail, in large part due to the emergence of oxidative stress (OS) and/or mitochondrial dysfunctions. Thus, the invigoration of stem cells against oxidative stress could be a reliable strategy to improve the cell therapy outcome. Of various antioxidants, mito-Tempo (mito-T) is one of the potent antioxidants that could target and neutralize the mitochondrial oxidative stress. In this study, for the induction of hypoxia and oxidative stress in mitochondria of the mesenchymal stem cells (MSCs) isolated from human adipose tissue, antimycin A (AMA) was used and then several parameters were analyzed, including cell viability and cell cycle arrest of MSCs exposed to AMA, mito-T, antioxidant potential, redox homeostasis, and signaling pathways in MSCs under oxidative stress. Based on our findings, the treated MSCs were found to impose a high resistance to the OS-induced apoptosis, which correlated with the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway required to manage OS. Upon exposure of the MSCs to high oxidative stress conditions using AMA, the cells failed to scavenge. The use of mito-T was found to alleviate the damage induced by oxidative stress through both direct functions of the free radical scavenging and the interplay in terms of cell signaling pathways including the upregulation of the Nrf2 pathway. These findings may pave the way in the stem cell therapy for the hypoxia-mediated tissue damage.