Abstract 17976: Delivery of Allogeneic Mitochondria Accelerates Revascularization in a Murine Model of Peripheral Arterial Disease and Reverses Metabolic Signatures of Endothelial Senescence

Abstract

Introduction: Peripheral arterial disease (PAD) is characterized by limb ischemia and biological therapeutics to treat PAD are limited. PAD associated with mitochondrial dysfunction in both endothelial cells and skeletal muscle. Hypothesis: Therefore, we hypothesized that mitochondrial transplantation (mito-transfer) can alleviate the cellular abnormalities linked to mitochondrial dysfunction in PAD. Methods: Mitochondria from allogeneic fibroblasts were transferred into human microvascular endothelial cells (ECs) of varying passages (p5-14) by centrifugation. After mito-transfer (24h), the metabolic activity and proliferative capacity of ECs were respectively quantified by extracellular flux analysis and EdU incorporation into DNA. Results: Compared to non-manipulated ECs, mito-transferred ECs had lower oxygen consumption rates (OCR) related to mitochondrial respiration (basal, maximal, and spare respiratory capacity, and mitochondrial ATP production). No significant differences were observed in the extracellular acidification rates related to the glycolytic activity of ECs. However, the ATP index (ratio of mitochondrial ATP/ glycolytic ATP) of late passage (p10) ECs significantly decreased after mito-transfer. Furthermore, compared to non-manipulated ECs, mito-transferred ECs of late passage (p10-14) showed a 25% increase in proliferation. Mito-transfer to the ischemic limb induced a 2-fold increase in limb perfusion after 14 days (Fig. 1). Conclusions: Collectively, these data show that EC aging is associated with increased oxidative phosphorylation metabolism and that mito-transfer decreased the senescence-associated oxidative glucose metabolism of ECs, enhanced EC proliferation, as well as accelerated revascularization in PAD. Mito-transfer is a promising strategy to treat PAD to improve revascularization and mitochondrial function.