Mitochondrial-Targeted Protective Potential of Elamipretide for the In Vitro Production of Porcine Embryos

Mitochondrial-targeted antioxidant supplementation is promising for in vitro culture of mammalian embryos. Elamipretide (SS-31) is a synthetic tetrapeptide that binds to the inner mitochondrial membrane, contributing to the prevention of oxidative stress. In this study, the effects of SS-31 supplementation in maturation medium on the developmental competence of porcine oocytes and its protective function were evaluated. Porcine oocytes were matured in maturation medium with SS-31 at 0.001, 0.01, 0.1, 0.5, 1, 1.5, 2.5, and 5 µM, with 0 µM and DMSO-treated groups established as controls. In vitro fertilization and embryo culture were performed to analyze developmental potential. Oocytes cultured in medium with 1 µM SS-31 exhibited higher maturation and blastocyst formation rates than the control (0 µM) (78.3 ± 3.8% vs. 55.2 ± 4.1% and 7.6 ± 1.6% vs. 2.8 ± 1.8%, respectively). Oocytes treated with 1 µM SS-31 showed significantly lower reactive oxygen species, higher glutathione content, and improved mitochondrial membrane potential than those without treatment. DNA fragmentation in oocytes after in vitro maturation was significantly lower in the 1 µM SS-31 supplemented group than in the control. This study demonstrates that SS-31 exerts beneficial effects on the in vitro production of porcine embryos via the enhancement of the mitochondrial antioxidant capacity.