PAKISTAN VETERINARY JOURNAL

Pak Vet J, 2026, 46(5) 1209-1218

Restoration of Mitochondrial Homeostasis in Post-Ovulatory Ageing Oocytes Through Elamipretide–Mediated Modulation of SIRT3, Redox Balance, and Bioenergetics

Alicja Kowalczyk^1*, Mercedes Camiña García², José Ángel Hernández Malagón ³, Jose Pedro Araujo⁴, Wojciech Witkiewicz⁵, Joanna Gruszczyńska⁶, Marko Samardžija⁷ Marcjanna Wrzecińska¹, Elżbieta Gałęska¹, Ewa Czerniawska-Piątkowska⁸ and Zbigniew Dobrzański¹

¹Department of Environment Hygiene and Animal Welfare, Wrocław University of Environmental and Life Sciences, Wrocław, Poland; ²Department of Physiology, Faculty of Veterinary, University of Santiago de Compostela, 27002 Lugo, Spain; ³COPAR (GI-2120) Research Group, Department of Animal Pathology, Faculty of Veterinary, Campus Terra, University of Santiago de Compostela, 27002, Lugo, Spain; ⁴Escola Superior Agrária, Inst. Polit. de Viana do Castelo, Refóios do Lima, 4990-706 Ponte de Lima, Portugal; ⁵Research and Development Center, Voivodeship Specialist Hospital in Wrocław, 51-124 Wrocław, Poland; ⁶Department of Animal Genetic and Conservation, Warsaw University of Life Sciences, Institute of Animal Sciences, Warsaw, Poland; ⁷Clinic for Reproduction and Obstetrics, Veterinary Faculty, University of Zagreb, Heinzelova 55, 10000 Zagreb, Croatia; ⁸Department of Ruminant Science, West Pomeranian University of Technology in Szczecin, Poland

*Corresponding author: alicja.kowalczyk@upwr.edu.pl

Abstract

The study investigated whether the mitochondrial-targeted antioxidant peptide SS-31 (elamipretide) can mitigate post-ovulatory ageing-related mitochondrial dysfunction in bovine oocytes by modulating SIRT3 expression, oxidative stress, ATP content and mitochondrial membrane potential during in vitro maturation. Cumulus–oocyte complexes were collected from bovine ovaries and matured for 12, 36, or 52 hours and treated with SS-31 at 0.3, 0.6, or 0.9 µM, or cultured without antioxidants. SIRT3 expression was quantified by immunofluorescence, reactive oxygen species levels were measured using fluorescent probes, ATP content was evaluated using bioluminescence assays, and mitochondrial membrane potential was evaluated using JC-1 staining. Data were analyzed using two-way analysis of variance (ANOVA) with post hoc testing. SS-31 led to a dose-dependent increase in SIRT3 expression at all time points. ROS levels increased with duration of incubation; however, SS-31 treatment notably reduced oxidative stress, particularly at early and mid stage incubation. The ATP content increased over time, but remained lower in oocytes treated with SS-31, which may reflect alterations in mitochondrial metabolism; however, this requires further investigation. Mitochondrial membrane potential was enhanced by SS-31, with the strongest improvement observed at 0.6 µM after 12 and 36 hours. SS-31 appears to alleviate age-associated mitochondrial deterioration by improving SIRT3 expression, reducing ROS accumulation, and stabilizing mitochondrial membrane potential. In this context, SS-31 appears to support oocyte bioenergetic quality and may represent a promising approach as a tool for improving reproductive outcomes, particularly in cases of age-related fertility decline.

To Cite This Article: Kowalczyk A, García MC, Malagón JAH, Araujo JP, Witkiewicz W, Gruszczyńska J, Samardžija M, Wrzecińska M, Gałęska E, Czerniawska-Piątkowska E and Dobrzański Z, 2026. Restoration of mitochondrial homeostasis in post-ovulatory ageing oocytes through elamipretide–mediated modulation of SIRT3, redox balance, and bioenergetics. Pak Vet J, 46(5): 1209-1218. http://dx.doi.org/10.29261/pakvetj/2026.108

Abstract

ISSN 0253-8318 (Print)ISSN 2074-7764 (Online)

ISSN 0253-8318 (Print)
ISSN 2074-7764 (Online)