L-carnitine prevents bovine oocyte aging and promotes subsequent embryonic development

• Published in: Journal of Reproduction and Development Vol. 65; no. 6; pp. 499 - 506
• Main Authors: JIANG, Wen-Jie, YAO, Xue-Rui, ZHAO, Yu-Han, GAO, Qing-Shan, JIN, Qing-Guo, LI, Ying-Hua, YAN, ang-Guo, XU, Yong-Nan
• Format: Journal Article
• Language: English
• Published: Japan THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT 2019; Japan Science and Technology Agency; The Society for Reproduction and Development
• Subjects: Aging; Animals; Antioxidants; Apoptosis; Bcl-x protein; Bovine; Carnitine; Carnitine - pharmacology; Caspase-3; Cattle - embryology; Cattle - physiology; Cells, Cultured; Cellular Senescence - drug effects; Cellular Senescence - genetics; Cytoprotection - drug effects; Embryo development; Embryo, Mammalian; Embryogenesis; Embryonic Development - drug effects; Embryonic Development - genetics; Female; Glutathione; Glutathione - metabolism; In vitro fertilization; In Vitro Oocyte Maturation Techniques - methods; In Vitro Oocyte Maturation Techniques - veterinary; L-carnitine; Membrane potential; Membrane Potential, Mitochondrial - drug effects; Mitochondria; mRNA; Oocyte aging; Oocytes; Oocytes - drug effects; Oocytes - physiology; Original; Oxidative Stress - drug effects; Oxidative Stress - genetics; Reactive oxygen species; Reactive Oxygen Species - metabolism; Supplements; Survivin; Oocyte aging; L-carnitine; Bovine; Embryo development
• ISSN: 0916-8818; 1348-4400
• DOI: 10.1262/jrd.2019-046

L-carnitine (LC) is well known for its antioxidant activity. In this study, we explored the potential mechanistic effects of LC supplementation on aged bovine oocytes in vitro. We showed that in-vitro maturation could enhance the subsequent developmental capacity of aging oocytes, when supplemented with LC. After in vitro fertilization, the blastocyst formation rate in the aged oocytes post-LC treatment significantly increased compared to that in untreated aged oocytes (29.23 ± 2.20% vs. 20.90 ± 3.05%). Furthermore, after LC treatment, the level of intracellular reactive oxygen species in aged oocytes significantly decreased, and glutathione levels significantly increased, compared to those in untreated aged oocytes. Mitochondrial membrane potential, the percentage of early apoptotic oocytes, and caspase-3 activity were significantly reduced in LC-treated aged oocytes compared to those in untreated aged oocytes. Furthermore, during in vitro aging, the mRNA levels of the anti-apoptotic genes, Bcl-xl and survivin in LC-treated aged oocytes were significantly higher than those in untreated aged oocytes. Overall, these results indicate that at least in in vitro conditions, LC can prevent the aging of bovine oocytes and improve the developmental capacity of bovine embryo.