Supplementation with L-kynurenine during in vitro maturation improves bovine oocytes developmental competence through its antioxidative action

Canqiang Lu; Yun Feng; Zhenhua Tang; Ruru Jia; Fan Xia; Tingzi Yu; Heng Wang; Hongfang Mo; Deshun Shi; Fenghua Lu

doi:10.1016/j.theriogenology.2024.11.014

Supplementation with L-kynurenine during in vitro maturation improves bovine oocytes developmental competence through its antioxidative action

Theriogenology. 2024 Nov 20:233:53-63. doi: 10.1016/j.theriogenology.2024.11.014. Online ahead of print.

Authors

Canqiang Lu¹, Yun Feng², Zhenhua Tang³, Ruru Jia¹, Fan Xia¹, Tingzi Yu¹, Heng Wang¹, Hongfang Mo¹, Deshun Shi¹, Fenghua Lu⁴

Affiliations

¹ State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Guangxi University, Nanning, 530005, China.
² Birth Defects Prevention and Control Institute, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530003, China.
³ State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Guangxi University, Nanning, 530005, China; Guangxi Zhuang Nationality Autonomous Region Buffalo Research Institute, Chinese Academy of Agricultural Science, Ministry of Agriculture, Nanning, 530001, China.
⁴ State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Guangxi University, Nanning, 530005, China. Electronic address: lfhgggg@163.com.

PMID: 39579654
DOI: 10.1016/j.theriogenology.2024.11.014

Abstract

Oxidative stress impairs the developmental potential of oocytes during in vitro maturation (IVM). L-kynurenine (L-KYN), an endogenous metabolite, exhibits antioxidant, anti-inflammatory and neuroprotective effects. This work aimed to evaluate the potential effects of L-KYN on bovine oocyte IVM and its mechanisms. Different concentrations of L-KYN (0, 10, 50, 100, and 200 μmol/L) were supplemented to bovine oocyte IVM medium. Results shown a notable enhancement in the oocyte maturation rate and the subsequent zygote cleavage and blastocyst formation rate when the L-KYN concentration reached 100 μmol/L. Further analysis revealed that this treatment effectively down-regulated expression levels of genes to cumulus cell apoptosis (Bax and Caspase3), up-regulated expression levels of genes to cumulus cell expansion (HAS2, PTX3, and PTGS2) and oocyte antioxidant (GPX4 and CAT). L-KYN supplementation also effectively increased glutathione (GSH) levels, promoted oocytes mitochondrial activity, enhanced DNA repairability, deceased reactive oxygen species (ROS) levels, and reduced apoptosis. In conclusion, adding 100 μmol/L of L-KYN to IVM medium could enhance bovine oocyte quality and the subsequent embryonic development. L-KYN could be a potential antioxidant supplement for bovine oocyte maturation in vitro.

Keywords: Antioxidant; Bovine; In vitro maturation; L-kynurenine; Oocytes.