Taurine alleviates postovulatory oocyte aging via TBK1 associated mitophagy in pigs and mice

Taurine deficiency is a driver of aging, however the mechanisms by which taurine regulates postovulatory oocyte aging (POA) remain an unanswered question. Here, we used differential gene expressions and functional enrichment analysis of transcriptomes to determine transcriptional dynamics in POA. Transcriptional conservation between mouse and pig was determined by comparative analysis of transcriptomes. Candidate key targets were identified by WGCNA analysis combined with comparative analysis of transcriptomes. Expression levels were validated using cell-based immunofluorescence assays. We observed increased fragmentation and apoptosis of oocytes during POA, which was significantly improved after adding taurine. Transcriptome analysis showed that mitochondrial function was disrupted in oocytes. Our mitochondrial immunofluorescence assay showed that mitochondrial distribution in the POA group was abnormal compared with fresh group, and ROS levels were increased. Moreover, comparative analysis highlighted the role of mitophagy, and the immunofluorescence assay highlighted the significant decrease in PINK1. On the note, we combined comparative analysis and WGCNA results to identify TBK1 as a key gene, subsequent protein fluorescence confirmed that TBK1 was downregulated during POA. As expected, the taurine increased the expression level of TBK1 in the aged group. In summary, our evidence demonstrates that taurine can improve oocyte quality during POA via TBK1-associated mitophagy.