Multi-omics profiling uncovers metabolic regulation in cumulus cells during oocyte maturation.

Bidirectional signalling between the oocyte and surrounding cumulus cells is essential for coordinating follicular development and acquiring oocyte competence. The metabolic networks governing bovine cumulus cell function, however, remain poorly characterized. To address this gap, we performed integrated metabolomic and proteomic analyses of cumulus cells isolated from cumulus-oocyte complexes at two critical maturation stages: (1) meiotically arrested germinal vesicle stage (0 h) and (2) metaphase II stage (24 h). This temporal profiling reveals dynamic metabolic reprogramming events supporting oocyte maturation. In particular, we found the active use of glucose metabolism via glycolysis and the pentose phosphate pathway, rather than the citric cycle, suppression in fatty acid β-oxidation, and active tryptophan and polyamine biosynthesis. Meanwhile, the surrounding cumulus cells showed a steady rise in steroid hormone production and one-carbon metabolism in tandem with the development of the oocyte. In sum, the data provide a comprehensive metabolic atlas of cumulus cell differentiation and give prospective indicators for enhancing and predicting oocyte quality.