CNOT3 resists ovarian aging by accelerating oocyte maturation and promoting ESCs differentiation

Ovarian aging (OA), which is characterized by a decline in the quality and quantity of oocytes, represents a major challenge in reproductive medicine. However, the therapeutic targets and therapeutic methods of OA remain poorly defined. Previous studies have suggested that the embryonic stem cells (ESCs) resist mammalian OA, yet the underlying molecular mechanisms are unclear.

To assess CNOT3's role in OA and oocyte maturation, we employed RT-qPCR, Western blotting, micro-injection, and RNA seq. RNA-seq, RT-qPCR, and Western blot were used to prove the effects of Cnot3 on the differentiation of mouse ESCs into primordial germ cell-like cells (PGCLCs). Mouse ESCs were injected into mice to evaluate the therapeutic benefit of ESCs on OA.

In this study, we demonstrated that the CCR4-NOT transcription complex subunit 3 (CNOT3) played a critical regulator of OA resistance. Our results revealed that the expression of CNOT3 significantly decreased in aging ovaries of pigs and mice, compared with young ovaries. Using RNA-seq and micro-injection, we proved that CNOT3 resisted porcine OA by accelerating oocyte maturation. Moreover, Cnot3 upregulated the expressions of pluripotent genes in mouse ESCs and promoted the differentiation of ESCs into PGCLCs in vitro. Importantly, we found that tail vein injection of ESCs resisted mouse OA, while the therapeutic effects of ESCs on OA were reversed by knockdown of Cnot3.

Overall, our results indicated that CNOT3 counteracted OA and enhanced the therapeutic benefit of ESCs on OA. These findings will provide useful information for the improvement of therapeutic methods of OA.