Adipose-derived stem cells exosomal circHIPK3 protects ovarian function by regulating MAPK signaling.

Background: Exosomes derived from adipose-derived stem cells (ADSCs) have garnered significant attention for their therapeutic potential in various diseases. These vesicles are capable of transporting bioactive molecules such as noncoding RNAs and proteins. Among these noncoding RNAs, circular RNAs (circRNAs) are characterized as end-to-end circular structures, which are notably enriched within exosomes.

Objective: This study aims to investigate the impact of the circHIPK3 delivered via ADSC-derived exosomes on ovarian aging.

Materials And Methods: ADSCs were isolated, and exosomes were obtained from a cell culture medium. The exosomes were labeled with PKH26, and uptake by primary granulosa cells (pGCs) was detected. ADSCs were transfected with circHIPK3 siRNAs, and the exosomes were isolated for the treatment of aging female mice. Ovary weight was recorded, and HE staining, Masson's trichrome, and TUNEL staining were performed to detect tissue morphology and apoptosis in ovary tissues. In addition, the senescence and apoptosis of pGCs were evaluated using the S-β-gal staining kit and Annexin V/PI detection kit. Further experiments included immunoprecipitation and RNA pulldown, determined the ubiquitination of p38 protein under circHIPK3 alteration.

Results: Results showed that ADSC-derived exosomes effectively delivered circHIPK3 to pGCs. Treatment with these exosomes significantly increased ovary weight and enhanced follicular development in aged mice. Conversely, the depletion of circHIPK3 reversed these effects, promoting cell apoptosis. ADSC-derived exosomes also mitigated senescence and apoptosis in pGCs, while circHIPK3 depletion hindered these benefits.

Conclusion: Exosomal circHIPK3 modulated the ubiquitination of p38 in pGCs to improve ovarian function in aging mice and to promote pGC cell viability.