Rescue of follicle development after oocyte-induced ovary dysfunction and infertility in a model of POI

• Published in: Frontiers in cell and developmental biology 2023-08, Vol.11, p.1202411
• Main Authors: Sheikh, Sairah, Lo, Belinda K M, Kaune, Heidy, Bansal, Jassimran, Deleva, Anna, Williams, Suzannah A
• Format: Article
• Language: English
• Subjects: Cell and Developmental Biology; follicle development; granulosa cells; oocyte; premature ovarian failure; primary follicle; primary ovarian insufficiency
• ISSN: 2296-634X; 2296-634X
• DOI: 10.3389/fcell.2023.1202411

The mechanisms and aetiology underlying the development of premature ovarian insufficiency (POI) are poorly understood. However, the oocyte clearly has a role as demonstrated by the Double Mutant (DM) mouse model where ovarian dysfunction (6 weeks) is followed by POI (3 months) due to oocyte-specific deletion of complex and hybrid N- and O-glycans. The ovaries of DM mice contain more primary follicles (3a stage) accompanied by fewer developing follicles, indicating a block in follicle development. To investigate this block, we first analysed early follicle development in postnatal (8-day), pre-pubertal (3-week) and post-pubertal (6-week and 3-month) DM ( :ZP3 ) and Control ( ) mice. Second, we investigated if transplantation of DM ovaries into a "normal" endocrine environment would restore follicle development. Third, we determined if replacing DM ovarian somatic cells would rescue development of DM oocytes. At 3-week, DM primary 3a follicles contain large oocytes accompanied by early development of a second GC layer and increased GC proliferation. At 6-week, DM primary 3a follicles contain abnormally large oocytes, accompanied with decreased GC proliferation. Transplantation of DM ovaries into a 'normal' endocrine environment did not restore normal follicle development. However, replacing somatic cells by generating reaggregated ovaries (ROs) did enable follicle development to progress and thus highlighted intra-ovarian factors were responsible for the onset of POI in DM females. Thus, these studies demonstrate oocyte-initiated altered communication between GCs and oocytes results in abnormal primary follicles which fail to progress and leads to POI.