PMID- 31376814 OWN - NLM STAT- MEDLINE DCOM- 20201030 LR - 20201030 IS - 1741-7899 (Electronic) IS - 1470-1626 (Linking) VI - 159 IP - 1 DP - 2020 Jan TI - Advances in human primordial follicle activation and premature ovarian insufficiency. PG - R15-R29 LID - REP-19-0201 [pii] LID - 10.1530/REP-19-0201 [doi] AB - In women, the non-growing population of follicles that comprise the ovarian reserve is determined at birth and serves as the reservoir for future fertility. This reserve of dormant, primordial follicles and the mechanisms controlling their selective activation which constitute the committing step into folliculogenesis are essential for determining fertility outcomes in women. Much of the available data on the mechanisms responsible for primordial follicle activation focuses on a selection of key molecular pathways, studied primarily in animal models, with findings often not synonymous in humans. The excessive induction of primordial follicle activation may cause the development of premature ovarian insufficiency (POI), a condition characterised by menopause before age 40 years. POI affects 1-2% of all women and is accompanied by additional health risks. Therefore, it is critical to further our understanding of primordial follicle activation in order to diagnose, treat and prevent premature infertility. Research in primordial follicle activation has focused on connecting new molecules to already established key signalling pathways, such as phosphatidylinositol 3-Kinase (PI3K) and mammalian target of rapamycin (mTOR). Additionally, other aspects of the ovarian environment, such as the function of the extracellular matrix, in contributing to primordial follicle activation have gained traction. Clinical applications are examining replication of this extracellular environment through the construction of biological matrices mimicking the 3D ovary, to support follicular growth through to ovulation. This review outlines the importance of the events leading to the establishment of the ovarian reserve and highlights the fundamental factors known to influence primordial follicle activation in humans presenting new horizons for female infertility treatment. FAU - Ford, Emmalee A AU - Ford EA AD - Priority Research Centre for Reproductive Science, Schools of Biomedical Science & Pharmacy and Environmental & Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia. AD - Hunter Medical Research Institute, New Lambton Heights, New South Wales, Australia. FAU - Beckett, Emma L AU - Beckett EL AD - Hunter Medical Research Institute, New Lambton Heights, New South Wales, Australia. AD - School of Environmental & Life Sciences, Faculty of Science, University of Newcastle, Callaghan, New South Wales, Australia. FAU - Roman, Shaun D AU - Roman SD AD - Priority Research Centre for Reproductive Science, Schools of Biomedical Science & Pharmacy and Environmental & Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia. AD - Hunter Medical Research Institute, New Lambton Heights, New South Wales, Australia. AD - Priority Research Centre for Drug Development, University of Newcastle, Callaghan, New South Wales, Australia. FAU - McLaughlin, Eileen A AU - McLaughlin EA AD - Priority Research Centre for Reproductive Science, Schools of Biomedical Science & Pharmacy and Environmental & Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia. AD - School of Science, Faculty of Science & Technology, University of Canberra, Bruce, Australian Capital Territory, Australia. AD - School of Biological Sciences, Faculty of Science, University of Auckland, Auckland, New Zealand. FAU - Sutherland, Jessie M AU - Sutherland JM AD - Priority Research Centre for Reproductive Science, Schools of Biomedical Science & Pharmacy and Environmental & Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia. AD - Hunter Medical Research Institute, New Lambton Heights, New South Wales, Australia. LA - eng PT - Journal Article PT - Review PL - England TA - Reproduction JT - Reproduction (Cambridge, England) JID - 100966036 SB - IM MH - Female MH - Fertility Preservation MH - Humans MH - Infertility, Female/*prevention & control MH - Oocytes/cytology/*physiology MH - Ovarian Follicle/cytology/*physiology MH - Primary Ovarian Insufficiency/*therapy EDAT- 2019/08/04 06:00 MHDA- 2020/10/31 06:00 CRDT- 2019/08/04 06:00 PHST- 2019/05/06 00:00 [received] PHST- 2019/08/01 00:00 [accepted] PHST- 2019/08/04 06:00 [pubmed] PHST- 2020/10/31 06:00 [medline] PHST- 2019/08/04 06:00 [entrez] AID - REP-19-0201 [pii] AID - 10.1530/REP-19-0201 [doi] PST - ppublish SO - Reproduction. 2020 Jan;159(1):R15-R29. doi: 10.1530/REP-19-0201.