Reduced anti-Müllerian hormone action in cumulus-oocyte complexes is beneficial for oocyte maturation without
Fuhua Xu1, Konstantin Bagnjuk2, Nuria Marti-Gutierrez3
1Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, MD, United States.
Abstract:
Anti-Müllerian hormone (AMH) is a key paracrine/autocrine factor regulating folliculogenesis in the postnatal ovary. As antral follicles mature to the preovulatory stage, AMH production tends to be limited to cumulus cells. Therefore, the present study investigated the role of cumulus cell-derived AMH in supporting maturation and competence of the enclosed oocyte. Cumulus-oocyte complexes (COCs) were isolated from antral follicles of rhesus macaque ovaries for in vitro maturation with or without AMH depletion. Oocyte meiotic status and embryo cleavage after in vitro fertilization were assessed. In vitro maturation with AMH depletion was also performed using COCs from antral follicles of human ovarian tissue. Oocyte maturation and morphology were evaluated. The direct AMH action on mural granulosa cells of the preovulatory follicle was further assessed using human granulosa cells cultured with or without AMH supplementation. More macaque COCs produced metaphase II oocytes with AMH depletion than those of the control culture. However, preimplantation embryonic development after in vitro fertilization was comparable between oocytes derived from COCs cultured with AMH depletion and controls. Oocytes resumed meiosis in human COCs cultured with AMH depletion and exhibited a typical spindle structure. The confluency and cell number decreased in granulosa cells cultured with AMH supplementation relative to the control culture. AMH treatment did not induce cell death in cultured human granulosa cells. Data suggest that reduced AMH action in COCs could be beneficial for oocyte maturation. Cumulus cell-derived AMH is not essential for supporting oocyte competence or mural granulosa cell viability.
Insights
Reducing Anti-Müllerian hormone (AMH) in cumulus cells improved oocyte maturation in vitro. However, AMH from cumulus cells is not essential for oocyte competence or granulosa cell health.
Area of Science:
- Reproductive Biology
- Endocrinology
- Cell Biology
Background:
- Anti-Müllerian hormone (AMH) regulates ovarian folliculogenesis.
- During follicle maturation, AMH production is primarily localized to cumulus cells.
- The specific role of cumulus cell-derived AMH in oocyte maturation and competence remains unclear.
Purpose of the Study:
- To investigate the function of cumulus cell-derived AMH in supporting oocyte maturation and competence.
- To assess the impact of AMH depletion on oocyte meiotic status and subsequent embryonic development.
- To evaluate the direct effects of AMH on human granulosa cells.
Main Methods:
- Cumulus-oocyte complexes (COCs) from rhesus macaques and human ovarian tissue underwent in vitro maturation with and without AMH depletion.
- Oocyte meiotic progression and embryo cleavage rates post-in vitro fertilization were assessed.
- Human granulosa cells were cultured with or without AMH supplementation to evaluate direct cellular effects.
Main Results:
- AMH depletion in macaque COCs resulted in a higher yield of metaphase II oocytes compared to controls.
- Despite improved maturation rates, no significant differences in preimplantation embryonic development were observed.
- Human oocytes matured in AMH-depleted conditions showed normal meiotic resumption and spindle morphology; AMH supplementation decreased granulosa cell confluency and number without inducing cell death.
Conclusions:
- Reduced AMH action within COCs may enhance in vitro oocyte maturation.
- Cumulus cell-derived AMH is not critical for maintaining oocyte competence or mural granulosa cell viability.
- Further research is warranted to elucidate the precise role of AMH in the complex process of folliculogenesis and oocyte development.
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