Notch signaling is involved in ovarian follicle development by regulating granulosa cell proliferation

Area of Science:

• Reproductive Biology
• Cell Signaling
• Developmental Biology

Background:

• Notch signaling regulates key cellular processes like proliferation and differentiation.
• While present in mammalian ovaries, its specific role in follicle development remains largely unknown.

Purpose of the Study:

• To investigate the function of Notch signaling in mammalian ovarian follicle development.
• To determine the impact of Notch signaling inhibition on primary follicle growth and granulosa cell proliferation.

Main Methods:

• In vitro culture of primary ovarian follicles and granulosa cells.
• Treatment with Notch signaling inhibitors (L-658,458 and DAPT).
• Assessment of follicle development, cell viability, proliferation markers (c-Myc), and gene expression via lentivirus-mediated overexpression.

Main Results:

• Notch inhibition completely arrested follicle development, leading to granulosa cell detachment and oocyte degeneration.
• Granulosa cell proliferation was dependent on Notch signaling, with inhibitor treatment decreasing proliferation and c-Myc expression.
• Overexpression of Notch intracellular domain 2 and c-Myc rescued proliferation defects caused by Notch inhibition.

Conclusions:

• Notch signaling is essential for mammalian ovarian follicle development.
• The pathway regulates follicle growth primarily by controlling granulosa cell proliferation.
• Targeting Notch signaling impacts granulosa cell viability and function.