Mesenchymal Stem Cells Modulate Granulosa Cell Function Under Inflammatory and Hypoxic Conditions

Background/Objectives: Increasing evidence points to hypoxia and inflammation as two major causes of compromised ovarian function. Increased oxidative stress under hypoxic conditions can damage cellular components, leading to the dysfunction and apoptosis of granulosa cells (GCs). The inflammatory response induced by hypoxia may further impair the function of the ovaries and contribute to the development of premature ovarian insufficiency (POI). In animal models of premature ovarian failure, research has demonstrated that the transplantation of mesenchymal stem cells (MSCs) can enhance reproductive outcomes, increase the number of functioning ovarian follicles, and restore estradiol production. However, the specific mechanisms underlying the observed positive results are not well understood. Methods: The present study provides a comparative analysis of how MSCs influence human GC function under inflammatory and hypoxic conditions, using three different experimental approaches: direct co-culture, indirect co-culture with transwell cell culture inserts, and treatment with MSC-derived conditioned medium (MSCcm). Results: Inflammation significantly suppressed GC estradiol secretion and increased apoptosis. MSCs increased estradiol secretion in normal and hypoxic culture conditions when co-cultured directly with GCs. Our results also showed that, under inflammation, MSCs tended to decrease GC proliferation and that hypoxia alone did not have an effect on GC estradiol secretion or proliferation. Conclusions: The study emphasizes the dual nature of MSCs, which largely determines their effects on other cell types, and the need for the condition-specific optimization of MSC therapies for ovarian regeneration.