Objective: To identify differences in the expression of the genes for peroxisome proliferator-activated receptor (PPAR)-γ, cyclooxygenase (COX)-2, and the proinflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α in granulosa cells (GCs) from polycystic ovary syndrome (PCOS) patients and controls undergoing controlled ovarian stimulation.
Methods: Nine patients with PCOS and six controls were enrolled in this study. On the day of oocyte retrieval, GCs were collected from pooled follicular fluid. Total mRNA was extracted from GCs. Reverse transcription was performed and gene expression levels were quantified by realtime quantitative polymerase chain reaction.
Results: There were no significant differences in age, body mass index, and total gonadotropin dose, except for the ratio of luteinizing hormone to follicle-stimulating hormone between the PCOS and control groups. PPAR-γ and COX-2 mRNA was significantly downregulated in the GCs of PCOS women compared with controls (p=0.034 and p=0.018, respectively), but the expression of IL-6 and TNF-α mRNA did not show significant differences. No significant correlation was detected between the expression of these mRNA sequences and clinical characteristics, including the number of retrieved oocytes, oocyte maturity, cleavage, or the good embryo rate. Positive correlations were found among the PPAR-γ, COX-2, IL-6, and TNF-α mRNA levels.
Conclusion: Our data may provide novel clues regarding ovarian GC dysfunction in PCOS, and indirectly provide evidence that the effect of PPAR-γ agonists in PCOS might result from alterations in the ovarian follicular environment. Further studies with a larger sample size are required to confirm these proposals.
Keywords: Cyclooxygenase 2; Granulosa cells; Interleukin-6; Peroxisome proliferator-activated receptor gamma; Polycystic ovary syndrome; Tumor necrosis factor-alpha.