Thiazolidinediones decrease vascular endothelial growth factor (VEGF) production by human luteinized granulosa cells in vitro

Abstract

Overproduction of VEGF by granulosa cells of the corpus luteum is implicated in the development of ovarian hyperstimulation syndrome (OHSS). Thiazolidinedione derivatives are synthetic ligands of peroxisome proliferator activated receptor-gamma (PPAR-γ) that have been shown to decrease VEGF production in a variety of human cell types. We sought to assess the in vitro effect of a commercially available thiazolidinedione agonist, ciglitazone (CIG), on VEGF production by human luteinized granulosa cells. Prospective, experimental in vitro study. Ovarian follicular aspirates were obtained from ten women undergoing oocyte retrieval as part of an in vitro fertilization program. Granulosa cells were isolated and plated in duplicate in 24-well plates at a density of 50,000 viable cells per mL. On day 2 of culture, the cells were treated with a DMSO control, 10 μM, 20 μM, and 40 μM CIG, both in the presence and absence of a 2.7 μM hCG stimulus. Media was harvested 24 and 48 hours post-treatment. VEGF concentrations were measured using specific ELISA kits. Comparisons of VEGF concentrations between treatment groups were made using a one-way ANOVA with post hoc Bonferroni test. All three doses of CIG decreased VEGF production in a statistically significant fashion 48 hours after treatment in those cells not exposed to hCG (P<0.01), but only the 40 μM concentration achieved statistical significance at the 24 hour time interval (896 pg/mL vs. 335 pg/mL, P<0.01). Following an hCG stimulus, treatment with 10 μM, 20 μM or 40 μM CIG decreased VEGF production in a statistically significant manner at both the 24 and 48 hour time intervals. The effect appeared dose related, with a 45% diminution in VEGF production when cells were treated with 10 μM CIG (1987 pg/ml vs. 1091 pg/ml, P<0.001) as compared to a 70% decrease noted 48 hours after treatment with 40 μM CIG (1987 pg/ml vs. 598 pg/ml, P<0.001). CIG significantly decreased VEGF production by human granulosa cells in an in vitro model. The effect appeared dose related, with the greatest inhibitory response observed when using a 40 μM dose. Given VEGF's pivotal role in the pathogenesis of OHSS, these findings prompt further investigation of thiazolidinedione drugs such as FDA-approved pioglitazone as a novel prophylaxis or therapy for this condition.