Expression and regulation of adipocyte fatty acid binding protein in granulosa cells and its relation with clinical characteristics of polycystic ovary syndrome

Increased expression of adipocyte fatty acid binding protein (FABP4) is associated with type 2 diabetic, high triglycerides, increased lipid peroxidation, and inflammation markers. To study the expression of FABP4 mRNA in granulosa cells of patients with polycystic ovary syndrome (PCOS) and the impact of testosterone, insulin, and PPAR gamma agonist rosiglitazone on granulosa cells (GCs), and to investigate the relationship of serum FABP4 levels with clinical characteristics in patients with PCOS. The expression of FABP4 mRNA in GCs of patients with PCOS and normal controls were assayed by RT-PCR. We assessed the level of FABP4 mRNA after treatment with testosterone, insulin, and rosiglitazone in GCs from normal controls. Serum FABP4 were assayed from 96 patients with PCOS (obese and nonobese 48 cases, respectively) and 80 healthy normal controls (obese and the nonobese 40 cases, respectively). The expression of FABP4 mRNA was higher in the GCs of PCOS than that of the controls (P < 0.05). FABP4 mRNA expression was up-regulated by testosterone, insulin, and rosiglitazone at different dosages. Serum FABP4 levels were higher in the nonobese PCOS group than that of the nonobese controls (8.9 +/- 5.1 ng/ml vs. 4.8 +/- 0.7 ng/ml), and in the obese PCOS group than that of the obese controls (28.2 +/- 14.0 ng/ml vs. 15.6 +/- 6.6 ng/ml), respectively (P < 0.05). Multiple linear regression analyses showed that serum FABP4 level was independently associated with HOMA-IR, BMI, and testosterone (P < 0.05). Increased FABP4 was related to the clinical characteristics of PCOS.