Lack of pronounced changes in the expression of fatty acid handling proteins in adipose tissue and plasma of morbidly obese humans

BACKGROUND/OBJECTIVES: Fatty acid handling proteins are involved in the process of accumulation of lipids in different fat tissue depots. Thus, the aim of the study was to estimate the expression of both fatty acid transport and binding proteins in the subcutaneous (SAT) and visceral adipose tissue (VAT) of patients with morbid obesity without metabolic syndrome, as well as the plasma concentrations of these transporters. SUBJECTS/METHODS: Protein (Western blotting) and mRNA (Real-time PCR) expression of selected fatty acid handling proteins was assessed in the visceral and subcutaneous adipose tissue of 30 patients with morbid obesity. The control group consisted of 10 lean age-matched patients. Plasma levels of fatty acid protein transporters were also evaluated using ELISA method. Moreover, total plasma fatty acid composition and concentration was determined by gas-liquid chromatography (GLC). RESULTS: Significant increase in fatty acid translocase (FAT/CD36) mRNA (P = 0.03) and plasmalemmal (P = 0.01) expression was observed in VAT of patients with morbid obesity vs. lean subjects together with elevation of lipoprotein lipase (LPL), as well as peroxisome proliferator-activated receptor γ (PPARγ) in both examined compartments of adipose tissue. Moreover, in obese subjects plasma concentration of RBP4 was markedly elevated (P = 0.04) and sCD36 level presented a tendency for an increase (P = 0.08) with concomitant lack of changes in FABP4 concentration (P > 0.05). CONCLUSIONS: Fatty acid transport into adipocytes may be, at least in part, related to the increased expression of FAT/CD36 in the VAT of morbidly obese patients, which is accompanied by augmented expression of LPL, as well as PPARγ. Probably, alternations in plasma concentrations of RBP4 and sCD36 in obese patients are associated with “unhealthy” fat distribution.