Similar PAI-1 expression in visceral and subcutaneous fat of postmenopausal women

Recent studies showed that intraabdominal visceral fat located in the mesenterium and omentum may significantly influence the circulating plasminogen activator inhibitor type 1 (PAI-1). To substantiate this link, we performed analysis of PAI-1 expression in human visceral and subcutaneous adipose tissues in peri- and postmenopausal women. The samples of both visceral and subcutaneous fat from 28 generally healthy women (aged 45-69 years) with a wide range of body mass index (BMI; 22.30-38.67 kg/m2), who underwent surgical operation due to benign ovary and uterine tumours, were obtained. In these samples, expression of mRNAs for PAI-1, tumour necrosis factor alpha (TNFalpha), acyl-CoA synthetase (ACS), and glucose transporter (GLUT-4) was analysed by relative quantitative RT PCR and correlated with plasma PAI-1 antigen. In addition, visceral fat area was measured with computer tomography. Both types of fat tissues contained similar quantities of PAI-1 mRNA, and there was no correlation between plasma PAI-1, measured both by antigen and activity, with either visceral or subcutaneous fat PAI-1 mRNA. Furthermore, there was no significant association between the expression of PAI-1 mRNA and TNFalpha mRNA in tested fat samples. PAI-1 mRNA in both fat tissues was significantly correlated with plasma levels of estradiol (positive correlation) and follicle-stimulating hormone (FSH; negative correlation). Finally, the expression of PAI-1 mRNA was negatively correlated with mRNA of ACS present in both fat tissues. In summary, this study directly indicates that PAI-1 mRNA is similarly expressed in both subcutaneous and visceral fat of peri- and postmenopausal women and its expression strongly depends upon lipid metabolism.