PAI-1 produced ex vivo by human adipose tissue is relevant to PAI-1 blood level

Human adipose tissue has been shown to produce plasminogen activator inhibitor type 1 (PAI-1). However, the importance of adipose tissue in the regulation of the PAI-1 plasma level is not known. The aim of this study was to investigate the relation between the production of PAI-1 by adipose tissue, plasma PAI-1 level, and variables related to the insulin resistance state. The link between the production of PAI-1 inducers such as tumor necrosis factor-alpha and transforming growth factor-beta and the production of PAI-1 by adipose tissue was also evaluated. Blood samples were obtained as soon as possible to the induction of anesthesia from 30 patients undergoing elective abdominoplasty. PAI-1 antigen levels measured in conditioned media after a 19-hour incubation period of adipose tissue explants were significantly correlated with plasma PAI-1 antigen levels (r=0.54, P=0.004) and with systemic lipid parameters such as triglycerides and high density lipoprotein cholesterol (r=0. 46, P=0.014; r=-0.50, P=0.01, respectively) but not with insulinemia and body mass index. PAI-1 production by adipose tissue was correlated with those of TNF-alpha (r=0.5, P=0.01) and TGF-beta (r=0. 53, P=0.007). These results emphasize the role of adipose tissue in determining plasma levels of PAI-1, with a local contribution of TNF-alpha and TGF-beta in PAI-1 production by adipose tissue.