The increase in plasminogen activator inhibitor type-1 expression by stimulation of activators for peroxisome proliferator-activated receptors in human endothelial cells.

OBJECTIVE: [corrected] To investigate the effect of peroxisome proliferator-activated receptors (PPARs) activators on plasminogen activator inhibitor type-1 (PAI-1) expression in human umbilical vein endothelial cells and the possible mechanism.
METHODS: Human umbilical vein endothelial cells (HUVECs) were obtained from normal fetus, and cultured conventionally. Then the HUVECs were exposed to test agents (linolenic acid, linoleic acid, oleic acid, stearic acid and prostaglandin J2 respectively) in varying concentrations with fresh media. RT-PCR and ELISA were applied to determine the expression of PPARs and PAI-1 in HUVECs.
RESULTS: PPAR alpha, PPAR beta and PPAR gamma mRNA were detected by using RT-PCR in HUVECs. Treatment of HUVECs with PPARalpha and PPAR gamma activators--linolenic acid, linoleic acid, oleic acid and prostaglandin J2 respectively, but not with stearic acid could augment PAI-1 mRNA expression and protein secretion in a concentration-dependent manner. However, the mRNA expressions of 3 subclasses of PPAR with their activators in HUVECs were not changed compared with controls.
CONCLUSION: HUVECs express PPARs. PPARs activators may increase PAI-1 expression in ECs, but the underlying mechanism remains unclear. Although PPARs expression was not enhanced after stimulated by their activators in ECs, the role of functionally active PPARs in regulating PAI-1 expression in ECs needs to be further investigated by using transient gene transfection assay.