Aminaftone, a Derivative of??4-Aminobenzoic Acid, Downregulates??Endothelin-1 Production in??ECV304 Cells

Abstract

Endothelin-1 (ET-1) plays a central role in the pathogenesis of several vascular diseases. Aminaftone is a drug used for the treatment of capillary disorders but which has a mechanism of action that is not fully understood. We investigated whether aminaftone may exert its effect by interfering with the production of ET-1. Human ECV304 endothelial cells were incubated with interleukin-1beta (IL-1beta) 100 IU/mL with or without the addition of increasing concentrations of aminaftone (2, 4 or 6 microg/mL). ET-1 concentrations in surnatants were quantified by enzyme immunoassay kit at 3, 6 and 12 hours. Pre-pro-endothelin-1 (PPET-1) gene expressions were also analysed by real-time polymerase chain reaction (RT-PCR) at the same time points. Endothelin-converting enzyme (ECE) activity was also determined. Incubation with IL-1beta increased concentrations of ET-1 and PPET-1 relative gene expression. Incubation with aminaftone significantly reduced production of ET-1 in a concentration-dependent manner. A strong direct correlation was found between ET-1 concentrations and PPET-1 relative gene expression, but aminaftone did not influence ECE activity. Aminaftone inhibits ET-1 production in cell cultures by interfering with transcription of the PPET-1 gene. These findings may account for the clinical efficacy of aminaftone in the treatment of capillary disorders and may encourage conduct of further clinical trials.