176 - Acetylsalicylic Acid Prevents the Pro-Calcific Differentiation of Valvular Interstitial Cells through the Production of Anti-Inflammatory Lipoxins (ID 505)
Abstract
Background and Aims
To date, no pharmacological therapy has proven to slow down the progression of calcific aortic valve disease (CAVD). Our specific aim is to study the effects of acetylsalicylic acid (ASA) and ASA-triggered lipoxins (ATL) on valvular interstitial cells (VIC) calcification.
Methods
A clone of VIC was treated with endotoxin (LPS, 500 ng/ml) to induce the pro-calcific differentiation and with ASA (1 mM and 10 mM). Alkaline phosphatase (ALP) activity and calcium deposition were determined through colorimetric assays. Proteins and RNA were extracted from VIC to perform western blotting (WB) and gene expression analyses (RT-PCR). A RP-HPLC analysis was conducted on the culture medium to assess the production of arachidonic acid metabolites and ATL (15-HETE and 15-epi-LXA4). Lastly, immunohistochemical analysis was performed on human pathological and healthy valves to investigate the expression of FPR2 (ATL receptor).
Results
The treatment of VIC with ASA reduced ALP activity (p<0.001), calcium deposition (p<0.05) and the expression of pro-inflammatory cytokines (IL-6, TNF-α and IL-1β, p<0.001) induced by LPS. Moreover, cells treated with ASA showed an increased production of ATL (p<0.001). We also observed the increase of FPR2 expression in pathological valves and in VIC treated with LPS. Finally, ALP activity significantly decreased in VIC treated with MMK1 (50 µM), a selective agonist for FPR2.
Conclusions
The treatment with ASA inhibits the pro-calcific differentiation of VIC and this effect might be partly due to the action of ATL. The anti-calcific effect of FPR2 activation can offer the opportunity to develop novel therapeutic strategies for CAVD.
