Functional analysis of a biflavone, as a novel inhibitor of TRPV4‐dependent macrophages foam cell formation

Abstract

Cardiovascular disease is the number one cause of death in United States, and atherosclerosis, a chronic inflammatory disease, is the most dominant underlying pathology. Macrophages, an essential cell type in atherogenesis, are known to directly respond to changes to their surrounding mechanical environment. As TRPV4 (transient receptor potential channel of the vanilloid subfamily) channels can be sensitized by changes in matrix stiffness, we hypothesize that, TRPV4 may upregulate inflammatory/atherogenic macrophage functions. We performed a high‐throughput screening for antagonists of TRPV4 from a library of 2000 compounds using a fluorometric imaging plate reader (FLIPR)‐based Ca2+ influx assay; we identified ginkgetin, a biflavone, as a novel antagonist to TRPV4. Primary and secondary screening was performed with normal human dermal fibroblasts and mouse bone marrow derived macrophages (BMDMs) to assess the ability of ginkgetin and other candidates to inhibit TRPV4‐elicited Ca2+ influx after TRPV4 activation with its selective agonist GSK1016790. In our hand's, ginkgetin demonstrated an IC50 of 0.5 μM for inhibition of TRPV4‐elicited Ca2+ influx. We show that antagonism of TRPV4 channel by ginkgetin blocks oxidized LDL (oxLDL)‐induced macrophage foam cell formation in a concentration dependent manner. Mechanistically, we show that ginkgetin attenuated oxLDL uptake but not its cell surface binding in BMDMs. Altogether, our results show that ginkgetin is a novel inhibitor of TRPV4‐mediated macrophage foam cell formation by modulating uptake of oxLDL.Support or Funding InformationAHA (13SDG17310007), Startup grant from University of Maryland, NIH (1R01EB024556‐01), and NSF (CMMI‐1662776) grants to Shaik O RahamanThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.