Oxidation modifies the structure and function of the extracellular matrix generated by human coronary artery endothelial cells

Extracellular matrix (ECM) materials such as laminin, perlecan, type IV collagen and fibronectin play a key role in determining the structure of the arterial wall and the properties of cells that interact with ECM. The aim of this study was to investigate the effect of peroxynitrous acid an oxidant generated by activated macrophages, on the structure and function of the ECM laid down by human coronary artery endothelial cells (HCAECs) in vitro and in vivo. It is shown that exposure of HCAEC-derived native matrix components to peroxynitrous acid (but not decomposed oxidant) at concentrations > 1 µM results in a loss of antibody recognition of perlecan, collagen IV and cell binding sites on laminin and fibronectin. Loss of recognition was accompanied by decreased HCAEC adhesion. Real time PCR showed upregulation of inflammation-associated genes, including matrix metalloproteinases (MMP) 7 and 13 as well as down-regulation of laminin-α2 chain, in HCAECs cultured on peroxynitrous acid-treated-matrix compared to native. Immunohistochemical studies provided evidence of co-localisation of laminin with 3-nitrotyrosine, a biomarker of peroxynitrous acid damage, in type II to III/IV human atherosclerotic lesions, consistent with matrix damage occurring during disease development in vivo. These data suggest a mechanism through which peroxynitrous acid modifies EC-derived native ECM proteins of the arterial basement membrane in atherosclerotic lesions. These changes to E...

Source: BJ Energy - February 12, 2014 Category: Biochemistry Authors: C Y. Chuang, G Degendorfer, A Hammer, J M. Whitelock, E Malle, M J. Davies Tags: BJ Energy Source Type: research