Nitric Oxide Induces Cardiac Protection by Preventing Extracellular Matrix Degradation through the Complex Caveolin-3/EMMPRIN in Cardiac Myocytes.

Irene Cuadrado,Marta Saura,Carlos Zaragoza,Carlos Zaragoza,Paula Reventun-Torralba,Jose Luis Zamorano,Jose Luis Zamorano,Ana M Martin,Borja Castejon

doi:10.1371/journal.pone.0162912

Abstract

Inhibition of Extracellular Matrix degradation by nitric oxide (NO) induces cardiac protection against coronary ischemia/reperfusion (IR). Glycosylation of Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) stimulates enzymatic activation of matrix metalloproteinases (MMPs) in the heart, although the mechanisms leading to EMMPRIN glycosylation are poorly understood. We sought to determine if NO may induce cardiac protection by preventing glycosylation of EMMPRIN in a mouse model of IR. Here we found that Caveolin-3 binds to low glycosylated EMMPRIN (LG-EMMPRIN) in cardiac cells and in the hearts of healthy mice, whereas IR disrupted the complex in nitric oxide synthase 2 (NOS2) knockout (KO) mice. By contrast, the binding was partially restored when mice were fed with an NO donor (DEA-NO) in the drinking water, showing a significant reduction on infarct size (NOS2KO: 34.6±5 vs NOS2KO+DEA-NO: 20.7±9), in expression of matrix metalloproteinases, and cardiac performance was improved (left ventricular ejection fraction (LVEF). NOS2KO: 31±4 vs NOS2KO+DEA-NO: 46±6). The role of Caveolin-3/EMMPRIN in NO-mediated cardiac protection was further assayed in Caveolin-3 KO mice, showing no significant improvement on infarct size (Caveolin-3 KO: 34.8±3 vs Caveolin-3 KO+DEA-NO:33.7±5), or in the expression of MMPs, suggesting that stabilization of the complex Caveolin-3/LG-EMMPRIN may play a significant role in the cardioprotective effect of NO against IR.

Highlights

matrix metalloproteinases (MMPs) are proteolytic degrading enzymes that cleave extracellular matrix (ECM) components
We found that Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) co-localizes with Caveolin-3 in resting HL1B cardiac myocytes, as detected by confocal microscopy (Fig 2, Control)
We show for the first time that low glycosylated EMMPRIN is bound to Caveolin-3 in WT and nitric oxide synthase 2 (NOS2) KO mice, while the complex was significantly reduced 48 hours after IR in NOS2 KO mice

Summary

Introduction

MMPs are proteolytic degrading enzymes that cleave extracellular matrix (ECM) components. MMP enzymatic activation induces cardiac myocyte necrosis, heart failure, and abnormal ventricular remodeling [1]. The Complex Caveolin-3/EMMPRIN Is a Target of NO in Cardiac Protection. EMMPRIN (CD147, Basigin) regulates the expression of several MMPs, including MMP-2 and MMP9, and it plays a pivotal role in the inflammatory response to ischemia in monocytes and cardiac cells [2, 3]. Caveolae are cholesterol and sphingolipid enriched small vesicles present in the cell membranes of several cell types, including cardiac myocytes [4]. Caveolae harbor many signaling pathways, in which caveolins play a dual role as structural, and regulatory elements through protein-protein interaction with resident caveolar proteins [5]. The expression patterns of Caveolin -1, and -2, are distinct from that of Caveolin-3, the later limited to smooth, skeletal and cardiac muscle [6]

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