Interleukin-1β increases expression and activity of matrix metalloproteinase-2 in cardiac microvascular endothelial cells:: role of PKCα/β1 and MAPKs

Matrix metalloproteinases ( MMPs), a family of extracellular endopeptidases, are implicated in angiogenesis because of their ability to selectively degrade components of the extracellular matrix. Interleukin1 beta (IL-1 beta), increased in the heart post- myocardial infarction (post-MI), plays a protective role in the pathophysiology of left ventricular ( LV) remodeling following MI. Here we studied expression of various angiogenic genes affected by IL-1 beta in cardiac microvascular endothelial cells ( CMECs) and investigated the signaling pathways involved in the regulation of MMP- 2. cDNA array analysis of 96 angiogenesis- related genes indicated that IL-1 beta modulates the expression of numerous genes, notably increasing the expression of MMP-2, not MMP-9. RT-PCR and Western blot analyses confirmed increased expression of MMP- 2 in response to IL-1 beta. Gelatin in- gel zymography and Biotrak activity assay demonstrated that IL-1 beta increases MMP- 2 activity in the conditioned media. IL-1 beta activated ERK1/2, JNKs, and protein kinase C ( PKC), specifically PKC alpha/beta 1, and inhibition of these cascades partially inhibited IL-1 beta-stimulated increases in MMP-2. Inhibition of PKC alpha/beta(1) failed to inhibit ERK1/ 2. However, concurrent inhibition of PKC alpha/beta(1) and ERK1/2 almost completely inhibited IL-1 beta-mediated increases in MMP- 2 expression. Inhibition of p38 kinase and nuclear factor-kappa B ( NF-kappa B) had no effect. Pretreatment with superoxide dismutase ( SOD) mimetic, MnTMPyP, increased MMP- 2 protein levels, whereas pretreatment with SOD and catalase mimetic, EUK134, partially inhibited IL-1 beta-stimulated increases in MMP- 2 protein levels. Exogenous H2O2 significantly increased MMP- 2 protein levels, whereas superoxide generation by xanthine/xanthine oxidase had no effect. This in vitro study suggests that IL-1 modulates expression and activity of MMP-2 in CMECs.