Mountain Deidra J H, Singh Mahipal, Menon Bindu, Singh Krishna
Dept. of Physiology, James H. Quillen College of Medicine, East Tennessee State Univ., PO Box 70576, Johnson City, TN 37614, USA.
Am J Physiol Cell Physiol. 2007 Feb;292(2):C867-75. doi: 10.1152/ajpcell.00161.2006. Epub 2006 Sep 20.
Matrix metalloproteinases (MMPs), a family of extracellular endopeptidases, are implicated in angiogenesis because of their ability to selectively degrade components of the extracellular matrix. Interleukin-1beta (IL-1beta), 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-1beta 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-1beta 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-1beta. Gelatin in-gel zymography and Biotrak activity assay demonstrated that IL-1beta increases MMP-2 activity in the conditioned media. IL-1beta activated ERK1/2, JNKs, and protein kinase C (PKC), specifically PKCalpha/beta(1), and inhibition of these cascades partially inhibited IL-1beta-stimulated increases in MMP-2. Inhibition of PKCalpha/beta(1) failed to inhibit ERK1/2. However, concurrent inhibition of PKCalpha/beta(1) and ERK1/2 almost completely inhibited IL-1beta-mediated increases in MMP-2 expression. Inhibition of p38 kinase and nuclear factor-kappaB (NF-kappaB) 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-1beta-stimulated increases in MMP-2 protein levels. Exogenous H(2)O(2) significantly increased MMP-2 protein levels, whereas superoxide generation by xanthine/xanthine oxidase had no effect. This in vitro study suggests that IL-1beta modulates expression and activity of MMP-2 in CMECs.
基质金属蛋白酶（MMPs）是一类细胞外肽酶，因其能够选择性降解细胞外基质成分而与血管生成有关。白细胞介素-1β（IL-1β）在心肌梗死后的心脏中表达增加，在心肌梗死后左心室（LV）重构的病理生理学中起保护作用。在这里，我们研究了IL-1β对心脏微血管内皮细胞（CMECs）中各种血管生成基因表达的影响，并研究了参与MMP-2调节的信号通路。对96个血管生成相关基因的cDNA阵列分析表明，IL-1β调节众多基因的表达，显著增加MMP-2而非MMP-9的表达。RT-PCR和蛋白质印迹分析证实，IL-1β刺激后MMP-2表达增加。明胶凝胶酶谱分析和Biotrak活性测定表明，IL-1β增加了条件培养基中MMP-2的活性。IL-1β激活了ERK1/2、JNKs和蛋白激酶C（PKC），特别是PKCα/β(1)，抑制这些级联反应可部分抑制IL-1β刺激的MMP-2增加。抑制PKCα/β(1)未能抑制ERK1/2。然而，同时抑制PKCα/β(1)和ERK1/2几乎完全抑制了IL-1β介导的MMP-2表达增加。抑制p38激酶和核因子-κB（NF-κB）没有效果。用超氧化物歧化酶（SOD）模拟物MnTMPyP预处理可增加MMP-2蛋白水平，而用SOD和过氧化氢酶模拟物EUK134预处理可部分抑制IL-1β刺激的MMP-2蛋白水平增加。外源性H(2)O(2)显著增加MMP-2蛋白水平，而黄嘌呤/黄嘌呤氧化酶产生的超氧化物则没有影响。这项体外研究表明，IL-1β调节CMECs中MMP-2的表达和活性。
