Abstract-Monocyte chemoattractant protein-1 (MCP-1; CCL2)-mediated inflammation plays a critical role in the development of ischemic heart disease (IHD). However, the gene expression changes caused by signal transduction, triggered by MCP-1 binding to its receptor CCR2, and their possible role in the development of IHD are not understood. We present evidence that MCP-1 binding to CCR2 induces a novel transcription factor (MCP-induced protein [MCPIP]) that causes cell death. Gene microarray analysis showed that when expressed in hiuman embryonic kidney 293 cells, MCPIP induced apoptotic gene families before causing cell death. Mutagenesis studies showed that the structural features required for transcription factor-like activity were also required for causing cell death. Activation of caspase-3 was detected after MCPIP transfection and Z-VAD-fmk partially inhibited cell death. Cardiomyocyte-targeted expression of MCP-1 in mice caused death by heart failure at 6 months of age. MCPIP expression increased in parallel with the development of ventricular dysfunction. In situ hybridization showed the presence of MCPIP transcripts in the cardiomyocytes and immunohistochemistry showed that MCPIP was associated with the cardiomyocyte nuclei of apoptotic cardiomyocytes. CCR2 expression in cardiomyocytes increased with the development of IHD. MCPIP production induced by MCP-1 binding to CCR2 in the cardiomyocytes is probably involved in the development of IHD in this murine model. MCPIP transcript levels were much higher in the explanted human hearts with IHD than with nonischemic heart disease. These results provide a molecular insight into how chronic inflammation and exposure to MCP-1 contributes to heart failure and suggest that MCPIP could be a potential target for therapeutic intervention. nflammation is an important component of cardiovascular pathology associated with a number of types of heart diseases. However, the mechanism by which inflammation contributes to the development of cardiac dysfunction is poorly understood. 1-4 The recruitment and activation of monocytes/macrophages through monocyte chemoattractant protein-1 (MCP-1; CCL2) are thought to be important events that contribute to the initiation and pathophysiology of cardiovascular diseases. 5-7 MCP-1 is the main chemotactic factor for the migration of monocytes/macrophages and the pathogenesis of chronic inflammation. 8,9 Eliminating MCP-1 function or blockade of MCP-1/CCR2 pathway has been shown to decrease neointimal hyperplasia after injury and atherogenesis in mice 10 -14 and attenuate postischemic myocardial remodeling and heart failure. 15 In an attempt to mimic the inflammatory component implicated in the development of cardiovascular diseases, transgenic mice that express MCP-1 specifically in the heart were generated. Cardiactargeted expression of MCP-1 results in monocyte/macrophage infiltration into the heart, and the mice experience a thrombotic occlusive arteriolar vasculopathy that results in ischemia, interstitial fibrosis, ventricular cha...

CeO2 nanoparticles protect against the progression of cardiac dysfunction and remodeling by attenuation of myocardial oxidative stress, ER stress, and inflammatory processes probably through their autoregenerative antioxidant properties.

Many of the major diseases, including cardiovascular disease, are widely recognized as inflammatory diseases. MCP-1 (monocyte chemotactic protein-1) plays a critical role in the development of cardiovascular diseases. MCP-1, by its chemotactic activity, causes diapedesis of monocytes from the lumen to the subendothelial space where they become foam cells, initiating fatty streak formation that leads to atherosclerotic plaque formation. Inflammatory macrophages probably play a role in plaque rupture and the resulting ischaemic episode as well as restenosis after angioplasty. There is strong evidence that MCP-1 plays a major role in myocarditis, ischaemia/reperfusion injury in the heart and in transplant rejection. MCP-1 also plays a role in cardiac repair and manifests protective effects under certain conditions. Such protective effects may be due to the induction of protective ER (endoplasmic reticulum) stress chaperones by MCP-1. Under sustained ER stress caused by chronic exposure to MCP-1, the protection would break down resulting in the development of heart failure. MCP-1 is also involved in ischaemic angiogenesis. The recent advances in our understanding of the molecular mechanisms that might be involved in the roles that MCP-1 plays in cardiovascular disease are reviewed. The gene expression changes induced by the signalling events triggered by MCP-1 binding to its receptor include the induction of a novel zinc-finger protein called MCPIP (MCP-1-induced protein), which plays critical roles in the development of the pathophysiology caused by MCP-1 production. The role of the MCP-1/CCR2 (CC chemokine receptor 2) system in diabetes, which is a major risk factor for cardiovascular diseases, is also reviewed briefly. MCP-1/CCR2- and/or MCPIP-targeted therapeutic approaches to intervene in inflammatory diseases, including cardiovascular diseases, may be feasible.

Endoplasmic reticulum (ER) stress has been found to be associated with neurodegenerative diseases and diabetes mellitus. Whether ER stress is involved in the development of heart disease is not known. Cardiac-specific expression of monocyte chemoattractant protein-1 (MCP-1) in mice causes the development of ischemic heart disease. Here we report that microarray analysis of gene expression changes in the heart of these transgenic mice revealed that a cluster of ER stress-related genes was transcriptionally activated in the heart during the development of ischemic heart disease. The gene array results were verified by quantitative real-time PCR that showed highly elevated transcript levels of genes involved in unfolded protein response such as ER and cytoplasmic chaperones, oxidoreductases, protein disulfide isomerase (PDI) family, and ER-associated degradation system such as ubiquitin. Immunoblot analysis confirmed the expression of chaperones, PDI, and ubiquitin. Immunohistochemical analyses showed that ER stress proteins were associated mainly with the degenerating cardiomyocytes. A novel ubiquitin fold modifier (Ufm1) that has not been previously associated with ER stress and not found to be induced under any condition was also found to be upregulated in the hearts of MCP mice (transgenic mice that express MCP-1 specifically in the heart). The present results strongly suggest that activation of ER stress response is involved in the development of ischemic heart disease in this murine model.

Angiogenesis, the formation of new blood vessels from preexisting vessels in adult tissue, is a key process involved in inflammatory diseases such as diabetes, ischemic heart, and limb diseases and tumor growth (1, 2). Although the critical initiating event for the generation of new blood vessels has been attributed to the production of growth factors, recruitment of monocytes has been suggested to be important in the angiogenic cascade (3, 4). Accumulation of leukocytes at the inflammatory sites is regulated by chemotactic small molecular weight proteins called chemokines. Monocyte chemotactic protein-1 (MCP-1), 2 a key CC chemokine responsible for trafficking and activation of monocytes/macrophages through its receptor CCR2, has been implicated in inflammation and angiogenesis (5, 6). Administration of exogenous MCP-1 has been shown to increase monocyte/macrophage recruitment, collateral vessel formation, and blood flow to the ischemic tissue in hindlimb models of ischemia (6 -8). By drilling tunnels through myocardial tissue, monocytes/macrophages were reported to increase angiogenesis in ischemic myocardium (9). MCP-1 can also directly act on endothelial cells (ECs) to induce angiogenesis (10, 11). However, the mechanisms by which MCP-1 mediates these effects on angiogenesis are unclear.We recently identified a novel transcription factor, designated MCP-1-induced protein (MCPIP), which was originally found in human monocytes after treatment with MCP-1 and is proapoptotic (12). MCP-1 induces this transcription factor, which in turn up-regulates members of the apoptotic gene family that have been linked to angiogenesis and vascular remodeling (13-15). Therefore, it appeared possible that MCP-1-induced angiogenesis might be mediated by transcription factor MCPIP. Here, we report that MCP-1 treatment of human umbilical vein endothelial cells (HUVECs) resulted in induction of MCPIP and that expression of MCPIP enhanced endothelial cell apoptosis, proliferation, migration, and expression of angiogenesis-related genes, resulting in capillary-like tube formation. All of these angiogenic effects of MCP-1 and expression of MCPIP were inhibited by MCPIP-specific small interfering RNA (siRNA). The chromatin immunoprecipitation assay revealed that cadherin (cdh)12 and cdh19 were in vivo targets of MCPIP. Knockdown of MCPIP expression significantly reduced transcript levels of cdh12 and cdh19. Moreover, knockdown of either cdh12 or cdh19 expression inhibited MCPIP-induced capillary-like tube formation. These results strongly suggest that MCP-1-induced angiogenesis is mediated via induction of MCPIP, the newly discovered transcription factor, at least in part through transcriptional activation of cdh12 and cdh19 that have not previously been implicated in angiogenesis. EXPERIMENTAL PROCEDURESCell Culture Conditions-The HUVECs (Clonetics) were grown in endothelial cell basal medium supplemented with hydrocortisone (1 g/ml), bovine brain extract (12 g/ml), gen-* This work was supported, in whole or in part, by National Insti...