Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The migration and proliferation of vascular smooth muscle cells (SMCs) during neointima formation in atherosclerosis and angioplasty restenosis is mediated by certain growth factors and cytokines, one action of which may be to promote basement-membrane degradation. To test this hypothesis further, the effects of such growth factors and cytokines on the synthesis of two basement-membrane-degrading metalloproteinases, namely the 72 kDa gelatinase (MMP-2, gelatinase A) and the 95 kDa gelatinase (MMP-9, gelatinase B) and three tissue inhibitors of metalloproteinases (TIMPs) was studied in primary cultured rabbit aortic SMCs. Expression of the 95 kDa gelatinase was increased by phorbol myristate acetate, foetal calf serum, thrombin and interleukin-1alpha (IL-1alpha); platelet-derived growth factor (PDGF) BB alone had no effect but acted synergistically with IL-1alpha. A selective protein kinase C inhibitor, Ro 31-8220, abolished induction of the 95 kDa gelatinase. In contrast, none of the agents tested modulated the synthesis of the 72 kDa gelatinase. We conclude that maximal up-regulation of 95 kDa gelatinase expression requires the concerted action of growth factors and inflammatory cytokines mediated, in part, by a protein kinase C-dependent pathway. TIMP-1 and TIMP-2 were highly expressed, and their synthesis was not affected by growth factors or cytokines. Expression of TIMP-3 mRNAs was, however, increased by PDGF and transforming growth factor beta, especially in combination. Divergent regulation of gelatinase and TIMP expression implies that either net synthesis or net degradation of basement membrane can be mediated by appropriate combinations of growth factors and cytokines.
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PMID:Divergent regulation by growth factors and cytokines of 95 kDa and 72 kDa gelatinases and tissue inhibitors or metalloproteinases-1, -2, and -3 in rabbit aortic smooth muscle cells. 867 Jan 28

Degradation of the extracellular basement membrane is implicated in atherosclerosis, restenosis after angioplasty, and intimal thickening of vein grafts. Upregulation of metalloproteinase (MMP)-2 and MMP-9 accompanies neointima formation in cholesterol-fed rabbits, in rat and pig models of angioplasty, and in organ cultures of human saphenous veins. MMPs are inhibited by binding to tissue inhibitors of MMPs (TIMPs). Relatively little is known about their regulation in relationship to neointima formation; thus, we investigated TIMP expression in the organ culture model. Qualitative reverse transcriptase-polymerase chain reaction of mRNA extracted from veins showed that TIMP-1, TIMP-2, and TIMP-3 are each expressed before and after culture. Zymography revealed that TIMP-1 was the most abundant TIMP secreted and that its secretion increased dramatically between 0 to 2 and 12 to 14 days of culture. An enzyme-linked immunosorbent assay showed that TIMP-1 secretion increased from 3.2+/-1.5 (mean+/-SE) to 32+/-6 ng/mg wet weight per day (n=5, P<0.01). Immunocytochemical testing localized the increased expression of TIMP-1 to neointimal smooth muscle cells. Although less abundant, TIMP-2 secretion also increased from 0.8+/-0. 3 to 4.7+/-0.2 ng/mg wet weight per day (n=5, P<0.001), and tissue levels increased from 33+/-7 to 150+/-70 ng/mg wet weight (P<0.05). TIMP-2 was also immunolocalized to neointimal smooth muscle cells and their surrounding matrix. TIMP-3 was not secreted but was detected variably and constitutively in tissue extracts (160+/-120 and 170+/-100 ng/mg wet weight [n=9] on days 2 and 14, respectively). TIMP-3 was found in the cells and extracellular matrix of the media and adventitia before culture and to a lesser extent in the neointima after 14 days of culture. Rates of total TIMP secretion on day 14 exceeded those of MMP-2 and MMP-9 (10.6+/-1.9 and 15.6+/-2.3 ng/mg wet weight per day, respectively). Consistent with this, in situ zymography showed that MMP gelatinase activity was highly localized to cell bodies in the media and neointima. Secretion of TIMP-1 and TIMP-2 is greatly increased during neointima formation in human saphenous veins. TIMP-1 is readily released, whereas TIMP-2 remains partially attached and TIMP-3 exclusively attached to the extracellular matrix. Regulation of TIMP expression is therefore an important determinant of net MMP activity during neointima formation, restricting it to the pericellular environment.
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PMID:Expression of tissue inhibitor of metalloproteinase-1, -2, and -3 during neointima formation in organ cultures of human saphenous vein. 997 5

The matrix metalloproteinases (MMPs) play a key role in the normal physiology of connective tissue during development, morphogenesis and wound healing, but their unregulated activity has been implicated in numerous disease processes including arthritis, tumor cell metastasis and atherosclerosis. An important mechanism for the regulation of the activity of MMPs is via binding to a family of homologous proteins referred to as the tissue inhibitors of metalloproteinases (TIMP-1 to TIMP-4). The two-domain TIMPs are of relatively small size, yet have been found to exhibit several biochemical and physiological/biological functions, including inhibition of active MMPs, proMMP activation, cell growth promotion, matrix binding, inhibition of angiogenesis and the induction of apoptosis. Mutations in TIMP-3 are the cause of Sorsby's fundus dystrophy in humans, a disease that results in early onset macular degeneration. This review highlights the evolution of TIMPs, the recently elucidated high-resolution structures of TIMPs and their complexes with metalloproteinases, and the results of mutational and other studies of structure-function relationships that have enhanced our understanding of the mechanism and specificity of the inhibition of MMPs by TIMPs. Several intriguing questions, such as the basis of the multiple biological functions of TIMPs, the kinetics of TIMP-MMP interactions and the differences in binding in some TIMP-metalloproteinase pairs are discussed which, though not fully resolved, serve to illustrate the kind of issues that are important for a full understanding of the interactions between families of molecules.
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PMID:Tissue inhibitors of metalloproteinases: evolution, structure and function. 1070 63

Matrix metalloproteinases (MMPs) play a central role in many biological processes such as development, morphogenesis and wound healing, but their unbalanced activities are implicated in numerous disease processes such as arthritis, cancer metastasis, atherosclerosis, nephritis and fibrosis. One of the key mechanisms to control MMP activities is inhibition by endogenous inhibitors called tissue inhibitors of metalloproteinases (TIMPs). This review highlights the structures and inhibition mechanism of TIMPs, the biological activities of TIMPs, the unique properties of TIMP-3, and the altered specificity towards MMPs achieved by mutagenesis. A potential therapeutic use of TIMP variants is discussed.
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PMID:Engineering of tissue inhibitor of metalloproteinases mutants as potential therapeutics. 1211 Jan 23

Gene therapy could improve human saphenous vein (HSV) coronary vein-graft patency by reducing early thrombosis, neointimal hyperplasia and atherosclerosis. Mouse and rabbit models use veins with much thinner walls than pig or HSVs but atherosclerosis can be more easily induced; none of these models shows early thrombosis. Prostacyclin synthase, tissue factor pathway inhibitor, and tissue plasminogen activator might decrease thrombus formation. Tissue inhibitors of metalloproteinases (TIMPs) reduce intimal migration of smooth muscle cells, while TIMP-3 and the p53 tumor suppressor protein promote apoptosis. Prostacyclin synthase and nitric oxide synthase, and cell cycle inhibitors, such as E2F decoy oligonucleotides (D-E2F), reduce neointima formation. This might be enough by itself to decrease later atherosclerosis. Alternatively, direct targeting with nitric oxide synthase, decoy adhesion molecules, or interleukin-10 might be possible.
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PMID:Gene therapy for all aspects of vein-graft disease. 1264 67

Activation of inflammatory pathways may contribute to the beginning and the progression of both atherosclerosis and type 2 diabetes. Here we report a novel interaction between insulin action and control of inflammation, resulting in glucose intolerance and vascular inflammation and amenable to therapeutic modulation. In insulin receptor heterozygous (Insr+/-) mice, we identified the deficiency of tissue inhibitor of metalloproteinase 3 (Timp3, an inhibitor of both TNF-alpha-converting enzyme [TACE] and MMPs) as a common bond between glucose intolerance and vascular inflammation. Among Insr+/- mice, those that develop diabetes have reduced Timp3 and increased TACE activity. Unchecked TACE activity causes an increase in levels of soluble TNF-alpha, which subsequently promotes diabetes and vascular inflammation. Double heterozygous Insr+/-Timp3+/- mice develop mild hyperglycemia and hyperinsulinemia at 3 months and overt glucose intolerance and hyperinsulinemia at 6 months. A therapeutic role for Timp3/TACE modulation is supported by the observation that pharmacological inhibition of TACE led to marked reduction of hyperglycemia and vascular inflammation in Insr+/- diabetic mice, as well as by the observation of increased insulin sensitivity in Tace+/- mice compared with WT mice. Our results suggest that an interplay between reduced insulin action and unchecked TACE activity promotes diabetes and vascular inflammation.
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PMID:Timp3 deficiency in insulin receptor-haploinsufficient mice promotes diabetes and vascular inflammation via increased TNF-alpha. 1629 22

Human cytomegalovirus (HCMV) has been suggested to contribute to the development of vascular diseases. Since matrix metalloproteinases (MMPs) have been implicated in atherosclerosis and plaque rupture, we investigated the effect of HCMV infection on MMP expression in human macrophages. We used quantitative real-time PCR, Western blotting, and gelatin zymography to study the expression and activity of MMP-2, -3, -7, -9, -12, -13, and -14 and of tissue inhibitor of metalloproteinase 1 (TIMP-1), -2, -3, and -4. HCMV infection reduced MMP-9 mRNA, protein, and activity levels but increased TIMP-1 mRNA and protein levels. Furthermore, a decrease in MMP-12, MMP-14, TIMP-2, and TIMP-3 mRNA levels could be detected. The MMP-9 and TIMP-1 mRNA alterations required viral replication. MMP-9 mRNA expression was affected by an immediate-early or early viral gene product, whereas TIMP-1 mRNA expression was affected by late viral gene products. We conclude that HCMV infection specifically alters the MMP-9/TIMP-1 balance in human macrophages, which in turn reduces MMP-9 activity in infected cells. Since MMP-9 prevents atherosclerotic plaque development in mice, these results suggest that HCMV may contribute to atherogenesis through specific effects on MMP-9 activity.
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PMID:Infection with human cytomegalovirus alters the MMP-9/TIMP-1 balance in human macrophages. 1894 72

Homeostasis of the extracellular matrix and apoptosis of vascular smooth muscle cells (VSMCs) are key components in the regulation of the stability of atherosclerotic plaques. Here, we demonstrate that peroxisome proliferator-activated receptor (PPAR)delta regulates extracellular matrix synthesis and degradation through transforming growth factor-beta1 and its effector, Smad3. Activation of PPARdelta strongly amplified the expression of types I and III collagen, fibronectin, elastin, and TIMP-3 (tissue inhibitor of metalloproteinases 3), but not of TIMP-1, matrix metalloproteinase-2 or -9. The effect of PPARdelta on the expression of type III collagen was dually regulated by the direct binding of PPARdelta and Smad3 to a direct repeat-1 site and a Smad-binding element, respectively, in the type III collagen gene promoter. The activation of PPARdelta attenuated apoptotic cell death in VSMCs induced by oxidized low-density lipoprotein, and similar antiapoptotic effects were observed on treatment of cells with exogenous type I and/or III collagen. Administration of a PPARdelta ligand GW501516 to mice also suppressed elastase-induced cell death of aortic VSMCs. These results suggest that PPARdelta-induced upregulation of extracellular matrix proteins exerts an antiapoptotic effect, thereby maintaining the stability of atherosclerotic plaques. Specific ligands of PPARdelta may aid in the therapeutic intervention of atherosclerosis by improving plaque stability and patient prognosis.
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PMID:Peroxisome proliferator-activated receptor {delta} regulates extracellular matrix and apoptosis of vascular smooth muscle cells through the activation of transforming growth factor-{beta}1/Smad3. 1946 Oct 48

Differential vascular remodeling is one of the major mechanisms of heterogeneity in atherosclerosis. The structural and functional heterogeneity between arteries and veins determines the degree of vascular remodeling. Matrix metalloproteases (MMPs) and their tissue inhibitors (TIMPs) play key roles in vascular structural and functional remodeling. We hypothesized that the level of blood flow in different arteries and veins caused structural and functional heterogeneity that ultimately determined potential vascular remodeling. To test this hypothesis, in vivo blood flow and blood pressure in the aorta, carotid, femoral artery, and femoral vein was measured in male Sprague-Dawley rats (weight 380-400 gm). Arterial and venous pressures were measured by PE-50 catheter cannulation. Blood flow was measured by a transonic ultrasound system. The aortic arch, femoral and carotid arteries, and abdominal vena cava were isolated to determine the expression of MMP-2, -9, -12, and -13 and TIMP-1, -3, and -4 by Western blot and in gelatin gel zymography. Masson trichrome and van Gieson stains were used to stain the histologic tissue sections. The results revealed that blood flow was higher in the aorta and carotid artery than the femoral artery and vein. MMP-9 and MMP-13 were higher in the carotid artery in comparison with the other blood vessels, while TIMP-3 showed higher expression in the aorta than the arteries. Further, the MMP-9 activity was significantly higher in the carotid artery than in the aorta and femoral artery. There was a higher degree of basement membrane collagen in the femoral artery and therefore a low elastin: collagen ratio, while in the carotid artery a higher level of elastin and, therefore, a high elastin: collagen ratio was found. The results suggested that medial thickness and elastin:collagen ratios had a threshold in blood flow in the range 0.6-2.5 mL/min, which increased robustly if blood flow increased to 2.7 mL/min. This pattern was inverted by the total MMP:TIMP ratio. We conclude that vascular remodeling is a function of rate of blood flow, which would in turn be determined by the amounts of MMPs and their inhibitors present. The study combined the endothelial and dynamic (blood flow/pressure) components that affect medial thickness and elastin: collagen ratios.
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PMID:Blood flow interplays with elastin: collagen and MMP: TIMP ratios to maintain healthy vascular structure and function. 2040 29

The ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) family consists of 19 proteases. These enzymes are known to play important roles in development, angiogenesis and coagulation; dysregulation and mutation of these enzymes have been implicated in many disease processes, such as inflammation, cancer, arthritis and atherosclerosis. This review briefly summarizes the structural organization and functional roles of ADAMTSs in normal and pathological conditions, focusing on members that are known to be involved in the degradation of extracellular matrix and loss of cartilage in arthritis, including the aggrecanases (ADAMTS-4 and ADAMTS-5), ADAMTS-7 and ADAMTS-12, the latter two are associated with cartilage oligomeric matrix protein (COMP), a component of the cartilage extracellular matrix (ECM). We will discuss the expression pattern and the regulation of these metalloproteinases at multiple levels, including their interaction with substrates, induction by pro-inflammatory cytokines, protein processing, inhibition (e.g., TIMP-3, alpha-2-macroglobulin, GEP), and activation (e.g., syndecan-4, PACE-4).
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PMID:The role of ADAMTSs in arthritis. 2120 96


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