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)

Discoidin domain receptors 1 and 2 (DDR1 and DDR2) are tyrosine kinase receptors activated by triple-helical collagens. Aberrant expression and signaling of these receptors have been implicated in several human diseases linked to accelerated matrix degradation and remodeling including tumor invasion, atherosclerosis and liver fibrosis. The objective of this study is to characterize the collagen-binding sites in the discoidin domains of DDR1 and DDR2 at a molecular level. We expressed glutathione S-transferase fusion proteins containing the discoidin and extracellular domains of DDR1 and DDR2 in insect cells and subjected them to a solid-phase collagen-binding assay. We found high affinity binding of the DDR extracellular domains to immobilized type I collagen and confirmed the discoidin-collagen interaction with an enzyme-linked immunosorbent assay-based read-out. Furthermore, we created a three-dimensional model of the DDR1 discoidin domain based on the related domains of blood coagulation factors V and VIII. This model predicts the presence of four neighboring, surface-exposed loops that are topologically equivalent to a major phospholipid-binding site in factors V and VIII. To test the involvement of these loops in collagen binding, we mutated individual amino acid residues to alanine or deleted short sequence stretches within these loops. We found that several residues within loop 1 (Ser-52-Thr-57) and loop 3 (Arg-105-Lys-112) as well as Ser-175 in loop 4 are critically involved in collagen binding. Our structure-function analysis of the DDR discoidin domains provides new insights into this non-integrin-mediated collagen-signaling mechanism and may ultimately lead to the design of small molecule inhibitors that interfere with aberrant DDR function.
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PMID:Exploring the collagen-binding site of the DDR1 tyrosine kinase receptor. 1513 80

Breakdown of triple-helical interstitial collagens is essential in embryonic development, organ morphogenesis and tissue remodelling and repair. Aberrant collagenolysis may result in diseases such as arthritis, cancer, atherosclerosis, aneurysm and fibrosis. In vertebrates, it is initiated by collagenases belonging to the matrix metalloproteinase (MMP) family. The three-dimensional structure of a prototypic collagenase, MMP-1, indicates that the substrate-binding site of the enzyme is too narrow to accommodate triple-helical collagen. Here we report that collagenases bind and locally unwind the triple-helical structure before hydrolyzing the peptide bonds. Mutation of the catalytically essential residue Glu200 of MMP-1 to Ala resulted in a catalytically inactive enzyme, but in its presence noncollagenolytic proteinases digested collagen into typical 3/4 and 1/4 fragments, indicating that the MMP-1(E200A) mutant unwinds the triple-helical collagen. The study also shows that MMP-1 preferentially interacts with the alpha2(I) chain of type I collagen and cleaves the three alpha chains in succession. Our results throw light on the basic mechanisms that control a wide range of biological and pathological processes associated with tissue remodelling.
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PMID:Collagenase unwinds triple-helical collagen prior to peptide bond hydrolysis. 1525 88

We describe our experience with intravenous immunoglobulin (IVIg) treatment in fibrotic conditions and our results and experience with the effect of IVIg therapy to prevent metastases in malignancy. We have delineated the mechanisms by which IVIg can affect atherosclerosis (i.e., effect on MMP-9, antiidiotypes to anti-OxLDL), which led to reduced atherosclerosis in animal models. The effect of IVIg on skin fibrosis was assessed in a murine model of scleroderma-like disease. Collagen expression was decreased in the skin of mice treated with mouse IVIg, associated with decreased type I collagen gene expression, and accompanied by inhibition of transforming growth factor (TGF)beta and interleukin (IL)-4 secretion by splenocytes. We also described a favorable response to IVIg treatment in patients with either systemic sclerosis or myelofibrosis. The administration of IVIg to mice inoculated with melanoma or sarcoma cells induced a statistically significant inhibition of metastatic lung foci and prolongation of survival time. IVIg was found to stimulate the production of IL-12, an anti-tumor and anti-angiogenic cytokine. Positive staining of the cytoplasm, cell membrane, and nuclear membrane of several types of malignant tumors by IVIg was immunohistochemically demonstrated.
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PMID:Intravenous immunoglobulin treatment for fibrosis, atherosclerosis, and malignant conditions. 1558 34

Monocyte chemotactic protein-1 (MCP-1), a potent chemoattractant for monocytes, is thought to play a major role in atherosclerosis, but whether its atherogenic effects involve the direct modulation of vascular smooth muscle cell (SMC) functions remains unclear. This study examined the effects of MCP-1 on the migration of cultured A7r5 SMCs and the signaling pathways involved. Addition of recombinant MCP-1 stimulated SMC migration in modified Boyden chambers coated with type I collagen in a concentration-dependent manner, with 10(-9) M being maximally effective. Using untreated A7r5 cells, two MCP-1 receptors, CCR2 and CCR4, were detected and MCP-1 secretion was significantly increased by stimulation with platelet-derived growth factor. MCP-1-stimulated A7r5 migration was completely blocked by the NAD(P)H oxidase inhibitor, diphenylene iodonium (DPI), and dose-dependently inhibited by polyethylene glycol-conjugated superoxide dismutase (PEG-SOD), suggesting a role for reactive oxygen species (ROS) in this process. During MCP-1 stimulation, ROS production increased rapidly, then gradually decayed over 60 min, and this effect was markedly decreased by pretreatment with DPI or PEG-SOD. Interestingly, U0126 and PD98059, which inhibit activation of extracellular signal-regulated kinases 1/2 (ERK 1/2), significantly inhibited MCP-1-activated ROS generation. Furthermore, transfection of an active mutant of MEK1 (ERK 1/2 kinase) markedly increased superoxide production in rat aortic smooth muscle cells, as detected by dihydroethydium staining, suggesting that ERK 1/2 activation stimulates ROS generation. ERK 1/2 activation was increased for at least 30 min in cells incubated with MCP-1, and this effect was abolished by U0126 or DPI pretreatment. These results demonstrate that MCP-1 is a chemoattractant for SMCs and that MCP-1-stimulated migration requires both ROS production and ERK 1/2 activation in a positive activation loop, which may contribute to the atherogenic effects of MCP-1.
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PMID:Reactive oxygen species and ERK 1/2 mediate monocyte chemotactic protein-1-stimulated smooth muscle cell migration. 1591 91

To elucidate the molecular mechanisms of the cardioprotective effect of angiotensin-converting enzyme (ACE) inhibitors, we evaluated whether the effect of quinapril involved in bradykinin-endothelial nitric oxide synthase (eNOS) and oxidative stress-lectin-like oxidized LDL receptor-1 (LOX-1) pathway. Dahl salt-sensitive hypertensive (DS) rats were fed a diet containing 8% NaCl and treated with one of the following drug combinations for 5 weeks, from 6 weeks of age to left ventricular hypertrophy stage (11 weeks): vehicle; quinapril; quinapril plus the bradykinin B2 receptor antagonist FR172357; the NAD(P)H oxidase inhibitor apocynin; or quinapril plus apocynin. eNOS expression, which was decreased in hypertrophy stage, was significantly increased by quinapril and/or apocynin, but not by quinapril plus FR172357. Upregulated expression of NAD(P)H oxidase p22phox, p47phox, gp91phox and LOX-1 was significantly decreased by quinapril to a similar degree as after treatment with apocynin, but not by quinapril plus FR172357. Quinapril and/or apocynin treatment effectively ameliorated left ventricular weight and vascular changes such as increase in medial thickness and perivascular fibrosis and suppressed expression of transforming growth factor-beta1, type I collagen and fibronectin mRNA, but not that of quinapril plus FR172357. These results suggest that the ACE inhibitor quinapril may have cardioprotective effects in this model of hypertension mediated at least in part through effects on the bradykinin-eNOS and oxidative stress-LOX-1 pathway.
Atherosclerosis 2006 Jul
PMID:Critical role of bradykinin-eNOS and oxidative stress-LOX-1 pathway in cardiovascular remodeling under chronic angiotensin-converting enzyme inhibition. 1621 49

Changes in the collagenous matrix may contribute to the pathogenesis and progression of human aortic valve stenosis (AS). To evaluate the significance of collagen I and III in the pathogenesis of AS, we studied their synthesis in diseased valves. Type I and type III collagen mRNA expression and the immunohistochemical localization of the collagen antigens were studied from 36 AS and 2 normal aortic valves. The concentrations of propeptides and telopeptide structure of type I (PINP, PICP, and ICTP) and those of III collagens (PIIINP and IIINTP) were measured by radioimmunoassays in soluble tissue extracts and trypsin-solubilized calcified and non-calcified matrices of 11 AS and 24 healthy aortic valves of different ages. The synthesis of type I collagen, localized in the myofibroblasts adjacent to calcified nodules, was two- to three-fold in the AS samples compared to the controls. The proportion of collagen in the total protein fraction was 90% in the healthy valves, 50% in the non-calcified matrix, and 10% in the calcified matrix of AS valves. In the calcified valves, the ICTP content was six-fold compared to the age-matched controls and two-fold compared to the young control group. In the controls, the amount of ICTP in type I collagen decreased with age (r=-0.908, p<0.001) and was replaced by other cross-linked C-telopeptide structure. The concentration of type III collagen decreased during aging (r=-0.753, p<0.001). The decrease in total collagen content, despite the increase in type I collagen synthesis indicates an increase in collagen turnover in AS. The calcification of the aortic valves is accompanied by increased amount of ICTP in type I collagen.
Atherosclerosis 2006 Nov
PMID:Type I and type III collagen synthesis and composition in the valve matrix in aortic valve stenosis. 1640 93

Plaque disruption with subsequent thrombus formation is a major cause of atherothrombotic diseases and von Willebrand factor (VWF), which is cleaved by ADAMTS-13, plays a critical role in thrombus formation. However, the role of ADAMTS-13 during thrombogenesis on atherosclerotic vessel remains unknown. We examined the localization of ADAMTS-13 in coronary thrombi obtained from patients with acute myocardial infarction. We also investigated the roles of ADAMTS-13 in thrombus formation using type I collagen-coated flow chambers (100S(-1) and 1500S(-1)) and on injured neointima of rabbit femoral arteries. ADAMTS-13 was present in thrombi of human coronary arteries, where it co-localized with VWF. In a flow chamber, both the average of the surface covered by platelet adhesion and the long axes of platelet thrombi were significantly augmented by an antibody to the ADAMTS-13 disintegrin-like domain (WH2-22-1A) at a shear rate of 1500s(-1), but not by an antibody to the ADAMTS-13 thrombospondin 1-3 domain (WH10). WH2-22-1A also reduced the activity of plasma ADAMTS-13 to cleave large VWF multimers during perfusion. Thrombi on injured neointima were induced by repeated balloon injury of rabbit femoral arteries, and were composed of platelet and fibrin, like human coronary thrombi. WH2-22-1A significantly augmented thrombus formation on injured neointima. These results suggest that the disintegrin-like domain of ADAMTS-13 functions in attenuating thrombus growth on diseased arteries exposed to a high shear rate.
Atherosclerosis 2009 Apr
PMID:ADAMTS-13 attenuates thrombus formation on type I collagen surface and disrupted plaques under flow conditions. 1880 85

Periodontitis is a bacterium-induced chronic inflammation that destroys tissues that attach teeth to jaw bone. Pathologically excessive matrix metalloproteinase 8 (MMP-8) is among the key players in periodontal destruction by initiating type I collagen degradation. We studied MMP-8 in Porphyromonas gingivalis-induced periodontitis by using MMP-8-deficient (MMP8(-/-)) and wild-type (WT) mice. Alveolar bone loss, inflammatory mediator expression, serum immunoglobulin, and lipoprotein responses were investigated to clarify the role of MMP-8 in periodontitis and systemic inflammatory responses. P. gingivalis infection induced accelerated site-specific alveolar bone loss in both MMP8(-/-) and WT mice relative to uninfected mice. The most extensive bone degradation took place in the P. gingivalis-infected MMP8(-/-) group. Surprisingly, MMP-8 significantly attenuated (P < 0.05) P. gingivalis-induced site-specific alveolar bone loss. Increased alveolar bone loss in P. gingivalis-infected MMP8(-/-) and WT mice was associated with increase in gingival neutrophil elastase production. Serum lipoprotein analysis demonstrated changes in the distribution of high-density lipoprotein (HDL) and very-low-density lipoprotein (VLDL) particles; unlike the WT mice, the MMP8(-/-) mice underwent a shift toward a smaller HDL/VLDL particle sizes. P. gingivalis infection increased the HDL/VLDL particle size in the MMP8(-/-) mice, which is an indicator of lipoprotein responses during systemic inflammation. Serum total lipopolysaccharide activity and the immunoglobulin G-class antibody level in response to P. gingivalis were significantly elevated in both infected mice groups. Thus, MMP-8 appears to act in a protective manner inhibiting the development of bacterium-induced periodontal tissue destruction, possibly through the processing anti-inflammatory cytokines and chemokines. Bacterium-induced periodontitis, especially in MMP8(-/-) mice, is associated with systemic inflammatory and lipoprotein changes that are likely involved in early atherosclerosis.
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PMID:Local and systemic responses in matrix metalloproteinase 8-deficient mice during Porphyromonas gingivalis-induced periodontitis. 1902

Although it has been demonstrated that statins stabilize atherosclerotic lesions in animal models of advanced atherosclerosis, there is little evidence to suggest that statins have a preventive effect on plaque rupture itself. In the present study, we examined the effect of fluvastatin on plaque disruption using a simple and quick method of plaque disruption in carotid artery lesions in apolipoprotein E-deficient mice. Male apolipoprotein E-deficient mice received normal chow and underwent ligation of the left common carotid artery just proximal to its bifurcation. Four weeks later, a polyethylene cuff was placed around the artery immediately proximal to the ligation site. Fluvastatin (10mg/kg per day) was given by oral gavage every day starting at 3 days before cuff placement. The administration of fluvastatin suppressed atherosclerotic plaque disruption accompanied by luminal thrombi by 31.5% compared with controls at 4 days after the cuff was placed at the ligated carotid artery. Fluvastatin administration decreased matrix metalloproteinase-9 expression, gelatinolytic activity, endothelial adhesion molecules expression and neutrophil infiltration, and increased type I collagen content in the cuffed region. In summary, fluvastatin was found to prevent plaque disruption through pleiotropic effect on acute inflammation in an animal model using apolipoprotein E-deficient mice.
Atherosclerosis 2009 Oct
PMID:Statin prevents plaque disruption in apoE-knockout mouse model through pleiotropic effect on acute inflammation. 1956 Jan 47

Tobacco smoking is responsible for death of many people each year and increases the risk of developing numerous disorders, particularly cardiovascular disease and cancer. Among the components of cigarette smoke, nicotine is known to excert proatherosclerotic, prothrombotic and proangiogenic effects on vascular endothelial cells. The current study was designed to investigate the mechanisms by which nicotine induces endothelial dysfunction and further to examine whether melatonin protects against nicotine-induced vasculopathy. Four groups of male rats (controls, melatonin-treated, nicotine treated [100 microg/mL in drinking water], and nicotine plus melatonin [5 mg/kg/day] treated) were used in this study. After 28 days all the animals were killed by decapitation and the aorta was removed. We evaluated the hydroxyproline content, and the different expression of proteins involved in several types of stress (ERK1/2), in fibrosis (TGF-beta1, NF-kappaB) and in recruitment of circulating leukocytes onto the vessel wall, including intercellular adhesion molecule-1 (ICAM-1) and vascular cellular adhesion molecule-1 (VCAM-1). These metabolic pathways are important in the development of nicotine-induced atherosclerosis and hypertension. Our results show that nicotine induces marked structural and functional alterations in the aorta. Nicotine receptor binding results in activation and phosphorylation of ERK 1/2. This enzyme, in turn, activates both TGF-beta1 and NF-kappaB; they stimulate respectively the synthesis of type I collagen, responsible of fibrosis, and moreover ICAM-1, VCAM-1 and reactive oxygen species. Based on these findings, melatonin is able to minimize the negative effects of nicotine by blocking the activation of ERK and the other signalling pathways in which this enzyme is involved.
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PMID:Beneficial effects of melatonin on nicotine-induced vasculopathy. 2005 Sep 89


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