Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human umbilical vein endothelial cells can be serially passaged by supplementing medium with a partially purified growth factor. Cell-substratum detachment of early and late passage endothelial cells was examined using trypsin, collagenase, or homocysteine. Late-passage cells detached more rapidly than early passage cells under all conditions tested. The rate of detachment was dependent upon the specific agent used. Protease-mediated detachment was most rapid, occurring over minutes, in contrast to homocysteine-induced detachment, which occurred over hours. When detached cells were collected and replated in the absence of the detaching agent, these cells reattached, spread, and continued to proliferate. No significant difference was observed in the rate of adhesion of either early or late passage cells to a gelatin matrix. When early or late-passage endothelial cells were plated and grown to confluence on a matrix synthesized by the opposite cell type, the rate of protease-mediated cell detachment resembled the cell type from which the matrix was derived. The ease of endothelial cell detachment was determined by the origin of the extracellular matrix. Examination of the extracellular matrices from early and late passage cells revealed significant differences in the amounts of glycosaminoglycans and sulfated proteins present. These studies demonstrate the importance of the endothelial cell extracellular matrix in protease-mediated cell detachment. The rate of cell detachment was controlled by the extracellular matrices are not altered by the endothelial cells.
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PMID:The effect of the extracellular matrix on the detachment of human endothelial cells. 609 97

A number of nutrients and chemicals have now been identified as consistent inducers of tibia dyschondroplasia (TD). Thiram, Antabuse, and fusarochromanone induce TD when fed at 30 to 75 ppm. Cysteine, cystine, homocysteine, and histidine induced TD when fed at .5 to 3% of the diet. Cation: anion imbalances resulting in acidotic diets also induced TD. Even though prevention of TD induced by these chemicals and nutrients has been established, reversal of the spontaneous TD lesion has not been clearly demonstrated. Thus, the etiology of the spontaneous lesion awaits elucidation. These model systems all suggest that TD is the result of decreased growth plate cartilage degradation. Recent work has shown that increased collagen cross-links in the accumulated cartilage, which makes collagen less susceptible to degradation. Cysteine-induced TD seems to decrease growth plate collagenase activity and production. A role of growth plate macrophages in paracrine signaling of collagenase production by chondrocytes has been presented.
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PMID:Factors influencing growth plate cartilage turnover. 807 34

Hyperhomocyst(e)inemia in patients with coronary and peripheral arterial occlusion has been demonstrated by others. Redox-state of homocyst(e)ine causes dysfunction of endothelial cells and promote growth of vascular smooth muscle cells. The role of tissue, protein bound and unbound, oxidative mixed disulfides in the development of fibrous plaque in atherosclerotic lesion is not known. Redox-state around the fibroblasts and vascular smooth muscle cells modulates the expression of extracellular matrix (ECM) components (Tyagi et al. 1996, J Cell Biochem, 61: 139-151). To determine the role of tissue homocystine in fibrotic atherosclerotic plaque development, coronary arteries were isolated from ischemic explanted hearts (n = 10). Apparently normal vascular tissue was obtained from idiopathic cardiomyopathic explanted hearts (n = 10). Tissue extract were prepared from atherosclerotic lesions and from normal arteries devoid of adventitia. Interaction of homocystine with Ellman's reagent (5, 5'-dithio-bis-2-nitro benzoic acid) catalyzed by limiting amount of reducing agent (catalyst) generated change in optical density (OD) at 412 nm in dose dependent fashion. We have generated a standard curve between change at 412 nm and amount of homocystine. The change in OD at 412 nm with increasing amount (0-25 microg) of homocystine demonstrated linearity. The protein-bound oxidized disulfides were precipitated by trichloroacetic acid (TCA) and free-oxidative disulfides in the supernatant were collected. The pathophysiological amount of protein-bound disulfide in atherosclerotic tissue (1.0 +/- 0.2 microg/mg total protein) was 10 times that in normal tissue (0.1 +/- 0.01 microg/mg, p < 0.001). The amount of free oxidative disulfide in atherosclerotic tissue (1.5 +/- 0.3 microg/mg) was 15 times that in normal tissue (0.12 +/- 0.02 microg/mg, p < 0.001). To determine the role of homocystine in ECM expression, ECM collagenase activity in the presence and absence of homocystine was measured by zymography. The effect of homocysteine on collagenase activity was biphasic, increased at < [0.01 mM] and inhibited at > [0.1 mM]. To determine whether homocystine regulates vascular tone, isometric measurements were carried out using normal coronary rings. Results suggested that homocystine induced endothelial-modulated vasoconstriction in coronary vessels. Tissue oxidative disulfides and the homocystine may contribute to the development of fibrotic atherosclerotic lesions and vascular dysfunction.
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PMID:Reduction-oxidation (Redox) and vascular tissue level of homocyst(e)ine in human coronary atherosclerotic lesions and role in extracellular matrix remodeling and vascular tone. 956 47

Alcoholic liver disease is a major cause of illness and death in the United States. In the initial stages of the disease, fat accumulation in hepatocytes leads to the development of fatty liver (steatosis), which is a reversible condition. If alcohol consumption is continued, steatosis may progress to hepatitis and fibrosis, which may lead to liver cirrhosis. Alcoholic fatty liver has long been considered benign; however, increasing evidence supports the idea that it is a pathologic condition. Blunting of the accumulation of fat within the liver during alcohol consumption may block or delay the progression of fatty liver to hepatitis and fibrosis. To achieve this goal, it is important to understand the underlying biochemical and molecular mechanisms by which chronic alcohol consumption leads to fat accumulation in the liver and fatty liver progresses to hepatitis and fibrosis. In addition to alcohol consumption, dietary fatty acids and obesity have been shown to affect the degree of fat accumulation within the liver. Again, it is important to know how these factors modulate the progression of alcoholic liver disease. The National Institute on Alcohol Abuse and Alcoholism and the Office of Dietary Supplements, National Institutes of Health, sponsored a symposium on "Role of Fatty Liver, Dietary Fatty Acid Supplements, and Obesity in the Progression of Alcoholic Liver Disease" in Bethesda, Maryland, USA, October 2003. The following is a summary of the symposium. Alcoholic fatty liver is a pathologic condition that may predispose the liver to further injury (hepatitis and fibrosis) by cytochrome P450 2E1 induction, free radical generation, lipid peroxidation, nuclear factor-kappa B activation, and increased transcription of proinflammatory mediators, including tumor necrosis factor-alpha. Increased acetaldehyde production and lipopolysaccharide-induced Kupffer cell activation may further exacerbate liver injury. Acetaldehyde may promote hepatic fat accumulation by impairing the ability of peroxisome proliferator-activated receptor alpha to bind DNA, and by increasing the synthesis of sterol regulatory binding protein-1. Unsaturated fatty acids (corn oil, fish oil) exacerbate alcoholic liver injury by accentuating oxidative stress, whereas saturated fatty acids are protective. Polyenylphosphatidylcholine may prevent liver injury by down-regulating cytochrome P450 2E1 activity, attenuating oxidative stress, reducing the number of activated hepatic stellate cells, and up-regulating collagenase activity. Nonalcoholic steatohepatitis may develop through several mechanisms, such as oxidative stress, mitochondrial dysfunction and associated impaired fat metabolism, dysregulated cytokine metabolism, insulin resistance, and altered methionine/S-adenosylmethionine/homocysteine metabolism. Obesity (adipose tissue) may contribute to the development of alcoholic liver disease by generating free radicals, increasing tumor necrosis factor-alpha production, inducing insulin resistance, and producing fibrogenic agents, such as angiotensin II, norepinephrine, neuropeptide Y, and leptin. Finally, alcoholic fatty liver transplant failure may be linked to oxidative stress. In vitro treatment of fatty livers with interleukin-6 may render allografts safer for clinical transplantation.
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PMID:Role of fatty liver, dietary fatty acid supplements, and obesity in the progression of alcoholic liver disease: introduction and summary of the symposium. 1567 Jun 59

Accumulation of interstitial collagen (fibrosis) between the endothelium and myocytes is one of the hallmarks of cardiac failure in renovascular hypertension (RVH). Renal insufficiency increases plasma homocysteine (Hcy), and levels of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) are inversely related to plasma Hcy levels. We hypothesize that in RVH, accumulation of collagen between the endothelium and myocytes leads to endothelial-myocyte disconnection and uncoupling, in part, by hyperhomocysteinemia. Furthermore, we hypothesize that Hcy increases reactive oxygen species, generates nitrotyrosine, activates latent matrix metalloproteinase, and decreases the levels of endothelial nitric oxide in response to antagonizing PPAR-gamma. To create RVH in mice, the left renal artery was clipped with 0.4-mm silver wire for the 2 kidney, 1 clip (2K1C) method. Sham surgery was used as a control. To induce PPAR-gamma, 8 microg/mL ciglitazone (CZ) was administered to drinking water 2 days before surgery and continued for 4 weeks. Mice were grouped as 2K1C, sham, 2K1C+CZ, or sham+CZ (n = 6 in each group). Plasma Hcy increased 2-fold in the 2K1C-treated group (p < 0.05) as compared with the sham, and CZ had no effect on Hcy levels as compared to the 2K1C-treated group. Hcy binding in cardiac tissue homogenates decreased in the 2K1C-treated group but was substantially higher in the CZ-treated group. Cardiac reactive oxygen species levels were increased and endothelial nitric oxide were decreased in the 2K1C-treated group. Matrix metalloproteinase-2 and -9 activities were increased in the 2K1C-treated group compared with the control. Levels of cardiac inhibitor of metalloproteinase were decreased, whereas there was no change in tissue inhibitor of metalloproteinase-1 expression in the 2K1C-treated group vs. the sham-treated group. Collagen and nitrotyrosine levels were increased in the 2K1C-treated group, but mice treated with CZ showed lower levels comparatively. Cardiac transferase deoxyuridine nick-end labeling-positive cells were increased, and muscle cells were impaired in the 2K1C-treated mice vs. the sham-control mice. This was associated with decreased acetylcholine and bradykinin responses, which suggests endothelial-myocyte uncoupling in 2K1C-treated mice. Our results suggest that fibrosis between the endothelium and myocytes leads to an endothelial-myocyte disconnection and uncoupling by Hcy accumulation secondary to increased reactive oxygen species, nitrotyrosine, matrix metalloproteinase, and decreased endothelial nitric oxide in response to antagonizing PPAR-gamma.
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PMID:Homocysteine-dependent cardiac remodeling and endothelial-myocyte coupling in a 2 kidney, 1 clip Goldblatt hypertension mouse model. 1609 84

Ceramide-activated NAD(P)H oxidase has been reported to participate in homocysteine (Hcys)-induced abnormal metabolism of the extracellular matrix (ECM) in rat glomerular mesangial cells. However, it remains unknown whether this ceramide-redox signaling pathway contributes to glomerular injury induced by hyperhomocysteinemia (hHcys) in vivo. The present study was designed to address this question, defining the role of ceramide and activated NAD(P)H oxidase in the development of hHcys-induced glomerular injury. Uninephrectomized Sprague-Dawley rats were fed a folate-free diet for 8 weeks to produce hHcys and the de novo ceramide synthesis inhibitor myriocin or the NAD(P)H oxidase inhibitor apocynin was administrated. Rats with folate-free diet significantly increased plasma Hcys levels, renal ceramide levels, and NAD(P)H oxidase activity accompanied by marked glomerular injury. Treatment of rats with myriocin significantly reduced ceramide levels and improved glomerular injury, as shown by decreased urinary albumin excretion and reduced glomerular damage index. ECM components changed towards to normal levels with decreased tissue inhibitor of metalloproteinase-1 and increased matrix metalloproteinase-1 activity. NAD(P)H oxidase activity and Rac GTPase activity were reduced by 69 and 66%, respectively. In rats treated with apocynin, similar beneficial effects in protecting glomeruli from hHcys-induced injury were observed. These results support the view that de novo ceramide production is involved in Hcys-induced NAD(P)H oxidase activity in the kidney of hHcys rats and indicate the important role of ceramide-mediated redox signaling in hHcys-induced glomerular injury in rats.
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PMID:Inhibition of ceramide-redox signaling pathway blocks glomerular injury in hyperhomocysteinemic rats. 1668 15

Hyperhomocysteinemia is widely recognized as an independent risk factor for coronary artery vascular disease, although the underlying mechanisms are not well understood. This study aims to investigate the effect of homocysteine on nitric oxide (NO) production in coronary microvascular endothelial cells (CMECs) and putative mechanisms mediating this effect. CMECs were isolated on Langendorff system by collagenase perfusion of hearts from male rats and cultured. The effect of homocysteine (0.01 to 1 mM) on basal and stimulated NO production was evaluated by measuring nitrite in the culture media after incubation with or without N(G)-nitro-L-arginine methyl ester (L-NAME) (1 mM), superoxide dismutase (100 U/mL), or catalase (1000 U/mL) for 24 h. Total nitrite was measured using Griess reaction after reduction of nitrate to nitrite with nitrate reductase. Homocysteine did not affect basal nitrite accumulation; however, it significantly increased the nitrite accumulation induced by the calcium ionophore A23187 or interleukin-1beta only at 1 mM. This effect of homocysteine was significantly inhibited by L-NAME, superoxide dismutase, and catalase. In conclusion, homocysteine increases NO release from stimulated CMECs without affecting basal NO production, which is probably accompanied by increased production of reactive oxygen species. It can be postulated that endothelial cells generate NO in order to minimize the damage caused by homocysteine.
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PMID:Effect of homocysteine on nitric oxide production in coronary microvascular endothelial cells. 1757 10

We hypothesized that matrix metalloproteinase (MMP)-2, -9, and tissue inhibitor metalloproteinase-1, -2 (TIMP-1, -2) would be abnormal in diabetes and in acute coronary syndromes (ACS). We measured MMP-2, -9, and TIMP-1, -2 plasma levels in healthy subjects (controls), in type 2 diabetic patients, in nondiabetic patients with ACS (ACS) and in diabetic patients with ACS (DACS). We enrolled 165 controls, 181 diabetic patients, 78 ACS, and 46 DACS. We measured also BMI (body mass index), HbA(1c) (glycated hemoglobin) FPG (fasting plasma glucosa), FPI (fasting plasma insulin), HOMA index (homeostasis model assessment index), SBP (systolic blood pressure), DBP (diastolic blood pressure), TC (total cholesterol), LDL-C (low density lipoprotein cholesterol), HDL-C (high-density lipoprotein cholesterol), Tg (triglycerides), Lp(a) (lipoprotein(a)) PAI-1 (plasminogen activator inhibitor-1), Hct (homocysteine), Fg (fibrinogen), and hs-CRP (high-sensitivity C-reactive protein). A significant increase of BMI was observed in the diabetic group, in ACS and DACS patients compared to controls. A significant increase of SBP and DBP resulted in the diabetic and DACS groups, while only SBP improvement was present in ACS patients with respect to controls. A decrease in SBP and DBP was observed in the ACS group, while SBP variation was present in DACS patients compared to diabetics, and DBP increase was obtained in the DACS group with respect to ACS patients. TC, LDL-C, Tg, and Lp(a) increase was present in diabetics, while TC, Tg, and Lp(a) improvement was present in ACS and DACS patients with a significant decrease of HDL-C levels in diabetic, ACS, and DACS groups compared to controls. A decrease in LDL-C was obtained in ACS and DACS groups, while HDL-C increase was observed in these patients with respect to diabetics. Tg levels were higher in the DACS group compared to diabetics and ACS patients, respectively. Increases in PAI-1, Hct, Fg, and hs-CRP were present in diabetic and DACS groups, while PAI-1, Hct, and hs-CRP improvement was obtained in ACS patients with respect to controls. Higher PAI-1 levels came about in ACS and DACS groups, while HCT and Fg levels were lower in ACS patients compared to diabetics. An increase in Fg was present in the DACS group with respect to ACS patients. A decrease in Hs-CRP was observed in DACS patients compared to diabetics and the ACS group, respectively. Higher MMP-2, MMP-9, TIMP-1, and TIMP-2 levels were present in diabetic, ACS, and DACS patients compared to controls. Significant MMP-2, TIMP-1, and TIMP-2 increases were observed in ACS and DACS groups, while MMP-9 decreased in these patients compared to diabetics. In conclusion, MMP-2, MMP-9, TIMP-1, and TIMP-2 plasma levels were higher in diabetic, ACS, and DACS patients, which may reflect abnormal extracellular matrix metabolism in diabetes and in acute coronary syndrome.
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PMID:Comparison between metalloproteinases-2 and -9 in healthy subjects, diabetics, and subjects with acute coronary syndrome. 1804 92

Matrix metalloproteinases (MMPs), a family of zinc-dependent proteinases, participate in remodeling and degradation of the extracellular matrix proteins. The activity of MMPs is thought to be predominately posttranslationally regulated via proteolytic activation of precursor zymogens or via their naturally occurring endogenous inhibitors. Here, using recombinant MMP-1, we investigated new redox-dependent mechanisms of proteinase activity regulation by low-molecular-weight thiols. We find that glutathione (GSH), cysteine, homocysteine, and N-acetylcysteine at physiological concentrations competitively reduce MMP-1 activity up to 75% with an efficiency of cysteine > or = GSH > homocysteine > N-acetylcysteine. In contrast, S-derivatized thiols completely lack this inhibitory activity. Interestingly, the competitive GSH-mediated inhibition of MMP-1-activity can be fully reversed abrogated by oxidizing radicals like (*)NO(2) or Trolox radicals, here generated by UVA irradiation of nitrite or Trolox, two relevant agents in human skin physiology. This redox-dependent reactivation of the inactive GSH-MMP-1-complex comprises GSH oxidation and is significantly inhibited in the presence of ascorbic acid, an effective (*)NO(2) and Trolox radical scavenger. We here offer a new concept of redox-sensitive control of MMP-1 activity based on the inhibitory effect of reduced thiols and reactivation by a mechanism comprising derivatization or oxidation of the MMP-1-bound inhibitory-acting thiol.
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PMID:A new redox-dependent mechanism of MMP-1 activity control comprising reduced low-molecular-weight thiols and oxidizing radicals. 1903 2

We evaluate the effect of a standardized dietary supplementation with omega-3 polyunsaturated fatty acids (n-3 PUFAs) on the level of some markers of vascular remodeling in patients with combined dyslipidemia. Three hundred and thirty-three patients received placebo or n-3 PUFAs for 6 months. We evaluated body mass index, glycemic profile, blood pressure, lipid profile, lipoprotein(a), plasminogen activator inhibitor-1, homocysteine, fibrinogen, high-sensitivity C reactive protein, ADP, MMP-2 and MMP-9, and tissue inhibitors of metalloproteinase-1 and -2. A significant increase of high-density lipoprotein-cholesterol, and a significant decrease of triglycerides were present after 3 and 6 months with n-3 PUFAs intake. A significant plasminogen activator inhibitor-1, fibrinogen and high-sensitivity C reactive protein decrease was obtained after 3 and 6 months and a significant ADP increase was observed after 3 and 6 months of n-3 PUFAs. A significant MMP-2, MMP-9, tissue inhibitors of metalloproteinase-1 and tissue inhibitors of metalloproteinase-2 decrease was obtained after 6 months compared to the baseline value with n-3 PUFAs intake. n-3 PUFAs give a better lipid profile and a better improvement of coagulation, fibrinolytic and inflammatory parameters than placebo. Furthermore, lowers levels of MMP-2, MMP-9 and their tissue inhibitors are obtained with n-3 PUFAs compared to placebo.
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PMID:Effects of long chain omega-3 fatty acids on metalloproteinases and their inhibitors in combined dyslipidemia patients. 2977 Nov 71


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