Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It has been suggested that calcium (Ca(2+)) overload and oxidative stress damage the myocardium during ischemia and reperfusion. We investigated the possible effect of varying extracellular Ca(2+)and total cell Ca(2+)on reactive oxygen species (ROS) levels in resting adult rat cardiomyocytes. Cardiomyocytes were isolated by trypsin/collagenase digestion and exposed to 1 h of hypoxia (H) (95% N(2)/5% CO(2), no glucose) and 2 h of reoxygenation (R) (95% air/5% CO(2), glucose 5.5 m M) in suspension. Cell Ca(2+)was measured by uptake of(45)Ca(2+). ROS was measured by flow cytometry of ethidium's red fluorescence formed by oxidation of dihydroethidium mostly by superoxide anion. Cell viability decreased during H and R, expressed as uptake of trypan blue, loss of rod shape morphology and release of lactate dehydrogenase. Rapidly exchangeable cell Ca(2+)was closely correlated with extracellular Ca(2+)concentration. Cell Ca(2+)was unchanged during H but increased three to four times after R. This increase was attenuated by adding 3,4-dichlorobenzamil, 10 microm at R, and amplified by adding ouabain 1 m M (from start), respectively. Levels of ROS in hypoxic cells were unchanged or slightly reduced at the end of H and increased significantly by 20% compared to control after R. Levels of ROS were significantly decreased by lowering total extracellular Ca(2+)from 1 m M to 0.1 m M or by decreasing free extracellular Ca(2+)with EGTA 0.9 m M at the onset of R. Keeping extracellular Ca(2+)constant, ROS levels were neither affected by attenuating the increase in cell Ca(2+)by DCB nor by amplifying the increase in cell Ca(2+)by ouabain. In conclusion, ROS (superoxide anion) levels increase rapidly after reoxygenation, are correlated with extracellular-free Ca(2+)and are reduced by lowering extracellular-free Ca(2+). Levels of ROS are apparently not consistently correlated with total cell Ca(2+).
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PMID:Effect of calcium on reactive oxygen species in isolated rat cardiomyocytes during hypoxia and reoxygenation. 1073 43

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

The clinical use of bioprosthetic heart valves (BHV) is limited due to device failure caused by structural degeneration of BHV leaflets. In this study we investigated the hypothesis that oxidative stress contributes to this process. Fifteen clinical BHV that had been removed for device failure were analyzed for oxidized amino acids using mass spectrometry. Significantly increased levels of ortho-tyrosine, meta-tyrosine and dityrosine were present in clinical BHV explants as compared to the non-implanted BHV material glutaraldehyde treated bovine pericardium (BP). BP was exposed in vitro to oxidizing conditions (FeSO4/H2O2) to assess the effects of oxidation on structural degeneration. Exposure to oxidizing conditions resulted in significant collagen deterioration, loss of glutaraldehyde cross-links, and increased susceptibility to collagenase degradation. BP modified through covalent attachment of the oxidant scavenger 3-(4-hydroxy-3,5-di-tert-butylphenyl) propyl amine (DBP) was resistant to all of the monitored parameters of structural damage induced by oxidation. These results indicate that oxidative stress, particularly via hydroxyl radical and tyrosyl radical mediated pathways, may be involved in the structural degeneration of BHV, and that this mechanism may be attenuated through local delivery of antioxidants such as DBP.
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PMID:The susceptibility of bioprosthetic heart valve leaflets to oxidation. 2436 Jul 21

Bioprosthetic heart valves (BHV) fabricated from glutaraldehyde pretreated heterograft materials, porcine aortic valves or bovine pericardium (BP), are widely used in cardiac surgery. BHV progressively fail in clinical use due to structural degeneration. Previously we reported that dityrosine, an oxidized amino acid, was present in failed clinical BP-BHV explants; unimplanted BP had no detectable dityrosine. In the same studies BP were demonstrated in vitro to be susceptible to oxidative damage, that could be mitigated with BP covalently modified with the antioxidant, 3-(4-hydroxy-3,5-di-tert-butylphenyl)propyl amine (DBP). The present studies compared in rat subdermal implants glutaraldehyde pretreated BP to BP modified with either DBP or the chemical reactions used to link DBP. All BP explants regardless of DBP demonstrated reduced hydroxyproline and increased digestibility by collagenase. However, the DBP-BP explants showed significant inhibition of reduced explant shrink temperatures (an index of crosslinking) as compared with control BP. Significant mitigation of calcification was observed in both the BP-DBP and chemically modified explants as compared with BP. Dityrosine was not detectable in the 90 day explants. It is concluded that rat subdermal BP implants undergo both calcific and noncalcific structural degeneration, but without the formation of dityrosine, unlike clinical BP explants.
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PMID:The effects of the covalent attachment of 3-(4-hydroxy-3,5-di-tert-butylphenyl) propyl amine to glutaraldehyde pretreated bovine pericardium on structural degeneration, oxidative modification, and calcification of rat subdermal implants. 2554 35