Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent studies suggest that the nature of events leading to the formation, maintenance, and elimination of synapses may be regulated by cascade-type, locally expressed proteases and protease inhibitors acting on adhesive extracellular matrix components. We have identified a molecule in conditioned medium of murine skeletal muscle cells that in molecular weight, target protease inhibition, heparin-binding and cross-reactivity with authenic antisera is similar to the human serine proteinase inhibitor, protease nexin I. Protease nexin I is a 43-50 kDa glycoprotein of the serpin superfamily (arg-serpin class). Purified anti-protease nexin I antibody (anti-47 kDa) stains adult mouse skeletal muscle in discrete foci that precisely superimpose on synaptic neuromuscular junctions. Protease nexin I appears in patches on surfaces of cultured mouse skeletal myotubes, but not on myoblasts. These patches co-localize with acetylcholine receptor clusters and acetylcholinesterase staining during cellular maturation in culture. Evidence that protease nexin I is a synaptic, extracellular antigen is particularly intriguing since it has been shown to be identical, in structure and activity, with a factor released by glial cells, called glia-derived nexin that stimulates mouse neuroblastoma cell neurite outgrowth and inhibits granule cell migration. Protease nexin I inhibits both tumor cell and myoblast plasminogen activator-mediated destruction of extracellular matrix. Thus, such observations as presented in this report provide further evidence for involvement of cascade proteolytic systems, and their post-translational regulation by specific serpins, in the remodeling that occurs in synapse formation and elimination.
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PMID:Plasminogen activators and inhibitors in the neuromuscular system: III. The serpin protease nexin I is synthesized by muscle and localized at neuromuscular synapses. 203 25

Fibrin formed on endothelial cells has previously been shown to have deleterious effects on the cells. Additionally, substances that cause endothelial cell damage have been reported to induce cultured endothelial cells to synthesize prostacyclin and tissue plasminogen activator (t-PA). The present studies were undertaken to determine whether fibrin formed on cultured human umbilical vein endothelial cells would alter synthesis of prostacyclin and t-PA by the cells. Fibrin was found to increase synthesis of both prostacyclin and t-PA in a dose and time dependent manner. Stimulation of prostacyclin synthesis was completely inhibited by indomethacin; partially inhibited by actinomycin D, cycloheximide, and trifluoperazine; and not affected by cytochalasin D or vinblastine. In contrast, stimulation of t-PA synthesis was completely inhibited by actinomycin D and cycloheximide; partially inhibited by cytochalasin D, vinblastine, and trifluoperazine; and not affected by indomethacin. Fibrin I, formed with Reptilase, caused only slight stimulation of t-PA production, but virtually no stimulation of prostacyclin synthesis. Neither collagen polymerization on the cells nor thrombin added in concentrations that did not induce fibrin polymer formation stimulated production of either substance. Furthermore, soluble fibrin II generated in the presence of the fibrin polymerization inhibitor gly-pro-arg-pro also failed to stimulate either prostacyclin or t-PA production. The presence of platelets in the plasma from which the fibrin was formed did not affect the amount of stimulation of the cells. Fibrin-induced stimulation of endothelial cell production of prostacyclin and t-PA could act to limit vascular occlusion in vivo by inhibiting platelet function and by stimulating fibrinolysis via t-PA.
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PMID:Effect of fibrin on endothelial cell production of prostacyclin and tissue plasminogen activator. 249 87

Purified 2-chain recombinant tissue-type plasminogen activator (t-PA) was reduced under mild conditions - 10 mM dithiothreitol/5 degrees C/1.5 h - and the two chains were separated by chromatography on lysine Sepharose. The t-PA B chain was fully active as determined by its activity towards the chromogenic substrate S-2288 (H-D-ile-pro-arg p-nitroanilide). Analysis by sodium dodecyl sulphate polyacrylamide gel electrophoresis under reducing or non-reducing conditions revealed a single polypeptide at Mr = 35,000 or 29,000 respectively. In addition, under non-reducing conditions a fibrinolytic band at apparent Mr = 29,000 was present after fibrin zymography. The N-terminal sequence was confirmed as ile-lys-gly. The t-PA B chain had a specific amidolytic activity, using S-2288, of 170,000 to 210,000 SU/mg protein. (This compares to a specific activity of the native 2-chain t-PA of 170,000 SU/mg). It resembles urokinase-type plasminogen activator in its inability to be stimulated by fibrin and its dose response on human fibrin plates. However, t-PA B-chain was stimulated to almost the same extent as t-PA by poly-D-lysine. The isoelectric points, at pH 5.6 and 5.7, fall outside the range generally quoted for t-PA preparations (pH 7.8-8.8).
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PMID:Isolation and preliminary characterisation of active B-chain of recombinant tissue-type plasminogen activator. 308 69

Elevated levels of endogenous tissue-type plasminogen activator (t-PA) appear to be a marker for preclinical atherosclerosis. At present, however, data describing potential relations between plasma t-PA level and established lipid risk factors for coronary atherosclerosis are sparse. To explore these potential relations, we measured plasma levels of t-PA antigen (t-PA:ag) in 633 apparently healthy men in the Physicians' Health Study as well as total cholesterol, high-density lipoprotein (HDL) cholesterol, HDL2 cholesterol, HDL3 cholesterol, and apolipoproteins A-I, A-II, and B-100. Overall, plasma t-PA:ag levels were inversely correlated with HDL cholesterol (r = -.1616, P < .0005), HDL2 cholesterol (r = -.1632, P < .0005), and HDL3 cholesterol (r = -.0927, P = .019). In stratified analyses, the inverse association between t-PA:ag and HDL cholesterol was present among frequent (P trend = .002) and infrequent (P trend = .004) consumers of alcohol as well as among the subgroups of frequent exercisers (P trend < .001), men in the lower half of body mass index (P trend = .001), and nonsmokers (P trend < .001). In contrast, there was no association between t-PA:ag and total cholesterol (r = .0219, P = .58), whereas relations of t-PA:ag with apolipoproteins A-I, A-II, and B-100 were minimal and of borderline significance. These data indicate that plasma levels of endogenous t-PA:ag are inversely related to HDL cholesterol as well as HDL2 and HDL3 cholesterol.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A cross-sectional study of endogenous tissue plasminogen activator, total cholesterol, HDL cholesterol, and apolipoproteins A-I, A-II, and B-100. 821 99

The influence of hGH and IGF-I levels on lipid-, lipoprotein metabolism and fibrinolysis were studied in 23 patients with active acromegaly (14 women and 9 men, mean age 49.8 +/- 2.1 years) compared to a sex, BMI and age-matched control group. Mean Lp(a) levels were significantly higher in acromegalics than in controls (469.8 +/- 140.1; n = 23 vs. 162.7 +/- 64.9 mg/l; n = 111; p < 0.01). We found elevated apolipoprotein A-I and Apo E-concentrations in acromegalic patients compared to controls (apo A-I: 1.79 +/- 0.06 vs. 1.46 +/- 0.04 g/l; p < 0.01; apo E: 98.35 +/- 6.4 vs. 72.53 +/- 3.38 mg/l; p < 0.05). 30% of the acromegalics showed increased plasminogen activator inhibitor activity (PAI) while 66% had increased tissue-type plasminogen activator (t-PA) concentrations. There was a correlation between hGH and Lp(a) (r = 0.414; p = 0.05), between hGH and PAI (r = -0.59; p < 0.005) and IGF-I and t-PA activity (r = -0.44; p < 0.05). In a subgroup of nine acromegalics Lp(a) was reduced by 32.2 +/- 6.7% (p < 0.05) after a six-month octreotide therapy and HDL2-cholesterol-concentration increased from 0.17 +/- 0.04 to 0.24 +/- 0.04 mmol/l (p < 0.05). In conclusion, our results demonstrate that elevated Lp(a)-concentrations and changes in fibrinolysis contribute to the cardiovascular complications and should therefore be controlled in acromegalic patients.
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PMID:Anomalies of lipoprotein pattern and fibrinolysis in acromegalic patients: relation to growth hormone levels and insulin-like growth factor I. 943 28

A novel protease with fibrinolytic activity, designated as SW-1, was isolated and purified from the fermentation broth of Streptomyces sp. strain Y405, a soil isolate. The purification procedure involved ammonium sulphate fractionation, decolorization on 290 resin, gel filtration on Sephadex G75, anion-exchange chromatography on DEAE Sephadex A25, and affinity chromatography on Lysine Sepharose 4B. About 4.2 mg purified enzyme was obtained from a liter of fermentation broth and the recovery yield was 12.0%. The purified enzyme showed the specific activity of 2952.3 urokinase units per milligram, which was increased by 230.6 fold over the fermentation broth. The purity determined by HPLC was 83.5%. SW-1 is a single chain polypeptide with a predicted molecular weight of 30 kDa in SDS-PAGE and an isoelectric point of 8.5. The N-terminal sequence of SW-1 is R/N/F-P/D-G-M-T-M-T-A-I-A-N-Q-N-T-Q-I-N. There may be nonhomogeneity in the first and second amino acid residue of its N-terminal sequence. The analysis of amino acid composition showed that SW-1 consisted of 262 amino acids. The fibrinolytic activity of SW-1 was entirely inhibited by 10 mmol/L PMSF, 1 mmol/L EDTA and 1 mol/L lysine, respectively, suggesting that SW-1 is a serine protease and metalloprotease, and that the lysine binding site might play a role in the activity. The fibrinolytic activity of SW-1 is stable between 4-37 degrees C and pH 4.0-9.0, and the optimum pH is 8.0. On plasminogen-free fibrin plates, SW-1 showed the same fibrinolytic activity as the mixture of SW-1 with plasminogen, indicating that SW-1 is a fibrinolytic enzyme which affects fibrin directly, but not a plasminogen activator which affects fibrin by activating plasminogen.
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PMID:Purification and characterization of a novel fibrinolytic enzyme from Streptomyces spp. 1071 27

Tissue-type plasminogen activator (t-PA) is a valuable thrombolytic agent because of its high affinity to fibrin. When produced in mammalian cell lines, it is glycosylated, a modification that is believed to promote its rapid clearance from the circulation. Bacteria such as Escherichia coli have been tested as alternative expression systems but were not able to express the cDNA of t-PA effectively. The coding sequence for t-PA revealed a significant proportion of AGA and AGG codons, which are rarely used in the coding sequences of E. coli. The argU and argW gene products of E. coli proved to be minor tRNA(arg) species, respectively decoding the very rare triplets AGA/AGG and AGG for arginine. Analysis of genomic fragments from E. coli for both tRNA(arg) genes revealed the presence of defective, cryptic prophages integrated within the impaired tRNA genes. Cloning and supplementation of the limiting tRNA genes argU and argW on helper plasmids improved the translation of the rare AGA and AGG codons. This augmentation improved bacterial growth and enhanced t-PA production in the form of inactive inclusion bodies. This dependence on augmentation of tRNA(arg4) or tRNA(arg5) for improved cell growth and expression was also observed for other genes with a high content of these rare arginine codons. Construction and production of nonglycosylated t-PA in inclusion bodies in E. coli along with improvement of the subsequent renaturation and purification procedures resulted in material comparable to that derived from CHO cells. Deletion of domain-encoding segments yielded various "muteins" of t-PA (e.g., reteplase [rPA]) that could be produced in and activated from the purified inclusion bodies analogously. Furthermore, it was shown that rPA has an extended half-life in the circulation because of its lack of glycosylation and impaired receptor binding capability. rPA was successfully used in various clinical studies. It is a new-generation thrombolytic agent with a longer half-life and can thus be administered more conveniently as a double bolus.
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PMID:The production of improved tissue-type plasminogen activator in Escherichia coli. 1154 55

We recently identified a polymorphic Sp1 binding site in an enhancer at the tissue-type plasminogen activator (tPA) locus (tPA -7,351C/T), which was associated with vascular tPA release. Subjects homozygous for the -7,351C allele had twice the tPA release rate compared to subjects carrying the -7,351T allele. In this study we tested the hypothesis that the tPA -7,351C/T polymorphism is associated with myocardial infarction (MI). In a population-based prospective nested case-control study within northern Sweden, genotypes were determined among 61 MI cases and 120 controls. In a multivariate model, the tPA -7,351C/T polymorphism (OR 2.68 for T allele carriers; 95% CI 1.31-5.50), tPA antigen (OR 1.16; 95% CI 1.07-1.25) and apo A-I (OR, 0.997; 95% CI 0.995-0.999) were independently associated with a first MI. These findings suggest that genetic markers of local tPA release and circulating steady-state tPA levels carry independent prognostic information.
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PMID:Tissue-type plasminogen activator -7,351C/T enhancer polymorphism is associated with a first myocardial infarction. 1184 37

The study was carried out in a group of 285 children and adolescents aged 4-20 yrs. Children were divided according to their main disease: group with obesity, obesity and coexisting hypertension, hypertension and diabetes. Each group was divided into children with positive or negative family history of cardiovascular diseases. We assessed routine lipid parameters, body mass index and new atherosclerosis risk factors: lipoprotein (a), apolipoproteins A-I and B, homocysteine, fibrinogen, t-PA and PAI-1. Positive family history of cardiovascular diseases was found in 28% families, and in 8% families it was premature cardiovascular disease. In 48% children we found hypertension in family. Children with positive family history had significantly higher body mass index (25.4 vs 23.8 kg/m2). In the group with obesity and hypertension we found significantly higher cholesterol (182 vs 160 mg/dl) and LDL-cholesterol level (114 vs 93 mg/dl). Lipoprotein(a) level was significantly higher in children with positive family history (38 vs 28 mg/dl). Significant differencies were also found in apolipoprotein B level (90 vs 84 mg/dl). In logistic regression analysis only BMI and lipoprotein(a) were significant in predicting future cardiovascular events in children. Obese, hypertensive and diabetic children often come from families with cardiovascular diseases. Hypertension is the most often prevalent atherosclerosis risk factor in families. Children with positive family history of cardiovascular diseases have significantly higher body mass index. Out of new atherosclerosis risk factors lipoprotein(a) and apolipoprotein B may have real value in predicting future cardiovascular disease in the child. The aim of the study was to compare obese, hypertensive and diabetic children with positive and negative family history of cardiovascular diseases. In the work we have tried to find which of the new atherosclerosis risk factors may have the real value in predicting future cardiovascular events in children already predisposed to atherosclerosis.
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PMID:[Correlation between body mass index, lipoprotein (a) level and positive family history of cardiovascular diseases in children and adolescents with obesity, hypertension and diabetes]. 1199 45

Ischemic brain and peripheral white blood cells release cytokines, chemokines and other molecules that activate the peripheral white blood cells after stroke. To assess gene expression in these peripheral white blood cells, whole blood was examined using oligonucleotide microarrays in 15 patients at 2.4+/-0.5, 5 and 24 h after onset of ischemic stroke and compared with control blood samples. The 2.4-h blood samples were drawn before patients were treated either with tissue-type plasminogen activator (tPA) alone or with tPA plus Eptifibatide (the Combination approach to Lysis utilizing Eptifibatide And Recombinant tPA trial). Most genes induced in whole blood at 2 to 3 h were also induced at 5 and 24 h. Separate studies showed that the genes induced at 2 to 24 h after stroke were expressed mainly by polymorphonuclear leukocytes and to a lesser degree by monocytes. These genes included: matrix metalloproteinase 9; S100 calcium-binding proteins P, A12 and A9; coagulation factor V; arginase I; carbonic anhydrase IV; lymphocyte antigen 96 (cluster of differentiation (CD)96); monocarboxylic acid transporter (6); ets-2 (erythroblastosis virus E26 oncogene homolog 2); homeobox gene Hox 1.11; cytoskeleton-associated protein 4; N-formylpeptide receptor; ribonuclease-2; N-acetylneuraminate pyruvate lyase; BCL6; glycogen phosphorylase. The fold change of these genes varied from 1.6 to 6.8 and these 18 genes correctly classified 10/15 patients at 2.4 h, 13/15 patients at 5 h and 15/15 patients at 24 h after stroke. These data provide insights into the inflammatory responses after stroke in humans, and should be helpful in diagnosis, understanding etiology and pathogenesis, and guiding acute treatment and development of new treatments for stroke.
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PMID:Gene expression in blood changes rapidly in neutrophils and monocytes after ischemic stroke in humans: a microarray study. 1639 89


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