Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.73 (urokinase-type plasminogen activator)
 10,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rat adrenal glands were stained immunocytochemically using antibodies against plasminogen activators of the tissue-type (t-PA) and urokinase-type (u-PA). A subpopulation of the cells in the adrenal medulla showed intense cytoplasmic t-PA immunoreactivity, while no u-PA immunoreactivity was detected in any adrenal cells. Fluorescence microscopy of adjacent sections demonstrated that the cells stained for t-PA contained noradrenaline. Analysis with a histochemical fibrin slide technique demonstrated a plasminogen-dependent fibrinolysis in the adrenal medulla. SDS-PAGE of adrenal gland extracts followed by zymography established the molecular weight of this plasminogen activator to be similar to that of rat t-PA. In addition SDS-PAGE followed by immunoblotting with anti-t-PA IgG of adrenal gland extracts revealed one band with an electrophoretic mobility indistinguishable from that found in the zymography. When tissue-sections and immunoblots were incubated with antibodies absorbed with highly purified t-PA no staining was found. In view of the previous finding of t-PA in growth hormone-containing cells of the pituitary gland, these findings substantiate that t-PA can be found in the intact normal organism outside endothelial cells, and further point to t-PA having a function in endocrine cells.
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PMID:Tissue-type plasminogen activator in rat adrenal medulla. 309 16

Although conventional biotechnology used for the synthesis of antibiotics, vitamins, amino acids, nucleotides, enzyme inhibitors and immunomodulating compounds has still a major impact in the production of pharmaceutical compounds, the importance of the new biotechnology is increasing. Whereas in conventional biotechnology naturally occurring strains are screened for production of pharmacologically active compounds, in new biotechnology known organisms are programmed by genetic engineering to produce a distinct protein or glycoprotein of human origin for substitution therapy. Such complex compounds from new biotechnology can be divided into products which might replace compounds which are already on the market by safer recombinant products such as human insulin, human growth hormone, urokinase, factor VIII and products which are new on the market such as interferons, lymphokines, tissue plasminogen activator, oligonucleotide probes, monoclonal antibodies and subunit vaccines. However, only a few of these recombinant products have reached the market such as human insulin, interferon alpha, interferon beta, human growth hormone and recombivax HB. In most cases, depending on the difficulties in demonstrating clinical efficacy, the investigated drugs have reached the marketing phase much faster than conventional chemical drugs. Return on investment of biotechnical produced pharmaceutics mainly depends on the issues of whether the product has to compete with chemically synthesized drugs, whether it is totally new but competes with other bioproducts, whether it is exceptional but the proof of clinical efficacy is difficult, or whether it is totally new and clinical studies are promising.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Biobusiness in the pharmaceutical industry. 343 5

We immunocytochemically stained rat pituitary glands using antibodies against plasminogen activators of the tissue type (t-PA) and the urokinase type (u-PA). A large population of endocrine cells in the anterior lobe of the gland displayed intense cytoplasmic immunoreactivity with anti-t-PA. In some areas of the intermediate lobe we found a weak staining, and we observed weakly staining granular structures in the posterior lobe. Controls included absorption of the antibodies with highly purified t-PA. In addition, SDS PAGE followed by immunoblotting of pituitary gland extracts revealed only one band with an electrophoretic mobility similar to that of t-PA when stained with anti-t-PA IgG. No u-PA immunoreactivity was detected in the rat pituitary gland. Sequential staining experiments using antibodies against growth hormone and t-PA demonstrated that the t-PA-immunoreactive cells constitute a large subpopulation of the growth hormone-containing cells. These findings represent the first direct evidence for the presence of t-PA in cell types other than endothelial cells in the intact normal organism. In this article we discuss the implications of the results for a possible role of t-PA in the posttranslational processing of prohormones.
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PMID:Immunocytochemical demonstration of tissue-type plasminogen activator in endocrine cells of the rat pituitary gland. 389 62

Parenteral nutrition is an expensive therapy that is often necessary in certain situations, such as short-bowel syndrome. In many other conditions, its efficacy remains controversial. Providing optimal parenteral nutrition can be particularly challenging in premature infants while managing metabolic and catheter complications. Use of special nutrients, glutamine, and growth hormone may have benefits in the nutritional management of premature infants and trauma patients. Metabolic complications of parenteral nutrition such as cholestasis might be reduced by early enteral feedings, ursodeoxycholic acid, and cholecystokinin-octapeptide. Trace-element deficiencies may still occur, and thus patients must be monitored carefully. Methods that have been used to prevent or reduce catheter occlusion or infection include heparin, oral anticoagulants, antibiotics, and thrombolytic agents such as urokinase and tissue plasminogen activator.
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PMID:Advances in parenteral nutrition. 894 28

Transgenic mice expressing human urokinase, as well as animals expressing human urokinase receptor under the control of the murine mammary tumor virus (MMTV) long terminal repeat, were established. In the vast majority of the founder animals and their descendants, the transgene was completely methylated, corresponding to down-regulation of transgene expression in the mammary gland. Two lineages with human urokinase receptor as the transgene with mixed methylation of the transgenes were analyzed in more detail. We show here for the first time that the methylation status of the transgene is identical in different organs of an animal, but may differ from animal to animal among the descendents. In the mammary gland, complete methylation of the transgene was incompatible with expression; unmethylated and mixed methylation transgenes gave rise to expression at the RNA as well as at the protein level. The methylation observed was not the consequence of an imprinting process. Surprisingly, in organs other than the mammary gland, such as liver, kidney and spleen, weak expression of the transgene was noted independent of the methylation status of the MMTV promoter. With respect to the molecular mechanism it is unresolved whether the human growth hormone sequence of the transgene harbors a methylation inducing element responsible for the observed methylation pattern.
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PMID:Epigenetic modification of transgenes under the control of the mouse mammary tumor virus LTR: tissue-dependent influence on transcription of the transgenes. 896 Mar 72

Thrombolytic drugs reduce mortality from myocardial infarction and research is focused on newer drugs with improved clinical efficacy. The ideal thrombolytic drug should be effective in dissolving fresh and older thrombi, be rapid in its action with complete dissolution of the thrombus, be able to be given as a bolus and be safe without hypotensive or allergic or immunogenic reactions. The types of agents being developed fall into five broad categories: * mutants or variants of single chain urokinase type plasminogen activator; * mutants or variants of tissue type plasminogen activator; * recombinant chimaeric plasminogen activators; * conjugates of plasminogen activators and anti-fibrin monoclonal antibodies; * compounds derived from haemophagous animals. Within the mutant and variant groups there may be single point mutations which increase the half life or deletion of various amino acid sequences to increase resistance to plasma protease inhibitors or cause more selective binding to fibrin. The recombinant chimaeric plasminogen activators are designer drugs where the kringle regions, the growth hormone domain region, the finger domain region and the serine protease part of the molecules are all cleaved and recombined in various ways to improve potency. The conjugates of plasminogen activators and anti-fibrin and monoclonal antibodies improve the targeting of the agent to fibrin clot. Monoclonal antibodies are commonly used against the seven aminoterminal residues of the beta chain of fibrin. These are cross linked and bound to plasminogen activators. A variety of substances from haemophageous animals are currently being studied including salivary plasminogen activator from vampire bats, venom from southern copperhead snakes and staphylokinase from bacteria. Currently available thrombolytic agents have many limitations, but the novel thrombolytic agents have yet to be tested in clinical trials. With few exceptions, they all act via the plasminogen system and it may be in the future that combinations of anti-platelet and thrombolytic agents may prove to be more efficacious than thrombolytics and aspirin alone.
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PMID:New thrombolytic drugs. 1086 16

Mammalian bladder epithelium functions as an effective permeability barrier. We demonstrate here that this epithelium can also function as a secretory tissue directly involved in modifying urinary protein composition. Our data indicate that normal bovine urothelium synthesizes, as its major differentiation products, two well-known proteases: tissue-type plasminogen activator and urokinase, as well as a serine protease inhibitor, PP5. Moreover, we demonstrate that the urothelium secretes these proteins in a polarized fashion into the urine via a cAMP- and calcium-regulated pathway. Urinary plasminogen activators of ruminants are therefore urothelium derived rather then kidney derived as in some other species; this heterogeneity may have evolved in response to different physiological or dietary factors. In conjunction with our recent finding that transgenic mouse urothelium can secrete ectopically expressed human growth hormone into the urine, our data establish that normal mammalian urothelium can function not only as a permeability barrier but also as a secretor of urinary proteins that can play physiological or pathological roles in the urinary tract.
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PMID:Urothelial function reconsidered: a role in urinary protein secretion. 1113 52

A Continuous Flow Electrophoresis System (CFES) was used on Space Shuttle flight STS-8 to separate specific secretory cells from suspensions of cultured primary human embryonic kidney cells and rat pituitary cells. The objectives were to isolate the subfractions of kidney cells that produce the largest amounts of urokinase (plasminogen activator), and to isolate the subfractions of rat pituitary cells that secrete growth hormone, prolactin, and other hormones. Kidney cells were separated into more than 32 fractions in each of two electrophoretic runs. Electrophoretic mobility distributions in flight experiments were spread more than the ground controls. Multiple assay methods confirmed that all cultured kidney cell fractions produced some urokinase, and five to six fractions produced significantly more urokinase than the other fractions. Several fractions also produced tissue plasminogen activator. The pituitary cells were separated into 48 fractions in each of the two electrophoretic runs, and the amounts of growth hormone (GH) and prolactin (PRL) released into the medium for each cell fraction were determined. Cell fractions were grouped into eight mobility classes and immunocytochemically assayed for the presence of GH, PRL, ACTH, LH, TSH, and FSH. The patterns of hormone distribution indicate that the specialized cells producing GH and PRL are isolatable due to the differences in electrophoretic mobilities.
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PMID:Electrophoretic separation of kidney and pituitary cells on STS-8. 1154 4

We immobilized urokinase (UK) by covalent attachment to activated Sepharose 6B-CL through multi-point amine coupling and evaluated its performance in cleaving a fusion protein, which consisted of recombinant human growth hormone (hGH) and a fragment of glutathione S-transferase that was linked by a tetrapeptide of a UK-specific recognition sequence. Packing densities of aldehyde groups on the activated agarose surface could be controlled in a gel range of 7-60 micromol/ml aldehyde by the amount of glycidol used. The immobilization yield was nearly 100% at pH 10.5, and the specific activity of the immobilized UK was equivalent to about 80% of soluble UK under the assay conditions. The immobilized UK showed an improvement in pH and thermal stability, probably due to the structural rigidity imparted by multi-point linkages to the matrix. The cleavage rate by the immobilized UK was lower than that of the soluble enzyme but the side reaction of cryptic cleavage was significantly decreased, which might suggest that the enzyme's specificity was altered by the immobilization. Cleavage yield in the column packed with immobilized UK was dependent on the feed rate, and the yield was approx. 80% of that of the soluble UK. The monomeric hGH could be obtained by selectively precipitating the uncleaved fusion protein and the GST fragments at an acidic pH.
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PMID:Enzymic cleavage of fusion protein using immobilized urokinase covalently conjugated to glyoxyl-agarose. 1263 Sep 3

The binding of urokinase plasminogen activator (uPA) to its receptor (uPAR) initiates a proteolytic cascade facilitating the activation of matrix metalloproteinase-9 (MMP-9), which in turn degrades the extracellular matrix. These processes have an established role in tumor invasion and metastasis. Our previous work revealed an inverse association between glioma invasion and the expression of uPAR and MMP-9. In the present study, we used the adenovirus serotype 5 vector system to generate a replication-deficient recombinant adenovirus capable of simultaneously expressing antisense uPAR and antisense MMP-9 (Ad-uPAR-MMP-9). This adenoviral construct is driven by the independent promoter elements cytomegalovirus and bovine growth hormone and SV40 polyadenylation signals to down-regulate key steps in the proteolytic cascade. Ad-uPAR-MMP-9 infection of SNB19 cells significantly decreased uPAR and MMP-9 expression as determined by immunohistochemical and Western blotting analyses. A Matrigel invasion assay revealed marked reduction in the invasiveness of the Ad-uPAR-MMP-9-infected cells compared with parental and vector controls. Tumor spheroids infected with Ad-uPAR-MMP-9 and cocultured with fetal rat brain aggregates did not invade rat brain aggregates, whereas 90-95% of the mock and empty vector-infected cells invaded the rat brain aggregates. Intracranial injection of SNB19 cells infected ex vivo with the Ad-uPAR-MMP-9 antisense bicistronic construct showed decreased invasiveness and tumorigenicity. s.c. injections of the bicistronic antisense construct into established tumors (U87 MG) caused tumor regression. These results support the therapeutic potential of targeting the individual components of the uPAR-MMP-9 by using a single adenovirus construct for the treatment of gliomas and other cancers.
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PMID:Synergistic down-regulation of urokinase plasminogen activator receptor and matrix metalloproteinase-9 in SNB19 glioblastoma cells efficiently inhibits glioma cell invasion, angiogenesis, and tumor growth. 1275 Feb 66


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