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

To determine the effects of interferon (IFN) treatment for chronic hepatitis C on vascular endothelium, we measured the concentrations of tissue plasminogen activator (t-PA) and its inhibitor (PAI-1) in the plasma from patients before and after IFN treatment for 14 consecutive days. The plasma t-PA and PAI-1 levels were measured before and after treatment. The plasma t-PA level was significantly increased after IFN treatment (p < 0.01) but no significant difference in plasma PAI-1 level was observed before and after treatment. The ratio of t-PA/PAI-1 was significantly increased after IFN treatment (p < 0.05). These changes may be caused by the effect of IFN on endothelium, leading to an activation of the endothelium derived fibrinolysis factors. Increase in plasma t-PA concentration may induce hyperfibrinolysis which may be one of the causes of suborbital hemorrhage. Further study on the fibrinolysis pathway in the blood is necessary to elucidate the mechanisms of the many side effects observed during IFN treatment.
 ...
PMID:[Changes in plasma tissue plasminogen activator (t-PA) and plasminogen activator inhibitor 1 (PAI-1) by the interferon treatment for chronic hepatitis C]. 747 59

Platelet-derived growth factor (PDGF)-induced smooth muscle cell (SMC) fibrinolysis is necessary for SMC migration. In order to determine whether the T-cell lymphokines interleukin-4 (IL-4) and gamma interferon (gamma-IFN) affect SMC fibrinolysis and migration, we examined the effects of human recombinant IL-4 and gamma-IFN on human aortic SMC tissue-type plasminogen activator (TPA), urokinase-type plasminogen activator (UPA), and plasminogen activator inhibitor type-1 (PAI-1) antigen production, as determined by enzyme-linked immunosorbent assays. Although IL-4 had no direct effect on SMC TPA antigen, IL-4 potentiated SMC TPA antigen levels and activity in conditioned media and cellular lysates in media containing 2% fetal bovine serum but did not change UPA or PAI-1 production. gamma-IFN attenuated IL-4 augmentation of SMC TPA antigen production in conditioned media, although gamma-IFN itself had no direct effects on SMC TPA and PAI-1 antigen production. IL-4 augmented PDGF induction of SMC TPA antigen. gamma-IFN inhibited PDGF induction of SMC TPA antigen and IL-4 potentiation of this process. gamma-IFN diminished the promigratory effects of both IL-4 and PDGF on in vitro SMC migration. Tranexamic acid, a plasmin inhibitor, abrogated the stimulation of SMC migration by IL-4. Therefore, IL-4 and gamma-IFN modulate the induction of SMC TPA and SMC migration by 2% fetal bovine serum and PDGF.
 ...
PMID:T-cell lymphokines, interleukin-4 and gamma interferon, modulate the induction of vascular smooth muscle cell tissue plasminogen activator and migration by serum and platelet-derived growth factor. 758 21

Two fibroblast cell lines (PG3KT and PG1NA) derived from Hutchinson-Gilford syndrome (progeria) cases were characterized, at various population doubling levels (PDL), with respect to the capacity of ultraviolet light (UV, mainly 254 nm wavelength)-induced unscheduled DNA synthesis (UDS) and plasminogen activator-like protease activity (PA). The UDS levels in PG3KT and PG1NA cells at PDL 2-3 were only slightly less than those in normal fibroblasts. With increasing PDL, both progeria cell lines exhibited reduction of the UDS levels and undetectable ones at PDL 9-11. Prompt and transient induction of PA was also detectable at less than PDL 5, whereas it was undectable at higher PDL. However, the levels of UDS and PA induction were increased about 3-7 times after pretreatment with 100 IU/ml human interferon (HuIFN)-beta preparations for more than 24 h prior to UV irradiation, although UDS and PA were undetectable at more than PDL 10. These results suggest that cytokines such as HuIFN-beta transiently compensate for the decreases in UDS and PA inducibility in progeria cells with aging.
 ...
PMID:Reduction of unscheduled DNA synthesis and plasminogen activator activity in Hutchinson-Gilford fibroblasts during passaging in vitro: partial correction by interferon-beta. 786 76

Interferons are known to prevent liver collagen by an antifibrogenic mechanism that involves mRNA procollagen regulation. The aim of the present work was to determine whether interferon could also decrease collagen by increasing its degradation. Fibrosis was induced in male Wistar rats by double ligation and section of the common bile duct. Interferon-alpha 2b (100,000 IU/rat s.c.) was administered to bile duct ligated rats daily after surgery for 4 weeks. Interferon increased the capacity of the liver to degrade type I and III collagens and matrigel. In addition, the plasminogen activator activity also increased. Since plasminogens are thought to be key participants in the balance of proteolytic activities that regulate extracellular matrix degradation, their elevation may also provide another antifibrotic (proteolytic) mechanism of action of interferon.
 ...
PMID:Interferon-alpha 2b increases fibrolysis in fibrotic livers from bile duct ligated rats: possible participation of the plasminogen activator. 896 90

Liver endothelial cells are important components of the tissue along the hepatic sinusoid. They are responsible for microcirculation in the liver and scavenger functions. It would therefore be important to include these cells in any hybrid type of artificial liver in addition to hepatocytes. However, it is difficult to culture these cells in vitro. The development of a liver endothelial cell line, which maintains the characteristics of the primary culture, would thus be of great benefit in the development of an artificial liver. In the present study we established immortalized liver endothelial cells from the liver of an H-2Kb-tsA58 transgenic mouse, which harbors the SV40 TAg gene. Hepatic sinusoidal cells isolated from H-2Kb-tsA58 mouse proliferated in the presence of gamma-interferon at 33 degrees C. Four clones were established, out of which clone M1 had the highest amounts of PGI2 production, as well as plasminogen activator activity and internalized acetylated low density lipoprotein. On culture dishes the M1 cells grew individually and spread. Sieve plates on the cell surface were not readily visible, but small pores were detected under electron microscopic observation. These results suggest that M1 clone cells originated from liver endothelial cells. Moreover it was possible to culture the immortalized liver endothelial cells in a radial-flow bioreactor for 5 days, with a maximum 6-keto prostaglandin F1alpha production of 25 microg per day. This suggests that immortalized liver endothelial cells and a radial-flow bioreactor can prove useful tools in the development an artificial liver.
 ...
PMID:High density culture of immortalized liver endothelial cells in the radial-flow bioreactor in the development of an artificial liver. 964 65

Recombinant human gamma interferon was used to treat 10 atopic dermatitis patients. Recombinant gamma interferon was administered weekly for three consecutive days at 50 microg/M2 SQ for four weeks. All patients' dermatitis improved with recombinant gamma interferon therapy and plasma tumor necrosis factor-alpha levels rose with treatment. Recombinant gamma interferon treatment positively correlated with reduced total plasma fibrinolysis as measured by the fibrin lysis plate, plasmin-alpha2antiplasmin complexes, and tissue type plasminogen activator levels. Accordingly, plasminogen activator inhibitor levels increased. Treatment also was associated with a transient increase in thrombin-antithrombin III complexes. Recombinant gamma interferon resulted in a significant increase in C1 inhibitor antigen but not activity. Plasma prekallikrein, high molecular weight kininogen, and factor XII levels were not decreased. However, 5 of the 10 atopic dermatitis patients before therapy had circulating cleaved plasma high molecular weight kininogen detected on immunoblot, indicating prior kallikrein formation. The cleaved, circulating plasma high molecular weight kininogen disappeared in four out of the five original patients who were reexamined at one year after treatment. These combined data indicated that recombinant gamma interferon treatment reduced total plasma fibrinolysis. In untreated atopic dermatitis, circulating cleaved high molecular weight kininogen also may be a presenting manifestation.
 ...
PMID:Gamma interferon administration to patients with atopic dermatitis inhibits fibrinolysis and elevates C1 inhibitor. 966 47

Process development for biopharmaceuticals is dictated by product quality, drug safety and economy of the manufacturing process. Not surprisingly, these factors also play a key role in the evaluation of mammalian cell expression systems to be used in the production of pharmacologically active glycoproteins. To date, the most prominent candidates for efficient expression of glycoproteins are mammalian cell lines such as mouse fibroblast cells (C 127-BPV), Chinese hamster ovary cells (CHO-DHFR, CHO-NEOSPLA, CHO-GS), mouse myeloma cells (NSO-GS) as well as transgenic animals carrying c-DNA or genomic DNA which codes for the protein of interest. The expression titer in the case of glycoproteins is mainly determined by the promoter construct, the site of integration into the chromosome, the copy number and the type of protein in question. Based on expression titer, CHO-NEOSPLA and NSO-GS expression systems are most effective in the production of monoclonal antibodies and, to a lesser extent, of recombinant DNA derived proteins. However, based on overall product yield, expression of recombinant DNA derived proteins in transgenic animals is by far the most promising system. Therefore, for proteins required in large quantities, transgenic expression systems offer an attractive choice. However, cost of goods for products for which the dosage or the overall annual quantities are low, is dominated by downstream processing, filling, lyophilization and packaging and not by the fermentation process. Such proteins are preferentially produced by classical mammalian cell culture systems. Concerns which have to be addressed with respect to drug safety in the transgenic animal approach are the size of the herd, genetic stability from animal to animal, variation in productivity and in impurity profiles during lactation periods, microbial, viral, mycoplasma and prion contaminants, the dependence on health status and the life span of the animal. In a number of cases glycosylation of the protein is relevant for the prevention of immunogenicity of the protein, the pharmacological activity, the pharmacokinetic profile, solubility and stability against proteolysis. The glycosylation pattern, depending on protein structure, is influenced by the enzymatic system of the host cell as well as by fermentation conditions. Therefore, selection of host cells and culture conditions must take into account the requirement for a specific and stable glycosylation pattern. For the assessment of glycovariants, a number of protein analytical methods such as peptide mapping, isoelectric focusing, oligosaccharide mapping, MALDI-TOF (matrix assisted laser desorption mass spectrometry-time of flight), capillary electrophoresis and specific potency assays are available. In our experiments, glycosylation of proteins expressed in CHO cells was demonstrated to be very stable. Only extreme process times, cultivation methods and ammonium ion concentrations had an influence on the glycosylation profile. Among the three products investigated--tissue plasminogen activator (t-PA), interferon omega and soluble intercellular adhesion molecule (s-ICAM)--t-PA expressed the most stable glycosylation pattern. Only at extreme ammonium concentrations an increase of mannose-5 structures was observed, whereas biantennary complex structures were reduced. On the other hand, interferon omega and s-ICAM showed greater susceptibility to increased ammonium concentrations and to adherent cultivation. Such conditions induced quantitative changes to the glycosylation pattern favoring the appearance of higher branched structures. Short cultivation times resulted in more heterogenous oligosaccharide structures. Since the glycosylation of the three proteins is different in the same host cell, the amino acid sequence of the protein apparently influences the glycosylation pattern and its sensitivity to culture conditions. In NSO-mouse myeloma cells, production of s-ICAM is two times as high as in CHO cells
 ...
PMID:Appropriate mammalian expression systems for biopharmaceuticals. 974 18

Betaseron, an analogue of human beta-interferon where serine was genetically engineered to substitute for cysteine at position 17, is produced in E. coli. The molecule is a small polypeptide of 165 amino acids with a single disulphide bond, and is non-glycosylated. The site-specific substitution was made to obtain a product that is more stable upon storage. Similar to native IFN-beta, Betaseron is hydrophobic in nature and has been shown to have the same panel of biological activities which includes antiviral activity against a variety of viruses, inhibition of cell growth, activation of natural killer cells, and binding to interferon receptors on the cell surface. Betaseron has been tested in a wide variety of clinical settings since 1983. The pivotal trial for the treatment of relapsing-remitting multiple sclerosis began in 1988. A PLA was filed for this indication in 1992 by Berlex and Chiron, and FDA approval was received in 1993. Betaseron is synthesized in E. coli and deposited as inclusion bodies. The manufacturing process involves solubilization and reduction of the insoluble protein, followed by purification by organic extraction, cystine oxidation and size exclusion chromatographic steps. The purified Betaseron is formulated with human serum albumin to maintain solubility at neutral pH. The complete primary sequence of Betaseron was verified by amino and carboxy-terminal sequence analysis, peptide mapping, amino acid analysis and fragment analysis after chemical cleavages. Overlapping amino acid sequence information confirmed that the amino acid sequence is the same as predicted by the DNA sequence. The amino-terminal methionine of Betaseron is removed after synthesis in E. coli. An intramolecular disulphide bond between Cys 31 and Cys 141 formed during the manufacturing process is routinely confirmed by peptide map analysis. The purity of Betaseron is assessed using a panel of analytical methods including non-reducing and reducing SDS-PAGE and reversed phase HPLC analysis where minor product-related components can be identified. These minor species were characterized with respect to their biological and biochemical properties, and identified using a variety of approaches including construction of additional, beta-interferon analogs. There is significant redundancy in the release testing of Betaseron. The amount of characterization information available on this relatively simple molecule along with the extensive manufacturing experience would suggest that some redundant testing could be eliminated for this well-characterized protein.
 ...
PMID:Betaseron. 989 May 22

Interleukin (IL-)1 stimulates prostaglandin E(2)(PGE(2)) generation in fibroblasts, and preferential couplings between particular phospholipase A(2)(PLA(2)) and cyclooxygenase (COX) isozymes are implicated with IL-1-induced delayed PGE(2)generation. The regulatory effects of interferon (IFN)-gamma and IL-4 on IL-1beta-induced COX, PLA(2)isoforms expression and terminal delayed PGE(2)generation were examined in three types of human fibroblasts. These human fibroblasts constitutively expressed cytosolic PLA(2)(cPLA(2)) and COX-1 enzymes, and exhibited delayed PGE(2)generation in response to IL-1beta. IL-1beta also stimulated expression of cPLA(2)and COX-2 only, while constitutive and IL-1beta-induced type IIA and type V secretory PLA(2)s (sPLA(2)s) expression could not be detected. A COX-2 inhibitor and cPLA(2)inhibitor markedly suppressed the IL-1beta-induced delayed PGE(2)generation, while a type IIA sPLA(2)inhibitor failed to affect it. IFN-gamma and IL-4 dramatically inhibited the IL-1beta-induced delayed PGE(2)generation; these cytokines apparently suppressed IL-1beta-stimulated COX-2 expression and only weakly suppressed cPLA(2)expression in response to IL-1beta. These results indicate that IL-1beta-induced delayed PGE(2)generation in these human fibroblasts mainly depends on de novo induction of COX-2 and cPLA(2), irrespective of the constitutive presence of COX-1, and that IFN-gamma and IL-4 inhibit IL-1beta-induced delayed PGE(2)generation by suppressing, predominantly, COX-2 expression.
 ...
PMID:Interferon-gamma and interleukin 4 inhibit interleukin 1beta-induced delayed prostaglandin E(2)generation through suppression of cyclooxygenase-2 expression in human fibroblasts. 1084 35

Antiluteolytic actions of bovine interferon-tau (bIFN-tau) require suppression of prostaglandin F(2 alpha) (PGF(2 alpha)) production. Our objective was to test whether bIFN-tau could block PGF(2 alpha) production and synthesis of phospholipase A(2) (PLA(2)) and cyclooxygenase-2 (COX-2) enzymes induced by a protein kinase C (PKC) stimulator (phorbol 12,13 dibutyrate; PDBu). Bovine endometrial epithelial (BEND) cells were treated with PDBu in the presence or absence of bIFN-tau. Medium samples were analyzed for concentrations of PGF(2 alpha), whole-cell extracts were analyzed for abundance of PLA(2) and COX-2 by immunoblotting, and RNA extracts were examined for steady-state levels of COX-2 mRNA by Northern blotting. The PDBu stimulated production of PGF(2 alpha) between 3 and 12 h, levels of COX-2 mRNA by 3 h and protein expression of COX-2 and PLA(2) by 6 and 12 h, respectively. Added concomitantly with PDBu, bIFN-tau suppressed PGF(2 alpha) production, steady-state levels of COX-2 mRNA, and expression of COX-2 and PLA(2) proteins. Added after a 3-h stimulation with PDBu alone, bIFN-tau suppressed PGF(2 alpha) production after 1 h. Bovine IFN-tau inhibited intracellular mechanisms responsible for PGF(2 alpha) production in BEND cells, and this could be through both cytosolic and nuclear actions.
 ...
PMID:Interferon-tau modulates phorbol ester-induced production of prostaglandin and expression of cyclooxygenase-2 and phospholipase-A(2) from bovine endometrial cells. 1090 45


<< Previous 1 2 3 4 5 Next >>