Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In 71 patients that underwent intracapsular extraction of the cataract it was possible to collect aqueous humor (a.h.) in sufficient quantities at the beginning and at the end of the operation. Using radial immunodiffusion albumin, IgG and alpha-1-antitrypsin were measured in the samples. In secondary a.h. huge variations in the concentrations were apparent. The primary permeability of the blood-aqueous barrier and the time between sampling had no influence on the relative increase of the proteins. No statistically significant difference was found between normotensives and hypertensives and patients with or without myopia of higher degree (over 6 diopters). The relative increase of proteins according to their difference in molecular weight followed the same pattern as described for anterior uveitis. In patients for whom an enzymatic zonulolysis with trypsin was used for the extraction, the relative increase of IgG was significantly smaller than in those that did not receive this treatment (P less than 0.005). The possible sources contributing to the formation of secondary a.h. are discussed.
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PMID:Immediate changes in protein-concentration in aqueous humor induced by intracapsular lens extraction in human eyes. 11 24

By using two specific receptor assays, we identified and partially characterized receptors for transforming growth factor-beta 1 (TGF-beta 1) on porcine trabecular cells in vitro. Cultured trabecular cells were incubated with labeled TGF-beta 1 and analyzed by flow cytometry. Pretreatment with trypsin or preincubation with cold TGF-beta 1 or a neutralizing antibody to TGF-beta 1 inhibited the binding of labeled TGF-beta 1. 125I-TGF-beta 1 was cross-linked covalently to cell surface receptors on the trabecular cells. By SDS-PAGE and autoradiography, we identified three labeled macromolecular species of receptors, two of which had apparent molecular weights greater than 212 kDa and one of which had an apparent molecular weight of approximately 80-90 kDa under reducing conditions. The low and high molecular weight species probably represent type II and type III TGF-beta 1 receptors, respectively. At concentrations of 0.5 and 1 ng/ml, activated TGF-beta 1 caused retraction and a marked decrease in the rate of proliferation and in the motility of trabecular cells in vitro. Our findings implicate TGF-beta 1 in the modulation of the functional homeostasis of trabecular cells and suggest that the aqueous humor contains a level of TGF-beta 1 which, once activated, is sufficient to exert a biologic effect on the trabecular meshwork.
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PMID:Identification and partial characterization of TGF-beta 1 receptors on trabecular cells. 131 71

Activity of tissue and blood plasma kallikreins as well as total content of their inactive precursors were studied in rabbit eye structures and media: iris, ciliary body, cornea, vascular striatum, retina, aqueous humor, tear liquid, lacrimal gland by means of fluorimetric procedure using Z-Phe-Arg-MCA as a substrate. Dissimilar capacity of the trypsin soya bean inhibitor and of aprotinin (basic inhibitor of Kunitz type) to inhibit tissue and blood plasma kallikreins enabled to differentiate the enzymatic activity. Lacrimal gland contained the highest activity of tissue kallikrein which amounted to 70% of total Z-Phe-Arg-MCA-hydrolyzing activity of the homogenate. Total Z-Phe-Arg-MCA-amidase activity and activity of individual kallikreins was distinctly lower in all the eye structures and media studied as compared with that of lacrimal gland. Activity of tissue kallikrein was higher than blood serum kallikrein activity in iris, ciliary body, vascular striatum, retina and conjunctiva. The highest content of prekallikreins was found in conjunctiva, aqueous humor, iris and ciliary body. Tissue and blood plasma kallikrein-kinin systems appear to carry out dissimilar functions in eye tissue structures; they are apparently involved in pathogenesis of some eye diseases.
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PMID:[Activity of tissue and plasma kallikrein and level of their precursors in eye tissue structures and media of healthy rabbits]. 172 76

Anterior uveitis or iritis occurs in a variety of systemic diseases including sarcoid, Behcet's, and spondyloarthritis. Iritis is, therefore, presumed to result from a variety of pathogenetic mechanisms. We hypothesized that unique chemotactic factors should be associated with different etiologies for inflammation. We have tested this hypothesis using rabbit models of anterior uveitis. We have found that aqueous humor generally contained chemotactic activity for monocytes 24 h after an intravitreal injection of endotoxin, killed mycobacteria, or human serum albumin (in a rabbit previously immunized against human serum albumin). Anterior chamber paracentesis resulted in aqueous humor with a high protein content. However, in contrast to the other models of inflammation, paracentesis did not result in a cellular infiltrate in the anterior chamber, and aqueous humor after paracentesis was not chemotactic. For either immunologically mediated inflammation or for inflammation resulting from injection of a killed bacterial product, chemotactic activity could be digested by papain or trypsin and tended to coelute with albumin on either gel filtration or ion-exchange chromatography. These observations suggest that a similar chemotactic factor for monocytes appears to be associated with ocular inflammation that follows either an immune response or injection of a killed bacterial product.
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PMID:Similar chemotactic factor for monocytes predominates in different animal models of uveitis. 341 43

Rabbit skin and Tenon's capsule fibroblasts were cultured in media containing 20% rabbit aqueous humor as a stimulatory agent. Cell stimulation was quantitated by 3H-thymidine uptake. The aqueous humor was either: (1) untreated; (2) heated at 37 degrees C for 60 min; (3) boiled for 2 min; or (4) heated at 37 degrees C for 60 min with 0.025% trypsin, followed by boiling. The effects of the various treatments of aqueous humor on cell stimulation were compared among themselves and to 10% fetal bovine serum. It was found that: (1) heating of aqueous humor at 37 degrees C for up to 60 min had no apparent effect on its ability to stimulate DNA synthesis in culture; (2) boiling and trypsin plus boiling reduced the ability of 20% aqueous humor to promote thymidine uptake to varying degrees; (3) 20% untreated aqueous humor was more effective than 10% fetal bovine serum in stimulating DNA synthesis in Tenon's capsule fibroblasts; skin fibroblasts responded similarly to both media.
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PMID:Heat and protease treatment of aqueous humor: effect on cell DNA synthesis and growth. 397 36

Adenylate cyclase activity was studied on the two epithelial cell types of bovine ciliary process after digestion by trypsin and purification by density gradient centrifugation. cAMP formation after isoproterenol stimulation showed that non pigmented cells were particularly enriched in adenylate cyclase activity. Furthermore pharmacological characteristics of this enzyme indicated that adenylate cyclase-associated beta adrenergic receptors were of beta 2 type in each kind of epithelial cells. These results support the hypothesis that beta adrenergic compounds modulate aqueous humor production through a direct effect on ciliary epithelium and enrichment of beta adrenergic sensitive adenylate cyclase activity in non pigmented epithelial cells suggests that these particular cells may play an important role in aqueous humor secretion.
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PMID:Pharmacological characteristics of beta-adrenergic-sensitive adenylate cyclase in non pigmented and in pigmented cells of bovine ciliary process. 615 85

The ciliary epithelium secretes aqueous humor, an intraocular fluid whose production is regulated in part by transmembrane signaling pathways including those mediated by G protein-coupled receptors. Many drugs, such as beta-adrenergic receptor (AR) antagonists and alpha2-AR agonists, are used to lower intraocular pressure by presumably decreasing fluid transport across this epithelium. Hence, our purpose was to establish a ciliary epithelial organ culture system suitable for the study of cell signaling pathways. A trypsin-mediated dissection method was established to isolate bovine ciliary epithelial sheets. These sheets were cultured in a 5% CO2 incubator. The quality was assessed by light microscopy, by protein analysis, and by the evaluation of epinephrine-mediated phosphoinositide turnover. The cultured epithelial explants were viable as evidenced by minimal trypan blue staining. The explants were composed primarily of nonpigmented cells and some pigmented cells, but no other ciliary body tissues were present on histology. Membrane preparations showed proteins with a distribution from 31 to 116 kDa. Epinephrine caused a dose-dependent increase in [3H]inositol phosphates (InsPs) accumulation with a maximal increase of two- to three-fold over basal levels. This epinephrine-mediated increase was inhibited by prazosin. We established an organ culture system of isolated bovine ciliary epithelium suitable for the study of transmembrane signaling pathways.
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PMID:Cell signaling in bovine ciliary epithelial organ culture. 1067 33

Data obtained with the neutral red cytotoxicity assay reveal that human lens epithelial cells in culture are highly sensitive to low micromolar concentrations of unsaturated, cis-configured fatty acids in the following order: arachidonic acid>linolenic acid=linoleic acid=oleic acid, whereas the saturated fatty acids are much less effective. Though the cytotoxic effects of the unsaturated fatty acids could not be discerned from effects of their oxidation products, the fact that oleic acid is equally cytotoxic as linoleic acid or linolenic acid as well as previously reported findings with bovine lens epithelial cells support the idea that the unsaturated fatty acid molecules directly account for the cytotoxicity and not their products of lipid peroxidation. Bleb formation and cell retraction are early morphological signs of fatty acid-induced lens cell damage. These cellular alterations are accompanied by an aggregation of intermediate filaments in a first step, whereas the disorganization of microfilaments occurs at a later time and only at higher fatty acid concentrations. Measurements of protein-, RNA- and DNA-synthesis turned out to be much less sensitive parameters for the fatty acid-induced damage of lens cells. The uptake rate of linoleic acid by human lens cells is relatively high (4.35 fmol sec(-1) per 1000 cells), 30 and 50% higher as compared with diploid human embryonal lung fibroblasts and chemically transformed mouse fibroblasts, respectively. Saturation kinetics in combination with competition between linoleic acid, oleic acid and palmitic acid on one hand and ineffectiveness of trypsin and DIDS treatment on the other hand hint at cytoplasmic fatty acid binding proteins as receptors with high binding affinity (5.55 micromol l(-1), calculated for the linoleic acid-albumin complex) to be involved in the fatty acid uptake in human lens cells. Cellular fatty acid uptake is mainly influenced by the albumin concentrations present in physiological solutions. Albumin determinations in aqueous humor from 177 cataract patients reveal an age-dependent, statistically significant albumin rise with average values below 2 micromol l(-1) up to the age of 40 years to about 4 micromol l(-1) at the age between 80 and 90 years with single values up to 10 micromol l(-1). Using physiological fatty acid mixtures it is demonstrated that fatty acid-induced lens cell damage is strongly increased by elevated albumin concentrations found in aqueous humor of the elderly, who already have cataracts. Free fatty acid induced lens cell damage as a possible cause for age-dependent cataracts as well as a molecular link between systemic diseases such as diabetes and cataract formation is discussed.
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PMID:Fatty acid cytotoxicity to human lens epithelial cells. 1550 Aug 27

The aim of this study was to investigate the protein content in aqueous humor in eyes with and without pseudoexfoliations (PEX) and to evaluate the quantitative proteomics method, isobaric tagging for relative and absolute protein quantification (iTRAQ), in combination with two separation methods followed by matrix-assisted Laser desorption/ionization (MALDI) mass spectrometry and tandem mass spectrometry (MS/MS). During cataract surgery, samples of aqueous humor were collected from 20 eyes with PEX and from 18 control eyes. The relative concentrations of proteins in the pooled samples of ten PEX eyes and eight controls were evaluated after trypsin digestion and Labeling of the peptides with (iTRAQ) reagent. Two separation methods, Liquid chromatography (LC) and capillary electrophoresis (CE) were used, followed by MALDI mass spectrometry and MS/MS. Furthermore, 1D gel electrophoresis was performed on the remaining ten pooled PEX samples and ten control samples. The gel material was separated by nano-liquid chromatography (nano-LC) followed by Linear-ion-trap quadrupole Fourier transformation ion cyclotron resonance (FT-ICR). Fifty four proteins were identified in the LC runs and 24 with CE. The relative concentrations of beta-crystallines B2 and S were raised and those of angiotensinogen and osteopontin Lowered in the PEX sample compared to the control. The trends regarding beta-crystallines B2, angiotensinogen and osteopontin were confirmed by the 1D gel electrophoresis.
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PMID:Proteins in aqueous humor from cataract patients with and without pseudoexfoliation syndrome. 2365 98