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)

Immunohistochemistry is an important tool that is often used for the diagnosis of several diseases in the pathology laboratory. The quality and sensitivity of immunohistochemical staining is affected by formalin fixation, which results in variable loss of antigenicity, known as a masking effect. While the sensitivity of immunohistochemistry is excellent for certain antigens, other antigens such as COX-1 and COX-2 are difficult to identify, especially in formalin-fixed, paraffin sections. Antigen retrieval is a technique that re-exposes epitopes and allows detection of masked antigens with standard immunohistochemical procedures. One common method involves partial, enzymatic pre-digestion with trypsin or pepsin while other, nonenzymatic procedures or heat-mediated antigen retrieval methods include pressure-cookers, hot plates, or microwave (MW) irradiation of tissue sections in water or a variety of antigen-retrieval solutions. In this chapter, we will describe a technique that provides a more reliable, much simpler approach for the demonstration of cyclooxygenase-1 and cyclooxygenase-2 expression in frozen, vibratome or paraffin sections, and/or cells in cultures.
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PMID:Immunohistochemical staining of cyclooxygenases with monoclonal antibodies. 1908 50

Proteinase-activated receptor (PAR)(2) is activated by trypsin-like serine proteinases and has been implicated in intestinal inflammation. However, its role in the regulation of intestinal mucosal function remains unclear. Using the intestinal epithelial cell line, SCBN, we have studied the stimulus-secretion coupling mechanisms of PAR(2)-induced epithelial chloride transport, focusing on cyclooxygenase (COX)-1 and COX-2 activities and prostaglandin (PG) E(2) secretion. SCBN monolayers were grown on Snapwell supports, mounted in modified Ussing chambers, and exposed to the activating peptide, SLIGRL-NH(2) (50 microM), to activate PAR(2). Pretreatment with inhibitors of cytosolic PLA(2) (cPLA(2)) (AACOCF3, arachidonyltrifluoromethyl ketone), COX-1 [SC560, 5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-(trifluoromethyl)-1H-pyrazole], and COX-2 (celecoxib) resulted in a significant concentration-dependent attenuation of PAR(2)-induced changes in short-circuit current. Immunoblot analysis showed a PAR(2)-induced increase in cPLA(2) phosphorylation that was blocked by the mitogen-activated protein kinase kinase inhibitor, PD98059 [2-(2-amino-3methoxyphenyl)-4H-1benzopyran-4-one, C(16)H(13)NO(3)], and the pan-protein kinase C inhibitor, GFX (bisindolylmaleimide). PAR(2) stimulation also resulted in a large increase in the production of PGE(2) as determined by enzyme-linked immunosorbent assay and was also blocked by PD98059 and GFX. Immunofluorescence and immunoblot analysis determined that EP2 and EP4 are expressed at the basolateral membrane of SCBN cells. Through the use of selective inhibitors (EP2, AH6809 [6-isopropoxy-9-oxoxanthene-2-carboxylic acid]; EP4, GW627368X [N-[2[4,9-diethoxy-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl)phenyl] acetyl]benzene sulphonamide]), it was found that both EP2 and EP4 were involved in mediating the PAR(2)-induced chloride secretory response. We conclude that basolateral PAR(2) activation induces epithelial chloride secretion that is mediated by cPLA(2), COX-1, COX-2, and the subsequent release of PGE(2). The production of PGE(2) results in an autocrine secretory response that is dependent on basolateral EP2 and EP4 receptors.
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PMID:Prostaglandin E2 derived from cyclooxygenases 1 and 2 mediates intestinal epithelial ion transport stimulated by the activation of protease-activated receptor 2. 1919 Feb 38

A novel series of nitrogen-containing chalcones were synthesized by Mannich reaction and were screened for anti-inflammatory related activities such as inhibition of cyclooxygenase-2 (COX-2), trypsin and beta-glucuronidase. The antioxidant potential was demonstrated using 1,1-diphenyl-2-picryl hydrazine (DPPH) radical scavenging activity. The results of the above studies shows that the compounds synthesized were found to be effective inhibitors of above pro-inflammatory enzymes, and were found to be possess moderate radical scavenging potential. Overall, the results of the studies reveal that the chalcones with N-methyl piperazine methyl and piperidine methyl substitution (4c, 3b, 4d, 6b) seems to be important for inhibition of beta-glucuronidase. Whereas the chalcones with piperidine methyl substitution (8b, 7b, 7c, 6c, 4b, 3c, 3b) were observed as effective inhibitors of COX-2, while the same compounds were found to be less reactive against COX-1 as compared to COX-2.
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PMID:Synthesis and biological evaluation of nitrogen-containing chalcones as possible anti-inflammatory and antioxidant agents. 2000 7


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