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)

Long-term H. pylori associated gastritis is recognized as a pathogenic factor in gastric carcinogenesis. In gastric carcinomas the amount and activity of the tissue-type plasminogen activator (t-PA) have been reported to be decreased, whereas those of the urokinase-type plasminogen activator (u-PA) were increased, contributing to the neoplastic and invasive process. The present study was performed to determine t-PA and u-PA levels and activity in gastric mucosa from 102 patients and to investigate whether these levels are influenced by H. pylori infection. The antigen concentration and activity of t-PA and u-PA in corpus mucosa were low (P < 0.001) compared with those in antral mucosa, although for the u-PA activity this did not reach statistical significance. In H. pylori-associated antral gastritis the mucosal t-PA antigen concentration and activity were found to be decreased (P < 0.001) compared with normal mucosa, whereas in H. pylori-associated pangastritis the corpus t-PA levels were not affected. The antigen concentration and activity of u-PA were found to be significantly (P < 0.005) increased, both in H. pylori-associated gastritis of antrum and corpus mucosa. Levels of u-PA in histologically normal corpus mucosa of patients with an H. pylori-associated antral gastritis were also found to be increased (P < 0.05). In conclusion, the alterations in the plasminogen activator profile found in H. pylori-associated gastritis, ie, a decrease in t-PA and an increase in u-PA, show a similar tendency as the previously found alterations in gastric carcinomas, which provides additional support for the possible involvement of H. pylori-associated gastritis in the pathogenesis of gastric carcinoma.
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PMID:Gastric mucosal plasminogen activators in Helicobacter pylori infection. 876 82

The binding of iodine-labelled plasminogen to Helicobacter pylori CCUG 17874 was characterized. Inhibition of the binding was observed after preincubation of H. pylori cells with nonradiolabelled plasminogen, lysine, or the lysine analogue epsilon-aminocaproic acid. Fragments of plasminogen, kringles 1 to 3, kringle 4, and mini-plasminogen, were also studied as potential inhibitors. Mini-plasminogen caused total inhibition of the plasminogen binding, while the other fragments caused only partial inhibition. These findings suggest that H. pylori binds specifically the fifth kringle structure of the plasminogen molecule. Plasminogen binding to H. pylori seems to be independent of culture media and independent of the presence of the cytotoxin-associated CagA antigen. Immunoblot analysis identified two plasminogen binding proteins of 57 and 42 kDa. Scatchard plot analysis revealed one binding mechanism with a Kd value of 7 x 10(-7) M. Conversion of H. pylori cell-bound plasminogen to plasmin in the presence of a tissue-type plasminogen activator was demonstrated by digestion of the chromogenic substrate S-2251. No activation was noted when plasminogen or tissue-type plasminogen activator was incubated with H. pylori cells alone. Formation of H. pylori cell surface-bound plasmin may be important to provide a powerful proteolytic mechanism for gastric tissue penetration in type B gastritis and peptic ulcer disease, since plasmin degrades not only fibrin but also extracellular matrix proteins such as various collagens and fibronectin.
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PMID:Plasminogen binding and activation at the surface of Helicobacter pylori CCUG 17874. 974 6