Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: KEGG:D02003 (NBT)
 1,323 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Microcrystals of calcium oxalate cause an activation of the metabolic burst in polymorphonuclear leukocytes, measured as NBT reduction. Crystal-induced NBT reduction, which was mainly due to superoxide release, was accompanied by enzyme release. Modulation of calcium oxalate-induced activation by several agents resembles the effect of these agents on activation by opsonized zymosan and by phorbol myristate acetate. Both the activation of the metabolic burst and concomitant enzyme release could be counteracted by certain anions, such as oxalate, pyruvate and citrate, indicating that positive charges on the crystals play an important role in crystal-cell interaction. Removal of the negatively charged sialic acid from the cell surface by neuraminidase did not affect the the action of the crystals. The mechanism, by which calcium oxalate activates polymorphonuclear leukocytes, is discussed.
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PMID:Mode of activation of the metabolic burst in polymorphonuclear leukocytes by calcium oxalate crystals. 344 22

Renal cell injury and fixed particle formation is one of the theories of urinary stone formation. The exposure of renal epithelial cells to oxalate ions and calcium oxalate monohydrate crystals can cause free radical generation and increase lipid peroxidation. Tamm-Horsfall protein (THP) has a protective effect on the production of free radicals in vitro. We aimed to show that THP (and its deglycosylated products, D-THP) could protect culture cells from free radical injury in vivo as well as the possible mechanism by which this is done. Exposure of Madin-Darby canine kidney (MDCK) cells to Ox resulted in a significant increase in the release LDH, NBT and MDA, as well as an increase in caspase 3 activity, all of which were further elevated when COM crystals were added. With the addition of THP at 500 nM, there was a significant decrease in the release of LDH and the production of MDA and NBT. A decrease in capase 3 activity was observed when 500 nM THP was added to the culture medium that reached 32.7% and 40.4% of inhibition in CaOx+THP and CaOx+COM+THP, respectively. THP decreased the adhesion of COM crystals to the MDCK cells but lost its effect when THP was deglycosylated. The results indicate that both Ox and COM crystals cause the release of LDH, MDA, NBT and increase the activity of capase 3 in MDCK cells. As a free radical scavenger, THP reduces the amount of free radicals and provides significant protection at a critical concentration of 500 nM. The deglycosylated THP decreased the effect of the protection of the MDCK cells from oxalate-induced injury and an increase of adhesion of the COM crystals to the MDCK cells. Therefore, the effects of THP on the protection of oxalate induced radical injury may be partly due to its intact glycosylation and its adhesion to the cell membrane.
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PMID:Effects of Tamm-Horsfall protein on the protection of MCDK cells from oxalate induced free radical injury. 1262 57