Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P41181 (collecting duct)
 5,183 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Components of the thioredoxin system were localized in normal rat kidney using immunoperoxidase techniques at the light microscopic level and immunogold techniques at the ultrastructural level. Results from both methods were similar. Thioredoxin, thioredoxin reductases, and peroxiredoxins showed cell-type-specific localization, with the same cell types (proximal and distal tubular epithelial, papillary collecting duct, and transitional epithelial cells) previously identified as having high amounts of antioxidant enzyme immunoreactive proteins and oxidative damage products also having high levels of proteins of the thioredoxin system. In addition, peroxiredoxins II and IV were found in high levels in the cytoplasm of red blood cells, identified in kidney blood vessels. While thioredoxin and thioredoxin reductase 1 were found in all subcellular locations in kidney cells, thioredoxin reductase 2 was found predominantly in mitochondria. Thioredoxin reductase 1 was identified in rat plasma, suggesting it is a secreted protein. Peroxiredoxins often had specific subcellular locations, with peroxiredoxins III and V found in mitochondria and peroxiredoxin IV found in lysosomes. Our results emphasize the complex nature of the thioredoxin system, demonstrating unique cell-type and organelle specificity.
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PMID:Localization of the thioredoxin system in normal rat kidney. 1118 97

Excessive reactive oxygen species play a key role in the pathogenesis of diabetic nephropathy, but to what extent these result from increased generation, impaired antioxidant systems, or both is incompletely understood. Here, we report the expression, localization, and activity of the antioxidant thioredoxin and its endogenous inhibitor thioredoxin interacting protein (TxnIP) in vivo and in vitro. In normal human and rat kidneys, expression of TxnIP mRNA and protein was most abundant in the glomeruli and distal nephron (distal convoluted tubule and collecting ducts). In contrast, thioredoxin mRNA and protein localized to the renal cortex, particularly within the proximal tubules and to a lesser extent in the distal nephron. Induction of diabetes in rats increased expression of TxnIP but not thioredoxin mRNA. Kidneys from patients with diabetic nephropathy had significantly higher levels of TxnIP than control kidneys, but thioredoxin expression did not differ. In vitro, high glucose increased TxnIP expression in mesangial, NRK (proximal tubule), and MDCK (distal tubule/collecting duct) cells, and decreased the expression of thioredoxin in mesangial and MDCK cells. Knockdown of TxnIP with small interference RNA suggested that TxnIP mediates the glucose-induced impairment of thioredoxin activity. Knockdown of TxnIP also abrogated both glucose-induced 3H-proline incorporation (a marker of collagen production) and oxidative stress. Taken together, these findings suggest that impaired thiol reductive capacity contributes to the generation of reactive oxygen species in diabetes in a site- and cell-specific manner.
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PMID:Expression, localization, and function of the thioredoxin system in diabetic nephropathy. 1921 14