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

The vitamin D-receptor protein and its mRNA were localized in microscope sections of paraffin-embedded mammalian kidneys by means of immunocytochemistry and in situ hybridization, respectively. A monoclonal antibody against chicken intestinal vitamin D receptor immunostained the nucleus and cytoplasm of cells within the distal convoluted tubule, connecting segment, and initial cortical collecting duct of both rats and pigs. Although fainter, immunostaining also was present over proximal tubular cells. (35S)UTP-labeled cRNA probes were detected over both the proximal and distal portions of the mouse nephron, but silver grain densities were 5.8-fold greater over the latter. In conclusion, localization of both the vitamin D-receptor protein and its mRNA in both the proximal and distal nephron of adult mammals suggests that the gene for this protein is expressed in cells at both of these sites. The intensity of immunostaining and the density of cRNA-associated silver grains suggest that vitamin D-receptor gene expression is greatest in the distal nephron.
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PMID:Vitamin D receptor gene expression in mammalian kidney. 787 36

The kidney is not only a primary vitamin D target organ but also is a key site of vitamin D metabolism. Recent studies have shown that vitamin D has important physiologic effects on proliferation and differentiation in a variety of benign and malignant cells. Our preliminary immunohistochemical study showed that vitamin D receptor (VDR) was highly expressed in renal distal tubules and collecting ducts, whereas the renal proximal tubules and glomeruli did not express VDR. These observations led us to study the expression of VDR in various kidney tumors to determine the possible diagnostic utility of VDR. Paraffin tissue microarray (TMA) blocks were constructed containing core cylinders from clear cell (52), papillary (35), chromophobe (20), sarcomatoid (20), and metastatic (59) renal cell carcinomas (RCCs). Oncocytomas (20), normal adult kidneys (12), and normal adult adrenals (6) were also included. In addition, 30 clear cell RCCs and 3 collecting duct carcinomas were also studied using conventional sections. Furthermore, VDR messenger RNA and protein expression was also quantified using real-time reverse transcriptase-polymerase chain reaction and Western blot analysis. Vitamin D receptor was strongly positive in collecting duct carcinomas (100% [3/3], cytoplasmic), papillary RCCs (94% [33/35], cytoplasmic), chromophobe RCCs (85% [17/20], membranous), and oncocytomas (90% [18/20], cytoplasmic with perinuclear accentuation). In contrast, VDR expression was focal/weak and present only in the peripheral regions of clear cell RCCs. Vitamin D receptor was weakly positive in sarcomatoid variant RCCs (88% [14/16]) regardless of the type of associated original RCC. Overall, VDR is a discriminative marker for renal cell tumors. The preferential expression of VDR in chromophobe RCCs, oncocytomas, and collecting duct carcinomas is in agreement with the concept that these tumors differentiate toward epithelium lining the distal convoluted tubules and collecting ducts. Considering the different VDR expression patterns, VDR is a useful ancillary tool in distinguishing chromophobe RCCs from oncocytomas. In addition, the focal and much weaker VDR expression in clear cell RCCs makes VDR valuable in distinguishing clear cell RCC from other types of RCCs.
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PMID:Expression of vitamin D3 receptor in kidney tumors. 1694 27

Many clinical and animal studies suggest that vitamin D and its metabolites have beneficial effects in the cardiovascular and renal systems. Using immunologic and enzymatic assays, vitamin D receptor and 25 hydroxyvitamin D3 1alpha-hydroxylase activity were found in inner medullary collecting duct (IMCD) cells suggesting an autocrine/paracrine role in this nephron segment. In this study, we examined the ability of 1,25 dihydroxyvitamin D3 (1,25(OH)(2)D3) to regulate the expression of the vasculoprotective natriuretic peptide receptor-A gene in these cells in culture. Treatment of the cells with 1,25(OH)(2)D3 caused a doubling of natriuretic peptide-dependent cyclic guanosine monophosphate production and a significant increase in natriuretic peptide receptor-A protein expression. This was accompanied by significant increases in receptor mRNA levels and gene-promoter activity. Mutation of a vitamin D response element, positioned upstream from the gene start site, resulted in a complete loss of 1,25(OH)(2)D3-dependent induction but not the induction by hypertonic stimuli. Introduction of small interfering RNA directed against the vitamin D receptor into the IMCD cells resulted in decreased natriuretic peptide receptor-A gene promoter activity and protein. The increase in this receptor expression may account for some of the reported beneficial effect of 1,25(OH)(2)D3 on the cardiovascular system and kidney.
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PMID:Vitamin D activates type A natriuretic peptide receptor gene transcription in inner medullary collecting duct cells. 1765 31