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)

Barrier epithelia such as the renal collecting duct (in the absence of antidiuretic hormone) and thick ascending limb, as well as the stomach and mammalian bladder, exhibit extremely low permeabilities to water and small nonelectrolytes. A cell culture model of such epithelia is needed to determine how the structure of barrier apical membranes reduce permeability and how such membranes may be generated and maintained. In the present studies, the transepithelial electrical resistance and isotopic water and urea fluxes were measured for Madin-Darby canine kidney (MDCK) type I and type II cells, as well as type I cells expressing the mucin protein, MUC1, in their apical membranes. Although earlier studies had found the unstirred layer effects too great to permit measurement of transepithelial permeabilities, use of ultrathin semipermeable supports in this study overcame this difficulty. Apical membrane diffusive water permeabilities were 1.8 +/- 0.4 x 10(-4) cm/s and 3.5 +/- 0.5 x 10(-4) cm/s in MDCK type I and type II cells, respectively, at 20 degrees C. Urea permeability in type I cells at the same temperature was 6.0 +/- 0.9 x 10(-6) cm/s. These values resemble those of other barrier epithelial apical membranes, either isolated or in intact epithelia, and the water permeability values are far below those of other epithelial cells in culture. Transfection of MDCK type I cells with the major human urinary epithelial mucin, MUC1, led to abundant expression of the fully glycosylated form of the protein on immunoblots, and flow cytometry revealed that virtually all the cells expressed the protein. However, MUC1 had no effect on water or urea permeabilities. In conclusion, MDCK cells grown on semipermeable supports form a model barrier epithelium. Abundant expression of mucins does not alter the permeability properties of these cells.
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PMID:Low permeabilities of MDCK cell monolayers: a model barrier epithelium. 924 93

The expression of MUC1, MUC2, mucin-associated Thomsen-Friedenreich-related antigens (TF, sialosyl-TF, Tn, and sialosyl-Tn), and cytokeratin 19 (CK19) was systematically investigated in situ in 58 resected human kidney tumours, surrounding tissue of normal appearance, and two normal kidneys obtained at autopsy, using monoclonal antibodies. In kidney tissues of normal appearance, TF, s-TF, MUC1 and CK19 were positive in distal tubules and collecting ducts but negative in proximal tubules. In contrast, MUC2, Tn, and s-Tn were negative throughout the normal renal tubular system. Almost all renal cell carcinomas (RCCs) showed strong immunoreactivity for MUC1, but all were negative for MUC2. Some RCCs expressed TF, Tn, s-Tn, and CK19. In addition, the immunomorphological characteristics of the majority of clear-cell RCCs and clear/granular RCCs with anti-MUC1 and anti-CK 19 closely resembled those of the collecting duct and the distal tubule rather than the proximal tubule. In the renal tissue of otherwise normal appearance adjacent to clear-cell RCCs and clear/granular RCCs, clear cells with excessive storage of glycogen were often found in the collecting duct system, but only rarely in the proximal tubules. These results suggest that the majority of clear-cell RCCs and clear/granular RCCs may originate from the collecting duct system.
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PMID:Expression of MUC1, Thomsen-Friedenreich-related antigens, and cytokeratin 19 in human renal cell carcinomas and tubular clear cell lesions. 1075 1

The presence of cytoplasmic sialyl glycoproteins is a conspicuous feature in chromophobe renal cell carcinoma (RCC). We compared the immunohistochemical expression of sialyl glycoproteins in chromophobe RCC with that in other types of renal tumors. Formalin-fixed, paraffin-embedded tissues of surgically resected renal tumors (chromophobe RCC, 14 cases [10 cases of classic type and 4 cases of eosinophilic variant]; oncocytoma, 7 cases; and clear cell RCC, 9 cases) and kidneys from immature infants (4 cases) were immunostained with antibodies against sialyl glycoproteins (anti-KL-6 and anti-sialyl MUC1 antibodies). Cytoplasmic expression of KL-6 and sialyl MUC1 was distinctive in the chromophobe RCC and renal oncocytoma cells, and in the intercalated cells in collecting duct epithelia. Apical-surface staining of these sialyl glycoproteins was predominantly observed in clear RCC, in the epithelia of the distal tubule and collecting duct, and in the neonatal renal proximal tubule, but not in those of the adult renal proximal tubule. The above-mentioned observations provide additional evidence for similar phenotypic profiles of chromophobe RCC and renal oncocytoma, and the intercalated cells in collecting ducts and the oncofetal expression of sialyl glycoproteins in clear cell RCC. KL-6 is a potential tumor marker for renal tumors.
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PMID:Distinct Cytoplasmic Expression of KL-6 Mucin in Chromophobe Renal Cell Carcinoma: A Comparative Immunohistochemical Study with Other Renal Epithelial Cell Tumors. 2320 39