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)

E-cadherin, a member of the cadherin family, plays a major role in cell-cell adhesion of normal epithelium. Recent studies have demonstrated that heterogeneous expression, reduction or loss of E-cadherin is involved in invasion and metastasis of cancer cells. In this study, the localization of E-cadherin in the normal human kidney and the relationship between E-cadherin expression and histopathological features in renal cell carcinomas was examined immunohistochemically. Renal cell carcinoma tissues and normal kidney counterparts were obtained from 20 patients. E-cadherin in the normal kidney was detected in the cell-cell border of the distal tubules, collecting duct and Bowman's capsule but not in the proximal tubules. E-cadherin expression was reduced in all the clear cell type renal cell carcinomas with compact or cystic configuration (n = 15), while it was well preserved in all the papillary type (n = 3) and chromophobe cell type (n = 1) renal cell carcinomas. Different expression patterns between primary site and metastasis, i.e., homogeneously weak in primary tumor and heterogeneously positive in metastatis, was observed in a case of clear cell type renal cell carcinoma. Different patterns of expression between clear and non-clear cell type, or between papillary and non-papillary type, together with strong expression in chromophobe type might reflect the origin of each type of renal cell carcinoma. Further studies will clarify whether the change in expression of E-cadherin is associated with the prognosis of renal cell carcinoma.
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PMID:[E-cadherin expression and histopathological features in renal cell carcinomas]. 748 27

CAM expression was investigated immunohistochemically in tissue sections and in pure cultures of human proximal and distal tubular cells. In the fetal kidney, N-CAM immunoreactivity was detected in the non-induced and condensing metanephrogenic mesenchyme, and in all stages until the S-shaped bodies. A-CAM (N-cadherin) first appeared in the non-induced mesenchyme and remained present thereafter. Its expression became exclusively associated with the lower limb of the S-shaped bodies and the developing proximal tubule. In contrast, L-CAM (E-cadherin; uvomorulin) staining was observed in the fetal collecting duct, the upper limb of the S-shaped bodies, and the developing distal tubule. This segment-specific expression of A-CAM and L-CAM in the early developing nephron was maintained in the adult kidney: A-CAM staining was restricted to adherens junctions in the proximal tubule and thin limb, whereas L-CAM was expressed in Bowman's capsule and in all tubular segments except the proximal convoluted and straight tubule. Also after in vitro culture, A-CAM expression was an exclusive property of proximal tubular cells, while L-CAM was confined to distal tubular cells. In conclusion, each major subdivision of the fetal and adult nephron displays a characteristic combination of L-CAM and A-CAM, suggesting that they may be the basis of segmental differentiation and border formation between adjacent nephron segments.
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PMID:Stage- and segment-specific expression of cell-adhesion molecules N-CAM, A-CAM, and L-CAM in the kidney. 835 56

E- and N-cadherins are proteins involved in intercellular adhesion and are localized, e.g., in the adherens junctions of epithelial cells. Kidney tubules express these molecules in a distinctive pattern, the expression of N-cadherin being restricted to proximal tubules and that of E-cadherin to distal tubules and collecting ducts. Renal cell carcinomas (RCCs) and oncocytomas are considered to originate from these tubular epithelia. To find out whether cadherins could serve as markers for a cellular origin of these tumors, we studied the expression of E- and N-cadherins in RCCs and oncocytomas, in cell lines derived from RCCs as well as in tumors grown in nude mice. Most RCCs co-expressed E- and N-cadherins, as did 2 of the 4 cell lines studied. The expression pattern did not correlate with the histological grade of the tumors, and even the least differentiated tumors, as well as metastases, showed expression of cadherins. Renal oncocytomas expressed E-cadherin but not N-cadherin, which is in line with previous studies that have proposed a collecting duct origin for these tumors. Papillary renal neoplasms, a separate entity usually not classified as RCC, expressed neither of the cadherins studied despite the abundant expression of beta-catenin. Our results suggest that most RCCs co-express the characteristic adhesion molecules of both proximal and distal tubules, which makes it questionable whether the origin of these tumors can be reliably located to any distinct part of the renal tubule. Our results also suggest that in RCCs the increased histological grade is not directly associated with changes in the expression of either of the cadherins, indicating other mechanisms underlying the deficient capacity to form polarized tubular structures.
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PMID:Expression of E- and N-cadherin in renal cell carcinomas, in renal cell carcinoma cell lines in vitro and in their xenografts. 855 Feb 43

Cadmium toxicity to renal cells was investigated in Madin-Darby canine kidney (MDCK) and LLC-PK1 cells as models of the distal tubule/collecting duct and proximal tubule, respectively. Cells were grown on two-compartment filters and exposed to 0.1-50 microM Cd2+. In MDCK cells, Cd2+ was more toxic from the basolateral than from the apical side and dependent on the extracellular Ca2+ concentration. Toxicity was evident within 24 h, as shown by a decrease in transepithelial resistance (TER), reduced proliferation (bromodeoxyuridine incorporation), reduction in ATP concentration, and morphological changes. On confocal microscopy, E-cadherin and alpha-catenin staining patterns indicated interference with the cadherin-catenin complex. LLC-PK1 cells showed a similar toxicity pattern, which was evident at lower Cd2+ concentrations. An increase of E-cadherin and alpha-catenin molecules in the Triton X-100-insoluble fraction was detectable at high Cd2+ concentrations in LLC-PK1 cells but not in MDCK cells. Lactate dehydrogenase release indicated membrane leakage in LLC-PK1 cells. Rhodamine-phalloidin staining, a probe for F-actin filaments, demonstrated alterations of the actin cytoskeleton in both cell lines. In conclusion, cadmium caused ATP depletion and interfered with the cadherin-catenin complex and probably the tight junctions changing renal cell morphology and function.
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PMID:Cadmium is more toxic to LLC-PK1 cells than to MDCK cells acting on the cadherin-catenin complex. 968 16

Chromophobe renal cell carcinoma (RCC) is a newly established category of RCC composed histologically of characteristic "chromophobe" tumor cells. Although ultrastructural and immunohistochemical studies showed that these tumor cells present several features similar to those found in the intercalated cells of the collecting duct, immunohistochemical studies using antibody panels on a large number of cases are limited. We performed an immunohistochemical study of 21 Japanese cases of chromophobe RCC, along with cases of clear RCC and renal oncocytoma, to find hallmarks useful for precise differential diagnosis of these tumors. Chromophobe RCC was positive for epithelial membrane antigen but negative for vimentin. Cytokeratins did not show constant immunoreactivity in the three types of renal tumors. Furthermore, all of the chromophobe RCCs and renal oncocytomas were positive for E-cadherin but not for N-cadherin, whereas all of the clear RCCs were negative for E-cadherin, and 58% were positive for N-cadherin. The Ki-67 labeling indices were significantly lower in cases classified as (pT1) or Grade 2 chromophobe RCC than in cases of clear RCC. Immunoreaction for E-cadherin was demonstrated to be useful for distinguishing chromophobe RCC from clear RCC, and a low Ki-67 labeling index might indicate a favorable prognosis, as reported in several previous studies.
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PMID:Chromophobe renal cell carcinoma: an immunohistochemical study of 21 Japanese cases. 1010 17

Epithelial cell morphology and cytoskeletal organization are determined by interactions, with both adjacent cells and the extracellular matrix, which are mediated by integrins and cadherins. Little is known, however, of the relative contributions of integrins and cadherins to maintaining the sub-cortical cytoskeleton characteristic of epithelial cells. Since most studies that utilize integrin-blocking antibodies result in a loss of both cell-cell adhesion and sub-cortical cytoskeletal organization, it has been difficult to distinguish whether integrins and cadherins both mediate cytoskeletal assembly in epithelial cells. Therefore, cells derived from kidney collecting ducts of (alpha)3(beta)1 integrin-deficient mice were used to examine the role of integrins in epithelial cell morphology and cytoskeletal organization. In primary cell culture, (alpha)3(beta)1 integrin-deficient kidney collecting duct cells maintain cadherin-mediated cell-cell adhesions but fail to form the sub-cortical cytoskeleton that is characteristic of epithelial cells, and instead assemble actin stress fibers. Moreover, the cell-cell junctions in mutant cells were irregular, rather than being uniformly oriented perpendicular to the culture substrate. These results demonstrated that integrins have an primary and essential function in establishing and maintaining the sub-cortical cytoskeleton that is characteristic of epithelial cells. To further study the role of (alpha)3(beta)1 integrin in establishing and maintaining cytoskeletal organization in tubular epithelial cells, we derived immortalized cell lines from wild-type and (alpha)3(beta)1 integrin-deficient kidney collecting ducts that duplicated the cytoskeletal and cadherin organization observed in primary cells. E-cadherin and (alpha)- and (beta)-catenin were complexed together in equal amounts in membranes of wild-type and (alpha)3(beta)1 integrin-deficient cells. However, association of the cadherin:catenin complex with (alpha)-actinin was greatly decreased in mutant cells, indicating that integrin-mediated assembly of the sub-cortical cytoskeleton is essential for subsequent association of the cytoskeleton with the cadherin:catenin complex. These results present direct evidence for integrin:cadherin cross-regulation in which cadherin function is dependent on the presence of an integrin.
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PMID:(Alpha)3(beta)1 integrin regulates epithelial cytoskeletal organization. 1044 87

To distinguish common epithelial tumors arising in the kidney may have significant implications, in terms of molecular ontogeny and prognosis. It is important to investigate the distribution of immunoexpression of commonly used markers among renal neoplasms and to develop a useful panel as an adjunct to histologic examination, which could lead to the accurate diagnosis of both primary and metastatic tumors. Immunohistochemical stains for CD10, vimentin (VIM), E-cadherin (E-CD), cytokeratins (CK) 7, 8, 19, and 20, high molecular weight keratin (HCK), and peanut lectin agglutinin (PL) (Arachis hypogaea) were performed on 45 (96 for CK7, CK20) conventional (CC), 20 papillary (PC), and 6 (24 for CK7, CK20) chromophobe renal carcinomas (CPC); 12 oncocytomas (OC); 5 collecting duct carcinomas (CDC), and 25 urothelial carcinomas of the renal pelvis (UC). Reactivity for CD10 was evaluated on the basis of the presence of cell surface staining; that for all CKs, cytoplasmic/membranous staining; and that for PL, luminal staining. Both CD10 and VIM were predominantly expressed in CC and PC; E-CD in CPC, OC, and UC; CK7 in PC, CPC, and UC; CK8 and CK19 in CDC and UC; CK20 in UC; HCK in CDC and UC; and PL in CDC. CC and OC were predominantly CK7-/CK20-; PC, CK7+/20-; CPC, CK7+/CK20- or CK7-/CK20-; and UC, CK7+/CK20- or CK7+/CK20+. CDC showed slight predominance of CK7-/20- over CK7+/CK20-. CC was most frequently CD10+/CK7-/HCK-/PL-; PC, CD10+/CK7+/HCK-/PL-; CPC, CD10-/CK7+/HCK-/PL-; OC, CD10-/CK7-/HCK-/ PL-; CDC, CD10-/CK7+/HCK-/PL+ or CD10-/CK7-/ HCK+/PL+; and UC, CD10-/CK7+/HCK+/PL-. Discriminant analysis suggested that CD10/CK7/HCK/PL may be a useful primary immunopanel for distinguishing among CC, PC, CDC, and UC.
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PMID:Immunohistochemical profile of common epithelial neoplasms arising in the kidney. 1261 43

There are few published reports of low-grade renal epithelial tumor originating from the distal nephron. However, it should not be disregarded clinically, because the actual number of patients with such tumors may be higher than expected. We investigated the immunohistochemical profile of a histologically distinct subtype of such a tumor in detail, in addition to the clinical course and imaging studies. The present study demonstrated that both glandular and spindle cell components of this tumor have a persistent characteristic of an epithelial tumor arising from the distal tubule or collecting duct. This tumor is a benign complex neoplasm that can be treated successfully with radical surgery. Beta-catenin and E-cadherin are suggested to play a crucial role in tumorigenesis and the biphasic arrangement of this neoplasm, concerning the expression of epithelial membrane antigen and carbohydrate antigen 19-9. We suggest that the term 'distal nephron epithelioma' is appropriate for classifying such rare but clinicopathologically distinct tumors.
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PMID:Low-grade renal epithelial tumor originating from the distal nephron. 1566 96

Binding of arginine-vasopressin (AVP) to its V2 receptor (V2R) in the basolateral membrane of principal cells induces Aquaporin-2-mediated water reabsorption in the kidney. To study the regulation of the V2R by dDAVP in a proper model, a polarized renal cell line stably-expressing V2R-GFP was generated. Labeled AVP-binding studies revealed an equal basolateral vs. apical membrane distribution for V2R-GFP and endogenous V2R. In these cells, GFP-V2R was expressed in its mature form and localized for 75% in the basolateral membrane and for 25% to late endosomes/lysosomes. dDAVP caused a dose- and time-dependent internalization of V2R-GFP, which was completed within 1 h with 100 nM dDAVP, was prevented by coincubation with a V2R antagonist, and which reduced its half-life from 11.5 to 2.8 h. Semiquantification of the V2R-GFP colocalization with E-cadherin (basolateral membrane), early endosomal antigen-1 (EEA-1) and lysosome-associated membrane protein-2 (LAMP-2) in time revealed that most dDAVP-bound V2R was internalized via early endosomes to late endosomes/lysosomes, where it was degraded. The dDAVP-internalized V2R did not recycle to the basolateral membrane. In conclusion, we established the itinerary of the V2R in a polarized cell model that likely resembles the in vivo V2R localization and regulation by AVP to a great extent.
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PMID:Regulation of the vasopressin V2 receptor by vasopressin in polarized renal collecting duct cells. 1546 88

FXYD5 (related to ion channel, dysadherin) is a member of the FXYD family of single span type I membrane proteins. Five members of this group have been shown to interact with the Na,K-ATPase and to modulate its properties. However, FXYD5 is structurally different from other family members and has been suggested to play a role in regulating E-cadherin and promoting metastasis (Ino, Y., Gotoh, M., Sakamoto, M., Tsukagoshi, K., and Hirohashi, S. (2002) Proc. Natl. Acad. Sci. U. S. A. 99, 365-370). The goal of this study was to determine whether FXYD5 can modulate the Na,K-ATPase activity, establish its cellular and tissue distribution, and characterize its biochemical properties. Anti-FXYD5 antibodies detected a 24-kDa polypeptide that was preferentially expressed in kidney, intestine, spleen, and lung. In kidney, FXYD5 resides in the basolateral membrane of the connecting tubule, the collecting tubule, and the intercalated cells of the collecting duct. However, there is also labeling of the apical membrane in long thin limb of Henle's loop. FXYD5 was effectively immunoprecipitated by antibodies to the alpha subunit of Na,K-ATPase and the anti-FXYD5 antibody immunoprecipitates alpha. Co-expressing FXYD5 with the alpha1 and beta1 subunits of the Na,K-ATPase in Xenopus oocytes elicited a more than 2-fold increase in pump activity, measured either as ouabain-blockable outward current or as ouabain-sensitive (86)Rb(+) uptake. Thus, as found with other FXYD proteins, FXYD5 interacts with the Na,K-ATPase and modulates its properties.
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PMID:Interaction with the Na,K-ATPase and tissue distribution of FXYD5 (related to ion channel). 1614 1


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