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Query: UNIPROT:P41181 (collecting duct)
 5,183 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study describes the establishment of a rat kidney cortical collecting duct (CCD) clonal cell line (RCCD1 cells) that maintains high transepithelial resistance and specific hormonal sensitivities. Immortalized cells were obtained by infection of primary cultured CCD cells with the wild-type simian virus 40. Grown on Petri dishes, RCCD1 cells are organized as monolayers of cuboid cells separated by tight junctions and form domes. Grown on permeable filters, confluent RCCD1 cells exhibit high transepithelial resistance (Rt: 2390 +/- 140 omega. cm2), transepithelial potential difference (PD) of -10.5 +/- 1.2 mV lumen negative, an associated short-circuit current (Isc) of 4.3 +/- 0.5 microA/cm2, and generated significant Na+, K+, H+ and HCO3- gradients, reflecting Na+ and H+ reabsorption and K+ and HCO3- secretion. RCCD1 cells exhibit features of both principal (PC) and intercalated (IC) cells. Consistent with PC phenotype, about 50% of the cells were positively stained by a PC-specific agglutinin. In situ hybridization studies revealed the presence of alpha, beta and gamma subunit mRNAs of the amiloride-sensitive epithelial Na+ channel and alpha 1 and beta 1 subunits of Na(+)-K(+)-ATPase. Moreover, Na(+)-K(+)-ATPase was immunolocalized at the basolateral side of the cells. Arginine vasopressin (AVP) induced a significant increase in both cellular cAMP content and Isc. Amiloride decreased in a dose-dependent manner Isc from untreated and AVP-treated RCCD1 cells. In addition, a barium-sensitive K+ conductance was evidenced in the apical side of the cells. Consistent with IC phenotype, isoproterenol (ISO) provoked a large increase in cellular cAMP and stimulated Isc. The effect of ISO on Isc was blocked by 5 x 10(-3) M DPC, a chloride channel blocker. Finally, AVP plus ISO had additive effect on Isc. Taken together, these results provide evidence that the RCCD1 cell line has maintained many of the original properties of rat CCD from which they were derived.
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PMID:Characteristics of a rat cortical collecting duct cell line that maintains high transepithelial resistance. 884 Feb 62

We have examined whether arginine vasopressin (AVP) can induce a long-term modulation of transepithelial ion transport in addition to its well known short-term effect. In the RCCD1 rat cortical collecting duct cell line, an increase in both short-circuit current and 22Na transport was observed after several hours of 10(-8) M AVP treatment (a concentration above the in vivo physiological range). This delayed effect was partially prevented by apical addition of 10(-5) M amiloride and was blocked by 10(-6) M actinomycin D and 2 x 10(-6) M cycloheximide. The amounts of mRNA encoding the alpha1 (not beta1) subunit of Na+/K+-ATPase and the beta and gamma (not alpha) subunits of the amiloride-sensitive epithelial Na+ channel were significantly increased by AVP treatment. The increase in mRNA was blocked by actinomycin D, not by amiloride, suggesting a Na+-independent increase in the rate of transcription of these subunits. The translation rates of the alpha1 subunit of Na+/K+-ATPase and the beta and gamma subunits of the rat epithelial sodium channel increased significantly, whereas the translation rates of the other subunits remained unchanged. Finally, the number of Na+ channels present in the apical membrane of the cells increased, as demonstrated by enhanced specific [3H]phenamil binding.
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PMID:Transcriptional regulation of sodium transport by vasopressin in renal cells. 940 70

We have examined the respective influence of aldosterone, vasopressin and cell sodium delivery on Na+,K+-ATPase expression. The level of expression of the mRNA encoding for the alpha1- and beta1-subunits of Na+,K+-ATPase was evaluated in cortical collecting duct (CCD) cells from rats under different aldosterone status, in cells from the rat CCD cell line RCCD1 treated or not with vasopressin and in CCD cells from mice inactivated or not for the a-subunit of the epithelial sodium channel. The amount of mRNA was determined by in situ hybridization. Both aldosterone and vasopressin up-regulate transcripts encoding for the alpha1-subunit of Na+,K+-ATPase while beta1 is unaltered. Interestingly, when cell sodium entry was largely reduced (alphaENaC knock-out mice), the amount of transcripts encoding for the alpha1-subunit of Na+,K+-ATPase was significantly decreased in spite of high plasma aldosterone concentrations. No effect was observed on beta1-subunit. Altogether, these results suggest a coordinated hormonal and ionic control of Na+,K+-ATPase expression by different transcriptional pathways (steroid-receptor, cAMP-dependent and Na+dependent) in CCD cells. These regulations affect only alpha1-subunit of Na,K+-ATPase but not beta1.
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PMID:Coordinate control of Na,K-atpase mRNA expression by aldosterone, vasopressin and cell sodium delivery in the cortical collecting duct. 1135 97

The renal collecting duct (CD) plays a key role in the control of ion and fluid homeostasis. Several genetic diseases that involve mutations in genes encoding for ion transporters or hormone receptors specifically expressed in CD have been described. Suitable cellular or transgenic animal models expressing such mutated genes in an inducible manner should represent attractive systems for structure-function relationship analyses and the generation of appropriate physiopathological models of related diseases. Our first goal was to develop a CD cell line that allows inducible gene expression using the tetracycline-inducible system (Tet-On). We designed several strategies aimed at the development of a tight and highly inducible system in RCCD1 cells, a rat cortical collecting duct (CCD) cell line exhibiting several properties of the native CCD. Analysis of reporter gene expression demonstrated that the Tet-On system is suitable for inducible gene expression in these cells. In a second step, we have tested whether transgenic Tet-On mice expressing the tetracycline transactivator under the control of the human cytomegalovirus promoter were suitable for inducible gene expression in tubule epithelial cells. The results indicate that, in vivo, the inducible expression of the lacZ reporter gene appeared to be restricted to the CD. This particular strain of transgenic mice may therefore be useful for the expression of genes of interest in an inducible manner in the collecting duct.
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PMID:Tetracycline-inducible gene expression in cultured rat renal CD cells and in intact CD from transgenic mice. 1170 69

The Na+/H+ exchanger (NHE) constitutes a gene family containing several isoforms that display different membrane localization and are involved in specialized functions. Although basolateral NHE-1 activity was described in the cortical collecting duct (CCD), the localization and function of other NHE isoforms is not yet clear, This study examines the expression, localization, and regulation of NHE isoforms in a rat cortical collecting duct cell line (RCCD1) that has previously been shown to be a good model of CCD cells. Present studies demonstrate the presence of NHE-1 and NHE-2 isoforms, but not NHE-3 and NHE-4, in RCCD1 cells. Cell monolayers, grown on permeable filters, were placed on special holders allowing independent access to apical and basolateral compartments. Intracellular pH (pHi) regulation was spectrofluorometrically studied in basal conditions and after stimulation by NH4Cl acid load or by a hyperosmotic shock. In order to differentiate the roles of NHE-1 and NHE-2, we have used HOE-694, an inhibitor more selective for NHE-1 than for NHE-2. The results obtained strongly suggest that NHE-1 and NHE-2 are expressed in the basolateral membrane but that they have different roles: NHE-1 is responsible for pHi recovery after an acid load and NHE-2 is mainly involved in steady-state pHi and cell volume regulation.
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PMID:Differential role of Na+/H+ exchange isoforms NHE-1 and NHE-2 in a rat cortical collecting duct cell line. 1247 76

The Cl(-)/HCO3- exchanger (AE) is one of the mechanisms that cells have developed to adjust pH Despite its importance, the role of AE isoforms in controlling steady-state pH during alkalosis has not been widely investigated. In the present study, we have evaluated whether conditions simulating acute and chronic metabolic alkalosis affected the transport activity and protein levels of Cl-/HCO3- exchangers in a rat cortical collecting duct cell line (RCCD1). pH(i) was monitored using the fluorescent dye BCECF in monolayers grown on permeable supports. Anion exchanger function was assessed by the response of pH(i) to acute chloride removal. RT-PCR and immunoblot assays were also performed. Our results showed that RCCD1 cells express two members of the anion exchanger gene family: AE2 and AE4. Functional studies demonstrated that while in acute alkalosis pH(i) became alkaline and was not regulated, after 48 h adaptation; steady-state pH(i) reached a value similar to the physiological one. Chronic treated cells also resulted in a 3-fold rise in Cl(-)/HCO3- exchange activity together with a 2.2-fold increase in AE2, but not AE4, protein abundance. We conclude that RCCD1 cells can adapt to chronic extracellular alkalosis reestablishing its steady-state pH(i) and that AE2 would play a key role in cell homeostasis.
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PMID:Functional and molecular adaptation of Cl/HCO3- exchanger to chronic alkaline media in renal cells. 1630 27