Potassium Transport in the Mammalian Collecting Duct

2001 ◽  
Vol 81 (1) ◽  
pp. 85-116 ◽  
Author(s):  
Shigeaki Muto
Keyword(s):  
Driving Forces ◽  
Collecting Duct ◽  
Dominant Role ◽  
Duct Cell ◽  
Cell Types ◽  
Cortical Collecting Duct ◽  
Membrane Conductances ◽  
Collecting Duct Cells

The mammalian collecting duct plays a dominant role in regulating K+ excretion by the nephron. The collecting duct exhibits axial and intrasegmental cell heterogeneity and is composed of at least two cell types: collecting duct cells (principal cells) and intercalated cells. Under normal circumstances, the collecting duct cell in the cortical collecting duct secretes K+, whereas under K+ depletion, the intercalated cell reabsorbs K+. Assessment of the electrochemical driving forces and of membrane conductances for transcellular and paracellular electrolyte movement, the characterization of several ATPases, patch-clamp investigation, and cloning of the K+ channel have provided important insights into the role of pumps and channels in those tubule cells that regulate K+ secretion and reabsorption. This review summarizes K+ transport properties in the mammalian collecting duct. Special emphasis is given to the mechanisms of how K+ transport is regulated in the collecting duct.

Polaris, a protein disrupted inorpkmutant mice, is required for assembly of renal cilium

2002 ◽  
Vol 282 (3) ◽  
pp. F541-F552 ◽  
Author(s):  
Bradley K. Yoder ◽  
Albert Tousson ◽  
Leigh Millican ◽  
John H. Wu ◽  
Charles E. Bugg ◽  
...  
Keyword(s):  
Primary Cilia ◽  
Collecting Duct ◽  
Physiological Role ◽  
Duct Cell ◽  
Cystic Kidney Disease ◽  
Cystic Kidney ◽  
Apical Surface ◽  
Cystic Disease ◽  
Cortical Collecting Duct

Cilia are organelles that play diverse roles, from fluid movement to sensory reception. Polaris, a protein associated with cystic kidney disease in Tg737°rpkmice, functions in a ciliogenic pathway. Here, we explore the role of polaris in primary cilia on Madin-Darby canine kidney cells. The results indicate that polaris localization and solubility change dramatically during cilia formation. These changes correlate with the formation of basal bodies and large protein rafts at the apical surface of the epithelia. A cortical collecting duct cell line has been derived from mice with a mutation in the Tg737 gene. These cells do not develop normal cilia, which can be corrected by reexpression of the wild-type Tg737 gene. These data suggest that the primary cilia are important for normal renal function and/or development and that the ciliary defect may be a contributing factor to the cystic disease in Tg737°rpkmice. Further characterization of these cells will be important in elucidating the physiological role of renal cilia and in determining their relationship to cystic disease.

Role of AQP2 during apoptosis in cortical collecting duct cells

2009 ◽  
Vol 101 (4) ◽  
pp. 237-250 ◽  
Author(s):  
Pilar Flamenco ◽  
Luciano Galizia ◽  
Valeria Rivarola ◽  
Juan Fernandez ◽  
Paula Ford ◽  
...  
Keyword(s):  
Collecting Duct ◽  
Cortical Collecting Duct ◽  
Duct Cells ◽  
Collecting Duct Cells

Adaptation to alkalosis induces cell cycle delay and apoptosis in cortical collecting duct cells: Role of aquaporin-2

2010 ◽  
Vol 224 (2) ◽  
pp. 405-413 ◽  
Author(s):  
Valeria Rivarola ◽  
Pilar Flamenco ◽  
Luciana Melamud ◽  
Luciano Galizia ◽  
Paula Ford ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Collecting Duct ◽  
Cortical Collecting Duct ◽  
Cell Cycle Delay ◽  
Aquaporin 2 ◽  
Duct Cells ◽  
Collecting Duct Cells

Functional characterization of alpha- and beta-intercalated cell types in rabbit cortical collecting duct

1991 ◽  
Vol 261 (3) ◽  
pp. F377-F385 ◽  
Author(s):  
H. Furuya ◽  
M. D. Breyer ◽  
H. R. Jacobson
Keyword(s):  
Collecting Duct ◽  
Basolateral Membrane ◽  
Functional Characterization ◽  
Cell Types ◽  
Disulfonic Acid ◽  
Cortical Collecting Duct ◽  
Electrical Measurements ◽  
Collecting Ducts

Single-cell electrical measurements and spectrophotometric determinations of intracellular pH were used to determine unique features of alpha- and beta-intercalated cells (alpha-IC, beta-IC) in in vitro perfused rabbit cortical collecting ducts (CCD). pHi rose in alpha-IC and fell in beta-IC after bath Cl- removal. Luminal Cl- removal did not change pHi of alpha-IC, but pHi of beta-IC rose by 0.36 +/- 0.01 pH units. Cl- concentration-dependent recovery of beta-IC pHi revealed a Cl- Km of 18.7 mM for the luminal Cl(-) -HCO3- exchanger. Measurements of basolateral membrane voltage (Vbl) also showed two IC cell types. Removal of luminal Cl- did not change Vbl in alpha-IC, whereas Vbl hyperpolarized by a mean of 73.2 +/- 3.5 mV in beta-IC. Reducing bath Cl- depolarized both alpha- and beta-IC Vbl. In alpha-IC a large repolarization of 39.8 +/- 5.2 mV followed acute depolarization after bath Cl- removal. Reducing bath HCO3- (constant CO2) had little effect on beta-IC Vbl, whereas alpha-IC Vbl depolarized by 5.2 +/- 0.7 mV. Reducing luminal HCO3- in the absence of luminal Cl- produced a 17.6 +/- 1.8 mV depolarization in beta-IC. This change was independent of luminal Na+ and was not blocked by luminal 10(-4) M 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). In beta-IC, Vbl was not altered by either bath or lumen DIDS in the presence of luminal Cl-. However, when luminal Cl- was removed, luminal DIDS reversibly depolarized Vbl by 9.6 +/- 2.9 mV.(ABSTRACT TRUNCATED AT 250 WORDS)

Chloroquine attenuates lithium-induced NDI and proliferation of renal collecting duct cells

2020 ◽  
Vol 318 (5) ◽  
pp. F1199-F1209 ◽  
Author(s):  
Yang Du ◽  
Yun Qian ◽  
Xiaomei Tang ◽  
Yan Guo ◽  
Shuang Chen ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Collecting Duct ◽  
Mammalian Target Of Rapamycin ◽  
Duct Cell ◽  
Nuclear Antigen ◽  
Kidney Cortex ◽  
Cortical Collecting Duct ◽  
Aquaporin 2 ◽  
Duct Cells ◽  
Collecting Duct Cells

Lithium is widely used in psychiatry as the golden standard for more than 60 yr due to its effectiveness. However, its adverse effect has been limiting its long-term use in clinic. About 40% of patients taking lithium develop nephrogenic diabetes insipidus (NDI). Lithium can also induce proliferation of collecting duct cells, leading to microcyst formation in the kidney. Lithium was considered an autophagy inducer that might contribute to the therapeutic benefit of neuropsychiatric disorders. Thus, we hypothesized that autophagy may play a role in lithium-induced kidney nephrotoxicity. To address our hypothesis, we fed mice with a lithium-containing diet with chloroquine (CQ), an autophagy inhibitor, concurrently. Lithium-treated mice presented enhanced autophagy activity in the kidney cortex and medulla. CQ treatment significantly ameliorated lithium-induced polyuria, polydipsia, natriuresis, and kaliuresis accompanied with attenuated downregulation of aquaporin-2 and Na+-K+-2Cl− cotransporter protein. The protective effect of CQ on aquaporin-2 protein abundance was confirmed in cultured cortical collecting duct cells. In addition, we found that lithium-induced proliferation of collecting duct cells was also suppressed by CQ as detected by proliferating cell nuclear antigen staining. Moreover, both phosphorylated mammalian target of rapamycin and β-catenin expression, which have been reported to be increased by lithium and associated with cell proliferation, were reduced by CQ. Taken together, our study demonstrated that CQ protected against lithium-induced NDI and collecting duct cell proliferation possibly through inhibiting autophagy.

Abstract P117: A Conserved Trans-membrane Domain Lysine in the Integrin Beta1 Subunit Regulates Renal Collecting Duct Cell Function

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Sijo Mathew ◽  
Jiang Chen ◽  
Zhenwei Lu ◽  
Charles Sanders ◽  
Roy Zent
Keyword(s):  
Cell Function ◽  
Collecting Duct ◽  
Duct Cell ◽  
Lysine Residue ◽  
Mutant Protein ◽  
Integrin Β1 ◽  
Binding Ability ◽  
Integrin Β3 ◽  
Collecting Duct Cells

Integrins are heterodimeric trans-membrane receptor proteins that mediate the interaction of cells with extracellular matrix proteins (ECM). They mediate various growth factor dependent cell-signaling pathways during the development of fibrosis that is characteristic of all forms of chronic kidney diseases. Although integrin β1 is the most abundant integrin subunit in kidney and can form complexes with 12 different α subunits, integrin β3 is the best studied integrin β subunit and serves as the canonical model for integrin function based on the high sequence homology between the trans-membrane and cytosolic domains of integrin β subunits. A conserved lysine residue towards the C-terminus of integrin β3 subunit is reported to be important for regulating the activation of integrin αIIbβ3 complexes; however the functional importance of this lysine is unknown in β1 integrins. We investigated the role of this lysine residue in integrin β1-dependent kidney collecting duct cell function. We expressed the mutant protein where the lysine is mutated to glutamic acid in collecting duct cells null for integrin β1. Collecting duct cells expressing mutant protein had decreased the adhesion of cells to collagen IV mediated by integrin α1β1 by 80% (0.95 vs 0.18). This mutation also decreased the ability of IMCD cells adhesion to collagen I mediated by integrin α2β1 by 82% (0.78 vs 0.15). In contrast to earlier reports in integrin β3, this mutation did not significantly alter the amount of active integrin β1 on the cell surface as estimated by FACS analysis; however we did observe a decrease in conformation specific antibody binding on cells adhered to collagen (0.70 vs 0.30). We also investigated the role of this lysine residue in complex formation of purified integrin β1 with integrin α1 and α2 TM/CT domains in phospholipid bicelles using fluorescence anisotropy. The dissociation constant for binding was estimated to be >3.2 mol and mutation of lysine residue did not significantly alter their binding ability. This contrasted with integrin αIIb β3 where we found fourfold decrease in binding ability (Kd 0.09 ± 0.03 mol and 0.33 ± 0.05 mol). Our data clearly suggest that conserved transmembrane lysine in both integrin β3 and integrin β1 regulate cell functions by distinct mechanisms.

CFTR expression in cortical collecting duct cells

1996 ◽  
Vol 270 (1) ◽  
pp. F237-F244 ◽  
Author(s):  
K. M. Todd-Turla ◽  
E. Rusvai ◽  
A. Naray-Fejes-Toth ◽  
G. Fejes-Toth
Keyword(s):  
Collecting Duct ◽  
Cell Types ◽  
Northern Analysis ◽  
Transmembrane Conductance Regulator ◽  
Cortical Collecting Duct ◽  
Transmembrane Conductance ◽  
Pcr Product ◽  
Pcr Products ◽  
Collecting Duct Cells ◽  
Cystic Fibrosis Transmembrane

The cystic fibrosis transmembrane conductance regulator (CFTR) is a adenosine 3',5'-cyclic monophosphate-activated chloride channel located in the apical membrane of many epithelial cells, and it may play a significant role in the kidney. Recent functional evidence from our laboratory suggests that CFTR may be expressed by the cortical collecting duct (CCD). Therefore, in the present study, the reverse transcription-polymerase chain reaction (RT-PCR) technique was utilized to detect CFTR mRNA in the M-1 mouse CCD cell line and in immunoselected rabbit CCD cells. Primers were constructed to amplify the cDNA sequence encoding the first nucleotide binding domain of CFTR. CFTR PCR products were obtained from both M-1 and rabbit CCD cDNA preparations. The identify of the product amplified from M-1 cell cDNA was confirmed by restriction digestion analysis. The rabbit CCD PCR product was sequenced, and its deduced amino acid sequence was found to be 97% homologous to the corresponding regions of human CFTR. The level of CFTR cDNA detected after 30 cycles of amplification of CCD cDNA was only 49 +/- 8 (n = 9) times lower than the level of beta-actin PCR product obtained from the same sample, suggesting that the levels of CFTR mRNA present in the CCD are physiologically relevant. Northern analysis, using a cRNA probe corresponding to the amplified region on the mRNA from CCD cells, revealed a single hybridizing species with a size of approximately 6.5 kb. Finally, CFTR PCR was performed with cDNA preparations originating from principal cells (PC), beta-intercalated cells (beta-ICC), and alpha-ICC obtained by fluorescence-activated cell sorting of rabbit CCD. CFTR PCR products were obtained from all three cell types, with the most abundant levels found in beta-ICC. beta-ICC expressed 25-fold (n = 4, P < 0.001) and 4.5-fold (n = 7, P < 0.001) higher levels than PC and alpha-ICC, respectively. This distribution pattern suggests that, within the CCD, CFTR plays a role primarily in beta-ICC function.

scholarly journals RNA sequencing of kidney distal tubule cells reveals multiple mediators of chronic aldosterone action

2018 ◽  
Vol 50 (5) ◽  
pp. 343-354 ◽  
Author(s):  
Søren Brandt Poulsen ◽  
Kavee Limbutara ◽  
Robert A. Fenton ◽  
Trairak Pisitkun ◽  
Birgitte Mønster Christensen
Keyword(s):  
Rna Sequencing ◽  
Collecting Duct ◽  
Distal Tubule ◽  
Cell Types ◽  
Sodium Reabsorption ◽  
Specific Cell ◽  
Cortical Collecting Duct ◽  
Principal Cells ◽  
Mrna Transcriptome

The renal aldosterone-sensitive distal tubule (ASDT) is crucial for sodium reabsorption and blood pressure regulation. The ASDT consists of the late distal convoluted tubule (DCT2), connecting tubule (CNT), and collecting duct. Due to difficulties in isolating epithelial cells from the ASDT in large quantities, few transcriptome studies have been performed on this segment. Moreover, no studies exist on isolated DCT2 and CNT cells (excluding intercalated cells), and the role of aldosterone for regulating the transcriptome of these specific cell types is largely unknown. A mouse model expressing eGFP in DCT2/CNT/initial cortical collecting duct (iCCD) principal cells was exploited to facilitate the isolation of these cells in high number and purity. Combined with deep RNA sequencing technology, a comprehensive catalog of chronic aldosterone-regulated transcripts from enriched DCT2/CNT/iCCD principal cells was generated. There were 257 significantly downregulated and 290 upregulated transcripts in response to aldosterone ( P < 0.05). The RNA sequencing confirmed aldosterone regulation of well-described aldosterone targets including Sgk1 and Tsc22d3. Changes in selected transcripts such as S100a1 and Cldn4 were confirmed by RT-qPCR. The RNA sequencing showed downregulation of Nr3c2 encoding the mineralocorticoid receptor (MR), and cell line experiments showed a parallel decrease in MR protein. Furthermore, a large number of transcripts encoding transcription factors were downregulated. An extensive mRNA transcriptome reconstruction of an enriched CNT/iCCD principal cell population was also generated. The results provided a comprehensive database of aldosterone-regulated transcripts in the ASDT, allowing development of novel hypotheses for the action of aldosterone.

scholarly journals Role of adenosine on glucagon-induced cAMP in a human cortical collecting duct cell line

1995 ◽  
Vol 47 (5) ◽  
pp. 1310-1318 ◽  
Author(s):  
Dominique Prié ◽  
Gérard Friedlander ◽  
Christiane Coureau ◽  
Alain Vandewalle ◽  
Roland Cassingéna ◽  
...  
Keyword(s):  
Cell Line ◽  
Collecting Duct ◽  
Duct Cell ◽  
Cortical Collecting Duct

Synthesis and secretion of endothelin in a cortical collecting duct cell line

1996 ◽  
Vol 271 (2) ◽  
pp. F330-F339 ◽  
Author(s):  
K. M. Todd-Turla ◽  
X. L. Zhu ◽  
X. Shu ◽  
M. Chen ◽  
T. Yu ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cell Function ◽  
Collecting Duct ◽  
Renal Medulla ◽  
Duct Cell ◽  
Sodium Absorption ◽  
Cortical Collecting Duct ◽  
Collecting Ducts ◽  
Collecting Duct Cells ◽  
High Inhibition

Previous experiments have shown that epithelial cells in the renal medulla produce endothelin-1 (ET-1) and possess ETB receptors. It has been suggested that medullary ET-1 may affect water and sodium absorption along the collecting ducts in an autocrine fashion. To study possible mechanisms responsible for the regulation of medullary ET-1 production, experiments were performed in M-1 cells and mIMCD-K2 cells, cell lines derived from cortical and inner medullary collecting ducts of SV40 transgenic mice, grown to confluence on collagen-coated filter inserts. Both cell lines were found to express ET-1 mRNA and to secrete ET almost exclusively into the basolateral medium as long as the transepithelial resistance was high. Inhibition of transcription with actinomycin D was followed by a decline in both ET mRNA [halftime (t1/2) = 30 min] and ET secretion (t1/2 = approximately 90 min). The addition of arginine vasopressin (AVP, 10(-8) M; 2- or 4-h exposure) or incubation of M-1 cells in hypertonic media (+50 mM NaCl, 4- or 6-h exposure) did not significantly alter ET secretion or ET-1 mRNA expression. In contrast, simultaneously increasing AVP(10(-8) M in the basolateral medium) and tonicity (+50 mM NaCl) for 4 h increased ET secretion (from 28.9 +/- 3.9 to 41.8 +/- 3.8 pg.h-1.mg protein-1; P = 0.029, n = 10) and ET-1 mRNA (control = 2,138 cpm/microliter, log of 3.33 +/- 0.048, n = 4; AVP + NaCl = 3,548.1 cpm/microliter, log of 3.55 +/- 0.09; P = 0.045, n = 5). Exposure of M-1 cells to hypertonic media (+50 mM NaCl or 100 mM mannitol) for 24 h was associated with a marked reduction of ET secretion (-83.9% with NaCl and -78.4% with mannitol; P < 0.0001). This reduction was attenuated, but not prevented, by the presence of AVP in the basolateral medium (-40%). ET-1 mRNA, in contrast, did not change with 24-h exposure to hypertonic media and increased when AVP was present. Results are compatible with the concept that generation of ET by collecting duct cells may contribute in a complex and time-dependent fashion to the paracrine control of collecting duct cell function.

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