1
|
Olde Hanhof CJA, Yousef Yengej FA, Rookmaaker MB, Verhaar MC, van der Wijst J, Hoenderop JG. Modeling Distal Convoluted Tubule (Patho)Physiology: An Overview of Past Developments and an Outlook Toward the Future. Tissue Eng Part C Methods 2021; 27:200-212. [PMID: 33544049 DOI: 10.1089/ten.tec.2020.0345] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The kidneys are essential for maintaining electrolyte homeostasis. Blood electrolyte composition is controlled by active reabsorption and secretion processes in dedicated segments of the kidney tubule. Specifically, the distal convoluted tubule (DCT) and connecting tubule are important for regulating the final excretion of sodium, magnesium, and calcium. Studies unravelling the specific function of these segments have greatly improved our understanding of DCT (patho)physiology. Over the years, experimental models used to study the DCT have changed and the field has advanced from early dissection studies with rats and rabbits to the use of various transgenic mouse models. Developments in dissection techniques and cell culture methods have resulted in immortalized mouse DCT cell lines and made it possible to specifically obtain DCT fragments for ex vivo studies. However, we still do not fully understand the complex (patho)physiology of this segment and there is need for advanced human DCT models. Recently, kidney organoids and tubuloids have emerged as new complex cell models that provide excellent opportunities for physiological studies, disease modeling, drug discovery, and even personalized medicine in the future. This review presents an overview of cell models used to study the DCT and provides an outlook on kidney organoids and tubuloids as model for DCT (patho)physiology. Impact statement This study provides a detailed overview of past and future developments on cell models used to study kidney (patho)physiology and specifically the distal convoluted tubule (DCT) segment. Hereby, we highlight the need for an advanced human cell model of this segment and summarize recent advances in the field of kidney organoids and tubuloids with a focus on DCT properties. The findings reported in this review are significant for future developments toward an advanced human model of the DCT that will help to increase our understanding of DCT (patho)physiology.
Collapse
Affiliation(s)
- Charlotte J A Olde Hanhof
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Fjodor A Yousef Yengej
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences, Utrecht, The Netherlands.,Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Maarten B Rookmaaker
- Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marianne C Verhaar
- Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jenny van der Wijst
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joost G Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| |
Collapse
|
2
|
The sodium/proton exchanger NHA2 regulates blood pressure through a WNK4-NCC dependent pathway in the kidney. Kidney Int 2020; 99:350-363. [PMID: 32956652 DOI: 10.1016/j.kint.2020.08.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 08/13/2020] [Accepted: 08/26/2020] [Indexed: 02/07/2023]
Abstract
NHA2 is a sodium/proton exchanger associated with arterial hypertension in humans, but the role of NHA2 in kidney function and blood pressure homeostasis is currently unknown. Here we show that NHA2 localizes almost exclusively to distal convoluted tubules in the kidney. NHA2 knock-out mice displayed reduced blood pressure, normocalcemic hypocalciuria and an attenuated response to the thiazide diuretic hydrochlorothiazide. Phosphorylation of the thiazide-sensitive sodium/chloride cotransporter NCC and its upstream activating kinase Ste20/SPS1-related proline/alanine rich kinase (SPAK), as well as the abundance of with no lysine kinase 4 (WNK4), were significantly reduced in the kidneys of NHA2 knock-out mice. In vitro experiments recapitulated these findings and revealed increased WNK4 ubiquitylation and enhanced proteasomal WNK4 degradation upon loss of NHA2. The effect of NHA2 on WNK4 stability was dependent from the ubiquitylation pathway protein Kelch-like 3 (KLHL3). More specifically, loss of NHA2 selectively attenuated KLHL3 phosphorylation and blunted protein kinase A- and protein kinase C-mediated decrease of WNK4 degradation. Phenotype analysis of NHA2/NCC double knock-out mice supported the notion that NHA2 affects blood pressure homeostasis by a kidney-specific and NCC-dependent mechanism. Thus, our data show that NHA2 as a critical component of the WNK4-NCC pathway and is a novel regulator of blood pressure homeostasis in the kidney.
Collapse
|
3
|
Sadio M, Tourneur E, Bens M, Goujon JM, Vandewalle A, Chassin C. Cyclosporine A Induces MicroRNAs Controlling Innate Immunity during Renal Bacterial Infection. J Innate Immun 2017; 10:14-29. [PMID: 29069656 DOI: 10.1159/000480248] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 08/13/2017] [Indexed: 12/11/2022] Open
Abstract
Urinary tract infections (UTIs) mainly due to uropathogenic Escherichia coli (UPEC) are one of the most frequent complications in kidney-transplanted patients, causing significant morbidity. However, the mechanisms underlying UTI in renal grafts remain poorly understood. Here, we analysed the effects of the potent immunosuppressive agent cyclosporine A (CsA) on the activation of collecting duct cells that represent a preferential site of adhesion and translocation for UPEC. CsA induced the inhibition of lipopolysaccharide- induced activation of collecting duct cells due to the downregulation of the expression of TLR4 via the microRNA Let-7i. Using an experimental model of ascending UTI, we showed that the pretreatment of mice with CsA prior to infection induced a marked fall in cytokine production by collecting duct cells, neutrophil recruitment, and a dramatic rise of bacterial load, but not in infected TLR4-defective mice kidneys. This effect was also observed in CsA-treated infected kidneys, where the expression of Let-7i was increased. Treatment with a synthetic Let-7i mimic reproduced the effects of CsA. Conversely, pretreatment with an anti-Let-7i antagonised the effects of CsA and rescued the innate immune response of collecting duct cells against UPEC. Thus, the utilisation of an anti-Let-7i during kidney transplantation may protect CsA-treated patients from ascending bacterial infection.
Collapse
Affiliation(s)
- Malick Sadio
- ATIP-Avenir Team Chassin, University Paris Diderot, Sorbonne Paris Cité, CRI, UMR 1149, Inserm, Paris, France
| | | | | | | | | | | |
Collapse
|
4
|
Kortenoeven MLA, Pedersen NB, Rosenbaek LL, Fenton RA. Vasopressin regulation of sodium transport in the distal nephron and collecting duct. Am J Physiol Renal Physiol 2015; 309:F280-99. [DOI: 10.1152/ajprenal.00093.2015] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 05/27/2015] [Indexed: 12/22/2022] Open
Abstract
Arginine vasopressin (AVP) is released from the posterior pituitary gland during states of hyperosmolality or hypovolemia. AVP is a peptide hormone, with antidiuretic and antinatriuretic properties. It allows the kidneys to increase body water retention predominantly by increasing the cell surface expression of aquaporin water channels in the collecting duct alongside increasing the osmotic driving forces for water reabsorption. The antinatriuretic effects of AVP are mediated by the regulation of sodium transport throughout the distal nephron, from the thick ascending limb through to the collecting duct, which in turn partially facilitates osmotic movement of water. In this review, we will discuss the regulatory role of AVP in sodium transport and summarize the effects of AVP on various molecular targets, including the sodium-potassium-chloride cotransporter NKCC2, the thiazide-sensitive sodium-chloride cotransporter NCC, and the epithelial sodium channel ENaC.
Collapse
Affiliation(s)
- M. L. A. Kortenoeven
- Department of Biomedicine and Center for Interactions of Proteins in Epithelial Transport (InterPrET), Aarhus University, Aarhus, Denmark
| | - N. B. Pedersen
- Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark; and
| | - L. L. Rosenbaek
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - R. A. Fenton
- Department of Biomedicine and Center for Interactions of Proteins in Epithelial Transport (InterPrET), Aarhus University, Aarhus, Denmark
| |
Collapse
|
5
|
Labarca M, Nizar JM, Walczak EM, Dong W, Pao AC, Bhalla V. Harvest and primary culture of the murine aldosterone-sensitive distal nephron. Am J Physiol Renal Physiol 2015; 308:F1306-15. [PMID: 25810438 PMCID: PMC4451330 DOI: 10.1152/ajprenal.00668.2014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 03/19/2015] [Indexed: 11/22/2022] Open
Abstract
The aldosterone-sensitive distal nephron (ASDN) exhibits axial heterogeneity in structure and function from the distal convoluted tubule to the medullary collecting duct. Ion and water transport is primarily divided between the cortex and medulla of the ASDN, respectively. Transcellular transport in this segment is highly regulated in health and disease and is integrated across different cell types. We currently lack an inexpensive, high-yield, and tractable technique to harvest and culture cells for the study of gene expression and physiological properties of mouse cortical ASDN. To address this need, we harvested tubules bound to Dolichos biflorus agglutinin lectin-coated magnetic beads from the kidney cortex and characterized these cell preparations. We determined that these cells are enriched for markers of distal convoluted tubule, connecting tubule, and cortical collecting duct, including principal and intercalated cells. In primary culture, these cells develop polarized monolayers with high resistance (1,000-1,500 Ω * cm(2)) and maintain expression and activity of key channels. These cells demonstrate an amiloride-sensitive short-circuit current that can be enhanced with aldosterone and maintain measurable potassium and anion secretion. Our method can be easily adopted to study the biology of the ASDN and to investigate phenotypic differences between wild-type and transgenic mouse models.
Collapse
Affiliation(s)
- Mariana Labarca
- Division of Nephrology, Department of Medicine, Stanford University, Palo Alto, California; and
| | - Jonathan M Nizar
- Division of Nephrology, Department of Medicine, Stanford University, Palo Alto, California; and
| | - Elisabeth M Walczak
- Division of Nephrology, Department of Medicine, Stanford University, Palo Alto, California; and
| | - Wuxing Dong
- Division of Nephrology, Department of Medicine, Stanford University, Palo Alto, California; and
| | - Alan C Pao
- Division of Nephrology, Department of Medicine, Stanford University, Palo Alto, California; and Division of Nephrology, Department of Medicine, Veterans Affairs Palo Alto Healthcare System, Palo Alto, California
| | - Vivek Bhalla
- Division of Nephrology, Department of Medicine, Stanford University, Palo Alto, California; and
| |
Collapse
|
6
|
The function of phosphatidylinositol 5-phosphate 4-kinase γ (PI5P4Kγ) explored using a specific inhibitor that targets the PI5P-binding site. Biochem J 2015; 466:359-67. [PMID: 25495341 PMCID: PMC4687057 DOI: 10.1042/bj20141333] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
NIH-12848 (NCGC00012848-02), a putative phosphatidylinositol 5-phosphate 4-kinase γ (PI5P4Kγ) inhibitor, was explored as a tool for investigating this enigmatic, low activity, lipid kinase. PI5P4K assays in vitro showed that NIH-12848 inhibited PI5P4Kγ with an IC50 of approximately 1 μM but did not inhibit the α and β PI5P4K isoforms at concentrations up to 100 μM. A lack of inhibition of PI5P4Kγ ATPase activity suggested that NIH-12848 does not interact with the enzyme's ATP-binding site and direct exploration of binding using hydrogen–deuterium exchange (HDX)-MS (HDX-MS) revealed the putative PI5P-binding site of PI5P4Kγ to be the likely region of interaction. This was confirmed by a series of mutation experiments which led to the identification of a single PI5P4Kγ amino acid residue that can be mutated to its PI5P4Ks α and β homologue to render PI5P4Kγ resistant NIH-12848 inhibition. NIH-12848 (10 μM) was applied to cultured mouse principal kidney cortical collecting duct (mpkCCD) cells which, we show, express PI5P4Kγ that increases when the cells grow to confluence and polarize. NIH-12848 inhibited the translocation of Na+/K+-ATPase to the plasma membrane that occurs when mpkCCD cells grow to confluence and also prevented reversibly their forming of ‘domes’ on the culture dish. Both these NIH-12848-induced effects were mimicked by specific RNAi knockdown of PI5P4Kγ, but not that of PI5P4Ks α or β. Overall, the data reveal a probable contribution of PI5P4Kγ to the development and maintenance of epithelial cell functional polarity and show that NIH-12848 is a potentially powerful tool for exploring the cell physiology of PI5P4Ks. We have characterised a specific inhibitor of the enzyme Phosphatidylinositol 5-phosphate 4-kinase γ, including establishing where on the enzyme the inhibitor binds, and then applied this inhibitor to a kidney cell line to elucidate the intracellular functions of the enzyme.
Collapse
|
7
|
Wakabayashi M, Mori T, Isobe K, Sohara E, Susa K, Araki Y, Chiga M, Kikuchi E, Nomura N, Mori Y, Matsuo H, Murata T, Nomura S, Asano T, Kawaguchi H, Nonoyama S, Rai T, Sasaki S, Uchida S. Impaired KLHL3-Mediated Ubiquitination of WNK4 Causes Human Hypertension. Cell Rep 2013; 3:858-68. [DOI: 10.1016/j.celrep.2013.02.024] [Citation(s) in RCA: 168] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 01/25/2013] [Accepted: 02/13/2013] [Indexed: 11/28/2022] Open
|
8
|
Amlal H, Xu J, Barone S, Zahedi K, Soleimani M. The chloride channel/transporter Slc26a9 regulates the systemic arterial pressure and renal chloride excretion. J Mol Med (Berl) 2012; 91:561-72. [PMID: 23149824 DOI: 10.1007/s00109-012-0973-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 10/07/2012] [Accepted: 10/16/2012] [Indexed: 01/21/2023]
Abstract
Apical chloride secretory pathways in the kidney medullary collecting duct are thought to play an important role in the modulation of final urine composition and regulation of systemic vascular volume and/or blood pressure. However, the molecular identity of these molecules has largely remained unknown. Here, we demonstrate that Slc26a9, an electrogenic chloride channel/transporter, is localized on the apical membrane of principal cells in the kidney medullary collecting duct and mediates chloride secretion. Mice with the genetic deletion of Slc26a9 show significant reduction in renal chloride excretion when fed a diet high in salt or subjected to water deprivation. Arterial pressure measurements indicated that Slc26a9 knockout (Slc26a9(-/-)) mice are hypertensive under baseline conditions and increase their blood pressure further within 48 h of switching to a high-salt diet. These results suggest that Slc26a9 plays an important role in renal chloride/fluid excretion and arterial pressure regulation. We propose that impaired SLC26A9 activity in humans may interfere with the excretion of excess salt and result in hypertension.
Collapse
Affiliation(s)
- Hassane Amlal
- Research Services, Veterans Affairs Medical Center, Cincinnati, OH, USA
| | | | | | | | | |
Collapse
|
9
|
Markadieu N, San-Cristobal P, Nair AV, Verkaart S, Lenssen E, Tudpor K, van Zeeland F, Loffing J, Bindels RJM, Hoenderop JGJ. A primary culture of distal convoluted tubules expressing functional thiazide-sensitive NaCl transport. Am J Physiol Renal Physiol 2012; 303:F886-92. [PMID: 22759396 DOI: 10.1152/ajprenal.00114.2012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Studying the molecular regulation of the thiazide-sensitive Na(+)-Cl(-) cotransporter (NCC) is important for understanding how the kidney contributes to blood pressure regulation. Until now, a native mammalian cell model to investigate this transporter remained unknown. Our aim here is to establish, for the first time, a primary distal convoluted tubule (DCT) cell culture exhibiting transcellular thiazide-sensitive Na(+) transport. Because parvalbumin (PV) is primarily expressed in the DCT, where it colocalizes with NCC, kidneys from mice expressing enhanced green-fluorescent protein (eGFP) under the PV gene promoter (PV-eGFP-mice) were employed. The Complex Object Parametric Analyzer and Sorter (COPAS) was used to sort fluorescent PV-positive tubules from these kidneys, which were then seeded onto permeable supports. After 6 days, DCT cell monolayers developed transepithelial resistance values of 630 ± 33 Ω·cm(2). The monolayers also established opposing transcellular concentration gradients of Na(+) and K(+). Radioactive (22)Na(+) flux experiments showed a net apical-to-basolateral thiazide-sensitive Na(+) transport across the monolayers. Both hypotonic low-chloride medium and 1 μM angiotensin II increased this (22)Na(+) transport significantly by four times, which could be totally blocked by 100 μM hydrochlorothiazide. Angiotensin II-stimulated (22)Na(+) transport was also inhibited by 1 μM losartan. Furthermore, NCC present in the DCT monolayers was detected by immunoblot and immunocytochemistry studies. In conclusion, a murine primary DCT culture was established which expresses functional thiazide-sensitive Na(+)-Cl(-) transport.
Collapse
Affiliation(s)
- Nicolas Markadieu
- Department of Physiology, Radboud University Nijmegen Medical Centre, The Netherlands
| | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Richardson C, Sakamoto K, de los Heros P, Deak M, Campbell DG, Prescott AR, Alessi DR. Regulation of the NKCC2 ion cotransporter by SPAK-OSR1-dependent and -independent pathways. J Cell Sci 2011; 124:789-800. [PMID: 21321328 DOI: 10.1242/jcs.077230] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ion cotransporters, such as the Na(+)/Cl(-) cotransporter (NCC), control renal salt re-absorption and are regulated by the WNK-signalling pathway, which is over-stimulated in patients suffering from Gordon's hypertension syndrome. Here, we study the regulation of the NKCC2 (SLC12A1) ion cotransporter that contributes towards ~25% of renal salt re-absorption and is inhibited by loop-diuretic hypertensive drugs. We demonstrate that hypotonic low-chloride conditions that activate the WNK1-SPAK and OSR1 pathway promote phosphorylation of NKCC2 isoforms (A, B and F) at five residues (Ser91, Thr95, Thr100, Thr105 and Ser130). We establish that the SPAK and OSR1 kinases activated by WNK interact with an RFQV motif on NKCC2 and directly phosphorylate Thr95, Thr100, Thr105 and, possibly, Ser91. Our data indicate that a SPAK-OSR1-independent kinase, perhaps AMP-activated protein kinase (AMPK), phosphorylates Ser130 and that phosphorylation of Thr105 and Ser130 plays the most important roles in stimulating NKCC2 activity. In contrast with NCC, whose membrane translocation is triggered by SPAK-OSR1 phosphorylation, NKCC2 appears to be constitutively at the membrane. Our findings provide new insights into how NKCC2 is regulated and suggest that inhibitors of SPAK and/or OSR1 for the treatment of hypertension would be therapeutically distinct from thiazide or loop diuretics, as they would suppress the activity of both NCC and NKCC2.
Collapse
Affiliation(s)
- Ciaran Richardson
- MRC Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
| | | | | | | | | | | | | |
Collapse
|
11
|
Mouse cystic fibrosis transmembrane conductance regulator forms cAMP-PKA-regulated apical chloride channels in cortical collecting duct. Proc Natl Acad Sci U S A 2010; 107:6082-7. [PMID: 20231442 DOI: 10.1073/pnas.0902661107] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) is expressed in many segments of the mammalian nephron, where it may interact with and modulate the activity of a variety of apical membrane proteins, including the renal outer medullary potassium (ROMK) K(+) channel. However, the expression of CFTR in apical cell membranes or its function as a Cl(-) channel in native renal epithelia has not been demonstrated. Here, we establish that CFTR forms protein kinase A (PKA)-activated Cl(-) channels in the apical membrane of principal cells from the cortical collecting duct obtained from mice. These Cl(-) channels were observed in cell-attached apical patches of principal cells after stimulation by forskolin/3-isobutyl-1-methylxanthine. Quiescent Cl(-) channels were present in patches excised from untreated tubules because they could be activated after exposure to Mg-ATP and the catalytic subunit of PKA. The single-channel conductance, kinetics, and anion selectivity of these Cl(-) channels were the same as those of recombinant mouse CFTR channels expressed in Xenopus laevis oocytes. The CFTR-specific closed-channel blocker CFTR(inh)-172 abolished apical Cl(-) channel activity in excised patches. Moreover, apical Cl(-) channel activity was completely absent in principal cells from transgenic mice expressing the DeltaF508 CFTR mutation but was present and unaltered in ROMK-null mice. We discuss the physiologic implications of open CFTR Cl(-) channels on salt handling by the collecting duct and on the functional CFTR-ROMK interactions in modulating the metabolic ATP-sensing of ROMK.
Collapse
|
12
|
Nofziger C, Brown KK, Smith CD, Harrington W, Murray D, Bisi J, Ashton TT, Maurio FP, Kalsi K, West TA, Baines D, Blazer-Yost BL. PPARgamma agonists inhibit vasopressin-mediated anion transport in the MDCK-C7 cell line. Am J Physiol Renal Physiol 2009; 297:F55-62. [PMID: 19403648 DOI: 10.1152/ajprenal.00090.2009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
PPARgamma agonists are synthetic ligands for the peroxisome proliferator-activated receptor-gamma (PPARgamma). These agents have insulin-sensitizing properties but can cause fluid retention, thereby limiting their usefulness in patients at risk for cardiovascular disease. The side effect etiology is unknown, but the nature of presentation suggests modulation of renal salt and water homeostasis. In a well-characterized cell culture model of the principal cell type [Madin-Darby canine kidney (MDCK)-C7], PPARgamma agonists inhibit vasopressin-stimulated Cl(-) secretion with agonist dose-response relationships that mirror receptor transactivation profiles. Analyses of the components of the vasopressin-stimulated intracellular signaling pathway indicated no PPARgamma agonist-induced changes in basolateral membrane conductances, intracellular cAMP, protein kinase A, or total cellular adenine nucleotides. The PPARgamma agonist-induced decrease in anion secretion is the result of decreased mRNA of the final effector in the pathway, the apically located cystic fibrosis transmembrane regulator (CFTR). These data showing that CFTR is a target for PPARgamma agonists may provide new insights into the physiology of PPARgamma agonist-induced fluid retention.
Collapse
Affiliation(s)
- Charity Nofziger
- Department of Biology, Indiana University-Purdue University at Indianapolis, Indianapolis, Indiana 46202, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Chassin C, Vimont S, Cluzeaud F, Bens M, Goujon JM, Fernandez B, Hertig A, Rondeau E, Arlet G, Hornef MW, Vandewalle A. TLR4 facilitates translocation of bacteria across renal collecting duct cells. J Am Soc Nephrol 2008; 19:2364-74. [PMID: 18753256 DOI: 10.1681/asn.2007121273] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Uropathogenic Escherichia coli (UPEC) are the most frequent causes of urinary tract infections and pyelonephritis. Renal medullary collecting duct (MCD) cells are the intrarenal site to which UPEC strains prefer to adhere and initiate an inflammatory response, but the ability of UPEC strains to translocate across impermeant MCD cells has not been demonstrated definitively. Here, several UPEC strains adhered to the apical surface and translocated across confluent murine inner MCD cells grown on filters. UPEC strains expressing cytolytic and vacuolating cytotoxins disrupted the integrity of cell layers, whereas noncytolytic UPEC strains passed through the cell layers without altering tight junctions. Apical-to-basal transcellular translocation was dramatically reduced after extinction of Toll-like receptor 4 (TLR4) and the lipid raft marker caveolin-1 by small interfering RNA. Furthermore, disruption of lipid raft integrity by filipin III and methyl-beta-cyclodextrin significantly reduced both the transcellular translocation of UPEC across murine inner MCD cell layers and the stimulation of proinflammatory mediators. Bacterial translocation was also significantly reduced in primary cultures of TLR4-deficient mouse MCD cells compared with MCD cells from wild-type mice. Benzyl alcohol, an anesthetic that enhances membrane fluidity, favored the recruitment of caveolin-1 in lipid rafts and increased the translocation of UPEC across cultured TLR4-deficient MCD cells. These findings demonstrate that the transcellular translocation of UPEC strains across impermeant layers of MCD cells may occur through lipid rafts via a TLR4-facilitated process.
Collapse
Affiliation(s)
- Cécilia Chassin
- INSERM U773, Centre de Recherche Biomédicale Bichat-Beaujon, BP 416, Paris, France
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Bens M, Vandewalle A. Cell models for studying renal physiology. Pflugers Arch 2008; 457:1-15. [DOI: 10.1007/s00424-008-0507-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Accepted: 03/22/2008] [Indexed: 12/24/2022]
|
15
|
Richardson C, Rafiqi FH, Karlsson HKR, Moleleki N, Vandewalle A, Campbell DG, Morrice NA, Alessi DR. Activation of the thiazide-sensitive Na+-Cl- cotransporter by the WNK-regulated kinases SPAK and OSR1. J Cell Sci 2008; 121:675-84. [PMID: 18270262 DOI: 10.1242/jcs.025312] [Citation(s) in RCA: 282] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mutations increasing WNK1 kinase expression in humans cause the pseudohypoaldosteronism type II hypertension syndrome. This condition is treated effectively by thiazide diuretics, which exert their effects by inhibiting the Na+-Cl(-) cotransporter (NCC), suggesting a link between WNK1 and NCC. Here, we demonstrate that the SPAK and OSR1 kinases that are activated by WNK1 phosphorylate human NCC at three conserved residues (Thr46, Thr55 and Thr60). Activation of the WNK1-SPAK/OSR1 signalling pathway by treatment of HEK293 or mpkDCT kidney distal-convoluted-tubule-derived cells with hypotonic low-chloride conditions induced phosphorylation of NCC at residues phosphorylated by SPAK/OSR1. Efficient phosphorylation of NCC was dependent upon a docking interaction between an RFXI motif in NCC and SPAK/OSR1. Mutation of Thr60 to Ala in NCC markedly inhibited phosphorylation of Thr46 and Thr55 as well as NCC activation induced by hypotonic low-chloride treatment of HEK293 cells. Our results establish that the WNK1-SPAK/OSR1 signalling pathway plays a key role in controlling the phosphorylation and activity of NCC. They also suggest a mechanism by which increased WNK1 overexpression could lead to hypertension and that inhibitors of SPAK/OSR1 might be of use in reducing blood pressure by suppressing phosphorylation and hence activity of NCC.
Collapse
Affiliation(s)
- Ciaran Richardson
- MRC Protein Phosphorylation Unit, MSI/WTB complex, University of Dundee, Dow Street, Dundee, DD1 5EH, UK.
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Horisberger JD. Ion Channels in the Apical Membrane: Role of Electrical Coupling on Transepithelial Transport. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007. [DOI: 10.1007/0-387-23250-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
17
|
Chassin C, Bens M, Vandewalle A. Transimmortalized proximal tubule and collecting duct cell lines derived from the kidneys of transgenic mice. Cell Biol Toxicol 2007; 23:257-66. [PMID: 17219250 DOI: 10.1007/s10565-006-0169-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Accepted: 11/29/2006] [Indexed: 01/24/2023]
Abstract
This review summarizes the strategy of cellular immortalization based on the principle of targeted oncogenesis in transgenic mice, used to establish models of transimmortalized renal proximal tubule cells, referred to as PKSV-PCT and PKSV-PR-cells, and collecting duct principal cells, referred to as mpkCCD(cl4) cells. These cell lines have maintained for long-term passages the main biochemical and functional properties of the parental cells from which they were derived. Proximal tubule PKSV-PCT and PKSV-PR cells have been proved to be suitable cell systems for toxicological and pharmacological studies. They also permitted the establishment of a model of multidrug-resistant (MDR) renal epithelial tubule cells, PKSV-PR(col50), which have served for the study of both MDR-dependent extrusion of chemotherapeutic drugs and inappropriate accumulation of weak base anthracyclines in intracellular acidic organelles. The novel collecting duct cell line mpkCCD(cl4), which has maintained the characteristics of tight epithelial cells, in particular Na(+) absorption stimulated by aldosterone, has been extensively used for pharmacological studies related to the regulation of ion transport. These cells have permitted the identification of several aldosterone-induced proteins playing a key role in the regulation of Na(+) absorption mediated by the epithelial Na(+) channel ENaC. Recent studies have also provided evidence that these cell lines represent valuable cell systems for the study of host-pathogen interactions and the analysis of the role of renal tubule epithelial cells in the induction of inflammatory response caused by uropathogens that may lead to severe renal damage.
Collapse
Affiliation(s)
- C Chassin
- INSERM, U773, Centre de Recherche Biomédicale Bichat-Beaujon, Paris, France
| | | | | |
Collapse
|
18
|
Chassin C, Goujon JM, Darche S, du Merle L, Bens M, Cluzeaud F, Werts C, Ogier-Denis E, Le Bouguénec C, Buzoni-Gatel D, Vandewalle A. Renal collecting duct epithelial cells react to pyelonephritis-associated Escherichia coli by activating distinct TLR4-dependent and -independent inflammatory pathways. THE JOURNAL OF IMMUNOLOGY 2006; 177:4773-84. [PMID: 16982918 DOI: 10.4049/jimmunol.177.7.4773] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
TLR4 plays a central role in resistance to pyelonephritis caused by uropathogenic Escherichia coli (UPEC). It has been suggested that renal tubule epithelial cells expressing TLRs may play a key role in inflammatory disorders and in initiating host defenses. In this study we used an experimental mouse model of ascending urinary tract infection to show that UPEC isolates preferentially adhered to the apical surface of medullary collecting duct (MCD) intercalated cells. UPEC-infected C3H/HeJ (Lps(d)) mice carrying an inactivating mutation of tlr4 failed to clear renal bacteria and exhibited a dramatic slump in proinflammatory mediators as compared with infected wild-type C3H/HeOuJ (Lps(n)) mice. However, the level of expression of the leukocyte chemoattractants MIP-2 and TNF-alpha still remained greater in UPEC-infected than in naive C3H/HeJ (Lps(d)) mice. Using primary cultures of microdissected Lps(n) MCDs that expressed TLR4 and its accessory molecules MD2, MyD88, and CD14, we also show that UPECs stimulated both a TLR4-mediated, MyD88-dependent, TIR domain-containing adaptor-inducing IFN-beta-independent pathway and a TLR4-independent pathway, leading to bipolarized secretion of MIP-2. Stimulation by UPECs of the TLR4-mediated pathway in Lps(n) MCDs leads to the activation of NF-kappaB, and MAPK p38, ERK1/2, and JNK. In addition, UPECs stimulated TLR4-independent signaling by activating a TNF receptor-associated factor 2-apoptosis signal-regulatory kinase 1-JNK pathway. These findings demonstrate that epithelial collecting duct cells are actively involved in the initiation of an immune response via several distinct signaling pathways and suggest that intercalated cells play an active role in the recognition of UPECs colonizing the kidneys.
Collapse
Affiliation(s)
- Cécilia Chassin
- INSERM U773, Centre de Recherche Biomédicale Bichat-Beaujon (CRB3), Unité de Formation et de Recherche de Médecine Xavier Bichat, 16 Rue Henri Huchard, F-75870 Paris Cedex 18, France
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Bens M, Chassin C, Vandewalle A. Regulation of NaCl transport in the renal collecting duct: lessons from cultured cells. Pflugers Arch 2006; 453:133-46. [PMID: 16937117 DOI: 10.1007/s00424-006-0123-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2006] [Revised: 06/14/2006] [Accepted: 06/19/2006] [Indexed: 11/29/2022]
Abstract
The fine control of NaCl absorption regulated by hormones takes place in the distal nephron of the kidney. In collecting duct principal cells, the epithelial sodium channel (ENaC) mediates the apical entry of Na(+), which is extruded by the basolateral Na(+),K(+)-ATPase. Simian virus 40-transformed and "transimmortalized" collecting duct cell lines, derived from transgenic mice carrying a constitutive, conditionally, or tissue-specific promoter-regulated large T antigen, have been proven to be valuable tools for studying the mechanisms controlling the cell surface expression and trafficking of ENaC and Na(+),K(+)-ATPase. These cell lines have made it possible to identify sets of aldosterone- and vasopressin-stimulated proteins, and have provided new insights into the concerted mechanism of action of serum- and glucocorticoid-inducible kinase 1 (Sgk1), ubiquitin ligase Nedd4-2 (neural precursor cell-expressed, developmentally down-regulated protein 4-2), and 14-3-3 regulatory proteins in modulating ENaC-mediated Na(+) currents. Epidermal growth factor and induced leucine zipper protein have also been shown to repress and stimulate ENaC-dependent Na(+) absorption, respectively, by activating or repressing the mitogen-activated protein kinase externally regulated kinase(1/2). Overall, these findings have provided evidence suggesting that multiple pathways are involved in regulating NaCl absorption in the distal nephron.
Collapse
Affiliation(s)
- M Bens
- INSERM, U773, Centre de Recherche Biomédicale Bichat-Beaujon, Faculté de Médecine Xavier Bichat, 16 rue Henri Huchard, BP 416, 75870 Paris, France
| | | | | |
Collapse
|
20
|
González-Núñez D, Morales-Ruiz M, Leivas A, Hebert SC, Poch E. In vitro characterization of aldosterone and cAMP effects in mouse distal convoluted tubule cells. Am J Physiol Renal Physiol 2004; 286:F936-44. [PMID: 15075189 DOI: 10.1152/ajprenal.00070.2003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The distal nephron plays a capital role in the fine regulation of sodium reabsorption. Compared with the cortical collecting duct, much less information is available on the hormonal regulation of sodium transporter genes in the distal convoluted tubule (DCT), where the thiazide-sensitive Na+-Cl-cotransporter (NCC) is the major entry pathway for Na+. The purpose of this study was to characterize the in vitro effects of aldosterone (Aldo; 1 μM) and cAMP (8-BrcAMP; 0.5 mM) on mouse DCT (mDCT) by using an immortalized mDCT cell line. Western blot analysis and semiquantitative RT-PCR were performed to analyze the expression of genes involved in sodium transport. The mDCTcell line expressed the 11β-hydroxysteroid dehydrogenase type 2 gene and both the mineralocorticoid and glucocorticoid receptor genes, suggesting Aldo responsiveness. In this sense, we found that mDCT cells expressed the amiloride-sensitive Na+channel (ENaC) and responded to Aldo by upregulating the α-subunit protein. Similarly, α1Na+-K+-ATPase protein was upregulated by Aldo and 8-BrcAMP. In addition, the Aldo intermediate gene sgk1 mRNA was increased in response to both Aldo and 8-BrcAMP, and the transcription factor HNF–3α mRNA was induced by 8-BrcAMP. With respect to NCC regulation, although Aldo induced NCC protein levels in mice in vivo, neither Aldo nor 8-BrcAMP significantly induced the NCC mRNA or protein levels in mDCT cells. These results suggest that in mDCT, Aldo and cAMP modulate some downstream mediators and effectors in vitro but do not influence the expression of NCC in this cell model.
Collapse
Affiliation(s)
- Daniel González-Núñez
- Servicio de Nefrología, and Labrotorio de Hormonología, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Hospital Clinic, Universidad de Barcelona, 08036 Barcelona, Spain
| | | | | | | | | |
Collapse
|
21
|
Abstract
There has been a dramatic recent increase in the understanding of the renal epithelial transport systems with the identification, cloning and characterization of a large number of membrane transport proteins. The aim of this chapter is to integrate this body of knowledge with the understanding of the clinical disorders that accompany gain, loss or dysregulation of function of these transport systems. The specific focus is on the best-defined human clinical syndromes in which there are derangements in potassium (K(+)) homeostasis. The focus is on inherited syndromes, rather than on acquired syndromes due to tubular transport defects, and the therapeutic approaches address chronic derangements of K(+) homeostasis rather than acute interventions directed at life-threatening hyperkalaemia.
Collapse
Affiliation(s)
- David G Warnock
- Division of Nephrology, Departments of Medicine and Physiology, Nephrology Research and Training Center, University of Alabama at Birmingham, 647 THT, 1530 3rd Avenue South, Birmingham, AL 35294-0006, USA.
| |
Collapse
|
22
|
Diepens RJW, den Dekker E, Bens M, Weidema AF, Vandewalle A, Bindels RJM, Hoenderop JGJ. Characterization of a murine renal distal convoluted tubule cell line for the study of transcellular calcium transport. Am J Physiol Renal Physiol 2003; 286:F483-9. [PMID: 14625201 DOI: 10.1152/ajprenal.00231.2003] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To unravel the molecular regulation of renal transcellular Ca(2+) transport, a murine distal convoluted tubule (mpkDCT) cell line derived from distal convoluted tubules (DCT) microdissected from a SV-PK/Tag transgenic mouse was characterized. This cell line originated from DCT only, as mRNA encoding for the DCT marker thiazide-sensitive Na(+)/Cl(-) cotransporter was expressed, whereas mRNA encoding for the connecting tubule and collecting duct marker aquaporin-2 was not detected, as determined by reverse-transcriptase PCR. mpkDCT cells expressed mRNA encoding the Ca(2+) channels TRPV5 and TRPV6 and other key players necessary for transcellular Ca(2+) transport, i.e., calbindin-D(9k), calbindin-D(28k), plasma membrane Ca(2+)-ATPase isoform 1b, and Na(+)/Ca(2+) exchanger 1. Primary cultures of DCT cells exhibited net transcellular Ca(2+) transport of 0.4 +/- 0.1 nmol.h(-1).cm(-2), whereas net transcellular Ca(2+) transport across mpkDCT cells was significantly higher at 2.4 +/- 0.4 nmol.h(-1).cm(-2). Transcellular Ca(2+) transport across mpkDCT cells was completely inhibited by ruthenium red, an inhibitor of TRPV5 and TRPV6, but not by the voltage-operated Ca(2+) channel inhibitors felodipine and verapamil. With the use of patch-clamp analysis, the IC(50) of ruthenium red on Na(+) currents was between the values measured for TRPV5- and TRPV6-expressing HEK 293 cells, suggesting that TRPV5 and/or TRPV6 is possibly active in mpkDCT cells. Forskolin in combination with IBMX, 1,25-dihydroxyvitamin D(3), and 1-deamino-8-d-arginine vasopressin increased transcellular Ca(2+) transport, whereas PMA and parathyroid hormone had no significant effect. In conclusion, the murine mpkDCT cell line provides a unique cell model in which to study the molecular regulation of transcellular Ca(2+) transport in the kidney in vitro.
Collapse
Affiliation(s)
- Robin J W Diepens
- Department of Physiology, Nijmegen Center for Molecualr Life Sciences, University Medical Center, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
23
|
Abstract
The recent knowledge of the renal epithelial transport systems has exploded with the identification, cloning, and characterization of a large number of membrane transport proteins. The fundamental aspects of these transporters are beginning to emerge at the molecular level and are summarized in the accompanying contributions in this volume of the Annual Review of Physiology. The aim of my review is to integrate this body of knowledge with the understanding of the clinical disorders of human mineral homeostasis that accompany gain, loss, or dysregulation of function of these transport systems. The specific focus is on the best defined human clinical syndromes in which there are derangements in K(+) and Mg(2+) homeostasis.
Collapse
Affiliation(s)
- David G Warnock
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, 35294, USA.
| |
Collapse
|
24
|
Bens M, Duong Van Huyen JP, Cluzeaud F, Teulon J, Vandewalle A. CFTR disruption impairs cAMP-dependent Cl(-) secretion in primary cultures of mouse cortical collecting ducts. Am J Physiol Renal Physiol 2001; 281:F434-42. [PMID: 11502593 DOI: 10.1152/ajprenal.2001.281.3.f434] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The role of the cystic fibrosis transmembrane conductance regulator (CFTR) in the renal cortical collecting duct (CCD) has not yet been fully elucidated. Here, we investigated the effects of deamino-8-D-arginine vasopressin (dDAVP) and isoproterenol (ISO) on NaCl transport in primary cultured CCDs microdissected from normal [CFTR(+/+)] and CFTR-knockout [CFTR(-/-)] mice. dDAVP stimulated the benzamyl amiloride (BAm)-sensitive transport of Na(+) assessed by the short-circuit current (I(sc)) method in both CFTR(+/+) and CFTR(-/-) CCDs to a very similar degree. Apical addition of 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB) or glibenclamide partially inhibited the rise in I(sc) induced by dDAVP and ISO in BAm-treated CFTR(+/+) CCDs, whereas dDAVP, ISO, and NPPB did not alter I(sc) in BAm-treated CFTR(-/-) CCDs. dDAVP stimulated the apical-to-basal flux and, to a lesser extent, the basal-to-apical flux of (36)Cl(-) in CFTR(+/+) CCDs. dDAVP also increased the apical-to-basal (36)Cl(-) flux in CFTR(-/-) CCDs but not the basal-to-apical (36)Cl(-) flux. These results demonstrate that CFTR mediates the cAMP-stimulated component of secreted Cl(-) in mouse CCD.
Collapse
Affiliation(s)
- M Bens
- Institut National de la Santé et de la Recherche Médicale, Unité 478, Faculté de Médecine Xavier Bichat, 75870 Paris, France
| | | | | | | | | |
Collapse
|