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Hawksworth GM, Bach PH, Nagelkerke JF, Dekant W, Diezi JE, Harpur E, Lock EA, MacDonald C, Morin JP, Pfaller W, Rutten FA, Ryan MP, Toutain HJ, Trevisan A. Nephrotoxicity Testing In Vitro. Altern Lab Anim 2020. [DOI: 10.1177/026119299502300525] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Gabrielle M. Hawksworth
- Department of Medicine & Therapeutics and Department of Biomedical Sciences, Polwarth Building, University of Aberdeen, Aberdeen AB9 2ZD, UK
| | - Peter H. Bach
- Faculty of Science, University of East London, Romford Road, London E15 4LZ, UK
| | - J. Fred Nagelkerke
- LADCR, Division of Toxicology, Center for Bio-Pharmaceutical Sciences, Leiden University, 2300 RA Leiden, The Netherlands
| | - Wolfgang Dekant
- Universitat Wurzburg, Versbacherstrasse 9, 97074 Wurzburg, Germany
| | - Jacques E. Diezi
- Institut de Pharmacologic et de Toxicologic de l'Universite, rue de Bugnon 27, 1005 Lausanne, Switzerland
| | - Ernest Harpur
- Sanofi-Winthrop Research Centre, Willowburn Avenue, Alnwick, Northumberland NE66 2JH, UK
| | - Edward A. Lock
- ZENECA Central Toxicology Laboratory, Alderley Park, Macclesfield, Cheshire SK10 4TJ, UK
| | - Caroline MacDonald
- Department of Biological Sciences, University of Paisley, High Street, Paisley PA1 2BE, UK
| | - Jean-Paul Morin
- INSERM U295 Uer Medicine Pharmacie, Université de Rouen, 76803 Saint Etienne Rouvray, France
| | - Walter Pfaller
- Institut für Physiologie und Balneologie, Universität Innsbruck, Fritz-Preglstrasse 3, 6010 Innsbruck, Austria
| | - Fons A.J.J.L. Rutten
- TNO Nutrition and Food Research Institute, Division of Toxicology, 3700 AJ Zeist, The Netherlands
| | - Michael P. Ryan
- Department of Pharmacology, University College Dublin, Fosters Avenue, Blackrock, Dublin, Ireland
| | - Hervé J. Toutain
- Rhone-Poulenc Rorer, Centre de Recherche de Vitry, 13 Quai Jules Guisde, 94405 Vitry Cedex, France
| | - Andrea Trevisan
- Instituto di Medicina del Lavoro, Universita di Padova, Via Facciolati 71, 35127 Padova, Italy
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Fernandes-Rosa FL, Hubert EL, Fagart J, Tchitchek N, Gomes D, Jouanno E, Benecke A, Rafestin-Oblin ME, Jeunemaitre X, Antonini SR, Zennaro MC. Mineralocorticoid receptor mutations differentially affect individual gene expression profiles in pseudohypoaldosteronism type 1. J Clin Endocrinol Metab 2011; 96:E519-27. [PMID: 21159846 DOI: 10.1210/jc.2010-1486] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Type 1 pseudohypoaldosteronism (PHA1), a primary form of mineralocorticoid resistance, is due to inactivating mutations of the NR3C2 gene, coding for the mineralocorticoid receptor (MR). OBJECTIVE The objective of the study was to assess whether different NR3C2 mutations have distinct effects on the pattern of MR-dependent transcriptional regulation of aldosterone-regulated genes. DESIGN AND METHODS Four MR mutations affecting residues in the ligand binding domain, identified in families with PHA1, were tested. MR proteins generated by site-directed mutagenesis were analyzed for their binding to aldosterone and were transiently transfected into renal cells to explore the functional effects on the transcriptional activity of the receptors by cis-trans-cotransactivation assays and by measuring the induction of endogenous gene transcription. RESULTS Binding assays showed very low or absent aldosterone binding for mutants MR(877Pro), MR(848Pro), and MR(947stop) and decreased affinity for aldosterone of MR(843Pro). Compared with wild-type MR, the mutations p.Leu843Pro and p.Leu877Pro displayed half-maximal aldosterone-dependent transactivation of reporter genes driven by mouse mammary tumor virus or glucocorticoid response element-2 dependent promoters, whereas MR(848Pro) and MR(947stop) nearly or completely lost transcriptional activity. Although MR(848Pro) and MR(947stop) were also incapable of inducing aldosterone-dependent gene expression of endogenous sgk1, GILZ, NDRG2, and SCNN1A, MR(843Pro) retained complete transcriptional activity on sgk1 and GILZ gene expression, and MR(877Pro) negatively affected the expression of sgk1, NDRG2, and SCNN1A. CONCLUSIONS Our data demonstrate that MR mutations differentially affect individual gene expression in a promoter-dependent manner. Investigation of differential gene expression profiles in PHA1 may allow a better understanding of the molecular substrate of phenotypic variability and to elucidate pathogenic mechanisms underlying the disease.
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Affiliation(s)
- Fábio L Fernandes-Rosa
- Department of Puericulture and Pediatrics, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto 14040-900, Brazil
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van Leeuwen N, Caprio M, Blaya C, Fumeron F, Sartorato P, Ronconi V, Giacchetti G, Mantero F, Fernandes-Rosa FL, Simian C, Peyrard S, Zitman FG, Penninx BW, de Kloet ER, Azizi M, Jeunemaitre X, DeRijk RH, Zennaro MC. The Functional c.-2G>C Variant of the Mineralocorticoid Receptor Modulates Blood Pressure, Renin, and Aldosterone Levels. Hypertension 2010; 56:995-1002. [DOI: 10.1161/hypertensionaha.110.155630] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The mineralocorticoid receptor (MR) is essential in the regulation of volemia and blood pressure. Rare mutations in the MR gene cause type 1 pseudohypoaldosteronism and hypertension. In this study we characterized the common MR polymorphism c.-2G>C (rs2070951) in vitro and tested its influence on parameters related to blood pressure regulation and the renin-angiotensin system. In vitro studies showed that the G allele was associated with decreased MR protein levels and reduced transcriptional activation compared with the C allele. Association studies were performed with several outcome variables in 3 independent cohorts: a mild hypertensive group subjected to a salt-sensitivity test, a healthy normotensive group included in a crossover study to receive both a high and low Na/K diet, and a large cohort (The Netherlands Study of Depression and Anxiety), in which blood pressure was measured. Subjects with the GG genotype had significantly higher plasma renin levels both in the mild hypertensive group and in normal volunteers compared with homozygous C carriers. The GG genotype was also correlated with higher plasma aldosterone levels in healthy subjects. In both the mild hypertensive group and The Netherlands Study of Depression and Anxiety cohort the genotype GG was associated with higher systolic blood pressure in males. In conclusion, the G allele of the common functional genetic polymorphism c.-2G>C in the MR gene associates with increased activation of the renin-angiotensin-aldosterone axis and with increased blood pressure, probably related to decreased MR expression.
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Affiliation(s)
- Nienke van Leeuwen
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - Massimiliano Caprio
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - Carolina Blaya
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - Frédéric Fumeron
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - Paola Sartorato
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - Vanessa Ronconi
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - Gilberta Giacchetti
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - Franco Mantero
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - Fabio L. Fernandes-Rosa
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - Christophe Simian
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - Sévrine Peyrard
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - Frans G. Zitman
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - Brenda W.J.H. Penninx
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - E. Ron de Kloet
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - Michel Azizi
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - Xavier Jeunemaitre
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - Roel H. DeRijk
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
| | - Maria-Christina Zennaro
- From the Division of Medical Pharmacology/Leiden/Amsterdam Center for Drug Research (N.v.L., E.R.d.K., R.H.D.), Leiden University, Leiden, The Netherlands; Centre for Clinical and Basic Research (M.C.), Department of Medical Sciences, Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy; Post-Graduate Program in Medical Sciences: Psychiatry (C.B.), Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil; Institut National de la Santé et de la Recherche
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Viengchareun S, Kamenicky P, Teixeira M, Butlen D, Meduri G, Blanchard-Gutton N, Kurschat C, Lanel A, Martinerie L, Sztal-Mazer S, Blot-Chabaud M, Ferrary E, Cherradi N, Lombès M. Osmotic stress regulates mineralocorticoid receptor expression in a novel aldosterone-sensitive cortical collecting duct cell line. Mol Endocrinol 2009; 23:1948-62. [PMID: 19846540 DOI: 10.1210/me.2009-0095] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Aldosterone effects are mediated by the mineralocorticoid receptor (MR), a transcription factor highly expressed in the distal nephron. Given that MR expression level constitutes a key element controlling hormone responsiveness, there is much interest in elucidating the molecular mechanisms governing MR expression. To investigate whether hyper- or hypotonicity could affect MR abundance, we established by targeted oncogenesis a novel immortalized cortical collecting duct (CCD) cell line and examined the impact of osmotic stress on MR expression. KC3AC1 cells form domes, exhibit a high transepithelial resistance, express 11beta-hydroxysteroid dehydrogenase 2 and functional endogenous MR, which mediates aldosterone-stimulated Na(+) reabsorption through the epithelial sodium channel activation. MR expression is tightly regulated by osmotic stress. Hypertonic conditions induce expression of tonicity-responsive enhancer binding protein, an osmoregulatory transcription factor capable of binding tonicity-responsive enhancer response elements located in MR regulatory sequences. Surprisingly, hypertonicity leads to a severe reduction in MR transcript and protein levels. This is accompanied by a concomitant tonicity-induced expression of Tis11b, a mRNA-destabilizing protein that, by binding to the AU-rich sequences of the 3'-untranslated region of MR mRNA, may favor hypertonicity-dependent degradation of labile MR transcripts. In sharp contrast, hypotonicity causes a strong increase in MR transcript and protein levels. Collectively, we demonstrate for the first time that optimal adaptation of CCD cells to changes in extracellular fluid composition is accompanied by drastic modification in MR abundance via transcriptional and posttranscriptional mechanisms. Osmotic stress-regulated MR expression may represent an important molecular determinant for cell-specific MR action, most notably in renal failure, hypertension, or mineralocorticoid resistance.
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Bengatta S, Arnould C, Letavernier E, Monge M, de Préneuf HM, Werb Z, Ronco P, Lelongt B. MMP9 and SCF protect from apoptosis in acute kidney injury. J Am Soc Nephrol 2009; 20:787-97. [PMID: 19329763 DOI: 10.1681/asn.2008050515] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Apoptosis of tubular epithelial cells is a hallmark of acute kidney injury (AKI), but the cellular events preceding apoptosis in this setting are incompletely understood. Because matrix metalloproteinase 9 (MMP9) degrades matrix components involved in cell survival, we studied the role of MMP9 in AKI. In the mouse model of folic acid-induced AKI, we observed a marked increase of MMP9 activity in the S3 segment of the proximal tubule (S3PT), correlating with the apoptotic phase. MMP9 deficiency increased apoptosis and the severity of renal lesions and substantially delayed recovery of renal function. MMP9-/- mice exhibited significant apoptosis in the S3PT and the intercalated cells of the collecting duct (I-CD), whereas wild-type mice exhibited none in these segments. Stem cell factor (SCF), an MMP9 substrate, was identified in the S3PT, and its receptor, c-Kit, was expressed in both the S3PT and I-CD. MMP9 released the soluble form of SCF (sSCF) from kidney cells in vivo and in vitro. In addition, SCF inhibited apoptosis of tubular cells in vitro, rescued MMP9-/- S3PT and I-CD from apoptosis in vivo, and improved renal function. An ischemia-reperfusion model of AKI produced similar results. In patients with AKI, urinary sSCF increased with acute tubular necrosis but not with prerenal azotemia. In conclusion, these data show that MMP9 protects the S3 segment of the proximal tubule and the I-CD from apoptosis in AKI, most likely by releasing sSCF.
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Mkaddem SB, Werts C, Goujon JM, Bens M, Pedruzzi E, Ogier-Denis E, Vandewalle A. Heat shock protein gp96 interacts with protein phosphatase 5 and controls toll-like receptor 2 (TLR2)-mediated activation of extracellular signal-regulated kinase (ERK) 1/2 in post-hypoxic kidney cells. J Biol Chem 2009; 284:12541-9. [PMID: 19265198 DOI: 10.1074/jbc.m808376200] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ischemia/reperfusion injury (IRI) induces an innate immune response, leading to an inflammatory reaction and tissue damage that have been attributed to engagement of the Toll-like receptor (TLR) 2 and 4. However, the respective roles of TLR2 and/or TLR4 in mediating downstream activation of mitogen-activated protein kinase (MAPK) pathways during IRI have not been fully elucidated. Here we show that extracellular signal-regulated kinase (ERK)1/2 is activated in both intact kidneys and cultured renal tubule epithelial cells (RTECs) from wildtype and Tlr4 knockout mice, but not those from Tlr2 knockout mice subjected to transient ischemia. Geldanamycin (GA), an inhibitor of heat shock protein 90 and reticulum endoplasmic-resident gp96, and gp96 mRNA silencing (siRNA), did not affect ERK1/2 activation in either post-hypoxic wild-type or Tlr4-deficient RTECs, but did restore its activation in post-hypoxic Tlr2-deficient RTECs. Immunoprecipitation studies revealed that gp96 co-immunoprecipitates with the serine-threonine protein phosphatase 5 (PP5), identified as a negative modulator of the mitogen extracellular kinase (MEK)-ERK pathway, in unstressed wild-type and post-hypoxic Tlr2-deficient RTECs. In contrast, PP5 co-immunoprecipitation with gp96 was strikingly reduced in post-hypoxic wild-type RTECs, suggesting that the inactivation of PP5 resulting from the dissociation of PP5 from gp96 allows the activation of ERK1/2 to occur. Inhibition of PP5 by okadaic acid, and Pp5 siRNA also restored TLR2-mediated phosphorylation of ERK1/2, and apoptosis signal-regulating kinase 1 (ASK1)/c-Jun N-terminal kinase (JNK)-mediated apoptosis in post-hypoxic Tlr2-deficient RTECs. These findings indicate that gp96 interacts with PP5 and controls TLR2-mediated induction of ERK1/2 in post-hypoxic renal tubule cells.
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Affiliation(s)
- Sanae Ben Mkaddem
- INSERM U773, Centre de Recherche Biomédicale Bichat-Beaujon CRB3, UFR de Médecine Xavier Bichat, Université Paris 7-Denis Diderot, Site Bichat, BP 416, F-75870 Paris Cedex 18, France
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7
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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]
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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.
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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
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Pascual-Le Tallec L, Simone F, Viengchareun S, Meduri G, Thirman MJ, Lombès M. The Elongation Factor ELL (Eleven-Nineteen Lysine-Rich Leukemia) Is a Selective Coregulator for Steroid Receptor Functions. Mol Endocrinol 2005; 19:1158-69. [PMID: 15650021 DOI: 10.1210/me.2004-0331] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The dynamic and coordinated recruitment of coregulators by steroid receptors is critical for specific gene transcriptional activation. To identify new cofactors of the human (h) mineralocorticoid receptor (MR), its highly specific N-terminal domain was used as bait in a yeast two-hybrid approach. We isolated ELL (eleven-nineteen lysine-rich leukemia), a RNA polymerase II elongation factor which, when fused to MLL (mixed lineage leukemia) contributes to the pathogenesis of acute leukemia. Specific interaction between hMR and ELL was confirmed by glutathione-S-transferase pull-down and coimmunoprecipitation experiments. Transient transfections demonstrated that ELL increased receptor transcriptional potency and hormonal efficacy, indicating that ELL behaves as a bona fide MR coactivator. Of major interest, ELL differentially modulates steroid receptor responses, with striking opposite effects on hMR and glucocorticoid receptor-mediated transactivation, without affecting that of androgen and progesterone receptors. Furthermore, the MLL-ELL fusion protein, as well as several ELL truncated mutants and the ELL L214V mutant, lost their ability to potentiate MR transcriptional activities, suggesting that both the elongation domain and the ELL-associated factor 1 interaction domains are required for ELL to fulfill its selector activity on steroid receptors. This study is the first direct demonstration of a functional interaction between a nuclear receptor and an elongation factor. These results provide further evidence that the selectivity of the mineralo vs. glucocorticoid signaling pathways also occurs at the transcriptional complex level and may have major pathophysiological implications, most notably in leukemogenesis and corticosteroid-induced apoptosis. These findings allow us to propose the concept of "transcriptional selector" for ELL on steroid receptor transcriptional functions.
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Affiliation(s)
- Laurent Pascual-Le Tallec
- Institut National de la Santé et de la Recherche Médicale, Unité 693, Faculté de Médecine Paris-Sud, 63 rue Gabriel Peri, 94276 Le Kremlin Bicetre cedex, France
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Christ M, Wehling M, Kirsch E, Viengchareun S, Zennaro MC, Lombès M. Enhancement of beta-adrenergic cAMP-signaling by the mineralocorticoid receptor. Mol Cell Endocrinol 2005; 231:23-31. [PMID: 15713533 DOI: 10.1016/j.mce.2004.12.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2004] [Revised: 12/09/2004] [Accepted: 12/13/2004] [Indexed: 11/19/2022]
Abstract
We examined the modulation of adrenergic cell signaling by the human mineralocorticoid receptor (hMR) in renal cell lines (RC.SV3) stably transfected with full-length (M cells) or truncated hMR. Isoproterenol time-dependently increased intracellular cAMP formation, which was up to six-fold higher in M cells than in parental RC.SV3 cells. Incubation of cells with aldosterone or spironolactone for 24h neither changed the basal nor the isoproterenol-stimulated cAMP level in both cell lines, while inhibitor studies revealed that those effects are mediated by the beta(2)-adrenergic receptor. Expression of stimulatory G protein alpha was increased and that of G protein receptor coupled kinase 3 (GRK3) was reduced by hMR. Deletion studies of cells stably transfected with truncated hMR indicated that the N-terminal and the DNA binding domains of hMR are essential for enhancement of the catecholamine signal transduction pathway. In conclusion, our findings suggest a novel interplay between cAMP and MR signaling pathways.
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Affiliation(s)
- Michael Christ
- Institute of Clinical Pharmacology, Faculty of Clinical Medicine Mannheim, University of Heidelberg, Theodor Kutzer Ufer 1, D-68135 Mannheim, Germany.
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11
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Plaisier E, Ribes D, Ronco P, Rossert J. Identification of two candidate collecting duct cell-specific cis-acting elements in the Hoxb-7 promoter region. ACTA ACUST UNITED AC 2005; 1727:106-15. [PMID: 15716052 DOI: 10.1016/j.bbaexp.2004.12.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2004] [Revised: 12/06/2004] [Accepted: 12/09/2004] [Indexed: 11/25/2022]
Abstract
HOX genes encode highly conserved transcription factors responsible for developmental patterning and postnatal tissue homeostasis. Previous studies have shown that a 1.4-kb segment of the Hoxb-7 proximal promoter drives renal expression of reporter genes specifically in the ureteric bud and collecting ducts. In this study using stably transfected renal tubule cell lines, we have identified three short cis-acting sequences within this promoter segment that cooperate to induce high-level expression specifically in collecting duct cells. In addition to an inverted CCAAT box (-71/-67) that acts as an ubiquitous enhancer and binds the transcription factor CBF/NF-Y, two different cis-acting sequences, named CDSE-1 and CDSE-2 (for Collecting Duct Specific Element 1 and 2), allow collecting duct cell-specific promoter activation. CDSE-1 (-56/-34) is composed of two E-boxes separated by a 9-bp GC-rich sequence. Only the latter sequence enhances reporter gene expression specifically in collecting duct cells. CDSE-2 (-34/-13) contains sequence bears high homology with a segment of the Pax-2 promoter. CDSE-2 also conveys cell specificity but has no enhancer activity by itself.
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12
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Sartorato P, Cluzeaud F, Fagart J, Viengchareun S, Lombès M, Zennaro MC. New Naturally Occurring Missense Mutations of the Human Mineralocorticoid Receptor Disclose Important Residues Involved in Dynamic Interactions with Deoxyribonucleic Acid, Intracellular Trafficking, and Ligand Binding. Mol Endocrinol 2004; 18:2151-65. [PMID: 15192075 DOI: 10.1210/me.2003-0408] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We have investigated the functional consequences of three naturally occurring amino acid substitutions of the human mineralocorticoid receptor (hMR). These mutations are located in the DNA-binding domain and the ligand-binding domain (LBD) and are associated with autosomal dominant or sporadic type I pseudohypoaldosteronism. All mutant receptors bound specifically to glucocorticoid-responsive elements but presented modified transcriptional properties. The DNA-binding domain mutant G633R, which possesses a normal affinity for a glucocorticoid-responsive element, displayed altered interaction with, and a reduced dissociation rate from, DNA. Its intracellular localization in the absence of hormone was predominantly nuclear in comparison with predominant cytoplasmic location of hMR. Hormone-dependent nuclear cluster formation was comparable to wild-type hMR. These results and the three-dimensional modeling of the interaction of R633 with DNA suggest that altered interaction dynamics with DNA as well as modified intracellular localization may be responsible for submaximal transcriptional potency of hMR. Two LBD mutations, Q776R and L979P, were also investigated. Our data confirm the fundamental role of amino acid Q776 for anchoring the C3 ketone group of steroids in the ligand-binding pocket. Analysis of LBD conformation of mutant P979 demonstrates the relevance of hydrophobic interactions in the extreme C-terminal tail of the hMR for the correct ligand-binding competent state of the receptor. Our data underline the importance of studying naturally occurring mutants to identify crucial residues involved in hMR function.
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Affiliation(s)
- Paola Sartorato
- Institut National de la Santé et de la Recherche Médicale U478, Faculté de Médecine Xavier Bichat, B.P. 416, 16, rue Henri Huchard, 75870 Paris Cedex 18, France
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13
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Volland H, Pradelles P, Taran F, Buscarlet L, Creminon C. Recent developments for SPIE-IA, a new sandwich immunoassay format for very small molecules. J Pharm Biomed Anal 2004; 34:737-52. [PMID: 15019052 DOI: 10.1016/s0731-7085(03)00560-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/17/2003] [Indexed: 11/18/2022]
Abstract
Recent publications describing new elegant approaches to assay small analytes using noncompetitive format were briefly reviewed. Among these methods, we have developed a new protocol, named SPIE-IA, which involves a cross-linking step achieved using chemical hombifunctional reagents, UV irradiation or free radicals. This new method proved to be useful to detect naturally occurring analyte/antibody complexes or to protect the analytes against degradation by peptidases. On the other hand, SPIE-IA could allow to study the adverse biological effects of UV and some aspects of free radical chemistry or to evaluate the antioxidant activity of molecules.
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Affiliation(s)
- Hervé Volland
- CEA, Service de Pharmacologie et d'Immunologie, DRM/DSV, CEA/Saclay, 91191 Gif-sur-Yvette Cedex, France.
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14
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Procino G, Carmosino M, Marin O, Brunati AM, Contri A, Pinna LA, Mannucci R, Nielsen S, Kwon TH, Svelto M, Valenti G. Ser-256 phosphorylation dynamics of Aquaporin 2 during maturation from the ER to the vesicular compartment in renal cells. FASEB J 2003; 17:1886-8. [PMID: 12897058 DOI: 10.1096/fj.02-0870fje] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Aquaporin 2 (AQP2) phosphorylation at Ser-256 by protein kinase A (PKA) is a key signal for vasopressin-stimulated AQP2 insertion into the plasma membrane in renal cells. This study underscores the possible role of phosphorylation at Ser-256 in regulating AQP2 maturation. AQP2-transfected renal CD8 cells were incubated with brefeldin A (BFA) to accumulate newly synthesized AQP2 in the endoplasmic reticulum (ER), and AQP2 flow from ER to the vesicular compartment was analyzed after BFA washout. We found that a) in the ER, AQP2 is weakly phosphorylated; b) the amount of phosphorylated AQP2 (p-AQP2) at Ser-256 increased significantly during transit in the Golgi, even in the presence of the PKA inhibitor H89; and c) AQP2 transport from the Golgi to the vasopressin-regulated vesicular compartment occurred with a concomitant decrease in p-AQP2 at Ser-256. These results support the hypothesis that AQP2 transition in the Golgi apparatus is associated with a PKA-independent increase in AQP2 phosphorylation at Ser-256. Conversely, impaired constitutive phosphorylation in a Golgi-associated compartment occurring in cells expressing mutated S256A-AQP2 or E258K-AQP2 causes phosphorylation-defective AQP2 routing to lysosomes. This result might explain the molecular basis of the dominant form of nephrogenic diabetes insipidus caused by the mutation E258K-AQP2, in which the phenotype is caused by an impaired routing of AQP2.
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Affiliation(s)
- Giuseppe Procino
- Dipartimento di Fisiologia Generale ed Ambientale, University of Bari, 70126 Bari, Italy
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15
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Tallec LPL, Kirsh O, Lecomte MC, Viengchareun S, Zennaro MC, Dejean A, Lombès M. Protein inhibitor of activated signal transducer and activator of transcription 1 interacts with the N-terminal domain of mineralocorticoid receptor and represses its transcriptional activity: implication of small ubiquitin-related modifier 1 modification. Mol Endocrinol 2003; 17:2529-42. [PMID: 14500761 DOI: 10.1210/me.2003-0299] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Molecular mechanisms underlying mineralocorticoid receptor (MR)-mediated gene expression are not fully understood but seem to largely depend upon interactions with specific coregulators. To identify novel human MR (hMR) molecular partners, yeast two-hybrid screenings performed using the N-terminal domain as bait, allowed us to isolate protein inhibitor of activated signal transducer and activator of transcription (PIAS)1 and PIASxbeta, described as SUMO (small ubiquitin-related modifier) E3-ligases. Specific interaction between PIAS1 and hMR was confirmed by glutathione-S-transferase pull-down experiments and N-terminal subdomains responsible for physical contacts were delineated. Transient transfections demonstrated that PIAS1 is a corepressor of aldosterone-activated MR transactivation but has no significant effect on human glucocorticoid receptor transactivation. The agonist or antagonist nature of the bound ligand also determines PIAS1 corepressive action. We provided evidence that PIAS1 conjugated SUMO-1 to hMR both in vitro and in vivo. Deciphering the unique sumoylation pattern of hMR, which possesses five consensus SUMO-1 binding sites, by combinatorial lysine substitutions, revealed a major impact of sumoylation on hMR properties. Using a murine mammary tumor virus promoter, PIAS1 action was independent of sumoylation whereas with glucocorticoid response element promoter, PIAS1 corepressive action depended on hMR sumoylation status. Taken together, our results identify a novel function for PIAS1 which interacts with the N-terminal domain of hMR and represses its ligand-dependent transcriptional activity, at least in part, through SUMO modifications.
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Affiliation(s)
- Laurent Pascual-Le Tallec
- Institut National de la Santé et de la Recherche Médicale, U478, Faculté de Médecine Xavier Bichat, 16 rue Henri Huchard, 75870 Paris cedex 18, France
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16
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Sartorato P, Lapeyraque AL, Armanini D, Kuhnle U, Khaldi Y, Salomon R, Abadie V, Di Battista E, Naselli A, Racine A, Bosio M, Caprio M, Poulet-Young V, Chabrolle JP, Niaudet P, De Gennes C, Lecornec MH, Poisson E, Fusco AM, Loli P, Lombès M, Zennaro MC. Different inactivating mutations of the mineralocorticoid receptor in fourteen families affected by type I pseudohypoaldosteronism. J Clin Endocrinol Metab 2003; 88:2508-17. [PMID: 12788847 DOI: 10.1210/jc.2002-021932] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
We have analyzed the human mineralocorticoid receptor (hMR) gene in 14 families with autosomal dominant or sporadic pseudohypoaldosteronism (PHA1), a rare form of mineralocorticoid resistance characterized by neonatal renal salt wasting and failure to thrive. Six heterozygous mutations were detected. Two frameshift mutations in exon 2 (insT1354, del8bp537) and one nonsense mutation in exon 4 (C2157A, Cys645stop) generate truncated proteins due to premature stop codons. Three missense mutations (G633R, Q776R, L979P) differently affect hMR function. The DNA binding domain mutant R633 exhibits reduced maximal transactivation, although its binding characteristics and ED(50) of transactivation are comparable with wild-type hMR. Ligand binding domain mutants R776 and P979 present reduced or absent aldosterone binding, respectively, which is associated with reduced or absent ligand-dependent transactivation capacity. Finally, P979 possesses a transdominant negative effect on wild-type hMR activity, whereas mutations G633R and Q776R probably result in haploinsufficiency in PHA1 patients. We conclude that hMR mutations are a common feature of autosomal dominant PHA1, being found in 70% of our familial cases. Their absence in some families underscores the importance of an extensive investigation of the hMR gene and the role of precise diagnostic procedures to allow for identification of other genes potentially involved in the disease.
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Affiliation(s)
- Paola Sartorato
- Institut National de la Santé et de la Recherche Médicale, Unité 478, Faculté de Médecine Xavier Bichat, 75018 Paris, France
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17
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Ouali F, Djouadi F, Bastin J. Effects of fatty acids on mitochondrial beta-oxidation enzyme gene expression in renal cell lines. Am J Physiol Renal Physiol 2002; 283:F328-34. [PMID: 12110517 DOI: 10.1152/ajprenal.00324.2001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Regulatory effects of fatty acids on gene expression of medium-chain acyl-CoA dehydrogenase (MCAD), a mitochondrial beta-oxidation enzyme, were investigated in rabbit kidney cell lines derived from proximal tubule (RC.SV1), thick ascending limb of Henle's loop (RC.SV2), or collecting duct (RC.SV3). Exposure to long-chain fatty acids led to significant increases (2-fold) in MCAD mRNA abundance in RC.SV1 and RC.SV2 cells; kinetics and dose-response studies established that maximal MCAD gene stimulation was reached 4 h after addition of 50 microM oleate (C18:1) in the culture medium. These effects of fatty acids were totally abolished in the presence of 1 microg/ml actinomycin D, a transcription inhibitor. Staining of cellular lipids revealed that fatty acid-induced gene stimulation could occur in the absence of cellular fatty acid accumulation. Altogether, these data indicate that small changes in cellular fatty acid flux can have direct short-term effects on fatty acid oxidation enzyme gene expression in renal cells, and this might take part in the regulation of cellular fatty acid homeostasis in response to changes in tubular fluid composition.
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Affiliation(s)
- Fetta Ouali
- Institut National de la Santé et de la Recherche Médicale U319, Université Paris VII, 75015 Paris, France
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18
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Zennaro MC, Souque A, Viengchareun S, Poisson E, Lombès M. A new human MR splice variant is a ligand-independent transactivator modulating corticosteroid action. Mol Endocrinol 2001; 15:1586-98. [PMID: 11518808 DOI: 10.1210/mend.15.9.0689] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Aldosterone effects are mediated by the MR, which possesses the same affinity for mineralocorticoids and glucocorticoids. In addition to the existence of mechanisms regulating intracellular hormone availability, we searched for human MR splice variants involved in tissue-specific corticosteroid function. We have identified a new human MR isoform, hMRDelta5,6, resulting from an alternative splicing event skipping exons 5 and 6 of the human MR gene. hMRDelta5,6 mRNAs are expressed in several human tissues at different levels compared with wild-type human MR, as shown by real time PCR. Introduction of a premature stop codon results in a 75-kDa protein lacking the entire hinge region and ligand binding domain. Interestingly, hMRDelta5,6 is still capable of binding to DNA and acts as a ligand-independent transactivator, with maximal transcriptional induction corresponding to approximately 30-40% of aldosterone-activated wild-type human MR. Coexpression of hMRDelta5,6 with human MR or human GR increases their transactivation potential at high doses of hormone. Finally, hMRDelta5,6 is able to recruit the coactivators, steroid receptor coactivator 1, receptor interacting protein 140, and transcription intermediary factor 1alpha, which enhance its transcriptional activity. Ligand-independent transactivation and enhancement of both wild-type MR and GR activities by hMRDelta5,6 suggests that this new variant might play a role in modulating corticosteroid effects in target tissues.
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Affiliation(s)
- M C Zennaro
- INSERM U 478, Faculté de Médecine Xavier Bichat, 75870 Paris Cedex 18, France.
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19
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Pfaller W, Balls M, Clothier R, Coecke S, Dierickx P, Ekwall B, Hanley BA, Hartung T, Prieto P, Ryan MP, Schmuck G, Sladowski D, Vericat JA, Wendel A, Wolf A, Zimmer J. Novel advanced in vitro methods for long-term toxicity testing: the report and recommendations of ECVAM workshop 45. European Centre for the Validation of Alternative Methods. Altern Lab Anim 2001; 29:393-426. [PMID: 11506637 DOI: 10.1177/026119290102900407] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- W Pfaller
- Institute of Physiology, University of Innsbruck, Austria
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20
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Djouadi F, Bastin J. PPARα Gene Expression in the Developing Rat Kidney: Role of Glucocorticoids. J Am Soc Nephrol 2001; 12:1197-1203. [PMID: 11373342 DOI: 10.1681/asn.v1261197] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Abstract. The α isoform of peroxisome proliferator-activated receptor (PPARα), which is highly expressed in the kidney, can stimulate the expression of genes that are involved in fatty acid catabolism and therefore might be involved in the control of renal fatty acid β-oxidation. PPARα expression and its regulation in the immature kidney are not well documented. This study delineated the developmental pattern of PPARα expression in the rat kidney cortex and the medulla between postnatal days 10 and 30 and investigated the role of glucocorticoids in regulating PPARα expression. In the cortex, PPARα mRNA and protein increased 2- and 1.8-fold, respectively, from 10 to 21 d and then decreased 1.5- and 2.4-fold from 21 to 30 d. In the medulla, PPARα mRNA and protein increased continuously 3.3- and 2.4-fold, respectively. It is shown here that acute treatment by dexamethasone of 10-d-old rats precociously induced a 4- to 6-fold increase in PPARα mRNA and a 1.8-fold increase in protein within 6 h in each part of the kidney. Chronic injection of dexamethasone for 3 d also increased PPARα mRNA 3.8- and 2.2-fold in the cortex and the medulla, respectively, with a 1.5- and 2-fold increase in protein. Furthermore, adrenalectomy prevented the increases in PPARα mRNA and protein in both the cortex and the medulla between postnatal days 16 and 21, and these could be restored by dexamethasone treatment. Finally, with the use of an established renal cell line, it was shown that glucocorticoids stimulate gene expression of PPARα and of medium chain acyl-CoA dehydrogenase (MCAD, a PPARα target gene) 2- to 4-fold and 1.5-fold, respectively, and that addition of fatty acids in the culture media led to a 2.2-fold increase in MCAD mRNA. Altogether, these results demonstrated that glucocorticoids are potent regulators of PPARα development in the immature kidney and that these hormones act in concert with fatty acids to regulate MCAD gene expression in renal cells.
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Affiliation(s)
| | - Jean Bastin
- INSERM U319, Université Paris VII, Paris, France
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21
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Helbert MJ, Dauwe SE, De Broe ME. Flow cytometric immunodissection of the human distal tubule and cortical collecting duct system. Kidney Int 2001; 59:554-64. [PMID: 11168937 DOI: 10.1046/j.1523-1755.2001.059002554.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND In recent years, considerable efforts were drawn to isolate human distal tubule (DT) and collecting duct (CD) cells with more or less success. Here, we present a procedure for isolating human DT cells [thick ascending limb (TAL)/distal convoluted tubule (DCT)] and CD system cells (connecting tubule/initial CD) as separate populations within the same kidney specimen, applying monoclonal antibodies in fluorescence-activated cell sorting (FACS) and culturing them. METHODS We tested antibodies directed against the DT/CD system antigens, epithelial membrane antigen (EMA) and L1-cell adhesion molecule (L1-CAM). Segmental and subsegmental expressions were first assessed by using morphologic and histotopographic criteria, and by comparing sections with adjacent sections stained for expression of well-defined distal subsegment-specific markers. Immunoreactive cells were further characterized by dual immunostaining using cell type-specific markers. As a second step, cells obtained by collagenase digestion of normal renal cortical tissue were flow sorted following labeling with aforementioned antibodies and cultured. RESULTS EMA expression was found on all cells present in the DT and in the CD system. Its expression was most abundant in TAL and from thereon decreased gradually along the course of the DT and CD system. Flow sorting of all EMA-expressing cells resulted in identification/isolation of DT and CD system cells as a heterogeneous mixture. Flow sorting of only the most strongly EMA-positive cells allowed purification of DT cells only, mainly TAL cells as shown by Tamm-Horsfall protein expression on> 80% of sorted cells. L1-CAM was expressed in only the CD system, and sorting of all L1-CAM-positive cells allowed> 95% purification of CD system cells (connecting tubule/cortical CD). Primary cultures of DT and CD system cells rapidly developed into confluent monolayers, and retained antigenic and functional properties inherent to their segments of origin. CONCLUSION Our study presents a procedure for isolating and culturing pure populations of human DT cells and CD system cells as separate populations, using antibodies to the best available markers in FACS.
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Affiliation(s)
- M J Helbert
- Department of Nephrology, University of Antwerp, Belgium
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22
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Calmont A, Reichwald K, Ronco P, Rossert J. Identification of a short cis-acting element in the human vasopressin type 2 receptor gene which confers high-level expression of a reporter gene specifically in collecting duct cells. Mol Endocrinol 2000; 14:1682-95. [PMID: 11043582 DOI: 10.1210/mend.14.10.0540] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
In the kidney, water reabsorption is mainly regulated by the binding of arginine vasopressin to vasopressin type 2 (V2) receptors. These receptors are expressed selectively in principal cells of the collecting ducts. To identify molecular mechanisms responsible for the cell-specific expression of the V2 receptor, we have analyzed the proximal promoter of the corresponding gene. We report the identification of a 33-bp enhancer [collecting duct tissue-specific element 1 (CSE1)] that induced high levels of expression of the luciferase reporter gene in three collecting duct cell lines, but not in other renal cell lines. In gel shift assays, CSE1 bound a DNA-binding protein expressed selectively in collecting duct cell lines, and a 7-bp mutation, which abolished the activity of CSE1 in transient transfection experiments, also abolished the binding of this protein. Furthermore, decoy experiments performed using CSE1 showed that this sequence was involved not only in the expression of a construct containing 4.2 kb of the V2 receptor proximal promoter, but also in the expression of the endogenous V2 receptor gene. CSE1 appears to act mostly by counteracting the inhibitory effects of a strong ubiquitous repressor element that we called CIE1. Collectively, these results identify the first functional collecting duct-specific cis-acting element.
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23
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Valenti G, Procino G, Carmosino M, Frigeri A, Mannucci R, Nicoletti I, Svelto M. The phosphatase inhibitor okadaic acid induces AQP2 translocation independently from AQP2 phosphorylation in renal collecting duct cells. J Cell Sci 2000; 113 ( Pt 11):1985-92. [PMID: 10806109 DOI: 10.1242/jcs.113.11.1985] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phosphorylation by kinases and dephosphorylation by phosphatase markedly affect the biological activity of proteins involved in intracellular signaling. In this study we investigated the effect of the serine/threonine phosphatase inhibitor okadaic acid on water permeability properties and on aquaporin2 (AQP2) translocation in AQP2-transfected renal CD8 cells. In CD8 cells both forskolin alone and okadaic acid alone increased the osmotic water permeability coefficient P(f) by about 4- to 5-fold. In intact cells, in vivo phosphorylation studies revealed that forskolin stimulation resulted in a threefold increase in AQP2 phosphorylation. In contrast, okadaic acid treatment promoted only a 60% increase in AQP2 phosphorylation which was abolished when this treatment was performed in the presence of 1 μM H89, a specific protein kinase A (PKA) inhibitor. Nevertheless, in this latter condition, confocal microscopy analysis revealed that AQP2 translocated and fused to the apical membrane. Okadaic acid-induced AQP2 translocation was dose dependent having its maximal effect at a concentration of 1 μM. In conclusion, our results clearly indicate that okadaic acid exerts a full forskolin-like effect independent from AQP2 phosphorylation. Thus AQP2 phosphorylation is not essential for water channel translocation in renal cells, indicating that different pathways might exist leading to AQP2 apical insertion and increase in P(f).
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Affiliation(s)
- G Valenti
- Dipartimento di Fisiologia Generale ed Ambientale, Universita' degli Studi, Via Amendola 165/A, Italy.
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24
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Vandewalle A, Bens M, Duong Van Huyen JP. Immortalized kidney epithelial cells as tools for hormonally regulated ion transport studies. Curr Opin Nephrol Hypertens 1999; 8:581-7. [PMID: 10541221 DOI: 10.1097/00041552-199909000-00009] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The development of transgenic mice carrying the simian virus-40 large T antigen gene or the temperature-sensitive simian virus-40 large T antigen gene, either alone or placed under the control of the 5'-regulatory regions of tissue-specific or ubiquitous genes, has permitted the production of differentiated, polarized kidney epithelial cells. This review covers the immortalized cell lines issued from the various parts of the renal tubule and, in particular, the recently established collecting duct cell lines that have been used as ex-vivo cell models to analyze the regulation of ion transport processes by hormones.
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Affiliation(s)
- A Vandewalle
- Institut National de la Santé et de la Recherche Médicale, Unité 478, Institut Fédératif de Recherche 02, Faculté de Médecine Xavier Bichat, Paris, France.
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25
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Ingelfinger JR, Jung F, Diamant D, Haveran L, Lee E, Brem A, Tang SS. Rat proximal tubule cell line transformed with origin-defective SV40 DNA: autocrine ANG II feedback. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:F218-27. [PMID: 9950952 DOI: 10.1152/ajprenal.1999.276.2.f218] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The renal proximal tubule (PT) is a major site for a complete tissue renin-angiotensin system (RAS) and produces endogenous angiotensin II (ANG II). The present studies demonstrate autocrine RAS feedback in a line of origin-defective SV40 plasmid transformed immortalized rat PT cells (IRPTC) designated as line 93-p-2-1, which are highly differentiated and express all RAS components. Receptor competition assays and Southern blot following RT-PCR demonstrated that these IRPTC express AT1 and AT2 angiotensin receptor subtypes. Autocrine RAS feedback was examined following exposure to ANG II (10(-8) M), and it was noted that angiotensinogen mRNA increases significantly by 1 h and remains elevated through 24 h. The AT1 blocker losartan prevents this increase. Moreover, ANG II upregulates expression of ANG II receptor mRNA (both AT1 and AT2). Thus the present studies demonstrate positive ANG II feedback with angiotensinogen and ANG II receptors in PTC, suggesting that the main site of such intrarenal feedback in vivo is within PT. ANG II secreted by line 93-p-2-1 is increased by isoproterenol, suggesting beta-adrenergic regulation in IRPTC.
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Affiliation(s)
- J R Ingelfinger
- Pediatric Nephrology Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
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26
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Wu MS, Yu HM, Bens M, Vandewalle A. Cyclosporine, but not FK506 and rapamycin, enhances Na(+)-K(+)-CL- cotransport activity in cultured medullary thick ascending limb cells. Transplant Proc 1999; 31:1180-1. [PMID: 10083527 DOI: 10.1016/s0041-1345(98)01954-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- M S Wu
- Division of Nephrology, Chang-Gang Memorial Hospital, Taipei, Taiwan
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27
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Piedagnel R, Murphy G, Ronco PM, Lelongt B. Matrix metalloproteinase 2 (MMP2) and MMP9 are produced by kidney collecting duct principal cells but are differentially regulated by SV40 large-T, arginine vasopressin, and epidermal growth factor. J Biol Chem 1999; 274:1614-20. [PMID: 9880540 DOI: 10.1074/jbc.274.3.1614] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
We analyzed the expression and regulation of matrix metalloproteinase 2 (MMP2) and MMP9 gelatinases in a rabbit kidney collecting duct principal cell line (RC.SVtsA58) (Prié, D., Ronco, P. M., Baudouin, B., Géniteau-Legendre, M., Antoine, M., Piedagnel, R., Estrade, S., Lelongt, B., Verroust, P. J., Cassingéna, R., and Vandewalle, A. (1991) J. Cell Biol. 113, 951-962) infected with the temperature-sensitive (ts) SV40 strain tsA58. At the permissive temperature (33 degreesC), cells produced only MMP2. Shifting cells to a nonpermissive temperature (39.5 degreesC) induced a marked increase in total gelatinolytic activity due to an increase of MMP2 and an induction of MMP9 synthesis. This effect was attributed to large-T inactivation at 39.5 degreesC because it was abolished by re-infecting the cells with wild-type SV40 strain LP. Run-on experiments showed that negative regulation of MMP2 and MMP9 by large-T was transcriptional and posttranscriptional, respectively. MMP2 and MMP9 were also produced by primary cultures of collecting duct cells. In rabbit kidney, both MMP2 and MMP9 were almost exclusively expressed in collecting duct cells, where an unexpected apical localization was observed. Arginine vasopressin and epidermal growth factor, which exert opposite hydroosmotic effects in the collecting duct, also exhibited contrasted effects on MMP9 synthesis. Epidermal growth factor increased but arginine vasopressin suppressed MMP9 at a posttranscriptional level, whereas MMP2 was not affected. These results suggest a specific physiological role of MMP2 and MMP9 in principal cells of renal collecting duct.
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Affiliation(s)
- R Piedagnel
- INSERM, Unité 489, Hôpital Tenon, 75020 Paris, France.
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28
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Debiec H, Christensen EI, Ronco PM. The cell adhesion molecule L1 is developmentally regulated in the renal epithelium and is involved in kidney branching morphogenesis. J Cell Biol 1998; 143:2067-79. [PMID: 9864376 PMCID: PMC2175226 DOI: 10.1083/jcb.143.7.2067] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We immunopurified a surface antigen specific for the collecting duct (CD) epithelium. Microsequencing of three polypeptides identified the antigen as the neuronal cell adhesion molecule L1, a member of the immunoglobulin superfamily. The kidney isoform showed a deletion of exon 3. L1 was expressed in the mesonephric duct and the metanephros throughout CD development. In the adult CD examined by electron microscopy, L1 was not expressed on intercalated cells but was restricted to CD principal cells and to the papilla tall cells. By contrast, L1 appeared late in the distal portion of the elongating nephron in the mesenchymally derived epithelium and decreased during postnatal development. Immunoblot analysis showed that expression, proteolytic cleavage, and the glycosylation pattern of L1 protein were regulated during renal development. L1 was not detected in epithelia of other organs developing by branching morphogenesis. Addition of anti-L1 antibody to kidney or lung organotypic cultures induced dysmorphogenesis of the ureteric bud epithelium but not of the lung. These results suggest a functional role for L1 in CD development in vitro. We further postulate that L1 may be involved in the guidance of developing distal tubule and in generation and maintenance of specialized cell phenotypes in CD.
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Affiliation(s)
- H Debiec
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 489, Hôpital Tenon, 75020 Paris, France.
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29
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Takacs-Jarrett M, Sweeney WE, Avner ED, Cotton CU. Morphological and functional characterization of a conditionally immortalized collecting tubule cell line. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 275:F802-11. [PMID: 9815138 DOI: 10.1152/ajprenal.1998.275.5.f802] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A conditionally immortalized collecting tubule cell line, mCT1, was derived from the H-2Kb-ts A58 transgenic mouse (ImmortoMouse), which harbors a temperature-sensitive mutant of the SV40 large T antigen oncogene. Cells maintained under permissive conditions [33 degreesC with interferon-gamma (IFN-gamma)] form epithelial monolayers, express large T antigen, and proliferate (>50 passages). The cells retain properties characteristic of the renal collecting tubule (CT) including: vasopressin (VP)-stimulated cAMP accumulation, aquaporin-2 expression, high transepithelial electrical resistance, VP-stimulated ion transport, and amiloride-sensitive sodium absorption. When the cells are transferred to nonpermissive conditions (39 degreesC without IFN-gamma), the steady-state level of large T antigen protein declines (>95% decrease) and cell proliferation is arrested. This conditionally immortalized, murine renal cell line should prove useful for studies of CT physiology and large T antigen biology.
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Affiliation(s)
- M Takacs-Jarrett
- Departments of Pediatrics, and Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106-4948, USA
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30
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Wu MS, Yu HM, Hong JJ, Lai BC, Huang CC, Vandewalle A. Cyclosporine, but not FK 506 and rapamycin, enhances cell proliferation in mouse medullary thick ascending cultured cells. Transplant Proc 1998; 30:3565-6. [PMID: 9838561 DOI: 10.1016/s0041-1345(98)01137-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- M S Wu
- Division of Nephrology, Chang-Gung Memorial Hospital, Taipei, Taiwan
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31
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Valenti G, Procino G, Liebenhoff U, Frigeri A, Benedetti PA, Ahnert-Hilger G, Nürnberg B, Svelto M, Rosenthal W. A heterotrimeric G protein of the Gi family is required for cAMP-triggered trafficking of aquaporin 2 in kidney epithelial cells. J Biol Chem 1998; 273:22627-34. [PMID: 9712891 DOI: 10.1074/jbc.273.35.22627] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Vasopressin is the key regulator of water homeostasis in vertebrates. Central to its antidiuretic action in mammals is the redistribution of the water channel aquaporin 2 (AQP2) from intracellular vesicles to the apical membrane of kidney epithelial cells, an event initiated by an increase in cAMP and activation of protein kinase A. The subsequent steps of the signaling cascade are not known. To identify proteins involved in the AQP2 shuttle we exploited a recently developed cell line (CD8) derived from the rabbit cortical collecting duct and stably transfected with rat AQP2 cDNA. Treatment of CD8 cells with pertussis toxin (PTX) inhibited both the vasopressin-induced increase in water permeability and the redistribution of AQP2 from an intracellular compartment to the apical membrane. ADP-ribosylation studies revealed the presence of at least two major PTX substrates. Correspondingly, two alpha subunits of PTX-sensitive G proteins, Galphai2 and Galphai3, were identified by Western blotting. Introduction of a synthetic peptide corresponding to the C terminus of the Gi3 alpha subunit into permeabilized CD8 cells efficiently inhibited the cAMP-induced AQP2 translocation; a peptide corresponding to the alpha subunits of Gi1/2 was much less potent. Thus a member of the Gi family, most likely Gi3, is involved in the cAMP-triggered targeting of AQP2-bearing vesicles to the apical membrane of kidney epithelial cells.
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Affiliation(s)
- G Valenti
- Dipartimento di Fisiologia Generale e Ambientale, Universitá degli Studi, 70126 Bari, Italy
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32
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Guerra L, Di Sole F, Valenti G, Ronco PM, Perlino E, Casavola V, Reshkin SJ. Polarized distribution of Na+/H+ exchanger isoforms in rabbit collecting duct cells. Kidney Int 1998; 53:1269-77. [PMID: 9573542 DOI: 10.1046/j.1523-1755.1998.00897.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The present study describes two Na+/H+ exchanger (NHE) isoforms in an immortalized rabbit renal cortical collecting tubule cell line (RC.SV3). Na+/H+ exchange activity was assayed using fluorescence measurements of intracellular pH (pHi) in monolayers mounted in a cuvette containing two fluid compartments, making it possible to independently measure Na+/H+ exchange activity on either the apical or basolateral surface. RC.SV3 monolayers express Na+/H+ exchange activities in both the apical and basolateral membrane domains. The two exchangers have half-saturation constants (Km) for external sodium and sensitivities to dimethylamiloride, to HOE-694 and to cimetidine and clonidine consistant with the NHE-1 isoform on the basolateral cell surface and the NHE-2 isoform on the apical surface. Protein kinase A inhibition of basolateral exchanger activity was significantly higher than that of the apical exchanger. Protein kinase C significantly stimulated both exchangers equally. RT-PCR analysis found RNA for only NHE-1 and NHE-2, and immunofluorescence with an antibody against NHE-1 demonstrated a basolateral location for this isoform. The results suggest that RC.SV3 cells have two Na+/H+ exchange activities separated spatially to the two cellular membranes, with the NHE-1 and the NHE-2 isoforms located on the basolateral and the apical membranes, respectively.
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Affiliation(s)
- L Guerra
- Institute of General Physiology, Bari, Italy
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33
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Pfaller W, Gstraunthaler G. Nephrotoxicity testing in vitro--what we know and what we need to know. ENVIRONMENTAL HEALTH PERSPECTIVES 1998; 106 Suppl 2:559-69. [PMID: 9599703 PMCID: PMC1533421 DOI: 10.1289/ehp.98106559] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The kidney is affected by many chemicals. Some of the chemicals may even contribute to end-stage renal disease and thus contribute considerably to health care costs. Because of the large functional reserve of the kidney, which masks signs of dysfunction, early diagnosis of renal disease is often difficult. Although numerous studies aimed at understanding the mechanisms underlying chemicals and drugs that target various renal cell types have delivered enough understanding for a reasonable risk assessment, there is still an urgent need to better understand the mechanisms leading to renal cell injury and organ dysfunction. The increasing use of in vitro techniques using isolated renal cells, nephron fragments, or cell cultures derived from specific renal cell types has improved our insight into the molecular mechanisms involved in nephrotoxicity. A short overview is given on the various in vitro systems currently used to clarify mechanistic aspects leading to sublethal or lethal injury of the functionally most important nephron epithelial cells derived from various species. Whereas freshly isolated cells and nephron fragments appear to represent a sufficient basis to study acute effects (hours) of nephrotoxins, e.g., on cell metabolism, primary cultures of these cells are more appropriate to study long-term effects. In contrast to isolated cells and fragments, however, primary cultures tend to first lose several of their in vivo metabolic properties during culture, and second to have only a limited life span (days to weeks). Moreover, establishing such primary cultures is a time-consuming and laborious procedure. For that reason many studies have been carried out on renal cell lines, which are easy to cultivate in large quantities and which have an unlimited life span. Unfortunately, none of the lines display a state of differentiation comparable to that of freshly isolated cells or their primary cultures. Most often they lack expression of key functions (e.g., gluconeogenesis or organic anion transport) of their in vivo correspondents. Therefore, the use of cell lines for assessment of nephrotoxic mechanisms will be limited to those functions the lines express. Upcoming molecular biology approaches such as the transduction of immortalizing genes into primary cultures and the utilization of cells from transgenic animals may in the near future result in the availability of highly differentiated renal cells with markedly extended life spans and near in vivo characteristics that may facilitate the use of renal cell culture for routine screening of nephrotoxins.
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Affiliation(s)
- W Pfaller
- Institute of Physiology, University of Innsbruck, Austria.
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34
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Garreau I, Chansel D, Vandermeersch S, Fruitier I, Piot JM, Ardaillou R. Hemorphins inhibit angiotensin IV binding and interact with aminopeptidase N. Peptides 1998; 19:1339-48. [PMID: 9809647 DOI: 10.1016/s0196-9781(98)00075-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[125I]-Ang IV binding to rabbit collecting duct cell membranes was inhibited by hemorphins (H), a class of endogenous peptides obtained by hydrolysis of the beta chain of hemoglobin. The most potent competitors were those with a valine in their N-terminal part such as LVV-H7 and VV-H7 (IC50 = 1.3 nM) followed by VV-H8 and K6VV-H7 (5.1 nM). The same H, like Ang IV, interacted with aminopeptidase N (APN) as shown by their inhibitory effect (28-36%) on APN activity. HPLC analysis showed that only H with a N-terminal valine or leucine were hydrolyzed. Since H are detected in the body fluids, they are likely to act as endogenous competitors of Ang IV.
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Affiliation(s)
- I Garreau
- Laboratoire de Génie Protéique, Pôle Sciences et Technologie, La Rochelle, France
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35
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Zannoni S, Boudreau F, Asselin C. Phenotypic analysis of human fetal renal cells transformed by the SV40 large T antigen. In Vitro Cell Dev Biol Anim 1997; 33:598-601. [PMID: 9338139 DOI: 10.1007/s11626-997-0107-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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36
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Blot-Chabaud M, Laplace M, Cluzeaud F, Capurro C, Cassingéna R, Vandewalle A, Farman N, Bonvalet JP. Characteristics of a rat cortical collecting duct cell line that maintains high transepithelial resistance. Kidney Int 1996; 50:367-76. [PMID: 8840262 DOI: 10.1038/ki.1996.325] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
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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Affiliation(s)
- M Blot-Chabaud
- INSERM U246, Institut Fédératif de Recherches Cellules Epithéliales, Faculté de Médecine Xavier Bichat, Paris, France
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37
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Cluzeaud F, Bens M, Wu MS, Li Z, Vicart P, Paulin D, Vandewalle A. Relationships between intermediate filaments and cell-specific functions in renal cell lines derived from transgenic mice harboring the temperature-sensitive T antigen. J Cell Physiol 1996; 167:22-35. [PMID: 8698837 DOI: 10.1002/(sici)1097-4652(199604)167:1<22::aid-jcp3>3.0.co;2-e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Four renal cell lines were derived from glomeruli, proximal, distal, and cortical collecting tubules microdissected from the kidneys of transgenic mice carrying the temperature-sensitive mutant of the simian virus 40 large T antigen under the control of the vimentin promoter. All four cell lines contained large T antigen in their nuclei, grew rapidly, and contained vimentin filaments when grown in serum-enriched medium at the permissive temperature of 33 degrees C. The glomerular cell line formed multiple layers of cells and contained smooth muscle actin and desmin filaments, features of mesangial cells. The three tubule cell lines formed monolayers of polarized cuboid cells separated by tight junctions and having a patchy distribution of cytokeratins K8-K18. A shift from 33 degrees C to the restrictive temperature (39.5 degrees C) stopped cell growth in all cell lines and caused profound changes in the content of intermediate filaments. Vimentin was still present in mesangial-like cells, but the proximal, distal, and collecting tubule cells contained uniform networks of cytokeratins K8-K18 and desmoplakin I and II around the cell peripheries. Potassium transport, mediated by Na+-K+ ATPase pumps and specific cAMP hormonal sensitivities, significantly increased in proximal, distal, and collecting tubule cells when shifted from 33 degrees C to 39.5 degrees C. Thus, the temperature-dependent inactivation of large T antigen, responsible for the arrest of cell growth, did not affect the phenotype of mesangial-like glomerular cells but induced some changes in the expression of intermediate filaments and restored, at least partially, the main parental cell-specific functions in proximal, distal, and collecting tubule cultured cells.
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Affiliation(s)
- F Cluzeaud
- Institut National de la Santé et de la Recherche Médicale, Paris, France
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38
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Kruidering M, van de Water B, Nagelkerke JF. Methods for studying renal toxicity. ARCHIVES OF TOXICOLOGY. SUPPLEMENT. = ARCHIV FUR TOXIKOLOGIE. SUPPLEMENT 1996; 18:173-83. [PMID: 8678793 DOI: 10.1007/978-3-642-61105-6_18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- M Kruidering
- Leiden Amsterdam Center for Drug Research, Sylvius Laboratories, University of Leiden, The Netherlands
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39
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Zoja C, Morigi M, Figliuzzi M, Bruzzi I, Oldroyd S, Benigni A, Ronco P, Remuzzi G. Proximal tubular cell synthesis and secretion of endothelin-1 on challenge with albumin and other proteins. Am J Kidney Dis 1995; 26:934-41. [PMID: 7503068 DOI: 10.1016/0272-6386(95)90058-6] [Citation(s) in RCA: 183] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Abnormal traffic of proteins through the glomerular capillary has an intrinsic renal toxicity possibly linked to the subsequent process of over-reabsorption by proximal tubular cells. We investigated in vitro the effect of different protein concentrations on proximal tubular cell endothelin-1 (ET-1) synthesis. Rabbit proximal tubular RC.SV1 cell line was grown to confluence in serum-free hormonally defined medium. Cells were incubated for 6 and 24 hours with serum-free medium containing bovine serum albumin (BSA, 0.1 to 10 mg/mL). ET-1, a locally released hormone that stimulates cell proliferation and promotes extracellular matrix protein synthesis, was measured in cell supernatant by radioimmunoassay. BSA induced a significant dose-dependent increase in proximal tubular cell ET-1 synthesis. BSA and fatty acid-free BSA stimulated tubular ET-1 synthesis and release to a comparable extent, indicating that the lipid component of the molecule is not involved in the observed phenomenon. Experiments in which tubular cells grown on filters in bicameral systems were incubated with BSA (10 mg/mL) showed that ET-1 release was predominantly basolateral. The stimulatory effect on tubular ET-1 synthesis and release was not specific to albumin but was shared by immunoglobulin (Ig) G and transferrin. Exposure of proximal tubular cells for 6 and 24 hours to both proteins (1 and 10 mg/mL) resulted in a dose-dependent increase in ET-1 synthesis. These data suggest that overexposure of proximal tubular cells to proteins, as it occurs in vivo in proteinuric renal diseases, may promote excessive tubular synthesis of ET-1, which is mostly secreted toward the interstitial compartment.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- C Zoja
- Mario Negri Institute for Pharmacological Research, Bergamo, Italy
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40
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Monteil C, Fillastre JP, Morin JP. Expression and subcellular distribution of phosphoenolpyruvate carboxykinase in primary cultures of rabbit kidney proximal tubule cells: comparative study with renal and hepatic PEPCK in vivo. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1243:437-45. [PMID: 7727519 DOI: 10.1016/0304-4165(94)00171-s] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The behaviour of the phosphoenolpyruvate carboxykinase (PEPCK) in rabbit proximal tubule cells in primary culture was investigated and compared with renal and hepatic PEPCK in vivo. The enzyme activity decreased rapidly in rabbit proximal tubule cells developed in hormonally defined medium supplemented with glucose and insulin. In this condition, the cytosolic form disappears with time. Without glucose and insulin, the subcellular location of PEPCK is similar to the location observed in proximal tubule freshly isolated and in renal cortex, with approx. 50% of mitochondrial form and approx. 50% of cytosolic form. However, the levels of mRNA that encode the cytosolic PEPCK are not detectable in cell cultures, whatever the medium composition. Treatment with dibutyryl cAMP caused a 14-fold induction of PEPCK mRNA in 6 h. This result indicates that the transcription of cytosolic PEPCK can be induced in cell cultures. Lactate or pyruvate additions did not modify the levels of PEPCK mRNA whereas specific activity increased rapidly, suggesting an activation of an inactive form in cell cultures. Moreover, lactate induced increased specific activity of the sole mitochondrial form while pyruvate induced increased specific activities of both mitochondrial and cytosolic form. Thus, subcellular location of PEPCK in rabbit proximal tubule cells appears to be modulated by the available substrate in culture medium. This observation parallels the changes observed in vivo since a modification of subcellular location of this enzyme was seen between fed and fasted rabbit, when subcellular distribution remains similar between fed and starved rats. Moreover, in the fasted liver of rabbit, a decrease of the mitochondrial PEPCK specific activity is seen concomitant with an increase in cytosolic PEPCK activity. These results point out the relative contributions of the cytosolic and mitochondrial PEPCK to rabbit gluconeogenesis.
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Affiliation(s)
- C Monteil
- INSERM U-295-Université de Rouen, Saint Etienne du Rouvray, France
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41
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Briand P, Kahn A, Vandewalle A. Targeted oncogenesis: A powerful method to derive renal cell lines. Kidney Int 1995; 47:388-94. [PMID: 7723228 DOI: 10.1038/ki.1995.51] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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42
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Piédagnel R, Prié D, Cassingéna R, Ronco P, Lelongt B. SV40 large-T oncogene inhibits transcription of perlecan-related proteoglycans but stimulates hyaluronan synthesis in a temperature-sensitive renal-tubule principal cell line. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)32464-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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43
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Prie D, Dussaule JC, Lelongt B, Geniteau-Legendre M, Chatelet F, Cassingena R, Vandewalle A, Ronco PM. Principal cell-specific antigen and hormonal regulatory network in RC.SVtsA58 cell line. THE AMERICAN JOURNAL OF PHYSIOLOGY 1994; 266:C1628-38. [PMID: 8023893 DOI: 10.1152/ajpcell.1994.266.6.c1628] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We used a dual immunomorphological and physiological approach to demonstrate that the RC.SVtsA58 rabbit cortical cell line exhibits features of highly differentiated cortical collecting tubule (CCT) principal cells (PC). First, we raised monoclonal antibodies against RC.SVtsA58 cells and screened their reactivity with the rabbit kidney: three were specific for the basolateral domain of CCT PC and bound to 100% of RC.SVtsA58 cells. Second, we showed that bradykinin, atrial natriuretic peptide, and prostaglandin E2 increased intracellular Ca2+, guanosine 3',5'-cyclic monophosphate, and adenosine 3',5'-cyclic monophosphate (cAMP), respectively. In addition, 10 nM bradykinin inhibited desmopressin-elicited cAMP production by > or = 40%; this effect was suppressed by 10 microM of indomethacin and was reproduced with 1 nM of prostaglandin E2, indicating the conservation of arginine vasopressin-related regulatory loops described in microdissected CCT and freshly isolated cells. However, RC.SVtsA58 cells also express intercalated cell markers even after repeated cloning, which suggests that tsA58, a temperature-sensitive strain of simian virus-40, has transformed a multipotent type of PC in keeping with the cell interconversion hypothesis.
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Affiliation(s)
- D Prie
- Institut National de la Santé et de la Recherche Médicale, Unités 251 and 246, Faculté Xavier Bichat, Paris, France
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44
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Peptide YY receptors in the proximal tubule PKSV-PCT cell line derived from transgenic mice. Relation with cell growth. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(20)80760-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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45
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Vandewalle A, Rafestin-Oblin ME, Hagege J, Géniteau-Legendre M, Cassingéna R, Ronco PM. Phenotypic effects of aldosterone and dexamethasone in a SV40-transformed mammalian cortical ascending limb cell line exhibiting mineralocorticoid receptors. J Cell Physiol 1993; 156:383-94. [PMID: 8393880 DOI: 10.1002/jcp.1041560222] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We have analyzed the functional and morphological effects of corticosteroid hormones in a SV40-transformed rabbit cortical-ascending-limb (CAL) cell line (RC.SV2, Vandewalle et al., 1989) having mineralocorticoid (MR) and glucocorticoid (GR) receptors (Rafestin-Oblin et al., 1993). Both aldosterone and dexamethasone (5 x 10(-8) M) induced a marked increase in (3H)ouabain binding (used to quantify membrane Na(+)-K+ ATPase) detectable as early as 6 hours and maximal at 24 hours (+56-57%) (due to a 1.6-1.8-fold increase in cell membrane binding sites without Kd alteration), and significantly augmented the ouabain-sensitive component of Rb+ influx. Triiodothyronine (T3, 10(-9) M) also stimulated ouabain binding by 21% but was not permissive for steroid action, whereas 5 micrograms/ml insulin had no effect. Both steroid hormones, T3 and insulin induced the formation of domes that was tightly correlated with ouabain binding (r = 0.949) except for insulin. The effects of aldosterone and dexamethasone on cell monolayers and cell ultrastructure were, however, strikingly different as aldosterone induced a marked amplification of basolateral areas with appearance of large intercellular spaces, reminiscent of the changes observed in deoxycorticosterone-treated rats, whereas dexamethasone predominantly influenced cell height. This discrepancy might be due to specific occupancy of MR and GR by aldosterone and dexamethasone, respectively, and/or to nongenomic effects of dexamethasone. We have thus characterized a cell culture model making it possible to analyze the actions of mineralocorticoid and glucocorticoid hormones in the mammalian kidney.
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Lacave R, Bens M, Cartier N, Vallet V, Robine S, Pringault E, Kahn A, Vandewalle A. Functional properties of proximal tubule cell lines derived from transgenic mice harboring L-pyruvate kinase-SV40 (T) antigen hybrid gene. J Cell Sci 1993; 104 ( Pt 3):705-12. [PMID: 8391010 DOI: 10.1242/jcs.104.3.705] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This study describes the functional characterization of two cell lines derived from the proximal convoluted (PKSV-PCT cells) and proximal straight (PKSV-PR) tubules microdissected out from kidneys of transgenic mice harboring the simian virus 40 (SV40) large T and small t antigens placed under the control of the rat L-type pyruvate kinase (L-PK) 5′ regulatory sequence. Both cell lines exhibited cellular cyclic AMP stimulated by parathormone (PTH) and calcitonin (CT) and a sodium-dependent glucose transporter. Uptake of the fluid-phase marker [3H]inulin showed that both cell lines grown on filters exhibited biphasic apical and basolateral endocytic rates. Results from Northern blot analysis indicate that the expression of the T antigen gene (Tag) is dependent on the concentration of D-glucose in the medium and show that the L-PK construct has maintained its capacity for up- or down-regulation by carbohydrates. Replacement of D-glucose by neoglucogenic substrates (lactate, oxaloacetate) blunted the expression of Tag transcripts and induced arrest of cell growth. Compared to cell grown in D-glucose-enriched medium, the hormonal sensitivities to PTH and CT and the sodium-dependent glucose uptake were unchanged whereas quiescent cells exhibited increased hydrolase content. Thus the proximal function has been preserved in these cultured cells derived from tissue-specific targeted oncogenesis in transgenic mice. As the expression of Tag transcripts is controlled by D-glucose, the structural and physiological characteristics of these cell lines can be studied in either quiescent or active growth conditions.
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Affiliation(s)
- R Lacave
- Laboratoire Hospitalo-Universitaire d'Histologie et de Biologie Tumorale, Hôpital Tenon, Paris, France
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Cartier N, Lacave R, Vallet V, Hagege J, Hellio R, Robine S, Pringault E, Cluzeaud F, Briand P, Kahn A. Establishment of renal proximal tubule cell lines by targeted oncogenesis in transgenic mice using the L-pyruvate kinase-SV40 (T) antigen hybrid gene. J Cell Sci 1993; 104 ( Pt 3):695-704. [PMID: 8100235 DOI: 10.1242/jcs.104.3.695] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Targeted oncogenesis allowed us to obtain two cell lines which have been derived from the proximal tubule of kidney from transgenic mice harbouring the simian virus (SV40) large T and small t antigens placed under the control of the 5′ regulatory sequence from the rat L-type pyruvate kinase (L-PK) gene. The cell lines (PKSV-PCT and PKSV-PR cells) were derived from early (PCT) and late (Pars Recta, PR) microdissected proximal tubules grown in D-glucose-enriched medium. In such conditions of culture, both cell lines exhibited L-PK transcripts, a stable expression of SV40-encoded nuclear large T antigen, a prolonged life span but failed to induce tumors when injected sub-cutaneously into athymic (nu-nu) mice. Confluent cells, grown on plastic support or porous filters, were organized as monolayers of polarized cuboid cells with well developed apical microvilli and formed domes. Both cell lines exhibited morphological features of proximal tubule cells with villin located in the apical brush-border and substantial amounts of hydrolase activity. By immunofluorescence studies using specific antibodies, aminopeptidase N appeared restricted to the apical microvillar domain, whereas the H2 histocompatibility antigen was distributed in the cytoplasm and lateral membranes. These results demonstrate that the proximal morphological phenotype has been fully preserved in these cultured cells derived from tissue-specific targeted oncogenesis in transgenic mice.
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Affiliation(s)
- N Cartier
- Institut Cochin de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (INSERM), Faculté Cochin, Paris, France
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Vandewalle A, Vuillemin T, Teulon J, Baudouin B, Wahbe F, Bens M, Cassingéna R, Ronco P. K+ fluxes mediated by Na(+)-K(+)-Cl- cotransport and Na(+)-K(+)-ATPase pumps in renal tubule cell lines transformed by wild-type and temperature-sensitive strains of Simian virus 40. J Cell Physiol 1993; 154:466-77. [PMID: 8382207 DOI: 10.1002/jcp.1041540304] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The relative contributions of Na(+)-K(+)-ATPase pumps and Na(+)-K(+)-Cl- cotransport to total rubidium (Rb+) influx into primary cultures of renal tubule cells (PC.RC) and cells transformed either with the wild-type or a temperature-sensitive mutant of the simian virus 40 (SV40), were measured under various growth conditions. The Na(+)-K(+)-ATPase-mediated component represented 74% and 44-48% of total Rb+ influx into PC.RC and SV40-transformed cells, respectively. Proliferating transformed cells showed substantial ouabain-resistant bumetanide-sensitive (Or-Bs) Rb+ influx (41-45% of total) which indicated the presence of a Na(+)-K(+)-Cl- cotransport. The Or-Bs component of Rb+ influx was greatly reduced when temperature-sensitive transformed renal cells (RC.SVtsA58) grown in Petri dishes or on permeable filters were shifted from the permissive (33 degrees C) to the restrictive temperature (39.5 degrees C) to arrest cell growth. The ouabain-sensitive Rb+ influx mediated by the Na(+)-K(+)-ATPase, the total and amiloride-sensitive Na+ uptakes were not modified following inhibition of cell proliferation. A similar fall in the Or-Bs influx was obtained when renal tubule cells transformed by the wild-type SV40 (RC.SV) were incubated with the K+ channel blocker, tetraethylammonium (TEA) ion, which we had previously shown to arrest cell growth without affecting cell viability (Teulon et al.: J. Cell. Physiol., 151:113-125, 1992). Reinitiation of cell growth by removal of TEA or return to 33 degrees C of the temperature-sensitive cells restored the Or-Bs component of Rb influx. Taken together, these results indicate that the Na(+)-K(+)-Cl- cotransport activity is critically dependent on cell growth conditions.
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Herman P, Cassigena R, Friedlander G, Soler P, Grodet A, Tran Ba Huy P, Amiel C. Middle ear cell line that maintains vectorial electrolyte transport. J Cell Physiol 1993; 154:615-22. [PMID: 8382213 DOI: 10.1002/jcp.1041540321] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The middle ear epithelium plays a major role in keeping the temporal bone cavities fluid-free and air-filled, which is a mandatory condition to allow optimum transmission of the sound vibrations from the tympanic membrane to the inner ear. Previous works have recently established the absorptive function of the middle ear epithelium, using primary cultures derived from Mongolian gerbil (Meriones unguiculatus). Because of the paucity of cells as obtained by enzymatic digestion, we developed a middle ear cell line (MESV) using wild-type SV40 infection of primary culture of Mongolian gerbil's middle ear epithelial cells. Transformation was attested by nuclear expression of SV40 large T antigen, prolonged in vitro passages (presently beyond 50 passages), and tumor-inducing ability when subcutaneously injected in athymic mice. Transport properties were evaluated after the fifteenth passage. MESV cells retained most cardinal properties of the original middle ear epithelial cells: cell polarization was evidenced by the presence of mature junctional complexes that separate the cell membrane in two distinct domains, with apical microvilli at the luminal side, and by vectorial sodium transport responsible for the transepithelial lumen-negative potential difference (-9.3 +/- 0.14 mV in culture conditions (n = 9), -2.1 +/- 0.25 mV after overnight growth factors and serum deprivation). Short-circuit current was, like in primary cultures, mainly related to a sodium transport occurring through amiloride-sensitive apical sodium channels, since apical addition of amiloride (10(-5) M) reduced ISC from 7.0 +/- 1.4 to 0.6 +/- 0.1 microA/cm2 (P < 0.01, n = 6). Cellular cAMP content was increased by isoproterenol and prostaglandin E2 from 40.5 +/- 5.6 to 258.5 +/- 17.3 and 55.6 +/- 6.2 pmol/mg protein per 5 min, respectively (P < 0.05, n = 10). Isoproterenol and prostaglandin E2 increased ISC with very similar maximal effects: isoproterenol (10(-4) M) increased ISC from 5.73 +/- 0.31 to 12.77 +/- 0.39 microA/cm2, while prostaglandin E2 increased ISC from 5.47 +/- 0.21 to 12.87 +/- 0.42 (n = 3). Since amiloride (10(-5) M) abolished this stimulation, this may be related to an increase of the electrogenic sodium transepithelial transport. The MESV cell line could provide an interesting tool as a model of middle ear epithelial cells for the study of pathophysiological modulations of ion transport.
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Affiliation(s)
- P Herman
- Department of Physiology, INSERM U.251, Paris, France
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Rafestin-Oblin ME, Farman N, Cassingena R, Ronco P, Vandewalle A. Mineralocorticoid receptors in SV40-transformed tubule cell lines derived from rabbit kidney. J Steroid Biochem Mol Biol 1993; 44:45-52. [PMID: 8381014 DOI: 10.1016/0960-0760(93)90150-u] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The presence of mineralocorticoid (MR) and glucocorticoid (GR) receptors was investigated in two renal tubular cell lines, derived from primary cultures of isolated rabbit kidney cortical cells infected with the wild-type SV40 virus, which exhibit thick ascending limb (RC.SV2) and collecting tubule (RC.SV3) phenotypes (Vandewalle et al. J. Cell. Physiol. 141, 1989, 203-221). MR and GR were quantified, in cell monolayers and cell cytosolic fractions, with [3H]aldosterone, [3H]dexamethasone and [3H]RU486, an antiglucocorticoid with no affinity for MR. Cytosolic receptors from RC.SV2 and RC.SV3 cells labeled with [3H]aldosterone, [3H]dexamethasone or [3H]RU486 sedimented at approximately 8 S in a 15-40% glycerol gradient. All steroids displaced bound [3H]dexamethasone to the same extent, suggesting that dexamethasone bound to both MR and GR: under the conditions of assay, [3H]aldosterone binds exclusively to MR, and [3H]RU486 to GR. In both RC.SV2 and RC.SV3 cells, [3H]aldosterone bound to one class of high affinity sites (Kd 0.14-0.8 nM; Nmax 8 to 22 fmol/mg protein). In both cell lines, the number of high affinity binding sites for [3H]dexamethasone ranged from 9 to 18 fmol/mg protein with an affinity of 0.5-1.3 nM. Compared to renal cortex, the most striking observation was a marked decrease in [3H]dexamethasone binding in primary cultures and SV40-transformed cells. These results indicate that MR and GR are expressed in two established mammalian kidney tubular cell lines providing new models of cultured renal cells for studies on the physiological effects of corticosteroid hormones.
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Affiliation(s)
- M E Rafestin-Oblin
- Institut National de la Santé et de la Recherche Médicale, INSERM U 246, Paris, France
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