1
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Brengle BM, Lin M, Roth RA, Jones KD, Wagenseil JE, Mecham RP, Halabi CM. A new mouse model of elastin haploinsufficiency highlights the importance of elastin to vascular development and blood pressure regulation. Matrix Biol 2023; 117:1-14. [PMID: 36773748 DOI: 10.1016/j.matbio.2023.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 01/09/2023] [Accepted: 02/07/2023] [Indexed: 02/11/2023]
Abstract
Supravalvular aortic stenosis (SVAS) is an autosomal dominant disease resulting from elastin (ELN) haploinsufficiency. Individuals with SVAS typically develop a thickened arterial media with an increased number of elastic lamellae and smooth muscle cell (SMC) layers and stenosis superior to the aortic valve. A mouse model of SVAS (Eln+/-) was generated that recapitulates many aspects of the human disease, including increased medial SMC layers and elastic lamellae, large artery stiffness, and hypertension. The vascular changes in these mice were thought to be responsible for the hypertension phenotype. However, a renin gene (Ren) duplication in the original 129/Sv genetic background and carried through numerous strain backcrosses raised the possibility of renin-mediated effects on blood pressure. To exclude excess renin activity as a disease modifier, we utilized the Cre-LoxP system to rederive Eln hemizygous mice on a pure C57BL/6 background (Sox2-Cre;Elnf/f). Here we show that Sox2-Cre;Eln+/f mice, with a single Ren1 gene and normal renin levels, phenocopy the original global knockout line. Characteristic traits include an increased number of elastic lamellae and SMC layers, stiff elastic arteries, and systolic hypertension with widened pulse pressure. Importantly, small resistance arteries of Sox2-Cre;Eln+/f mice exhibit a significant change in endothelial cell function and hypercontractility to angiotensin II, findings that point to pathway-specific alterations in resistance arteries that contribute to the hypertensive phenotype. These data confirm that the cardiovascular changes, particularly systolic hypertension, seen in Eln+/- mice are due to Eln hemizygosity rather than Ren duplication.
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Affiliation(s)
- Bridget M Brengle
- Department of Pediatrics, Division of Nephrology, Washington University School of Medicine, St. Louis, MO, USA
| | - Michelle Lin
- Department of Pediatrics, Division of Nephrology, Washington University School of Medicine, St. Louis, MO, USA
| | - Robyn A Roth
- Department of Pediatrics, Division of Nephrology, Washington University School of Medicine, St. Louis, MO, USA
| | - Kara D Jones
- Department of Pediatrics, Division of Nephrology, Washington University School of Medicine, St. Louis, MO, USA
| | - Jessica E Wagenseil
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO, USA
| | - Robert P Mecham
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, U.S.A
| | - Carmen M Halabi
- Department of Pediatrics, Division of Nephrology, Washington University School of Medicine, St. Louis, MO, USA.
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2
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Marshall JL, Noel T, Wang QS, Chen H, Murray E, Subramanian A, Vernon KA, Bazua-Valenti S, Liguori K, Keller K, Stickels RR, McBean B, Heneghan RM, Weins A, Macosko EZ, Chen F, Greka A. High-resolution Slide-seqV2 spatial transcriptomics enables discovery of disease-specific cell neighborhoods and pathways. iScience 2022; 25:104097. [PMID: 35372810 PMCID: PMC8971939 DOI: 10.1016/j.isci.2022.104097] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/15/2022] [Accepted: 03/11/2022] [Indexed: 12/21/2022] Open
Abstract
High-resolution spatial transcriptomics enables mapping of RNA expression directly from intact tissue sections; however, its utility for the elucidation of disease processes and therapeutically actionable pathways remains unexplored. We applied Slide-seqV2 to mouse and human kidneys, in healthy and distinct disease paradigms. First, we established the feasibility of Slide-seqV2 in tissue from nine distinct human kidneys, which revealed a cell neighborhood centered around a population of LYVE1+ macrophages. Second, in a mouse model of diabetic kidney disease, we detected changes in the cellular organization of the spatially restricted kidney filter and blood-flow-regulating apparatus. Third, in a mouse model of a toxic proteinopathy, we identified previously unknown, disease-specific cell neighborhoods centered around macrophages. In a spatially restricted subpopulation of epithelial cells, we discovered perturbations in 77 genes associated with the unfolded protein response. Our studies illustrate and experimentally validate the utility of Slide-seqV2 for the discovery of disease-specific cell neighborhoods.
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Affiliation(s)
- Jamie L. Marshall
- Kidney Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Teia Noel
- Kidney Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Qingbo S. Wang
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Program in Bioinformatics and Integrative Genomics, Harvard Medical School, Boston, MA 02115, USA
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Statistical Genetics, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
| | - Haiqi Chen
- Program in Cell Circuits and Epigenetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Evan Murray
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Ayshwarya Subramanian
- Kidney Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Katherine A. Vernon
- Kidney Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Silvana Bazua-Valenti
- Kidney Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Katie Liguori
- Kidney Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Keith Keller
- Kidney Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Department of Pathology, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Robert R. Stickels
- Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Graduate School of Arts and Sciences, Harvard University, Cambridge, MA 02115, USA
- Division of Medical Science, Harvard University, Boston, MA 02115, USA
| | - Breanna McBean
- Broad Summer Research Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Rowan M. Heneghan
- Kidney Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Astrid Weins
- Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
- Department of Pathology, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Evan Z. Macosko
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Fei Chen
- Program in Cell Circuits and Epigenetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Anna Greka
- Kidney Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
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3
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Emathinger JM, Nelson JW, Gurley SB. Advances in use of mouse models to study the renin-angiotensin system. Mol Cell Endocrinol 2021; 529:111255. [PMID: 33789143 PMCID: PMC9119406 DOI: 10.1016/j.mce.2021.111255] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 01/19/2021] [Accepted: 03/20/2021] [Indexed: 12/28/2022]
Abstract
The renin-angiotensin system (RAS) is a highly complex hormonal cascade that spans multiple organs and cell types to regulate solute and fluid balance along with cardiovascular function. Much of our current understanding of the functions of the RAS has emerged from a series of key studies in genetically-modified animals. Here, we review key findings from ground-breaking transgenic models, spanning decades of research into the RAS, with a focus on their use in studying blood pressure. We review the physiological importance of this regulatory system as evident through the examination of mouse models for several major RAS components: angiotensinogen, renin, ACE, ACE2, and the type 1 A angiotensin receptor. Both whole-animal and cell-specific knockout models have permitted critical RAS functions to be defined and demonstrate how redundancy and multiplicity within the RAS allow for compensatory adjustments to maintain homeostasis. Moreover, these models present exciting opportunities for continued discovery surrounding the role of the RAS in disease pathogenesis and treatment for cardiovascular disease and beyond.
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MESH Headings
- Angiotensin-Converting Enzyme 2/deficiency
- Angiotensin-Converting Enzyme 2/genetics
- Angiotensinogen/deficiency
- Angiotensinogen/genetics
- Animals
- Blood Pressure/genetics
- Cardiovascular Diseases/genetics
- Cardiovascular Diseases/metabolism
- Cardiovascular Diseases/pathology
- Disease Models, Animal
- Gene Expression Regulation
- Humans
- Kidney/cytology
- Kidney/metabolism
- Mice
- Mice, Knockout
- Receptor, Angiotensin, Type 1/deficiency
- Receptor, Angiotensin, Type 1/genetics
- Receptor, Angiotensin, Type 2/deficiency
- Receptor, Angiotensin, Type 2/genetics
- Renin/deficiency
- Renin/genetics
- Renin-Angiotensin System/genetics
- Signal Transduction
- Water-Electrolyte Balance/genetics
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Affiliation(s)
- Jacqueline M Emathinger
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, OR, USA.
| | - Jonathan W Nelson
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, OR, USA.
| | - Susan B Gurley
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, OR, USA.
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4
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Hoy J, Nishimura H, Mehalic T, Yaoita E, Gomez RA, Paxton R, Sequeira-Lopez MLS. Ontogeny of renin gene expression in the chicken, Gallus gallus. Gen Comp Endocrinol 2020; 296:113533. [PMID: 32561435 PMCID: PMC7678913 DOI: 10.1016/j.ygcen.2020.113533] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/02/2020] [Accepted: 06/06/2020] [Indexed: 12/12/2022]
Abstract
Renin or a renin-like enzyme evolved in ancestral vertebrates and is conserved along the vertebrate phylogeny. The ontogenic development of renin, however, is not well understood in nonmammalian vertebrates. We aimed to determine the expression patterns and relative abundance of renin mRNA in pre- and postnatal chickens (Gallus gallus, White Leghorn breed). Embryonic day 13 (E13) embryos show renal tubules, undifferentiated mesenchymal structures, and a small number of developing glomeruli. Maturing glomeruli are seen in post-hatch day 4 (D4) and day 30 (D30) kidneys, indicating that nephrogenic activity still exists in kidneys of 4-week-old chickens. In E13 embryos, renin mRNA measured by quantitative polymerase chain reaction in the adrenal glands is equivalent to the expression in the kidneys, whereas in post-hatch D4 and D30 maturing chicks, renal renin expressions increased 2-fold and 11-fold, respectively. In contrast, relative renin expression in the adrenals became lower than in the kidneys. Furthermore, renin expression is clearly visible by in situ hybridization in the juxtaglomerular (JG) area in D4 and D30 chicks, but not in E13 embryos. The results suggest that in chickens, renin evolved in both renal and extrarenal organs at an early stage of ontogeny and, with maturation, became localized to the JG area. Clear JG structures are not morphologically detectable in E13 embryos, but are visible in 30-day-old chicks, supporting this concept.
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Affiliation(s)
- Jess Hoy
- Child Health Research Center, University of Virginia, Charlottesville, VA, USA
| | - Hiroko Nishimura
- Child Health Research Center, University of Virginia, Charlottesville, VA, USA; Kidney Research Center, Niigata University Graduate Sch. of Med. & Dent. Sci., Niigata, Japan.
| | - Theodore Mehalic
- Child Health Research Center, University of Virginia, Charlottesville, VA, USA
| | - Eishin Yaoita
- Kidney Research Center, Niigata University Graduate Sch. of Med. & Dent. Sci., Niigata, Japan
| | - R Ariel Gomez
- Child Health Research Center, University of Virginia, Charlottesville, VA, USA
| | - Robert Paxton
- Child Health Research Center, University of Virginia, Charlottesville, VA, USA
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5
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Lerman LO, Kurtz TW, Touyz RM, Ellison DH, Chade AR, Crowley SD, Mattson DL, Mullins JJ, Osborn J, Eirin A, Reckelhoff JF, Iadecola C, Coffman TM. Animal Models of Hypertension: A Scientific Statement From the American Heart Association. Hypertension 2019; 73:e87-e120. [PMID: 30866654 DOI: 10.1161/hyp.0000000000000090] [Citation(s) in RCA: 171] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Hypertension is the most common chronic disease in the world, yet the precise cause of elevated blood pressure often cannot be determined. Animal models have been useful for unraveling the pathogenesis of hypertension and for testing novel therapeutic strategies. The utility of animal models for improving the understanding of the pathogenesis, prevention, and treatment of hypertension and its comorbidities depends on their validity for representing human forms of hypertension, including responses to therapy, and on the quality of studies in those models (such as reproducibility and experimental design). Important unmet needs in this field include the development of models that mimic the discrete hypertensive syndromes that now populate the clinic, resolution of ongoing controversies in the pathogenesis of hypertension, and the development of new avenues for preventing and treating hypertension and its complications. Animal models may indeed be useful for addressing these unmet needs.
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6
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Renin Activity in Heart Failure with Reduced Systolic Function-New Insights. Int J Mol Sci 2019; 20:ijms20133182. [PMID: 31261774 PMCID: PMC6651297 DOI: 10.3390/ijms20133182] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 06/26/2019] [Accepted: 06/27/2019] [Indexed: 12/27/2022] Open
Abstract
Regardless of the cause, symptomatic heart failure (HF) with reduced ejection fraction (rEF) is characterized by pathological activation of the renin–angiotensin–aldosterone system (RAAS) with sodium retention and extracellular fluid expansion (edema). Here, we review the role of active renin, a crucial, upstream enzymatic regulator of the RAAS, as a prognostic and diagnostic plasma biomarker of heart failure with reduced ejection fraction (HFrEF) progression; we also discuss its potential as a pharmacological bio-target in HF therapy. Clinical and experimental studies indicate that plasma renin activity is elevated with symptomatic HFrEF with edema in patients, as well as in companion animals and experimental models of HF. Plasma renin activity levels are also reported to be elevated in patients and animals with rEF before the development of symptomatic HF. Modulation of renin activity in experimental HF significantly reduces edema formation and the progression of systolic dysfunction and improves survival. Thus, specific assessment and targeting of elevated renin activity may enhance diagnostic and therapeutic precision to improve outcomes in appropriate patients with HFrEF.
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7
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Buckley C, Nelson RJ, Mullins LJ, Sharp MGF, Fleming S, Kenyon CJ, Semprini S, Steppan D, Peti-Peterdi J, Kurtz A, Christian H, Mullins JJ. Phenotypic dissection of the mouse Ren1d knockout by complementation with human renin. J Biol Chem 2017; 293:1151-1162. [PMID: 29123029 PMCID: PMC5787795 DOI: 10.1074/jbc.ra117.000160] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 11/03/2017] [Indexed: 11/08/2022] Open
Abstract
Normal renin synthesis and secretion is important for the maintenance of juxtaglomerular apparatus architecture. Mice lacking a functional Ren1d gene are devoid of renal juxtaglomerular cell granules and exhibit an altered macula densa morphology. Due to the species-specificity of renin activity, transgenic mice are ideal models for experimentally investigating and manipulating expression patterns of the human renin gene in a native cellular environment without confounding renin–angiotensin system interactions. A 55-kb transgene encompassing the human renin locus was crossed onto the mouse Ren1d-null background, restoring granulation in juxtaglomerular cells. Correct processing of human renin in dense core granules was confirmed by immunogold labeling. After stimulation of the renin–angiotensin system, juxtaglomerular cells contained rhomboid protogranules with paracrystalline contents, dilated rough endoplasmic reticulum, and electron-lucent granular structures. However, complementation of Ren1d−/− mice with human renin was unable to rescue the abnormality seen in macula densa structure. The juxtaglomerular apparatus was still able to respond to tubuloglomerular feedback in isolated perfused juxtaglomerular apparatus preparations, although minor differences in glomerular tuft contractility and macula densa cell calcium handling were observed. This study reveals that the human renin protein is able to complement the mouse Ren1d−/− non-granulated defect and suggests that granulopoiesis requires a structural motif that is conserved between the mouse Ren1d and human renin proteins. It also suggests that the altered macula densa phenotype is related to the activity of the renin-1d enzyme in a local juxtaglomerular renin–angiotensin system.
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Affiliation(s)
- Charlotte Buckley
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom,
| | - Robert J Nelson
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Linda J Mullins
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Matthew G F Sharp
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Stewart Fleming
- the University of Dundee, Ninewells Hospital Medical School, Dundee DD1 9SY, Scotland
| | - Christopher J Kenyon
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Sabrina Semprini
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Dominik Steppan
- the Physiologisches Institut der Universität Regensburg, Regensburg D-93053, Germany
| | - Janos Peti-Peterdi
- the Department of Physiology and Biophysics and Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California 90089, and
| | - Armin Kurtz
- the Physiologisches Institut der Universität Regensburg, Regensburg D-93053, Germany
| | - Helen Christian
- the Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, United Kingdom
| | - John J Mullins
- From the University/BHF Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom,
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9
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Sparks MA, Crowley SD, Gurley SB, Mirotsou M, Coffman TM. Classical Renin-Angiotensin system in kidney physiology. Compr Physiol 2015; 4:1201-28. [PMID: 24944035 DOI: 10.1002/cphy.c130040] [Citation(s) in RCA: 353] [Impact Index Per Article: 39.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The renin-angiotensin system has powerful effects in control of the blood pressure and sodium homeostasis. These actions are coordinated through integrated actions in the kidney, cardiovascular system and the central nervous system. Along with its impact on blood pressure, the renin-angiotensin system also influences a range of processes from inflammation and immune responses to longevity. Here, we review the actions of the "classical" renin-angiotensin system, whereby the substrate protein angiotensinogen is processed in a two-step reaction by renin and angiotensin converting enzyme, resulting in the sequential generation of angiotensin I and angiotensin II, the major biologically active renin-angiotensin system peptide, which exerts its actions via type 1 and type 2 angiotensin receptors. In recent years, several new enzymes, peptides, and receptors related to the renin-angiotensin system have been identified, manifesting a complexity that was previously unappreciated. While the functions of these alternative pathways will be reviewed elsewhere in this journal, our focus here is on the physiological role of components of the "classical" renin-angiotensin system, with an emphasis on new developments and modern concepts.
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Affiliation(s)
- Matthew A Sparks
- Division of Nephrology, Department of Medicine, Duke University Medical Center, Durham, North Carolina
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10
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Schmid J, Oelbe M, Saftig P, Schwake M, Schweda F. Parallel regulation of renin and lysosomal integral membrane protein 2 in renin-producing cells: further evidence for a lysosomal nature of renin secretory vesicles. Pflugers Arch 2013; 465:895-905. [PMID: 23229015 DOI: 10.1007/s00424-012-1192-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 11/23/2012] [Accepted: 11/23/2012] [Indexed: 01/21/2023]
Abstract
The protease renin is the key enzyme in the renin-angiotensin system (RAS) that regulates extracellular volume and blood pressure. Renin is synthesized in renal juxtaglomerular cells (JG cells) as the inactive precursor prorenin. Activation of prorenin by cleavage of the prosegment occurs in renin storage vesicles that have lysosomal properties. To characterize the renin storage vesicles more precisely, the expression and functional relevance of the major lysosomal membrane proteins lysosomal-associated membrane protein 1 (LAMP-1), LAMP-2, and lysosomal integral membrane protein 2 (LIMP-2) were determined in JG cells. Immunostaining experiments revealed strong coexpression of renin with the LIMP-2 (SCARB2), while faint staining of LAMP-1 and LAMP-2 was detected in some JG cells only. Stimulation of the renin system (ACE inhibitor, renal hypoperfusion) resulted in the recruitment of renin-producing cells in the afferent arterioles and parallel upregulation of LIMP-2, but not LAMP-1 or LAMP-2. Despite the coregulation of renin and LIMP-2, LIMP-2-deficient mice had normal renal renin mRNA levels, renal renin and prorenin contents, and plasma renin and prorenin concentrations under control conditions and in response to stimulation with a low salt diet (with or without angiotensin-converting enzyme (ACE) inhibition). No differences in the size or number of renin vesicles were detected using electron microscopy. Acute stimulation of renin release by isoproterenol exerted similar responses in both genotypes in vivo and in isolated perfused kidneys. Renin and the major lysosomal protein LIMP-2 are colocalized and coregulated in renal JG cells, further corroborating the lysosomal nature of renin storage vesicles. LIMP-2 does not appear to play an obvious role in the regulation of renin synthesis or release.
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Affiliation(s)
- Johannes Schmid
- Institut für Physiologie, Universität Regensburg, 93040, Regensburg, Germany
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11
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Rossier BC, Staub O, Hummler E. Genetic dissection of sodium and potassium transport along the aldosterone-sensitive distal nephron: importance in the control of blood pressure and hypertension. FEBS Lett 2013; 587:1929-41. [PMID: 23684652 DOI: 10.1016/j.febslet.2013.05.013] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Accepted: 05/06/2013] [Indexed: 10/26/2022]
Abstract
In this review, we discuss genetic evidence supporting Guyton's hypothesis stating that blood pressure control is critically depending on fluid handling by the kidney. The review is focused on the genetic dissection of sodium and potassium transport in the distal nephron and the collecting duct that are the most important sites for the control of sodium and potassium balance by aldosterone and angiotensin II. Thanks to the study of Mendelian forms of hypertension and their corresponding transgenic mouse models, three main classes of diuretic receptors (furosemide, thiazide, amiloride) and the main components of the aldosterone- and angiotensin-dependent signaling pathways were molecularly identified over the past 20 years. This will allow to design rational strategies for the treatment of hypertension and for the development of the next generation of diuretics.
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12
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Steppan D, Zügner A, Rachel R, Kurtz A. Structural analysis suggests that renin is released by compound exocytosis. Kidney Int 2013; 83:233-41. [DOI: 10.1038/ki.2012.392] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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13
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Abstract
The aspartyl protease renin is the rate limiting activity of the renin-angiotensin-aldosterone system (RAAS). Renin is synthesized as an enzymatically inactive proenzyme which is constitutively secreted from several tissues. Only renin-expressing cells in the kidney are capable of generating active renin from prorenin, which is stored in prominent vesicles and which is released into the circulation upon demand. The acute release of renin is controlled by cyclic adenosine monophosphate (cAMP) and by calcium signaling pathways, which in turn are activated by a number of systemic and local factors. Longer lasting challenges of renin secretion lead to changes in the number of renin-producing cells, which occur by a metaplastic transformation of renin cell precursors such as preglomerular vascular smooth muscle or extraglomerular mesangial cells. This review aims to briefly address the state of knowledge of these various aspects of renin synthesis and secretion and attempts to relate them to the in vivo situation, in particular in men.
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14
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Peters J. Local renin-angiotensin systems in the adrenal gland. Peptides 2012; 34:427-32. [PMID: 22391260 DOI: 10.1016/j.peptides.2012.01.023] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 01/28/2012] [Accepted: 01/28/2012] [Indexed: 10/28/2022]
Abstract
In the adrenal gland all components of the renin-angiotensin system (RAS) are expressed in both the adrenal cortex and the adrenal medulla. In this review evidence shall be presented that a local secretory RAS exists in the adrenal cortex that stimulates aldosterone production and serves as an amplification system for circulating angiotensin (ANG) II. The regulation of the secretory adrenal RAS clearly differs from the regulation of the circulatory RAS in terms of renin expression as well as of renin secretion. For example under potassium load the activity of the renal and circulatory RAS is suppressed whereas the activity of the adrenal RAS is stimulated. Thus the activity of the adrenal RAS but not of the circulating RAS correlates well with the regulation of aldosterone production by potassium. The present review also summarizes the knowledge about the expression and functions of an additional renin transcript that has recently been discovered. This transcript encodes for a non-secretory cytosolic renin isoform. The cytosolic renin may be a basis for the existence of an intracellular renin system in the adrenal gland that has long been proposed. The present state of knowledge shall be discussed indicating that such an intracellular system modulates cell survival and cell death such as apoptosis and necrosis or cell functions such as aldosterone production.
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Affiliation(s)
- Jörg Peters
- Institute of Physiology, University of Greifswald, Germany.
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15
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Schnermann J, Briggs JP. Synthesis and secretion of renin in mice with induced genetic mutations. Kidney Int 2012; 81:529-38. [PMID: 22258323 DOI: 10.1038/ki.2011.451] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The juxtaglomerular (JG) cell product renin is rate limiting in the generation of the bioactive octapeptide angiotensin II. Rates of synthesis and secretion of the aspartyl protease renin by JG cells are controlled by multiple afferent and efferent pathways originating in the CNS, cardiovascular system, and kidneys, and making critical contributions to the maintenance of extracellular fluid volume and arterial blood pressure. Since both excesses and deficits of angiotensin II have deleterious effects, it is not surprising that control of renin is secured by a complex system of feedforward and feedback relationships. Mice with genetic alterations have contributed to a better understanding of the networks controlling renin synthesis and secretion. Essential input for the setting of basal renin generation rates is provided by β-adrenergic receptors acting through cyclic adenosine monophosphate, the primary intracellular activation mechanism for renin mRNA generation. Other major control mechanisms include COX-2 and nNOS affecting renin through PGE2, PGI2, and nitric oxide. Angiotensin II provides strong negative feedback inhibition of renin synthesis, largely an indirect effect mediated by baroreceptor and macula densa inputs. Adenosine appears to be a dominant factor in the inhibitory arms of the baroreceptor and macula densa mechanisms. Targeted gene mutations have also shed light on a number of novel aspects related to renin processing and the regulation of renin synthesis and secretion.
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Affiliation(s)
- Jurgen Schnermann
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
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16
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Moreno C, Hoffman M, Stodola TJ, Didier DN, Lazar J, Geurts AM, North PE, Jacob HJ, Greene AS. Creation and characterization of a renin knockout rat. Hypertension 2011; 57:614-9. [PMID: 21242461 PMCID: PMC3513323 DOI: 10.1161/hypertensionaha.110.163840] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Accepted: 12/15/2010] [Indexed: 12/14/2022]
Abstract
The renin-angiotensin system plays an important role in the control of blood pressure (BP) and renal function. To illuminate the importance of renin in the context of a disease background in vivo, we used zinc-finger nucleases (ZFNs) designed to target the renin gene and create a renin knockout in the SS/JrHsdMcwi (SS) rat. ZFN against renin caused a 10-bp deletion in exon 5, resulting in a frameshift mutation. Plasma renin activity was undetectable in the Ren-/- rat, and renin protein was absent from the juxtaglomerular cells in the kidney. Body weight was lower in the Ren-/- rats (than in the Ren+/- or wild-type littermates), and conscious BP on low-salt diet (0.4% NaCl) was 58 ± 2 mm Hg in the Ren-/- male rats versus 117 mm Hg in the Ren+/- littermates, a reduction of almost 50 mm Hg. Blood urea nitrogen (BUN) and plasma creatinine levels were elevated in the Ren-/- strain (BUN 112 ± 7 versus 23 ± 2 mg/dL and creatinine 0.53 ± 0.02 versus 0.26 ± 0.02 mg/dL), and kidney morphology was abnormal with a rudimentary inner renal medulla, cortical interstitial fibrosis, thickening of arterial walls, and abnormally shaped glomeruli. The development of the first rat knockout in the renin-angiotensin system demonstrates the efficacy of the ZFN technology for creating knockout rats for cardiovascular disease on any genetic background and emphasizes the role of renin in BP regulation and kidney function even in the low-renin SS rat.
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Affiliation(s)
- Carol Moreno
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
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17
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Castrop H, Höcherl K, Kurtz A, Schweda F, Todorov V, Wagner C. Physiology of Kidney Renin. Physiol Rev 2010; 90:607-73. [PMID: 20393195 DOI: 10.1152/physrev.00011.2009] [Citation(s) in RCA: 189] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The protease renin is the key enzyme of the renin-angiotensin-aldosterone cascade, which is relevant under both physiological and pathophysiological settings. The kidney is the only organ capable of releasing enzymatically active renin. Although the characteristic juxtaglomerular position is the best known site of renin generation, renin-producing cells in the kidney can vary in number and localization. (Pro)renin gene transcription in these cells is controlled by a number of transcription factors, among which CREB is the best characterized. Pro-renin is stored in vesicles, activated to renin, and then released upon demand. The release of renin is under the control of the cAMP (stimulatory) and Ca2+(inhibitory) signaling pathways. Meanwhile, a great number of intrarenally generated or systemically acting factors have been identified that control the renin secretion directly at the level of renin-producing cells, by activating either of the signaling pathways mentioned above. The broad spectrum of biological actions of (pro)renin is mediated by receptors for (pro)renin, angiotensin II and angiotensin-( 1 – 7 ).
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Affiliation(s)
- Hayo Castrop
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Klaus Höcherl
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Armin Kurtz
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Frank Schweda
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Vladimir Todorov
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Charlotte Wagner
- Institute of Physiology, University of Regensburg, Regensburg, Germany
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18
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Gross KW, Gomez RA, Sigmund CD. Twists and turns in the search for the elusive renin processing enzyme: focus on "Cathepsin B is not the processing enzyme for mouse prorenin". Am J Physiol Regul Integr Comp Physiol 2010; 298:R1209-11. [PMID: 20237305 DOI: 10.1152/ajpregu.00188.2010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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19
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Vangjeli C, Clarke N, Quinn U, Dicker P, Tighe O, Ho C, O'Brien E, Stanton AV. Confirmation That the Renin Gene Distal Enhancer Polymorphism
REN
-5312C/T Is Associated With Increased Blood Pressure. ACTA ACUST UNITED AC 2010; 3:53-9. [DOI: 10.1161/circgenetics.109.899930] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Background—
Studies of knockout and transgenic mice have demonstrated key roles for genes encoding components of the renin angiotensin system in blood pressure regulation. However, whether polymorphisms in these genes contribute to the cause of essential hypertension in humans is still a matter of debate.
Methods and Results—
We performed an experiment with dense tagging single-nucleotide polymorphism coverage of 4 genes encoding proteins that control the overall activity of the cascade, namely renin, angiotensinogen, angiotensin-converting enzyme, and angiotensin-converting enzyme 2, in 2 Irish populations. Both clinic and 24-hour ambulatory blood pressure measurements were available from population I (n=387), whereas just clinic blood pressure was measured in population II (n=1024). Of the 23 polymorphisms genotyped, only a single renin gene polymorphism, REN-5312C/T, showed consistent statistically significant associations with elevated diastolic pressures. Carriage of one REN-5312T allele was associated with the following age- and sex-adjusted increments in diastolic pressures (mean [95% CI]): population I, clinic, 1.5 mm Hg (0.3 to 2.8); daytime, 1.4 mm Hg (0.4 to 2.4); night-time, 1.3 mm Hg (0.4 to 2.3), and population II, clinic, 1.1 mm Hg (0.1 to 2.1). Haplotypic analyses and multivariate stepwise regression analyses were in concordance with individual single-nucleotide polymorphism analyses.
Conclusions—
The REN-5312T allele had been shown previously to result in increased in vitro expression of the renin gene. We have now shown, in 2 independent populations, that carriage of a REN-5312T allele is associated with elevated diastolic blood pressure. These data provide evidence that renin is an important susceptibility gene for arterial hypertension in whites.
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Affiliation(s)
- Ciara Vangjeli
- From the Molecular and Cellular Therapeutics (C.V., N.C., U.Q., O.T., C.H., A.S.), Royal College of Surgeons in Ireland; Division of Population Health Sciences (P.D.), Department of Epidemiology and Public Health Medicine, Royal College of Surgeons in Ireland; and the Conway Institute of Biomolecular and Biomedical Research (E.B.), University College Dublin, Belfield, Dublin, Ireland
| | - Niamh Clarke
- From the Molecular and Cellular Therapeutics (C.V., N.C., U.Q., O.T., C.H., A.S.), Royal College of Surgeons in Ireland; Division of Population Health Sciences (P.D.), Department of Epidemiology and Public Health Medicine, Royal College of Surgeons in Ireland; and the Conway Institute of Biomolecular and Biomedical Research (E.B.), University College Dublin, Belfield, Dublin, Ireland
| | - Ursula Quinn
- From the Molecular and Cellular Therapeutics (C.V., N.C., U.Q., O.T., C.H., A.S.), Royal College of Surgeons in Ireland; Division of Population Health Sciences (P.D.), Department of Epidemiology and Public Health Medicine, Royal College of Surgeons in Ireland; and the Conway Institute of Biomolecular and Biomedical Research (E.B.), University College Dublin, Belfield, Dublin, Ireland
| | - Patrick Dicker
- From the Molecular and Cellular Therapeutics (C.V., N.C., U.Q., O.T., C.H., A.S.), Royal College of Surgeons in Ireland; Division of Population Health Sciences (P.D.), Department of Epidemiology and Public Health Medicine, Royal College of Surgeons in Ireland; and the Conway Institute of Biomolecular and Biomedical Research (E.B.), University College Dublin, Belfield, Dublin, Ireland
| | - Orna Tighe
- From the Molecular and Cellular Therapeutics (C.V., N.C., U.Q., O.T., C.H., A.S.), Royal College of Surgeons in Ireland; Division of Population Health Sciences (P.D.), Department of Epidemiology and Public Health Medicine, Royal College of Surgeons in Ireland; and the Conway Institute of Biomolecular and Biomedical Research (E.B.), University College Dublin, Belfield, Dublin, Ireland
| | - Clara Ho
- From the Molecular and Cellular Therapeutics (C.V., N.C., U.Q., O.T., C.H., A.S.), Royal College of Surgeons in Ireland; Division of Population Health Sciences (P.D.), Department of Epidemiology and Public Health Medicine, Royal College of Surgeons in Ireland; and the Conway Institute of Biomolecular and Biomedical Research (E.B.), University College Dublin, Belfield, Dublin, Ireland
| | - Eoin O'Brien
- From the Molecular and Cellular Therapeutics (C.V., N.C., U.Q., O.T., C.H., A.S.), Royal College of Surgeons in Ireland; Division of Population Health Sciences (P.D.), Department of Epidemiology and Public Health Medicine, Royal College of Surgeons in Ireland; and the Conway Institute of Biomolecular and Biomedical Research (E.B.), University College Dublin, Belfield, Dublin, Ireland
| | - Alice V. Stanton
- From the Molecular and Cellular Therapeutics (C.V., N.C., U.Q., O.T., C.H., A.S.), Royal College of Surgeons in Ireland; Division of Population Health Sciences (P.D.), Department of Epidemiology and Public Health Medicine, Royal College of Surgeons in Ireland; and the Conway Institute of Biomolecular and Biomedical Research (E.B.), University College Dublin, Belfield, Dublin, Ireland
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20
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Gomez RA, Pentz ES, Jin X, Cordaillat M, Sequeira Lopez MLS. CBP and p300 are essential for renin cell identity and morphological integrity of the kidney. Am J Physiol Heart Circ Physiol 2009; 296:H1255-62. [PMID: 19252086 DOI: 10.1152/ajpheart.01266.2008] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The mechanisms that govern the identity of renin cells are not well understood. We and others have identified cAMP as an important pathway in the regulation of renin synthesis and release. Recently, experiments in cells from the renin lineage led us to propose that acquisition and maintenance of renin cell identity are mediated by cAMP and histone acetylation at the cAMP responsive element (CRE) of the renin gene. Ultimately, the transcriptional effects of cAMP depend on binding of the appropriate transcription factors to CRE. It has been suggested that access of transcription factors to this region of the promoter is facilitated by the coactivators CREB-binding protein (CBP) and p300, which possess histone acetyltransferase activity and may be, in turn, responsible for the remodeling of chromatin underlying expression of the renin gene. We hypothesized that CBP and p300 are therefore required for expression of the renin gene and maintenance of the renin cell. Because mice homozygous for the deletion of CBP or p300 die before kidney organogenesis begins, no data on kidney or juxtaglomerular cell development in these mice are available. Therefore, to define the role of these histone acetyltransferases in renin cell identity in vivo, we used a conditional deletion approach, in which floxed CBP and p300 mice were crossed with mice expressing cre recombinase in renin cells. Results show that the histone acetyltransferases CBP and p300 are necessary for maintenance of renin cell identity and structural integrity of the kidney.
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Affiliation(s)
- R Ariel Gomez
- Dept. of Pediatrics, Univ. of Virginia School of Medicine, 409 Lane Rd., MR4 2001, Charlottesville, VA 22908, USA.
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21
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Abstract
The renin-angiotensin system (RAS) is critically involved in the regulation of the salt and volume status of the body and blood pressure. The activity of the RAS is controlled by the protease renin, which is released from the renal juxtaglomerular epithelioid cells into the circulation. Renin release is regulated in negative feedback-loops by blood pressure, salt intake, and angiotensin II. Moreover, sympathetic nerves and renal autacoids such as prostaglandins and nitric oxide stimulate renin secretion. Despite numerous studies there remained substantial gaps in the understanding of the control of renin release at the organ or cellular level. Some of these gaps have been closed in the last years by means of gene-targeted mice and advanced imaging and electrophysiological methods. In our review, we discuss these recent advances together with the relevant previous literature on the regulation of renin release.
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22
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Circulating versus tissue renin-angiotensin system: On the origin of (pro)renin. Curr Hypertens Rep 2008; 10:112-8. [DOI: 10.1007/s11906-008-0022-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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23
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Tanimoto K, Sugiura A, Kanafusa S, Saito T, Masui N, Yanai K, Fukamizu A. A single nucleotide mutation in the mouse renin promoter disrupts blood pressure regulation. J Clin Invest 2008; 118:1006-16. [PMID: 18259612 DOI: 10.1172/jci33824] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2007] [Accepted: 12/12/2007] [Indexed: 01/17/2023] Open
Abstract
Renin, a major regulatory component of the renin-angiotensin system, plays a pivotal role in regulating blood pressure and electrolyte homeostasis and is predominantly expressed in the kidney. Several cAMP-responsive elements have been identified within renin gene promoters. Here, we study how 2 such elements, renin proximal promoter element-2 (RP-2) and overlapping cAMP and negative regulatory elements (CNRE), affect the transcriptional regulation of renin. We generated Tg mice (TgM) bearing BACs containing either WT or mutant RP-2 or CNRE, integrated at single chromosomal loci. Analysis of the TgM revealed that RP-2 was essential to basal promoter activity in the kidney, while renin mRNA levels did not significantly change in any tissues tested in the CNRE mutant TgM. To evaluate the physiological significance of these mutations, we used the BAC Tg to rescue hypotensive Renin-null mutant mice. As predicted, no renin expression was observed in the kidneys of RP-2 mutant/Renin-null compound mice, whereas renin expression in CNRE mutant compound mice was indistinguishable from that in control mice. Consistent with this, RP-2 mutant animals were hypotensive, while CNRE mutants had normal blood pressure. Thus, transcriptional regulation of renin expression via RP-2 but not CNRE is critical for blood pressure regulation by this gene.
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Affiliation(s)
- Keiji Tanimoto
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
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24
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Peters J. Secretory and cytosolic (pro)renin in kidney, heart, and adrenal gland. J Mol Med (Berl) 2008; 86:711-4. [PMID: 18368380 DOI: 10.1007/s00109-008-0328-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2008] [Revised: 02/12/2008] [Accepted: 02/13/2008] [Indexed: 10/22/2022]
Abstract
Renin is commonly known as a secretory glycoprotein, which is expressed, stored, and secreted in a regulated manner by the kidney. The rat kidney exclusively expresses secretory renin. In this organ, renin regulates glomerular filtration rate, vascular resistance, and sodium reabsorbtion. In the adult rat heart, secretory preprorenin is not expressed. Instead, an alternative renin transcript is expressed that encodes for a previously unrecognized cytosolic renin. The expression of cytosolic but not of secretory renin increases markedly after myocardial infarction, indicating a role specifically for cytosolic renin in postischemic repair processes. In the adrenal gland, secretory renin is expressed and provides the basis for an intra-adrenal angiotensin (ANG) II amplification system. This amplification system reduces the demand for circulating ANGII to stimulate aldosterone production and thus minimizes any detrimental effects of circulating ANGII in other tissues. The adrenal gland additionally expresses cytosolic renin, which is targeted to mitochondria. Adrenal cytosolic renin increases aldosterone production plasma renin independently.
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Affiliation(s)
- Jörg Peters
- Institute of Physiology, University of Greifswald, Greifswalder Strasse 11C, Karlsburg, Germany.
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25
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Abstract
The aspartyl-protease renin is the key regulator of the renin-angiotensin-aldosterone system, which is critically involved in salt, volume, and blood pressure homeostasis of the body. Renin is mainly produced and released into circulation by the so-called juxtaglomerular epithelioid cells, located in the walls of renal afferent arterioles at the entrance of the glomerular capillary network. It has been known for a long time that renin synthesis and secretion are stimulated by the sympathetic nerves and the prostaglandins and are inhibited in negative feedback loops by angiotensin II, high blood pressure, salt, and volume overload. In contrast, the events controlling the function of renin-secreting cells at the organ and cellular level are markedly less clear and remain mysterious in certain aspects. The unravelling of these mysteries has led to new and interesting insights into the process of renin release.
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Affiliation(s)
- Frank Schweda
- Institute of Physiology, University of Regensburg, Germany; and
| | - Ulla Friis
- Department of Physiology and Pharmacology, Southern Denmark University at Odense, Odense, Denmark
| | | | - Ole Skott
- Department of Physiology and Pharmacology, Southern Denmark University at Odense, Odense, Denmark
| | - Armin Kurtz
- Institute of Physiology, University of Regensburg, Germany; and
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26
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Billet S, Bardin S, Verp S, Baudrie V, Michaud A, Conchon S, Muffat-Joly M, Escoubet B, Souil E, Hamard G, Bernstein KE, Gasc JM, Elghozi JL, Corvol P, Clauser E. Gain-of-function mutant of angiotensin II receptor, type 1A, causes hypertension and cardiovascular fibrosis in mice. J Clin Invest 2007; 117:1914-25. [PMID: 17607364 PMCID: PMC1890996 DOI: 10.1172/jci28764] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Accepted: 04/24/2007] [Indexed: 01/06/2023] Open
Abstract
The role of the renin-angiotensin system has been investigated by overexpression or inactivation of its different genes in animals. However, there is no data concerning the effect of the constitutive activation of any component of the system. A knockin mouse model has been constructed with a gain-of-function mutant of the Ang II receptor, type 1A (AT(1A)), associating a constitutively activating mutation (N111S) with a C-terminal deletion, which impairs receptor internalization and desensitization. In vivo consequences of this mutant receptor expression in homozygous mice recapitulate its in vitro characteristics: the pressor response is more sensitive to Ang II and longer lasting. These mice present with a moderate (~20 mmHg) and stable increase in BP. They also develop early and progressive renal fibrosis and cardiac fibrosis and diastolic dysfunction. However, there was no overt cardiac hypertrophy. The hormonal parameters (low-renin and inappropriately normal aldosterone productions) mimic those of low-renin human hypertension. This new model reveals that a constitutive activation of AT(1A) leads to cardiac and renal fibrosis in spite of a modest effect on BP and will be useful for investigating the role of Ang II in target organs in a model similar to some forms of human hypertension.
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Affiliation(s)
- Sandrine Billet
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U567, Paris, France.
Faculté de Médecine Paris Descartes, INSERM U652, Université Paris Descartes, Paris, France.
INSERM U36, Collège de France, Paris, France.
INSERM IFR02, Centre d’Explorations Fonctionnelles Intégrées, Université Denis Diderot, Paris, France.
INSERM U772, Collège de France, Assistance Publique Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Paris, France.
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Sabine Bardin
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U567, Paris, France.
Faculté de Médecine Paris Descartes, INSERM U652, Université Paris Descartes, Paris, France.
INSERM U36, Collège de France, Paris, France.
INSERM IFR02, Centre d’Explorations Fonctionnelles Intégrées, Université Denis Diderot, Paris, France.
INSERM U772, Collège de France, Assistance Publique Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Paris, France.
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Sonia Verp
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U567, Paris, France.
Faculté de Médecine Paris Descartes, INSERM U652, Université Paris Descartes, Paris, France.
INSERM U36, Collège de France, Paris, France.
INSERM IFR02, Centre d’Explorations Fonctionnelles Intégrées, Université Denis Diderot, Paris, France.
INSERM U772, Collège de France, Assistance Publique Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Paris, France.
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Véronique Baudrie
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U567, Paris, France.
Faculté de Médecine Paris Descartes, INSERM U652, Université Paris Descartes, Paris, France.
INSERM U36, Collège de France, Paris, France.
INSERM IFR02, Centre d’Explorations Fonctionnelles Intégrées, Université Denis Diderot, Paris, France.
INSERM U772, Collège de France, Assistance Publique Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Paris, France.
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Annie Michaud
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U567, Paris, France.
Faculté de Médecine Paris Descartes, INSERM U652, Université Paris Descartes, Paris, France.
INSERM U36, Collège de France, Paris, France.
INSERM IFR02, Centre d’Explorations Fonctionnelles Intégrées, Université Denis Diderot, Paris, France.
INSERM U772, Collège de France, Assistance Publique Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Paris, France.
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Sophie Conchon
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U567, Paris, France.
Faculté de Médecine Paris Descartes, INSERM U652, Université Paris Descartes, Paris, France.
INSERM U36, Collège de France, Paris, France.
INSERM IFR02, Centre d’Explorations Fonctionnelles Intégrées, Université Denis Diderot, Paris, France.
INSERM U772, Collège de France, Assistance Publique Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Paris, France.
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Martine Muffat-Joly
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U567, Paris, France.
Faculté de Médecine Paris Descartes, INSERM U652, Université Paris Descartes, Paris, France.
INSERM U36, Collège de France, Paris, France.
INSERM IFR02, Centre d’Explorations Fonctionnelles Intégrées, Université Denis Diderot, Paris, France.
INSERM U772, Collège de France, Assistance Publique Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Paris, France.
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Brigitte Escoubet
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U567, Paris, France.
Faculté de Médecine Paris Descartes, INSERM U652, Université Paris Descartes, Paris, France.
INSERM U36, Collège de France, Paris, France.
INSERM IFR02, Centre d’Explorations Fonctionnelles Intégrées, Université Denis Diderot, Paris, France.
INSERM U772, Collège de France, Assistance Publique Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Paris, France.
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Evelyne Souil
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U567, Paris, France.
Faculté de Médecine Paris Descartes, INSERM U652, Université Paris Descartes, Paris, France.
INSERM U36, Collège de France, Paris, France.
INSERM IFR02, Centre d’Explorations Fonctionnelles Intégrées, Université Denis Diderot, Paris, France.
INSERM U772, Collège de France, Assistance Publique Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Paris, France.
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Ghislaine Hamard
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U567, Paris, France.
Faculté de Médecine Paris Descartes, INSERM U652, Université Paris Descartes, Paris, France.
INSERM U36, Collège de France, Paris, France.
INSERM IFR02, Centre d’Explorations Fonctionnelles Intégrées, Université Denis Diderot, Paris, France.
INSERM U772, Collège de France, Assistance Publique Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Paris, France.
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Kenneth E. Bernstein
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U567, Paris, France.
Faculté de Médecine Paris Descartes, INSERM U652, Université Paris Descartes, Paris, France.
INSERM U36, Collège de France, Paris, France.
INSERM IFR02, Centre d’Explorations Fonctionnelles Intégrées, Université Denis Diderot, Paris, France.
INSERM U772, Collège de France, Assistance Publique Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Paris, France.
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Jean Marie Gasc
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U567, Paris, France.
Faculté de Médecine Paris Descartes, INSERM U652, Université Paris Descartes, Paris, France.
INSERM U36, Collège de France, Paris, France.
INSERM IFR02, Centre d’Explorations Fonctionnelles Intégrées, Université Denis Diderot, Paris, France.
INSERM U772, Collège de France, Assistance Publique Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Paris, France.
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Jean-Luc Elghozi
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U567, Paris, France.
Faculté de Médecine Paris Descartes, INSERM U652, Université Paris Descartes, Paris, France.
INSERM U36, Collège de France, Paris, France.
INSERM IFR02, Centre d’Explorations Fonctionnelles Intégrées, Université Denis Diderot, Paris, France.
INSERM U772, Collège de France, Assistance Publique Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Paris, France.
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Pierre Corvol
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U567, Paris, France.
Faculté de Médecine Paris Descartes, INSERM U652, Université Paris Descartes, Paris, France.
INSERM U36, Collège de France, Paris, France.
INSERM IFR02, Centre d’Explorations Fonctionnelles Intégrées, Université Denis Diderot, Paris, France.
INSERM U772, Collège de France, Assistance Publique Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Paris, France.
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Eric Clauser
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, INSERM U567, Paris, France.
Faculté de Médecine Paris Descartes, INSERM U652, Université Paris Descartes, Paris, France.
INSERM U36, Collège de France, Paris, France.
INSERM IFR02, Centre d’Explorations Fonctionnelles Intégrées, Université Denis Diderot, Paris, France.
INSERM U772, Collège de France, Assistance Publique Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Paris, France.
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
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27
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Dikeakos JD, Reudelhuber TL. Sending proteins to dense core secretory granules: still a lot to sort out. ACTA ACUST UNITED AC 2007; 177:191-6. [PMID: 17438078 PMCID: PMC2064127 DOI: 10.1083/jcb.200701024] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The intracellular sorting of peptide hormone precursors to the dense core secretory granules (DCSGs) is essential for their bioactivation. Despite the fundamental importance of this cellular process, the nature of the sorting signals for entry of proteins into DCSGs remains a source of vigorous debate. This review highlights recent discoveries that are consistent with a model in which several protein domains, acting in a cell-specific fashion and at different steps in the sorting process, act in concert to regulate the entry of proteins into DCSGs.
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Affiliation(s)
- Jimmy D Dikeakos
- Laboratory of Molecular Biochemistry of Hypertension, Clinical Research Institute of Montreal, Montreal, Quebec H2W 1R7, Canada
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28
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Esch JHV, Danser AJ. Local Angiotensin Generation and AT2 Receptor Activation. FRONTIERS IN RESEARCH OF THE RENIN-ANGIOTENSIN SYSTEM ON HUMAN DISEASE 2007. [PMCID: PMC7119946 DOI: 10.1007/978-1-4020-6372-5_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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29
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Adams DJ, Head GA, Markus MA, Lovicu FJ, van der Weyden L, Ko¨ntgen F, Arends MJ, Thiru S, Mayorov DN, Morris BJ. Renin Enhancer Is Critical for Control of Renin Gene Expression and Cardiovascular Function. J Biol Chem 2006. [DOI: 10.1016/s0021-9258(19)84090-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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30
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Adams DJ, Head GA, Markus MA, Lovicu FJ, van der Weyden L, Köntgen F, Arends MJ, Thiru S, Mayorov DN, Morris BJ. Renin enhancer is critical for control of renin gene expression and cardiovascular function. J Biol Chem 2006; 281:31753-61. [PMID: 16895910 DOI: 10.1074/jbc.m605720200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The important cardiovascular regulator renin contains a strong in vitro enhancer 2.7 kb upstream of its gene. Here we tested the in vivo role of the mouse Ren-1c enhancer. In renin-expressing As4.1 cells stably transfected with Ren-1c promoter with or without enhancer, expression of linked beta-geo reporter, stable expression, and colony formation were dependent on the presence of the enhancer. We then generated mice carrying a targeted deletion of the enhancer (REKO mice) and found marked depletion of renin in renal juxtaglomerular and submandibular ductal cells, as well as hyperplasia of macula densa cells. Plasma creatinine was increased, but electrolytes were normal. Male REKO mice implanted with telemetry devices had 9 +/- 1 mm Hg lower mean arterial pressure (p < 0.001), which was partly normalized by a high NaCl diet. Locomotor activity was lower, and baroreflex sensitivity was normal. Markedly reduced mean arterial pressure variability in the midfrequency band indicated a contribution of reduced sympathetic vasomotor tone to the hypotension. In conclusion, the renin enhancer is critical for renin gene expression and physiological sequelae, including response to alteration in salt intake. The REKO mouse may be useful as a low renin expression model.
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Affiliation(s)
- David J Adams
- School of Medical Sciences and Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
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31
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Bagnall AJ, Kelland NF, Gulliver-Sloan F, Davenport AP, Gray GA, Yanagisawa M, Webb DJ, Kotelevtsev YV. Deletion of Endothelial Cell Endothelin B Receptors Does Not Affect Blood Pressure or Sensitivity to Salt. Hypertension 2006; 48:286-93. [PMID: 16801484 DOI: 10.1161/01.hyp.0000229907.58470.4c] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Endothelin B receptors in different tissues regulate diverse physiological responses including vasoconstriction, vasodilatation, clearance of endothelin-1, and renal tubular sodium reabsorption. To examine the role of endothelial cell endothelin B receptors in these processes, we generated endothelial cell-specific endothelin B receptor knockout mice using a Cre-
loxP
approach. We have demonstrated loss of endothelial cell endothelin B receptor expression and function and preservation of nonendothelial endothelin B receptor-mediated responses through binding and functional assays. Ablation of endothelin B receptors exclusively from endothelial cells produces endothelial dysfunction in the absence of hypertension, with evidence of decreased endogenous release of NO and increased plasma endothelin-1. In contrast to models of total endothelin B receptor ablation, the blood pressure response to a high-salt diet is unchanged in endothelial cell–specific endothelin B receptor knockouts compared with control floxed mice. These findings suggest that the endothelial cell endothelin B receptor mediates a tonic vasodilator effect and that nonendothelial cell endothelin B receptors are important for the regulation of blood pressure.
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Affiliation(s)
- Alan J Bagnall
- Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, Little France Crescent, Edinburgh, EH16 4TJ United Kingdom.
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32
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Abstract
In this review, we outline the application and contribution of transgenic technology to establishing the genetic basis of blood pressure regulation and its dysfunction. Apart from a small number of examples where high blood pressure is the result of single gene mutation, essential hypertension is the sum of interactions between multiple environmental and genetic factors. Candidate genes can be identified by a variety of means including linkage analysis, quantitative trait locus analysis, association studies, and genome-wide scans. To test the validity of candidate genes, it is valuable to model hypertension in laboratory animals. Animal models generated through selective breeding strategies are often complex, and the underlying mechanism of hypertension is not clear. A complementary strategy has been the use of transgenic technology. Here one gene can be selectively, tissue specifically, or developmentally overexpressed, knocked down, or knocked out. Although resulting phenotypes may still be complicated, the underlying genetic perturbation is a starting point for identifying interactions that lead to hypertension. We recognize that the development and maintenance of hypertension may involve many systems including the vascular, cardiac, and central nervous systems. However, given the central role of the kidney in normal and abnormal blood pressure regulation, we intend to limit our review to models with a broadly renal perspective.
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Affiliation(s)
- Linda J Mullins
- Molecular Physiology Laboratory, Centre for Cardiovascular Science, Queens Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
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33
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Yang T, Huang YG, Ye W, Hansen P, Schnermann JB, Briggs JP. Influence of genetic background and gender on hypertension and renal failure in COX-2-deficient mice. Am J Physiol Renal Physiol 2004; 288:F1125-32. [PMID: 15613621 DOI: 10.1152/ajprenal.00219.2004] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present study was undertaken to determine whether the severity of renal failure or hypertension in homozygous cyclooxygenase (COX)-2-deficient (COX-2-/-) mice affected by genetic background or gender. COX-2 deletion was introduced into three congenic genetic backgrounds, 129/Sv (129/COX-2-/-), C57/BL6 (C57/COX-2-/-), and BALB/c (BALB/COX-2-/-), by backcrossing the original mixed-background knockout mice with the respective inbred strains for 9 or 10 generations. Evaluation of the severity of hypertension and renal failure was performed in knockout and wild-type mice at the age of 2.5-3.5 mo. Blood pressure measured by tail-cuff plethysmography was significantly elevated in the male 129/COX-2-/- mice (165.8 +/- 9.2 vs. 116 +/- 5.1 mmHg, P < 0.05), and to a much lesser extent in the female 129/COX-2-/- mice (127.4 +/- 3.3 vs. 102.4 +/- 3.3), whereas it was unchanged in the C57- or BALB/COX-2-/- mice regardless of gender. Urinary excretion of albumin, determined by EIA, was remarkably increased in the 129/COX-2-/- (16.4 +/- 4.1 vs. 0.16 +/- 0.043 mg albumin/mg creatinine, P < 0.001), and to a lesser extent in the male C57/COX-2-/- mice (0.595 +/- 0.416 vs. 0.068 +/- 0.019). Albumin excretion was not elevated in the male BALB/COX-2-/- or in female COX-2-/- mice on any of the three genetic backgrounds. Histological analysis showed abundant protein casts, dilated tubules, and infiltration of inflammatory cells in the male 129/COX-2-/- mice, but not in COX-2-/- mice in other strains or gender. However, the presence of small glomeruli in the nephrogenic zone was observed in all strains of COX-2 knockout mice, regardless of genetic background and gender. Therefore, we conclude that the severity of hypertension and renal failure in COX-2-deficient mice is influenced by genetic background and gender, whereas the incomplete maturation of outer cortical nephrons appears to be independent of genetic background effects.
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Affiliation(s)
- Tianxin Yang
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA.
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34
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Hansen PB, Yang T, Huang Y, Mizel D, Briggs J, Schnermann J. Plasma renin in mice with one or two renin genes. ACTA ACUST UNITED AC 2004; 181:431-7. [PMID: 15283755 DOI: 10.1111/j.1365-201x.2004.01315.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIM In the present study we have investigated whether the presence of a second renin gene exerts an overriding influence on plasma renin such that mice with two renin genes have consistently higher renin levels than mice with only one renin gene. METHODS Plasma renin was determined as the rate of angiotensin I generation using a radioimmunoassay (RIA) kit with (plasma renin concentration, PRC) or without (plasma renin activity, PRA) the addition of purified rat angiotensinogen as substrate. RESULTS In male 129SvJ, DBA/2 and Swiss Webster mice, strains possessing both Ren-1 and Ren-2, PRC (ng Ang I mL(-1) h(-1)) averaged 178 +/- 36, 563 +/- 57 and 550 +/- 43 while PRA was 2.9 +/- 0.5, 3.6 +/- 0.8 and 7.8 +/- 1.2. In male C57BL/6, C3H and BALB/c mice that express only Ren-1, PRC averaged 426 +/- 133, 917 +/- 105 and 315 +/- 72, and PRA was 3.4 +/- 1.0, 6.9 +/- 1.7 and 4.5 +/- 1.2. In the two renin gene A1AR-/- mice compared with the one renin gene A1AR+/+, PRC averaged 538 +/- 321 and 415 +/- 159 while PRA averaged 3.2 +/- 1.1 and 4.4 +/- 1.4 ng Ang I mL(-1) h(-1). Aldosterone levels showed no significant differences between one renin (C57BL/6, C3H and BALB/c) and two renin (129SvJ, DBA/2 and Swiss Webster) gene mice. Furthermore, by quantitative real-time polymerase chain reaction (RT-PCR) we found no correlation between the number of renin genes and whole kidney renin mRNA levels from one and two renin gene mice. CONCLUSION Our data show that baseline plasma renin is not systematically higher in mice with two renin genes than in one renin gene mice. Thus, the presence of a second renin gene does not seem to be a major determinant of differences in PRC between different mouse strains.
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Affiliation(s)
- P B Hansen
- National Institute of Diabetes, and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA
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35
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Lum C, Shesely EG, Potter DL, Beierwaltes WH. Cardiovascular and renal phenotype in mice with one or two renin genes. Hypertension 2003; 43:79-86. [PMID: 14662650 DOI: 10.1161/01.hyp.0000107401.72456.50] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We compared the phenotype of two common mouse models, C-57BL/6J (C57), which carries only the Ren-1c gene, and 129/SvJ (Sv-129), with both Ren 1d and Ren-2. We hypothesized two renin gene Sv-129 would have increased blood pressure and the renin-angiotensin system would be more influential in regulating renal function compared with one renin gene mice. Sv-129 consistently had higher blood pressure than C-57, whether conscious (128 versus 108 mm Hg, P<0.001) or anesthetized (102 versus 88 mm Hg, P<0.001). Plasma renin concentration in both conscious and anesthetized C-57 mice was 3- to 4-fold higher than in Sv-129 (P<0.05), whereas renal cortical renin content was 2.5-fold higher (P<0.005). Renal blood flow and renal vascular resistance were the same in C-57 and Sv-129. Exogenous angiotensinogen produced identical pressor and renal vasoconstrictor responses in both strains. Blocking AT1 receptors with losartan reduced blood pressure by 19 mm Hg in both strains. Nitric oxide synthase inhibition by l-NAME increased blood pressure by 29 mm Hg in C-57 and 35 mm Hg in Sv-129 mice, but the decrease in renal blood flow was 30% less in C-57 (P<0.025). We conclude that Sv-129 mice with two renin genes have higher blood pressure but lower plasma and renal renin than C-57 mice with one renin gene. Renin substrate may limit angiotensin II production in the mouse. In Sv-129, the influence of nitric oxide on renal but not systemic resistance may be exaggerated. Renin from Ren-2 may act independently of normal renin control mechanisms.
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Affiliation(s)
- Craig Lum
- Hypertension and Vascular Research Division, Henry Ford Hospital, Detroit Medical Campus of Case Western Reserve University School of Medicine, Detroit, Mich, USA
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36
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Rybicki AC, Fabry ME, Does MD, Kaul DK, Nagel RL. Differential gene expression in the kidney of sickle cell transgenic mice: upregulated genes. Blood Cells Mol Dis 2003; 31:370-80. [PMID: 14636654 DOI: 10.1016/j.bcmd.2003.08.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The S+S-Antilles transgenic mouse used in this study has renal defects similar to those seen in sickle cell anemia patients: congested glomeruli, medullary fibrosis, renal enlargement, vasoocclusion, and a urine concentrating defect. We used gene expression microarrays to identify genes highly up-regulated in the kidneys of these mice and validated their expression by real-time PCR. Kidney hypoxia, as demonstrated by the presence of deoxyhemoglobin, was detected by blood oxygen dependent magnetic resonance imaging (BOLD-MRI). Some of the up-regulated genes included cytochrome P450 4a14, glutathione-S-transferase alpha-1, mitochondrial hydroxymethylglutaryl CoA synthase, cytokine inducible SH-2 containing protein, retinol dehydrogenase type III, arginase II, glycolate oxidase, Na/K ATPase, renin-1, and alkaline phosphatase 2. An increase in enzyme activity was also demonstrated for one of the up-regulated genes (arginase II). These genes can be integrated into several different pathophysiological processes: a hypoxia cascade, a replacement cascade, or an ameliorating cascade, one or all of which may explain the phenotype of this disease. We conclude that microarray technology is a powerful tool to identify genes involved in renal disease in sickle cell anemia and that the identification of various metabolic pathways may open new avenues for therapeutic interventions.
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Affiliation(s)
- Anne C Rybicki
- Department of Medicine, Division of Hematology, Albert Einstein College of Medicine/Montefiore Medical Center, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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37
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Pentz ES, Moyano MA, Thornhill BA, Sequeira Lopez MLS, Gomez RA. Ablation of renin-expressing juxtaglomerular cells results in a distinct kidney phenotype. Am J Physiol Regul Integr Comp Physiol 2003; 286:R474-83. [PMID: 14563659 DOI: 10.1152/ajpregu.00426.2003] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Renin-expressing cells are peculiar in that they act as differentiated cells, producing the hormone renin, while they also seem to act as progenitors for other renal cell types. As such, they may have functions independent of their ability to generate renin/angiotensin. To test this hypothesis, we ablated renin-expressing cells during development by placing diphtheria toxin A chain (DTA) under control of the Ren1d mouse renin promoter by homologous recombination in a two-renin gene strain (Ren2 and Ren1d). Renin-expressing cells are essentially absent from kidneys in homozygotes (DTA/DTA) which, unlike wild-type mice, are unable to recruit renin-expressing cells when homeostasis is threatened. In contrast, renin staining in the submandibular gland (SMG), which expresses mainly Ren2, is normal. Homozygous mice survive normally, but the kidneys are small and have morphological abnormalities: 25% of the glomeruli are hyperplastic or atrophic, tubules are dilated and atrophic, and areas of undifferentiated cells exist near the atrophic glomeruli and tubules. However, in contrast to the very abnormal renal vessels found when renin-angiotensin system genes are deleted, the kidney vessels in homozygotes have normal wall thickness and no decrease in lumen size. Homozygotes have severely reduced kidney and plasma renin concentrations and females have reduced blood pressure. Homozygotes have elevated blood urea nitrogen and potassium levels, which are suggestive of altered renal function. We conclude that renin cells per se are necessary for the morphological integrity of the kidney and may have a role in maintenance of normal kidney function.
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Affiliation(s)
- Ellen Steward Pentz
- Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA
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38
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Cole JM, Xiao H, Adams JW, Disher KM, Zhao H, Bernstein KE. New approaches to genetic manipulation of mice: tissue-specific expression of ACE. Am J Physiol Renal Physiol 2003; 284:F599-607. [PMID: 12620918 DOI: 10.1152/ajprenal.00308.2002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The renin-angiotensin system (RAS) plays a central role in body physiology, controlling blood pressure and blood electrolyte composition. ACE.1 (null) mice are null for all expression of angiotensin-converting enzyme (ACE). These mice have low blood pressure, the inability to concentrate urine, and a maldevelopment of the kidney. In contrast, ACE.2 (tissue null) mice produce one-third normal plasma ACE but no tissue ACE. They also have low blood pressure and cannot concentrate urine, but they have normal indices of renal function. These mice, while very informative, show that the null approach to creating knockout mice has intrinsic limitations given the many different physiological systems that no longer operate in an animal without a functioning RAS. To investigate the fine control of body physiology by the RAS, we developed a novel promoter swapping approach to generate a more selective tissue knockout of ACE expression. We used this to create ACE.3 (liver ACE) mice that selectively express ACE in the liver but lack all ACE within the vasculature. Evaluation of these mice shows that endothelial expression of ACE is not required for blood pressure control or normal renal function. Targeted homologous recombination has the power to create new strains of mice expressing the RAS in selected subsets of tissues. Not only will these new genetic models be useful for studying blood pressure regulation but also they show great promise for the investigation of the function of the RAS in complicated disease models.
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Affiliation(s)
- Justin M Cole
- Department of Pathology, Emory University, Atlanta, Georgia 30322, USA
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39
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Lochard N, Silversides DW, van Kats JP, Mercure C, Reudelhuber TL. Brain-specific restoration of angiotensin II corrects renal defects seen in angiotensinogen-deficient mice. J Biol Chem 2003; 278:2184-9. [PMID: 12399452 DOI: 10.1074/jbc.m209933200] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mice deficient for angiotensinogen (AGT), or other components of the renin-angiotensin system, show a high rate of neonatal mortality correlated with severe renal abnormalities including hydronephrosis, hypertrophy of renal arteries, and an impaired ability to concentrate urine. Although transgenic replacement of systemic or adipose, but not renal, AGT in AGT-deficient mice has previously been reported to correct some of these renal abnormalities, the tissue target for this complementation has not been defined. In the current study, we have used a novel transgenic strategy to restore the peptide product of the renin-angiotensin system, angiotensin II, exclusively in the brain of AGT-deficient mice and demonstrate that brain-specific angiotensin II can correct the hydronephrosis and partially correct renal dysfunction seen in AGT-deficient mice. Taken together, these results suggest that the renin-angiotensin system affects renal development and function through systemically accessible targets in the brain.
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Affiliation(s)
- Nadheige Lochard
- Laboratory of Molecular Biochemistry of Hypertension, Clinical Research Institute of Montreal, Quebec H2W 1R7, Canada
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40
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Caron KMI, James LR, Kim HS, Morham SG, Sequeira Lopez MLS, Gomez RA, Reudelhuber TL, Smithies O. A genetically clamped renin transgene for the induction of hypertension. Proc Natl Acad Sci U S A 2002; 99:8248-52. [PMID: 12034874 PMCID: PMC123053 DOI: 10.1073/pnas.112222199] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Experimental analysis of the effects of individual components of complex mammalian systems is frequently impeded by compensatory adjustments that animals make to achieve homeostasis. We here introduce a genetic procedure for eliminating this type of impediment, by using as an example the development and testing of a transgene for "genetically clamping" the expression of renin, the major homeostatically responding component of the renin-angiotensin system, one of the most important regulators of blood pressure. To obtain a renin transgene whose expression is genetically clamped at a constant level, we have used single-copy chosen-site gene targeting to insert into a liver-specific locus a single copy of a modified mouse renin transgene driven by a liver-specific promoter/enhancer. The resulting transgene expresses renin ectopically at a constant high level in the liver and leads to elevated plasma levels of prorenin and active renin. The transgenic mice display high blood pressure, enhanced thirst, high urine output, proteinuria, and kidney damage. Treatment with the angiotensin II type I receptor antagonist, losartan, reduces the hypertension, albuminuria, and kidney damage, but does not affect expression of the transgene. This genetically clamped renin transgene can be used in models in which hypertension and its complications need to be investigated in a high prorenin/renin environment that is not subject to homeostatic compensations by the animal when other factors are changed.
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Affiliation(s)
- Kathleen M I Caron
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
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41
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Wang Q, Hummler E, Nussberger J, Clément S, Gabbiani G, Brunner HR, Burnier M. Blood pressure, cardiac, and renal responses to salt and deoxycorticosterone acetate in mice: role of Renin genes. J Am Soc Nephrol 2002; 13:1509-16. [PMID: 12039980 DOI: 10.1097/01.asn.0000017902.77985.84] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Several studies have demonstrated that mice are polymorphic for the number of renin genes, with some inbred strains harboring one gene (Ren-1(c)) and other strains containing two genes (Ren-1(d) and Ren-2). In this study, the effects of 1% salt and deoxycorticosterone acetate (DOCA)/salt were investigated in one- and two-renin gene mice, for elucidation of the role of renin in the modulation of BP, cardiac, and renal responses to salt and DOCA. The results demonstrated that, under baseline conditions, mice with two renin genes exhibited 10-fold higher plasma renin activity, 100-fold higher plasma renin concentrations, elevated BP (which was angiotensin II-dependent), and an increased cardiac weight index, compared with one-renin gene mice (all P < 0.01). The presence of two renin genes markedly increased the BP, cardiac, and renal responses to salt. The number of renin genes also modulated the responses to DOCA/salt. In one-renin gene mice, DOCA/salt induced significant renal and cardiac hypertrophy (P < 0.01) even in the absence of any increase in BP. Treatment with losartan, an angiotensin II AT(1) receptor antagonist, decreased BP in two-renin gene mice but not in one-renin gene mice. However, losartan prevented the development of cardiac hypertrophy in both groups of mice. In conclusion, these data demonstrate that renin genes are important determinants of BP and of the responses to salt and DOCA in mice. The results confirm that the Ren-2 gene, which controls renin production mainly in the submaxillary gland, is physiologically active in mice and is not subject to the usual negative feedback control. Finally, these data provide further evidence that mineralocorticoids promote cardiac hypertrophy even in the absence of BP changes. This hypertrophic process is mediated in part by the activation of angiotensin II AT(1) receptors.
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Affiliation(s)
- Qing Wang
- Division of Hypertension and Vascular Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
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42
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Abstract
With advances in genetic manipulation and molecular biological and physiological techniques, the mouse has become the animal model of choice for studying the genetic basis of human diseases. The two most commonly used methods for analyzing the function of a gene in vivo, overexpression (transgenic mouse) and deletion (knockout mouse), have been extremely useful in establishing the importance of genes in genetic disorders. The renin-angiotensin system (RAS) is one of the most widely studied systems controlling blood pressure. Although the primary site of Ang-II production is the plasma, all the components of the RAS cascade are expressed in many tissues, including the brain. This review briefly summarizes systemic and tissue-specific transgenic and knockout mouse models of the RAS for determining the role of this system in the regulation of blood pressure and in the pathogenesis of hypertension, with a focus on the RAS in the brain.
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Affiliation(s)
- Satoshi Morimoto
- Departments of Internal Medicine and Physiology & Biophisics, the University of Iowa College of Medicine, Iowa City, IA 52242, USA
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43
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Beierwaltes WH, Potter DL, Shesely EG. Renal baroreceptor-stimulated renin in the eNOS knockout mouse. Am J Physiol Renal Physiol 2002; 282:F59-64. [PMID: 11739113 DOI: 10.1152/ajprenal.0144.2001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The role of endothelium-derived nitric oxide (NO) in renal baroreceptor stimulation of renin was tested comparing endothelial nitric oxide synthase (eNOS)-deficient mice with C57BL/6J (C57) controls. We measured blood pressure, renal blood flow (RBF), and plasma renin concentration (PRC) in Inactin-anesthetized mice. Blood pressure in eNOS knockout mice was higher than in controls (100 +/- 3 vs. 86 +/- 1 mmHg, respectively; P < 0.001), but RBF was similar (1.71 +/- 0.06 vs. 1.66 +/- 0.09 ml. min(-1). 100 mg kidney wt(-1), respectively), so that renal vascular resistance was also higher in the knockouts (59.81 +/- 2.07 vs. 51.81 +/- 2.66 resistance units, respectively; P < 0.025). PRC was similar (8.24 +/- 1.57 in eNOS knockouts vs. 7.10 +/- 1.19 ng ANG I. ml(-1). h(-1) in C57). NOS inhibition with nitro-L-arginine methyl ester (L-NAME) in C57 controls increased blood pressure (from 85 +/- 2 to 106 +/- 1 mmHg, P < 0.001) and decreased RBF (from 1.66 +/- 0.09 to 1.08 +/- 0.02; P < 0.005), but L-NAME had no effect in eNOS knockout mice. When renal perfusion pressure was reduced in C57 controls to 55 mmHg, PRC increased from 6.6 +/- 0.9 to 14.5 +/- 1.9 microg. ml(-1). h(-1) (P < 0.025), but this response was blocked by L-NAME. However, in eNOS knockouts, reduced renal perfusion pressure increased PRC from 7.6 +/- 1.4 to 15.0 +/- 2.8 microg. ml(-1). h(-1) (P < 0.001). Thus in the chronic absence of eNOS, blood pressure was elevated, but RBF was normal. Additionally, the absence of eNOS did not modify baroreceptor-stimulated renin, suggesting that eNOS-derived NO does not directly mediate this renin-regulating pathway.
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Affiliation(s)
- William H Beierwaltes
- Hypertension and Vascular Research Division, Henry Ford Hospital, Detroit Medical Campus of Case Western Reserve School of Medicine, Detroit, Michigan 48202, USA
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Cholewa BC, Mattson DL. Role of the renin-angiotensin system during alterations of sodium intake in conscious mice. Am J Physiol Regul Integr Comp Physiol 2001; 281:R987-93. [PMID: 11507017 DOI: 10.1152/ajpregu.2001.281.3.r987] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present studies were performed to quantify circulating components of the renin-angiotensin-aldosterone axis and to determine the functional importance of this system during alterations in sodium intake in conscious mice. Increasing sodium intake from approximately 200 to 1,000 microeq/day significantly decreased plasma renin concentration from 472 +/- 96 to 304 +/- 83 ng ANG I. ml(-1). h(-1) (n = 5) but did not alter plasma renin activity from the low-sodium level of 7.7 +/- 1.1 ng ANG I. ml(-1). h(-1). Despite the elevated plasma renin concentration, plasma ANG II in mice on low-sodium level averaged 14 +/- 3 pg/ml and was significantly suppressed to 6 +/- 1 pg/ml by high-sodium intake (n = 7). Consistent with the modulation of ANG II, plasma aldosterone significantly decreased from 41 +/- 8 to 8 +/- 3 ng/dl when sodium intake was elevated (n = 6). In a final set of experiments, the continuous infusion of ANG II (20 ng. kg(-1). min(-1)) led to a mild salt-sensitive increase in mean arterial pressure from 108 +/- 2 to 131 +/- 2 mmHg as sodium intake was varied from low to high (n = 7). In vehicle-infused mice, mean arterial pressure was unaltered from 109 +/- 2 mmHg when sodium intake was increased (n = 6). These studies indicate that the physiological suppression of circulating ANG II may be required to maintain a constancy of arterial pressure during alterations in sodium intake in normal mice.
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Affiliation(s)
- B C Cholewa
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
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Doan TN, Gletsu N, Cole J, Bernstein KE. Genetic manipulation of the renin-angiotensin system. Curr Opin Nephrol Hypertens 2001; 10:483-91. [PMID: 11458029 DOI: 10.1097/00041552-200107000-00002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The renin-angiotensin system is widely known for its importance in control of blood pressure, electrolyte homeostasis and volume regulation. Recently, renin-angiotensin system function was studied using homologous recombination in embryonic stem cells to manipulate the mouse genome. Angiotensinogen, angiotensin-converting enzyme and angiotensin II receptors were each eliminated in separate lines of mice. These null animals share similar phenotypes, such as a lowering of blood pressure, abnormal renal development, malfunction of the kidney and, unexpectedly, a decrease in hematocrit. In addition, angiotensin-converting enzyme null male mice sire far smaller litters than male wild-type mice. This suggests an unexplored role for angiotensin-converting enzyme in conception. Future studies with these and other genetically engineered mice lines will reveal novel physiological effects of angiotensin II.
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Affiliation(s)
- T N Doan
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
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Pentz ES, Lopez ML, Kim HS, Carretero O, Smithies O, Gomez RA. Ren1d and Ren2 cooperate to preserve homeostasis: evidence from mice expressing GFP in place of Ren1d. Physiol Genomics 2001; 6:45-55. [PMID: 11395546 DOI: 10.1152/physiolgenomics.2001.6.1.45] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To distinguish the contributions of Ren1(d) and Ren2 to kidney development and blood pressure homeostasis, we placed green fluorescent protein (GFP) under control of the Ren1(d) renin locus by homologous recombination in mice. Homozygous Ren1(d)-GFP animals make GFP mRNA in place of Ren1(d) mRNA in the kidney and maintain Ren2 synthesis in the juxtaglomerular (JG) cells. GFP expression provides an accurate marker of Ren1(d) expression during development. Kidneys from homozygous animals are histologically normal, although with fewer secretory granules in the JG cells. Blood pressure and circulating renin are reduced in Ren1(d)-GFP homozygotes. Acute administration of losartan decreases blood pressure further, suggesting a role for Ren2 protein in blood pressure homeostasis. These studies demonstrate that, in the absence of Ren1(d), Ren2 preserves normal kidney development and prevents severe hypotension. Chronic losartan treatment results in compensation via recruitment of both Ren1(d)- and Ren2-expressing cells along the preglomerular vessels. This response is achieved by metaplastic transformation of arteriolar smooth muscle cells, a major mechanism to control renin bioavailability and blood pressure homeostasis.
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Affiliation(s)
- E S Pentz
- Department of Pediatrics, University of Virginia, Charlottesville, Virginia 22908, USA
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47
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Woods LL, Ingelfinger JR, Nyengaard JR, Rasch R. Maternal protein restriction suppresses the newborn renin-angiotensin system and programs adult hypertension in rats. Pediatr Res 2001; 49:460-7. [PMID: 11264427 DOI: 10.1203/00006450-200104000-00005] [Citation(s) in RCA: 402] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Restriction of maternal protein intake during rat pregnancy produces offspring that are hypertensive in adulthood, but the mechanisms are not well understood. Our purpose was to determine whether this adult hypertension could be programmed during development by suppression of the fetal/newborn renin-angiotensin system (RAS) and a consequent reduction in nephron number. Pregnant rats were fed a normal protein (19%, NP) or low-protein (8.5%, LP) diet throughout gestation. Birth weight was reduced by 13% (p < 0.0005), and the kidney/body weight ratio was reduced in LP pups. Renal renin mRNA levels were significantly reduced in newborn LP pups; renal renin concentration and renin immunostaining were suppressed. Renal tissue angiotensin II levels were also suppressed in newborn LP (0.079 +/- 0.002 ng/mg, LP versus 0.146 +/- 0.016 ng/mg, NP, p < 0.01). Mean arterial pressure in conscious, chronically instrumented adult offspring (21 wk) was higher in LP (135 +/- 1 mm Hg, LP versus 126 +/- 1 mm Hg, NP, p < 0.00007), and GFR normalized to kidney weight was reduced in LP (p < 0.04). The number of glomeruli per kidney was lower in adult LP offspring (21,567 +/- 1,694, LP versus 28,917 +/- 2,342, NP, p < 0.03), and individual glomerular volume was higher (1.81 +/- 0.16 10(6) microm(3), LP versus 1.11 +/- 0.10 10(6) microm(3), NP, p < 0.005); the total volume of all glomeruli per kidney was not significantly different. Thus, perinatal protein restriction in the rat suppresses the newborn intrarenal RAS and leads to a reduced number of glomeruli, glomerular enlargement, and hypertension in the adult.
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Affiliation(s)
- L L Woods
- Division of Nephrology, Oregon Health Sciences University, 3181 S.W. Sam Jackson Park Rd., Portland, Oregon 97201-3098, U.S.A.
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Perera EM, Martin H, Seeherunvong T, Kos L, Hughes IA, Hawkins JR, Berkovitz GD. Tescalcin, a novel gene encoding a putative EF-hand Ca(2+)-binding protein, Col9a3, and renin are expressed in the mouse testis during the early stages of gonadal differentiation. Endocrinology 2001; 142:455-63. [PMID: 11145610 DOI: 10.1210/endo.142.1.7882] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
To identify genes that are differentially expressed in the developing testis we used representational difference analysis of complementary DNA from gonads of mouse embryos at 13.5 days postcoitum (dpc). Three genes were identified. One of them was a novel gene termed tescalcin that encoded a putative EF-hand Ca(2+)-binding protein. The open reading frame consisted of 642 nucleotides encoding a protein with 214 amino acids. Analysis of the predicted amino acid sequence revealed an N:-myristoylation motif and several phosphorylation sites in addition to an EF-hand Ca(2+)-binding domain. TESCALCIN: messenger RNA (mRNA) was present in fetal testis, but not in ovary or mesonephros, and was restricted to the testicular cords. Its expression was first detected in the male gonad at 11.5 dpc and demonstrated a pattern consistent with a role in the testis at the early stages of testis differentiation. Tescalcin is expressed in the testis of Kit(W/W-v) mice, indicating that it is not dependent on the presence of germ cells. The other two genes identified were collagen IX alpha3 (Col9a3) and RENIN: Col9a3 expression was present at low levels in male and female gonads at 11.5 dpc. Thereafter, it was markedly up-regulated in the male, but remained very low in the female. Expression of Col9a3 was restricted to testicular cords and was also detected in testis of Kit(W/W-v) mice. RENIN: mRNA was first detected in testis at 12.5 dpc, increased thereafter, and reached a peak at 16.5 dpc. RENIN: mRNA was localized in cells of the interstitium and cells at the border between the gonad and mesonephros. Expression of RENIN: in the ovary was not detected using standard conditions.
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Affiliation(s)
- E M Perera
- Division of Pediatric Endocrinology, Department of Pediatrics, University of Miami School of Medicine, Miami, Florida 33136, USA.
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49
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Mullins LJ, Payne CM, Kotelevtseva N, Brooker G, Fleming S, Harris S, Mullins JJ. Granulation rescue and developmental marking of juxtaglomerular cells using "piggy-BAC" recombination of the mouse ren locus. J Biol Chem 2000; 275:40378-84. [PMID: 10995772 DOI: 10.1074/jbc.m007315200] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mice lacking a functional Ren-1(d) gene exhibit a complete lack of renal juxtaglomerular cell granulation and atypical macula densa morphology. Transgenic mice carrying a 145-kilobase BAC clone encompassing the Ren-1(d) and Ren-2 loci were generated, characterized, and backcrossed with Ren-1(d-/-) mice. Homozygous Ren-1(d)-null mice expressing the BAC clone exhibited complete restoration of normal renal structure. Homologous recombination in Escherichia coli was used to generate a modified version of the BAC clone, in which an IRESbeta-geo cassette was inserted specifically into the Ren-1(d) gene. When introduced into the germline, the modified clone provided a marker for juxtaglomerular cell differentiation and beta-geo was expressed appropriately in juxtaglomerular cells throughout development. Parallel backcross experiments onto the Ren-1(d)-null background demonstrated that the juxtaglomerular cells expressed the modified Ren-1(d) locus in the absence of regranulation. These data demonstrate that the nongranulated cells constitute bona fide juxtaglomerular cells despite their altered morphology, that overexpression of renin-2 cannot compensate for the loss of renin-1(d), and that primary structural differences between the two isoforms are responsible for the differences in granulation. The use of BAC modification as part of functional complementation studies illustrates the potential for in vivo molecular dissection of key physiological mechanisms.
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Affiliation(s)
- L J Mullins
- Molecular Physiology Laboratory, Wilkie Building, University of Edinburgh Medical School, Teviot Place, Edinburgh, United Kingdom
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50
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Smithies O, Kim HS, Takahashi N, Edgell MH. Importance of quantitative genetic variations in the etiology of hypertension. Kidney Int 2000; 58:2265-80. [PMID: 11115061 DOI: 10.1046/j.1523-1755.2000.00411.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Recent progress has been remarkable in identifying mutations which cause diseases (mostly uncommon) that are inherited simply. Unfortunately, the common diseases of humankind with a strong genetic component, such as those affecting cardiovascular function, have proved less tractable. Their etiology is complex with substantial environmental components and strong indications that multiple genes are implicated. In this article, we consider the genetic etiology of essential hypertension. After presenting the distribution of blood pressures in the population, we propose the hypothesis that essential hypertension is the consequence of different combinations of genetic variations that are individually of little consequence. The candidate gene approach to finding relevant genes is exemplified by studies that identified potentially causative variations associated with quantitative differences in the expression of the angiotensinogen gene (AGT). Experiments to test causation directly are possible in mice, and we describe their use to establish that blood pressures are indeed altered by genetic changes in AGT expression. Tests of differences in expression of the genes coding for the angiotensin-converting enzyme (ACE) and for the natriuretic peptide receptor A are also considered, and we provide a tabulation of all comparable experiments in mice. Computer simulations are presented that resolve the paradoxical finding that while ACE inhibitors are effective, genetic variations in the expression of the ACE gene do not affect blood pressure. We emphasize the usefulness of studying animals heterozygous for an inactivating mutation and a wild-type allele, and briefly discuss a way of establishing causative links between complex phenotypes and single nucleotide polymorphisms.
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Affiliation(s)
- O Smithies
- Departments of Pathology and Microbiology, University of North Carolina, Chapel Hill, North Carolina 27599-7525, USA
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