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Hirohama D, Nishimoto M, Ayuzawa N, Kawarazaki W, Fujii W, Oba S, Shibata S, Marumo T, Fujita T. Activation of Rac1-Mineralocorticoid Receptor Pathway Contributes to Renal Injury in Salt-Loaded db/db Mice. Hypertension 2021; 78:82-93. [PMID: 34058848 DOI: 10.1161/hypertensionaha.121.17263] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Daigoro Hirohama
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Japan (D.H., M.N., N.A., W.K., S.O., S.S., T.M., T.F.).,Division of Nephrology, Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan (D.H., W.F., S.S.)
| | - Mitsuhiro Nishimoto
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Japan (D.H., M.N., N.A., W.K., S.O., S.S., T.M., T.F.).,Department of Internal Medicine, International University of Health and Welfare Mita Hospital, Tokyo, Japan (M.N.)
| | - Nobuhiro Ayuzawa
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Japan (D.H., M.N., N.A., W.K., S.O., S.S., T.M., T.F.)
| | - Wakako Kawarazaki
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Japan (D.H., M.N., N.A., W.K., S.O., S.S., T.M., T.F.)
| | - Wataru Fujii
- Division of Nephrology, Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan (D.H., W.F., S.S.)
| | - Shigeyoshi Oba
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Japan (D.H., M.N., N.A., W.K., S.O., S.S., T.M., T.F.)
| | - Shigeru Shibata
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Japan (D.H., M.N., N.A., W.K., S.O., S.S., T.M., T.F.).,Division of Nephrology, Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan (D.H., W.F., S.S.)
| | - Takeshi Marumo
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Japan (D.H., M.N., N.A., W.K., S.O., S.S., T.M., T.F.).,Department of Pharmacology, School of Medicine, International University of Health and Welfare, Chiba, Japan (T.M.)
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Japan (D.H., M.N., N.A., W.K., S.O., S.S., T.M., T.F.).,Shinshu University School of Medicine (T.F.), Shinshu University, Nagano, Japan.,Research Center for Social Systems (T.F.), Shinshu University, Nagano, Japan
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Abstract
Dietary salt intake increases blood pressure (BP) but the salt sensitivity of BP differs between individuals. The interplay of ageing, genetics and environmental factors, including malnutrition and stress, contributes to BP salt sensitivity. In adults, obesity is often associated with salt-sensitive hypertension. The children of women who experience malnutrition during pregnancy are at increased risk of developing obesity, diabetes and salt-sensitive hypertension as adults. Similarly, the offspring of mice that are fed a low-protein diet during pregnancy develop salt-sensitive hypertension in association with aberrant DNA methylation of the gene encoding type 1A angiotensin II receptor (AT1AR) in the hypothalamus, leading to upregulation of hypothalamic AT1AR and renal sympathetic overactivity. Ageing is also associated with salt-sensitive hypertension. In aged mice, promoter methylation leads to reduced kidney production of the anti-ageing factor Klotho and a decrease in circulating soluble Klotho. In the setting of Klotho deficiency, salt-induced activation of the vascular Wnt5a-RhoA pathway leads to ageing-associated salt-sensitive hypertension, potentially as a result of reduced renal blood flow and increased peripheral resistance. Thus, kidney mechanisms and aberrant DNA methylation of certain genes are involved in the development of salt-sensitive hypertension during fetal development and old age. Three distinct paradigms of epigenetic memory operate on different timescales in prenatal malnutrition, obesity and ageing.
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Affiliation(s)
- Wakako Kawarazaki
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan. .,School of Medicine, Shinshu University, Matsumoto, Japan. .,Research Center for Social Systems, Shinshu University, Matsumoto, Japan.
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Abstract
A high amount of salt in the diet increases blood pressure (BP) and leads to salt-sensitive hypertension in individuals with impaired renal sodium excretion. Small guanosine triphosphatase (GTP)ase Rho and Rac, activated by salt intake, play important roles in the pathogenesis of salt-sensitive hypertension as key switches of intracellular signaling. Focusing on Rho, high salt intake in the central nervous system increases sodium concentrations of cerebrospinal fluid in salt-sensitive subjects via Rho/Rho kinase and renin-angiotensin system activation and causes increased brain salt sensitivity and sympathetic nerve outflow in BP control centers. In vascular smooth muscle cells, Rho-guanine nucleotide exchange factors and Rho determine sensitivity to vasoconstrictors such as angiotensin II (Ang II), and facilitate vasoconstriction via G-protein and Wnt pathways, leading to increased vascular resistance, including in the renal arteries, in salt-sensitive subjects with high salt intake. In the vascular endothelium, Rho/Rho kinase inhibits nitric oxide (NO) production and function, and high salt amounts further augment Rho activity via asymmetric dimethylarginine, an endogenous inhibitor of NO synthetase, causing aberrant relaxation and increased vascular tone. Rho-associated mechanisms are deeply involved in the development of salt-sensitive hypertension, and their further elucidation can help in developing effective protection and new therapies.
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Kawarazaki W, Mizuno R, Nishimoto M, Ayuzawa N, Hirohama D, Ueda K, Kawakami-Mori F, Oba S, Marumo T, Fujita T. Salt causes aging-associated hypertension via vascular Wnt5a under Klotho deficiency. J Clin Invest 2021; 130:4152-4166. [PMID: 32597829 DOI: 10.1172/jci134431] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 04/24/2020] [Indexed: 12/13/2022] Open
Abstract
Aging is associated with a high prevalence of hypertension due to elevated susceptibility of BP to dietary salt, but its mechanism is unknown. Serum levels of Klotho, an anti-aging factor, decline with age. We found that high salt (HS) increased BP in aged mice and young heterozygous Klotho-knockout mice and was associated with increased vascular expression of Wnt5a and p-MYPT1, which indicate RhoA activity. Not only the Wnt inhibitor LGK974 and the Wnt5a antagonist Box5 but Klotho supplementation inhibits HS-induced BP elevation, similarly to the Rho kinase inhibitor fasudil, associated with reduced p-MYPT1 expression in both groups of mice. In cultured vascular smooth muscle cells, Wnt5a and angiotensin II (Ang II) increased p-MYPT1 expression but knockdown of Wnt5a with siRNA abolished Ang II-induced upregulation of p-MYPT1, indicating that Wnt5a is indispensable for Ang II-induced Rho/ROCK activation. Notably, Klotho inhibited Wnt5a- and Ang II-induced upregulation of p-MYPT1. Consistently, Klotho supplementation ameliorated HS-induced augmentation of reduced renal blood flow (RBF) response to intra-arterial infusion of Ang II and the thromboxane A2 analog U46619, which activated RhoA in both groups of mice and were associated with the inhibition of BP elevation, suggesting that abnormal response of RBF to Ang II contributes to HS-induced BP elevation. Thus, Klotho deficiency underlies aging-associated salt-sensitive hypertension through vascular non-canonical Wnt5a/RhoA activation.
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Affiliation(s)
- Wakako Kawarazaki
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Risuke Mizuno
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, University of Tokyo, Meguro-ku, Tokyo, Japan.,Department of Veterinary Pharmacology, Faculty of Veterinary Medicine, Okayama University of Science, Imabari, Ehime, Japan
| | - Mitsuhiro Nishimoto
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Nobuhiro Ayuzawa
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Daigoro Hirohama
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Kohei Ueda
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Fumiko Kawakami-Mori
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Shigeyoshi Oba
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Takeshi Marumo
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, University of Tokyo, Meguro-ku, Tokyo, Japan.,Shinshu University School of Medicine and.,Research Center for Social Systems, Shinshu University, Matsumoto, Nagano, Japan
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Marumo T, Hoshino J, Kawarazaki W, Nishimoto M, Ayuzawa N, Hirohama D, Yamanouchi M, Ubara Y, Okaneya T, Fujii T, Yuki K, Atsumi Y, Sato A, Arai E, Kanai Y, Shimosawa T, Fujita T. Methylation pattern of urinary DNA as a marker of kidney function decline in diabetes. BMJ Open Diabetes Res Care 2020; 8:e001501. [PMID: 32883689 PMCID: PMC7473659 DOI: 10.1136/bmjdrc-2020-001501] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/07/2020] [Accepted: 07/25/2020] [Indexed: 01/25/2023] Open
Abstract
INTRODUCTION Renal tubular injury contributes to the decline in kidney function in patients with diabetes. Cell type-specific DNA methylation patterns have been used to calculate proportions of particular cell types. In this study, we developed a method to detect renal tubular injury in patients with diabetes by detecting exfoliated tubular cells shed into the urine based on tubular cell-specific DNA methylation patterns. RESEARCH DESIGN AND METHODS We identified DNA methylation patterns specific for human renal proximal tubular cells through compartment-specific methylome analysis. We next determined the methylation levels of proximal tubule-specific loci in urine sediment of patients with diabetes and analyzed correlation with clinical variables. RESULTS We identified genomic loci in SMTNL2 and G6PC to be selectively unmethylated in human proximal tubular cells. The methylation levels of SMTNL2 and G6PC in urine sediment, deemed to reflect the proportion of exfoliated proximal tubular cells due to injury, correlated well with each other. Methylation levels of SMTNL2 in urine sediment significantly correlated with the annual decline in estimated glomerular filtration rate. Moreover, addition of urinary SMTNL2 methylation to a model containing known risk factors significantly improved discrimination of patients with diabetes with faster estimated glomerular filtration rate decline. CONCLUSIONS This study demonstrates that patients with diabetes with continual loss in kidney function may be stratified by a specific DNA methylation signature through epigenetic urinalysis and provides further evidence at the level of exfoliated cells in the urine that injury of proximal tubular cells may contribute to pathogenesis of diabetic kidney disease.
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Affiliation(s)
- Takeshi Marumo
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo, Japan
- Department of Pharmacology, School of Medicine, International University of Health and Welfare, Narita, Chiba, Japan
| | - Junichi Hoshino
- Nephrology Center, Toranomon Hospital, Minato-ku, Tokyo, Japan
| | - Wakako Kawarazaki
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Mitsuhiro Nishimoto
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Nobuhiro Ayuzawa
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Daigoro Hirohama
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo, Japan
| | | | - Yoshifumi Ubara
- Nephrology Center, Toranomon Hospital Kajigaya, Kawasaki, Kanagawa, Japan
| | | | - Takeshi Fujii
- Department of Pathology, Toranomon Hospital, Minato-ku, Tokyo, Japan
| | - Kazunari Yuki
- Diabetes Center, Eiju General Hospital, Taito-ku, Tokyo, Japan
| | | | - Atsuhisa Sato
- Department of Internal Medicine, School of Medicine, International University of Health and Welfare, Minata-ku, Tokyo, Japan
| | - Eri Arai
- Department of Pathology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
| | - Yae Kanai
- Department of Pathology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
| | - Tatsuo Shimosawa
- Department of Clinical Laboratory, School of Medicine, International University of Health and Welfare, Minato-ku, Tokyo, Japan
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo, Japan
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Hirohama D, Kawarazaki W, Nishimoto M, Ayuzawa N, Marumo T, Shibata S, Fujita T. PGI 2 Analog Attenuates Salt-Induced Renal Injury through the Inhibition of Inflammation and Rac1-MR Activation. Int J Mol Sci 2020; 21:ijms21124433. [PMID: 32580367 PMCID: PMC7353033 DOI: 10.3390/ijms21124433] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/18/2020] [Accepted: 06/18/2020] [Indexed: 12/18/2022] Open
Abstract
Renal inflammation is known to be involved in salt-induced renal damage, leading to end-stage renal disease. This study aims to evaluate the role of inflammation in anti-inflammatory and renoprotective effects of beraprost sodium (BPS), a prostaglandin I2 (PGI2) analog, in Dahl salt-sensitive (DS) rats. Five-week-old male DS rats were fed a normal-salt diet (0.5% NaCl), a high-salt diet (8% NaCl), or a high-salt diet plus BPS treatment for 3 weeks. BPS treatment could inhibit marked proteinuria and renal injury in salt-loaded DS rats with elevated blood pressure, accompanied by renal inflammation suppression. Notably, high salt increased renal expression of active Rac1, followed by increased Sgk1 expressions, a downstream molecule of mineralocorticoid receptor (MR) signal, indicating salt-induced activation of Rac1-MR pathway. However, BPS administration inhibited salt-induced Rac1-MR activation as well as renal inflammation and damage, suggesting that Rac1-MR pathway is involved in anti-inflammatory and renoprotective effects of PGI2. Based upon Rac1 activated by inflammation, moreover, BPS inhibited salt-induced activation of Rac1-MR pathway by renal inflammation suppression, resulting in the attenuation of renal damage in salt-loaded DS rats. Thus, BPS is efficacious for the treatment of salt-induced renal injury.
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Affiliation(s)
- Daigoro Hirohama
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan; (W.K.); (M.N.); (N.A.); (T.M.); (S.S.); (T.F.)
- Division of Nephrology, Department of Internal Medicine, Teikyo University School of Medicine, Tokyo 173-8606, Japan
- Correspondence: ; Tel.: +81-3-5452-5057
| | - Wakako Kawarazaki
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan; (W.K.); (M.N.); (N.A.); (T.M.); (S.S.); (T.F.)
| | - Mitsuhiro Nishimoto
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan; (W.K.); (M.N.); (N.A.); (T.M.); (S.S.); (T.F.)
- Department of Internal Medicine, International University of Health and Welfare Mita Hospital, Tokyo 108-8329, Japan
| | - Nobuhiro Ayuzawa
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan; (W.K.); (M.N.); (N.A.); (T.M.); (S.S.); (T.F.)
| | - Takeshi Marumo
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan; (W.K.); (M.N.); (N.A.); (T.M.); (S.S.); (T.F.)
- Center for Basic Medical Research at Narita Campus, International University of Health and Welfare, Chiba 286-8686, Japan
| | - Shigeru Shibata
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan; (W.K.); (M.N.); (N.A.); (T.M.); (S.S.); (T.F.)
- Division of Nephrology, Department of Internal Medicine, Teikyo University School of Medicine, Tokyo 173-8606, Japan
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan; (W.K.); (M.N.); (N.A.); (T.M.); (S.S.); (T.F.)
- Shinshu University School of Medicine and Research Center for Social Systems, Nagano 389-0111, Japan
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Kawarazaki H, Ishibashi Y, Kawarazaki W, Shimizu H, Takara Y, Kume H, Sasahira N, Kaname S, Fujita T. Successful Management of Catheter Obstruction by Endoscopic Naso-Pancreatic Drainage Tube. ARCH ESP UROL 2020. [DOI: 10.1177/089686080702700419] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- H. Kawarazaki
- Division of Total Renal Care Medicine University of Tokyo School of Medicine Tokyo, Japan
- Department of Nephrology and Endocrinology University of Tokyo School of Medicine Tokyo, Japan
| | - Y. Ishibashi
- Division of Total Renal Care Medicine University of Tokyo School of Medicine Tokyo, Japan
- Department of Nephrology and Endocrinology University of Tokyo School of Medicine Tokyo, Japan
| | - W. Kawarazaki
- Division of Total Renal Care Medicine University of Tokyo School of Medicine Tokyo, Japan
- Department of Nephrology and Endocrinology University of Tokyo School of Medicine Tokyo, Japan
| | - H. Shimizu
- Division of Total Renal Care Medicine University of Tokyo School of Medicine Tokyo, Japan
- Department of Nephrology and Endocrinology University of Tokyo School of Medicine Tokyo, Japan
| | - Y. Takara
- Division of Total Renal Care Medicine University of Tokyo School of Medicine Tokyo, Japan
- Department of Nephrology and Endocrinology University of Tokyo School of Medicine Tokyo, Japan
| | - H. Kume
- Department of Urology University of Tokyo School of Medicine Tokyo, Japan
| | - N. Sasahira
- Department of Gastroenterology University of Tokyo School of Medicine Tokyo, Japan
| | - S. Kaname
- Division of Total Renal Care Medicine University of Tokyo School of Medicine Tokyo, Japan
- Department of Nephrology and Endocrinology University of Tokyo School of Medicine Tokyo, Japan
| | - T. Fujita
- Division of Total Renal Care Medicine University of Tokyo School of Medicine Tokyo, Japan
- Department of Nephrology and Endocrinology University of Tokyo School of Medicine Tokyo, Japan
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Ayuzawa N, Nishimoto M, Ueda K, Hirohama D, Kawarazaki W, Shimosawa T, Marumo T, Fujita T. Two Mineralocorticoid Receptor-Mediated Mechanisms of Pendrin Activation in Distal Nephrons. J Am Soc Nephrol 2020; 31:748-764. [PMID: 32034107 DOI: 10.1681/asn.2019080804] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 12/27/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Regulation of sodium chloride transport in the aldosterone-sensitive distal nephron is essential for fluid homeostasis and BP control. The chloride-bicarbonate exchanger pendrin in β-intercalated cells, along with sodium chloride cotransporter (NCC) in distal convoluted tubules, complementarily regulate sodium chloride handling, which is controlled by the renin-angiotensin-aldosterone system. METHODS Using mice with mineralocorticoid receptor deletion in intercalated cells, we examined the mechanism and roles of pendrin upregulation via mineralocorticoid receptor in two different models of renin-angiotensin-aldosterone system activation. We also used aldosterone-treated NCC knockout mice to examine the role of pendrin regulation in salt-sensitive hypertension. RESULTS Deletion of mineralocorticoid receptor in intercalated cells suppressed the increase in renal pendrin expression induced by either exogenous angiotensin II infusion or endogenous angiotensin II upregulation via salt restriction. When fed a low-salt diet, intercalated cell-specific mineralocorticoid receptor knockout mice with suppression of pendrin upregulation showed BP reduction that was attenuated by compensatory activation of NCC. In contrast, upregulation of pendrin induced by aldosterone excess combined with a high-salt diet was scarcely affected by deletion of mineralocorticoid receptor in intercalated cells, but depended instead on hypokalemic alkalosis through the activated mineralocorticoid receptor-epithelial sodium channel cascade in principal cells. In aldosterone-treated NCC knockout mice showing upregulation of pendrin, potassium supplementation corrected alkalosis and inhibited the pendrin upregulation, thereby lowering BP. CONCLUSIONS In conjunction with NCC, the two pathways of pendrin upregulation, induced by angiotensin II through mineralocorticoid receptor activation in intercalated cells and by alkalosis through mineralocorticoid receptor activation in principal cells, play important roles in fluid homeostasis during salt depletion and salt-sensitive hypertension mediated by aldosterone excess.
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Affiliation(s)
- Nobuhiro Ayuzawa
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan;
| | - Mitsuhiro Nishimoto
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Kohei Ueda
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Daigoro Hirohama
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Wakako Kawarazaki
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Tatsuo Shimosawa
- Department of Clinical Laboratory, School of Medicine, International University of Health and Welfare, Chiba, Japan
| | - Takeshi Marumo
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan;
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Oba S, Ayuzawa N, Nishimoto M, Kawarazaki W, Ueda K, Hirohama D, Kawakami-Mori F, Shimosawa T, Marumo T, Fujita T. Aberrant DNA methylation of Tgfb1 in diabetic kidney mesangial cells. Sci Rep 2018; 8:16338. [PMID: 30397232 PMCID: PMC6218490 DOI: 10.1038/s41598-018-34612-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 10/22/2018] [Indexed: 01/19/2023] Open
Abstract
Epigenetic modulation may underlie the progression of diabetic nephropathy (DN). Involvement of TGFB1 in mesangial fibrosis of DN led us to hypothesize that Tgfb1 DNA demethylation contributes to progression of DN. In primary mesangial cells from diabetic (db/db) mouse kidneys, demethylation of Tgfb1 DNA and upregulation of Tgfb1 mRNA progressed simultaneously. USF1 binding site in Tgfb1 promoter region were demethylated, and binding of USF1 increased, with decreased binding of DNMT1 in db/db compared with control. Given downregulation of Tgfb1 expression by folic acid, antioxidant Tempol reversed DNA demethylation, with increased and decreased recruitment of DNMT1 and USF1 to the promoter, resulting in decreased Tgfb1 expression in db/db mice. Addition of H2O2 to mesangial cells induced DNA demethylation and upregulated Tgfb1 expression. Finally, Tempol attenuated mesangial fibrosis in db/db mice. We conclude that aberrant DNA methylation of Tgfb1 due to ROS overproduction play a key to mesangial fibrosis during DN progression.
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Affiliation(s)
- Shigeyoshi Oba
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.
| | - Nobuhiro Ayuzawa
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Mitsuhiro Nishimoto
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Wakako Kawarazaki
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Kohei Ueda
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Daigoro Hirohama
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | | | - Tatsuo Shimosawa
- Department of Clinical Laboratory, International University of Health and Welfare, School of Medicine, Mita Hospital IUHW, Tokyo, Japan
| | - Takeshi Marumo
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.
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10
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Kawakami-Mori F, Nishimoto M, Reheman L, Kawarazaki W, Ayuzawa N, Ueda K, Hirohama D, Kohno D, Oba S, Shimosawa T, Marumo T, Fujita T. Aberrant DNA methylation of hypothalamic angiotensin receptor in prenatal programmed hypertension. JCI Insight 2018; 3:95625. [PMID: 30385711 DOI: 10.1172/jci.insight.95625] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 09/27/2018] [Indexed: 12/12/2022] Open
Abstract
Maternal malnutrition, which causes prenatal exposure to excessive glucocorticoid, induces adverse metabolic programming, leading to hypertension in offspring. In offspring of pregnant rats receiving a low-protein diet or dexamethasone, a synthetic glucocorticoid, mRNA expression of angiotensin receptor type 1a (Agtr1a) in the paraventricular nucleus (PVN) of the hypothalamus was upregulated, concurrent with reduced expression of DNA methyltransferase 3a (Dnmt3a), reduced binding of DNMT3a to the Agtr1a gene, and DNA demethylation. Salt loading increased BP in both types of offspring, suggesting that elevated hypothalamic Agtr1a expression is epigenetically modulated by excessive glucocorticoid and leads to adult-onset salt-sensitive hypertension. Consistent with this, dexamethasone treatment of PVN cells upregulated Agtr1a, while downregulating Dnmt3a, and decreased DNMT3a binding and DNA demethylation at the Agtr1a locus. In addition, Dnmt3a knockdown upregulated Agtr1a independently of dexamethasone. Hypothalamic neuron-specific Dnmt3a-deficient mice exhibited upregulation of Agtr1a in the PVN and salt-induced BP elevation without dexamethasone treatment. By contrast, dexamethasone-treated Agtr1a-deficient mice failed to show salt-induced BP elevation, despite reduced expression of Dnmt3a. Thus, epigenetic modulation of hypothalamic angiotensin signaling contributes to salt-sensitive hypertension induced by prenatal glucocorticoid excess in offspring of mothers that are malnourished during pregnancy.
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Affiliation(s)
- Fumiko Kawakami-Mori
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Tokyo, Japan.,Division of Endocrinology, Mitsui Memorial Hospital, Tokyo, Japan
| | - Mitsuhiro Nishimoto
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Tokyo, Japan
| | - Latapati Reheman
- Department of Clinical Laboratory, International University of Health and Welfare, School of Medicine, Narita Hospital IUHW, Tokyo, Japan
| | - Wakako Kawarazaki
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Tokyo, Japan
| | - Nobuhiro Ayuzawa
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Tokyo, Japan
| | - Kohei Ueda
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Tokyo, Japan
| | - Daigoro Hirohama
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Tokyo, Japan
| | - Daisuke Kohno
- Advanced Scientific Research Leaders Development Unit, Gunma University, Gunma, Japan
| | - Shigeyoshi Oba
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Tokyo, Japan
| | - Tatsuo Shimosawa
- Department of Clinical Laboratory, International University of Health and Welfare, School of Medicine, Narita Hospital IUHW, Tokyo, Japan
| | - Takeshi Marumo
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Tokyo, Japan
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Tokyo, Japan
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11
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Watanabe A, Marumo T, Kawarazaki W, Nishimoto M, Ayuzawa N, Ueda K, Hirohama D, Tanaka T, Yagi S, Ota S, Nagae G, Aburatani H, Kumagai H, Fujita T. Aberrant DNA methylation of pregnane X receptor underlies metabolic gene alterations in the diabetic kidney. Am J Physiol Renal Physiol 2018; 314:F551-F560. [DOI: 10.1152/ajprenal.00390.2017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Epigenetic abnormalities have been suggested to mediate metabolic memory observed in diabetic complications. We have shown that epigenetic alterations may induce persistent phenotypic changes in the proximal tubules of the diabetic kidneys. In this study, we show that pregnane X receptor (PXR), a xenobiotic nuclear receptor, is epigenetically altered and upregulated and may have a possible function in the diabetic kidney. PXR has been shown to play a critical role in metabolic changes in obesity and diabetes; however, its distribution and function in the kidney are unknown. In the normal kidney, Pxr was selectively expressed in the proximal tubular cells with demethylation in the promoter DNA. In db/db mice, significant increases in Pxr mRNA, further demethylation of DNA, and stimulatory histone marks in the promoter were observed. Epigenetic changes are likely to play a causative role in PXR induction, since a DNA methyltransferase inhibitor increased PXR mRNA in cultured human proximal tubular cells. Administration of a PXR agonist increased mRNA levels of solute carrier organic anion transporter family member 2B1 ( Slco2b1), a xenobiotic transporter; response gene to complement 32 ( Rgc32), a molecule known to exert fibrotic effects in the kidney; and phosphoenolpyruvate carboxykinase 1 ( Pck1), a gluconeogenic enzyme in the kidney. The expressions of these genes were inhibited by PXR small interfering RNA in cultured proximal tubular cells. Increased mRNA levels of Slco2b1, Rgc32, and Pck1 were also observed in the kidney of db/db mice. These data indicate that PXR is upregulated in the diabetic kidney with aberrant epigenetic modifications and may modulate the course of diabetic kidney disease through the activation of these genes.
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Affiliation(s)
- Atsushi Watanabe
- Division of Clinical Epigenetics, The University of Tokyo, Tokyo, Japan
- Department of Nephrology and Endocrinology, National Defense Medical College, Saitama, Japan
| | - Takeshi Marumo
- Division of Clinical Epigenetics, The University of Tokyo, Tokyo, Japan
| | - Wakako Kawarazaki
- Division of Clinical Epigenetics, The University of Tokyo, Tokyo, Japan
| | | | - Nobuhiro Ayuzawa
- Division of Clinical Epigenetics, The University of Tokyo, Tokyo, Japan
| | - Kohei Ueda
- Division of Clinical Epigenetics, The University of Tokyo, Tokyo, Japan
| | - Daigoro Hirohama
- Division of Clinical Epigenetics, The University of Tokyo, Tokyo, Japan
| | - Toshiya Tanaka
- Laboratory for Systems Biology and Medicine, The University of Tokyo, Tokyo, Japan
| | - Shintaro Yagi
- Laboratory of Cellular Biochemistry, Department of Animal Resource Sciences/Veterinary Medical Sciences, The University of Tokyo, Tokyo, Japan
| | - Satoshi Ota
- Genome Science Division, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Genta Nagae
- Genome Science Division, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Hiroyuki Aburatani
- Genome Science Division, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Hiroo Kumagai
- Department of Nephrology and Endocrinology, National Defense Medical College, Saitama, Japan
| | - Toshiro Fujita
- Division of Clinical Epigenetics, The University of Tokyo, Tokyo, Japan
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12
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Hirohama D, Ayuzawa N, Ueda K, Nishimoto M, Kawarazaki W, Watanabe A, Shimosawa T, Marumo T, Shibata S, Fujita T. Aldosterone Is Essential for Angiotensin II-Induced Upregulation of Pendrin. J Am Soc Nephrol 2017; 29:57-68. [PMID: 29021385 DOI: 10.1681/asn.2017030243] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 07/18/2017] [Indexed: 12/17/2022] Open
Abstract
The renin-angiotensin-aldosterone system has an important role in the control of fluid homeostasis and BP during volume depletion. Dietary salt restriction elevates circulating angiotensin II (AngII) and aldosterone levels, increasing levels of the Cl-/HCO3- exchanger pendrin in β-intercalated cells and the Na+-Cl- cotransporter (NCC) in distal convoluted tubules. However, the independent roles of AngII and aldosterone in regulating these levels remain unclear. In C57BL/6J mice receiving a low-salt diet or AngII infusion, we evaluated the membrane protein abundance of pendrin and NCC; assessed the phosphorylation of the mineralocorticoid receptor, which selectively inhibits aldosterone binding in intercalated cells; and measured BP by radiotelemetry in pendrin-knockout and wild-type mice. A low-salt diet or AngII infusion upregulated NCC and pendrin levels, decreased the phosphorylation of mineralocorticoid receptor in β-intercalated cells, and increased plasma aldosterone levels. Notably, a low-salt diet did not alter BP in wild-type mice, but significantly decreased BP in pendrin-knockout mice. To dissect the roles of AngII and aldosterone, we performed adrenalectomies in mice to remove aldosterone from the circulation. In adrenalectomized mice, AngII infusion again upregulated NCC expression, but did not affect pendrin expression despite the decreased phosphorylation of mineralocorticoid receptor. By contrast, AngII and aldosterone coadministration markedly elevated pendrin levels in adrenalectomized mice. Our results indicate that aldosterone is necessary for AngII-induced pendrin upregulation, and suggest that pendrin contributes to the maintenance of normal BP in cooperation with NCC during activation of the renin-angiotensin-aldosterone system by dietary salt restriction.
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Affiliation(s)
- Daigoro Hirohama
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan;
| | - Nobuhiro Ayuzawa
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Kohei Ueda
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Mitsuhiro Nishimoto
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Wakako Kawarazaki
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Atsushi Watanabe
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Tatsuo Shimosawa
- Department of Clinical Laboratory, School of Medicine, International University of Health and Welfare, Chiba, Japan
| | - Takeshi Marumo
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Shigeru Shibata
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.,Division of Nephrology, Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan; and
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan; .,CREST, Japan Science and Technology Agency, Tokyo, Japan
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13
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Ueda K, Nishimoto M, Hirohama D, Ayuzawa N, Kawarazaki W, Watanabe A, Shimosawa T, Loffing J, Zhang MZ, Marumo T, Fujita T. Abstract 055: Systemic Effect of Renal 11β-HSD2 Deficiency on Blood Pressure Regulation. Hypertension 2017. [DOI: 10.1161/hyp.70.suppl_1.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
Renal mechanism of 11β-HSD2 deficiency for developing hypertension is to be evaluated because vascular mechanism associated with sympathetic nervous activity was prevailing in global
Hsd11b2
knockout (KO) mice although brain-specific KO mice needed high salt intake to develop hypertension. We have demonstrated the importance of renal 11β-HSD2 deficiency on developing hypertension by using kidney-specific
Hsd11b2
knockout (
Hsd11b2
Ksp-/-
; KS-KO) mice (
Hypertension
, in press) and have continued the analysis of the systemic effect of renal 11β-HSD2 deficiency.
Method:
Blood pressure (BP) and heart rate (HR) was measured by using 24h telemetry. Amiloride (25 mg/L) and hydrochlorothiazide (HCTZ, 300 mg/L) were administered through drinking water. Pellet containing MR antagonist spironolactone (MRA; 50 mg/KgBW/day) was administered subcutaneously. Corticosterone concentration was determined by ELISA. Data are presented as mean±SE.
Result:
Systolic and diastolic BPs of KS-KO mice were significantly higher, although the HR was lower, than those of WT mice: SBP, 142.4±1.0 vs 122.4±0.8 mmHg; DBP, 103.9±0.8 vs 94.4±0.8 mmHg; HR, 492.5±2.7 vs 555.4±2.4 (n=7). Mean BP was decreased to the level of WT mice by reducing dietary sodium content from 0.3 % to 0.01 %. Plasma [K
+
] was significantly lower in KS-KO mice: 2.9±0.2 vs 4.2±0.2 mEq/L (n=5). Renal membrane expressions of NCC, T53-phosphorylated NCC (pNCC), cleaved ENaCα and full-length ENaCα were upregulated in KS-KO mice. Correction of plasma [K
+
] of KS-KO mice by using high KCl diet or amiloride downregulated the renal membrane expression of pNCC and decreased the MBP to the level of WT mice as well as chronic HCTZ-treated KS-KO mice. Subcutaneous administration of MRA decreased MBP of KS-KO mice and the renal membrane expressions of pNCC and cleaved ENaCα. Diurnal variation of plasma corticosterone concentration was diminished in KS-KO mice and the urinary excretion of corticosterone was higher compared to that in WT mice.
Conclusion:
Renal 11β-HSD2 deficiency is sufficient in developing hypertension via MR activation induced by excessive corticosterone, the systemic effect of which are also suggested.
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Affiliation(s)
| | | | | | | | | | | | - Tatsuo Shimosawa
- Dept of Clinical Laboratory, International Univ of Health and Welfare, Sch of Medicine, Tokyo, Japan
| | - Johannes Loffing
- National Cntr of Competence in Rsch ’Kidney Control of Homeostasis’, Zurich, Switzerland
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14
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Ueda K, Nishimoto M, Hirohama D, Ayuzawa N, Kawarazaki W, Watanabe A, Shimosawa T, Loffing J, Zhang MZ, Marumo T, Fujita T. Renal Dysfunction Induced by Kidney-Specific Gene Deletion of Hsd11b2 as a Primary Cause of Salt-Dependent Hypertension. Hypertension 2017; 70:111-118. [PMID: 28559392 DOI: 10.1161/hypertensionaha.116.08966] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 03/31/2017] [Accepted: 04/10/2017] [Indexed: 01/21/2023]
Abstract
Genome-wide analysis of renal sodium-transporting system has identified specific variations of Mendelian hypertensive disorders, including HSD11B2 gene variants in apparent mineralocorticoid excess. However, these genetic variations in extrarenal tissue can be involved in developing hypertension, as demonstrated in former studies using global and brain-specific Hsd11b2 knockout rodents. To re-examine the importance of renal dysfunction on developing hypertension, we generated kidney-specific Hsd11b2 knockout mice. The knockout mice exhibited systemic hypertension, which was abolished by reducing salt intake, suggesting its salt-dependency. In addition, we detected an increase in renal membrane expressions of cleaved epithelial sodium channel-α and T53-phosphorylated Na+-Cl- cotransporter in the knockout mice. Acute intraperitoneal administration of amiloride-induced natriuresis and increased urinary sodium/potassium ratio more in the knockout mice compared with those in the wild-type control mice. Chronic administration of amiloride and high-KCl diet significantly decreased mean blood pressure in the knockout mice, which was accompanied with the correction of hypokalemia and the resultant decrease in Na+-Cl- cotransporter phosphorylation. Accordingly, a Na+-Cl- cotransporter blocker hydrochlorothiazide significantly decreased mean blood pressure in the knockout mice. Chronic administration of mineralocorticoid receptor antagonist spironolactone significantly decreased mean blood pressure of the knockout mice along with downregulation of cleaved epithelial sodium channel-α and phosphorylated Na+-Cl- cotransporter expression in the knockout kidney. Our data suggest that kidney-specific deficiency of 11β-HSD2 leads to salt-dependent hypertension, which is attributed to mineralocorticoid receptor-epithelial sodium channel-Na+-Cl- cotransporter activation in the kidney, and provides evidence that renal dysfunction is essential for developing the phenotype of apparent mineralocorticoid excess.
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Affiliation(s)
- Kohei Ueda
- From the Division of Clinical Epigenetics, Research Center of Advanced Science and Technology, The University of Tokyo, Japan (K.U., M.N., D.H., N.A., W.K., A.W., T.M., T.F.); Department of Clinical Laboratory, International University of Health and Welfare, School of Medicine, Tokyo, Japan (T.S.); CREST, Japan Agency for Medical Research and Development (AMED), Tokyo (T.S., T.M., T.F.); National Center of Competence in Research 'Kidney Control of Homeostasis', Zurich, Switzerland (J.L.); Institute of Anatomy, University of Zurich, Switzerland (J.L.); Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN (M.-Z.Z.); and Department of Nephrology and Endocrinology, National Defense Medical College, Saitama, Japan (A.W.).
| | - Mitsuhiro Nishimoto
- From the Division of Clinical Epigenetics, Research Center of Advanced Science and Technology, The University of Tokyo, Japan (K.U., M.N., D.H., N.A., W.K., A.W., T.M., T.F.); Department of Clinical Laboratory, International University of Health and Welfare, School of Medicine, Tokyo, Japan (T.S.); CREST, Japan Agency for Medical Research and Development (AMED), Tokyo (T.S., T.M., T.F.); National Center of Competence in Research 'Kidney Control of Homeostasis', Zurich, Switzerland (J.L.); Institute of Anatomy, University of Zurich, Switzerland (J.L.); Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN (M.-Z.Z.); and Department of Nephrology and Endocrinology, National Defense Medical College, Saitama, Japan (A.W.)
| | - Daigoro Hirohama
- From the Division of Clinical Epigenetics, Research Center of Advanced Science and Technology, The University of Tokyo, Japan (K.U., M.N., D.H., N.A., W.K., A.W., T.M., T.F.); Department of Clinical Laboratory, International University of Health and Welfare, School of Medicine, Tokyo, Japan (T.S.); CREST, Japan Agency for Medical Research and Development (AMED), Tokyo (T.S., T.M., T.F.); National Center of Competence in Research 'Kidney Control of Homeostasis', Zurich, Switzerland (J.L.); Institute of Anatomy, University of Zurich, Switzerland (J.L.); Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN (M.-Z.Z.); and Department of Nephrology and Endocrinology, National Defense Medical College, Saitama, Japan (A.W.)
| | - Nobuhiro Ayuzawa
- From the Division of Clinical Epigenetics, Research Center of Advanced Science and Technology, The University of Tokyo, Japan (K.U., M.N., D.H., N.A., W.K., A.W., T.M., T.F.); Department of Clinical Laboratory, International University of Health and Welfare, School of Medicine, Tokyo, Japan (T.S.); CREST, Japan Agency for Medical Research and Development (AMED), Tokyo (T.S., T.M., T.F.); National Center of Competence in Research 'Kidney Control of Homeostasis', Zurich, Switzerland (J.L.); Institute of Anatomy, University of Zurich, Switzerland (J.L.); Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN (M.-Z.Z.); and Department of Nephrology and Endocrinology, National Defense Medical College, Saitama, Japan (A.W.)
| | - Wakako Kawarazaki
- From the Division of Clinical Epigenetics, Research Center of Advanced Science and Technology, The University of Tokyo, Japan (K.U., M.N., D.H., N.A., W.K., A.W., T.M., T.F.); Department of Clinical Laboratory, International University of Health and Welfare, School of Medicine, Tokyo, Japan (T.S.); CREST, Japan Agency for Medical Research and Development (AMED), Tokyo (T.S., T.M., T.F.); National Center of Competence in Research 'Kidney Control of Homeostasis', Zurich, Switzerland (J.L.); Institute of Anatomy, University of Zurich, Switzerland (J.L.); Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN (M.-Z.Z.); and Department of Nephrology and Endocrinology, National Defense Medical College, Saitama, Japan (A.W.)
| | - Atsushi Watanabe
- From the Division of Clinical Epigenetics, Research Center of Advanced Science and Technology, The University of Tokyo, Japan (K.U., M.N., D.H., N.A., W.K., A.W., T.M., T.F.); Department of Clinical Laboratory, International University of Health and Welfare, School of Medicine, Tokyo, Japan (T.S.); CREST, Japan Agency for Medical Research and Development (AMED), Tokyo (T.S., T.M., T.F.); National Center of Competence in Research 'Kidney Control of Homeostasis', Zurich, Switzerland (J.L.); Institute of Anatomy, University of Zurich, Switzerland (J.L.); Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN (M.-Z.Z.); and Department of Nephrology and Endocrinology, National Defense Medical College, Saitama, Japan (A.W.)
| | - Tatsuo Shimosawa
- From the Division of Clinical Epigenetics, Research Center of Advanced Science and Technology, The University of Tokyo, Japan (K.U., M.N., D.H., N.A., W.K., A.W., T.M., T.F.); Department of Clinical Laboratory, International University of Health and Welfare, School of Medicine, Tokyo, Japan (T.S.); CREST, Japan Agency for Medical Research and Development (AMED), Tokyo (T.S., T.M., T.F.); National Center of Competence in Research 'Kidney Control of Homeostasis', Zurich, Switzerland (J.L.); Institute of Anatomy, University of Zurich, Switzerland (J.L.); Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN (M.-Z.Z.); and Department of Nephrology and Endocrinology, National Defense Medical College, Saitama, Japan (A.W.)
| | - Johannes Loffing
- From the Division of Clinical Epigenetics, Research Center of Advanced Science and Technology, The University of Tokyo, Japan (K.U., M.N., D.H., N.A., W.K., A.W., T.M., T.F.); Department of Clinical Laboratory, International University of Health and Welfare, School of Medicine, Tokyo, Japan (T.S.); CREST, Japan Agency for Medical Research and Development (AMED), Tokyo (T.S., T.M., T.F.); National Center of Competence in Research 'Kidney Control of Homeostasis', Zurich, Switzerland (J.L.); Institute of Anatomy, University of Zurich, Switzerland (J.L.); Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN (M.-Z.Z.); and Department of Nephrology and Endocrinology, National Defense Medical College, Saitama, Japan (A.W.)
| | - Ming-Zhi Zhang
- From the Division of Clinical Epigenetics, Research Center of Advanced Science and Technology, The University of Tokyo, Japan (K.U., M.N., D.H., N.A., W.K., A.W., T.M., T.F.); Department of Clinical Laboratory, International University of Health and Welfare, School of Medicine, Tokyo, Japan (T.S.); CREST, Japan Agency for Medical Research and Development (AMED), Tokyo (T.S., T.M., T.F.); National Center of Competence in Research 'Kidney Control of Homeostasis', Zurich, Switzerland (J.L.); Institute of Anatomy, University of Zurich, Switzerland (J.L.); Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN (M.-Z.Z.); and Department of Nephrology and Endocrinology, National Defense Medical College, Saitama, Japan (A.W.)
| | - Takeshi Marumo
- From the Division of Clinical Epigenetics, Research Center of Advanced Science and Technology, The University of Tokyo, Japan (K.U., M.N., D.H., N.A., W.K., A.W., T.M., T.F.); Department of Clinical Laboratory, International University of Health and Welfare, School of Medicine, Tokyo, Japan (T.S.); CREST, Japan Agency for Medical Research and Development (AMED), Tokyo (T.S., T.M., T.F.); National Center of Competence in Research 'Kidney Control of Homeostasis', Zurich, Switzerland (J.L.); Institute of Anatomy, University of Zurich, Switzerland (J.L.); Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN (M.-Z.Z.); and Department of Nephrology and Endocrinology, National Defense Medical College, Saitama, Japan (A.W.)
| | - Toshiro Fujita
- From the Division of Clinical Epigenetics, Research Center of Advanced Science and Technology, The University of Tokyo, Japan (K.U., M.N., D.H., N.A., W.K., A.W., T.M., T.F.); Department of Clinical Laboratory, International University of Health and Welfare, School of Medicine, Tokyo, Japan (T.S.); CREST, Japan Agency for Medical Research and Development (AMED), Tokyo (T.S., T.M., T.F.); National Center of Competence in Research 'Kidney Control of Homeostasis', Zurich, Switzerland (J.L.); Institute of Anatomy, University of Zurich, Switzerland (J.L.); Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN (M.-Z.Z.); and Department of Nephrology and Endocrinology, National Defense Medical College, Saitama, Japan (A.W.).
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15
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Abstract
Obese subjects often have hypertension and related cardiovascular and renal diseases, and this has become a serious worldwide health problem. In obese subjects, impaired renal-pressure natriuresis causes sodium retention, leading to the development of salt-sensitive hypertension. Physical compression of the kidneys by visceral fat and activation of the sympathetic nervous system, renin-angiotensin systems (RAS), and aldosterone/mineralocorticoid receptor (MR) system are involved in this mechanism. Obese subjects often exhibit hyperaldosteronism, with increased salt sensitivity of blood pressure (BP). Adipose tissue excretes aldosterone-releasing factors, thereby stimulating aldosterone secretion independently of the systemic RAS, and aldosterone/MR activation plays a key role in the development of hypertension and organ damage in obesity. In obese subjects, both salt sensitivity of BP, enhanced by obesity-related metabolic disorders including aldosterone excess, and increased dietary sodium intake are closely related to the incidence of hypertension. Some salt sensitivity-related gene variants affect the risk of obesity, and together with salt intake, its combination is possibly associated with the development of hypertension in obese subjects. With high salt levels common in modern diets, salt restriction and weight control are undoubtedly important. However, not only MR blockade but also new diagnostic modalities and therapies targeting and modifying genes that are related to salt sensitivity, obesity, or RAS regulation are expected to prevent obesity and obesity-related hypertension.
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Affiliation(s)
- Wakako Kawarazaki
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.
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16
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Ayuzawa N, Nagase M, Ueda K, Nishimoto M, Kawarazaki W, Marumo T, Aiba A, Sakurai T, Shindo T, Fujita T. Rac1-Mediated Activation of Mineralocorticoid Receptor in Pressure Overload–Induced Cardiac Injury. Hypertension 2016; 67:99-106. [DOI: 10.1161/hypertensionaha.115.06054] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 10/09/2015] [Indexed: 12/21/2022]
Affiliation(s)
- Nobuhiro Ayuzawa
- From the Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (N.A., K.U., M. Nishimoto, W.K., T.M., T.F.), and Laboratory of Animal Resources, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine (A.A.), The University of Tokyo, Tokyo, Japan; Department of Anatomy and Life Structure, Faculty of Medicine, Juntendo University, Tokyo, Japan (M. Nagase); CREST, Japan Science and Technology Agency, Tokyo, Japan (T.M., T.F.); and Department of
| | - Miki Nagase
- From the Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (N.A., K.U., M. Nishimoto, W.K., T.M., T.F.), and Laboratory of Animal Resources, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine (A.A.), The University of Tokyo, Tokyo, Japan; Department of Anatomy and Life Structure, Faculty of Medicine, Juntendo University, Tokyo, Japan (M. Nagase); CREST, Japan Science and Technology Agency, Tokyo, Japan (T.M., T.F.); and Department of
| | - Kohei Ueda
- From the Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (N.A., K.U., M. Nishimoto, W.K., T.M., T.F.), and Laboratory of Animal Resources, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine (A.A.), The University of Tokyo, Tokyo, Japan; Department of Anatomy and Life Structure, Faculty of Medicine, Juntendo University, Tokyo, Japan (M. Nagase); CREST, Japan Science and Technology Agency, Tokyo, Japan (T.M., T.F.); and Department of
| | - Mitsuhiro Nishimoto
- From the Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (N.A., K.U., M. Nishimoto, W.K., T.M., T.F.), and Laboratory of Animal Resources, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine (A.A.), The University of Tokyo, Tokyo, Japan; Department of Anatomy and Life Structure, Faculty of Medicine, Juntendo University, Tokyo, Japan (M. Nagase); CREST, Japan Science and Technology Agency, Tokyo, Japan (T.M., T.F.); and Department of
| | - Wakako Kawarazaki
- From the Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (N.A., K.U., M. Nishimoto, W.K., T.M., T.F.), and Laboratory of Animal Resources, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine (A.A.), The University of Tokyo, Tokyo, Japan; Department of Anatomy and Life Structure, Faculty of Medicine, Juntendo University, Tokyo, Japan (M. Nagase); CREST, Japan Science and Technology Agency, Tokyo, Japan (T.M., T.F.); and Department of
| | - Takeshi Marumo
- From the Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (N.A., K.U., M. Nishimoto, W.K., T.M., T.F.), and Laboratory of Animal Resources, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine (A.A.), The University of Tokyo, Tokyo, Japan; Department of Anatomy and Life Structure, Faculty of Medicine, Juntendo University, Tokyo, Japan (M. Nagase); CREST, Japan Science and Technology Agency, Tokyo, Japan (T.M., T.F.); and Department of
| | - Atsu Aiba
- From the Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (N.A., K.U., M. Nishimoto, W.K., T.M., T.F.), and Laboratory of Animal Resources, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine (A.A.), The University of Tokyo, Tokyo, Japan; Department of Anatomy and Life Structure, Faculty of Medicine, Juntendo University, Tokyo, Japan (M. Nagase); CREST, Japan Science and Technology Agency, Tokyo, Japan (T.M., T.F.); and Department of
| | - Takayuki Sakurai
- From the Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (N.A., K.U., M. Nishimoto, W.K., T.M., T.F.), and Laboratory of Animal Resources, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine (A.A.), The University of Tokyo, Tokyo, Japan; Department of Anatomy and Life Structure, Faculty of Medicine, Juntendo University, Tokyo, Japan (M. Nagase); CREST, Japan Science and Technology Agency, Tokyo, Japan (T.M., T.F.); and Department of
| | - Takayuki Shindo
- From the Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (N.A., K.U., M. Nishimoto, W.K., T.M., T.F.), and Laboratory of Animal Resources, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine (A.A.), The University of Tokyo, Tokyo, Japan; Department of Anatomy and Life Structure, Faculty of Medicine, Juntendo University, Tokyo, Japan (M. Nagase); CREST, Japan Science and Technology Agency, Tokyo, Japan (T.M., T.F.); and Department of
| | - Toshiro Fujita
- From the Division of Clinical Epigenetics, Research Center for Advanced Science and Technology (N.A., K.U., M. Nishimoto, W.K., T.M., T.F.), and Laboratory of Animal Resources, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine (A.A.), The University of Tokyo, Tokyo, Japan; Department of Anatomy and Life Structure, Faculty of Medicine, Juntendo University, Tokyo, Japan (M. Nagase); CREST, Japan Science and Technology Agency, Tokyo, Japan (T.M., T.F.); and Department of
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17
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Marumo T, Yagi S, Kawarazaki W, Nishimoto M, Ayuzawa N, Watanabe A, Ueda K, Hirahashi J, Hishikawa K, Sakurai H, Shiota K, Fujita T. Diabetes Induces Aberrant DNA Methylation in the Proximal Tubules of the Kidney. J Am Soc Nephrol 2015; 26:2388-97. [PMID: 25653098 DOI: 10.1681/asn.2014070665] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 11/26/2014] [Indexed: 01/07/2023] Open
Abstract
Epigenetic mechanisms may underlie the progression of diabetic kidney disease. Because the kidney is a heterogeneous organ with different cell types, we investigated DNA methylation status of the kidney in a cell type-specific manner. We first identified genes specifically demethylated in the normal proximal tubules obtained from control db/m mice, and next delineated the candidate disease-modifying genes bearing aberrant DNA methylation induced by diabetes using db/db mice. Genes involved in glucose metabolism, including Sglt2, Pck1, and G6pc, were selectively hypomethylated in the proximal tubules in control mice. Hnf4a, a transcription factor regulating transporters for reabsorption, was also selectively demethylated. In diabetic mice, aberrant hypomethylation of Agt, Abcc4, Cyp4a10, Glut5, and Met and hypermethylation of Kif20b, Cldn18, and Slco1a1 were observed. Time-dependent demethylation of Agt, a marker of diabetic kidney disease, was accompanied by histone modification changes. Furthermore, inhibition of DNA methyltransferase or histone deacetylase increased Agt mRNA in cultured human proximal tubular cells. Aberrant DNA methylation and concomitant changes in histone modifications and mRNA expression in the diabetic kidney were resistant to antidiabetic treatment with pioglitazone. These results suggest that an epigenetic switch involving aberrant DNA methylation causes persistent mRNA expression of select genes that may lead to phenotype changes of the proximal tubules in diabetic kidney disease.
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Affiliation(s)
- Takeshi Marumo
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, CREST, Japan Science and Technology Agency, Tokyo, Japan
| | - Shintaro Yagi
- Laboratory of Cellular Biochemistry, Department of Animal Resource Sciences/Veterinary Medical Sciences, and
| | - Wakako Kawarazaki
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology
| | - Mitsuhiro Nishimoto
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology
| | - Nobuhiro Ayuzawa
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology
| | - Atsushi Watanabe
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology
| | - Kohei Ueda
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology
| | - Junichi Hirahashi
- Apheresis and Dialysis Center, School of Medicine, Keio University, Tokyo, Japan; and
| | - Keiichi Hishikawa
- Department of Advanced Nephrology and Regenerative Medicine, The University of Tokyo, Tokyo, Japan
| | - Hiroyuki Sakurai
- Department of Pharmacology, School of Medicine, Kyorin University, Tokyo, Japan
| | - Kunio Shiota
- Laboratory of Cellular Biochemistry, Department of Animal Resource Sciences/Veterinary Medical Sciences, and
| | - Toshiro Fujita
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, CREST, Japan Science and Technology Agency, Tokyo, Japan;
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18
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Kawarazaki W, Fujita T. Aberrant Rac1-mineralocorticoid receptor pathways in salt-sensitive hypertension. Clin Exp Pharmacol Physiol 2014; 40:929-36. [PMID: 24111570 DOI: 10.1111/1440-1681.12177] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 09/11/2013] [Accepted: 09/17/2013] [Indexed: 12/17/2022]
Abstract
According to Guyton's model, impaired renal sodium excretion plays a key role in the increased salt sensitivity of blood pressure (BP). Several factors contribute to impaired renal sodium excretion, including the sympathetic nervous system, the renin-angiotensin system and aldosterone. Accumulating evidence suggests that abnormalities in aldosterone and its receptor (i.e. the mineralocorticoid receptor (MR)) are involved in the development of salt-sensitive (SS) hypertension. Patients with metabolic syndrome often exhibit hyperaldosteronism and are susceptible to SS hypertension. Aldosterone secretion from the adrenal glands is not suppressed in obese hypertensive rats fed a high-salt diet because of the abundant production of adipocyte-derived aldosterone-releasing factors, which are independent of the negative feedback regulation of aldosterone secretion by the renin-angiotensin-aldosterone system. Increased plasma aldosterone levels lead to SS hypertension via MR activation in the kidney. Renal MR activity is increased in Dahl salt-sensitive rats fed a high-salt diet, despite the appropriate suppression of plasma aldosterone levels. In this rat strain, activation of MR in the distal nephron causes salt-induced hypertension. This paradoxical response of the MR to salt loading can be attributed to activation of Rac1, a small GTPase. In the presence of aldosterone, activated Rac1 synergistically and directly activates MR in a ligand-independent manner. Thus, Rac1 activation in the kidney determines the salt sensitivity of BP. Together, the available evidence suggests that the aberrant Rac1-MR pathway plays a key role in the development of SS hypertension.
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Affiliation(s)
- Wakako Kawarazaki
- Division of Clinical Epigenetics, Research Center for Advanced Science and Technology=1, The University of Tokyo=1, Tokyo, Japan
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19
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Yoshida S, Ishizawa K, Ayuzawa N, Ueda K, Takeuchi M, Kawarazaki W, Fujita T, Nagase M. Local mineralocorticoid receptor activation and the role of Rac1 in obesity-related diabetic kidney disease. Nephron Clin Pract 2014; 126:16-24. [PMID: 24603367 DOI: 10.1159/000358758] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 01/14/2014] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND/AIMS Obesity and diabetes are intimately interrelated, and are independent risk factors for kidney disease. Overactivation of mineralocorticoid receptor (MR) is implicated in end organ damage of both pathologies. But the underlying mechanism of MR activation in kidney remains uncertain. We explored the involvement of Rac1, which we previously identified as a ligand-independent MR activator, in renal MR activation in vitro and in vivo. METHODS We evaluated the MR activity and Rac1 activity under high-glucose stimulation using luciferase reporter system and glutathione S-transferase pull-down assay in cultured mesangial cells. To elucidate the role of Rac1 in vivo, we employed KKA(y), a mouse model of obesity-related type 2 diabetes, which spontaneously developed massive albuminuria and distinct glomerular lesions accompanied by increased plasma aldosterone concentration. RESULTS High-glucose stimulation increased Rac1 activity and MR transcriptional activity in cultured mesangial cells. Overexpression of constitutively active Rac1 activated MR, and glucose-induced MR activation was suppressed by overexpression of dominant negative Rac1 or Rac inhibitor EHT1864. In KKA(y), renal Rac1 was activated, and nuclear MR was increased. EHT1864 treatment suppressed renal Rac1 and MR activity and mitigated renal pathology of KKA(y) without changing plasma aldosterone concentration. CONCLUSION Our results suggest that MR activation plays an important role in the nephropathy of KKA(y) mice, and that glucose-induced Rac1 activation, in addition to hyperaldosteronemia, contributes to their renal MR activation. Along with MR blockade, Rac inhibition may potentially be a preferred option in the treatment of nephropathy in obesity-related diabetic patients.
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Affiliation(s)
- Shigetaka Yoshida
- Department of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
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20
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Yoshida S, Ishizawa K, Ayuzawa N, Ueda K, Takeuchi M, Kawarazaki W, Fujita T, Nagase M. Renin inhibition ameliorates renal damage through prominent suppression of both angiotensin I and II in human renin angiotensinogen transgenic mice with high salt loading. Clin Exp Nephrol 2013; 18:593-9. [PMID: 24154707 DOI: 10.1007/s10157-013-0893-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 10/09/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND The renin-angiotensin-aldosterone system (RAAS) plays pivotal roles in the pathogenesis of chronic kidney disease (CKD) progression. Aliskiren, a direct renin inhibitor, inhibits the rate-limiting step of the RAAS without any alternative pathway. It is proven to reduce albuminuria in CKD patients treated with angiotensin blockade. However, there are few reports which evaluate the advantage of aliskiren as the first-line drug against CKD progression in RAAS-activated hypertensive patients. METHODS Tsukuba hypertensive mice (THM), double transgenic mice carrying both the human renin and human angiotensinogen genes, were fed a high-salt diet and treated with hydraladine, ramipril and aliskiren for 10 weeks. Blood pressure and urinary albumin excretion were measured every 2 weeks during the experimental period. We evaluated renal histological changes and gene expression. Plasma angiotensin concentration was measured to evaluate the RAAS inhibitory effect. RESULTS High-salt-loaded THM showed severe hypertension and renal injury. All antihypertensive drugs suppressed blood pressure and prevented renal disease progression. RAAS blockade showed a higher renoprotective effect than hydraladine despite an equivalent blood pressure lowering effect. Aliskiren exhibited even stronger renoprotection than ramipril. Plasma angiotensin concentration was increased in THM fed both normal salt and high salt. Hydraladine did not alter the plasma angiotensin concentration. Ramipril significantly decreased angiotensin II concentration. Aliskiren treatment almost completely suppressed angiotensin I and resulted in lower angiotensin II concentration than ramipril treatment. CONCLUSION Aliskiren prevents renal disease progression by suppressing both angiotensin I and II in RAAS-activated pathology. Our data suggest the application of a renin inhibitor for preventing kidney disease progression in CKD patients.
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Affiliation(s)
- Shigetaka Yoshida
- Department of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, 7-3-1 Hongo Bunkyo-ku, Tokyo, 113-8655, Japan,
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21
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Ayuzawa N, Nagase M, Ueda K, Ishizawa K, Takeuchi M, Kawarazaki W, Yoshida S, Fujita T. Abstract 69: Requirement of Rac1 in Pressure Overload-induced Cardiac Remodeling, and Role of Mineralocorticoid Receptor as a Downstream Pathway. Hypertension 2012. [DOI: 10.1161/hyp.60.suppl_1.a69] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A Rho family GTPase, Rac1, has emerged as an important molecule involved in cardiac remodeling. Some studies demonstrated the requirement of Rac1 in angiotensin II-induced cardiac hypertrophy and diabetic cardiomyopathy in association with generation of reactive oxygen species (ROS). However its role in pressure overload-induced cardiac remodeling is still unclear. On the other hand, we previously reported that Rac1 can activate mineralocorticoid receptor (MR) in cultured cardiomyocytes. Here we demonstrate the requirement of Rac1 in pressure-overload cardiac remodeling, and putative role of MR as a downstream pathway of Rac1. First, we performed sham or transverse aortic constriction (TAC) surgery in C57BL/6 mice, and examined the effect of Rac1 inhibitor (
NSC23766
) and MR blocker (eplerenone). After 7 weeks, TAC caused severe hypertrophy and dysfunction of left ventricle with significant increase in active form of Rac1. In addition, the amount of MR protein in nuclear fraction, and the expression of some target genes of MR (including serpina3n and serpine-1) in left ventricle were also increased by TAC.
NSC23766
significantly reduced the TAC-induced activation of Rac1, and both
NSC23766
and eplerenone attenuated cardiac hypertrophy and dysfunction, along with inhibition of MR signaling. Furthermore, TAC significantly increased ROS production in left ventricle, which was also attenuated by both of the pharmacological interventions. We next generated cardiomyocyte-specific heterozygous Rac1-deficient mice (Rac1
CM +/−
) and littermate wild-type mice (WT), and performed Sham or TAC surgery. The TAC-induced hypertrophy and dysfunction of left ventricle were significantly suppressed in Rac1
CM +/−
compared with WT (heart/body weight ratio: 6.4 ± 0.86 vs 10.8 ± 0.81 mg/g, ejection fraction 54.1 ± 6.5 vs 33.3 ± 7.3 %, p < 0.05), with inhibition of Rac1 activation. Nuclear translocation of MR protein and increases in expression of the target genes of MR were also significantly attenuated in Rac1
CM +/−
compared with WT. These results indicate that Rac1 plays an essential role in the maladaptive cardiac hypertrophy induced by pressure overload, and that MR is an important downstream pathway of Rac1 in heart.
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Affiliation(s)
| | - Miki Nagase
- Univ of Tokyo Graduate Sch of Medicine, Tokyo, Japan
| | - Kohei Ueda
- Univ of Tokyo Graduate Sch of Medicine, Tokyo, Japan
| | | | - Maki Takeuchi
- Univ of Tokyo Graduate Sch of Medicine, Tokyo, Japan
| | - Wakako Kawarazaki
- Rsch Cntr for Advanced Science and Technology, Univ of Tokyo, Tokyo, Japan
| | | | - Toshiro Fujita
- Rsch Cntr for Advanced Science and Technology, Univ of Tokyo, Tokyo, Japan
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Kawarazaki W, Nagase M, Yoshida S, Takeuchi M, Ishizawa K, Ayuzawa N, Ueda K, Fujita T. Angiotensin II- and salt-induced kidney injury through Rac1-mediated mineralocorticoid receptor activation. J Am Soc Nephrol 2012; 23:997-1007. [PMID: 22440899 DOI: 10.1681/asn.2011070734] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Experiments with hyperaldosteronemic animals suggest that, despite lowering plasma aldosterone, salt worsens renal injury by paradoxical activation of the mineralocorticoid receptor (MR). Salt and aldosterone synergistically contribute to renal impairment through Rac1-mediated activation of the MR, but whether angiotensin II also promotes renal injury through this mechanism is unknown. Here, we placed angiotensin II-overproducing double transgenic Tsukuba hypertensive mice on a low- or high-salt intake for 6 weeks and treated some animals with adrenalectomy, the MR antagonist eplerenone, the Rac inhibitor EHT1864, or hydralazine. High-salt intake, but not low-salt intake, led to hypertension and prominent kidney injury. Adrenalectomy prevented angiotensin II/salt-induced nephropathy in mice receiving high-salt intake, which was recapitulated by aldosterone supplementation, suggesting the involvement of aldosterone/MR signaling. Plasma aldosterone levels, however, were lower in high- than low-salt conditions. Instead, angiotensin II/salt-evoked MR activation associated with Rac1 activation and was not dependent on plasma aldosterone level. Both EHT1864 and eplerenone repressed the augmented MR signaling and mitigated kidney injury with partial but significant reduction in BP with high-salt intake. Hydralazine similarly reduced BP, but it neither suppressed the Rac1-MR pathway nor ameliorated the nephropathy. Taken together, these results show that angiotensin II and salt accelerate kidney injury through Rac1-mediated MR activation. Rac inhibition may be a promising strategy for the treatment of CKD.
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Affiliation(s)
- Wakako Kawarazaki
- Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
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Nagase M, Ayuzawa N, Kawarazaki W, Ishizawa K, Ueda K, Yoshida S, Fujita T. Oxidative Stress Causes Mineralocorticoid Receptor Activation in Rat Cardiomyocytes. Hypertension 2012; 59:500-6. [DOI: 10.1161/hypertensionaha.111.185520] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Miki Nagase
- From the Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Nobuhiro Ayuzawa
- From the Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Wakako Kawarazaki
- From the Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Kenichi Ishizawa
- From the Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Kohei Ueda
- From the Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Shigetaka Yoshida
- From the Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Toshiro Fujita
- From the Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
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Shibata S, Mu S, Kawarazaki H, Muraoka K, Ishizawa KI, Yoshida S, Kawarazaki W, Takeuchi M, Ayuzawa N, Miyoshi J, Takai Y, Ishikawa A, Shimosawa T, Ando K, Nagase M, Fujita T. Rac1 GTPase in rodent kidneys is essential for salt-sensitive hypertension via a mineralocorticoid receptor-dependent pathway. J Clin Invest 2011; 121:3233-43. [PMID: 21765214 DOI: 10.1172/jci43124] [Citation(s) in RCA: 174] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 06/01/2011] [Indexed: 12/16/2022] Open
Abstract
Hypertension is a leading contributor to cardiovascular mortality worldwide. Despite this, its underlying mechanism(s) and the role of excess salt in cardiorenal dysfunction are unclear. Previously, we have identified cross-talk between mineralocorticoid receptor (MR), a nuclear transcription factor regulated by the steroid aldosterone, and the small GTPase Rac1, which is implicated in proteinuric kidney disease. We here show that high-salt loading activates Rac1 in the kidneys in rodent models of salt-sensitive hypertension, leading to blood pressure elevation and renal injury via an MR-dependent pathway. We found that a high-salt diet caused renal Rac1 upregulation in salt-sensitive Dahl (Dahl-S) rats and downregulation in salt-insensitive Dahl (Dahl-R) rats. Despite a reduction of serum aldosterone levels, salt-loaded Dahl-S rats showed increased MR signaling in the kidneys, and Rac1 inhibition prevented hypertension and renal damage with MR repression. We further demonstrated in aldosterone-infused rats as well as adrenalectomized Dahl-S rats with aldosterone supplementation that salt-induced Rac1 and aldosterone acted interdependently to cause MR overactivity and hypertension. Finally, we confirmed the key role of Rac1 in modulating salt susceptibility in mice lacking Rho GDP-dissociation inhibitor α. Therefore, our data identify Rac1 as a determinant of salt sensitivity and provide insights into the mechanism of salt-induced hypertension and kidney injury.
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Affiliation(s)
- Shigeru Shibata
- Department of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
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25
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Shibata S, Nagase M, Yoshida S, Kawarazaki W, Kurihara H, Tanaka H, Miyoshi J, Takai Y, Fujita T. Modification of mineralocorticoid receptor function by Rac1 GTPase: implication in proteinuric kidney disease. Nat Med 2008; 14:1370-6. [PMID: 19029984 DOI: 10.1038/nm.1879] [Citation(s) in RCA: 338] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 09/22/2008] [Indexed: 11/09/2022]
Abstract
Blockade of mineralocorticoid receptor has been shown to improve the clinical outcomes of proteinuric kidney diseases. However, little is known about the regulation of mineralocorticoid receptor-dependent transcriptional activity in renal disease. Here we identify a new role for Rac1, a member of the Rho family GTPases, as a potent activator of mineralocorticoid receptor signal transduction both in vitro and in vivo. Transient transfection assays in HEK 293 cells revealed that constitutively active Rac1 (CA-Rac1) enhanced mineralocorticoid receptor-dependent reporter activity, which was accompanied by increased nuclear translocation of mineralocorticoid receptor. CA-Rac1 facilitated mineralocorticoid receptor nuclear accumulation also in podocytes via p21-activated kinase phosphorylation. In mice lacking Rho GDP-dissociation inhibitor-alpha (Arhgdia(-/-) mice), renal abnormalities, including heavy albuminuria and podocyte damage, were associated with increased Rac1 (but not RhoA) and mineralocorticoid receptor signaling in the kidney, without alteration in systemic aldosterone status. Pharmacological intervention with a Rac-specific small-molecule inhibitor diminished mineralocorticoid receptor overactivity and renal damage in this model. Furthermore, albuminuria and histological changes in Arhgdia(-/-) mice were suppressed by mineralocorticoid receptor blockade, confirming the pathological role of Rac1-mineralocorticoid receptor interaction. Our results provide evidence that signaling cross-talk between Rac1 and mineralocorticoid receptor modulates mineralocorticoid receptor activity and identify Rac1 as a therapeutic target for chronic kidney disease.
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Kawarazaki H, Shibagaki Y, Shimizu H, Kawarazaki W, Ito N, Ishikawa A, Fukumoto S, Fujita T. Persistent high level of fibroblast growth factor 23 as a cause of post-renal transplant hypophosphatemia. Clin Exp Nephrol 2007; 11:255-257. [PMID: 17891358 DOI: 10.1007/s10157-007-0489-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2007] [Accepted: 06/28/2007] [Indexed: 12/19/2022]
Abstract
Post-transplant hypophosphatemia is a highly prevalent problem, and fibroblast growth factor 23, a newly discovered phosphatonin, has recently been reported to be involved in its pathogenesis. We report a 52-year-old Japanese woman who received a living-related kidney transplant and showed severe hypophosphatemia immediately after transplantation. We suspected that fibroblast growth factor 23 was the main cause of this hypophosphatemia and investigated its levels longitudinally after the transplantation. The patient showed persistently high levels of fibroblast growth factor 23, with suppressed 1,25-dihydroxyvitamin D and parathyroid hormone. She recovered from the hypophosphatemia when fibroblast growth factor returned to its reference level half a year after the transplantation. We conclude that a persistently high level of fibroblast growth factor 23 is an important cause of post-transplant hypophosphatemia, other than hyperparathyroidism, a previously noted cause.
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Affiliation(s)
- Hiroo Kawarazaki
- Department of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
| | - Yugo Shibagaki
- Department of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Hideki Shimizu
- Department of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Wakako Kawarazaki
- Department of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Nobuaki Ito
- Department of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Akira Ishikawa
- Department of Urology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Seiji Fukumoto
- Department of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Toshiro Fujita
- Department of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
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27
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Kawarazaki H, Ishibashi Y, Kawarazaki W, Shimizu H, Takara Y, Kume H, Sasahira N, Kaname S, Fujita T. Successful management of catheter obstruction by endoscopic naso-pancreatic drainage tube. Perit Dial Int 2007; 27:467. [PMID: 17602161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023] Open
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28
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Shimizu H, Ishibashi Y, Kumagai T, Kawarazaki H, Kawarazaki W, Kaname S, Fujita T. Successful reinstitution of peritoneal dialysis after gastric resection: a case report. Perit Dial Int 2006; 26:509-10. [PMID: 16881351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023] Open
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29
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Shimizu H, Ishibashi Y, Kumagai T, Kawarazaki H, Kawarazaki W, Kaname S, Fujita T. Successful Reinstitution of Peritoneal Dialysis after Gastric Resection: A Case Report. Perit Dial Int 2006. [DOI: 10.1177/089686080602600420] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- H. Shimizu
- Division of Total Renal Care Medicine University of Tokyo School of Medicine Tokyo, Japan
- Department of Nephrology and Endocrinology University of Tokyo School of Medicine Tokyo, Japan
| | - Y. Ishibashi
- Division of Total Renal Care Medicine University of Tokyo School of Medicine Tokyo, Japan
- Department of Nephrology and Endocrinology University of Tokyo School of Medicine Tokyo, Japan
| | - T. Kumagai
- Division of Total Renal Care Medicine University of Tokyo School of Medicine Tokyo, Japan
- Department of Nephrology and Endocrinology University of Tokyo School of Medicine Tokyo, Japan
| | - H. Kawarazaki
- Division of Total Renal Care Medicine University of Tokyo School of Medicine Tokyo, Japan
- Department of Nephrology and Endocrinology University of Tokyo School of Medicine Tokyo, Japan
| | - W. Kawarazaki
- Division of Total Renal Care Medicine University of Tokyo School of Medicine Tokyo, Japan
- Department of Nephrology and Endocrinology University of Tokyo School of Medicine Tokyo, Japan
| | - S. Kaname
- Division of Total Renal Care Medicine University of Tokyo School of Medicine Tokyo, Japan
- Department of Nephrology and Endocrinology University of Tokyo School of Medicine Tokyo, Japan
| | - T. Fujita
- Department of Nephrology and Endocrinology University of Tokyo School of Medicine Tokyo, Japan
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