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Taguchi S, Azushima K, Yamaji T, Suzuki T, Abe E, Tanaka S, Hirota K, Tsukamoto S, Morita R, Kobayashi R, Kinguchi S, Yamashita A, Wakui H, Tamura K. Angiotensin II type 1 receptor-associated protein deletion combined with angiotensin II stimulation accelerates the development of diabetic kidney disease in mice on a C57BL/6 strain. Hypertens Res 2024; 47:55-66. [PMID: 37957242 DOI: 10.1038/s41440-023-01496-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/09/2023] [Accepted: 10/20/2023] [Indexed: 11/15/2023]
Abstract
The progress in the research field of diabetic kidney disease (DKD) has been disturbed by the lack of reliable animal models. Angiotensin II (Ang II) type 1 receptor (AT1R)-associated protein (ATRAP) promotes internalization of AT1R and selectively inhibits pathological AT1R signaling. In this study, we investigated whether overactivation of the renin-angiotensin system (RAS) through a combination of ATRAP deletion with Ang II stimulation developed a progressive DKD model in C57BL/6 mice, which are resistant to the development of kidney injury. Eight-week-old male systemic ATRAP-knockout mice on the C57BL/6 strain (KO) and their littermate wild-type mice (Ctrl) were divided into five groups: 1) Ctrl, 2) Ctrl-streptozotocin (STZ), 3) KO-STZ, 4) Ctrl-STZ-Ang II, and 5) KO-STZ-Ang II. Ang II was administered for 6 weeks from 4 weeks after STZ administration. At 10 weeks after STZ administration, mice were euthanized to evaluate kidney injuries. Neither ATRAP deletion alone nor Ang II stimulation alone developed a progressive DKD model in STZ-induced diabetic C57BL/6 mice. However, a combination of ATRAP deletion with Ang II stimulation accelerated the development of DKD as manifested by overt albuminuria, glomerular hypertrophy, podocyte loss, mesangial expansion, kidney interstitial fibrosis and functional insufficiency, concomitant with increased angiotensinogen and AT1R expression in the kidneys. In STZ-induced diabetic C57BL/6 mice that are resistant to the development of kidney injury, the combination of ATRAP deletion and Ang II stimulation accelerates the development of DKD, which may be associated with intrarenal RAS overactivation.
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Affiliation(s)
- Shinya Taguchi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kengo Azushima
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
| | - Takahiro Yamaji
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Toru Suzuki
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Eriko Abe
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Shohei Tanaka
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Keigo Hirota
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Shunichiro Tsukamoto
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Ryutaro Morita
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Ryu Kobayashi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Sho Kinguchi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Akio Yamashita
- Department of Investigative Medicine, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Hiromichi Wakui
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
| | - Kouichi Tamura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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Tsukamoto S, Suzuki T, Wakui H, Uehara T, Ichikawa J, Okuda H, Haruhara K, Azushima K, Abe E, Tanaka S, Taguchi S, Hirota K, Kinguchi S, Yamashita A, Tamura T, Tamura K. Angiotensin II type 1 receptor-associated protein in immune cells: a possible key factor in the pathogenesis of visceral obesity. Metabolism 2023; 149:155706. [PMID: 37856903 DOI: 10.1016/j.metabol.2023.155706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 09/19/2023] [Accepted: 10/09/2023] [Indexed: 10/21/2023]
Abstract
BACKGROUND AND AIM Dysregulation of angiotensin II type 1 receptor-associated protein (ATRAP) expression in cardiovascular, kidney, and adipose tissues is involved in the pathology of hypertension, cardiac hypertrophy, atherosclerosis, kidney injury, and metabolic disorders. Furthermore, ATRAP is highly expressed in bone marrow-derived immune cells; however, the functional role of immune cell ATRAP in obesity-related pathology remains unclear. Thus, we sought to identify the pathophysiological significance of immune cell ATRAP in the development of visceral obesity and obesity-related metabolic disorders using a mouse model of diet-induced obesity. METHODS Initially, we examined the effect of high-fat diet (HFD)-induced obesity on the expression of immune cell ATRAP in wild-type mice. Subsequently, we conducted bone marrow transplantation to generate two types of chimeric mice: bone marrow wild-type chimeric (BM-WT) and bone marrow ATRAP knockout chimeric (BM-KO) mice. These chimeric mice were provided an HFD to induce visceral obesity, and then the effects of immune cell ATRAP deficiency on physiological parameters and adipose tissue in the chimeric mice were investigated. RESULTS In wild-type mice, body weight increase by HFD was associated with increased expression of immune cell ATRAP. In the bone marrow transplantation experiments, BM-KO mice exhibited amelioration of HFD-induced weight gain and visceral fat expansion with small adipocytes compared BM-WT mice. In addition, BM-KO mice on the HFD showed significant improvements in white adipose tissue metabolism, inflammation, glucose tolerance, and insulin resistance, compared with BM-WT mice on the HFD. Detailed analysis of white adipose tissue revealed significant suppression of HFD-induced activation of transforming growth factor-beta signaling, a key contributor to visceral obesity, via amelioration of CD206+ macrophage accumulation in the adipose tissue of BM-KO mice. This finding suggests a relevant mechanism for the anti-obesity phenotype in BM-KO mice on the HFD. Finally, transcriptome analysis of monocytes indicated the possibility of genetic changes, such as the enhancement of interferon-γ response at the monocyte level, affecting macrophage differentiation in BM-KO mice. CONCLUSION Collectively, our results indicate that ATRAP in bone marrow-derived immune cells plays a role in the pathogenesis of visceral obesity. The regulation of ATRAP expression in immune cells may be a key factor against visceral adipose obesity with metabolic disorders.
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Affiliation(s)
- Shunichiro Tsukamoto
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Toru Suzuki
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Hiromichi Wakui
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
| | - Tatsuki Uehara
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Juri Ichikawa
- Department of Immunology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Hiroshi Okuda
- Department of Immunology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Kotaro Haruhara
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kengo Azushima
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Eriko Abe
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Shohei Tanaka
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Shinya Taguchi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Keigo Hirota
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Sho Kinguchi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Akio Yamashita
- Department of Investigative Medicine Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Tomohiko Tamura
- Department of Immunology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan; Advanced Medical Research Center, Yokohama City University, Japan
| | - Kouichi Tamura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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Hirota K, Yamashita A, Abe E, Yamaji T, Azushima K, Tanaka S, Taguchi S, Tsukamoto S, Wakui H, Tamura K. miR-125a-5p/miR-125b-5p contributes to pathological activation of angiotensin II-AT1R in mouse distal convoluted tubule cells by the suppression of Atrap. J Biol Chem 2023; 299:105478. [PMID: 37981211 PMCID: PMC10755798 DOI: 10.1016/j.jbc.2023.105478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/06/2023] [Accepted: 11/10/2023] [Indexed: 11/21/2023] Open
Abstract
The renin-angiotensin system plays a crucial role in the regulation of blood pressure. Activation of the angiotensin II (Ang II)-Ang II type 1 receptor (AT1R) signaling pathway contributes to the pathogenesis of hypertension and subsequent organ damage. AT1R-associated protein (ATRAP) has been identified as an endogenous inhibitory protein of the AT1R pathological activation. We have shown that mouse Atrap (Atrap) represses various Ang II-AT1R-mediated pathologies, including hypertension in mice. The expression of human ATRAP (ATRAP)/Atrap can be altered in various pathological states in humans and mice, such as Ang II stimulation and serum starvation. However, the regulatory mechanisms of ATRAP/Atrap are not yet fully elucidated. miRNAs are 21 to 23 nucleotides of small RNAs that post-transcriptionally repress gene expression. Single miRNA can act on hundreds of target mRNAs, and numerous miRNAs have been identified as the Ang II-AT1R signaling-associated disease phenotype modulator, but nothing is known about the regulation of ATRAP/Atrap. In the present study, we identified miR-125a-5p/miR-125b-5p as the evolutionarily conserved miRNAs that potentially act on ATRAP/Atrap mRNA. Further analysis revealed that miR-125a-5p/miR-125b-5p can directly repress both ATRAP and Atrap. In addition, the inhibition of miR-125a-5p/miR-125b-5p resulted in the suppression of the Ang II-AT1R signaling in mouse distal convoluted tubule cells. Taken together, miR-125a-5p/miR-125b-5p activates Ang II-AT1R signaling by the suppression of ATRAP/Atrap. Our results provide new insights into the potential approaches for achieving the organ-protective effects by the repression of the miR-125 family associated with the enhancement of ATRAP/Atrap expression.
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Affiliation(s)
- Keigo Hirota
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Akio Yamashita
- Department of Investigative Medicine, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
| | - Eriko Abe
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Takahiro Yamaji
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kengo Azushima
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Shohei Tanaka
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Shinya Taguchi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Shunichiro Tsukamoto
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Hiromichi Wakui
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kouichi Tamura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
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Murase S, Sakitani N, Maekawa T, Yoshino D, Takano K, Konno A, Hirai H, Saito T, Tanaka S, Shinohara K, Kishi T, Yoshikawa Y, Sakai T, Ayaori M, Inanami H, Tomiyasu K, Takashima A, Ogata T, Tsuchimochi H, Sato S, Saito S, Yoshino K, Matsuura Y, Funamoto K, Ochi H, Shinohara M, Nagao M, Sawada Y. Interstitial-fluid shear stresses induced by vertically oscillating head motion lower blood pressure in hypertensive rats and humans. Nat Biomed Eng 2023; 7:1350-1373. [PMID: 37414976 PMCID: PMC10651490 DOI: 10.1038/s41551-023-01061-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 05/27/2023] [Indexed: 07/08/2023]
Abstract
The mechanisms by which physical exercise benefits brain functions are not fully understood. Here, we show that vertically oscillating head motions mimicking mechanical accelerations experienced during fast walking, light jogging or treadmill running at a moderate velocity reduce the blood pressure of rats and human adults with hypertension. In hypertensive rats, shear stresses of less than 1 Pa resulting from interstitial-fluid flow induced by such passive head motions reduced the expression of the angiotensin II type-1 receptor in astrocytes in the rostral ventrolateral medulla, and the resulting antihypertensive effects were abrogated by hydrogel introduction that inhibited interstitial-fluid movement in the medulla. Our findings suggest that oscillatory mechanical interventions could be used to elicit antihypertensive effects.
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Affiliation(s)
- Shuhei Murase
- Department of Rehabilitation for Motor Functions, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
- Department of Orthopaedic Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Naoyoshi Sakitani
- Department of Rehabilitation for Motor Functions, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
- Department of Cell Biology, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Takahiro Maekawa
- Department of Rehabilitation for Motor Functions, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
| | - Daisuke Yoshino
- Division of Advanced Applied Physics, Institute of Engineering, Tokyo University of Agriculture and Technology, Koganei, Japan
| | - Kouji Takano
- Department of Rehabilitation for Brain Functions, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
| | - Ayumu Konno
- Department of Neurophysiology & Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Hirokazu Hirai
- Department of Neurophysiology & Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Taku Saito
- Department of Orthopaedic Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Sakae Tanaka
- Department of Orthopaedic Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Keisuke Shinohara
- Department of Cardiovascular Medicine, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Takuya Kishi
- Department of Cardiology, Graduate School of Medicine, International University of Health and Welfare, Okawa, Japan
| | - Yuki Yoshikawa
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Takamasa Sakai
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | | | - Hirohiko Inanami
- Inanami Spine & Joint Hospital/Iwai Orthopaedic Medical Hospital, Iwai Medical Foundation, Tokyo, Japan
| | - Koji Tomiyasu
- Center of Sports Science and Health Promotion, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
| | - Atsushi Takashima
- Department of Assistive Technology, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
| | - Toru Ogata
- Department of Rehabilitation for Motor Functions, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
- Department of Rehabilitation Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hirotsugu Tsuchimochi
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Shinya Sato
- Department of Advanced Medical Technologies, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Shigeyoshi Saito
- Department of Medical Physics and Engineering, Division of Health Sciences, Osaka University Graduate School of Medicine, Suita, Japan
| | - Kohzoh Yoshino
- School of Biological and Environmental Sciences, Kwansei Gakuin University, Sanda, Japan
| | - Yuiko Matsuura
- Department of Health and Sports, Niigata University of Health and Welfare, Niigata, Japan
| | | | - Hiroki Ochi
- Department of Rehabilitation for Motor Functions, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
| | - Masahiro Shinohara
- Department of Rehabilitation for Motor Functions, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
| | - Motoshi Nagao
- Department of Rehabilitation for Motor Functions, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan
| | - Yasuhiro Sawada
- Department of Rehabilitation for Motor Functions, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan.
- Department of Orthopaedic Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
- Department of Cell Biology, National Cerebral and Cardiovascular Center, Suita, Japan.
- Division of Advanced Applied Physics, Institute of Engineering, Tokyo University of Agriculture and Technology, Koganei, Japan.
- Department of Clinical Research, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan.
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Tanaka S, Wakui H, Azushima K, Tsukamoto S, Yamaji T, Urate S, Suzuki T, Abe E, Taguchi S, Yamada T, Kobayashi R, Kanaoka T, Kamimura D, Kinguchi S, Takiguchi M, Funakoshi K, Yamashita A, Ishigami T, Tamura K. Effects of a High-Protein Diet on Kidney Injury under Conditions of Non-CKD or CKD in Mice. Int J Mol Sci 2023; 24:ijms24097778. [PMID: 37175483 PMCID: PMC10177820 DOI: 10.3390/ijms24097778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/12/2023] [Accepted: 04/13/2023] [Indexed: 05/15/2023] Open
Abstract
Considering the prevalence of obesity and global aging, the consumption of a high-protein diet (HPD) may be advantageous. However, an HPD aggravates kidney dysfunction in patients with chronic kidney disease (CKD). Moreover, the effects of an HPD on kidney function in healthy individuals are controversial. In this study, we employed a remnant kidney mouse model as a CKD model and aimed to evaluate the effects of an HPD on kidney injury under conditions of non-CKD and CKD. Mice were divided into four groups: a sham surgery (sham) + normal diet (ND) group, a sham + HPD group, a 5/6 nephrectomy (Nx) + ND group and a 5/6 Nx + HPD group. Blood pressure, kidney function and kidney tissue injury were compared after 12 weeks of diet loading among the four groups. The 5/6 Nx groups displayed blood pressure elevation, kidney function decline, glomerular injury and tubular injury compared with the sham groups. Furthermore, an HPD exacerbated glomerular injury only in the 5/6 Nx group; however, an HPD did not cause kidney injury in the sham group. Clinical application of these results suggests that patients with CKD should follow a protein-restricted diet to prevent the exacerbation of kidney injury, while healthy individuals can maintain an HPD without worrying about the adverse effects.
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Affiliation(s)
- Shohei Tanaka
- Department of Medical Science and Cardiorenal Medicine, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Hiromichi Wakui
- Department of Medical Science and Cardiorenal Medicine, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Kengo Azushima
- Department of Medical Science and Cardiorenal Medicine, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Shunichiro Tsukamoto
- Department of Medical Science and Cardiorenal Medicine, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Takahiro Yamaji
- Department of Medical Science and Cardiorenal Medicine, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Shingo Urate
- Department of Medical Science and Cardiorenal Medicine, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Toru Suzuki
- Department of Medical Science and Cardiorenal Medicine, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Eriko Abe
- Department of Medical Science and Cardiorenal Medicine, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Shinya Taguchi
- Department of Medical Science and Cardiorenal Medicine, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Takayuki Yamada
- Department of Medical Science and Cardiorenal Medicine, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh, 3550 Terrace Street, Pittsburgh, PA 15261, USA
| | - Ryu Kobayashi
- Department of Medical Science and Cardiorenal Medicine, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Tomohiko Kanaoka
- Department of Medical Science and Cardiorenal Medicine, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Daisuke Kamimura
- Department of Medical Science and Cardiorenal Medicine, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Sho Kinguchi
- Department of Medical Science and Cardiorenal Medicine, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Masahito Takiguchi
- Department of Neuroanatomy, School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Kengo Funakoshi
- Department of Neuroanatomy, School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Akio Yamashita
- Department of Investigative Medicine, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishiharacho, Okinawa 903-0215, Japan
| | - Tomoaki Ishigami
- Department of Medical Science and Cardiorenal Medicine, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Kouichi Tamura
- Department of Medical Science and Cardiorenal Medicine, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
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Ohara H, Nabika T. Genetic Modifications to Alter Blood Pressure Level. Biomedicines 2022; 10:biomedicines10081855. [PMID: 36009402 PMCID: PMC9405136 DOI: 10.3390/biomedicines10081855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/27/2022] [Accepted: 07/29/2022] [Indexed: 12/04/2022] Open
Abstract
Genetic manipulation is one of the indispensable techniques to examine gene functions both in vitro and in vivo. In particular, cardiovascular phenotypes such as blood pressure cannot be evaluated in vitro system, necessitating the creation of transgenic or gene-targeted knock-out and knock-in experimental animals to understand the pathophysiological roles of specific genes on the disease conditions. Although genome-wide association studies (GWAS) in various human populations have identified multiple genetic variations associated with increased risk for hypertension and/or its complications, the causal links remain unresolved. Genome-editing technologies can be applied to many different types of cells and organisms for creation of knock-out/knock-in models. In the post-GWAS era, it may be more worthwhile to validate pathophysiological implications of the risk variants and/or candidate genes by creating genome-edited organisms.
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7
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Lay A TRAP for myeloid cell response in diabetic kidney disease. Kidney Int 2022; 101:872-874. [DOI: 10.1016/j.kint.2022.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 02/02/2022] [Indexed: 11/21/2022]
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8
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Ilatovskaya DV, Levchenko V, Winsor K, Blass GR, Spires DR, Sarsenova E, Polina I, Zietara A, Paterson M, Kriegel AJ, Staruschenko A. Effects of elevation of ANP and its deficiency on cardiorenal function. JCI Insight 2022; 7:148682. [PMID: 35380994 PMCID: PMC9090260 DOI: 10.1172/jci.insight.148682] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 03/30/2022] [Indexed: 11/17/2022] Open
Abstract
Atrial natriuretic peptide (ANP), encoded by Nppa, is a vasodilatory hormone that promotes salt excretion. Genome-wide association studies identified Nppa as a causative factor of blood pressure development, and in humans, ANP levels were suggested as an indicator of salt sensitivity. This study aimed to provide insights into the effects of ANP on cardiorenal function in salt-sensitive hypertension. To address this question, hypertension was induced in SSNPPA-/- (knockout of Nppa in the Dahl Salt-Sensitive (SS) rat background) or SSWT (wild type Dahl SS) rats by a high salt diet challenge (HS, 4% NaCl for 21 days). Chronic infusion of ANP in SSWT rats attenuated the increase in blood pressure and cardiorenal damage. Overall, SSNPPA-/- strain demonstrated higher blood pressure and intensified cardiac fibrosis (with no changes in ejection fraction) compared to SSWT rats. Furthermore, SSNPPA-/- rats exhibited kidney hypertrophy and higher glomerular injury scores, reduced diuresis, and lower sodium and chloride excretion than SSWT when fed a HS diet. Additionally, the activity of epithelial Na+ channel (ENaC) was found to be increased in the collecting ducts of the SSNPPA-/- rats. Taken together, these data show promise for the therapeutic benefits of ANP and ANP-increasing drugs for treating salt-sensitive hypertension.
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Affiliation(s)
- Daria V Ilatovskaya
- Department of Physiology, Medical College of Georgia, Augusta, United States of America
| | - Vladislav Levchenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, United States of America
| | - Kristen Winsor
- Department of Physiology, Medical College of Wisconsin, Milwaukee, United States of America
| | - Gregory R Blass
- Department of Physiology, Medical College of Wisconsin, Milwaukee, United States of America
| | - Denisha R Spires
- Department of Physiology, Medical College of Georgia, Augusta, United States of America
| | - Elizaveta Sarsenova
- Department of Medicine, Medical University of South Carolina, Charleston, United States of America
| | - Iuliia Polina
- Department of Medicine, Medical University of South Carolina, Charleston, United States of America
| | - Adrian Zietara
- Department of Physiology, Medical College of Wisconsin, Milwaukee, United States of America
| | - Mark Paterson
- Department of Physiology, Medical College of Wisconsin, Milwaukee, United States of America
| | - Alison J Kriegel
- Department of Physiology, Medical College of Wisconsin, Milwaukee, United States of America
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9
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Haruhara K, Suzuki T, Wakui H, Azushima K, Kurotaki D, Kawase W, Uneda K, Kobayashi R, Ohki K, Kinguchi S, Yamaji T, Kato I, Ohashi K, Yamashita A, Tamura T, Tsuboi N, Yokoo T, Tamura K. Deficiency of the kidney tubular angiotensin II type1 receptor-associated protein ATRAP exacerbates streptozotocin-induced diabetic glomerular injury via reducing protective macrophage polarization. Kidney Int 2022; 101:912-928. [PMID: 35240129 DOI: 10.1016/j.kint.2022.01.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 12/22/2021] [Accepted: 01/11/2022] [Indexed: 12/13/2022]
Abstract
Although activation of the renin-angiotensin system and of its glomerular components is implicated in the pathogenesis of diabetic nephropathy, the functional roles of the tubular renin-angiotensin system with AT1 receptor signaling in diabetic nephropathy are unclear. Tissue hyperactivity of the renin-angiotensin system is inhibited by the angiotensin II type 1 receptor-associated protein ATRAP, which negatively regulates receptor signaling. The highest expression of endogenous ATRAP occurs in the kidney, where it is mainly expressed by tubules but rarely in glomeruli. Here, we found that hyperactivation of angiotensin II type 1 receptor signaling in kidney tubules exacerbated diabetic glomerular injury in a mouse model of streptozotocin-induced diabetic nephropathy. These phenomena were accompanied by decreased expression of CD206, a marker of alternatively activated and tissue-reparative M2 macrophages, in the kidney tubulointerstitium. Additionally, adoptive transfer of M2- polarized macrophages into diabetic ATRAP-knockout mice ameliorated the glomerular injury. As a possible mechanism, the glomerular mRNA levels of tumor necrosis factor-α and oxidative stress components were increased in diabetic knockout mice compared to non-diabetic knockout mice, but these increases were ameliorated by adoptive transfer. Furthermore, proximal tubule-specific ATRAP downregulation reduced tubulointerstitial expression of CD206, the marker of M2 macrophages in diabetic mice. Thus, our findings indicate that tubular ATRAP-mediated functional modulation of angiotensin II type 1 receptor signaling modulates the accumulation of tubulointerstitial M2 macrophages, thus affecting glomerular manifestations of diabetic nephropathy via tubule-glomerular crosstalk.
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Affiliation(s)
- Kotaro Haruhara
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan; Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Toru Suzuki
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Hiromichi Wakui
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
| | - Kengo Azushima
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
| | - Daisuke Kurotaki
- Department of Immunology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Wataru Kawase
- Department of Immunology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kazushi Uneda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Ryu Kobayashi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kohji Ohki
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Sho Kinguchi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Takahiro Yamaji
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan; Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore
| | - Ikuma Kato
- Department of Molecular Pathology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kenichi Ohashi
- Department of Pathology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Akio Yamashita
- Department of Molecular Biology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomohiko Tamura
- Department of Immunology, Yokohama City University Graduate School of Medicine, Yokohama, Japan; Advanced Medical Research Center, Yokohama City University, Yokohama, Japan
| | - Nobuo Tsuboi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kouichi Tamura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
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10
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ATRAP, a receptor-interacting modulator of kidney physiology, as a novel player in blood pressure and beyond. Hypertens Res 2022; 45:32-39. [PMID: 34642449 DOI: 10.1038/s41440-021-00776-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/06/2021] [Accepted: 09/07/2021] [Indexed: 12/16/2022]
Abstract
Pathological activation of kidney angiotensin II (Ang II) type 1 receptor (AT1R) signaling stimulates tubular sodium transporters, including epithelial sodium channels, to increase sodium reabsorption and blood pressure. During a search for a means to functionally and selectively modulate AT1R signaling, a molecule directly interacting with the carboxyl-terminal cytoplasmic domain of AT1R was identified and named AT1R-associated protein (ATRAP/Agtrap). We showed that ATRAP promotes constitutive AT1R internalization to inhibit pathological AT1R activation in response to certain stimuli. In the kidney, ATRAP is abundantly distributed in epithelial cells along the proximal and distal tubules. Results from genetically engineered mice with modified ATRAP expression show that ATRAP plays a key role in the regulation of renal sodium handling and the modulation of blood pressure in response to pathological stimuli and further suggest that the function of kidney tubule ATRAP may be different between distal tubules and proximal tubules, implying that ATRAP is a target of interest in hypertension.
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11
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Urate S, Wakui H, Azushima K, Yamaji T, Suzuki T, Abe E, Tanaka S, Taguchi S, Tsukamoto S, Kinguchi S, Uneda K, Kanaoka T, Atobe Y, Funakoshi K, Yamashita A, Tamura K. Aristolochic Acid Induces Renal Fibrosis and Senescence in Mice. Int J Mol Sci 2021; 22:ijms222212432. [PMID: 34830314 PMCID: PMC8618437 DOI: 10.3390/ijms222212432] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 11/12/2021] [Accepted: 11/12/2021] [Indexed: 01/02/2023] Open
Abstract
The kidney is one of the most susceptible organs to age-related impairments. Generally, renal aging is accompanied by renal fibrosis, which is the final common pathway of chronic kidney diseases. Aristolochic acid (AA), a nephrotoxic agent, causes AA nephropathy (AAN), which is characterized by progressive renal fibrosis and functional decline. Although renal fibrosis is associated with renal aging, whether AA induces renal aging remains unclear. The aim of the present study is to investigate the potential use of AAN as a model of renal aging. Here, we examined senescence-related factors in AAN models by chronically administering AA to C57BL/6 mice. Compared with controls, the AA group demonstrated aging kidney phenotypes, such as renal atrophy, renal functional decline, and tubulointerstitial fibrosis. Additionally, AA promoted cellular senescence specifically in the kidneys, and increased renal p16 mRNA expression and senescence-associated β-galactosidase activity. Furthermore, AA-treated mice exhibited proximal tubular mitochondrial abnormalities, as well as reactive oxygen species accumulation. Klotho, an antiaging gene, was also significantly decreased in the kidneys of AA-treated mice. Collectively, the results of the present study indicate that AA alters senescence-related factors, and that renal fibrosis is closely related to renal aging.
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MESH Headings
- Aging/drug effects
- Aging/genetics
- Animals
- Aristolochic Acids/pharmacology
- Collagen/agonists
- Collagen/genetics
- Collagen/metabolism
- Cyclin-Dependent Kinase Inhibitor p16/genetics
- Cyclin-Dependent Kinase Inhibitor p16/metabolism
- Disease Models, Animal
- Fibrosis
- Gene Expression Regulation
- Humans
- Kidney/drug effects
- Kidney/metabolism
- Kidney/pathology
- Klotho Proteins/genetics
- Klotho Proteins/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mitochondria/drug effects
- Mitochondria/metabolism
- Mitochondria/pathology
- Nephritis, Interstitial/chemically induced
- Nephritis, Interstitial/genetics
- Nephritis, Interstitial/metabolism
- Nephritis, Interstitial/pathology
- Reactive Oxygen Species/agonists
- Reactive Oxygen Species/metabolism
- Renal Insufficiency, Chronic/chemically induced
- Renal Insufficiency, Chronic/genetics
- Renal Insufficiency, Chronic/metabolism
- Renal Insufficiency, Chronic/pathology
- Signal Transduction
- Transforming Growth Factor beta/agonists
- Transforming Growth Factor beta/genetics
- Transforming Growth Factor beta/metabolism
- beta-Galactosidase/genetics
- beta-Galactosidase/metabolism
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Affiliation(s)
- Shingo Urate
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (S.U.); (K.A.); (T.S.); (E.A.); (S.T.); (S.T.); (S.T.); (S.K.); (K.U.); (T.K.); (K.T.)
| | - Hiromichi Wakui
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (S.U.); (K.A.); (T.S.); (E.A.); (S.T.); (S.T.); (S.T.); (S.K.); (K.U.); (T.K.); (K.T.)
- Correspondence: ; Tel.: +81-45-787-2635
| | - Kengo Azushima
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (S.U.); (K.A.); (T.S.); (E.A.); (S.T.); (S.T.); (S.T.); (S.K.); (K.U.); (T.K.); (K.T.)
| | - Takahiro Yamaji
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore;
| | - Toru Suzuki
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (S.U.); (K.A.); (T.S.); (E.A.); (S.T.); (S.T.); (S.T.); (S.K.); (K.U.); (T.K.); (K.T.)
| | - Eriko Abe
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (S.U.); (K.A.); (T.S.); (E.A.); (S.T.); (S.T.); (S.T.); (S.K.); (K.U.); (T.K.); (K.T.)
| | - Shohei Tanaka
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (S.U.); (K.A.); (T.S.); (E.A.); (S.T.); (S.T.); (S.T.); (S.K.); (K.U.); (T.K.); (K.T.)
| | - Shinya Taguchi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (S.U.); (K.A.); (T.S.); (E.A.); (S.T.); (S.T.); (S.T.); (S.K.); (K.U.); (T.K.); (K.T.)
| | - Shunichiro Tsukamoto
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (S.U.); (K.A.); (T.S.); (E.A.); (S.T.); (S.T.); (S.T.); (S.K.); (K.U.); (T.K.); (K.T.)
| | - Sho Kinguchi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (S.U.); (K.A.); (T.S.); (E.A.); (S.T.); (S.T.); (S.T.); (S.K.); (K.U.); (T.K.); (K.T.)
| | - Kazushi Uneda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (S.U.); (K.A.); (T.S.); (E.A.); (S.T.); (S.T.); (S.T.); (S.K.); (K.U.); (T.K.); (K.T.)
| | - Tomohiko Kanaoka
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (S.U.); (K.A.); (T.S.); (E.A.); (S.T.); (S.T.); (S.T.); (S.K.); (K.U.); (T.K.); (K.T.)
| | - Yoshitoshi Atobe
- Department of Neuroanatomy, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (Y.A.); (K.F.)
| | - Kengo Funakoshi
- Department of Neuroanatomy, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (Y.A.); (K.F.)
| | - Akio Yamashita
- Department of Investigative Medicine, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Okinawa 903-0215, Japan;
| | - Kouichi Tamura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan; (S.U.); (K.A.); (T.S.); (E.A.); (S.T.); (S.T.); (S.T.); (S.K.); (K.U.); (T.K.); (K.T.)
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12
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Polidoro JZ, Rebouças NA, Girardi ACC. The Angiotensin II Type 1 Receptor-Associated Protein Attenuates Angiotensin II-Mediated Inhibition of the Renal Outer Medullary Potassium Channel in Collecting Duct Cells. Front Physiol 2021; 12:642409. [PMID: 34054566 PMCID: PMC8160308 DOI: 10.3389/fphys.2021.642409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 04/16/2021] [Indexed: 11/13/2022] Open
Abstract
Adjustments in renal K+ excretion constitute a central mechanism for K+ homeostasis. The renal outer medullary potassium (ROMK) channel accounts for the major K+ secretory route in collecting ducts during basal conditions. Activation of the angiotensin II (Ang II) type 1 receptor (AT1R) by Ang II is known to inhibit ROMK activity under the setting of K+ dietary restriction, underscoring the role of the AT1R in K+ conservation. The present study aimed to investigate whether an AT1R binding partner, the AT1R-associated protein (ATRAP), impacts Ang II-mediated ROMK regulation in collecting duct cells and, if so, to gain insight into the potential underlying mechanisms. To this end, we overexpressed either ATRAP or β-galactosidase (LacZ; used as a control), in M-1 cells, a model line of cortical collecting duct cells. We then assessed ROMK channel activity by employing a novel fluorescence-based microplate assay. Experiments were performed in the presence of 10−10 M Ang II or vehicle for 40 min. We observed that Ang II-induced a significant inhibition of ROMK in LacZ, but not in ATRAP-overexpressed M-1 cells. Inhibition of ROMK-mediated K+ secretion by Ang II was accompanied by lower ROMK cell surface expression. Conversely, Ang II did not affect the ROMK-cell surface abundance in M-1 cells transfected with ATRAP. Additionally, diminished response to Ang II in M-1 cells overexpressing ATRAP was accompanied by decreased c-Src phosphorylation at the tyrosine 416. Unexpectedly, reduced phospho-c-Src levels were also found in M-1 cells, overexpressing ATRAP treated with vehicle, suggesting that ATRAP can also downregulate this kinase independently of Ang II-AT1R activation. Collectively, our data support that ATRAP attenuates inhibition of ROMK by Ang II in collecting duct cells, presumably by reducing c-Src activation and blocking ROMK internalization. The potential role of ATRAP in K+ homeostasis and/or disorders awaits further investigation.
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Affiliation(s)
| | - Nancy Amaral Rebouças
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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13
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Ishii T, Kumagae T, Wakui H, Urate S, Tanaka S, Abe E, Suzuki T, Yamaji T, Kinguchi S, Kobayashi R, Haruhara K, Nakamura T, Kobayashi S, Tamura K. Tissue xanthine oxidoreductase activity in a mouse model of aristolochic acid nephropathy. FEBS Open Bio 2021; 11:507-518. [PMID: 33448693 PMCID: PMC7876505 DOI: 10.1002/2211-5463.13083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 12/02/2020] [Accepted: 12/24/2020] [Indexed: 01/09/2023] Open
Abstract
Xanthine oxidoreductase (XOR) is a critical enzyme in purine metabolism and uric acid production, and its levels are reported to increase during stress, thereby promoting organ damage. Herein, we investigated the activity of XOR in a mouse model of aristolochic acid I (AA)-induced nephropathy, a type of nephrotoxic chronic kidney disease (CKD). A persistent decrease in renal function was observed in mice up to 4 weeks after 4 weeks of AA (2.5 mg kg-1 ) administration. Renal histology revealed an increase in tubular interstitial fibrosis over time. Although AA administration did not change XOR activity in the plasma, heart, liver, or muscle, XOR activity was persistently increased in renal tissue. Our results suggest that the renal tissue-specific increase in XOR activity is involved in the progression of tubulo-interstitial disorders, specifically fibrosis.
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Affiliation(s)
- Takeo Ishii
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Kanagawa, Japan.,Department of Medicine, Yokohama Daiichi Hospital, Kanagawa, Japan
| | - Tomohiro Kumagae
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Kanagawa, Japan.,Department of General Internal Medicine, Shonan Kamakura General Hospital, Kanagawa, Japan
| | - Hiromichi Wakui
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Kanagawa, Japan
| | - Shingo Urate
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Kanagawa, Japan
| | - Shohei Tanaka
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Kanagawa, Japan
| | - Eriko Abe
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Kanagawa, Japan
| | - Toru Suzuki
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Kanagawa, Japan
| | - Takahiro Yamaji
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Kanagawa, Japan
| | - Sho Kinguchi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Kanagawa, Japan
| | - Ryu Kobayashi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Kanagawa, Japan
| | - Kotaro Haruhara
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Kanagawa, Japan
| | - Takashi Nakamura
- Medical Affairs Department, Sanwa Kagaku Kenkusho., Co., Ltd, Aichi, Japan
| | - Shuzo Kobayashi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Kanagawa, Japan.,Department of General Internal Medicine, Shonan Kamakura General Hospital, Kanagawa, Japan
| | - Kouichi Tamura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Kanagawa, Japan
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14
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Polina I, Domondon M, Fox R, Sudarikova AV, Troncoso M, Vasileva VY, Kashyrina Y, Gooz MB, Schibalski RS, DeLeon-Pennell KY, Fitzgibbon WR, Ilatovskaya DV. Differential effects of low-dose sacubitril and/or valsartan on renal disease in salt-sensitive hypertension. Am J Physiol Renal Physiol 2020; 319:F63-F75. [PMID: 32463726 PMCID: PMC7468826 DOI: 10.1152/ajprenal.00125.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/20/2020] [Accepted: 05/20/2020] [Indexed: 12/15/2022] Open
Abstract
Diuretics and renin-angiotensin system blockers are often insufficient to control the blood pressure (BP) in salt-sensitive (SS) subjects. Abundant data support the proposal that the level of atrial natriuretic peptide may correlate with the pathogenesis of SS hypertension. We hypothesized here that increasing atrial natriuretic peptide levels with sacubitril, combined with renin-angiotensin system blockage by valsartan, can be beneficial for alleviation of renal damage in a model of SS hypertension, the Dahl SS rat. To induce a BP increase, rats were challenged with a high-salt 4% NaCl diet for 21 days, and chronic administration of vehicle or low-dose sacubitril and/or valsartan (75 μg/day each) was performed. Urine flow, Na+ excretion, and water consumption were increased on the high-salt diet compared with the starting point (0.4% NaCl) in all groups but remained similar among the groups at the end of the protocol. Upon salt challenge, we observed a mild decrease in systolic BP and urinary neutrophil gelatinase-associated lipocalin levels (indicative of alleviated tubular damage) in the valsartan-treated groups. Sacubitril, as well as sacubitril/valsartan, attenuated the glomerular filtration rate decline induced by salt. Alleviation of protein cast formation and lower renal medullary fibrosis were observed in the sacubitril/valsartan- and valsartan-treated groups, but not when sacubitril alone was administered. Interestingly, proteinuria was mildly mitigated only in rats that received sacubitril/valsartan. Further studies of the effects of sacubitril/valsartan in the setting of SS hypertension, perhaps involving a higher dose of the drug, are warranted to determine if it can interfere with the progression of the disease.
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Affiliation(s)
- Iuliia Polina
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Mark Domondon
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Rebecca Fox
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Anastasia V Sudarikova
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Miguel Troncoso
- Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Valeriia Y Vasileva
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Yuliia Kashyrina
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Monika Beck Gooz
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina
| | - Ryan S Schibalski
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Kristine Y DeLeon-Pennell
- Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina
| | - Wayne R Fitzgibbon
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Daria V Ilatovskaya
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
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15
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Wakui H. The pathophysiological role of angiotensin receptor-binding protein in hypertension and kidney diseases: Oshima Award Address 2019. Clin Exp Nephrol 2020; 24:289-294. [PMID: 32112267 PMCID: PMC7131980 DOI: 10.1007/s10157-020-01861-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 02/07/2020] [Indexed: 01/10/2023]
Abstract
Excessive activation of the tissue renin–angiotensin system through angiotensin II (Ang II) type 1 receptor (AT1R) plays a pivotal role in the pathogenesis of hypertension and related organ injury. AT1R-associated protein (ATRAP/Agtrap) was identified as a molecule specifically interacting with the carboxyl- terminal domain of AT1R. The results of in vitro studies showed that ATRAP suppresses Ang II-mediated pathological responses in cardiovascular cells by promoting AT1R internalization. With respect to the tissue distribution and regulation of ATRAP expression in vivo, ATRAP is broadly expressed in many tissues as is AT1R including kidney. The results of in vivo study employing genetic engineered mice with modified ATRAP expression showed that ATRAP inhibits cardiovascular injuries provoked by Ang II-induced hypertension, along with preserving physiological AT1R signaling. In addition, we have shown that ATRAP functions as an endogenous modulator so as to prevent hypertension in response to pathological stimuli, by regulating renal sodium handling. Furthermore, ATRAP may have an AT1R-independent function of renal proximal tubule to protect aging and fibrosis. These results suggest the clinical potential benefit of an ATRAP activation strategy in the treatment of hypertension and cardiorenal and vascular diseases.
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Affiliation(s)
- Hiromichi Wakui
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.
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16
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Abstract
PURPOSE OF REVIEW The renin-angiotensin-aldosterone system (RAAS) plays important roles in regulating blood pressure and body fluid, which contributes to the pathophysiology of hypertension and cardiovascular/renal diseases. However, accumulating evidence has further revealed the complexity of this signal transduction system, including direct interactions with other receptors and proteins. This review focuses on recent research advances in RAAS with an emphasis on its receptors. RECENT FINDINGS Both systemically and locally produced angiotensin II (Ang II) bind to Ang II type 1 receptor (AT1R) and elicit strong biological functions. Recent studies have shown that Ang II-induced activation of Ang II type 2 receptor (AT2R) elicits the opposite functions to those of AT1R. However, accumulating evidence has now expanded the components of RAAS, including (pro)renin receptor, angiotensin-converting enzyme 2, angiotensin 1-7, and Mas receptor. In addition, the signal transductions of AT1R and AT2R are regulated by not only Ang II but also its receptor-associated proteins such as AT1R-associated protein and AT2R-interacting protein. Recent studies have indicated that inappropriate activation of local mineralocorticoid receptor contributes to cardiovascular and renal tissue injuries through aldosterone-dependent and -independent mechanisms. Since the mechanisms of RAAS signal transduction still remain to be elucidated, further investigations are necessary to explore novel molecular mechanisms of the RAAS, which will provide alternative therapeutic agents other than existing RAAS blockers.
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17
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Wakui H, Yamaji T, Azushima K, Uneda K, Haruhara K, Nakamura A, Ohki K, Kinguchi S, Kobayashi R, Urate S, Suzuki T, Kamimura D, Minegishi S, Ishigami T, Kanaoka T, Matsuo K, Miyazaki T, Fujikawa T, Yamashita A, Tamura K. Effects of Rikkunshito treatment on renal fibrosis/inflammation and body weight reduction in a unilateral ureteral obstruction model in mice. Sci Rep 2020; 10:1782. [PMID: 32024850 PMCID: PMC7002622 DOI: 10.1038/s41598-020-58214-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 01/13/2020] [Indexed: 11/09/2022] Open
Abstract
Chronic kidney disease (CKD) progresses to end-stage renal failure via renal tubulointerstitial fibrosis. Malnutrition, inflammation, and arteriosclerosis interact to exacerbate the poor prognosis of CKD, and their effective management is thus essential. The traditional Japanese medicine Rikkunshito (RKT) exerts appetite-stimulating effects via ghrelin, which attenuates inflammation and fibrosis. We evaluated the therapeutic effect of RKT in unilateral ureter obstruction (UUO)-induced renal fibrosis/inflammation and body weight loss in mice. UUO and sham-operated mice were fed a standard diet or diet containing 3.0% RKT. Renal fibrosis was investigated by histopathology and macrophage infiltration was determined by immunohistochemistry. Expression levels of genes associated with fibrosis, inflammation, ghrelin, and mitochondrial function were determined by quantitative reverse transcription-polymerase chain reaction and western blot analyses. RKT treatment partially prevented UUO-induced weight loss but failed to attenuate renal fibrosis and inflammation. Renal expression of sirtuin 1, a ghrelin-downstream signalling molecule, and gene expression of peroxisome proliferator-activated receptor-γ coactivator 1α and Bcl-2/adenovirus E1B interacting protein 3 were unaffected by RKT. These results indicate that RKT inhibits weight loss but does not improve renal fibrosis or inflammation in a rapidly progressive renal fibrosis mouse model. RKT may have a protective effect on weight loss associated with CKD.
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Affiliation(s)
- Hiromichi Wakui
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
| | - Takahiro Yamaji
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kengo Azushima
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan. .,Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore.
| | - Kazushi Uneda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kotaro Haruhara
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan.,Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Akiko Nakamura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kohji Ohki
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Sho Kinguchi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Ryu Kobayashi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Shingo Urate
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Toru Suzuki
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Daisuke Kamimura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Shintaro Minegishi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomoaki Ishigami
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomohiko Kanaoka
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kohei Matsuo
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomoyuki Miyazaki
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tetsuya Fujikawa
- Center for Health Service Sciences, Yokohama National University, Yokohama, Japan
| | - Akio Yamashita
- Department of Molecular Biology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kouichi Tamura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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18
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Angiotensin II type 1 receptor-associated protein deficiency attenuates sirtuin1 expression in an immortalised human renal proximal tubule cell line. Sci Rep 2019; 9:16550. [PMID: 31719572 PMCID: PMC6851135 DOI: 10.1038/s41598-019-52566-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 10/17/2019] [Indexed: 11/08/2022] Open
Abstract
The proximal tubule is a particularly important site for ageing-related kidney damage. Sirtuin 1 (SIRT1), an NAD+ (nicotinamide adenine dinucleotide)-dependent deacetylase in the proximal tubule, may be involved in renal injury associated with ageing. However, the mechanisms of SIRT1 regulation remain to be elucidated. We recently reported that angiotensin II type 1 receptor (AT1R)-associated protein (ATRAP)-deficient mice displayed age-associated renal function decline and tubulointerstitial fibrosis. Our data showed that SIRT1 protein expression was reduced in ATRAP-deficient mice, although the relationship between ATRAP deficiency and age-associated renal fibrosis is still not fully understood. It is, therefore, necessary to investigate how ATRAP affects SIRT1 protein expression to resolve ageing-associated kidney dysfunction. Here, since ageing studies are inherently lengthy, we used an ex vivo model of the proximal tubule to determine the role of ATRAP in SIRT1 protein expression. We first generated a clonal immortalised human renal proximal tubule epithelial cell line (ciRPTEC) expressing AT1R and ATRAP. Using this cell line, we demonstrated that ATRAP knockdown reduced SIRT1 protein expression in the ciRPTEC but did not alter SIRT1 mRNA expression. Thus, ATRAP likely mediates SIRT1 protein abundance in ciRPTEC.
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19
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Effects of rikkunshito on renal fibrosis and inflammation in angiotensin II-infused mice. Sci Rep 2019; 9:6201. [PMID: 30996242 PMCID: PMC6470237 DOI: 10.1038/s41598-019-42657-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 04/02/2019] [Indexed: 02/07/2023] Open
Abstract
The underlying pathogenesis of chronic kidney disease involves an activated renin-angiotensin system and systemic inflammation which ultimately develop renal injury. Rikkunshito (RKT) has been reported to exert anti-fibrotic and anti-inflammatory effects through enhancement of ghrelin signaling pathway. In this study, we investigated the effects of RKT on renal fibrosis and inflammation in angiotensin II (Ang II)-induced renal injury model. Ang II-infused mice exhibited hypertension, cardiac hypertrophy, increases in blood urea nitrogen and serum creatinine, moderate albuminuria and renal pathological changes such as mild urinary cast, interstitial macrophage infiltration and modest interstitial fibrosis. RKT had no evident effects on the Ang II-induced renal functional insufficiency and fibrosis, but attenuated renal interstitial macrophage infiltration. In addition, RKT significantly restored the Ang II-induced alteration in the expression of renal fibrosis- and inflammation-related genes such as type 3 collagen, transforming growth factor-β, monocyte chemoattractant protein-1 and interleukin-6. Furthermore, although RKT did not affect the expression of renal ghrelin receptor, an Ang II-induced decrease in renal sirtuin 1 expression, a critical down-stream pathway of the ghrelin receptor, was restored by RKT. These findings suggest that RKT potentially has a renal anti-inflammatory effect in the development of renal injury, and this effect could be mediated by the ghrelin signaling pathway.
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20
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Kinguchi S, Wakui H, Azushima K, Haruhara K, Koguchi T, Ohki K, Uneda K, Matsuda M, Haku S, Yamaji T, Yamada T, Kobayashi R, Minegishi S, Ishigami T, Yamashita A, Fujikawa T, Tamura K. Effects of ATRAP in Renal Proximal Tubules on Angiotensin-Dependent Hypertension. J Am Heart Assoc 2019; 8:e012395. [PMID: 30977419 PMCID: PMC6507205 DOI: 10.1161/jaha.119.012395] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Background We have previously shown that ATRAP (angiotensin II receptor-associated protein; Agtrap) interacts with AT1R (angiotensin II type 1 receptor) and promotes constitutive internalization of AT 1R so as to inhibit hyperactivation of its downstream signaling. In response to angiotensin II , systemic ATRAP deficiency exacerbates angiotensin II -mediated hypertension via hyperactivation of renal tubular AT 1R. Although ATRAP expression is abundant in renal proximal tubules, little is known about the actual function of renal proximal tubule ATRAP in angiotensin-mediated hypertension. Methods and Results In this study, we examined the in vivo functional role of renal proximal tubule ATRAP in angiotensin-dependent hypertension. We succeeded in generating proximal tubule-specific ATRAP knockout ( PT - KO ) mice for the first time using the Cre/loxP system with Pepck-Cre. Detailed analysis of renal ATRAP expression in PT - KO mice estimated by immunohistochemical and laser-capture microdissection analysis revealed that ATRAP mRNA expression decreased by ≈80% in proximal regions of the nephron in PT - KO mice compared with wild-type ( WT ) mice. We compared blood pressure of PT - KO and WT mice using both tail-cuff and radiotelemetric methods. Blood pressure of PT - KO mice was comparable with that of WT mice at baseline. Moreover, no significant differences were noted in pressor response to angiotensin II (600 ng/kg per min or 1000 ng/kg per minute) infusion between PT - KO and WT mice. In addition, angiotensin II -mediated cardiac hypertrophy was identical between PT - KO and WT mice. Conclusions ATRAP deficiency in proximal tubules did not exacerbate angiotensin-dependent hypertension in vivo. The results indicate that renal proximal tubule ATRAP has a minor role in angiotensin-dependent hypertension in vivo.
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Affiliation(s)
- Sho Kinguchi
- 1 Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Hiromichi Wakui
- 1 Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Kengo Azushima
- 1 Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan.,2 Cardiovascular and Metabolic Disorders Program Duke-NUS Medical School Singapore Singapore
| | - Kotaro Haruhara
- 1 Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Tomoyuki Koguchi
- 1 Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Kohji Ohki
- 1 Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Kazushi Uneda
- 1 Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Miyuki Matsuda
- 1 Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Sona Haku
- 1 Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Takahiro Yamaji
- 1 Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Takayuki Yamada
- 1 Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Ryu Kobayashi
- 1 Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Shintaro Minegishi
- 1 Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Tomoaki Ishigami
- 1 Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Akio Yamashita
- 3 Department of Molecular Biology Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Tetsuya Fujikawa
- 4 Center for Health Service Sciences Yokohama National University Yokohama Japan
| | - Kouichi Tamura
- 1 Department of Medical Science and Cardiorenal Medicine Yokohama City University Graduate School of Medicine Yokohama Japan
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21
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Gonzalez-Vicente A, Saez F, Monzon CM, Asirwatham J, Garvin JL. Thick Ascending Limb Sodium Transport in the Pathogenesis of Hypertension. Physiol Rev 2019; 99:235-309. [PMID: 30354966 DOI: 10.1152/physrev.00055.2017] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The thick ascending limb plays a key role in maintaining water and electrolyte balance. The importance of this segment in regulating blood pressure is evidenced by the effect of loop diuretics or local genetic defects on this parameter. Hormones and factors produced by thick ascending limbs have both autocrine and paracrine effects, which can extend prohypertensive signaling to other structures of the nephron. In this review, we discuss the role of the thick ascending limb in the development of hypertension, not as a sole participant, but one that works within the rich biological context of the renal medulla. We first provide an overview of the basic physiology of the segment and the anatomical considerations necessary to understand its relationship with other renal structures. We explore the physiopathological changes in thick ascending limbs occurring in both genetic and induced animal models of hypertension. We then discuss the racial differences and genetic defects that affect blood pressure in humans through changes in thick ascending limb transport rates. Throughout the text, we scrutinize methodologies and discuss the limitations of research techniques that, when overlooked, can lead investigators to make erroneous conclusions. Thus, in addition to advancing an understanding of the basic mechanisms of physiology, the ultimate goal of this work is to understand our research tools, to make better use of them, and to contextualize research data. Future advances in renal hypertension research will require not only collection of new experimental data, but also integration of our current knowledge.
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Affiliation(s)
| | - Fara Saez
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Casandra M Monzon
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jessica Asirwatham
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jeffrey L Garvin
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
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22
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Early Enhanced Leucine-Rich α-2-Glycoprotein-1 Expression in Glomerular Endothelial Cells of Type 2 Diabetic Nephropathy Model Mice. BIOMED RESEARCH INTERNATIONAL 2018; 2018:2817045. [PMID: 30515388 PMCID: PMC6236974 DOI: 10.1155/2018/2817045] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/03/2018] [Indexed: 12/15/2022]
Abstract
Abnormal angiogenesis plays a major role in the development of early stage diabetic nephropathy. Vascular endothelial growth factor (VEGF) is a classical proangiogenic factor that regulates abnormal glomerular angiogenesis linked to glomerular hypertrophy in the early stage of diabetic nephropathy. Leucine-rich α-2-glycoprotein-1 (LRG1) was recently reported as a novel proangiogenic factor that is expressed in endothelial cells and promotes angiogenesis by modulating the transforming growth factor-β signaling pathway. However, the pathophysiology of LRG1 in diabetic nephropathy remains largely unknown. In the present study, we investigated intrarenal expression of the novel proangiogenic factor LRG1 in diabetic db/db mice by immunohistochemistry and a laser capture microdissection method during the development of diabetic nephropathy. We hypothesized that glomerular LRG1 expression is increased earlier than VEGF expression under conditions of pathological angiogenesis in the early stage of diabetic nephropathy. Thus, we compared glomerular expression of VEGF and LRG1 in diabetic db/db mice at 16 and 24 weeks of age. At 16 weeks, diabetic db/db mice exhibited glomerular hypertrophy with abnormal angiogenesis characterized by endothelial cell proliferation, which was concomitant with an increase in LRG1 expression of glomerular endothelial cells. However, glomerular VEGF expression was not increased at this early stage. At 24 weeks, the features of early diabetic nephropathy in db/db mice had developed further, along with further enhanced glomerular LRG1 expression. At this late stage, glomerular VEGF and fibrosis-related-gene expression was also significantly increased compared with nondiabetic db/m mice. These results suggest that LRG1 plays a pivotal role in the initial development of diabetic nephropathy by promoting abnormal angiogenesis, thereby suggesting that LRG1 is a potential preemptive therapeutic target of diabetic nephropathy.
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23
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Blood pressure regulation by the angiotensin type 1 receptor in the proximal tubule. Curr Opin Nephrol Hypertens 2018; 27:1-7. [PMID: 29045337 DOI: 10.1097/mnh.0000000000000373] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
PURPOSE OF REVIEW The renin-angiotensin system (RAS) plays a critical role in the pathogenesis of hypertension. Homeostatic actions of the RAS, such as increasing blood pressure (BP) and vasoconstriction, are mediated via type 1 (AT1) receptors for angiotensin II. All components of the RAS are present in the renal proximal tubule, which reabsorbs the bulk of the glomerular filtrate, making this segment of the nephron a location of great interest for solute handling under RAS influence. This review highlights recent studies that illustrate the key role of renal proximal tubule AT1 receptors in BP regulation. RECENT FINDINGS A variety of investigative approaches have demonstrated that angiotensin II signaling via AT1a receptors, specifically in the renal proximal tubule, is a major regulator of BP and sodium homeostasis. Reduction of proximal tubule AT1a receptors led to lower BPs, whereas overexpression generally caused increased BPs. SUMMARY AT1a receptors in the proximal tubule are critical to the regulation of BP by the kidney and the RAS. The pattern of BP modulation is associated with alterations in sodium transporters. As a key site for sodium homeostasis, the renal proximal tubule could hence be a potential target in the treatment of hypertension.
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24
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Uneda K, Wakui H, Maeda A, Azushima K, Kobayashi R, Haku S, Ohki K, Haruhara K, Kinguchi S, Matsuda M, Ohsawa M, Minegishi S, Ishigami T, Toya Y, Atobe Y, Yamashita A, Umemura S, Tamura K. Angiotensin II Type 1 Receptor-Associated Protein Regulates Kidney Aging and Lifespan Independent of Angiotensin. J Am Heart Assoc 2017; 6:JAHA.117.006120. [PMID: 28751545 PMCID: PMC5586453 DOI: 10.1161/jaha.117.006120] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Background The kidney is easily affected by aging‐associated changes, including glomerulosclerosis, tubular atrophy, and interstitial fibrosis. Particularly, renal tubulointerstitial fibrosis is a final common pathway in most forms of progressive renal disease. Angiotensin II type 1 receptor (AT1R)‐associated protein (ATRAP), which was originally identified as a molecule that binds to AT1R, is highly expressed in the kidney. Previously, we have shown that ATRAP suppresses hyperactivation of AT1R signaling, but does not affect physiological AT1R signaling. Methods and Results We hypothesized that ATRAP has a novel functional role in the physiological age‐degenerative process, independent of modulation of AT1R signaling. ATRAP‐knockout mice were used to study the functional involvement of ATRAP in the aging. ATRAP‐knockout mice exhibit a normal age‐associated appearance without any evident alterations in physiological parameters, including blood pressure and cardiovascular and metabolic phenotypes. However, in ATRAP‐knockout mice compared with wild‐type mice, the following takes place: (1) age‐associated renal function decline and tubulointerstitial fibrosis are more enhanced; (2) renal tubular mitochondrial abnormalities and subsequent increases in the production of reactive oxygen species are more advanced; and (3) life span is 18.4% shorter (median life span, 100.4 versus 123.1 weeks). As a key mechanism, age‐related pathological changes in the kidney of ATRAP‐knockout mice correlated with decreased expression of the prosurvival gene, Sirtuin1. On the other hand, chronic angiotensin II infusion did not affect renal sirtuin1 expression in wild‐type mice. Conclusions These results indicate that ATRAP plays an important role in inhibiting kidney aging, possibly through sirtuin1‐mediated mechanism independent of blocking AT1R signaling, and further protecting normal life span.
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Affiliation(s)
- Kazushi Uneda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Hiromichi Wakui
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Akinobu Maeda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kengo Azushima
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan .,Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore
| | - Ryu Kobayashi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Sona Haku
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kohji Ohki
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kotaro Haruhara
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Sho Kinguchi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Miyuki Matsuda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Masato Ohsawa
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Shintaro Minegishi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomoaki Ishigami
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Yoshiyuki Toya
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Yoshitoshi Atobe
- Department of Neuroanatomy, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Akio Yamashita
- Department of Molecular Biology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Satoshi Umemura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan.,Yokohama Rosai Hospital, Yokohama, Japan
| | - Kouichi Tamura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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25
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Wakui H, Sumida K, Fujita M, Ohtomo Y, Ohsawa M, Kobayashi R, Uneda K, Azushima K, Haruhara K, Yatsu K, Hirawa N, Minegishi S, Ishigami T, Umemura S, Tamura K. Enhancement of intrarenal plasma membrane calcium pump isoform 1 expression in chronic angiotensin II-infused mice. Physiol Rep 2017; 5:5/11/e13316. [PMID: 28611155 PMCID: PMC5471448 DOI: 10.14814/phy2.13316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 05/13/2017] [Accepted: 05/15/2017] [Indexed: 12/24/2022] Open
Abstract
Plasma membrane calcium pump isoform 1 (PMCA1) is encoded by ATPase plasma membrane Ca2+transporting 1 (ATP2B1), the most likely candidate gene responsible for hypertension. Although PMCA1 is highly expressed in the kidney, little is known about regulation of its renal expression in various pathological conditions in vivo. Our study was designed to elucidate regulation of renal PMCA1 expression in mice. We employed three mouse models for kidney disease. These were the unilateral ureteral obstruction (UUO), the remnant kidney using 5/6 nephrectomy, and chronic angiotensin II administration models. Mice were assessed for systolic blood pressure and renal injury in accordance with the damage induced in the specific model. Kidney PMCA1 mRNA levels were measured in all mice. The UUO model showed renal fibrosis but no changes in blood pressure or renal PMCA1 mRNA expression. Similarly, the 5/6 nephrectomy model exhibited declined renal function without changes in blood pressure or renal PMCA1 mRNA expression. In contrast, chronic angiotensin II administration increased albuminuria and blood pressure as well as significantly increasing renal PMCA1 mRNA and protein expression. These results suggest that renal PMCA1 has a role as one of the molecules involved in angiotensin II-induced hypertension and kidney injury.
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Affiliation(s)
- Hiromichi Wakui
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Koichiro Sumida
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Megumi Fujita
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Yuta Ohtomo
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Masato Ohsawa
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Ryu Kobayashi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Kazushi Uneda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Kengo Azushima
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Kotaro Haruhara
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Keisuke Yatsu
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Nobuhito Hirawa
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Shintaro Minegishi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Tomoaki Ishigami
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Satoshi Umemura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
| | - Kouichi Tamura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan
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26
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Azushima K, Ohki K, Wakui H, Uneda K, Haku S, Kobayashi R, Haruhara K, Kinguchi S, Matsuda M, Maeda A, Toya Y, Yamashita A, Umemura S, Tamura K. Adipocyte-Specific Enhancement of Angiotensin II Type 1 Receptor-Associated Protein Ameliorates Diet-Induced Visceral Obesity and Insulin Resistance. J Am Heart Assoc 2017; 6:JAHA.116.004488. [PMID: 28264860 PMCID: PMC5524000 DOI: 10.1161/jaha.116.004488] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background The renin–angiotensin system has a pivotal role in the pathophysiology of visceral obesity. Angiotensin II type 1 receptor (AT1R) is a major player in the signal transduction of the renin–angiotensin system, and the overactivation of this signaling contributes to the progression of visceral obesity. We have shown that the AT1R‐associated protein (ATRAP) promotes AT1R internalization from the cell surface into cytoplasm along with the suppression of overactivation of tissue AT1R signaling. In this study, we examined whether the enhancement of adipose ATRAP expression could efficiently prevent diet‐induced visceral obesity and insulin resistance. Methods and Results We generated adipocyte‐specific ATRAP transgenic mice using a 5.4‐kb adiponectin promoter, and transgenic mice and littermate control mice were fed either a low‐ or high‐fat diet for 10 weeks. Although the physiological phenotypes of the transgenic and control mice fed a low‐fat diet were comparable, the transgenic mice exhibited significant protection against high‐fat diet–induced adiposity, adipocyte hypertrophy, and insulin resistance concomitant with an attenuation of adipose inflammation, macrophage infiltration, and adipokine dysregulation. In addition, when mice were fed a high‐fat diet, the adipose expression of glucose transporter type 4 was significantly elevated and the level of adipose phospho‐p38 mitogen‐activated protein kinase was significantly attenuated in the transgenic mice compared with control mice. Conclusions Results presented in this study suggested that the enhancement in adipose ATRAP plays a protective role against the development of diet‐induced visceral obesity and insulin resistance through improvement of adipose inflammation and function via the suppression of overactivation of adipose AT1R signaling. Consequently, adipose tissue ATRAP is suggested to be an effective therapeutic target for the treatment of visceral obesity.
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Affiliation(s)
- Kengo Azushima
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan .,Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore
| | - Kohji Ohki
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Hiromichi Wakui
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kazushi Uneda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Sona Haku
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Ryu Kobayashi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kotaro Haruhara
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Sho Kinguchi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Miyuki Matsuda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Akinobu Maeda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Yoshiyuki Toya
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Akio Yamashita
- Department of Molecular Biology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Satoshi Umemura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kouichi Tamura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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An angiotensin II type 1 receptor binding molecule has a critical role in hypertension in a chronic kidney disease model. Kidney Int 2017; 91:1115-1125. [PMID: 28081856 DOI: 10.1016/j.kint.2016.10.035] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 09/28/2016] [Accepted: 10/27/2016] [Indexed: 01/13/2023]
Abstract
Angiotensin II type 1 receptor-associated protein (ATRAP) promotes AT1R internalization along with suppression of hyperactivation of tissue AT1R signaling. Here, we provide evidence that renal ATRAP plays a critical role in suppressing hypertension in a mouse remnant kidney model of chronic kidney disease. The effect of 5/6 nephrectomy on endogenous ATRAP expression was examined in the kidney of C57BL/6 and 129/Sv mice. While 129/Sv mice with a remnant kidney showed decreased renal ATRAP expression and developed hypertension, C57BL/6 mice exhibited increased renal ATRAP expression and resistance to progressive hypertension. Consequently, we hypothesized that downregulation of renal ATRAP expression is involved in pathogenesis of hypertension in the remnant kidney model of chronic kidney disease. Interestingly, 5/6 nephrectomy in ATRAP-knockout mice on the hypertension-resistant C57BL/6 background caused hypertension with increased plasma volume. Moreover, in knockout compared to wild-type C57BL/6 mice after 5/6 nephrectomy, renal expression of the epithelial sodium channel α-subunit and tumor necrosis factor-α was significantly enhanced, concomitant with increased plasma membrane angiotensin II type 1 receptor in the kidneys. Thus, renal ATRAP downregulation is involved in the onset and progression of blood pressure elevation caused by renal mass reduction, and implicates ATRAP as a therapeutic target for hypertension in chronic kidney disease.
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Haruhara K, Tsuboi N, Koike K, Kanzaki G, Okabayashi Y, Miyazaki Y, Kawamura T, Ogura M, Yokoo T. Ambulatory blood pressure and tubulointerstitial injury in patients with IgA nephropathy. Clin Kidney J 2015; 8:716-21. [PMID: 26613030 PMCID: PMC4655792 DOI: 10.1093/ckj/sfv083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 08/03/2015] [Indexed: 01/11/2023] Open
Abstract
Background Few studies have been conducted to assess the ambulatory blood pressure (ABP) in IgA nephropathy (IgAN) patients. This study aimed to determine the relationships between ABP and renal histopathological findings assessed using the Oxford classification (OC) and the Japanese classification (JC), which have recently established histopathological criteria for IgAN. Methods This cross-sectional study included biopsy-diagnosed IgAN patients, in whom both a renal biopsy and ABP measurement were performed. The histopathological findings were assessed using the OC and the JC and were analyzed in relation to the ABP. Results A total of 111 IgAN patients were included. The score of interstitial fibrosis and tubular atrophy (T score) using the OC was a significantly associated factor with both the daytime and nighttime ABP values. In contrast, the other histopathological scores, including mesangial hypercellularity, endocapillary hypercellularity and segmental glomerulosclerosis, did not show significant associations with the ABP. The histological grade (H-grade) using the JC, which was based on the sum of injured glomeruli, was associated with the daytime ABP, but not with the nighttime ABP. The associations between the T score using the OC (%) and the daytime and nighttime ABP values were independent of age, gender, renal function, proteinuria and the use of antihypertensive medications, whereas the H-grade using the JC (%) did not show significant associations after adjusting for these clinical parameters. Conclusions These results suggest that the T score using the OC is the most relevant renal histopathological parameter associated with abnormalities of circadian blood pressure in IgAN patients.
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Affiliation(s)
- Kotaro Haruhara
- Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan
| | - Nobuo Tsuboi
- Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan
| | - Kentaro Koike
- Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan
| | - Go Kanzaki
- Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan
| | - Yusuke Okabayashi
- Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan
| | - Yoichi Miyazaki
- Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan
| | - Tetsuya Kawamura
- Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan
| | - Makoto Ogura
- Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine , Jikei University School of Medicine , Minato-Ku , Tokyo , Japan
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YUAN LIFEN, SHENG JING, LU PING, WANG YUQIANG, JIN TUO, DU QIN. Nanoparticle-mediated RNA interference of angiotensinogen decreases blood pressure and improves myocardial remodeling in spontaneously hypertensive rats. Mol Med Rep 2015; 12:4657-4663. [DOI: 10.3892/mmr.2015.3909] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 03/23/2015] [Indexed: 11/06/2022] Open
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Huang H, Zhou J, Cui Z, Wang B, Hu Y. Angiotensin II type 1 receptor-associated protein plays a role in regulating the local renin-angiotensin system in HSC-T6 cells. Mol Med Rep 2015; 12:3763-3768. [PMID: 26018598 DOI: 10.3892/mmr.2015.3849] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 11/10/2014] [Indexed: 11/06/2022] Open
Abstract
The aim of the current study was to examine the expression of the angiotensin II type 1 receptor‑associated protein (ATRAP) in the rat hepatic stellate cell line HSC‑T6 and to determine its interactions with the local renin‑angiotensin system (RAS). To achieve this goal, the effect of stimulating HSC‑T6 cells with angiotensin II (AngII) and angiotensin‑(1‑7) [Ang‑(1‑7)], on the expression of ATRAP, the angiotensin II type I receptor (AT1R), the Mas receptor and the angiotensin converting enzyme 2 (ACE2) 2, 6, 12, 18, 24 and 36 h after stimulation was investigated. Changes in expression were quantified at the gene and protein level using RT‑qPCR and western blotting, respectively. A single dose of AngII (1 µmol/l) significantly increased the gene expression of ATRAP at 12 h, whereas ACE2 gene expression levels were significantly increased at 6 h and then returned to baseline at 12 h, prior to becoming significantly lower. A single dose of Ang‑(1‑7) at the same concentration as AngII induced ATRAP gene expression, which became statistically significant at the 6 h time‑point, reached a peak at 12 h and remained elevated throughout the experimental time‑course. In addition, ACE2 mRNA expression was significantly suppressed by Ang‑(1‑7) at 6 h, reaching its lowest expression level at 24 h. The expression of AT1R and the Mas receptor were unaffected by stimulation with AngII and Ang‑(1‑7). The western blotting results were generally consistent with the mRNA expression data. In conclusion, it was identified that ATRAP is endogenously expressed in HSC‑T6 cells and therefore, may be critical in regulating the local RAS in these cells.
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Affiliation(s)
- Haiyang Huang
- Department of Hepatobiliary Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Jie Zhou
- Department of Hepatobiliary Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Zhonglin Cui
- Department of Hepatobiliary Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Biao Wang
- Department of Hepatobiliary Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Yunwei Hu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
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Castrop H. A role for AT1 receptor-associated proteins in blood pressure regulation. Curr Opin Pharmacol 2015; 21:43-7. [DOI: 10.1016/j.coph.2014.12.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 12/18/2014] [Accepted: 12/19/2014] [Indexed: 01/11/2023]
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AT1 Angiotensin receptors—vascular and renal epithelial pathways for blood pressure regulation. Curr Opin Pharmacol 2015; 21:122-6. [DOI: 10.1016/j.coph.2015.01.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 01/23/2015] [Indexed: 01/24/2023]
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Wakui H, Uneda K, Tamura K, Ohsawa M, Azushima K, Kobayashi R, Ohki K, Dejima T, Kanaoka T, Tsurumi-Ikeya Y, Matsuda M, Haruhara K, Nishiyama A, Yabana M, Fujikawa T, Yamashita A, Umemura S. Renal tubule angiotensin II type 1 receptor-associated protein promotes natriuresis and inhibits salt-sensitive blood pressure elevation. J Am Heart Assoc 2015; 4:e001594. [PMID: 25792129 PMCID: PMC4392439 DOI: 10.1161/jaha.114.001594] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Angiotensin II type 1 receptor (AT1R)-associated protein (ATRAP; Agtrap gene) promotes AT1R internalization along with suppression of pathological AT1R activation. In this study, we examined whether enhancement of ATRAP in the renal distal tubules affects sodium handling and blood pressure regulation in response to high salt (HS) loading, using ATRAP transgenic mice on a salt-sensitive C57BL/6J background. METHODS AND RESULTS Renal ATRAP transgenic (rATRAP-Tg) mice, which exhibit renal tubule-dominant ATRAP enhancement, and their wild-type littermate C57BL/6J mice on a normal salt diet (0.3% NaCl) at baseline were subjected to dietary HS loading (4% NaCl) for 7 days. In rATRAP-Tg mice, the dietary HS loading-mediated blood pressure elevation was suppressed compared with wild-type mice, despite similar baseline blood pressure. Although renal angiotensin II level was comparable in rATRAP-Tg and wild-type mice with and without HS loading, urinary sodium excretion in response to HS loading was significantly enhanced in the rATRAP-Tg mice. In addition, functional transport activity of the amiloride-sensitive epithelial Na(+) channel was significantly decreased under saline volume-expanded conditions in rATRAP-Tg mice compared with wild-type mice, without any evident change in epithelial Na(+) channel protein expression. Plasma membrane AT1R expression in the kidney of rATRAP-Tg mice was decreased compared with wild-type mice. CONCLUSIONS These results demonstrated that distal tubule-dominant enhancement of ATRAP inhibits pathological renal sodium reabsorption and blood pressure elevation in response to HS loading. The findings suggest that ATRAP-mediated modulation of sodium handling in renal distal tubules could be a target of interest in salt-sensitive blood pressure regulation.
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Affiliation(s)
- Hiromichi Wakui
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan (H.W., K.U., K.T., M.O., K.A., R.K., K.O., T.D., T.K., Y.T.I., M.M., K.H., M.Y., T.F., S.U.)
| | - Kazushi Uneda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan (H.W., K.U., K.T., M.O., K.A., R.K., K.O., T.D., T.K., Y.T.I., M.M., K.H., M.Y., T.F., S.U.)
| | - Kouichi Tamura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan (H.W., K.U., K.T., M.O., K.A., R.K., K.O., T.D., T.K., Y.T.I., M.M., K.H., M.Y., T.F., S.U.)
| | - Masato Ohsawa
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan (H.W., K.U., K.T., M.O., K.A., R.K., K.O., T.D., T.K., Y.T.I., M.M., K.H., M.Y., T.F., S.U.)
| | - Kengo Azushima
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan (H.W., K.U., K.T., M.O., K.A., R.K., K.O., T.D., T.K., Y.T.I., M.M., K.H., M.Y., T.F., S.U.)
| | - Ryu Kobayashi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan (H.W., K.U., K.T., M.O., K.A., R.K., K.O., T.D., T.K., Y.T.I., M.M., K.H., M.Y., T.F., S.U.)
| | - Kohji Ohki
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan (H.W., K.U., K.T., M.O., K.A., R.K., K.O., T.D., T.K., Y.T.I., M.M., K.H., M.Y., T.F., S.U.)
| | - Toru Dejima
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan (H.W., K.U., K.T., M.O., K.A., R.K., K.O., T.D., T.K., Y.T.I., M.M., K.H., M.Y., T.F., S.U.)
| | - Tomohiko Kanaoka
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan (H.W., K.U., K.T., M.O., K.A., R.K., K.O., T.D., T.K., Y.T.I., M.M., K.H., M.Y., T.F., S.U.)
| | - Yuko Tsurumi-Ikeya
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan (H.W., K.U., K.T., M.O., K.A., R.K., K.O., T.D., T.K., Y.T.I., M.M., K.H., M.Y., T.F., S.U.)
| | - Miyuki Matsuda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan (H.W., K.U., K.T., M.O., K.A., R.K., K.O., T.D., T.K., Y.T.I., M.M., K.H., M.Y., T.F., S.U.)
| | - Kotaro Haruhara
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan (H.W., K.U., K.T., M.O., K.A., R.K., K.O., T.D., T.K., Y.T.I., M.M., K.H., M.Y., T.F., S.U.)
| | - Akira Nishiyama
- Department of Pharmacology, Kagawa University School of Medicine, Kagawa, Japan (A.N.)
| | - Machiko Yabana
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan (H.W., K.U., K.T., M.O., K.A., R.K., K.O., T.D., T.K., Y.T.I., M.M., K.H., M.Y., T.F., S.U.)
| | - Tetsuya Fujikawa
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan (H.W., K.U., K.T., M.O., K.A., R.K., K.O., T.D., T.K., Y.T.I., M.M., K.H., M.Y., T.F., S.U.)
| | - Akio Yamashita
- Department of Molecular Biology, Yokohama City University Graduate School of Medicine, Yokohama, Japan (A.Y.)
| | - Satoshi Umemura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan (H.W., K.U., K.T., M.O., K.A., R.K., K.O., T.D., T.K., Y.T.I., M.M., K.H., M.Y., T.F., S.U.)
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Verouti SN, Boscardin E, Hummler E, Frateschi S. Regulation of blood pressure and renal function by NCC and ENaC: lessons from genetically engineered mice. Curr Opin Pharmacol 2015; 21:60-72. [PMID: 25613995 DOI: 10.1016/j.coph.2014.12.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 12/22/2014] [Accepted: 12/22/2014] [Indexed: 01/01/2023]
Abstract
The activity of the thiazide-sensitive Na(+)/Cl(-) cotransporter (NCC) and of the amiloride-sensitive epithelial Na(+) channel (ENaC) is pivotal for blood pressure regulation. NCC is responsible for Na(+) reabsorption in the distal convoluted tubule (DCT) of the nephron, while ENaC reabsorbs the filtered Na(+) in the late DCT and in the cortical collecting ducts (CCD) providing the final renal adjustment to Na(+) balance. Here, we aim to highlight the recent advances made using transgenic mouse models towards the understanding of the regulation of NCC and ENaC function relevant to the control of sodium balance and blood pressure. We thus like to pave the way for common mechanisms regulating these two sodium-transporting proteins and their potential implication in structural remodeling of the nephron segments and Na(+) and Cl(-) reabsorption.
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Affiliation(s)
- Sophia N Verouti
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Emilie Boscardin
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Edith Hummler
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland.
| | - Simona Frateschi
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland.
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Haruhara K, Tsuboi N, Koike K, Fukui A, Miyazaki Y, Kawamura T, Ogura M, Yokoo T. Renal histopathological findings in relation to ambulatory blood pressure in chronic kidney disease patients. Hypertens Res 2014; 38:116-22. [PMID: 25231252 DOI: 10.1038/hr.2014.140] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 07/30/2014] [Accepted: 08/05/2014] [Indexed: 11/09/2022]
Abstract
Recent studies have demonstrated that ambulatory blood pressure monitoring is useful for predicting the long-term renal prognosis and future cardiovascular events in chronic kidney disease patients. Currently, however, information is limited regarding the relationships between individual renal histopathological findings and abnormalities in ambulatory blood pressure. This retrospective cross-sectional study included a total of 138 patients, in whom both renal biopsies and ambulatory blood pressure monitoring were performed during the same admission period. Renal histopathological findings, including global glomerulosclerosis, interstitial fibrosis/tubular atrophy and the presence of arterial lesions and arteriole lesions, were scored and analyzed in relation to the ambulatory blood pressure values. Among these histopathological characteristics, only the severity of interstitial fibrosis/tubular atrophy exhibited a significant association with an increased mean value of daytime and nighttime blood pressure. However, the remaining histopathological features showed only trends or weak relationships with these values. In addition, a moderately advanced grade of interstitial fibrosis/tubular atrophy was found to be significantly associated with both daytime and nighttime hypertension, independent of the kidney function, overt proteinuria and the use of antihypertensive medications, according to multivariate analyses. Furthermore, the night-to-day ratio of the mean blood pressure displayed a significant increasing trend according to the grade of interstitial fibrosis/tubular atrophy. These results suggest that interstitial fibrosis/tubular atrophy is the most relevant renal histopathological parameter associated with abnormalities in ambulatory blood pressure, including nocturnal hypertension, in this population.
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Affiliation(s)
- Kotaro Haruhara
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Nobuo Tsuboi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kentaro Koike
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Akira Fukui
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Yoichi Miyazaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Tetsuya Kawamura
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Makoto Ogura
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
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Effects of the Angiotensin receptor blocker olmesartan on adipocyte hypertrophy and function in mice with metabolic disorders. BIOMED RESEARCH INTERNATIONAL 2014; 2014:946492. [PMID: 24991574 PMCID: PMC4060760 DOI: 10.1155/2014/946492] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 05/10/2014] [Accepted: 05/10/2014] [Indexed: 02/06/2023]
Abstract
In the present study, we examined the therapeutic effects of olmesartan, an angiotensin II (Ang II) type 1 receptor (AT1R)-specific blocker, in genetically obese diabetic KKAy mice, a model of human metabolic disorders with visceral obesity, with a focus on an olmesartan effect on the adipose tissue. Olmesartan treatment (3 mg/kg per day) for 4 weeks significantly lowered systolic blood pressure but did not affect body weight during the study period in KKAy mice. However, there were three interesting findings possibly related to the pleiotropic effects of olmesartan on adipose tissue in KKAy mice: (1) an inhibitory effect on adipocyte hypertrophy, (2) a suppressive effect on IL-6 gene expression, and (3) an ameliorating effect on oxidative stress. On the other hand, olmesartan exerted no evident influence on the adipose tissue expression of AT1R-associated protein (ATRAP), which is a molecule interacting with AT1R so as to inhibit pathological AT1R activation and is suggested to be an emerging molecular target in metabolic disorders with visceral obesity. Collectively, these results suggest that the blood pressure lowering effect of olmesartan in KKAy mice is associated with an improvement in adipocyte, including suppression of adipocyte hypertrophy and inhibition of the adipose IL-6-oxidative stress axis. Further study is needed to clarify the functional role of adipose ATRAP in the pleiotropic effects of olmesartan.
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Ohsawa M, Tamura K, Wakui H, Maeda A, Dejima T, Kanaoka T, Azushima K, Uneda K, Tsurumi-Ikeya Y, Kobayashi R, Matsuda M, Uchida S, Toya Y, Kobori H, Nishiyama A, Yamashita A, Ishikawa Y, Umemura S. Deletion of the angiotensin II type 1 receptor-associated protein enhances renal sodium reabsorption and exacerbates angiotensin II-mediated hypertension. Kidney Int 2014; 86:570-81. [PMID: 24694992 PMCID: PMC4149871 DOI: 10.1038/ki.2014.95] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 02/07/2014] [Accepted: 02/13/2014] [Indexed: 12/13/2022]
Abstract
Angiotensin II type 1 receptor (AT1R)–associated protein (ATRAP) promotes AT1R internalization along with suppression of pathological activation of tissue AT1R signaling. However, the functional significance of ATRAP in renal sodium handling and blood pressure regulation under pathological stimuli is not fully resolved. Here we show the blood pressure of mice with a gene-targeted disruption of ATRAP was comparable to that of wild-type mice at baseline. However, in ATRAP-knockout mice, angiotensin II–induced hypertension was exacerbated and the extent of positive sodium balance was increased by angiotensin II. Renal expression of the sodium-proton antiporter 3, a major sodium transporter in the proximal tubules, urinary pH, renal angiotensinogen production, and angiotensin II content was unaffected. Stimulation of the renal expression and activity of the epithelial sodium channel (ENaC), a major sodium transporter in the distal tubules, was significantly enhanced by chronic angiotensin II infusion. The circulating and urinary aldosterone levels were comparable. The blood pressure response and renal ENaC expression by aldosterone were not affected. Thus, ATRAP deficiency exacerbated angiotensin II–mediated hypertension by pathological activation of renal tubular AT1R by angiotensin II. This directly stimulates ENaC in the distal tubules and enhances sodium retention in an aldosterone-independent manner.
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Affiliation(s)
- Masato Ohsawa
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kouichi Tamura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Hiromichi Wakui
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Akinobu Maeda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Toru Dejima
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomohiko Kanaoka
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kengo Azushima
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Kazushi Uneda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Yuko Tsurumi-Ikeya
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Ryu Kobayashi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Miyuki Matsuda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Shinichi Uchida
- Department of Nephrology, Graduate School of Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yoshiyuki Toya
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Hiroyuki Kobori
- Department of Pharmacology, Kagawa University School of Medicine, Kagawa, Japan
| | - Akira Nishiyama
- Department of Pharmacology, Kagawa University School of Medicine, Kagawa, Japan
| | - Akio Yamashita
- Department of Molecular Biology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Yoshihiro Ishikawa
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Satoshi Umemura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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Maeda A, Tamura K, Wakui H, Ohsawa M, Azushima K, Uneda K, Kobayashi R, Tsurumi-Ikeya Y, Kanaoka T, Dejima T, Ohki K, Haku S, Yamashita A, Umemura S. Effects of Ang II receptor blocker irbesartan on adipose tissue function in mice with metabolic disorders. Int J Med Sci 2014; 11:646-51. [PMID: 24834011 PMCID: PMC4021097 DOI: 10.7150/ijms.8577] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 03/31/2014] [Indexed: 12/24/2022] Open
Abstract
Recent studies indicate that the functional renin-angiotensin system (RAS) exists in the adipose tissue. The adipose tissue RAS is proposed in the pathophysiology of metabolic disorders. In the present study, we examined therapeutic effects of irbesartan, an angiotensin II (Ang II) type 1 receptor (AT1R)-specific blocker, in genetically obese diabetic KKAy mice, a model of human metabolic disorders without any dietary loading, with our focus on the analysis on possible effect of irbesartan on the adipose tissue. The treatment with irbesartan significantly lowered systolic blood pressure with a concomitant decrease in body weight in KKAy mice. In addition, irbesartan significantly decreased the adipose leptin mRNA expression and tended to decrease IL-6 mRNA expression in the adipose tissue of KKAy mice. Furthermore irbesartan preserved the adipose gene expression of AT1R-associated protein (ATRAP), an endogenous inhibitory molecule of tissue AT1R signaling, with a concomitant tendency of up-regulation of adipose tissue ATRAP/AT1R ratio. Collectively, these results suggest that the irbesartan-induced beneficial suppressive effect on the leptin-IL-6 axis in the adipose tissue in KKAy mice is partly mediated by a trend of up-regulation of the adipose ATRAP/AT1R ratio as one of pleiotropic effects of irbesartan.
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Affiliation(s)
- Akinobu Maeda
- 1. Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate Scholl of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Kouichi Tamura
- 1. Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate Scholl of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Hiromichi Wakui
- 1. Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate Scholl of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Masato Ohsawa
- 1. Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate Scholl of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Kengo Azushima
- 1. Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate Scholl of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Kazushi Uneda
- 1. Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate Scholl of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Ryu Kobayashi
- 1. Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate Scholl of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Yuko Tsurumi-Ikeya
- 1. Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate Scholl of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Tomohiko Kanaoka
- 1. Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate Scholl of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Toru Dejima
- 1. Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate Scholl of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Koji Ohki
- 1. Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate Scholl of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Sona Haku
- 1. Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate Scholl of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Akio Yamashita
- 2. Department of Molecular Biology, Yokohama City University Graduate Scholl of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Satoshi Umemura
- 1. Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate Scholl of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
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Flister MJ, Tsaih SW, O'Meara CC, Endres B, Hoffman MJ, Geurts AM, Dwinell MR, Lazar J, Jacob HJ, Moreno C. Identifying multiple causative genes at a single GWAS locus. Genome Res 2013; 23:1996-2002. [PMID: 24006081 PMCID: PMC3847770 DOI: 10.1101/gr.160283.113] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Accepted: 09/03/2013] [Indexed: 01/11/2023]
Abstract
Genome-wide association studies (GWAS) are useful for nominating candidate genes, but typically are unable to establish disease causality or differentiate between the effects of variants in linkage disequilibrium (LD). Additionally, some GWAS loci might contain multiple causative variants or genes that contribute to the overall disease susceptibility at a single locus. However, the majority of current GWAS lack the statistical power to test whether multiple causative genes underlie the same locus, prompting us to adopt an alternative approach to testing multiple GWAS genes empirically. We used gene targeting in a disease-susceptible rat model of genetic hypertension to test all six genes at the Agtrap-Plod1 locus (Agtrap, Mthfr, Clcn6, Nppa, Nppb, and Plod1) for blood pressure (BP) and renal phenotypes. This revealed that the majority of genes at this locus (five out of six) can impact hypertension by modifying BP and renal phenotypes. Mutations of Nppa, Plod1, and Mthfr increased disease susceptibility, whereas Agtrap and Clcn6 mutations decreased hypertension risk. Reanalysis of the human AGTRAP-PLOD1 locus also implied that disease-associated haplotype blocks with polygenic effects were not only possible, but rather were highly plausible. Combined, these data demonstrate for the first time that multiple modifiers of hypertension can cosegregate at a single GWAS locus.
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Affiliation(s)
- Michael J. Flister
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
| | - Shirng-Wern Tsaih
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
| | - Caitlin C. O'Meara
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Bradley Endres
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
| | - Matthew J. Hoffman
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
| | - Aron M. Geurts
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
| | - Melinda R. Dwinell
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
| | - Jozef Lazar
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
- Department of Dermatology
| | - Howard J. Jacob
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
| | - Carol Moreno
- Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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Gonzalez-Vicente A, Garvin JL. Angiotensin II-induced hypertension increases plasma membrane Na pump activity by enhancing Na entry in rat thick ascending limbs. Am J Physiol Renal Physiol 2013; 305:F1306-14. [PMID: 23986517 DOI: 10.1152/ajprenal.00064.2013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Thick ascending limbs (TAL) reabsorb 30% of the filtered NaCl load. Na enters the cells via apical Na-K-2Cl cotransporters and Na/H exchangers and exits via basolateral Na pumps. Chronic angiotensin II (ANG II) infusion increases net TAL Na transport and Na apical entry; however, little is known about its effects on the basolateral Na pump. We hypothesized that in rat TALs Na pump activity is enhanced by ANG II-infusion, a model of ANG II-induced hypertension. Rats were infused with 200 ng·kg(-1)·min(-1) ANG II or vehicle for 7 days, and TAL suspensions were obtained. We studied plasma membrane Na pump activity by measuring changes in 1) intracellular Na (Nai) induced by ouabain; and 2) ouabain-sensitive oxygen consumption (QO2). We found that the ouabain-sensitive rise in Nai in TALs from ANG II-infused rats was 12.8 ± 0.4 arbitrary fluorescent units (AFU)·mg(-1)·min(-1) compared with only 9.9 ± 1.1 AFU·mg(-1)·min(-1) in controls (P < 0.024). Ouabain-sensitive oxygen consumption was 17 ± 5% (P < 0.043) greater in tubules from ANG II-treated than vehicle rats. ANG II infusion did not alter total Na pump expression, the number of Na pumps in the plasma membrane, or the affinity for Na. When furosemide (1.1 mg·kg(-1)·day(-1)) was coinfused with ANG II, no increase in plasma membrane Na pump activity was observed. We concluded that in ANG II-induced hypertension Na pump activity is increased in the plasma membrane of TALs and that this increase is caused by the chronically enhanced Na entry occurring in this model.
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Affiliation(s)
- Agustin Gonzalez-Vicente
- Dept. of Physiology and Biophysics, Case Western Reserve Univ. School of Medicine, 10900 Euclid Ave, MS 4970, Robbins-E-526, Cleveland, OH 44106-4970.
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Giani JF, Fuchs S, Gonzalez-Villalobos RA. Angiotensin II type 1 receptor-associated protein: a novel modulator of angiotensin II actions in the nephron. Hypertension 2013; 61:1150-2. [PMID: 23529171 DOI: 10.1161/hypertensionaha.113.01150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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