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Liu B, Hu Y, Tian D, Dong J, Li BF. Assessing the effects of tempol on renal fibrosis, inflammation, and oxidative stress in a high-salt diet combined with 5/6 nephrectomy rat model: utilizing oxidized albumin as a biomarker. BMC Nephrol 2024; 25:64. [PMID: 38395806 PMCID: PMC10893674 DOI: 10.1186/s12882-024-03495-0] [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: 11/14/2023] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
BACKGROUND Oxidative stress has been implicated in the pathogenesis of chronic kidney disease (CKD), prompting the exploration of antioxidants as a potential therapeutic avenue for mitigating disease progression. This study aims to investigate the beneficial impact of Tempol on the progression of CKD in a rat model utilizing oxidized albumin as a biomarker. METHODS After four weeks of treatment, metabolic parameters, including body weight, left ventricle residual weight, kidney weight, urine volume, and water and food intake, were measured. Systolic blood pressure, urinary protein, oxidized albumin level, serum creatinine (Scr), blood urea nitrogen (BUN), 8-OHdG, TGF-β1, and micro-albumin were also assessed. Renal fibrosis was evaluated through histological and biochemical assays. P65-NF-κB was quantified using an immunofluorescence test, while Smad3, P65-NF-κB, and Collagen I were measured using western blot. TNF-α, IL-6, MCP-1, TGF-β1, Smad3, and P65-NF-κB were analyzed by RT-qPCR. RESULTS Rats in the high-salt diet group exhibited impaired renal function, characterized by elevated levels of blood urea nitrogen, serum creatinine, 8-OHdG, urine albumin, and tubulointerstitial damage, along with reduced body weight. However, these effects were significantly ameliorated by Tempol administration. In the high-salt diet group, blood pressure, urinary protein, and oxidized albumin levels were notably higher compared to the normal diet group, but Tempol administration in the treatment group reversed these effects. Rats in the high-salt diet group also displayed increased levels of proinflammatory factors (TNF-α, IL-6, MCP1) and profibrotic factors (NF-κB activation, Collagen I), elevated expression of NADPH oxidation-related subunits (P65), and activation of the TGF-β1/Smad3 signaling pathway. Tempol treatment inhibited NF-κB-mediated inflammation and TGF-β1/Smad3-induced renal fibrosis signaling pathway activation. CONCLUSION These findings suggest that Tempol may hold therapeutic potential for preventing and treating rats undergoing 5/6 nephrectomy. Further research is warranted to elucidate the mechanisms underlying Tempol's protective effects and its potential clinical applications. Besides, there is a discernible positive relationship between oxidized albumin and other biomarkers, such as 8-OHG, urinary protein levels, mALB, Scr, BUN, and TGF-β1 in a High-salt diet combined with 5/6 nephrectomy rat model. These findings suggest the potential utility of oxidized albumin as a sensitive indicator for oxidative stress assessment.
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Affiliation(s)
- Beibei Liu
- College of Life and Health, Nanjing Polytechnic Institute, No.188 Xinle Road, Luhe District, 210048, Nanjing, Nanjing, Jiangsu, China
| | - Yanling Hu
- College of Life and Health, Nanjing Polytechnic Institute, No.188 Xinle Road, Luhe District, 210048, Nanjing, Nanjing, Jiangsu, China
| | - Danyang Tian
- Department of Physiology, Hebei Medical University, Shijiazhuang, China
| | - Jianlong Dong
- Hebei University of Chinese Medicine, The First Affiliated Hospital, Shijiazhuang, China
| | - Bing-Feng Li
- College of Life and Health, Nanjing Polytechnic Institute, No.188 Xinle Road, Luhe District, 210048, Nanjing, Nanjing, Jiangsu, China.
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Simões E Silva AC, Oliveira EA, Cheung WW, Mak RH. Redox Signaling in Chronic Kidney Disease-Associated Cachexia. Antioxidants (Basel) 2023; 12:antiox12040945. [PMID: 37107320 PMCID: PMC10136196 DOI: 10.3390/antiox12040945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/14/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023] Open
Abstract
Redox signaling alterations contribute to chronic kidney disease (CKD)-associated cachexia. This review aims to summarize studies about redox pathophysiology in CKD-associated cachexia and muscle wasting and to discuss potential therapeutic approaches based on antioxidant and anti-inflammatory molecules to restore redox homeostasis. Enzymatic and non-enzymatic systems of antioxidant molecules have been studied in experimental models of kidney diseases and patients with CKD. Oxidative stress is increased by several factors present in CKD, including uremic toxins, inflammation, and metabolic and hormone alterations, leading to muscle wasting. Rehabilitative nutritional and physical exercises have shown beneficial effects for CKD-associated cachexia. Anti-inflammatory molecules have also been tested in experimental models of CKD. The importance of oxidative stress has been shown by experimental studies in which antioxidant therapies ameliorated CKD and its associated complications in the 5/6 nephrectomy model. Treatment of CKD-associated cachexia is a challenge and further studies are necessary to investigate potential therapies involving antioxidant therapy.
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Affiliation(s)
- Ana Cristina Simões E Silva
- Department of Pediatrics, Division of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte 30130-100, MG, Brazil
| | - Eduardo A Oliveira
- Department of Pediatrics, Division of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte 30130-100, MG, Brazil
| | - Wai W Cheung
- Department of Pediatrics, Rady Children's Hospital San Diego, University of California San Diego, La Jolla, CA 92093, USA
| | - Robert H Mak
- Department of Pediatrics, Rady Children's Hospital San Diego, University of California San Diego, La Jolla, CA 92093, USA
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Molinari P, Caldiroli L, Dozio E, Rigolini R, Giubbilini P, Romanelli MMC, Messa P, Vettoretti S. AGEs and sRAGE Variations at Different Timepoints in Patients with Chronic Kidney Disease. Antioxidants (Basel) 2021; 10:antiox10121994. [PMID: 34943097 PMCID: PMC8698924 DOI: 10.3390/antiox10121994] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/10/2021] [Accepted: 12/12/2021] [Indexed: 12/22/2022] Open
Abstract
Patients with chronic kidney disease (CKD) are affected by enhanced oxidative stress and chronic inflammation, and these factors may contribute to increase advanced glycation end-products (AGEs). In this study we quantified AGEs and soluble receptors for AGE (sRAGE) isoforms and evaluated the association between their variations and eGFR at baseline and after 12 months. We evaluated 64 patients. AGEs were quantified by fluorescence intensity using a fluorescence spectrophotometer, and sRAGE by ELISA. Median age was 81 years, male patients accounted for 70%, 63% were diabetic, and eGFR was 27 ± 10 mL/min/1.73 m2. At follow up, sRAGE isoforms underwent a significant decrement (1679 [1393;2038] vs. 1442 [1117;2102], p < 0.0001), while AGEs/sRAGE ratios were increased (1.77 ± 0.92 vs. 2.24 ± 1.34, p = 0.004). Although AGEs and AGEs/sRAGE ratios were inversely related with eGFR, their basal values as well their variations did not show a significant association with eGFR changes. In a cohort of patients with a stable clinical condition at 1 year follow-up, AGEs/sRAGE was associated with renal function. The lack of association with eGFR suggests that other factors can influence its increase. In conclusion, AGEs/sRAGE can be an additional risk factor for CKD progression over a longer time, but its role as a prognostic tool needs further investigation.
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Affiliation(s)
- Paolo Molinari
- Unit of Nephrology, Dialysis and Kidney Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico di Milano, 20122 Milan, Italy; (P.M.); (L.C.); (P.M.)
| | - Lara Caldiroli
- Unit of Nephrology, Dialysis and Kidney Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico di Milano, 20122 Milan, Italy; (P.M.); (L.C.); (P.M.)
| | - Elena Dozio
- Laboratory of Clinical Pathology, Department of Biomedical Science for Health, Università degli Studi di Milano, 20133 Milan, Italy; (E.D.); (M.M.C.R.)
| | - Roberta Rigolini
- Service of Laboratory Medicine1-Clinical Pathology, IRCCS Policlinico San Donato, San Donato Milanese, 20097 Milan, Italy; (R.R.); (P.G.)
| | - Paola Giubbilini
- Service of Laboratory Medicine1-Clinical Pathology, IRCCS Policlinico San Donato, San Donato Milanese, 20097 Milan, Italy; (R.R.); (P.G.)
| | - Massimiliano M. Corsi Romanelli
- Laboratory of Clinical Pathology, Department of Biomedical Science for Health, Università degli Studi di Milano, 20133 Milan, Italy; (E.D.); (M.M.C.R.)
- Service of Laboratory Medicine1-Clinical Pathology, IRCCS Policlinico San Donato, San Donato Milanese, 20097 Milan, Italy; (R.R.); (P.G.)
| | - Piergiorgio Messa
- Unit of Nephrology, Dialysis and Kidney Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico di Milano, 20122 Milan, Italy; (P.M.); (L.C.); (P.M.)
- Department of Clinical Sciences and Community Health, Università degli Studi di Milano, 20122 Milan, Italy
| | - Simone Vettoretti
- Unit of Nephrology, Dialysis and Kidney Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico di Milano, 20122 Milan, Italy; (P.M.); (L.C.); (P.M.)
- Correspondence: ; Tel.: +39-02-55-03-45-52
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4
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Suh SH, Mathew AP, Choi HS, Vasukutty A, Kim CS, Kim IJ, Ma SK, Kim SW, Park IK, Bae EH. Kidney-accumulating olmesartan-loaded nanomicelles ameliorate the organ damage in a murine model of Alport syndrome. Int J Pharm 2021; 600:120497. [PMID: 33753165 DOI: 10.1016/j.ijpharm.2021.120497] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 03/03/2021] [Accepted: 03/12/2021] [Indexed: 12/14/2022]
Abstract
ACE inhibitors or angiotensin II receptor blockers (ACEi/ARBs) have been a cornerstone of the management in kidney disease, but their use is often limited by undesired systemic effects, such as symptomatic hypotension. To minimize the extra-renal effects of ACEi/ARBs, we formulated hydrophobically modified glycol chitosan (HGC) nanomicelles releasing olmesartan (HGC-Olm) that specifically accumulated in the kidney, and investigated whether kidney-specific delivery of olmesartan by HGC nanomicelles could ameliorate organ damage in Col4a3-/- mouse, a murine model of progressive chronic kidney disease mimicking human Alport syndrome. Ex vivo tracing demonstrated that intravenously injected HGC-Olm nanomicelles were specifically delivered to the kidney, with sustained release of olmesartan for more than 48 h. Contrary to the conventional delivery of olmesartan via oral route, injection of HGC-Olm nanomicelles did not alter blood pressure in Col4a3-/- mice. Immunohistochemistry revealed that HGC nanomicelles were diffusely distributed from the cortex and glomeruli to the outer medulla, sparing the inner medulla. Phenotypic analysis showed that the attenuation of kidney fibrosis in the kidney of Col4a3-/- mice by HGC-Olm nanomicelles was comparable to that noted with conventionally delivered olmesartan. Therefore, our results suggest that HGC-Olm nanomicelles could be a safe and effective alternative drug delivery system for kidney diseases.
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Affiliation(s)
- Sang Heon Suh
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Ansuja Pulickal Mathew
- Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Hong Sang Choi
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Arathy Vasukutty
- Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Chang Seong Kim
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - In Jin Kim
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Seong Kwon Ma
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Soo Wan Kim
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - In-Kyu Park
- Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju, Republic of Korea.
| | - Eun Hui Bae
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea.
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6
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Sogawa Y, Nagasu H, Itano S, Kidokoro K, Taniguchi S, Takahashi M, Kadoya H, Satoh M, Sasaki T, Kashihara N. The eNOS-NO pathway attenuates kidney dysfunction via suppression of inflammasome activation in aldosterone-induced renal injury model mice. PLoS One 2018; 13:e0203823. [PMID: 30281670 PMCID: PMC6169882 DOI: 10.1371/journal.pone.0203823] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 08/28/2018] [Indexed: 12/22/2022] Open
Abstract
Hypertension causes vascular complications, such as stroke, cardiovascular disease, and chronic kidney disease (CKD). The relationship between endothelial dysfunction and progression of kidney disease is well known. However, the relationship between the eNOS-NO pathway and chronic inflammation, which is a common pathway for the progression of kidney disease, remains unexplored. We performed in vivo experiments to determine the role of the eNOS-NO pathway by using eNOS-deficient mice in a hypertensive kidney disease model. All mice were unilateral nephrectomized (Nx). One week after Nx, the mice were randomly divided into two groups: the aldosterone infusion groups and the vehicle groups. All mice also received a 1% NaCl solution instead of drinking water. The aldosterone infusion groups were treated with hydralazine to correct blood pressure differences. After four weeks of drug administration, all mice were euthanized, and blood and kidney tissue samples were collected. In the results, NLRP3 inflammasome activation was elevated in the kidneys of the eNOS-deficient mice, and tubulointerstitial fibrosis was accelerated. Suppression of inflammasome activation by knocking out ASC prevented tubulointerstitial injury in the eNOS knockout mice, indicating that the eNOS-NO pathway is involved in the development of kidney dysfunction through acceleration of NLRP3 inflammasome in macrophages. We revealed that endothelial function, particularly the eNOS-NO pathway, attenuates the progression of renal tubulointerstitial injury via suppression of inflammasome activation. Clinically, patients who develop vascular endothelial dysfunction have lifestyle diseases, such as hypertension or diabetes, and are known to be at risk for CKD. Our study suggests that the eNOS-NO pathway could be a therapeutic target for the treatment of chronic kidney disease associated with endothelial dysfunction.
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MESH Headings
- Aldosterone/pharmacology
- Animals
- Antihypertensive Agents/administration & dosage
- Disease Models, Animal
- Endothelium/pathology
- Endothelium/physiopathology
- Fibrosis
- Humans
- Hydralazine/administration & dosage
- Hypertension/complications
- Hypertension/metabolism
- Hypertension, Renal/drug therapy
- Hypertension, Renal/metabolism
- Hypertension, Renal/pathology
- Inflammasomes/drug effects
- Inflammasomes/metabolism
- Kidney/pathology
- Macrophages/drug effects
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Molecular Targeted Therapy
- NLR Family, Pyrin Domain-Containing 3 Protein/genetics
- Nitric Oxide/metabolism
- Nitric Oxide Synthase Type III/genetics
- Nitric Oxide Synthase Type III/metabolism
- Primary Cell Culture
- Renal Insufficiency, Chronic/chemically induced
- Renal Insufficiency, Chronic/etiology
- Renal Insufficiency, Chronic/metabolism
- Renal Insufficiency, Chronic/pathology
- Vasodilator Agents/administration & dosage
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Affiliation(s)
- Yuji Sogawa
- Department of Nephrology and Hypertension Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Hajime Nagasu
- Department of Nephrology and Hypertension Kawasaki Medical School, Kurashiki, Okayama, Japan
- * E-mail:
| | - Seiji Itano
- Department of Nephrology and Hypertension Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Kengo Kidokoro
- Department of Nephrology and Hypertension Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Shun’ichiro Taniguchi
- Department of Molecular Oncology, Shinshu University Graduate School of Medicine, Matsumoto, Nagano, Japan
| | - Masafumi Takahashi
- Division of Inflammation Research, Center for Molecular Medicine, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | - Hiroyuki Kadoya
- Department of Nephrology and Hypertension Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Minoru Satoh
- Department of Nephrology and Hypertension Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Tamaki Sasaki
- Department of Nephrology and Hypertension Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Naoki Kashihara
- Department of Nephrology and Hypertension Kawasaki Medical School, Kurashiki, Okayama, Japan
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7
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Abstract
SIGNIFICANCE A common link between all forms of acute and chronic kidney injuries, regardless of species, is enhanced generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) during injury/disease progression. While low levels of ROS and RNS are required for prosurvival signaling, cell proliferation and growth, and vasoreactivity regulation, an imbalance of ROS and RNS generation and elimination leads to inflammation, cell death, tissue damage, and disease/injury progression. RECENT ADVANCES Many aspects of renal oxidative stress still require investigation, including clarification of the mechanisms which prompt ROS/RNS generation and subsequent renal damage. However, we currently have a basic understanding of the major features of oxidative stress pathology and its link to kidney injury/disease, which this review summarizes. CRITICAL ISSUES The review summarizes the critical sources of oxidative stress in the kidney during injury/disease, including generation of ROS and RNS from mitochondria, NADPH oxidase, and inducible nitric oxide synthase. The review next summarizes the renal antioxidant systems that protect against oxidative stress, including superoxide dismutase and catalase, the glutathione and thioredoxin systems, and others. Next, we describe how oxidative stress affects kidney function and promotes damage in every nephron segment, including the renal vessels, glomeruli, and tubules. FUTURE DIRECTIONS Despite the limited success associated with the application of antioxidants for treatment of kidney injury/disease thus far, preventing the generation and accumulation of ROS and RNS provides an ideal target for potential therapeutic treatments. The review discusses the shortcomings of antioxidant treatments previously used and the potential promise of new ones. Antioxid. Redox Signal. 25, 119-146.
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Affiliation(s)
- Brian B Ratliff
- 1 Department of Medicine, Renal Research Institute , New York Medical College, Valhalla, New York.,2 Department of Physiology, Renal Research Institute , New York Medical College, Valhalla, New York
| | - Wasan Abdulmahdi
- 2 Department of Physiology, Renal Research Institute , New York Medical College, Valhalla, New York
| | - Rahul Pawar
- 1 Department of Medicine, Renal Research Institute , New York Medical College, Valhalla, New York
| | - Michael S Wolin
- 2 Department of Physiology, Renal Research Institute , New York Medical College, Valhalla, New York
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Sharaf El-Din AAI, Abd Allah OM. Impact of Olmesartan Medoxomil on Amiodarone-Induced Pulmonary Toxicity in Rats: Focus on Transforming Growth Factor-ß1. Basic Clin Pharmacol Toxicol 2016; 119:58-67. [DOI: 10.1111/bcpt.12551] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Accepted: 12/23/2015] [Indexed: 12/18/2022]
Affiliation(s)
| | - Omaima M. Abd Allah
- Department of Pharmacology and Therapeutics; Faculty of Medicine; Benha University; Benha Egypt
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9
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Hubens LEG, Verloop WL, Joles JA, Blankestijn PJ, Voskuil M. Ischemia and reactive oxygen species in sympathetic hyperactivity states: a vicious cycle that can be interrupted by renal denervation? Curr Hypertens Rep 2014; 15:313-20. [PMID: 23754326 DOI: 10.1007/s11906-013-0367-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Renal denervation has developed as a new treatment strategy for patients suffering from resistant hypertension. The success of this therapy is due to the fact that sympathetic hyperactivity is involved in the pathogenesis of elevated blood pressure. However, not only the sympathetic nervous system (SNS), but also the renin angiotensin system (RAS) is known to be involved in hypertension. In addition, RAS is involved in other sympathetic hyperactivity states, such as heart failure, chronic kidney disease, insulin resistance and obstructive sleep apnea. Moreover, renal denervation has a beneficial effect on patients suffering from these disease states. Recent research suggested that the production of reactive oxygen species (ROS) is elevated in sympathetic hyperactivity states, and that ROS are able to activate the SNS and local tissue renin angiotensin system. Therefore, this review discusses the possibility of ROS as a common trigger of SNS and RAS activity in sympathetic hyperactivity states, and the effect of renal denervation on this ROS production.
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Affiliation(s)
- Lisette E G Hubens
- Division of Heart and Lungs, Department of Cardiology, University Medical Center Utrecht, Heidelberglaan 100, Utrecht, The Netherlands
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10
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Abstract
SIGNIFICANCE Renal oxidative stress can be a cause, a consequence, or more often a potentiating factor for hypertension. Increased reactive oxygen species (ROS) in the kidney have been reported in multiple models of hypertension and related to renal vasoconstriction and alterations of renal function. Nicotinamide adenine dinucleotide phosphate oxidase is the central source of ROS in the hypertensive kidney, but a defective antioxidant system also can contribute. RECENT ADVANCES Superoxide has been identified as the principal ROS implicated for vascular and tubular dysfunction, but hydrogen peroxide (H2O2) has been implicated in diminishing preglomerular vascular reactivity, and promoting medullary blood flow and pressure natriuresis in hypertensive animals. CRITICAL ISSUES AND FUTURE DIRECTIONS Increased renal ROS have been implicated in renal vasoconstriction, renin release, activation of renal afferent nerves, augmented contraction, and myogenic responses of afferent arterioles, enhanced tubuloglomerular feedback, dysfunction of glomerular cells, and proteinuria. Inhibition of ROS with antioxidants, superoxide dismutase mimetics, or blockers of the renin-angiotensin-aldosterone system or genetic deletion of one of the components of the signaling cascade often attenuates or delays the onset of hypertension and preserves the renal structure and function. Novel approaches are required to dampen the renal oxidative stress pathways to reduced O2(-•) rather than H2O2 selectivity and/or to enhance the endogenous antioxidant pathways to susceptible subjects to prevent the development and renal-damaging effects of hypertension.
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Affiliation(s)
- Magali Araujo
- Hypertension, Kidney and Vascular Research Center, Georgetown University , Washington, District of Columbia
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11
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Angiotensin II reduces transport-dependent oxygen consumption but increases transport-independent oxygen consumption in immortalized mouse proximal tubular cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 812:157-163. [PMID: 24729228 DOI: 10.1007/978-1-4939-0620-8_21] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Oxidative stress is closely associated with renal dysfunction following diabetes and hypertension. Angiotensin II (Ang II) can activate the NADPH-oxidase, increasing oxidative stress that is thought to blunt proximal tubular electrolyte transport and thereby oxygen consumption (QO₂). We investigated the effect of Ang II on QO₂ in immortalized mouse proximal tubular cells over-expressing the NADPH oxidase subunit p22(phox); a model of increased oxidative stress. Cultured cells were exposed to either Ang II or H₂O₂ for 48 h. QO₂ was determined during baseline (113 mmol/l NaCl; transport-dependent QO₂) and during sodium-free conditions (transport-independent QO₂). Ang II reduced transport-dependent QO₂ in wild-types, but not in p22(phox) which also displayed increased QO₂ at baseline. Transport-independent QO₂ was increased in p22(phox) and Ang II had no additional effect, whereas it increased QO₂ in wild-type. Addition of H₂O₂ reduced transport-dependent QO₂ in wild-types, but not in p22(phox). Transport-independent QO₂ was unaffected by H₂O₂. The similar effects of Ang II and H₂O₂ to reduce transport-dependent QO₂ suggest a direct regulatory role of oxidative stress. In accordance, the transport-dependent QO₂ was reduced in p22(phox) already during baseline. The effects of Ang II on transport-independent QO₂ was not replicated by H₂O₂, indicating direct regulation via Ang II-receptors independently of oxidative stress. However, the Ang II effect was absent in p22(phox), suggesting that oxidative stress also modulates normal Ang II signaling. In conclusion, Ang II affects both transport-dependent and transport-independent QO₂ in proximal tubular cells and may be an important pathway modulating renal QO₂.
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12
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Si X, Li P, Zhang Y, Zhang Y, Lv W, Qi D. Renoprotective effects of olmesartan medoxomil on diabetic nephropathy in streptozotocin-induced diabetes in rats. Biomed Rep 2014; 2:24-28. [PMID: 24649063 PMCID: PMC3917007 DOI: 10.3892/br.2013.183] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 07/11/2013] [Indexed: 01/13/2023] Open
Abstract
Olmesartan medoxomil (OM) is one of the newest members of the angiotensin receptor blocker (ARB) family. The renoprotective effects of the angiotensin II type 1 receptor antagonist OM was investigated in a streptozotocin (STZ)-induced diabetic rat model. In this study, we investigated whether OM was able to ameliorate diabetic nephropathy (DN). Thirty male Sprague Dawley rats were assigned to 3 groups: the non-diabetic (group A, n=10), the untreated STZ-induced DN control (group B, n=10) and the STZ-induced DN treated with OM (group C, n=10). Blood pressure (BP) and glucose, creatinine (Cr), blood urea nitrogen (BUN), superoxide dismutase (SOD), malondialdehyde (MDA) microalbumin and urinary protein concentrations were measured. In STZ diabetic rats, BP, glucose, Cr, BUN, MDA and urinary protein levels were significantly increased compared to the non-diabetic control group. OM significantly improved the biological indices in the DN rats. The renal pathological changes were also observed under a light microscope. Our results suggested that OM exerted renoprotective effects on rats with STZ-induced diabetes.
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Affiliation(s)
- Xiaofei Si
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, P.R. China
| | - Peng Li
- Yantai Yu Huang Ding Hospital, Yantai, Shandong 264000, P.R. China
| | - Yan Zhang
- Yantai Yu Huang Ding Hospital, Yantai, Shandong 264000, P.R. China
| | - Yan Zhang
- Yantai Hospital of Traditional Chinese Medicine, Yantai, Shandong 264005, P.R. China
| | - Wei Lv
- Yantai Yu Huang Ding Hospital, Yantai, Shandong 264000, P.R. China
| | - Dong Qi
- Yantai Yu Huang Ding Hospital, Yantai, Shandong 264000, P.R. China
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13
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Whiting C, Castillo A, Haque MZ, Majid DSA. Protective role of the endothelial isoform of nitric oxide synthase in ANG II-induced inflammatory responses in the kidney. Am J Physiol Renal Physiol 2013; 305:F1031-41. [PMID: 23926180 DOI: 10.1152/ajprenal.00024.2013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
In the present study, we examine the hypothesis that the nitric oxide (NO) produced by endothelial NO synthase (eNOS) plays a protective role in the development of ANG II-induced hypertension and renal injury by minimizing oxidative stress and the inflammation induced by TNF-α. Systolic blood pressure (SBP) and renal injury responses to chronic infusions of ANG II (via implanted minipumps) were evaluated for 2 wk in wild-type (WT) and in eNOS knockout mice (KO) cotreated with or without a superoxide (O2(-)) scavenger, tempol (400 mg/l in the drinking water), or a TNF-α receptor blocker, etanercept (5 mg/kg/day ip). In study 1, when ANG II was given at a dose of 25 ng/min, it increased mean SBP in WT mice (Δ36 ± 3 mmHg; n = 7), and this effect was attenuated in mice pretreated with tempol (Δ24 ± 3 mmHg; n = 6). In KO mice (n = 9), this dose of ANG II resulted in severe renal injury associated with high mortality. To avoid this high mortality in KO, study 2 was conducted with a lower dose of ANG II (10 ng/min) that increased SBP slightly in WT (Δ17 ± 7 mmHg; n = 6) but exaggeratedly in KO (Δ48 ± 12 mmHg, n = 6) associated with severe renal injury. Cotreatment with either tempol (n = 6) or etanercept (n = 6) ameliorated the hypertensive, as well as the renal injury responses in KO compared with WT. These data demonstrate a protective role for eNOS activity in preventing renal inflammatory injury and hypertension induced by chronic increases in ANG II.
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Affiliation(s)
- Curtis Whiting
- Dept. of Physiology, Hypertension and Renal Center of Excellence, Tulane Univ. Health Sciences Center, New Orleans, LA 70112, USA.
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Nagib MM, Tadros MG, ELSayed MI, Khalifa AE. Anti-inflammatory and anti-oxidant activities of olmesartan medoxomil ameliorate experimental colitis in rats. Toxicol Appl Pharmacol 2013; 271:106-13. [DOI: 10.1016/j.taap.2013.04.026] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 04/27/2013] [Accepted: 04/30/2013] [Indexed: 01/15/2023]
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Olmesartan reduces inflammatory biomarkers in patients with stable coronary artery disease undergoing percutaneous coronary intervention: results from the OLIVUS trial. Heart Vessels 2013; 29:178-85. [DOI: 10.1007/s00380-013-0343-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 03/22/2013] [Indexed: 11/26/2022]
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16
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Li PL, Zhang Y. Cross talk between ceramide and redox signaling: implications for endothelial dysfunction and renal disease. Handb Exp Pharmacol 2013:171-97. [PMID: 23563657 DOI: 10.1007/978-3-7091-1511-4_9] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Recent studies have demonstrated that cross talk between ceramide and redox signaling modulates various cell activities and functions and contributes to the development of cardiovascular diseases and renal dysfunctions. Ceramide triggers the generation of reactive oxygen species (ROS) and increases oxidative stress in many mammalian cells and animal models. On the other hand, inhibition of ROS-generating enzymes or treatment of antioxidants impairs sphingomyelinase activation and ceramide production. As a mechanism, ceramide-enriched signaling platforms, special cell membrane rafts (MR) (formerly lipid rafts), provide an important microenvironment to mediate the cross talk of ceramide and redox signaling to exert a corresponding regulatory role on cell and organ functions. In this regard, activation of acid sphingomyelinase and generation of ceramide mediate the formation of ceramide-enriched membrane platforms, where transmembrane signals are transmitted or amplified through recruitment, clustering, assembling, or integration of various signaling molecules. A typical such signaling platform is MR redox signaling platform that is centered on ceramide production and aggregation leading to recruitment and assembling of NADPH oxidase to form an active complex in the cell plasma membrane. This redox signaling platform not only conducts redox signaling or regulation but also facilitates a feedforward amplification of both ceramide and redox signaling. In addition to this membrane MR redox signaling platform, the cross talk between ceramide and redox signaling may occur in other cell compartments. This book chapter focuses on the molecular mechanisms, spatial-temporal regulations, and implications of this cross talk between ceramide and redox signaling, which may provide novel insights into the understanding of both ceramide and redox signaling pathways.
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Affiliation(s)
- Pin-Lan Li
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298, USA.
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Monostori P, Kocsis GF, Ökrös Z, Bencsik P, Czétényi O, Kiss Z, Gellén B, Bereczki C, Ocsovszki I, Pipis J, Pálóczi J, Sárközy M, Török S, Varga IS, Kiss I, Fodor E, Csont T, Ferdinandy P, Túri S. Different administration schedules of darbepoetin alfa affect oxidized and reduced glutathione levels to a similar extent in 5/6 nephrectomized rats. Clin Exp Nephrol 2012; 17:569-74. [PMID: 23224027 DOI: 10.1007/s10157-012-0749-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 11/21/2012] [Indexed: 11/25/2022]
Abstract
BACKGROUND The development of erythropoiesis-stimulating agents (ESAs) with extended serum half-lives has allowed marked prolongation of the administration intervals. The level of oxidative stress is increased in chronic kidney disease, and is reportedly decreased after long-term ESA treatment. However, the effect of different dosing regimens of ESAs on oxidative stress has not been elucidated. METHODS Five-sixths nephrectomized (NX) rats received either 0.4 μg/kg darbepoetin alfa (DA) weekly or 0.8 μg/kg DA fortnightly between weeks 4 and 10. NX animals receiving saline and a sham-operated (SHAM) group served as controls. The levels of oxidized and reduced glutathione (GSSG, GSH) were followed from blood samples drawn fortnightly. RESULTS During the follow-up, the ratios GSSG/GSH showed similar trends in both DA groups, levels being significantly lower than those in the SHAM group at weeks 8 and 10. GSSG levels were lower than the baseline throughout the study in all groups except for NX controls. The GSH levels were increased in all three NX groups (weeks 6-10) compared with both the baseline and the SHAM group CONCLUSION Our results suggest that the extent of oxidative stress is similar in response to different dosing regimens of DA in 5/6 NX rats when comparable hemoglobin levels are maintained. These findings remain to be confirmed in chronic kidney disease patients.
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Affiliation(s)
- Péter Monostori
- Department of Pediatrics, Albert Szent-Györgyi Clinical Center, University of Szeged, Korányi fasor 14-15, Szeged, 6720, Hungary.
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Soetikno V, Sari FR, Lakshmanan AP, Arumugam S, Harima M, Suzuki K, Kawachi H, Watanabe K. Curcumin alleviates oxidative stress, inflammation, and renal fibrosis in remnant kidney through the Nrf2-keap1 pathway. Mol Nutr Food Res 2012; 57:1649-59. [PMID: 23174956 DOI: 10.1002/mnfr.201200540] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 09/18/2012] [Accepted: 09/19/2012] [Indexed: 12/20/2022]
Abstract
SCOPE We hypothesized that curcumin, by increasing the expression of nuclear factor-erythroid-2-related factor 2 (Nrf2), could reduce oxidative stress, inflammation, and renal fibrosis in remnant kidney. METHODS AND RESULTS Sprague-Dawley rats were subjected to 5/6 nephrectomy and randomly assigned to untreated (Nx), curcumin-treated (75 mg/kg/day, orally), and telmisartan-treated groups (10 mg/kg/day, orally; as positive control). Sham-operated rats also served as controls. Five/sixth nephrectomy caused renal dysfunction, as evidenced by elevated proteinuria, blood urea nitrogen, and plasma creatinine, and decreased creatinine clearance that were ameliorated by curcumin or telmisartan treatment. The Nx rats demonstrated reduced Nrf2 protein expression, whereas the Kelch-like ECH-associated protein 1 was upregulated and heme oxygenase-1 level was significantly diminished. Consequently, Nx animals had significantly higher kidney malondialdehyde concentration and lower glutathione peroxidase activity, which was associated with the upregulation of nicotinamide adenine dinucleotide phosphatase oxidase subunit (p67(phox) and p22(phox) ), NF-kappaB p65, TNF-α, TGF-β1, cyclooxygenase-2, and fibronectin accumulation in remnant kidney. Interestingly, all of these changes were ameliorated by curcumin or telmisartan. CONCLUSION These findings demonstrate that, by modulating Nrf2-Keap1 pathway, the curcumin effectively attenuates oxidative stress, inflammation, and renal fibrosis, which suggest that curcumin hold promising potential for safe treatment of chronic kidney disease.
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Affiliation(s)
- Vivian Soetikno
- Department of Clinical Pharmacology, Faculty of Pharmaceutical Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata City, Japan
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Kidokoro K, Satoh M, Nagasu H, Sakuta T, Kuwabara A, Yorimitsu D, Nishi Y, Tomita N, Sasaki T, Kashihara N. Tacrolimus induces glomerular injury via endothelial dysfunction caused by reactive oxygen species and inflammatory change. Kidney Blood Press Res 2012; 35:549-57. [PMID: 22890154 DOI: 10.1159/000339494] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 05/11/2012] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND/AIMS The immunosuppressive drug tacrolimus (FK506) is used clinically to reduce the rejection rate in patients with kidney transplantation; however, the resultant nephrotoxicity remains a serious problem. In the present study we attempted to elucidate the mechanisms of glomerular injury induced by FK506 and the renoprotective effects of the angiotensin II receptor blocker telmisartan. METHODS Seven-week-old male Wistar rats were divided into three groups: vehicle group, FK506 group, and FK506 + telmisartan group. After 8 weeks, we assessed kidney function and renal morphological changes including oxidative stress. We also assessed the effect of FK506 in human glomerular endothelial cells (hGECs) with regard to reactive oxygen species (ROS). RESULTS FK506 induced ROS production via activation of NAD(P)H oxidase in the glomeruli. Expression of ICAM mRNA was increased in glomeruli from the FK506 group. These effects resulted in macrophage infiltration into the glomeruli. FK506 directly promoted NAD(P)H oxidase activity and accelerated production of ROS in hGECs. Conversely, cotreatment with telmisartan inhibited both NAD(P)H oxidase activity and production of ROS. CONCLUSION These findings suggest that glomerular injury resulting from FK506 is caused by oxidative stress mediated by activation of NAD(P)H oxidase and that telmisartan exerts a renoprotective effect via antioxidative activity.
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Affiliation(s)
- Kengo Kidokoro
- Department of Nephrology and Hypertension, Kawasaki Medical School Kurashiki, Okayama, Japan
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Structural characteristics of renal glomerular system in ISIAH rats under conditions of chronic stress and preventive hypotensive drug therapy. Bull Exp Biol Med 2012; 152:249-52. [PMID: 22808472 DOI: 10.1007/s10517-011-1500-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
The effects of chronic stress on the structure and function of the renal glomerular system were studied in hypertensive ISIAH rats treated with hypotensive drugs during the early ontogeny. The morphometric parameters of the renal glomerular system, characteristic of each of the experimental animal groups treated by enalapril, losartan, or terazosin in early age virtually did not change under conditions of stress exposure. These results indicate a persistent delayed nephroprotective effect of these drugs.
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Chuang YC, Wu MS, Su YK, Fang KM. Effects of olmesartan on arterial stiffness in rats with chronic renal failure. Cardiovasc Diabetol 2012; 11:66. [PMID: 22694778 PMCID: PMC3472279 DOI: 10.1186/1475-2840-11-66] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 06/07/2012] [Indexed: 01/13/2023] Open
Abstract
Background It has been suggested that the antioxidant properties of olmesartan (OLM), an angiotensin II type 1 receptor (AT1R) blocker, contribute to renal protection rather than blood pressure lowering effects despite the fact that causal relationships between hypertension and renal artery disease exist. This study aimed to examine the hypothesis whether the antioxidative activities of OLM were correlated to arterial stiffness, reactive oxygen species and advanced glycation end products (AGEs) formation in rats with chronic renal failure (CRF). Methods CRF rats were induced by 5/6 nephrectomy and randomly assigned to an OLM (10 mg/day) group or a control group. Hemodynamic states, oxidative stress, renal function and AGEs were measured after 8 weeks of OLM treatment. Results All the hemodynamic derangements associated with renal and cardiovascular dysfunctions were abrogated in CRF rats receiving OLM. Decreased cardiac output was normalized compared to control (p <0.05). Mean aortic pressure, total peripheral resistance and left ventricular weight/body weight ratio were reduced by 21.6% (p <0.05), 28.2% (p <0.05) and 27.2% ((p <0.05). OLM also showed beneficial effects on the oscillatory components of the ventricular after-load, including 39% reduction in aortic characteristic impedance (p < 0.05), 75.3% increase in aortic compliance (p <0.05) and 50.3% increase in wave transit time (p < 0.05). These results implied that OLM attenuated the increased systolic load of the left ventricle and prevented cardiac hypertrophy in CRF rats. Improved renal function was also reflected by increases in the clearances of BUN (28.7%) and serum creatinine (SCr, 38.8%). In addition to these functional improvements, OLM specifically reduced the levels of malondialdehyde (MDA) equivalents in aorta and serum by 14.3% and 25.1%, as well as the amount of AGEs in the aortic wall by 32% (p < 0.05) of CRF rats. Conclusion OLM treatment could ameliorate arterial stiffness in CRF rats with concomitant inhibition of MDA and AGEs levels through the reduction of oxidative stress in aortic wall.
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Affiliation(s)
- Yao-Chen Chuang
- Institute of Physiology, College of Medicine, National Taiwan University, Taipei City, Taiwan.
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Satoh M. Endothelial dysfunction as an underlying pathophysiological condition of chronic kidney disease. Clin Exp Nephrol 2012; 16:518-21. [PMID: 22669535 DOI: 10.1007/s10157-012-0646-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 05/08/2012] [Indexed: 12/15/2022]
Abstract
Renal dysfunction and cardiovascular disorders affect each other adversely and worsen existing pathophysiological conditions. These disorders are extremely diverse in terms of pathology. Vascular disorders, in particular vascular endothelial dysfunction, are common risk factors for each other. Early endothelial dysfunction reduces vascular relaxation and causes inflammatory cell infiltration and slight inflammation in blood vessels. Endothelial dysfunction in the kidneys manifests as albuminuria. Proactive treatment is required in the early phase of endothelial dysfunction to prevent cardiovascular disease in chronic kidney disease patients.
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Affiliation(s)
- Minoru Satoh
- Department of Nephrology and Hypertension, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192, Japan.
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Fujita H, Fujishima H, Morii T, Sakamoto T, Komatsu K, Hosoba M, Narita T, Takahashi K, Takahashi T, Yamada Y. Modulation of renal superoxide dismutase by telmisartan therapy in C57BL/6-Ins2(Akita) diabetic mice. Hypertens Res 2011; 35:213-20. [PMID: 22072110 PMCID: PMC3273720 DOI: 10.1038/hr.2011.176] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Renal superoxide excess, which is induced by an imbalance of the superoxide-producing enzyme NAD(P)H oxidase and the superoxide-scavenging enzyme superoxide dismutase (SOD) under hyperglycemia, increases oxidative stress and contributes to the development of diabetic nephropathy. In this study, we treated non-obese and hypoinsulinemic C57BL/6-Ins2Akita (C57BL/6-Akita) diabetic mice with telmisartan (5 mg kg−1 per day), an angiotensin II type 1 receptor blocker, or amlodipine (5 mg kg−1 per day), a calcium channel blocker, for 4 weeks and compared the effects of these two anti-hypertensive drugs on renal NAD(P)H oxidase, SOD and transcription factor Nrf2 (NF-E2-related factor 2), which is known to upregulate several antioxidant enzymes including SOD. Vehicle-treated C57BL/6-Akita mice exhibited higher renal NAD(P)H oxidase and lower renal SOD activity with increased levels of renal superoxide than the C57BL/6-wild-type non-diabetic mice. Interestingly, telmisartan treatment not only reduced NAD(P)H oxidase activity but also enhanced SOD activity in C57BL/6-Akita mouse kidneys, leading to a reduction of renal superoxide levels. Furthermore, telmisartan-treated C57BL/6-Akita mice increased the renal protein expression of SOD and Nrf2. In parallel with the reduction of renal superoxide levels, a reduction of urinary albumin levels and a normalization of elevated glomerular filtration rate were observed in telmisartan-treated C57BL/6-Akita mice. In contrast, treatment with amlodipine failed to modulate renal NAD(P)H oxidase, SOD and Nrf2. Finally, treatment of C57BL/6-Akita mice with apocynin, an NAD(P)H oxidase inhibitor, also increased the renal protein expression of SOD and Nrf2. Collectively, our data suggest that NAD(P)H oxidase negatively regulates renal SOD, possibly by downregulation of Nrf2, and that telmisartan could upregulate renal SOD by the suppression of NAD(P)H oxidase and subsequent upregulation of Nrf2, leading to the amelioration of renal oxidative stress and diabetic renal changes.
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Affiliation(s)
- Hiroki Fujita
- Division of Endocrinology, Metabolism and Geriatric Medicine, Akita University Graduate School of Medicine, Akita, Japan.
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Nagasu H, Satoh M, Fujimoto S, Tomita N, Sasaki T, Kashihara N. Azelnidipine attenuates glomerular damage in Dahl salt-sensitive rats by suppressing sympathetic nerve activity. Hypertens Res 2011; 35:348-55. [PMID: 22072106 DOI: 10.1038/hr.2011.184] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Dihydropyridine-type calcium channel blockers (CCBs) exert potent antihypertensive effects. The CCB azelnidipine decreases heart rate by suppressing sympathetic nerve activity, which affects afferent and efferent arterioles in the glomeruli. We examined whether azelnidipine can improve progressive glomerular injury in comparison with amlodipine by suppressing renal sympathetic nerve activity in Dahl salt-sensitive rats. Glomerular circulation in Dahl salt-sensitive rats was monitored with a charge-coupled device camera before and after administration of amlodipine (0.5 mg kg(-1), bolus injection) or azelnidipine (0.1 mg kg(-1), bolus injection). Systemic sympathetic nerve activity was also compared by analysis of heart rate variability with a telemetry blood pressure monitoring system after crossover administration of amlodipine (1.0 mg kg(-1) per day) and azelnidipine (3.0 mg kg(-1) per day) for 1 week. To investigate renoprotective effects, rats were treated with amlodipine (1.0 mg kg(-1) per day) or azelnidipine (3.0 mg kg(-1) per day) for 3 weeks with or without renal denervation. The efferent arteriole contracted in response to acute amlodipine but not azelnidipine treatment. The low frequency/high frequency ratio, an index of parasympathetic nerve activity, decreased in response to azelnidipine but not amlodipine treatment. In response to chronic treatment, proteinuria and glomerular injury improved to a greater extent with azelnidipine compared with amlodipine. The renoprotective effects of azelnidipine were diminished by renal denervation. Azelnidipine decreased glomerular damage in Dahl salt-sensitive rats to a greater extent than amlodipine. Azelnidipine appeared to decrease intraglomerular pressure by suppressing sympathetic nerve activity.
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Affiliation(s)
- Hajime Nagasu
- Department of Nephrology and Hypertension, Kawasaki Medical School, Kurashiki, Okayama, Japan
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Jin S, Zhou F, Katirai F, Li PL. Lipid raft redox signaling: molecular mechanisms in health and disease. Antioxid Redox Signal 2011; 15:1043-83. [PMID: 21294649 PMCID: PMC3135227 DOI: 10.1089/ars.2010.3619] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Lipid rafts, the sphingolipid and cholesterol-enriched membrane microdomains, are able to form different membrane macrodomains or platforms upon stimulations, including redox signaling platforms, which serve as a critical signaling mechanism to mediate or regulate cellular activities or functions. In particular, this raft platform formation provides an important driving force for the assembling of NADPH oxidase subunits and the recruitment of other related receptors, effectors, and regulatory components, resulting, in turn, in the activation of NADPH oxidase and downstream redox regulation of cell functions. This comprehensive review attempts to summarize all basic and advanced information about the formation, regulation, and functions of lipid raft redox signaling platforms as well as their physiological and pathophysiological relevance. Several molecular mechanisms involving the formation of lipid raft redox signaling platforms and the related therapeutic strategies targeting them are discussed. It is hoped that all information and thoughts included in this review could provide more comprehensive insights into the understanding of lipid raft redox signaling, in particular, of their molecular mechanisms, spatial-temporal regulations, and physiological, pathophysiological relevances to human health and diseases.
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Affiliation(s)
- Si Jin
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
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Nagasu H, Satoh M, Yorimitsu D, Tomita N, Sasaki T, Kashihara N. Comparison of Combination Therapy of Olmesartan plus Azelnidipine or Hydrochlorothiazide on Renal and Vascular Damage in SHR/NDmcr-cp Rats. ACTA ACUST UNITED AC 2011; 34:87-96. [DOI: 10.1159/000323535] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 12/08/2010] [Indexed: 01/24/2023]
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Miyoshi T, Doi M, Hirohata S, Kamikawa S, Usui S, Ogawa H, Sakane K, Izumi R, Ninomiya Y, Kusachi S. Olmesartan reduces arterial stiffness and serum adipocyte fatty acid-binding protein in hypertensive patients. Heart Vessels 2010; 26:408-13. [PMID: 21063874 DOI: 10.1007/s00380-010-0060-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Accepted: 04/30/2010] [Indexed: 01/22/2023]
Abstract
Adipocyte fatty acid binding protein (A-FABP) has been reported to be involved in insulin resistance, lipid metabolism, and atherosclerosis; however, little is known about the effect of medication on the change in circulating A-FABP in human subjects. We evaluated the effects of angiotensin II type 1 receptor blocker (ARB) on arterial stiffness and its association with serum A-FABP in patients with hypertension. Thirty patients newly diagnosed with essential hypertension were treated with olmesartan (20 mg/day), an ARB, for 6 months. Serum levels of A-FABP and high-sensitivity C-reactive protein (hsCRP) were examined and the cardio-ankle vascular index (CAVI), which is a marker of arterial stiffness, was also determined. Serum A-FABP at baseline was significantly correlated with the body mass index (r = 0.45, P = 0.01), homeostasis model assessment as a marker of insulin resistance (r = 0.53, P < 0.01), and systolic blood pressure (r = 0.37, P = 0.047), and tended to be correlated with low-density lipoprotein cholesterol, triglyceride, and CAVI. Olmesartan treatment resulted in a significant decrease in CAVI, serum A-FABP levels, and hsCRP, besides a significant reduction of blood pressure. Multiple regression analysis revealed that the change in CAVI was independently correlated with the change in serum A-FABP. Olmesartan ameliorated arterial stiffness in patients with hypertension, which may be involved in the reduction of serum A-FABP.
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Affiliation(s)
- Toru Miyoshi
- Department of Molecular Biology and Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8558, Japan.
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Kuwabara A, Satoh M, Tomita N, Sasaki T, Kashihara N. Deterioration of glomerular endothelial surface layer induced by oxidative stress is implicated in altered permeability of macromolecules in Zucker fatty rats. Diabetologia 2010; 53:2056-65. [PMID: 20526760 PMCID: PMC2910881 DOI: 10.1007/s00125-010-1810-0] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Accepted: 05/06/2010] [Indexed: 02/07/2023]
Abstract
AIMS/HYPOTHESIS The glomerular endothelial layer is coated by the endothelial surface layer (ESL), which is suggested to play a role in regulation of the permselectivity of macromolecules. Production of heparanase, a degrading enzyme of the ESL, is induced by reactive oxygen species (ROS). We hypothesised that oxidative stress could cause deterioration of the glomerular ESL by induction of heparanase, resulting in increased glomerular permeability. METHODS Male Zucker fatty (ZF) rats with albuminuria and Zucker lean (ZL) rats were used in this study. Some of the ZF rats were treated with the angiotensin II receptor blocker, irbesartan. We determined the amount of ESL by wheat germ agglutinin staining and heparan sulphate proteoglycan production by western blot analysis. Glomerular hyperfiltration of macromolecules was visualised using in vivo microscopy. We used 2',7'-dichlorofluorescein diacetate-derived chemiluminescence staining to assess ROS production, and heparanase production and expression were determined by western blot analysis and quantitative real-time polymerase chain reaction respectively. RESULTS By 18 weeks of age, ZF rats had developed albuminuria. The glomerular endothelial cell glycocalyx was significantly decreased in ZF compared with ZL rats. Glomerular filtration and the permeability of macromolecules were increased in ZF, but not in ZL rats. Glomerular ROS and heparanase production were significantly increased in ZF compared with ZL rats. These changes in ZF rats were reversed by irbesartan treatment. CONCLUSIONS/INTERPRETATION Increased oxidative stress induces glomerular ESL deterioration in part through increased heparanase levels, resulting in exacerbation of glomerular permselectivity and development of albuminuria.
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Affiliation(s)
- A. Kuwabara
- Division of Nephrology and Hypertension, Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192 Japan
| | - M. Satoh
- Division of Nephrology and Hypertension, Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192 Japan
| | - N. Tomita
- Division of Nephrology and Hypertension, Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192 Japan
| | - T. Sasaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192 Japan
| | - N. Kashihara
- Division of Nephrology and Hypertension, Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192 Japan
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Satoh M, Kobayashi S, Kuwabara A, Tomita N, Sasaki T, Kashihara N. In vivo visualization of glomerular microcirculation and hyperfiltration in streptozotocin-induced diabetic rats. Microcirculation 2010; 17:103-12. [PMID: 20163537 DOI: 10.1111/j.1549-8719.2009.00010.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Knowledge of glomerular structural and hemodynamic changes in vivo is still limited under diabetic conditions. In this study, we examined the alterations in glomerular structure and permeability of macromolecules and the effects of telmisartan using a confocal laser microscope. METHODS Diabetes was induced by injecting streptozotocin. After 4 and 8 weeks, the filtration and permeability of differently sized compounds across the glomerular capillaries were visualized using a confocal laser microscope by injecting 500-kilodalton and 40-kilodalton dextran. At 7 weeks, some diabetic rats were treated with telmisartan for 1 week. The permeation of the 40-kilodalton dextran across the glomerular capillaries into Bowman's space was quantified. Glomerular volume, diameters of the afferent and efferent arterioles, and glomerular permeability were compared. RESULTS Glomerular volume was significantly increased in the diabetic rats, and there was heterogeneity in the glomerular volumes. The diameter ratio of the afferent to efferent arterioles significantly increased, and there was increased glomerular permeability in the diabetic rats compared with the control rats. Telmisartan treatment reduced glomerular permeability without affecting glomerular volume. CONCLUSIONS These data showed that glomerular hyperfiltration started from the early phase of diabetes, accompanied by dilatation of afferent arterioles and glomerular hypertrophy.
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Affiliation(s)
- Minoru Satoh
- Division of Nephrology, Department of Internal Medicine, Kawasaki Medical School, Kurashiki, Japan.
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Nagasu H, Satoh M, Kuwabara A, Yorimitsu D, Sakuta T, Tomita N, Kashihara N. Renal denervation reduces glomerular injury by suppressing NAD(P)H oxidase activity in Dahl salt-sensitive rats. Nephrol Dial Transplant 2010; 25:2889-98. [DOI: 10.1093/ndt/gfq139] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Sakuta T, Morita Y, Satoh M, Fox DA, Kashihara N. Involvement of the renin-angiotensin system in the development of vascular damage in a rat model of arthritis: Effect of angiotensin receptor blockers. ACTA ACUST UNITED AC 2010; 62:1319-28. [DOI: 10.1002/art.27384] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Satoh M, Haruna Y, Fujimoto S, Sasaki T, Kashihara N. Telmisartan improves endothelial dysfunction and renal autoregulation in Dahl salt-sensitive rats. Hypertens Res 2010; 33:135-42. [PMID: 19927153 DOI: 10.1038/hr.2009.190] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Hypertensive vascular disorders are characterized by endothelial dysfunction. Loss of renal autoregulation causes glomerular hypertension. However, the relationship between the autoregulatory response and glomerular damage has not been well examined. We examined the contributions of uncoupled endothelial nitric oxide synthase (eNOS) in hypertensive renal disease, and the relationship between the degree of autoregulation impairment and glomerular injury. We also investigated the effects of telmisartan on eNOS coupling and renal autoregulation. Male Dahl salt-sensitive hypertensive (DS) rats (14-week old) fed an 8% salt diet were used to examine endothelial dysfunction and impaired renal autoregulation caused by glomerular hypertension. Some DS rats were treated with telmisartan (3.0 mg kg(-1) day(-1)), an angiotensin receptor blocker, for 2 weeks. Increased superoxide production and decreased nitric oxide production, as detected by fluorescent indicator perfusion methods, were observed in the glomeruli and arterioles of hypertensive DS rats. Telmisartan improved the imbalance of superoxide and nitric oxide in the glomeruli and arterioles. Decreased serum tetrahydrobiopterin levels and coupled eNOS seen in the DS rat kidney were improved with telmisartan treatment. The endothelial relaxation reaction was impaired in DS rat aortic arteries. Autoregulatory capacity in response to step changes in perfusion pressure was also impaired in DS rat kidney. Treatment with telmisartan improved these abnormalities. Endothelial dysfunction in the glomeruli and impaired renal autoregulation, which may cause glomerular sclerosis, were observed in DS rat kidney. Telmisartan treatment improves these dysfunctions in hypertensive renal disease.
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Affiliation(s)
- Minoru Satoh
- Division of Nephrology, Department of Internal Medicine, Kawasaki Medical School, Kurashiki, Okayama, Japan.
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Okamura DM, Himmelfarb J. Tipping the redox balance of oxidative stress in fibrogenic pathways in chronic kidney disease. Pediatr Nephrol 2009; 24:2309-19. [PMID: 19421784 DOI: 10.1007/s00467-009-1199-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 04/01/2009] [Accepted: 04/02/2009] [Indexed: 12/21/2022]
Abstract
Patients with moderate to advanced chronic kidney disease or end-stage renal disease have a greatly increased cardiovascular risk that cannot be explained entirely by traditional cardiovascular risk factors. An increase in oxidative stress and inflammation have been proposed as nontraditional cardiovascular risk factors in this patient population. Oxidative stress reflects the redox balance between oxidant generation and antioxidant mechanisms. The generation of reactive oxygen species is not simply a random process that oxidizes nearby macromolecules, but, in many instances, the oxidants target particular amino acid residues or lipid moieties. Oxidant mechanisms are now recognized to be intimately involved in cell signaling and to be vital components of the immune response. This is equally true for antioxidant mechanisms as well. In the progression of chronic kidney disease, the redox balance is not in equilibrium and is tipped toward oxidation, resulting in the dysregulation of cellular process and subsequent tissue injury. In this review we discuss the major oxidant and antioxidant pathways and the biomarkers to assess redox status. We also review the data linking the pathogenesis of oxidative stress, inflammation, and the progressive loss of kidney function in chronic kidney disease.
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Affiliation(s)
- Daryl M Okamura
- Seattle Children's Research Institute, Department of Pediatrics, University of Washington, Seattle, WA, USA.
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Albayrak S, Ordu S, Ozhan H, Yazici M, Aydin M, Alemdar R, Kaya A. Effect of olmesartan medoxomil on cystatin C level, left ventricular hypertrophy and diastolic function. Blood Press 2009; 18:187-91. [DOI: 10.1080/08037050903047236] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Ozeki M, Nagasu H, Satoh M, Namikoshi T, Haruna Y, Tomita N, Sasaki T, Kashihara N. Reactive oxygen species mediate compensatory glomerular hypertrophy in rat uninephrectomized kidney. J Physiol Sci 2009; 59:397-404. [PMID: 19593678 PMCID: PMC10717616 DOI: 10.1007/s12576-009-0048-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Accepted: 06/09/2009] [Indexed: 11/24/2022]
Abstract
Hyperfiltration in glomeruli is the most common pathway to progressive renal dysfunction. Moreover, reduction of renal mass by unilateral nephrectomy results in an immediate increase in glomerular flow to the remnant kidney, followed by compensatory glomerular hypertrophy. Reactive oxygen species (ROS) are involved in renal hypertrophic responses; however, the role of ROS in compensatory glomerular hypertrophy remains unclear. Therefore, this role was investigated in the present study. Wistar rats were randomly placed into two groups: uninephrectomized rats (Nx) and uninephrectomized rats treated with tempol (Nx + TP). The glomerular volume increased in the Nx 1 week after surgery, but was significantly suppressed in the Nx + TP. Levels of phospho-Akt and phospho-ribosomal protein S6, which are critical for cell growth and hypertrophy, were markedly increased in the glomeruli of the Nx, while tempol treatment almost abolished the activation of these proteins. These results suggest that ROS have important roles in compensatory hypertrophy in glomeruli.
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Affiliation(s)
- Masahito Ozeki
- Division of Nephrology, Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192 Japan
| | - Hajime Nagasu
- Division of Nephrology, Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192 Japan
| | - Minoru Satoh
- Division of Nephrology, Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192 Japan
| | - Tamehachi Namikoshi
- Division of Nephrology, Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192 Japan
| | - Yoshisuke Haruna
- Division of Nephrology, Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192 Japan
| | - Naruya Tomita
- Division of Nephrology, Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192 Japan
| | - Tamaki Sasaki
- Division of Nephrology, Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192 Japan
| | - Naoki Kashihara
- Division of Nephrology, Department of Internal Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192 Japan
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Namikoshi T, Tomita N, Satoh M, Sakuta T, Kuwabara A, Kobayashi S, Higuchi Y, Nishijima F, Kashihara N. Oral adsorbent AST-120 ameliorates endothelial dysfunction independent of renal function in rats with subtotal nephrectomy. Hypertens Res 2009; 32:194-200. [PMID: 19262482 DOI: 10.1038/hr.2008.29] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
It is important to consider a strategy to halt the development of cardiovascular disease (CVD) in patients with chronic kidney disease (CKD). Oral adsorbent AST-120 retards deterioration in renal function, reducing indoxyl sulfate (IS) accumulation. The aim of this study was to determine whether AST-120 improves endothelial dysfunction by reducing oxidative/nitrative stress in a rat-CKD model. Subtotally nephrectomized (Nx) rats aged 17 weeks were divided into two groups: control rats and rats orally treated with AST-120. Two weeks after initiation of AST-120, serum and urinary IS levels, renal histological scores and endothelium-dependent vascular responses (EDVRs) in the aorta were investigated. EDVR in 5-h incubation with 250 microg ml(-1) IS was also examined in normal rat aortas. Nitrotyrosine content, mRNA expression of p47phox, a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase component, and expression and phosphorylation (serine-1177) of endothelial nitric oxide synthase (eNOS) in the aorta were examined in untreated and treated Nx rats. At the end of treatment, renal function and histological scores were not different in the two groups. AST-120 prevented the elevation of serum IS level in Nx rats, reducing urinary IS excretion, and ameliorated decreased EDVR in Nx rats. Incubation with IS tended to reduce EDVR in normal aortas, albeit insignificantly. AST-120 also suppressed nitrotyrosine accumulation and inhibited p47phox expression in Nx rats. The eNOS expression and phosphorylation were similar in the two groups. In conclusion, AST-120 ameliorated endothelial dysfunction and alleviated oxidative/nitrative stress in the aorta through reduced accumulation of IS, independent of renal function, in a rat CKD model.
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Affiliation(s)
- Tamehachi Namikoshi
- Division of Nephrology, Department of Internal Medicine, Kawasaki Medical School, Kurashiki, Japan
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Satoh M, Fujimoto S, Arakawa S, Yada T, Namikoshi T, Haruna Y, Horike H, Sasaki T, Kashihara N. Angiotensin II type 1 receptor blocker ameliorates uncoupled endothelial nitric oxide synthase in rats with experimental diabetic nephropathy. Nephrol Dial Transplant 2008; 23:3806-13. [PMID: 18596126 PMCID: PMC2639062 DOI: 10.1093/ndt/gfn357] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Accepted: 06/02/2008] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Recent studies showed that angiotensin II type 1 receptor blocker (ARB) slows progression of chronic renal disease in patients with type 2 diabetes, regardless of changes in blood pressure. We showed that the imbalance of nitric oxide (NO) and reactive oxygen species (ROS) due to endothelial NO synthase (eNOS) uncoupling contributed to renal dysfunction in the diabetic nephropathy. The aim of this study was to determine the effects of ARB on uncoupled eNOS in rat diabetic nephropathy. METHODS Diabetes was induced in Sprague-Dawley rats with streptozotocin (65 mg/ kg body weight). After 6 weeks, rats were divided into saline (DM; n = 11) and ARB, losartan groups (DM+Los; n = 11). After 2-week treatment, glomerular ROS production was assessed by 2',7'-dichlorofluorescin diacetate (DCFH-DA)-derived chemiluminescence. Renal NO and ROS production were imaged by confocal laser microscopy after renal perfusion with DCFH-DA and diaminorhodamine-4M acetoxymethyl ester with L-arginine. The dimeric form of eNOS was measured by low-temperature sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Serum tetrahydrobiopterin (BH4) concentrations were determined by high-performance liquid chromatography. Protein and mRNA expression of GTP cyclohydrolase 1 (GTPCH1), key enzyme of BH4 synthesis, were examined. RESULTS Losartan attenuated glomerular ROS production in DM. Accelerated ROS production and diminished bioavailable NO caused by NOS uncoupling were noted in DM glomeruli. Losartan reversed the decreased GTPCH1 and decreased dimeric form of eNOS and glomerular NO production by increased BH4 bioavailability. CONCLUSIONS ARB improved the NOS uncoupling in diabetic nephropathy by increasing BH4 bioavailability.
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Affiliation(s)
- Minoru Satoh
- Division of Nephrology, Department of Internal Medicine, Kawasaki Medical School, Kurashiki, Okayama 701-0192, Japan.
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Koga Y, Hirooka Y, Araki S, Nozoe M, Kishi T, Sunagawa K. High Salt Intake Enhances Blood Pressure Increase during Development of Hypertension via Oxidative Stress in Rostral Ventrolateral Medulla of Spontaneously Hypertensive Rats. Hypertens Res 2008; 31:2075-83. [DOI: 10.1291/hypres.31.2075] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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