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Chevalier RL. Why is chronic kidney disease progressive? Evolutionary adaptations and maladaptations. Am J Physiol Renal Physiol 2023; 325:F595-F617. [PMID: 37675460 DOI: 10.1152/ajprenal.00134.2023] [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: 05/19/2023] [Revised: 08/08/2023] [Accepted: 08/27/2023] [Indexed: 09/08/2023] Open
Abstract
Despite significant advances in renal physiology, the global prevalence of chronic kidney disease (CKD) continues to increase. The emergence of multicellular organisms gave rise to increasing complexity of life resulting in trade-offs reflecting ancestral adaptations to changing environments. Three evolutionary traits shape CKD over the lifespan: 1) variation in nephron number at birth, 2) progressive nephron loss with aging, and 3) adaptive kidney growth in response to decreased nephron number. Although providing plasticity in adaptation to changing environments, the cell cycle must function within constraints dictated by available energy. Prioritized allocation of energy available through the placenta can restrict fetal nephrogenesis, a risk factor for CKD. Moreover, nephron loss with aging is a consequence of cell senescence, a pathway accelerated by adaptive nephron hypertrophy that maintains metabolic homeostasis at the expense of increased vulnerability to stressors. Driven by reproductive fitness, natural selection operates in early life but diminishes thereafter, leading to an exponential increase in CKD with aging, a product of antagonistic pleiotropy. A deeper understanding of the evolutionary constraints on the cell cycle may lead to manipulation of the balance between progenitor cell renewal and differentiation, regulation of cell senescence, and modulation of the balance between cell proliferation and hypertrophy. Application of an evolutionary perspective may enhance understanding of adaptation and maladaptation by nephrons in the progression of CKD, leading to new therapeutic advances.
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Affiliation(s)
- Robert L Chevalier
- Department of Pediatrics, The University of Virginia, Charlottesville, Virginia, United States
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2
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Kung CW, Chou YH. Acute kidney disease: an overview of the epidemiology, pathophysiology, and management. Kidney Res Clin Pract 2023; 42:686-699. [PMID: 37165615 DOI: 10.23876/j.krcp.23.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 02/20/2023] [Indexed: 05/12/2023] Open
Abstract
Acute kidney injury (AKI) increases the risk of chronic kidney disease (CKD), and AKI and CKD are seen as interconnected syndromes. Acute kidney disease (AKD) is defined as subacute damage and/or loss of kidney function occurring 7 to 90 days after AKI, during which period key interventions may be initiated to hinder the development of CKD. While AKD is usually under-recognized, it is associated with high morbidity and mortality globally. This review article aims to summarize the current knowledge concerning the epidemiology, pathophysiology, and management of AKD with the aim to develop monitoring strategies and therapeutic agents of AKD. Generally, AKD tends to occur more frequently in the elderly and those with chronic diseases, such as hypertension, diabetes mellitus, and metabolic syndrome. In addition, the severity, duration, and frequency of AKI are independent risk factors for AKD. Investigations of several mechanisms of AKD, such as renal tubular epithelium cell-cycle arrest, epigenetic change, chronic inflammation, mitochondria dysfunction, failed regeneration of tubular cells, metabolic reprogramming, and renin-angiotensin system (RAS) activation, have identified additional potential pharmacotherapy targets. Management of AKD includes prevention of repeated AKI, early and regular follow-up by a nephrologist, resumption and adjustment of essential medication, optimization of blood pressure control and nutrition management, and development of new pharmaceutical agents including RAS inhibitors. Finally, we outline a care bundle for AKD patients based on important lessons learned from studies and registries and identify the need for clinical trials of RAS inhibitors or other novel agents to impede ensuing CKD development.
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Affiliation(s)
- Chin-Wei Kung
- Department of Internal Medicine, China Medical University Hospital, China Medical University College of Medicine, Taichung, Taiwan
| | - Yu-Hsiang Chou
- Renal Division, Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei City, Taiwan
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3
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Zambom FFF, Albino AH, Tessaro HM, Foresto-Neto O, Malheiros DMAC, Saraiva Camara NO, Zatz R. Chronic environmental hypoxia attenuates innate immunity activation and renal injury in two CKD models. Am J Physiol Renal Physiol 2023; 325:F283-F298. [PMID: 37439199 DOI: 10.1152/ajprenal.00200.2022] [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: 07/19/2022] [Revised: 06/13/2023] [Accepted: 07/03/2023] [Indexed: 07/14/2023] Open
Abstract
Tissue hypoxia has been pointed out as a major pathogenic factor in chronic kidney disease (CKD). However, epidemiological and experimental evidence inconsistent with this notion has been described. We have previously reported that chronic exposure to low ambient Po2 promoted no renal injury in normal rats and in rats with 5/6 renal ablation (Nx) unexpectedly attenuated renal injury. In the present study, we investigated whether chronic exposure to low ambient Po2 would also be renoprotective in two additional models of CKD: adenine (ADE) excess and chronic nitric oxide (NO) inhibition. In both models, normobaric ambient hypoxia attenuated the development of renal injury and inflammation. In addition, renal hypoxia limited the activation of NF-κB and NOD-like receptor family pyrin domain containing 3 inflammasome cascades as well as oxidative stress and intrarenal infiltration by angiotensin II-positive cells. Renal activation of hypoxia-inducible factor (HIF)-2α, along with other adaptive mechanisms to hypoxia, may have contributed to these renoprotective effects. The present findings may contribute to unravel the pathogenesis of CKD and to the development of innovative strategies to arrest its progression.NEW & NOTEWORTHY Hypoxia is regarded as a major pathogenic factor in chronic kidney disease (CKD). In disagreement with this view, we show here that sustained exposure to low ambient Po2 lessened kidney injury and inflammation in two CKD models: adenine (ADE) excess and chronic nitric oxide (NO) inhibition. Together with our previous findings in the remnant kidney, these observations indicate that local changes elicited by hypoxia may exert renoprotection in CKD, raising the prospect of novel therapeutic strategies for this disease.
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Affiliation(s)
| | - Amanda Helen Albino
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Helena Mendonça Tessaro
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Orestes Foresto-Neto
- Laboratory of Transplantation Immunobiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | | | - Niels Olsen Saraiva Camara
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
- Laboratory of Transplantation Immunobiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Roberto Zatz
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
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Fang T, Ma C, Zhang Z, Sun L, Zheng N. Roxadustat, a HIF-PHD inhibitor with exploitable potential on diabetes-related complications. Front Pharmacol 2023; 14:1088288. [PMID: 36843948 PMCID: PMC9950780 DOI: 10.3389/fphar.2023.1088288] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 01/26/2023] [Indexed: 02/12/2023] Open
Abstract
Diabetes mellitus (DM) is a group of metabolic diseases caused by absolute or relative deficiency of insulin secretion and characterized by chronic hyperglycemia. Its complications affect almost every tissue of the body, usually leading to blindness, renal failure, amputation, etc. and in the final stage, it mostly develops into cardiac failure, which is the main reason why diabetes mellitus manifests itself as a high clinical lethality. The pathogenesis of diabetes mellitus and its complications involves various pathological processes including excessive production of mitochondrial reactive oxygen species (ROS) and metabolic imbalance. Hypoxia-inducible Factor (HIF) signaling pathway plays an important role in both of the above processes. Roxadustat is an activator of Hypoxia-inducible Factor-1α, which increases the transcriptional activity of Hypoxia-inducible Factor-1α by inhibiting hypoxia-inducible factor prolyl hydroxylase (HIF-PHD). Roxadustat showed regulatory effects on maintaining metabolic stability in the hypoxic state of the body by activating many downstream signaling pathways such as vascular endothelial growth factor (VEGF), glucose transporter protein-1 (GLUT1), lactate dehydrogenase (LDHA), etc. This review summarizes the current research findings of roxadustat on the diseases of cardiomyopathy, nephropathy, retinal damage and impaired wound healing, which also occur at different stages of diabetes and greatly contribute to the damage caused by diabetes to the organism. We attempts to uncover a more comprehensive picture of the therapeutic effects of roxadustat, and inform its expanding research about diabetic complications treatment.
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Affiliation(s)
- Tingting Fang
- Department of Pathophysiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning, China
| | - Congcong Ma
- Department of Pathophysiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning, China
| | - Zhanming Zhang
- Pharmaceutical Sciences, China Medical University-The Queen’s University of Belfast Joint College, Shenyang, Liaoning, China
| | - Luning Sun
- Department of Pathophysiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning, China
| | - Ningning Zheng
- Department of Pathophysiology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning, China,*Correspondence: Ningning Zheng,
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5
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Molecular Mechanisms of Hypertensive Nephropathy: Renoprotective Effect of Losartan through Hsp70. Cells 2021; 10:cells10113146. [PMID: 34831368 PMCID: PMC8619557 DOI: 10.3390/cells10113146] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/28/2021] [Accepted: 11/02/2021] [Indexed: 02/06/2023] Open
Abstract
Hypertensive nephrosclerosis is the second most common cause of end-stage renal disease after diabetes. For years, hypertensive kidney disease has been focused on the afferent arterioles and glomeruli damage and the involvement of the renin angiotensin system (RAS). Nonetheless, in recent years, novel evidence has demonstrated that persistent high blood pressure injures tubular cells, leading to epithelial–mesenchymal transition (EMT) and tubulointerstitial fibrosis. Injury primarily determined at the glomerular level by hypertension causes changes in post-glomerular peritubular capillaries that in turn induce endothelial damage and hypoxia. Microvasculature dysfunction, by inducing hypoxic environment, triggers inflammation, EMT with epithelial cells dedifferentiation and fibrosis. Hypertensive kidney disease also includes podocyte effacement and loss, leading to disruption of the filtration barrier. This review highlights the molecular mechanisms and histologic aspects involved in the pathophysiology of hypertensive kidney disease incorporating knowledge about EMT and tubulointerstitial fibrosis. The role of the Hsp70 chaperone on the angiotensin II–induced EMT after angiotensin II type 1 receptor (AT1R) blockage, as a possible molecular target for therapeutic strategy against hypertensive renal damage is discussed.
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Ricksten SE, Bragadottir G, Lannemyr L, Redfors B, Skytte J. Renal Hemodynamics, Function, and Oxygenation in Critically Ill Patients and after Major Surgery. KIDNEY360 2021; 2:894-904. [PMID: 35373068 PMCID: PMC8791344 DOI: 10.34067/kid.0007012020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/02/2021] [Indexed: 02/04/2023]
Abstract
This review outlines the available data from the work of our group on renal hemodynamics, function, and oxygenation in patients who are critically ill with acute renal dysfunction, such as those with postoperative AKI, those in early clinical septic shock, in patients undergoing cardiac surgery with cardiopulmonary bypass, or in patients undergoing liver transplantation. We also provide information on renal hemodynamics, function, and oxygenation in patients with chronic renal impairment due to congestive heart failure. This review will argue that, for all of these groups of patients, the common denominator is that renal oxygenation is impaired due to a lower renal oxygen delivery or a pronounced increase in renal oxygen consumption.
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7
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McWilliam SJ, Wright RD, Welsh GI, Tuffin J, Budge KL, Swan L, Wilm T, Martinas IR, Littlewood J, Oni L. The complex interplay between kidney injury and inflammation. Clin Kidney J 2021; 14:780-788. [PMID: 33777361 PMCID: PMC7986351 DOI: 10.1093/ckj/sfaa164] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 06/10/2020] [Indexed: 12/11/2022] Open
Abstract
Acute kidney injury (AKI) has gained significant attention following patient safety alerts about the increased risk of harm to patients, including increased mortality and hospitalization. Common causes of AKI include hypovolaemia, nephrotoxic medications, ischaemia and acute glomerulonephritis, although in reality it may be undetermined or multifactorial. A period of inflammation either as a contributor to the kidney injury or resulting from the injury is almost universally seen. This article was compiled following a workshop exploring the interplay between injury and inflammation. AKI is characterized by some degree of renal cell death through either apoptosis or necrosis, together with a strong inflammatory response. Studies interrogating the resolution of renal inflammation identify a whole range of molecules that are upregulated and confirm that the kidneys are able to intrinsically regenerate after an episode of AKI, provided the threshold of damage is not too high. Kidneys are unable to generate new nephrons, and dysfunctional or repeated episodes will lead to further nephron loss that is ultimately associated with the development of renal fibrosis and chronic kidney disease (CKD). The AKI to CKD transition is a complex process mainly facilitated by maladaptive repair mechanisms. Early biomarkers mapping out this process would allow a personalized approach to identifying patients with AKI who are at high risk of developing fibrosis and subsequent CKD. This review article highlights this process and explains how laboratory models of renal inflammation and injury assist with understanding the underlying disease process and allow interrogation of medications aimed at targeting the mechanistic interplay.
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Affiliation(s)
- Stephen J McWilliam
- Department of Paediatric Pharmacology, Alder Hey Children’s Hospital, Liverpool, UK
- Department of Women and Children’s Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Rachael D Wright
- Department of Women and Children’s Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Gavin I Welsh
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Jack Tuffin
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Kelly L Budge
- Department of Women and Children’s Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Laura Swan
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Thomas Wilm
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Ioana-Roxana Martinas
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - James Littlewood
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
- Department of Nephrology, Royal Liverpool University Hospital, Liverpool, UK
| | - Louise Oni
- Department of Women and Children’s Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
- Department of Paediatric Nephrology, Alder Hey Children’s NHS Foundation Trust Hospital, Liverpool, UK
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8
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Kratky V, Vanourkova Z, Sykora M, Bacova BS, Hruskova Z, Kikerlova S, Huskova Z, Kopkan L. AT 1 receptor blocker, but not an ACE inhibitor, prevents kidneys from hypoperfusion during congestive heart failure in normotensive and hypertensive rats. Sci Rep 2021; 11:4271. [PMID: 33608612 PMCID: PMC7896062 DOI: 10.1038/s41598-021-83906-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 02/08/2021] [Indexed: 12/22/2022] Open
Abstract
To provide novel insights into the pathogenesis of heart failure-induced renal dysfunction, we compared the effects of ACE inhibitor (ACEi) and AT1 receptor blocker (ARB) on systemic and kidney hemodynamics during heart failure in normotensive HanSD and hypertensive transgenic (TGR) rats. High-output heart failure was induced by creating an aorto-caval fistula (ACF). After five weeks, rats were either left untreated or treatment with ACEi or ARB was started for 15 weeks. Subsequently, echocardiographic, renal hemodynamic and biochemical measurements were assessed. Untreated ACF rats with ACF displayed significantly reduced renal blood flow (RBF) (HanSD: 8.9 ± 1.0 vs. 4.7 ± 1.6; TGR: 10.2 ± 1.9 vs. 5.9 ± 1.2 ml/min, both P < .001), ACEi had no major RBF effect, whereas ARB completely restored RBF (HanSD: 5.6 ± 1.1 vs. 9.0 ± 1.5; TGR: 7.0 ± 1.2 vs. 10.9 ± 1.9 ml/min, both P < .001). RBF reduction in untreated and ACEi-treated rats was accompanied by renal hypoxia as measured by renal lactate dehydrogenase activity, which was ameliorated with ARB treatment (HanSD: 40 ± 4 vs. 42 ± 3 vs. 29 ± 5; TGR: 88 ± 4 vs. 76 ± 4 vs. 58 ± 4 milliunits/mL, all P < .01). Unlike improvement seen in ARB-treated rats, ACE inhibition didn’t affect urinary nitrates compared to untreated ACF TGR rats (50 ± 14 vs. 22 ± 13 vs. 30 ± 13 μmol/mmol Cr, both P < .05). ARB was more effective than ACEi in reducing elevated renal oxidative stress following ACF placement. A marker of ACEi efficacy, the angiotensin I/angiotensin II ratio, was more than ten times lower in renal tissue than in plasma. Our study shows that ARB treatment, in contrast to ACEi administration, prevents renal hypoperfusion and hypoxia in ACF rats with concomitant improvement in NO bioavailability and oxidative stress reduction. The inability of ACE inhibition to improve renal hypoperfusion in ACF rats may result from incomplete intrarenal RAS suppression in the face of depleted compensatory mechanisms.
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Affiliation(s)
- Vojtech Kratky
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, 1958/9 Videnska, 14000, Prague 4, Czech Republic. .,Department of Pathophysiology, 2nd Faculty of Medicine, Charles University, Prague, Czech Republic. .,Department of Nephrology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic.
| | - Zdenka Vanourkova
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, 1958/9 Videnska, 14000, Prague 4, Czech Republic
| | - Matus Sykora
- Institute for Heart Research, Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Barbara Szeiffova Bacova
- Institute for Heart Research, Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Zdenka Hruskova
- Department of Nephrology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Sona Kikerlova
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, 1958/9 Videnska, 14000, Prague 4, Czech Republic
| | - Zuzana Huskova
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, 1958/9 Videnska, 14000, Prague 4, Czech Republic
| | - Libor Kopkan
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, 1958/9 Videnska, 14000, Prague 4, Czech Republic
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Zhao K, Pohlmann A, Feng Q, Mei Y, Yang G, Yi P, Feng Q, Chen W, Zhou L, Wu EX, Seeliger E, Niendorf T, Feng Y. Physiological system analysis of the kidney by high-temporal-resolution T 2 ∗ monitoring of an oxygenation step response. Magn Reson Med 2020; 85:334-345. [PMID: 32710578 DOI: 10.1002/mrm.28399] [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: 04/15/2020] [Revised: 05/21/2020] [Accepted: 06/08/2020] [Indexed: 11/11/2022]
Abstract
PURPOSE Examine the feasibility of characterizing the regulation of renal oxygenation using high-temporal-resolution monitoring of the T 2 ∗ response to a step-like oxygenation stimulus. METHODS For T 2 ∗ mapping, multi-echo gradient-echo imaging was used (temporal resolution = 9 seconds). A step-like renal oxygenation challenge was applied involving sequential exposure to hyperoxia (100% O2 ), hypoxia (10% O2 + 90% N2 ), and hyperoxia (100% O2 ). In vivo experiments were performed in healthy rats (N = 10) and in rats with bilateral ischemia-reperfusion injury (N = 4). To assess the step response of renal oxygenation, a second-order exponential model was used (model parameters: amplitude [A], time delay [Δt], damping constant [D], and period of the oscillation [T]) for renal cortex, outer stripe of the outer medulla, inner stripe of the outer medulla, and inner medulla. RESULTS The second-order exponential model permitted us to model the exponential T 2 ∗ recovery and the superimposed T 2 ∗ oscillation following renal oxygenation stimulus. The in vivo experiments revealed a difference in Douter medulla between healthy controls (D < 1, indicating oscillatory recovery) and ischemia-reperfusion injury (D > 1, reflecting aperiodic recovery). The increase in Douter medulla by a factor of 3.7 (outer stripe of the outer medulla) and 10.0 (inner stripe of the outer medulla) suggests that this parameter might be rather sensitive to (patho)physiological oxygenation changes. CONCLUSION This study demonstrates the feasibility of monitoring the dynamic oxygenation response of renal tissues to a step-like oxygenation challenge using high-temporal-resolution T 2 ∗ mapping. Our results suggest that the implemented system analysis approach may help to unlock questions regarding regulation of renal oxygenation, with the ultimate goal of providing imaging means for diagnostics and therapy of renal diseases.
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Affiliation(s)
- Kaixuan Zhao
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
| | - Andreas Pohlmann
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Qijian Feng
- State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yingjie Mei
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China.,Philips Healthcare, Guangzhou, China
| | - Guixiang Yang
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
| | - Peiwei Yi
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
| | - Qianjin Feng
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
| | - Wufang Chen
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
| | - Lili Zhou
- State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Ed X Wu
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, China
| | - Erdmann Seeliger
- Center for Cardiovascular Research, Institute of Physiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Yanqiu Feng
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
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Faivre A, Scholz CC, de Seigneux S. Hypoxia in chronic kidney disease: towards a paradigm shift? Nephrol Dial Transplant 2020; 36:1782-1790. [PMID: 33895835 DOI: 10.1093/ndt/gfaa091] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Indexed: 11/15/2022] Open
Abstract
Chronic kidney disease (CKD) is defined as an alteration of kidney structure and/or function lasting for >3 months [1]. CKD affects 10% of the general adult population and is responsible for large healthcare costs [2]. Since the end of the last century, the role of hypoxia in CKD progression has controversially been discussed. To date, there is evidence of the presence of hypoxia in late-stage renal disease, but we lack time-course evidence, stage correlation and also spatial co-localization with fibrotic lesions to ensure its causative role. The classical view of hypoxia in CKD progression is that it is caused by peritubular capillary alterations, renal anaemia and increased oxygen consumption regardless of the primary injury. In this classical view, hypoxia is assumed to further induce pro-fibrotic and pro-inflammatory responses, as well as oxidative stress, leading to CKD worsening as part of a vicious circle. However, recent investigations tend to question this paradigm, and both the presence of hypoxia and its role in CKD progression are still not clearly demonstrated. Hypoxia-inducible factor (HIF) is the main transcriptional regulator of the hypoxia response. Genetic HIF modulation leads to variable effects on CKD progression in different murine models. In contrast, pharmacological modulation of the HIF pathway [i.e. by HIF hydroxylase inhibitors (HIs)] appears to be generally protective against fibrosis progression experimentally. We here review the existing literature on the role of hypoxia, the HIF pathway and HIF HIs in CKD progression and summarize the evidence that supports or rejects the hypoxia hypothesis, respectively.
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Affiliation(s)
- Anna Faivre
- Department of Cell physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Carsten C Scholz
- Institute of Physiology, University of Zurich, Zurich, Switzerland.,National Centre of Competence in Research "Kidney.CH", Zurich, Switzerland
| | - Sophie de Seigneux
- Department of Cell physiology and Metabolism, University of Geneva, Geneva, Switzerland.,National Centre of Competence in Research "Kidney.CH", Zurich, Switzerland.,Department of Medicine, Service of Nephrology, Geneva University Hospitals, Geneva, Switzerland
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11
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Lourenço BN, Coleman AE, Schmiedt CW, Brown CA, Rissi DR, Stanton JB, Giguère S, Berghaus RD, Brown SA, Tarigo JL. Profibrotic gene transcription in renal tissues from cats with ischemia-induced chronic kidney disease. Am J Vet Res 2020; 81:180-189. [PMID: 31985291 DOI: 10.2460/ajvr.81.2.180] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To characterize transcription of profibrotic mediators in renal tissues of cats with ischemia-induced chronic kidney disease (CKD). SAMPLE Banked renal tissues from 6 cats with experimentally induced CKD (RI group) and 8 healthy control cats. PROCEDURES For cats of the RI group, both kidneys were harvested 6 months after ischemia was induced for 90 minutes in 1 kidney. For control cats, the right kidney was evaluated. All kidney specimens were histologically examined for fibrosis, inflammation, and tubular atrophy. Renal tissue homogenates underwent reverse transcription quantitative PCR assay evaluation to characterize gene transcription of hypoxia-inducible factor-1α (HIF-1α), matrix metalloproteinase (MMP)-2, MMP-7, MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1), transforming growth factor-β1, and vascular endothelial growth factor A. Gene transcription and histologic lesions were compared among ischemic and contralateral kidneys of the RI group and control kidneys. RESULTS Ischemic kidneys had greater transcript levels of MMP-7, MMP-9, and transforming growth factor-β1 relative to control kidneys and of MMP-2 relative to contralateral kidneys. Transcription of TIMP-1 was upregulated and that of vascular endothelial growth factor A was downregulated in ischemic and contralateral kidneys relative to control kidneys. Transcription of HIF-1α did not differ among kidney groups. For ischemic kidneys, there were strong positive correlations between transcription of HIF-1α, MMP-2, MMP-7, and TIMP-1 and severity of fibrosis. CONCLUSIONS AND CLINICAL RELEVANCE Transcription of genes involved in profibrotic pathways remained altered in both kidneys 6 months after transient renal ischemia. This suggested that a single unilateral renal insult can have lasting effects on both kidneys.
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12
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Zhou J, Zhou H, Liu C, Huang L, Lu D, Gao C. HDAC1-mediated deacetylation of LSD1 regulates vascular calcification by promoting autophagy in chronic renal failure. J Cell Mol Med 2020; 24:8636-8649. [PMID: 32596952 PMCID: PMC7412400 DOI: 10.1111/jcmm.15494] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 05/19/2020] [Accepted: 05/24/2020] [Indexed: 12/13/2022] Open
Abstract
Chronic renal failure (CRF) is commonly associated with various adverse consequences including pathological vascular calcification (VC), which represents a significant clinical concern. Existing literature has suggested the involvement of histone deacetylases (HDACs) in the progression of CRF‐induced VC. However, the underlying molecular mechanisms associated with HDACs remain largely unknown. Therefore, we established the adenine‐induced CRF rat model and in vitro VC models based on vascular smooth muscle cells (VSMCs) to examine HDAC1/lysine demethylase 1A (LSD1)/SESN2 as a novel molecular pathway in CRF‐induced VC. Our initial results demonstrated that HDAC1 reduced the formation of VC in vivo and in vitro. HDAC1 was found to deacetylate LSD1, which subsequently led to impaired transcriptional activity in CRF‐induced VC. Moreover, our results illustrated that LSD1 diminished the enrichment of H3K4me2 at the SESN2 promoter. Autophagy was identified as a vasculo‐protective element against calcification in VC. Finally, we found that the inhibitory effects of HDAC1 overexpression on VC were partially abolished via over‐expressed LSD1 in adenine‐induced CRF model rats and in high phosphate‐induced VSMCs. Taken together, these results highlight the crucial role of HDAC1 as an antagonistic factor in the progression of VC in CRF, and also revealed a novel regulatory mechanism by which HDAC1 operates. These findings provide significant insight and a fresh perspective into promising novel treatment strategies by up‐regulating HDAC1 in CRF.
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Affiliation(s)
- Jiajun Zhou
- Kidney Department, Yijishan Hospital of Wannan Medical College, Wuhu, China
| | - Han Zhou
- Queen Mary College of Nanchang University, Nanchang, China
| | - Caixin Liu
- Clinical Laboratory, Yijishan Hospital of Wannan Medical College, Wuhu, China
| | - Lin Huang
- Kidney Department, Yijishan Hospital of Wannan Medical College, Wuhu, China
| | - Dongmei Lu
- Kidney Department, Yijishan Hospital of Wannan Medical College, Wuhu, China
| | - Chaoqing Gao
- Kidney Department, Yijishan Hospital of Wannan Medical College, Wuhu, China
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13
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Hesp AC, Schaub JA, Prasad PV, Vallon V, Laverman GD, Bjornstad P, van Raalte DH. The role of renal hypoxia in the pathogenesis of diabetic kidney disease: a promising target for newer renoprotective agents including SGLT2 inhibitors? Kidney Int 2020; 98:579-589. [PMID: 32739206 DOI: 10.1016/j.kint.2020.02.041] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 02/06/2020] [Accepted: 02/26/2020] [Indexed: 12/17/2022]
Abstract
Diabetic kidney disease is the most common cause of end-stage kidney disease and poses a major global health problem. Finding new, safe, and effective strategies to halt this disease has proven to be challenging. In part that is because the underlying mechanisms are complex and not fully understood. However, in recent years, evidence has accumulated suggesting that chronic hypoxia may be the primary pathophysiological pathway driving diabetic kidney disease and chronic kidney disease of other etiologies and was called the chronic hypoxia hypothesis. Hypoxia is the result of a mismatch between oxygen delivery and oxygen demand. The primary determinant of oxygen delivery is renal perfusion (blood flow per tissue mass), whereas the main driver of oxygen demand is active sodium reabsorption. Diabetes mellitus is thought to compromise the oxygen balance by impairing oxygen delivery owing to hyperglycemia-associated microvascular damage and exacerbate oxygen demand owing to increased sodium reabsorption as a result of sodium-glucose cotransporter upregulation and glomerular hyperfiltration. The resultant hypoxic injury creates a vicious cycle of capillary damage, inflammation, deposition of the extracellular matrix, and, ultimately, fibrosis and nephron loss. This review will frame the role of chronic hypoxia in the pathogenesis of diabetic kidney disease and its prospect as a promising therapeutic target. We will outline the cellular mechanisms of hypoxia and evidence for renal hypoxia in animal and human studies. In addition, we will highlight the promise of newer imaging modalities including blood oxygenation level-dependent magnetic resonance imaging and discuss salutary interventions such as sodium-glucose cotransporter 2 inhibition that (may) protect the kidney through amelioration of renal hypoxia.
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Affiliation(s)
- Anne C Hesp
- Diabetes Center, Department of Internal Medicine, Amsterdam University Medical Centers, location VUMC, Amsterdam, The Netherlands.
| | - Jennifer A Schaub
- Division of Nephrology, University of Michigan, Ann Arbor, Michigan, USA
| | - Pottumarthi V Prasad
- Department of Radiology, NorthShore University Health System, Evanston, Illinois, USA; Pritzker School of Medicine, University of Chicago, Chicago, Illinois, USA
| | - Volker Vallon
- Department of Medicine, University of California San Diego and Veterans Affairs San Diego Healthcare System, San Diego, California, USA
| | - Gozewijn D Laverman
- Department of Internal Medicine, Ziekenhuis Groep Twente, Almelo, The Netherlands
| | - Petter Bjornstad
- Department of Medicine, Division of Nephrology, and Section of Endocrinology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Daniël H van Raalte
- Diabetes Center, Department of Internal Medicine, Amsterdam University Medical Centers, location VUMC, Amsterdam, The Netherlands
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14
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Brankovic M, Akkerhuis KM, Hoorn EJ, van Boven N, van den Berge JC, Constantinescu A, Brugts J, van Ramshorst J, Germans T, Hillege H, Boersma E, Umans V, Kardys I. Renal tubular damage and worsening renal function in chronic heart failure: Clinical determinants and relation to prognosis (Bio-SHiFT study). Clin Cardiol 2020; 43:630-638. [PMID: 32298007 PMCID: PMC7298997 DOI: 10.1002/clc.23359] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 03/06/2020] [Accepted: 03/09/2020] [Indexed: 12/18/2022] Open
Abstract
Background It is uncertain that chronic heart failure (CHF) patients are susceptible to renal tubular damage with that of worsening renal function (WRF) preceding clinical outcomes. Hypothesis Changes in tubular damage biomarkers are stronger predictors of subsequent clinical events than changes in creatinine (Cr), and both have different clinical determinants. Methods During 2.2 years, we repeatedly simultaneously collected a median of 9 blood and 8 urine samples per patient in 263 CHF patients. We determined the slopes (rates of change) of the biomarker trajectories for plasma (Cr) and urinary tubular damage biomarkers N‐acetyl‐β‐d‐glucosaminidase (NAG), and kidney‐injury‐molecule (KIM)‐1. The degree of tubular injury was ranked according to NAG and KIM‐1 slopes: increase in neither, increase in either, or increase in both; WRF was defined as increasing Cr slope. The composite endpoint comprised HF‐hospitalization, cardiac death, left ventricular assist device placement, and heart transplantation. Results Higher baseline NT‐proBNP and lower eGFR predicted more severe tubular damage (adjusted odds ratio, adj. OR [95%CI, 95% confidence interval] per doubling NT‐proBNP: 1.26 [1.07‐1.49]; per 10 mL/min/1.73 m2 eGFR decrease 1.16 [1.03‐1.31]). Higher loop diuretic doses, lower aldosterone antagonist doses, and higher eGFR predicted WRF (furosemide per 40 mg increase: 1.32 [1.08‐1.62]; spironolactone per 25 mg decrease: 1.76 [1.07‐2.89]; per 10 mL/min/1.73 m2 eGFR increase: 1.40 [1.20‐1.63]). WRF and higher rank of tubular injury individually entailed higher risk of the composite endpoint (adjusted hazard ratios, adj. HR [95%CI]: WRF 1.9 [1.1‐3.4], tubular 8.4 [2.6‐27.9]; when combined risk was highest 15.0 [2.0‐111.0]). Conclusion Slopes of tubular damage and WRF biomarkers had different clinical determinants. Both predicted clinical outcome, but this association was stronger for tubular injury. Prognostic effects of both appeared independent and additive.
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Affiliation(s)
- Milos Brankovic
- Department of Cardiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - K Martijn Akkerhuis
- Department of Cardiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Ewout J Hoorn
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Nick van Boven
- Department of Cardiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Jan C van den Berge
- Department of Cardiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | - Jasper Brugts
- Department of Cardiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Jan van Ramshorst
- Department of Cardiology, Noordwest Ziekenhuisgroep, Alkmaar, The Netherlands
| | - Tjeerd Germans
- Department of Cardiology, Noordwest Ziekenhuisgroep, Alkmaar, The Netherlands
| | - Hans Hillege
- Department of Epidemiology, University Medical Center Groningen, Groningen, The Netherlands
| | - Eric Boersma
- Department of Cardiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Victor Umans
- Department of Cardiology, Noordwest Ziekenhuisgroep, Alkmaar, The Netherlands
| | - Isabella Kardys
- Department of Cardiology, Erasmus Medical Center, Rotterdam, The Netherlands
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15
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Identifying Synergistic Mechanisms of Multiple Ingredients in Shuangbai Tablets against Proteinuria by Virtual Screening and a Network Pharmacology Approach. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2020; 2020:1027271. [PMID: 32025234 PMCID: PMC6984745 DOI: 10.1155/2020/1027271] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 11/08/2019] [Accepted: 11/29/2019] [Indexed: 02/07/2023]
Abstract
Shuangbai Tablets (SBT), a traditional herbal mixture, has shown substantial clinical efficacy. However, a systematic mechanism of its active ingredients and pharmacological mechanisms of action against proteinuria continues being lacking. A network pharmacology approach was effectual in discovering the relationship of multiple ingredients and targets of the herbal mixture. This study aimed to identify key targets, major active ingredients, and pathways of SBT against proteinuria by network pharmacology approach combined with thin layer chromatography (TLC). Human phenotype (HP) disease analysis, gene ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and molecular docking were used in this study. To this end, a total of 48 candidate targets of 118 active ingredients of SBT were identified. Network analysis showed PTGS2, ESR1, and NOS2 to be the three key targets, and beta-sitosterol, quercetin, and berberine were the three major active ingredients; among them one of the major active ingredients, quercetin, was discriminated by TLC. These results of the functional enrichment analysis indicated that the most relevant disease including these 48 candidate proteins is proteinuria, SBT treated proteinuria by sympathetically regulating multiple biological pathways, such as the HIF-1, RAS, AGE-RAGE, and VEGF signaling pathways. Additionally, molecular docking validation suggested that major active ingredients of SBT were capable of binding to HIF-1A and VEGFA of the main pathways. Consequently, key targets, major active ingredients, and pathways based on data analysis of SBT against proteinuria were systematically identified confirming its utility and providing a new drug against proteinuria.
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16
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Ullah MM, Ow CPC, Hilliard Krause LM, Evans RG. Renal oxygenation during the early stages of adenine-induced chronic kidney disease. Am J Physiol Renal Physiol 2019; 317:F1189-F1200. [DOI: 10.1152/ajprenal.00253.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
To assess whether renal hypoxia is an early event in adenine-induced chronic kidney disease, adenine (100 mg) or its vehicle was administered to male Sprague-Dawley rats by daily oral gavage for 7 days. Kidney oxygenation was assessed by 1) blood oximetry and Clark electrode in thiobutabarbital-anesthetized rats, 2) radiotelemetry in unanesthetized rats, and 3) expression of hypoxia-inducible factor (HIF)-1α and HIF-2α protein. After 7 days of treatment, under anesthesia, renal O2 delivery was 51% less, whereas renal O2 consumption was 65% less, in adenine-treated rats than in vehicle-treated rats. Tissue Po2 measured by Clark electrode was similar in the renal cortex but 44% less in the medulla of adenine-treated rats than in that of vehicle-treated rats. In contrast, in unanesthetized rats, both cortical and medullary tissue Po2 measured by radiotelemetry remained stable across 7 days of adenine treatment. Notably, anesthesia and laparotomy led to greater reductions in medullary tissue Po2 measured by radiotelemetry in rats treated with adenine (37%) than in vehicle-treated rats (16%), possibly explaining differences between our observations with Clark electrodes and radiotelemetry. Renal expression of HIF-1α was less after 7 days of adenine treatment than after vehicle treatment, whereas expression of HIF-2α did not differ significantly between the two groups. Renal dysfunction was evident after 7 days of adenine treatment, with glomerular filtration rate 65% less and serum creatinine concentration 183% greater in adenine-treated rats than in vehicle-treated rats. Renal cortical tissue hypoxia may not precede renal dysfunction in adenine-induced chronic kidney disease and so may not be an early pathological feature in this model.
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Affiliation(s)
- Md Mahbub Ullah
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, Victoria, Australia
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Connie P. C. Ow
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, Victoria, Australia
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Lucinda M. Hilliard Krause
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, Victoria, Australia
| | - Roger G. Evans
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, Victoria, Australia
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17
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Rempel LCT, Faustino VD, Foresto-Neto O, Fanelli C, Arias SCA, Moreira GCDS, Nascimento TF, Ávila VF, Malheiros DMAC, Câmara NOS, Fujihara CK, Zatz R. Chronic exposure to hypoxia attenuates renal injury and innate immunity activation in the remnant kidney model. Am J Physiol Renal Physiol 2019; 317:F1285-F1292. [PMID: 31461352 DOI: 10.1152/ajprenal.00367.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Hypoxia is thought to influence the pathogenesis of chronic kidney disease, but direct evidence that prolonged exposure to tissue hypoxia initiates or aggravates chronic kidney disease is lacking. We tested this hypothesis by chronically exposing normal rats and rats with 5/6 nephrectomy (Nx) to hypoxia. In addition, we investigated whether such effect of hypoxia would involve activation of innate immunity. Adult male Munich-Wistar rats underwent Nx (n = 54) or sham surgery (sham; n = 52). Twenty-six sham rats and 26 Nx rats remained in normoxia, whereas 26 sham rats and 28 Nx rats were kept in a normobaric hypoxia chamber (12% O2) for 8 wk. Hypoxia was confirmed by immunohistochemistry for pimonidazole. Hypoxia was confined to the medullary area in sham + normoxia rats and spread to the cortical area in sham + hypoxia rats, without changing the peritubular capillary density. Exposure to hypoxia promoted no renal injury or elevation of the content of IL-1β or Toll-like receptor 4 in sham rats. In Nx, hypoxia also extended to the cortical area without ameliorating the peritubular capillary rarefaction but, unexpectedly, attenuated hypertension, inflammation, innate immunity activation, renal injury, and oxidative stress. The present study, in disagreement with current concepts, shows evidence that hypoxia exerts a renoprotective effect in the Nx model instead of acting as a factor of renal injury. The mechanisms for this unexpected beneficial effect are unclear and may involve NF-κB inhibition, amelioration of oxidative stress, and limitation of angiotensin II production by the renal tissue.
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Affiliation(s)
- Lisienny Campoli Tono Rempel
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Viviane Dias Faustino
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Orestes Foresto-Neto
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Camilla Fanelli
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Simone Costa Alarcon Arias
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | | | - Thalita Fabiana Nascimento
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Victor Ferreira Ávila
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | | | - Niels Olsen Saraiva Câmara
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil.,Laboratory of Transplantation Immunobiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Clarice Kazue Fujihara
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Roberto Zatz
- Renal Division, Department of Clinical Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
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18
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Xie RY, Fang XL, Zheng XB, Lv WZ, Li YJ, Ibrahim Rage H, He QL, Zhu WP, Cui TX. Salidroside and FG-4592 ameliorate high glucose-induced glomerular endothelial cells injury via HIF upregulation. Biomed Pharmacother 2019; 118:109175. [PMID: 31351423 DOI: 10.1016/j.biopha.2019.109175] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 06/21/2019] [Accepted: 06/25/2019] [Indexed: 12/17/2022] Open
Abstract
Increasing research indicates that hyperglycemia plays a crucial role in the progression of diabetic nephropathy (DN); however, effective treatment for preventing or slowing DN progression are seriously lacking. Although salidroside (SAL) has been demonstrated to have a positive anti-diabetic effect, the cellular mechanisms remain unclear. FG-4592, a novel prolyl hydroxylase inhibitor, was used to regulate HIF-1α and HIF-2α expression. The present study aimed to explore the underlying mechanisms of SAL and FG-4592 on high glucose (HG)-induced rat glomerular endothelial cells (rGECs) injury. HG-cultured rGECs were used to induce a diabetic environment. An MTT assay, RT-qPCR, Western blot, flow cytometry, and immunofluorescent staining were performed to investigate the effects of SAL on HG-induced rGECs injury. FG-4592 and SAL protected rGECs against HG-induced injury by increasing cellular viability and reducing the cell apoptosis rate. SAL and FG-4592 downregulated PHD-2 expression and upregulated HIF-1α and HIF-2α expression. In conclusion, our findings suggest that SAL and FG-4592 ameliorate HG-induced rGEC injury by upregulating HIF expression, indicating that SAL and FG-4592 might be favorable for further DN-treatment.
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Affiliation(s)
- Rui-Yan Xie
- Department of Nephrology, the Fifth Affiliated Hospital of Sun Yat-sen University, No.52 Meihua Road, Zhuhai, 519000, China
| | - Xue-Ling Fang
- Department of Nephrology, the Fifth Affiliated Hospital of Sun Yat-sen University, No.52 Meihua Road, Zhuhai, 519000, China
| | - Xiao-Bin Zheng
- Department of Respiratory Medicine, the Fifth Affiliated Hospital of Sun Yat-sen University, No.52 Meihua Road, Zhuhai, 519000, China
| | - Wei-Ze Lv
- Department of Oncology, the Fifth Affiliated Hospital of Sun Yat-sen University, No.52 Meihua Road, Zhuhai, 519000, China
| | - Yi-Jie Li
- Second Department of General Surgery, the Fifth Affiliated Hospital of Sun Yat-sen University, No.52 Meihua Road, Zhuhai, 519000, China
| | - Hamze Ibrahim Rage
- Department of Nephrology, the Fifth Affiliated Hospital of Sun Yat-sen University, No.52 Meihua Road, Zhuhai, 519000, China
| | - Qiao-Lan He
- Department of Nephrology, the Fifth Affiliated Hospital of Sun Yat-sen University, No.52 Meihua Road, Zhuhai, 519000, China
| | - Wei-Ping Zhu
- Department of Nephrology, the Fifth Affiliated Hospital of Sun Yat-sen University, No.52 Meihua Road, Zhuhai, 519000, China.
| | - Tong-Xia Cui
- Department of Nephrology, the Fifth Affiliated Hospital of Sun Yat-sen University, No.52 Meihua Road, Zhuhai, 519000, China.
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19
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Obert LA, Frazier KS. Intrarenal Renin–Angiotensin System Involvement in the Pathogenesis of Chronic Progressive Nephropathy—Bridging the Informational Gap Between Disciplines. Toxicol Pathol 2019; 47:799-816. [DOI: 10.1177/0192623319861367] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Chronic progressive nephropathy (CPN) is the most commonly encountered spontaneous background finding in laboratory rodents. Various theories on its pathogenesis have been proposed, but there is a paucity of data regarding specific mechanisms or physiologic pathways involved in early CPN development. The current CPN mechanism of action for tumorigenesis is largely based on its associated increase in tubular cell proliferation without regard to preceding subcellular degenerative changes. Combing through the published literature from multiple biology disciplines provided insight into the preceding cellular events. Mechanistic pathways involved in the progressive age-related decline in rodent kidney function and several key inflexion points have been identified. These critical pathway factors were then connected using data from renal models from multiple rodent strains, other species, and mechanistic work in humans to form a cohesive picture of pathways and protein interactions. Abundant data linked similar renal pathologies to local events involving hypoxia (hypoxia-inducible factor 1α), altered intrarenal renin–angiotensin system (RAS), oxidative stress (nitric oxide), and pro-inflammatory pathways (transforming growth factor β), with positive feedback loops and downstream effectors amplifying the injury and promoting scarring. Intrarenal RAS alterations seem to be central to all these events and may be critical to CPN development and progression.
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20
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Morrell GR, Jeong EK, Shi X, Zhang L, Lee VSC. Continuous prospectively navigated multi-echo GRE for improved BOLD imaging of the kidneys. NMR IN BIOMEDICINE 2019; 32:e4078. [PMID: 30811061 PMCID: PMC6476650 DOI: 10.1002/nbm.4078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 01/08/2019] [Accepted: 01/09/2019] [Indexed: 06/09/2023]
Abstract
The objective of this study is to develop improved methods for renal blood oxygenation level dependent (BOLD) imaging. T2* mapping of the kidneys, or renal BOLD imaging, may depict renal oxygen levels and may be valuable as a noninvasive means of following the progression of renal disease. Current renal BOLD data is limited by imaging in a single breath hold, which results in low resolution and low signal-to-noise ratio (SNR). We compare a new free-breathing renal BOLD method with conventional breath-hold BOLD (BH-BOLD). A multi-echo GRE sequence with continuous prospective respiratory navigation and real-time feedback was developed that allows high resolution and high SNR renal BOLD imaging with constant sequence repetition time (TR) during free-breathing BOLD (FB-BOLD). The sequence was evaluated in 10 normal volunteers and compared with conventional BH-BOLD. Scan time for the FB-BOLD sequence was approximately three minutes, compared with 15 seconds for the BH-BOLD sequence. SNR of source images and residual error of T2* fitting were compared between the two methods. The FB-BOLD sequence produced motion-free T2* maps of the kidneys with SNR 1.9 times higher than BH-BOLD images. Residual error of T2* fitting was consistently lower in the right kidney with FB-BOLD (30% less than BH-BOLD) but higher in the left kidney (80% more than BH-BOLD), likely related to placement of the navigator on the right hemidiaphragm. A free-breathing prospectively navigated renal BOLD sequence allows flexible tradeoff between scan time, resolution, and SNR.
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Affiliation(s)
- Glen Robert Morrell
- Utah Center for Advanced Imaging Research, University of Utah Radiology Department, Salt Lake City, Utah, USA
| | - Eun-Kee Jeong
- Utah Center for Advanced Imaging Research, University of Utah Radiology Department, Salt Lake City, Utah, USA
| | - Xianfeng Shi
- Department of Psychiatry, University of Utah School of Medicine, Salt Lake City, Utah, 84108, USA
| | - Lei Zhang
- Utah Center for Advanced Imaging Research, University of Utah Radiology Department, Salt Lake City, Utah, USA
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21
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Carota IA, Kenig-Kozlovsky Y, Onay T, Scott R, Thomson BR, Souma T, Bartlett CS, Li Y, Procissi D, Ramirez V, Yamaguchi S, Tarjus A, Tanna CE, Li C, Eremina V, Vestweber D, Oladipupo SS, Breyer MD, Quaggin SE. Targeting VE-PTP phosphatase protects the kidney from diabetic injury. J Exp Med 2019; 216:936-949. [PMID: 30886059 PMCID: PMC6446875 DOI: 10.1084/jem.20180009] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 11/10/2018] [Accepted: 01/11/2019] [Indexed: 12/18/2022] Open
Abstract
Diabetic nephropathy is a leading cause of kidney failure. VE-PTP phosphatase expression is increased in the endothelium of rodents with diabetes and hypertension. Genetic deletion of VE-PTP reduces kidney injury in diabetic mice, suggesting it may be a therapeutic target. Diabetic nephropathy is a leading cause of end-stage kidney failure. Reduced angiopoietin-TIE2 receptor tyrosine kinase signaling in the vasculature leads to increased vascular permeability, inflammation, and endothelial cell loss and is associated with the development of diabetic complications. Here, we identified a mechanism to explain how TIE2 signaling is attenuated in diabetic animals. Expression of vascular endothelial protein tyrosine phosphatase VE-PTP (also known as PTPRB), which dephosphorylates TIE2, is robustly up-regulated in the renal microvasculature of diabetic rodents, thereby reducing TIE2 activity. Increased VE-PTP expression was dependent on hypoxia-inducible factor transcriptional activity in vivo. Genetic deletion of VE-PTP restored TIE2 activity independent of ligand availability and protected kidney structure and function in a mouse model of severe diabetic nephropathy. Mechanistically, inhibition of VE-PTP activated endothelial nitric oxide synthase and led to nuclear exclusion of the FOXO1 transcription factor, reducing expression of pro-inflammatory and pro-fibrotic gene targets. In sum, we identify inhibition of VE-PTP as a promising therapeutic target to protect the kidney from diabetic injury.
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Affiliation(s)
- Isabel A Carota
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL.,Division of Nephrology/Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL.,Eli Lilly & Company, Biotechnology Discovery Research, Indianapolis, IN
| | - Yael Kenig-Kozlovsky
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL.,Division of Nephrology/Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Tuncer Onay
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL.,Division of Nephrology/Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Rizaldy Scott
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL.,Division of Nephrology/Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Benjamin R Thomson
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL.,Division of Nephrology/Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Tomokazu Souma
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL.,Division of Nephrology/Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Christina S Bartlett
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL.,Division of Nephrology/Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Yanyang Li
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL.,Division of Nephrology/Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Daniele Procissi
- Department of Radiology and Biomedical Engineering, Northwestern University, Feinberg School of Medicine, Chicago, IL
| | - Veronica Ramirez
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL.,Division of Nephrology/Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Shinji Yamaguchi
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL.,Division of Nephrology/Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Antoine Tarjus
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL.,Division of Nephrology/Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Christine E Tanna
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL.,Division of Nephrology/Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Chengjin Li
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Vera Eremina
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | | | | | - Matthew D Breyer
- Eli Lilly & Company, Biotechnology Discovery Research, Indianapolis, IN
| | - Susan E Quaggin
- Feinberg Cardiovascular and Renal Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL .,Division of Nephrology/Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL
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22
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Moonen L, Geryl H, D'Haese PC, Vervaet BA. Short-term dexamethasone treatment transiently, but not permanently, attenuates fibrosis after acute-to-chronic kidney injury. BMC Nephrol 2018; 19:343. [PMID: 30509215 PMCID: PMC6276259 DOI: 10.1186/s12882-018-1151-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 11/23/2018] [Indexed: 01/30/2023] Open
Abstract
Background Acute kidney injury (AKI) is an underestimated, yet important, risk factor for the development of chronic kidney disease (CKD). Persistence of inflammation after a renal ischemic injury has been observed, both in experimental models and patients, and is thought to be an important mechanisms underlying progression of acute-to-chronic renal injury. Temporary suppression of inflammation immediately after AKI might therefore be a good first-line therapeutic strategy towards a better long term outcome. Methods Male C57Bl/6 J mice (Charles River, 10–12 weeks of age) underwent warm (36 °C body temperature) unilateral ischemia-reperfusion of the kidney for 21 min, after which treatment with intraperitoneal injection of the corticosteroid dexamethasone (10 mg/kg) was initiated for 3 weeks. Both at that time point and after an additional 3 week post-treatment follow up period, fibrosis was quantified by collagen I gene expression and immunostaining, as well as gene expression analysis of fibrosis-related genes Tgfβ, Ccn2 (Ctgf), Pai-1 and Ccn3. Furthermore, inflammation was evaluated by Tnfα gene expression and protein expression of the F4/80 macrophage marker and the α-SMA fibroblast marker. Lastly, renal histopathology was quantified by a morphometric analysis of the tubulointerstitial area. Results Treatment with dexamethasone attenuated development of fibrosis, as evidenced by reduced collagen I gene expression and immunostaining, in combination with reduced gene expression of the pro-fibrotic Ccn2 and increased expression of the anti-fibrotic Ccn3. The effects of dexamethasone on renal fibrosis persisted during the 3 week follow up period, as evidenced by stagnation of collagen I deposition in the ischemic kidney, in contrast to vehicle-treatment, where progression of fibrosis was observed. However, expression levels of the pro-fibrotic genes re-approached those of vehicle-treated injured kidneys suggesting that the effects of dexamethasone on fibrosis beyond the treatment period are temporary. Conclusion A short term anti-inflammatory therapy with dexamethasone only transiently attenuates ischemia induced fibrosis. Prolonged or persistent anti-inflammatory treatment seems warranted to achieve long term benefit. Electronic supplementary material The online version of this article (10.1186/s12882-018-1151-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lies Moonen
- Laboratory of Pathophysiology, University of Antwerp, 2160, Antwerpen, Belgium
| | - Hilde Geryl
- Laboratory of Pathophysiology, University of Antwerp, 2160, Antwerpen, Belgium
| | - Patrick C D'Haese
- Laboratory of Pathophysiology, University of Antwerp, 2160, Antwerpen, Belgium
| | - Benjamin A Vervaet
- Laboratory of Pathophysiology, University of Antwerp, 2160, Antwerpen, Belgium.
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23
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Li L, Lai EY, Luo Z, Solis G, Mendonca M, Griendling KK, Wellstein A, Welch WJ, Wilcox CS. High Salt Enhances Reactive Oxygen Species and Angiotensin II Contractions of Glomerular Afferent Arterioles From Mice With Reduced Renal Mass. Hypertension 2018; 72:1208-1216. [PMID: 30354808 PMCID: PMC6221452 DOI: 10.1161/hypertensionaha.118.11354] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 08/10/2018] [Indexed: 12/21/2022]
Abstract
High salt, Ang II (angiotensin II), and reactive oxygen species enhance progression of chronic kidney disease. We tested the hypothesis that a high salt intake generates specific reactive oxygen species to enhance Ang II contractions of afferent arterioles from mice with reduced renal mass (RRM). C57BL/6 mice were subjected to surgical RRM or sham operations and received 6% or 0.4% NaCl salt diet for 3 months. Ang II contractions were measured in perfused afferent arterioles and superoxide (O2-) and hydrogen peroxide (H2O2) by fluorescence microscopy. RRM enhanced the afferent arteriolar gene expression for p47phox and neutrophil oxidase (NOX) 2 and high salt intake in RRM mice enhanced gene expression for angiotensin type 1 receptors, POLDIP2 and NOX4 and reduced catalase. High salt in mice with RRM enhanced arteriolar O2- and H2O2 generation and maximal contractions to Ang II (10-6 mol/L) that were dependent on O2- because they were prevented by gene deletion of p47phox and on H2O2 because they were prevented by transgenic smooth muscle cell expression of catalase (tgCAT-SMC) and POLDIP2 gene deletion. Three months of tempol normalized arteriolar reactive oxygen species and Ang II contractions. However, arteriolar contractions to lower concentrations of Ang II (10-8 to 10-11 mol/L) were paradoxically inhibited by H2O2 and POLDIP2. In conclusion, both O2- from p47phox/NOX2 and H2O2 from NOX4/POLDIP2 enhance maximal arteriolar Ang II contractions from RRM mice during high salt, but H2O2 and NOX4/POLDIP2 reduce the sensitivity to lower concentrations of Ang II by >100-fold. Tempol prevents all of these changes in function.
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Affiliation(s)
- Lingli Li
- Division of Nephrology and Hypertension, and Hypertension Research Center, Georgetown University, Washington, DC
| | - En Yin Lai
- Division of Nephrology and Hypertension, and Hypertension Research Center, Georgetown University, Washington, DC
- Department of Physiology, Zhejiang University School of Medicine, Hangzhou China
| | - Zaiming Luo
- Division of Nephrology and Hypertension, and Hypertension Research Center, Georgetown University, Washington, DC
| | - Glenn Solis
- Division of Nephrology and Hypertension, and Hypertension Research Center, Georgetown University, Washington, DC
| | - Margarida Mendonca
- Division of Nephrology and Hypertension, and Hypertension Research Center, Georgetown University, Washington, DC
| | - Kathy K. Griendling
- Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta
| | - Anton Wellstein
- Lombardi Cancer Center, Georgetown University, Washington DC
| | - William J. Welch
- Division of Nephrology and Hypertension, and Hypertension Research Center, Georgetown University, Washington, DC
| | - Christopher S. Wilcox
- Division of Nephrology and Hypertension, and Hypertension Research Center, Georgetown University, Washington, DC
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24
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Xu X, Palmer SL, Lin X, Li W, Chen K, Yan F, Li X. Diffusion-weighted imaging and pathology of chronic kidney disease: initial study. Abdom Radiol (NY) 2018; 43:1749-1755. [PMID: 29110054 DOI: 10.1007/s00261-017-1362-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE To investigate the value of diffusion-weighted imaging (DWI) for assessing histopathologic changes observed in chronic kidney disease (CKD). METHODS Fifty-two patients with CKD underwent DWI before renal biopsy. The renal apparent diffusion coefficient (ADC) values and histopathologic changes were analyzed. The pathologic changes were scored using a semi-quantitative method (no lesion as 0, mild lesion as 1, moderate lesion as 2, and severe lesion as 3). The relationships between renal histopathologic scores, types, classification, and right renal ADCs were analyzed using ANOVA and Pearson's or Spearman's correlation tests. RESULTS Negative correlations were found between the right renal ADCs and scores of tubulointerstitial lesions (r = - 0.354, P = 0.012), the severity of tubular atrophy (r = - 0.439, P = 0.002), and the severity of interstitial fibrosis (r = - 0.272, P = 0.049). There were no correlations between the ADCs and scores of glomeruli and peritubular vessel lesions (P > 0.05). There were significant differences among groups based on pathology types (P = 0.009). There was no significant relationship between renal ADCs and the pathologic classification (P > 0.05). CONCLUSIONS DWI may be helpful to detect tubulointerstitial injury, including tubular atrophy and interstitial fibrosis. DWI may have the potential to serve as an effective auxiliary method to help nephrologists to evaluate patients with CKD.
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25
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Yang WQ, Mou S, Xu L, Li FH, Li HL. Prediction of Tubulointerstitial Injury in Chronic Kidney Disease Using a Non-Invasive Model: Combination of Renal Sonography and Laboratory Biomarkers. ULTRASOUND IN MEDICINE & BIOLOGY 2018; 44:941-948. [PMID: 29503020 DOI: 10.1016/j.ultrasmedbio.2018.01.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 12/08/2017] [Accepted: 01/23/2018] [Indexed: 06/08/2023]
Abstract
The goal of the study described here was to evaluate the degree of tubulointerstitial injury in patients with chronic kidney disease (CKD) using a more accurate model that combines renal sonographic parameters and laboratory biomarkers. A total of 308 patients were enrolled. The study protocol included conventional ultrasound, contrast-enhanced ultrasonography and renal biopsy. CKD patients were divided into normal and mild (≤25%), moderate (26%-50%) and severe (>50%) tubulointerstitial injury groups. We created a model comprising peak intensity, time to peak, urinary retinol-binding protein and β2-microglobulin that could discriminate severe (>50%) tubulointerstitial injury. The area under the receiver operating characteristic curve of this model was 0.832, which had better accuracy than other individual indexes, and the sensitivity and specificity were 74.2% and 82.8%, respectively. Therefore, this model may be used to evaluate the severity of tubulointerstitial injury and may have the potential to serve as an effective auxiliary method to help nephrologists evaluate patients with CKD.
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Affiliation(s)
- Wen-Qi Yang
- Department of Ultrasound, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Shan Mou
- Department of Nephrology, Molecular Cell Lab for Kidney Disease, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Li Xu
- Department of Ultrasound, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Feng-Hua Li
- Department of Ultrasound, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Hong-Li Li
- Department of Ultrasound, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
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26
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Kumar S. Cellular and molecular pathways of renal repair after acute kidney injury. Kidney Int 2018; 93:27-40. [PMID: 29291820 DOI: 10.1016/j.kint.2017.07.030] [Citation(s) in RCA: 158] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 07/23/2017] [Accepted: 07/31/2017] [Indexed: 12/31/2022]
Abstract
The acutely injured mammalian kidney mounts a cellular and molecular response to repair itself. However, in patchy regions such intrinsic processes are impaired and dysregulated leading to chronic kidney disease. Currently, no therapy exists to treat established acute kidney injury per se. Strategies to augment human endogenous repair processes and retard associated profibrotic responses are urgently required. Recent studies have identified injury-induced activation of the intrinsic molecular driver of epithelial regeneration and induction of partial epithelial to the mesenchymal state, respectively. Activation of key developmental transcription factors drive such processes; however, whether these recruit comparable gene regulatory networks with target genes similar to those in nephrogenesis is unclear. Extensive complex molecular cross-talk between the nephron epithelia and immune, interstitial, and endothelial cells regulate renal recovery. In vitro-based M1/M2 macrophage subtypes have been increasingly linked to renal repair; however, the precise contribution of in vivo macrophage plasticity to repair responses is poorly understood. Endothelial cell-pericyte intimacy, balance of the angiocrine/antiangiocrine system, and endothelial cell-regulated inflammatory processes have an impact on renal recovery and fibrosis. Close scrutiny of cellular and molecular pathways in repairing human kidneys is imperative for the identification of promising therapeutic targets and biomarker of human renal repair processes.
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Affiliation(s)
- Sanjeev Kumar
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.
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27
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Conway BN, Badders AN, Costacou T, Arthur JM, Innes KE. Perfluoroalkyl substances and kidney function in chronic kidney disease, anemia, and diabetes. Diabetes Metab Syndr Obes 2018; 11:707-716. [PMID: 30532572 PMCID: PMC6244585 DOI: 10.2147/dmso.s173809] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Anemia often complicates chronic kidney disease (CKD), leading to insufficient tissue oxygenation and hypoxic injury, the factor thought to underlie progression from CKD to renal failure. Perfluorocarbons are potent oxygen transporters used in organ preservation and synthetic blood development. Data are scarce on their relationship with kidney function, especially in diabetes where anemia and hypoxia are more prevalent. We investigated the relationship of perfluoroalkyl acids (PFAS) with kidney function and variation by diabetes and anemia status. METHODS Data on 53,650 adults (5,210 with diabetes) were obtained from the C8 Health Project. CKD was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. Four PFAS were investigated: perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid, perfluorooctane sulfonate, and perfluorononanoic acid. FINDINGS Each PFAS was positively associated with eGFR among those with CKD or anemia; this was the strongest among those with both CKD and anemia, followed by those with CKD uncomplicated by anemia. These relationships were more pronounced among those with diabetes (all P<0.01). In the absence of both CKD and anemia, PFAS was inversely associated with eGFR. Among persons with both anemia and diabetes, when further stratified by CKD stage, compared to an eGFR <30, ORs (95% CI) for being in the eGFR ≥ 90, 60-89, 45-59, and 30-45 range, respectively, were 3.20 (2.00-5.13), 2.64 (1.83-3.80), 3.18 (2.17-4.67), and 1.99 (1.38-2.86) for each ng/dL increase in PFHxS. Results were similar for each PFAS. INTERPRETATION PFAS are inversely associated with kidney function in CKD and diabetes, with a stronger relation observed when anemia is present.
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Affiliation(s)
- Baqiyyah N Conway
- Department of Epidemiology, School of Public Health, West Virginia University, Morgantown, WV, USA,
- Department of Community Health, School of Rural and Community Health, University of Texas Health Science Center at Tyler, Tyler, TX, USA,
| | - Ashley N Badders
- Department of Epidemiology, School of Public Health, West Virginia University, Morgantown, WV, USA,
- Department of Biostatistics, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tina Costacou
- Department of Epidemiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - John M Arthur
- Department of Internal Medicine, Division of Nephrology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Kim E Innes
- Department of Epidemiology, School of Public Health, West Virginia University, Morgantown, WV, USA,
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28
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Morrell GR, Zhang JL, Lee VS. Magnetic Resonance Imaging of the Fibrotic Kidney. J Am Soc Nephrol 2017; 28:2564-2570. [PMID: 28784699 DOI: 10.1681/asn.2016101089] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Magnetic resonance imaging (MRI) has been used for many years for anatomic evaluation of the kidney. Recently developed methods attempt to go beyond anatomy to give information about the health and function of the kidneys. Several methods, including diffusion-weighted MRI, renal blood oxygen level-dependent MRI, renal MR elastography, and renal susceptibility imaging, show promise for providing unique insight into kidney function and severity of fibrosis. However, substantial limitations in accuracy and practicality limit the immediate clinical application of each method. Further development and improvement are necessary to achieve the ideal of a noninvasive image-based measure of renal fibrosis. Our brief review provides a short explanation of these emerging MRI methods and outlines the promising initial results obtained with each as well as current limitations and barriers to clinical implementation.
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Affiliation(s)
- Glen R Morrell
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah
| | - Jeff L Zhang
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah
| | - Vivian S Lee
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah
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29
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Liu ZZ, Bullen A, Li Y, Singh P. Renal Oxygenation in the Pathophysiology of Chronic Kidney Disease. Front Physiol 2017; 8:385. [PMID: 28701959 PMCID: PMC5487476 DOI: 10.3389/fphys.2017.00385] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 05/23/2017] [Indexed: 12/19/2022] Open
Abstract
Chronic kidney disease (CKD) is a significant health problem associated with high morbidity and mortality. Despite significant research into various pathways involved in the pathophysiology of CKD, the therapeutic options are limited in diabetes and hypertension induced CKD to blood pressure control, hyperglycemia management (in diabetic nephropathy) and reduction of proteinuria, mainly with renin-angiotensin blockade therapy. Recently, renal oxygenation in pathophysiology of CKD progression has received a lot of interest. Several advances have been made in our understanding of the determinants and regulators of renal oxygenation in normal and diseased kidneys. The goal of this review is to discuss the alterations in renal oxygenation (delivery, consumption and tissue oxygen tension) in pre-clinical and clinical studies in diabetic and hypertensive CKD along with the underlying mechanisms and potential therapeutic options.
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Affiliation(s)
- Zhi Zhao Liu
- Division of Nephrology-Hypertension, University of California San Diego School of Medicine, VA San Diego Healthcare SystemSan Diego, CA, United States
| | - Alexander Bullen
- Division of Nephrology-Hypertension, University of California San Diego School of Medicine, VA San Diego Healthcare SystemSan Diego, CA, United States
| | - Ying Li
- Division of Nephrology-Hypertension, University of California San Diego School of Medicine, VA San Diego Healthcare SystemSan Diego, CA, United States
| | - Prabhleen Singh
- Division of Nephrology-Hypertension, University of California San Diego School of Medicine, VA San Diego Healthcare SystemSan Diego, CA, United States
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30
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Williams AN, Conway BN. Effect of high density lipoprotein cholesterol on the relationship of serum iron and hemoglobin with kidney function in diabetes. J Diabetes Complications 2017; 31:958-963. [PMID: 28410926 PMCID: PMC5560583 DOI: 10.1016/j.jdiacomp.2017.03.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/20/2017] [Accepted: 03/25/2017] [Indexed: 01/09/2023]
Abstract
Findings of increased hemoglobin inside the HDL proteome among persons with diabetes who have haptoglobin 2-2 genotype suggest that iron-induced lipid peroxidation may be involved in diabetic kidney disease. We investigated the relationships of serum hemoglobin and iron with kidney function, and whether this varied by level of HDLc, in 5296 adults with and 49,161 without diabetes. Estimated eGFR was our marker of kidney function. Hemoglobin was positively associated with eGFR among those with diabetes and inversely among those without diabetes (interaction p-value <0.0001). Iron was inversely associated with eGFR regardless of diabetes status. When stratified by median HDLc and median hemoglobin, among persons with diabetes mean eGFR was highest in those with high hemoglobin and low HDLc and lowest in those with both low hemoglobin and low HDLc. This divergent relationship was not observed in the non-diabetic population. In contrast to hemoglobin, high iron and low HDLc were associated with a lower mean eGFR regardless of diabetes status. Our data suggest that among persons with diabetes, both hemoglobin and iron are harmful to kidney function at high levels. Our data also suggest that HDLc may play a role in the relationship of high hemoglobin in kidney function in diabetes.
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Affiliation(s)
- Ashley N Williams
- Department of Epidemiology, West Virginia University, Morgantown, WV
| | - Baqiyyah N Conway
- Department of Epidemiology, West Virginia University, Morgantown, WV.
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31
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Saad A, Dietz AB, Herrmann SMS, Hickson LJ, Glockner JF, McKusick MA, Misra S, Bjarnason H, Armstrong AS, Gastineau DA, Lerman LO, Textor SC. Autologous Mesenchymal Stem Cells Increase Cortical Perfusion in Renovascular Disease. J Am Soc Nephrol 2017; 28:2777-2785. [PMID: 28461553 DOI: 10.1681/asn.2017020151] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 03/24/2017] [Indexed: 01/12/2023] Open
Abstract
Atherosclerotic renovascular disease (RVD) reduces renal blood flow (RBF) and GFR and accelerates poststenotic kidney (STK) tissue injury. Preclinical studies indicate that mesenchymal stem cells (MSCs) can stimulate angiogenesis and modify immune function in experimental RVD. We assessed the safety and efficacy of adding intra-arterial autologous adipose-derived MSCs into STK to standardized medical treatment in human subjects without revascularization. The intervention group (n=14) received a single infusion of MSC (1.0 × 105 or 2.5 × 105 cells/kg; n=7 each) plus standardized medical treatment; the medical treatment only group (n=14) included subjects matched for age, kidney function, and stenosis severity. We measured cortical and medullary volumes, perfusion, and RBF using multidetector computed tomography. We assessed tissue oxygenation by blood oxygen level-dependent MRI and GFR by iothalamate clearance. MSC infusions were well tolerated. Three months after infusion, cortical perfusion and RBF rose in the STK (151.8-185.5 ml/min, P=0.01); contralateral kidney RBF increased (212.7-271.8 ml/min, P=0.01); and STK renal hypoxia (percentage of the whole kidney with R2*>30/s) decreased (12.1% [interquartile range, 3.3%-17.8%] to 6.8% [interquartile range, 1.8%-12.9%], P=0.04). No changes in RBF occurred in medical treatment only subjects. Single-kidney GFR remained stable after MSC but fell in the medical treatment only group (-3% versus -24%, P=0.04). This first-in-man dose-escalation study provides evidence of safety of intra-arterial infusion of autologous MSCs in patients with RVD. MSC infusion without main renal artery revascularization associated with increased renal tissue oxygenation and cortical blood flow.
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Affiliation(s)
- Ahmed Saad
- Divisions of *Nephrology and Hypertension and
| | | | | | | | | | | | - Sanjay Misra
- Interventional Radiology, Mayo Clinic, Rochester, Minnesota
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Maekawa H, Inagi R. Stress Signal Network between Hypoxia and ER Stress in Chronic Kidney Disease. Front Physiol 2017; 8:74. [PMID: 28228736 PMCID: PMC5296310 DOI: 10.3389/fphys.2017.00074] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 01/26/2017] [Indexed: 11/24/2022] Open
Abstract
Chronic kidney disease (CKD) is characterized by an irreversible decrease in kidney function and induction of various metabolic dysfunctions. Accumulated findings reveal that chronic hypoxic stress and endoplasmic reticulum (ER) stress are involved in a range of pathogenic conditions, including the progression of CKD. Because of the presence of an arteriovenous oxygen shunt, the kidney is thought to be susceptible to hypoxia. Chronic kidney hypoxia is induced by a number of pathogenic conditions, including renal ischemia, reduced peritubular capillary, and tubulointerstitial fibrosis. The ER is an organelle which helps maintain the quality of proteins through the unfolded protein response (UPR) pathway, and ER dysfunction associated with maladaptive UPR activation is named ER stress. ER stress is reported to be related to some of the effects of pathogenesis in kidney, particularly in the podocyte slit diaphragm and tubulointerstitium. Furthermore, chronic hypoxia mediates ER stress in blood vessel endothelial cells and tubulointerstitium via several mechanisms, including oxidative stress, epigenetic alteration, lipid metabolism, and the AKT pathway. In summary, a growing consensus considers that these stresses interact via complicated stress signal networks, which leads to the exacerbation of CKD (Figure 1). This stress signal network might be a target for interventions aimed at ameliorating CKD.
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Affiliation(s)
- Hiroshi Maekawa
- Division of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine Tokyo, Japan
| | - Reiko Inagi
- Division of Chronic Kidney Disease Pathophysiology, University of Tokyo Graduate School of Medicine Tokyo, Japan
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33
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Liu M, Ning X, Li R, Yang Z, Yang X, Sun S, Qian Q. Signalling pathways involved in hypoxia-induced renal fibrosis. J Cell Mol Med 2017; 21:1248-1259. [PMID: 28097825 PMCID: PMC5487923 DOI: 10.1111/jcmm.13060] [Citation(s) in RCA: 161] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 11/18/2016] [Indexed: 12/23/2022] Open
Abstract
Renal fibrosis is the common pathological hallmark of progressive chronic kidney disease (CKD) with diverse aetiologies. Recent researches have highlighted the critical role of hypoxia during the development of renal fibrosis as a final common pathway in end‐stage kidney disease (ESKD), which joints the scientist's attention recently to exploit the molecular mechanism underlying hypoxia‐induced renal fibrogenesis. The scaring formation is a multilayered cellular response and involves the regulation of multiple hypoxia‐inducible signalling pathways and complex interactive networks. Therefore, this review will focus on the signalling pathways involved in hypoxia‐induced pathogenesis of interstitial fibrosis, including pathways mediated by HIF, TGF‐β, Notch, PKC/ERK, PI3K/Akt, NF‐κB, Ang II/ROS and microRNAs. Roles of molecules such as IL‐6, IL‐18, KIM‐1 and ADO are also reviewed. A comprehensive understanding of the roles that these hypoxia‐responsive signalling pathways and molecules play in the context of renal fibrosis will provide a foundation towards revealing the underlying mechanisms of progression of CKD and identifying novel therapeutic targets. In the future, promising new effective therapy against hypoxic effects may be successfully translated into the clinic to alleviate renal fibrosis and inhibit the progression of CKD.
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Affiliation(s)
- Minna Liu
- Department of Nephrology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China.,State Key Laboratory of Cancer Biology, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Xiaoxuan Ning
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Rong Li
- Department of Nephrology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Zhen Yang
- Department of Nephrology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China.,State Key Laboratory of Cancer Biology, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Xiaoxia Yang
- Department of Nephrology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China.,State Key Laboratory of Cancer Biology, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Shiren Sun
- Department of Nephrology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Qi Qian
- Department of Medicine, Division of Nephrology and hypertension, Mayo Clinic College of Medicine, Mayo Graduate School, Rochester, MN, USA
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34
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Lu W, Kang J, Hu K, Tang S, Zhou X, Yu S, Xu L. Angiotensin-(1-7) relieved renal injury induced by chronic intermittent hypoxia in rats by reducing inflammation, oxidative stress and fibrosis. ACTA ACUST UNITED AC 2017; 50:e5594. [PMID: 28076452 PMCID: PMC5264539 DOI: 10.1590/1414-431x20165594] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 10/25/2016] [Indexed: 11/25/2022]
Abstract
We aimed to study the renal injury and hypertension induced by chronic intermittent
hypoxia (CIH) and the protective effects mediated by angiotensin 1-7 [Ang(1-7)]. We
randomly assigned 32 male Sprague-Dawley rats (body weight 180-200 g) to normoxia
control, CIH, Ang(1-7)-treated normoxia, and Ang(1-7)-treated CIH groups. Systolic
blood pressure (SBP) was monitored at the start and end of each week. Renal
sympathetic nerve activity (RSNA) was recorded. CTGF and TGF-β were detected by
immunohistochemistry and western blotting. Tissue parameters of oxidative stress were
also determined. In addition, renal levels of interleukin-6, tumor necrosis factor-α,
nitrotyrosine, and hypoxia-inducible factor-1α were determined by
immunohistochemistry, immunoblotting, and ELISA. TUNEL assay results and cleaved
caspase 3 and 12 were also determined. Ang(1-7) induced a reduction in SBP together
with a restoration of RSNA in the rat model of CIH. Ang(1-7) treatment also
suppressed the production of reactive oxygen species, reduced renal tissue
inflammation, ameliorated mesangial expansion, and decreased renal fibrosis. Thus,
Ang(1-7) treatment exerted renoprotective effects on CIH-induced renal injury and was
associated with a reduction of oxidative stress, inflammation and fibrosis. Ang(1-7)
might therefore represent a promising therapy for obstructive sleep apnea-related
hypertension and renal injury.
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Affiliation(s)
- W Lu
- Division of Respiratory Disease, Renmin Hospital of Wuhan University, Wuhan, China
| | - J Kang
- Division of Respiratory Disease, Renmin Hospital of Wuhan University, Wuhan, China
| | - K Hu
- Division of Respiratory Disease, Renmin Hospital of Wuhan University, Wuhan, China
| | - S Tang
- Division of Respiratory Disease, Renmin Hospital of Wuhan University, Wuhan, China
| | - X Zhou
- Division of Respiratory Disease, Renmin Hospital of Wuhan University, Wuhan, China
| | - S Yu
- Division of Respiratory Disease, Renmin Hospital of Wuhan University, Wuhan, China
| | - L Xu
- Division of Respiratory Disease, Renmin Hospital of Wuhan University, Wuhan, China
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35
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Wang C, Zhao K, Zhang R, Jiang L, Wang R, Zhang X, Wang H, Jin L, Zhang J, Wang X, Fang J. Evaluation of renal oxygenation change under the influence of carbogen breathing using a dynamic R 2 , R 2 ' and R 2 * quantification approach. NMR IN BIOMEDICINE 2016; 29:1601-1607. [PMID: 27670144 DOI: 10.1002/nbm.3625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 08/03/2016] [Accepted: 08/22/2016] [Indexed: 06/06/2023]
Abstract
The purpose of this study is to demonstrate the feasibility of dynamic renal R2 /R2 '/R2 * measurements based on a method, denoted psMASE-ME, in which a periodic 180° pulse-shifting multi-echo asymmetric spin echo (psMASE) sequence, combined with a moving estimation (ME) strategy, is adopted. Following approval by the institutional animal care and use committee, a block design of respiratory challenge with interleaved air and carbogen (97% O2 , 3% CO2 ) breathing was employed in nine rabbits. Parametrical R2 /R2 '/R2 * maps were computed and average R2 /R2 '/R2 * values were measured in regions of interest in the renal medulla and cortex. Bland-Altman plots showed good agreement between the proposed method and reference standards of multi-echo spin echo and multi-echo gradient echo sequences. Renal R2 , R2 ' and R2 * decreased significantly from 16.2 ± 4.4 s-1 , 9.8 ± 5.2 s-1 and 25.9 ± 5.0 s-1 to 14.9 ± 4.4 s-1 (p < 0.05), 8.5 ± 4.1 s-1 (p < 0.05) and 23.4 ± 4.8 s-1 (p < 0.05) in the cortex when switching the gas mixture from room air to carbogen. In the renal medulla, R2 , R2 ' and R2 * also decreased significantly from 12.9 ± 4.7 s-1 , 15.1 ± 5.8 s-1 and 27.9 ± 5.3 s-1 to 11.8 ± 4.5 s-1 (p < 0.05), 14.2 ± 4.2 s-1 (p < 0.05) and 25.8 ± 5.1 s-1 (p < 0.05). No statistically significant differences in relative R2 , R2 ' and R2 * changes were observed between the cortex and medulla (p = 0.72 for R2 , p = 0.39 for R2 ' and p = 0.61 for R2 *). The psMASE-ME method for dynamic renal R2 /R2 '/R2 * measurements, together with the respiratory challenge, has potential use in the evaluation of renal oxygenation in many renal diseases.
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Affiliation(s)
- Chengyan Wang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Kai Zhao
- Department of Radiology, Peking University First Hospital, Beijing, China
| | - Rui Zhang
- College of Engineering, Peking University, Beijing, China
| | - Li Jiang
- Philips Healthcare, Suzhou, Jiangsu, China
| | - Rui Wang
- Department of Radiology, Peking University First Hospital, Beijing, China
| | - Xiaodong Zhang
- Department of Radiology, Peking University First Hospital, Beijing, China
| | - He Wang
- Philips Healthcare, Suzhou, Jiangsu, China
| | - Lixin Jin
- Philips Healthcare, Suzhou, Jiangsu, China
| | - Jue Zhang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.
- College of Engineering, Peking University, Beijing, China.
| | - Xiaoying Wang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.
- Department of Radiology, Peking University First Hospital, Beijing, China.
| | - Jing Fang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- College of Engineering, Peking University, Beijing, China
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36
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Darby IA, Hewitson TD. Hypoxia in tissue repair and fibrosis. Cell Tissue Res 2016; 365:553-62. [DOI: 10.1007/s00441-016-2461-3] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 06/23/2016] [Indexed: 12/23/2022]
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37
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Muta K, Obata Y, Oka S, Abe S, Minami K, Kitamura M, Endo D, Koji T, Nishino T. Curcumin ameliorates nephrosclerosis via suppression of histone acetylation independent of hypertension. Nephrol Dial Transplant 2016; 31:1615-23. [DOI: 10.1093/ndt/gfw036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 01/31/2016] [Indexed: 01/10/2023] Open
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38
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Ferenbach DA, Bonventre JV. Acute kidney injury and chronic kidney disease: From the laboratory to the clinic. Nephrol Ther 2016; 12 Suppl 1:S41-8. [PMID: 26972097 DOI: 10.1016/j.nephro.2016.02.005] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Chronic kidney disease and acute kidney injury have traditionally been considered as separate entities with different etiologies. This view has changed in recent years, with chronic kidney disease recognized as a major risk factor for the development of new acute kidney injury, and acute kidney injury now accepted to lead to de novo or accelerated chronic and end stage kidney diseases. Patients with existing chronic kidney disease appear to be less able to mount a complete 'adaptive' repair after acute insults, and instead repair maladaptively, with accelerated fibrosis and rates of renal functional decline. This article reviews the epidemiological studies in man that have demonstrated the links between these two processes. We also examine clinical and experimental research in areas of importance to both acute and chronic disease: acute and chronic renal injury to the vasculature, the pericyte and leukocyte populations, the signaling pathways implicated in injury and repair, and the impact of cellular stress and increased levels of growth arrested and senescent cells. The importance and therapeutic potential raised by these processes for acute and chronic injury are discussed.
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Affiliation(s)
- David A Ferenbach
- Renal Division and Biomedical Engineering Division, Brigham and Women's Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA; Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Joseph V Bonventre
- Renal Division and Biomedical Engineering Division, Brigham and Women's Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA; Harvard-Massachusetts Institute of Technology, Division of Health Sciences and Technology, Cambridge, Massachusetts, USA; Harvard Stem Cell Institute, Cambridge, Massachusetts, USA.
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39
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Fu Q, Colgan SP, Shelley CS. Hypoxia: The Force that Drives Chronic Kidney Disease. Clin Med Res 2016; 14:15-39. [PMID: 26847481 PMCID: PMC4851450 DOI: 10.3121/cmr.2015.1282] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 09/30/2015] [Indexed: 12/15/2022]
Abstract
In the United States the prevalence of end-stage renal disease (ESRD) reached epidemic proportions in 2012 with over 600,000 patients being treated. The rates of ESRD among the elderly are disproportionally high. Consequently, as life expectancy increases and the baby-boom generation reaches retirement age, the already heavy burden imposed by ESRD on the US health care system is set to increase dramatically. ESRD represents the terminal stage of chronic kidney disease (CKD). A large body of evidence indicating that CKD is driven by renal tissue hypoxia has led to the development of therapeutic strategies that increase kidney oxygenation and the contention that chronic hypoxia is the final common pathway to end-stage renal failure. Numerous studies have demonstrated that one of the most potent means by which hypoxic conditions within the kidney produce CKD is by inducing a sustained inflammatory attack by infiltrating leukocytes. Indispensable to this attack is the acquisition by leukocytes of an adhesive phenotype. It was thought that this process resulted exclusively from leukocytes responding to cytokines released from ischemic renal endothelium. However, recently it has been demonstrated that leukocytes also become activated independent of the hypoxic response of endothelial cells. It was found that this endothelium-independent mechanism involves leukocytes directly sensing hypoxia and responding by transcriptional induction of the genes that encode the β2-integrin family of adhesion molecules. This induction likely maintains the long-term inflammation by which hypoxia drives the pathogenesis of CKD. Consequently, targeting these transcriptional mechanisms would appear to represent a promising new therapeutic strategy.
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Affiliation(s)
- Qiangwei Fu
- Kabara Cancer Research Institute, La Crosse, WI
| | - Sean P Colgan
- Mucosal Inflammation Program and University of Colorado School of Medicine, Aurora, CO
| | - Carl Simon Shelley
- University of Wisconsin School of Medicine and Public Health, Madison, WI
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40
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Wang C, Zhang R, Wang R, Jiang L, Zhang X, Wang H, Zhao K, Jin L, Zhang J, Wang X, Fang J. Noninvasive measurement of renal oxygen extraction fraction under the influence of respiratory challenge. J Magn Reson Imaging 2016; 44:230-7. [PMID: 26800848 DOI: 10.1002/jmri.25163] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 01/04/2016] [Indexed: 12/12/2022] Open
Affiliation(s)
- Chengyan Wang
- Academy for Advanced Interdisciplinary Studies; Peking University; Beijing PR China
| | - Rui Zhang
- College of Engineering; Peking University; Beijing PR China
| | - Rui Wang
- Department of Radiology; Peking University First Hospital; Beijing PR China
| | - Li Jiang
- Philips Healthcare; Suzhou Jiangsu PR China
| | - Xiaodong Zhang
- Department of Radiology; Peking University First Hospital; Beijing PR China
| | - He Wang
- Philips Healthcare; Suzhou Jiangsu PR China
| | - Kai Zhao
- Department of Radiology; Peking University First Hospital; Beijing PR China
| | - Lixin Jin
- Philips Healthcare; Suzhou Jiangsu PR China
| | - Jue Zhang
- Academy for Advanced Interdisciplinary Studies; Peking University; Beijing PR China
- College of Engineering; Peking University; Beijing PR China
| | - Xiaoying Wang
- Academy for Advanced Interdisciplinary Studies; Peking University; Beijing PR China
- Department of Radiology; Peking University First Hospital; Beijing PR China
| | - Jing Fang
- Academy for Advanced Interdisciplinary Studies; Peking University; Beijing PR China
- College of Engineering; Peking University; Beijing PR China
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41
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Li H, Satriano J, Thomas JL, Miyamoto S, Sharma K, Pastor-Soler NM, Hallows KR, Singh P. Interactions between HIF-1α and AMPK in the regulation of cellular hypoxia adaptation in chronic kidney disease. Am J Physiol Renal Physiol 2015; 309:F414-28. [PMID: 26136559 DOI: 10.1152/ajprenal.00463.2014] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 06/22/2015] [Indexed: 12/16/2022] Open
Abstract
Renal hypoxia contributes to chronic kidney disease (CKD) progression, as validated in experimental and human CKD. In the early stages, increased oxygen consumption causes oxygen demand/supply mismatch, leading to hypoxia. Hence, early targeting of the determinants and regulators of oxygen consumption in CKD may alter the disease course before permanent damage ensues. Here, we focus on hypoxia inducible factor-1α (HIF-1α) and AMP-activated protein kinase (AMPK) and on the mechanisms by which they may facilitate cellular hypoxia adaptation. We found that HIF-1α activation in the subtotal nephrectomy (STN) model of CKD limits protein synthesis, inhibits apoptosis, and activates autophagy, presumably for improved cell survival. AMPK activation was diminished in the STN kidney and was remarkably restored by HIF-1α activation, demonstrating a novel role for HIF-1α in the regulation of AMPK activity. We also investigated the independent and combined effects of HIF-1α and AMPK on cell survival and death pathways by utilizing pharmacological and knockdown approaches in cell culture models. We found that the effect of HIF-1α activation on autophagy is independent of AMPK, but on apoptosis it is partially AMPK dependent. The effects of HIF-1α and AMPK activation on inhibiting protein synthesis via the mTOR pathway appear to be additive. These various effects were also observed under hypoxic conditions. In conclusion, HIF-1α and AMPK appear to be linked at a molecular level and may act as components of a concerted cellular response to hypoxic stress in the pathophysiology of CKD.
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Affiliation(s)
- Hui Li
- Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Joseph Satriano
- Division of Nephrology and Hypertension, Department of Medicine, University of California and Veterans Affairs San Diego Healthcare System, San Diego, California; and
| | - Joanna L Thomas
- Division of Nephrology and Hypertension, Department of Medicine, University of California and Veterans Affairs San Diego Healthcare System, San Diego, California; and
| | - Satoshi Miyamoto
- Division of Nephrology and Hypertension, Department of Medicine, University of California and Veterans Affairs San Diego Healthcare System, San Diego, California; and Center for Renal Translational Medicine, University of California, San Diego, California
| | - Kumar Sharma
- Division of Nephrology and Hypertension, Department of Medicine, University of California and Veterans Affairs San Diego Healthcare System, San Diego, California; and Center for Renal Translational Medicine, University of California, San Diego, California
| | - Núria M Pastor-Soler
- Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Kenneth R Hallows
- Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Prabhleen Singh
- Division of Nephrology and Hypertension, Department of Medicine, University of California and Veterans Affairs San Diego Healthcare System, San Diego, California; and
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42
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Niles DJ, Gordon JW, Fain SB. Effect of anesthesia on renal R2 * measured by blood oxygen level-dependent MRI. NMR IN BIOMEDICINE 2015; 28:811-817. [PMID: 25951135 PMCID: PMC4478156 DOI: 10.1002/nbm.3314] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 02/03/2015] [Accepted: 04/03/2015] [Indexed: 06/04/2023]
Abstract
Blood oxygen level-dependent (BOLD) MRI is increasingly being used to assess renal tissue oxygenation during disease based on the transverse relaxation rate (R2 *). In preclinical small animal models, the requisite use of anesthesia during imaging may lead to functional changes which influence R2 * and confound results. The purpose of this study was to evaluate the effects of four common anesthetic compounds on renal R2 * in healthy mice. Five female ICR mice were imaged with BOLD MRI approximately 25 min after induction with isoflurane (Iso; 1% or 1.5%, delivered in 100% O2 ), ketamine/xylazine (KX), sodium pentobarbital (PB) or 2,2,2-tribromoethanol (TBE). A significant effect of anesthetic agent on R2 * was observed in all tissue layers of the kidney, including the cortex, outer stripe of the outer medulla (OSOM), inner stripe of the outer medulla (ISOM) and inner medulla (IM). Pairwise significant differences in R2 * between specific agents were found in the cortex, OSOM and ISOM, with the largest difference observed in the ISOM between 1.5% Iso (26.6 ± 1.7 s(-1) ) and KX (66.0 ± 7.1 s(-1) ). The difference between 1% Iso and KX in the ISOM was not abolished when KX was administered with supplemental 100% O2 or when 1% Iso was delivered in 21% O2 , indicating that the fraction of inspired oxygen did not account for the observed differences. Our results indicate that the choice of anesthesia has a large influence on the observed R2 * in mouse kidney, and anesthetic effects must be considered in the design and interpretation of renal BOLD MRI studies.
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Affiliation(s)
- David J. Niles
- Department of Medical Physics, University of Wisconsin, Madison, WI, United States
| | - Jeremy W. Gordon
- Department of Medical Physics, University of Wisconsin, Madison, WI, United States
| | - Sean B. Fain
- Department of Medical Physics, University of Wisconsin, Madison, WI, United States
- Department of Radiology, University of Wisconsin Madison, WI, United States
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, United States
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43
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Howarth AR, Conway BR, Bailey MA. Vascular and inflammatory actions of P2X receptors in renal injury. Auton Neurosci 2015; 191:135-40. [PMID: 25998687 DOI: 10.1016/j.autneu.2015.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
P2 purinergic receptors are activated by extracellular ATP and subserve a plethora of roles in the body, including metabolism, inflammation and neuronal signalling. This review focuses on renal purinergic receptors and how different roles that they play may contribute to renal dysfunction and the progression of chronic kidney disease. Numerous studies have linked P2 receptors, particularly the P2X4R and P2X7R subtypes, to kidney injury and damage. However, the mechanisms underlying this association are not fully defined. Several studies show that activation of P2X4R and particularly P2X7R can have a pro-inflammatory effect, causing or exacerbating damage to renal tissue. However, clinical trials aiming to utilise P2X7R antagonists to treat inflammatory disease have been unsuccessful, and it is possible that other mechanisms besides inflammation tie P2X7R activation to disease progression. In this context, purinergic signalling is also involved in the control of vascular tone and our recent studies suggest that activation of P2X4R/P2X7R causes renal vascular dysfunction and contributes to chronic kidney disease. This brief review aims to summarise the complementary inflammatory and vascular roles of P2X receptors in the kidney, with emphasis on the subtypes P2X4R and P27XR, and how each contributes to and presents therapeutic targets in the progression of chronic kidney disease.
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Affiliation(s)
- Amelia R Howarth
- British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom
| | - Bryan R Conway
- British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom
| | - Matthew A Bailey
- British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, United Kingdom.
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44
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Basile DP, Yoder MC. Renal endothelial dysfunction in acute kidney ischemia reperfusion injury. Cardiovasc Hematol Disord Drug Targets 2015; 14:3-14. [PMID: 25088124 DOI: 10.2174/1871529x1401140724093505] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 05/15/2014] [Accepted: 05/30/2014] [Indexed: 01/11/2023]
Abstract
Acute kidney injury is associated with alterations in vascular tone that contribute to an overall reduction in GFR. Studies in animal models indicate that ischemia triggers alterations in endothelial function that contribute significantly to the overall degree and severity of a kidney injury. Putative mediators of vasoconstriction that may contribute to the initial loss of renal blood flow and GFR are highlighted. In addition, there is discussion of how intrinsic damage to the endothelium impairs homeostatic responses in vascular tone as well as promotes leukocyte adhesion and exacerbating the reduction in renal blood flow. The timing of potential therapies in animal models as they relate to the evolution of AKI, as well as the limitations of such approaches in the clinical setting are discussed. Finally, we discuss how acute kidney injury induces permanent alterations in renal vascular structure. We posit that the cause of the sustained impairment in kidney capillary density results from impaired endothelial growth responses and suggest that this limitation is a primary contributing feature underlying progression of chronic kidney disease.
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Affiliation(s)
| | - Mervin C Yoder
- Department of Cellular & Integrative Physiology, Indiana University School of Medicine, 635 Barnhill Drive, Med Sci 334, Indianapolis, IN 46202, USA.
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Renal primordia activate kidney regenerative events in a rat model of progressive renal disease. PLoS One 2015; 10:e0120235. [PMID: 25811887 PMCID: PMC4374877 DOI: 10.1371/journal.pone.0120235] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 01/22/2015] [Indexed: 11/19/2022] Open
Abstract
New intervention tools for severely damaged kidneys are in great demand to provide patients with a valid alternative to whole organ replacement. For repairing or replacing injured tissues, emerging approaches focus on using stem and progenitor cells. Embryonic kidneys represent an interesting option because, when transplanted to sites such as the renal capsule of healthy animals, they originate new renal structures. Here, we studied whether metanephroi possess developmental capacity when transplanted under the kidney capsule of MWF male rats, a model of spontaneous nephropathy. We found that six weeks post-transplantation, renal primordia developed glomeruli and tubuli able to filter blood and to produce urine in cyst-like structures. Newly developed metanephroi were able to initiate a regenerative-like process in host renal tissues adjacent to the graft in MWF male rats as indicated by an increase in cell proliferation and vascular density, accompanied by mRNA and protein upregulation of VEGF, FGF2, HGF, IGF-1 and Pax-2. The expression of SMP30 and NCAM was induced in tubular cells. Oxidative stress and apoptosis markedly decreased. Our study shows that embryonic kidneys generate functional nephrons when transplanted into animals with severe renal disease and at the same time activate events at least partly mimicking those observed in kidney tissues during renal regeneration.
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46
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Mancina E, Kalenski J, Paschenda P, Beckers C, Bleilevens C, Boor P, Doorschodt BM, Tolba RH. Determination of the Preferred Conditions for the Isolated Perfusion of Porcine Kidneys. Eur Surg Res 2014; 54:44-54. [DOI: 10.1159/000366155] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 07/22/2014] [Indexed: 11/19/2022]
Abstract
Background: The isolated perfused porcine kidney (IPPK) model has been the method of choice for the early preclinical evaluation of kidney graft preservation techniques. The preferred reperfusion conditions have not yet been determined. Here, we examined the effects of pressure- or flow-controlled perfusion and oxygenation by pure oxygen or carbogen (95% O2/5% CO2) on normothermic reperfusion in the IPPK model. Methods: Porcine kidneys were cold-stored for 24 h in histidine-tryptophan-ketoglutarate solution and reperfused for 1 h with normothermic whole blood/Krebs-Henseleit buffer medium (20/80%). Kidneys (n = 5/group) were flow-controlled reperfused with pure oxygen (1 ml/min/g; Flow-O2) or pressure-controlled reperfused (85 mm Hg mean arterial pressure) and oxygenated with either pure oxygen (Pressure-O2) or carbogen (Pressure-O2/CO2). Renal function and damage were assessed during reperfusion and NGAL and HIF-1α levels were analyzed using an ELISA. Results: Pressure-O2 and Pressure-O2/CO2 were associated with significantly better renal hemodynamics and acid-base homeostasis compared to Flow-O2. Urine protein concentrations and the fractional excretion of sodium were lower with both Pressure-O2 and Pressure-O2/CO2 than with Flow-O2. NGAL and HIF-1α levels were also lower with Pressure-O2 and Pressure-O2/CO2 than with Flow-O2. Only Pressure-O2/CO2 could demonstrate a significantly increased urine production compared to Flow-O2. The structural integrity was well preserved in the Pressure-O2 and Pressure-O2/CO2 groups, whereas diffuse and global glomerular destruction was observed in the Flow-O2 group. Conclusion: In the IPPK model, the application of pressure-controlled reperfusion with carbogen oxygenation, and to a lesser extent with pure oxygen, maintained physiological renal function for 1 h, thus providing a reliable and reproducible ex vivo evaluation of kidney preservation quality.
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Juárez-Orozco LE, Szymanski MK, Hillege HL, Kruizinga S, Noordzij W, Koole M, Tio RA, Alexanderson E, Dierckx RAJO, Slart RHJA. Imaging of cardiac and renal perfusion in a rat model with 13N–NH3 micro-PET. Int J Cardiovasc Imaging 2014; 31:213-9. [DOI: 10.1007/s10554-014-0538-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 09/13/2014] [Indexed: 11/30/2022]
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48
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Ichii O, Otsuka-Kanazawa S, Nakamura T, Ueno M, Kon Y, Chen W, Rosenberg AZ, Kopp JB. Podocyte injury caused by indoxyl sulfate, a uremic toxin and aryl-hydrocarbon receptor ligand. PLoS One 2014; 9:e108448. [PMID: 25244654 PMCID: PMC4171541 DOI: 10.1371/journal.pone.0108448] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 08/21/2014] [Indexed: 02/07/2023] Open
Abstract
Indoxyl sulfate is a uremic toxin and a ligand of the aryl-hydrocarbon receptor (AhR), a transcriptional regulator. Elevated serum indoxyl sulfate levels may contribute to progressive kidney disease and associated vascular disease. We asked whether indoxyl sulfate injures podocytes in vivo and in vitro. Mice exposed to indoxyl sulfate for 8 w exhibited prominent tubulointerstitial lesions with vascular damage. Indoxyl sulfate-exposed mice with microalbuminuria showed ischemic changes, while more severely affected mice showed increased mesangial matrix, segmental solidification, and mesangiolysis. In normal mouse kidneys, AhR was predominantly localized to the podocyte nuclei. In mice exposed to indoxyl sulfate for 2 h, isolated glomeruli manifested increased Cyp1a1 expression, indicating AhR activation. After 8 w of indoxyl sulfate, podocytes showed foot process effacement, cytoplasmic vacuoles, and a focal granular and wrinkled pattern of podocin and synaptopodin expression. Furthermore, vimentin and AhR expression in the glomerulus was increased in the indoxyl sulfate-exposed glomeruli compared to controls. Glomerular expression of characteristic podocyte mRNAs was decreased, including Actn4, Cd2ap, Myh9, Nphs1, Nphs2, Podxl, Synpo, and Wt1. In vitro, immortalized-mouse podocytes exhibited AhR nuclear translocation beginning 30 min after 1 mM indoxyl sulfate exposure, and there was increased phospho-Rac1/Cdc42 at 2 h. After exposure to indoxyl sulfate for 24 h, mouse podocytes exhibited a pro-inflammatory phenotype, perturbed actin cytoskeleton, decreased expression of podocyte-specific genes, and decreased cell viability. In immortalized human podocytes, indoxyl sulfate treatment caused cell injury, decreased mRNA expression of podocyte-specific proteins, as well as integrins, collagens, cytoskeletal proteins, and bone morphogenetic proteins, and increased cytokine and chemokine expression. We propose that basal levels of AhR activity regulate podocyte function under normal conditions, and that increased activation of podocyte AhR by indoxyl sulfate contributes to progressive glomerular injury.
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Affiliation(s)
- Osamu Ichii
- Laboratory of Anatomy, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan
- Kidney Disease Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
| | - Saori Otsuka-Kanazawa
- Laboratory of Anatomy, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan
| | - Teppei Nakamura
- Laboratory of Anatomy, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan
- Section of Biological Safety Research, Chitose Laboratory, Japan Food Research Laboratories, Chitose, Japan
| | - Masaaki Ueno
- Section of Biological Safety Research, Chitose Laboratory, Japan Food Research Laboratories, Chitose, Japan
| | - Yasuhiro Kon
- Laboratory of Anatomy, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan
| | - Weiping Chen
- Microarray Core Facility, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Avi Z. Rosenberg
- Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jeffrey B. Kopp
- Kidney Disease Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
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Nordquist L, Friederich-Persson M, Fasching A, Liss P, Shoji K, Nangaku M, Hansell P, Palm F. Activation of hypoxia-inducible factors prevents diabetic nephropathy. J Am Soc Nephrol 2014; 26:328-38. [PMID: 25183809 DOI: 10.1681/asn.2013090990] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Hyperglycemia results in increased oxygen consumption and decreased oxygen tension in the kidney. We tested the hypothesis that activation of hypoxia-inducible factors (HIFs) protects against diabetes-induced alterations in oxygen metabolism and kidney function. Experimental groups consisted of control and streptozotocin-induced diabetic rats treated with or without chronic cobalt chloride to activate HIFs. We elucidated the involvement of oxidative stress by studying the effects of acute administration of the superoxide dismutase mimetic tempol. Compared with controls, diabetic rats displayed tissue hypoxia throughout the kidney, glomerular hyperfiltration, increased oxygen consumption, increased total mitochondrial leak respiration, and decreased tubular sodium transport efficiency. Diabetic kidneys showed proteinuria and tubulointerstitial damage. Cobalt chloride activated HIFs, prevented the diabetes-induced alterations in oxygen metabolism, mitochondrial leak respiration, and kidney function, and reduced proteinuria and tubulointerstitial damage. The beneficial effects of tempol were less pronounced after activation of HIFs, indicating improved oxidative stress status. In conclusion, activation of HIFs prevents diabetes-induced alteration in kidney oxygen metabolism by normalizing glomerular filtration, which reduces tubular electrolyte load, preventing mitochondrial leak respiration and improving tubular transport efficiency. These improvements could be related to reduced oxidative stress and account for the reduced proteinuria and tubulointerstitial damage. Thus, pharmacologic activation of the HIF system may prevent development of diabetic nephropathy.
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Affiliation(s)
- Lina Nordquist
- Division of Integrative Physiology, Department of Medical Cell Biology and
| | | | - Angelica Fasching
- Division of Integrative Physiology, Department of Medical Cell Biology and
| | - Per Liss
- Department of Radiology, Oncology and Radiation Science, Uppsala University, Uppsala, Sweden
| | - Kumi Shoji
- Division of Nephrology and Endocrinology, University of Tokyo School of Medicine, Tokyo, Japan; and
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, University of Tokyo School of Medicine, Tokyo, Japan; and
| | - Peter Hansell
- Division of Integrative Physiology, Department of Medical Cell Biology and
| | - Fredrik Palm
- Division of Integrative Physiology, Department of Medical Cell Biology and Division of Drug Research, Department of Medical and Health Sciences and Center for Medical Image Science and Visualization, Linköping University, Linköping, Sweden
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Origin of myofibroblasts and cellular events triggering fibrosis. Kidney Int 2014; 87:297-307. [PMID: 25162398 DOI: 10.1038/ki.2014.287] [Citation(s) in RCA: 258] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 04/04/2014] [Accepted: 04/10/2014] [Indexed: 01/13/2023]
Abstract
Renal fibrosis is a major hallmark of chronic kidney disease that is considered to be a common end point of various types of renal disease. To date, the biological meaning of fibrosis during the progression of chronic kidney diseases is unknown and possibly depends on the cell type contributing to extracellular matrix production. During the past decade, the origin of myofibroblasts in the kidney has been intensively investigated. Determining the origins of renal myofibroblasts is important because these might account for the heterogeneous characteristics and behaviors of myofibroblasts. Current data strongly suggest that collagen-producing myofibroblasts in the kidney can be derived from various cellular sources. Resident renal fibroblasts and cells of hematopoietic origin migrating into the kidney seem to be the most important ancestors of myofibroblasts. It is likely that both cell types communicate with each other and also with other cell types in the kidney. In this review, we will discuss the current knowledge on the origin of scar-producing myofibroblasts and cellular events triggering fibrosis.
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