1
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Ullah MM, Collett JA, Bacallao RL, Basile DP. Impaired hemodynamic renal reserve response following recovery from established acute kidney injury and improvement by hydrodynamic isotonic fluid delivery. Am J Physiol Renal Physiol 2024; 326:F86-F94. [PMID: 37881874 PMCID: PMC11194053 DOI: 10.1152/ajprenal.00204.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 10/04/2023] [Accepted: 10/18/2023] [Indexed: 10/27/2023] Open
Abstract
Renal reserve capacity may be compromised following recovery from acute kidney injury (AKI) and could be used to identify impaired renal function in the face of restored glomerular filtration rate (GFR) or plasma creatinine. To investigate the loss of hemodynamic renal reserve responses following recovery in a model of AKI, rats were subjected to left unilateral renal ischemia-reperfusion (I/R) injury and contralateral nephrectomy and allowed to recover for 5 wk. Some rats were treated 24 h post-I/R by hydrodynamic isotonic fluid delivery (AKI-HIFD) of saline through the renal vein, previously shown to improve recovery and inflammation relative to control rats that received saline through the vena cava (AKI-VC). At 5 wk after surgery, plasma creatinine and GFR recovered to levels observed in uninephrectomized sham controls. Baseline renal blood flow (RBF) was not different between AKI or sham groups, but infusion of l-arginine (7.5 mg/kg/min) significantly increased RBF in sham controls, whereas the RBF response to l-arginine was significantly reduced in AKI-VC rats relative to sham rats (22.6 ± 2.2% vs. 13.8 ± 1.8%, P < 0.05). RBF responses were partially protected in AKI-HIFD rats relative to AKI-VC rats (17.0 ± 2.2%) and were not significantly different from sham rats. Capillary rarefaction observed in AKI-VC rats was significantly protected in AKI-HIFD rats. There was also a significant increase in T helper 17 cell infiltration and interstitial fibrosis in AKI-VC rats versus sham rats, which was not present in AKI-HIFD rats. These data suggest that recovery from AKI results in impaired hemodynamic reserve and that associated CKD progression may be mitigated by HIFD in the early post-AKI period.NEW & NOTEWORTHY Despite the apparent recovery of renal filtration function following acute kidney injury (AKI) in rats, the renal hemodynamic reserve response is significantly attenuated, suggesting that clinical evaluation of this parameter may provide information on the potential development of chronic kidney disease. Treatments such as hydrodynamic isotonic fluid delivery, or other treatments in the early post-AKI period, could minimize chronic inflammation or loss of microvessels with the potential to promote a more favorable outcome on long-term function.
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Affiliation(s)
- Md Mahbub Ullah
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Jason A Collett
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Robert L Bacallao
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, Indiana, United States
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United States
- Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana, United States
| | - David P Basile
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, Indiana, United States
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2
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Naas S, Schiffer M, Schödel J. Hypoxia and renal fibrosis. Am J Physiol Cell Physiol 2023; 325:C999-C1016. [PMID: 37661918 DOI: 10.1152/ajpcell.00201.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/25/2023] [Accepted: 08/25/2023] [Indexed: 09/05/2023]
Abstract
Renal fibrosis is the final stage of most progressive kidney diseases. Chronic kidney disease (CKD) is associated with high comorbidity and mortality. Thus, preventing fibrosis and thereby preserving kidney function increases the quality of life and prolongs the survival of patients with CKD. Many processes such as inflammation or metabolic stress modulate the progression of kidney fibrosis. Hypoxia has also been implicated in the pathogenesis of renal fibrosis, and oxygen sensing in the kidney is of outstanding importance for the body. The dysregulation of oxygen sensing in the diseased kidney is best exemplified by the loss of stimulation of erythropoietin production from interstitial cells in the fibrotic kidney despite anemia. Furthermore, hypoxia is present in acute or chronic kidney diseases and may affect all cell types present in the kidney including tubular and glomerular cells as well as resident immune cells. Pro- and antifibrotic effects of the transcription factors hypoxia-inducible factors 1 and 2 have been described in a plethora of animal models of acute and chronic kidney diseases, but recent advances in sequencing technologies now allow for novel and deeper insights into the role of hypoxia and its cell type-specific effects on the progression of renal fibrosis, especially in humans. Here, we review existing literature on how hypoxia impacts the development and progression of renal fibrosis.
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Affiliation(s)
- Stephanie Naas
- Department of Nephrology and Hypertension, Uniklinikum Erlangen und Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Mario Schiffer
- Department of Nephrology and Hypertension, Uniklinikum Erlangen und Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Johannes Schödel
- Department of Nephrology and Hypertension, Uniklinikum Erlangen und Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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3
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Ortega-Trejo JA, Bobadilla NA. Is Renal Ischemic Preconditioning an Alternative to Ameliorate the Short- and Long-Term Consequences of Acute Kidney Injury? Int J Mol Sci 2023; 24:ijms24098345. [PMID: 37176051 PMCID: PMC10178892 DOI: 10.3390/ijms24098345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/21/2023] [Accepted: 04/26/2023] [Indexed: 05/15/2023] Open
Abstract
Acute kidney injury (AKI) is a global health problem and has recently been recognized as a risk factor for developing chronic kidney disease (CKD). Unfortunately, there are no effective treatments to reduce or prevent AKI, which results in high morbidity and mortality rates. Ischemic preconditioning (IPC) has emerged as a promising strategy to prevent, to the extent possible, renal tissue from AKI. Several studies have used this strategy, which involves short or long cycles of ischemia/reperfusion (IR) prior to a potential fatal ischemic injury. In most of these studies, IPC was effective at reducing renal damage. Since the first study that showed renoprotection due to IPC, several studies have focused on finding the best strategy to activate correctly and efficiently reparative mechanisms, generating different modalities with promising results. In addition, the studies performing remote IPC, by inducing an ischemic process in distant tissues before a renal IR, are also addressed. Here, we review in detail existing studies on IPC strategies for AKI pathophysiology and the proposed triggering mechanisms that have a positive impact on renal function and structure in animal models of AKI and in humans, as well as the prospects and challenges for its clinical application.
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Affiliation(s)
- Juan Antonio Ortega-Trejo
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Norma A Bobadilla
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
- Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City 14080, Mexico
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4
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Saranya GR, Viswanathan P. Gut microbiota dysbiosis in AKI to CKD transition. Biomed Pharmacother 2023; 161:114447. [PMID: 37002571 DOI: 10.1016/j.biopha.2023.114447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/22/2023] [Accepted: 02/23/2023] [Indexed: 03/05/2023] Open
Abstract
BACKGROUND AND AIM The symptoms of acute kidney injury (AKI) include a sudden drop-in glomerular filtration rate (GFR), a rise in serum creatinine (sCr), blood urea nitrogen (BUN), and electrolytes, which leads to a rapid loss of kidney function. Chronic kidney disease progresses when AKI symptoms persist for over three months or 90 days. Numerous prevalent secondary risk factors, including diabetes, hypertension, obesity, and heart illness, are directly or indirectly linked to the development of AKI and the switch from AKI to CKD. Recently, the change of intestinal bacteria known as "gut dysbiosis" has been linked to distant organ dysfunction, including the heart, lungs, kidneys, and brain. Indirectly or directly, gut dysbiosis contributes to the progression of CKD and AKI. However, the effects of gut dysbiosis and the mechanism of action in the progression from AKI to CKD are unknown or need further investigation. The mechanism by which gut dysbiosis initiates AKI's progression to CKD should be explicitly concerned. The review primarily focuses on the action of gut dysbiosis in kidney disease, the effects of dysbiosis, the characterisation of dysbiosis and its pathogenic products, the various pathogenic routes and mechanism involved in expediting the transition from AKI to CKD. CONCLUSION We identified and briefly reviewed the impacts of dysbiosis in various situations such as hypoxia, mitochondrial induced reactive oxygen species (mtROS), aryl hydrocarbon receptor (AhR) activation and microbiota derived uremic toxemic substances profoundly to push AKI to CKD conditions.
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Affiliation(s)
- G R Saranya
- Renal Research Lab, School of Bio Sciences and Technology, Pearl Research Park, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India
| | - Pragasam Viswanathan
- Renal Research Lab, School of Bio Sciences and Technology, Pearl Research Park, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India.
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5
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Tubular epithelial cells-derived small extracellular vesicle-VEGF-A promotes peritubular capillary repair in ischemic kidney injury. NPJ Regen Med 2022; 7:73. [PMID: 36528739 PMCID: PMC9759551 DOI: 10.1038/s41536-022-00268-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 11/30/2022] [Indexed: 12/23/2022] Open
Abstract
Peritubular capillaries (PTCs) are closely related to renal tubules in structure and function, and both are pivotal regulators in the development and progression of acute kidney injury (AKI). However, the mechanisms that underlie the interaction between PTCs and tubules during AKI remain unclear. Here we explored a new mode of tubulovascular crosstalk mediated by small extracellular vesicles (sEV) after AKI. In response to renal ischemia/reperfusion (I/R) injury, endothelial proliferation of PTCs and tubular expression of vascular endothelial growth factor-A (VEGF-A) were increased, accompanied by a remarkable redistribution of cytoplasmic VEGF-A to the basolateral side of tubular cells. Meanwhile, the secretion mode of VEGF-A was converted in the injured tubular cells, which showed a much greater tendency to secrete VEGF-A via sEV other than the free form. Interestingly, tubular cell-derived VEGF-A-enriched sEV (sEV-VEGF-A) turned out to promote endothelial proliferation which was regulated by VEGF receptors 1 and 2. Furthermore, inhibition of renal sEV secretion by Rab27a knockdown resulted in a significant decrease in the proliferation of peritubular endothelial cells in vivo. Importantly, taking advantage of the newly recognized endogenous repair response of PTCs, exogenous supplementation of VEGF-A + sEV efficiently recused PTC rarefaction, improved renal perfusion, and halted the AKI to CKD transition. Taken together, our study uncovered a novel intrinsic repair response after AKI through renal tubule-PTC crosstalk via sEV-VEGF-A, which could be exploited as a promising therapeutic angiogenesis strategy in diseases with ischemia.
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6
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Nie Y, Wang L, You X, Wang X, Wu J, Zheng Z. Low dimensional nanomaterials for treating acute kidney injury. J Nanobiotechnology 2022; 20:505. [PMID: 36456976 PMCID: PMC9714216 DOI: 10.1186/s12951-022-01712-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 11/15/2022] [Indexed: 12/02/2022] Open
Abstract
Acute kidney injury (AKI) is one of the most common severe complications among hospitalized patients. In the absence of specific drugs to treat AKI, hemodialysis remains the primary clinical treatment for AKI patients. AKI treatment has received significant attention recently due to the excellent drug delivery capabilities of low-dimensional nanomaterials (LDNs) and their unique therapeutic effects. Diverse LDNs have been proposed to treat AKI, with promising results and the potential for future clinical application. This article aims to provide an overview of the pathogenesis of AKI and the recent advances in the treatment of AKI using different types of LDNs. In addition, it is intended to provide theoretical support for the design of LDNs and implications for AKI treatment.
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Affiliation(s)
- Yuanpeng Nie
- Department of Nephrology, Center of Kidney and Urology, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China
| | - Liying Wang
- Department of Hematology, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China
| | - Xinru You
- Department of Pediatrics, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China
| | - Xiaohua Wang
- Bioscience and Biomedical Engineering Thrust, The Hong Kong University of Science and Technology (Guangzhou), Nansha, Guangzhou, 511400, China
| | - Jun Wu
- Department of Hematology, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China.
- Bioscience and Biomedical Engineering Thrust, The Hong Kong University of Science and Technology (Guangzhou), Nansha, Guangzhou, 511400, China.
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong SAR, China.
| | - Zhihua Zheng
- Department of Nephrology, Center of Kidney and Urology, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China.
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7
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Wang Z, Zhang C. From AKI to CKD: Maladaptive Repair and the Underlying Mechanisms. Int J Mol Sci 2022; 23:ijms231810880. [PMID: 36142787 PMCID: PMC9504835 DOI: 10.3390/ijms231810880] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 12/03/2022] Open
Abstract
Acute kidney injury (AKI) is defined as a pathological condition in which the glomerular filtration rate decreases rapidly over a short period of time, resulting in changes in the physiological function and tissue structure of the kidney. An increasing amount of evidence indicates that there is an inseparable relationship between acute kidney injury and chronic kidney disease (CKD). With the progress in research in this area, researchers have found that the recovery of AKI may also result in the occurrence of CKD due to its own maladaptation and other potential mechanisms, which involve endothelial cell injury, inflammatory reactions, progression to fibrosis and other pathways that promote the progress of the disease. Based on these findings, this review summarizes the occurrence and potential mechanisms of maladaptive repair in the progression of AKI to CKD and explores possible treatment strategies in this process so as to provide a reference for the inhibition of the progression of AKI to CKD.
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8
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Ghajar-Rahimi G, Agarwal A. Endothelial KLF11 as a Nephroprotectant in AKI. KIDNEY360 2022; 3:1302-1305. [PMID: 36176668 PMCID: PMC9416841 DOI: 10.34067/kid.0003422022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 06/14/2022] [Indexed: 06/16/2023]
Affiliation(s)
- Gelare Ghajar-Rahimi
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Nephrology Research and Training Center, University of Alabama at Birmingham, Birmingham, Alabama
- Division of Cardiothoracic Surgery, Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama
| | - Anupam Agarwal
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Birmingham Veterans Administration Health Care Services, Birmingham, Alabama
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9
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Li F, Qiao Z, Duan Q, Nevo E. Adaptation of mammals to hypoxia. Animal Model Exp Med 2021; 4:311-318. [PMID: 34977482 PMCID: PMC8690989 DOI: 10.1002/ame2.12189] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 10/27/2021] [Accepted: 10/31/2021] [Indexed: 12/19/2022] Open
Abstract
Oxygen plays a pivotal role in the metabolism and activities of mammals. However, oxygen is restricted in some environments-subterranean burrow systems or habitats at high altitude or deep in the ocean-and this could exert hypoxic stresses such as oxidative damage on organisms living in these environments. In order to cope with these stresses, organisms have evolved specific strategies to adapt to hypoxia, including changes in physiology, gene expression regulation, and genetic mutations. Here, we review how mammals have adapted to the three high-altitude plateaus of the world, the limited oxygen dissolved in deep water habitats, and underground tunnels, with the aim of better understanding the adaptation of mammals to hypoxia.
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Affiliation(s)
- Fang Li
- College of Life Sciences and TechnologyMudanjiang Normal UniversityMudanjiangChina
| | - Zhenglei Qiao
- College of Life Sciences and TechnologyMudanjiang Normal UniversityMudanjiangChina
| | - Qijiao Duan
- College of Natural Resources and EnvironmentSouth China Agriculture UniversityGuangzhouChina
| | - Eviatar Nevo
- Institute of EvolutionUniversity of HaifaHaifaIsrael
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10
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Lan S, Yang B, Migneault F, Turgeon J, Bourgault M, Dieudé M, Cardinal H, Hickey MJ, Patey N, Hébert MJ. Caspase-3-dependent peritubular capillary dysfunction is pivotal for the transition from acute to chronic kidney disease after acute ischemia-reperfusion injury. Am J Physiol Renal Physiol 2021; 321:F335-F351. [PMID: 34338031 DOI: 10.1152/ajprenal.00690.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 07/21/2021] [Indexed: 11/22/2022] Open
Abstract
Ischemia-reperfusion injury (IRI) is a major risk factor for chronic renal failure. Caspase-3, an effector responsible for apoptosis execution, is activated within the peritubular capillary (PTC) in the early stage of IRI-induced acute kidney injury (AKI). Recently, we showed that caspase-3-dependent microvascular rarefaction plays a key role in fibrosis development after mild renal IRI. Here, we further characterized the role of caspase-3 in microvascular dysfunction and progressive renal failure in both mild and severe AKI, by performing unilateral renal artery clamping for 30/60 min with contralateral nephrectomy in wild-type (C57BL/6) or caspase-3-/- mice. In both forms of AKI, caspase-3-/- mice showed better long-term outcomes despite worse initial tubular injury. After 3 wk, they showed reduced PTC injury, decreased PTC collagen deposition and α-smooth muscle actin expression, and lower tubular injury scores compared with wild-type animals. Caspase-3-/- mice with severe IRI also showed better preservation of long-term renal function. Intravital imaging and microcomputed tomography revealed preserved PTC permeability and better terminal capillary density in caspase-3-/- mice. Collectively, these results demonstrate the pivotal importance of caspase-3 in regulating long-term renal function after IRI and establish the predominant role of PTC dysfunction as a major contributor to progressive renal dysfunction.NEW & NOTEWORTHY Our findings demonstrate the pivotal importance of caspase-3 in regulating renal microvascular dysfunction, fibrogenesis, and long-term renal impairment after acute kidney injury induced by ischemia-reperfusion injury. Furthermore, this study establishes the predominant role of peritubular capillary integrity as a major contributor to progressive renal dysfunction after ischemia-reperfusion injury.
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Affiliation(s)
- Shanshan Lan
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada
- Canadian Donation Transplant Research Program, Edmonton, Alberta, Canada
- Université de Montréal, Montreal, Quebec, Canada
| | - Bing Yang
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada
- Canadian Donation Transplant Research Program, Edmonton, Alberta, Canada
- Université de Montréal, Montreal, Quebec, Canada
| | - Francis Migneault
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada
- Canadian Donation Transplant Research Program, Edmonton, Alberta, Canada
| | - Julie Turgeon
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada
- Canadian Donation Transplant Research Program, Edmonton, Alberta, Canada
| | - Maude Bourgault
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada
| | - Mélanie Dieudé
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada
- Canadian Donation Transplant Research Program, Edmonton, Alberta, Canada
- Université de Montréal, Montreal, Quebec, Canada
| | - Héloïse Cardinal
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada
- Canadian Donation Transplant Research Program, Edmonton, Alberta, Canada
- Université de Montréal, Montreal, Quebec, Canada
| | - Michael J Hickey
- Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton, Victoria, Australia
| | - Natacha Patey
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada
- Université de Montréal, Montreal, Quebec, Canada
- Department of Pathology, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada
| | - Marie-Josée Hébert
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada
- Canadian Donation Transplant Research Program, Edmonton, Alberta, Canada
- Université de Montréal, Montreal, Quebec, Canada
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11
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Robinson CH, Jeyakumar N, Luo B, Wald R, Garg AX, Nash DM, McArthur E, Greenberg JH, Askenazi D, Mammen C, Thabane L, Goldstein S, Parekh RS, Zappitelli M, Chanchlani R. Long-Term Kidney Outcomes Following Dialysis-Treated Childhood Acute Kidney Injury: A Population-Based Cohort Study. J Am Soc Nephrol 2021; 32:2005-2019. [PMID: 34039667 PMCID: PMC8455253 DOI: 10.1681/asn.2020111665] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 03/23/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND AKI is common during pediatric hospitalizations and associated with adverse short-term outcomes. However, long-term outcomes among survivors of pediatric AKI who received dialysis remain uncertain. METHODS To determine the long-term risk of kidney failure (defined as receipt of chronic dialysis or kidney transplant) or death over a 22-year period for pediatric survivors of dialysis-treated AKI, we used province-wide health administrative databases to perform a retrospective cohort study of all neonates and children (aged 0-18 years) hospitalized in Ontario, Canada, from April 1, 1996, to March 31, 2017, who survived a dialysis-treated AKI episode. Each AKI survivor was matched to four hospitalized pediatric comparators without dialysis-treated AKI, on the basis of age, sex, and admission year. We reported the incidence of each outcome and performed Cox proportional hazards regression analyses, adjusting for relevant covariates. RESULTS We identified 1688 pediatric dialysis-treated AKI survivors (median age 5 years) and 6752 matched comparators. Among AKI survivors, 53.7% underwent mechanical ventilation and 33.6% had cardiac surgery. During a median 9.6-year follow-up, AKI survivors were at significantly increased risk of a composite outcome of kidney failure or death versus comparators. Death occurred in 113 (6.7%) AKI survivors, 44 (2.6%) developed kidney failure, 174 (12.1%) developed hypertension, 213 (13.1%) developed CKD, and 237 (14.0%) had subsequent AKI. AKI survivors had significantly higher risks of developing CKD and hypertension versus comparators. Risks were greatest in the first year after discharge and gradually decreased over time. CONCLUSIONS Survivors of pediatric dialysis-treated AKI are at higher long-term risks of kidney failure, death, CKD, and hypertension, compared with a matched hospitalized cohort.
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Affiliation(s)
- Cal H. Robinson
- Division of Paediatric Nephrology, Department of Paediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada,Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | | | - Bin Luo
- ICES, London, Ontario, Canada
| | - Ron Wald
- Division of Nephrology, St. Michael’s Hospital and University of Toronto, Toronto, Ontario, Canada
| | | | | | | | - Jason H. Greenberg
- Division of Nephrology, Department of Pediatrics, Yale University, New Haven, Connecticut
| | - David Askenazi
- Division of Pediatric Nephrology, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Cherry Mammen
- Division of Nephrology, Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lehana Thabane
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada,Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, Ontario, Canada,Department of Anesthesia, McMaster University, Hamilton, Ontario, Canada,Biostatistics Unit, St Joseph’s Healthcare, Hamilton, Ontario, Canada
| | - Stuart Goldstein
- Center for Acute Care Nephrology, Cincinnati Children’s Hospital, Cincinnati, Ohio
| | - Rulan S. Parekh
- Division of Paediatric Nephrology, Department of Paediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Michael Zappitelli
- Division of Paediatric Nephrology, Department of Paediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Rahul Chanchlani
- ICES, London, Ontario, Canada,Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, Ontario, Canada,Division of Pediatric Nephrology, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
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12
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Spencer S, Wheeler-Jones C, Elliott J. Hypoxia and chronic kidney disease: Possible mechanisms, therapeutic targets, and relevance to cats. Vet J 2021; 274:105714. [PMID: 34252550 DOI: 10.1016/j.tvjl.2021.105714] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 07/01/2021] [Accepted: 07/06/2021] [Indexed: 10/20/2022]
Abstract
There is mounting evidence that kidney ischaemia/hypoxia plays an important role in feline chronic kidney disease (CKD) development and progression, as well as in human disease and laboratory animal models. Ischaemic acute kidney injury is widely accepted as a cause of CKD in people and data from laboratory species has identified some of the pathways underlying this continuum. Experimental kidney ischaemia in cats results in morphological changes, namely chronic tubulointerstitial inflammation, tubulointerstitial fibrosis, and tubular atrophy, akin to those observed in naturally-occurring CKD. Multiple situations are envisaged that could result in acute or chronic episodes of kidney hypoxia in cats, while risk factors identified in epidemiological studies provide further support that kidney hypoxia contributes to spontaneously occurring feline CKD. This review evaluates the evidence for the role of kidney ischaemia/hypoxia in feline CKD and the proposed mechanisms and consequences of kidney hypoxia. As no effective treatments exist that substantially slow or prevent feline CKD progression, there is a need for novel therapeutic strategies. Targeting kidney hypoxia is one such promising approach, with therapies including those that attenuate the hypoxia-inducible factor (HIF) pathway already being utilised in human CKD.
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Affiliation(s)
- Sarah Spencer
- Comparative Biomedical Sciences, The Royal Veterinary College, Royal College Street, London NW1 0TU, UK.
| | - Caroline Wheeler-Jones
- Comparative Biomedical Sciences, The Royal Veterinary College, Royal College Street, London NW1 0TU, UK
| | - Jonathan Elliott
- Comparative Biomedical Sciences, The Royal Veterinary College, Royal College Street, London NW1 0TU, UK
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13
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Vegfa promoter gene hypermethylation at HIF1α binding site is an early contributor to CKD progression after renal ischemia. Sci Rep 2021; 11:8769. [PMID: 33888767 PMCID: PMC8062449 DOI: 10.1038/s41598-021-88000-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 04/06/2021] [Indexed: 11/08/2022] Open
Abstract
Chronic hypoxia is a major contributor to Chronic Kidney Disease (CKD) after Acute Kidney Injury (AKI). However, the temporal relation between the acute insult and maladaptive renal response to hypoxia remains unclear. In this study, we analyzed the time-course of renal hemodynamics, oxidative stress, inflammation, and fibrosis, as well as epigenetic modifications, with focus on HIF1α/VEGF signaling, in the AKI to CKD transition. Sham-operated, right nephrectomy (UNx), and UNx plus renal ischemia (IR + UNx) groups of rats were included and studied at 1, 2, 3, or 4 months. The IR + UNx group developed CKD characterized by progressive proteinuria, renal dysfunction, tubular proliferation, and fibrosis. At first month post-ischemia, there was a twofold significant increase in oxidative stress and reduction in global DNA methylation that was maintained throughout the study. Hif1α and Vegfa expression were depressed in the first and second-months post-ischemia, and then Hif1α but not Vegfa expression was recovered. Interestingly, hypermethylation of the Vegfa promoter gene at the HIF1α binding site was found, since early stages of the CKD progression. Our findings suggest that renal hypoperfusion, inefficient hypoxic response, increased oxidative stress, DNA hypomethylation, and, Vegfa promoter gene hypermethylation at HIF1α binding site, are early determinants of AKI-to-CKD transition.
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14
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van Wincoop M, de Bijl-Marcus K, Lilien M, van den Hoogen A, Groenendaal F. Effect of therapeutic hypothermia on renal and myocardial function in asphyxiated (near) term neonates: A systematic review and meta-analysis. PLoS One 2021; 16:e0247403. [PMID: 33630895 PMCID: PMC7906340 DOI: 10.1371/journal.pone.0247403] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 02/08/2021] [Indexed: 01/20/2023] Open
Abstract
Background Therapeutic hypothermia (TH) is a well-established neuroprotective therapy applied in (near) term asphyxiated infants. However, little is known regarding the effects of TH on renal and/or myocardial function. Objectives To describe the short- and long-term effects of TH on renal and myocardial function in asphyxiated (near) term neonates. Methods An electronic search strategy incorporating MeSH terms and keywords was performed in October 2019 and updated in June 2020 using PubMed and Cochrane databases. Inclusion criteria consisted of a RCT or observational cohort design, intervention with TH in a setting of perinatal asphyxia and available long-term results on renal and myocardial function. We performed a meta-analysis and heterogeneity and sensitivity analyses using a random effects model. Subgroup analysis was performed on the method of cooling. Results Of the 107 studies identified on renal function, 9 were included. None of the studies investigated the effects of TH on long-term renal function after perinatal asphyxia. The nine included studies described the effect of TH on the incidence of acute kidney injury (AKI) after perinatal asphyxia. Meta-analysis showed a significant difference between the incidence of AKI in neonates treated with TH compared to the control group (RR = 0.81; 95% CI 0.67–0.98; p = 0.03). No studies were found investigating the long-term effects of TH on myocardial function after neonatal asphyxia. Possible short-term beneficial effects were presented in 4 out of 5 identified studies, as observed by significant reductions in cardiac biomarkers and less findings of myocardial dysfunction on ECG and cardiac ultrasound. Conclusions TH in asphyxiated neonates reduces the incidence of AKI, an important risk factor for chronic kidney damage, and thus is potentially renoprotective. No studies were found on the long-term effects of TH on myocardial function. Short-term outcome studies suggest a cardioprotective effect.
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Affiliation(s)
- Maureen van Wincoop
- Department of Neonatology, Wilhelmina Children’s Hospital, University Medical Centre Utrecht and Utrecht University, Utrecht, The Netherlands
| | - Karen de Bijl-Marcus
- Department of Neonatology, Wilhelmina Children’s Hospital, University Medical Centre Utrecht and Utrecht University, Utrecht, The Netherlands
- * E-mail:
| | - Marc Lilien
- Department of Pediatric Nephrology, Wilhelmina Children’s Hospital, University Medical Centre Utrecht and Utrecht University, Utrecht, The Netherlands
| | - Agnes van den Hoogen
- Department of Neonatology, Wilhelmina Children’s Hospital, University Medical Centre Utrecht and Utrecht University, Utrecht, The Netherlands
| | - Floris Groenendaal
- Department of Neonatology, Wilhelmina Children’s Hospital, University Medical Centre Utrecht and Utrecht University, Utrecht, The Netherlands
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15
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Zou J, Yang J, Zhu X, Zhong J, Elshaer A, Matsusaka T, Pastan I, Haase VH, Yang HC, Fogo AB. Stabilization of hypoxia-inducible factor ameliorates glomerular injury sensitization after tubulointerstitial injury. Kidney Int 2020; 99:620-631. [PMID: 33137336 DOI: 10.1016/j.kint.2020.09.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 09/14/2020] [Accepted: 09/17/2020] [Indexed: 12/24/2022]
Abstract
Previously, we found that mild tubulointerstitial injury sensitizes glomeruli to subsequent injury. Here, we evaluated whether stabilization of hypoxia-inducible factor-α (HIF-α), a key regulator of tissue response to hypoxia, ameliorates tubulointerstitial injury and impact on subsequent glomerular injury. Nep25 mice, which express the human CD25 receptor on podocytes under control of the nephrin promotor and develop glomerulosclerosis when a specific toxin is administered were used. Tubulointerstitial injury, evident by week two, was induced by folic acid, and mice were treated with an HIF stabilizer, dimethyloxalylglycine or vehicle from week three to six. Uninephrectomy at week six assessed tubulointerstitial fibrosis. Glomerular injury was induced by podocyte toxin at week seven, and mice were sacrificed ten days later. At week six tubular injury markers normalized but with patchy collagen I and interstitial fibrosis. Pimonidazole staining, a hypoxia marker, was increased by folic acid treatment compared to vehicle while dimethyloxalylglycine stimulated HIF-2α expression and attenuated tubulointerstitial hypoxia. The hematocrit was increased by dimethyloxalylglycine along with downstream effectors of HIF. Tubular epithelial cell injury, inflammation and interstitial fibrosis were improved after dimethyloxalylglycine, with further reduced mortality, interstitial fibrosis, and glomerulosclerosis induced by specific podocyte injury. Thus, our findings indicate that hypoxia contributes to tubular injury and consequent sensitization of glomeruli to injury. Hence, restoring HIFs may blunt this adverse crosstalk of tubules to glomeruli.
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Affiliation(s)
- Jun Zou
- Division of Nephrology, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Jaewon Yang
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Division of Nephrology, Yonsei University Wonju College of Medicine, Wonju, Gangwon, South Korea
| | - Xiaoye Zhu
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Division of Nephrology, Huashan Hospital, Wudan University, Shanghai, China
| | - Jianyong Zhong
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Division of Pediatric Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Ahmed Elshaer
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Taiji Matsusaka
- Institute of Medical Science, Tokai University, Isehara, Japan
| | - Ira Pastan
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Volker H Haase
- Departments of Medicine, Cancer Biology, and Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA; Medicine and Research Services, Department of Veterans Affairs Hospital, Tennessee Valley Healthcare System, Nashville, Tennessee, USA
| | - Hai-Chun Yang
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Division of Pediatric Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Agnes B Fogo
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Division of Pediatric Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
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16
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Ullah MM, Basile DP. Role of Renal Hypoxia in the Progression From Acute Kidney Injury to Chronic Kidney Disease. Semin Nephrol 2020; 39:567-580. [PMID: 31836039 DOI: 10.1016/j.semnephrol.2019.10.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Over the past 20 years, there has been an increased appreciation of the long-term sequelae of acute kidney injury (AKI) and the potential development of chronic kidney disease (CKD). Several pathophysiologic features have been proposed to mediate AKI to CKD progression including maladaptive alterations in tubular, interstitial, inflammatory, and vascular cells. These alterations likely interact to culminate in the progression to CKD. In this article we focus primarily on evidence of vascular rarefaction secondary to AKI, and the potential mechanisms by which rarefaction occurs in relation to other alterations in tubular and interstitial compartments. We further focus on the potential that rarefaction contributes to renal hypoxia. Consideration of the role of hypoxia in AKI to CKD transition focuses on experimental evidence of persistent renal hypoxia after AKI and experimental maneuvers to evaluate the influence of hypoxia, per se, in progressive disease. Finally, consideration of methods to evaluate hypoxia in patients is provided with the suggestion that noninvasive measurement of renal hypoxia may provide insight into progression in post-AKI patients.
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Affiliation(s)
- Md Mahbub Ullah
- Department of Anatomy, Cell Biology and Physiology, Indiana University, Indianapolis, IN
| | - David P Basile
- Department of Medicine, Division of Nephrology, Indiana University, Indianapolis, IN.
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17
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Sugahara M, Tanaka T, Nangaku M. Hypoxia-Inducible Factor and Oxygen Biology in the Kidney. ACTA ACUST UNITED AC 2020; 1:1021-1031. [DOI: 10.34067/kid.0001302020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 07/21/2020] [Indexed: 12/19/2022]
Abstract
Kidney tissue hypoxia is detected in various kidney diseases and is considered to play an important role in the pathophysiology of both AKI and CKD. Because of the characteristic vascular architecture and high energy demand to drive tubular solute transport, the renal medulla is especially prone to hypoxia. Injured kidneys often present capillary rarefaction, inflammation, and fibrosis, which contribute to sustained kidney hypoxia, forming a vicious cycle promoting progressive CKD. Hypoxia-inducible factor (HIF), a transcription factor responsible for cellular adaptation to hypoxia, is generally considered to protect against AKI. On the contrary, consequences of sustained HIF activation in CKD may be either protective, neutral, or detrimental. The kidney outcomes seem to be affected by various factors, such as cell types in which HIF is activated/inhibited, disease models, balance between two HIF isoforms, and time and methods of intervention. This suggests multifaceted functions of HIF and highlights the importance of understanding its role within each specific context. Prolyl-hydroxylase domain (PHD) inhibitors, which act as HIF stabilizers, have been developed to treat anemia of CKD. Although many preclinical studies demonstrated renoprotective effects of PHD inhibitors in CKD models, there may be some situations in which they lead to deleterious effects. Further studies are needed to identify patients who would gain additional benefits from PHD inhibitors and those who may need to avoid them.
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18
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Gao J, Liu Y, Jiang B, Cao W, Kan Y, Chen W, Ding M, Zhang G, Zhang B, Xi K, Jia X, Zhao X, Guo H. Phenylenediamine-Based Carbon Nanodots Alleviate Acute Kidney Injury via Preferential Renal Accumulation and Antioxidant Capacity. ACS APPLIED MATERIALS & INTERFACES 2020; 12:31745-31756. [PMID: 32571010 DOI: 10.1021/acsami.0c05041] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
As a reactive oxygen species (ROS)-promoted disease, acute kidney injury (AKI) is associated with high mortality and morbidity, but no effective pharmacological treatment is available. Kidney-targeted and ROS-reactive antioxidants are in urgent demand for AKI treatment. A promising nanotechnology-based strategy for targeting renal tubules offers new perspectives for AKI treatment but remains challenging because of the glomerular filtration barrier, which requires ultrasmall-sized therapeutics for penetration and filtration. Here, we fabricated four potential antioxidative carbon nanodots (CNDs) with ultrasmall size. After balancing the antioxidant properties and biocompatibility, m-phenylenediamine-based CNDs (PDA-CNDs) were chosen for further research. PDA-CNDs demonstrated remarkable antioxidant properties for scavenging multiple toxic free radicals, enabling efficient protection of cells under various oxidative stresses in vitro. Moreover, fluorescence imaging revealed that PDA-CNDs preferentially accumulated in the injured kidney of mice with ischemia-reperfusion (IR)-induced AKI. Blood renal function tests and kidney tissue staining revealed the therapeutic efficacy of PDA-CNDs for AKI in both the murine IR-induced AKI model and cisplatin-induced AKI model. Collectively, this is the first study revealing that specific rationally designed CNDs could be a promising pharmacological treatment for AKI induced by ROS.
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Affiliation(s)
- Jie Gao
- Department of Urology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Institute of Urology Nanjing University, No. 321 Zhongshan Road, Nanjing 210008, Jiangsu, China
| | - Yanfeng Liu
- School of Chemistry & Chemical Engineering, Nanjing University, No. 163 Xianlin Road, Nanjing 210008, Jiangsu, China
| | - Bo Jiang
- Department of Urology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Institute of Urology Nanjing University, No. 321 Zhongshan Road, Nanjing 210008, Jiangsu, China
| | - Wenmin Cao
- Department of Urology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Institute of Urology Nanjing University, No. 321 Zhongshan Road, Nanjing 210008, Jiangsu, China
| | - Yansheng Kan
- Department of Urology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Institute of Urology Nanjing University, No. 321 Zhongshan Road, Nanjing 210008, Jiangsu, China
| | - Wei Chen
- Department of Urology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Institute of Urology Nanjing University, No. 321 Zhongshan Road, Nanjing 210008, Jiangsu, China
| | - Meng Ding
- Department of Urology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Institute of Urology Nanjing University, No. 321 Zhongshan Road, Nanjing 210008, Jiangsu, China
| | - Guiyang Zhang
- School of Chemistry & Chemical Engineering, Nanjing University, No. 163 Xianlin Road, Nanjing 210008, Jiangsu, China
| | - Bowen Zhang
- School of Chemistry & Chemical Engineering, Nanjing University, No. 163 Xianlin Road, Nanjing 210008, Jiangsu, China
| | - Kai Xi
- School of Chemistry & Chemical Engineering, Nanjing University, No. 163 Xianlin Road, Nanjing 210008, Jiangsu, China
| | - Xudong Jia
- School of Chemistry & Chemical Engineering, Nanjing University, No. 163 Xianlin Road, Nanjing 210008, Jiangsu, China
| | - Xiaozhi Zhao
- Department of Urology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Institute of Urology Nanjing University, No. 321 Zhongshan Road, Nanjing 210008, Jiangsu, China
| | - Hongqian Guo
- Department of Urology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Institute of Urology Nanjing University, No. 321 Zhongshan Road, Nanjing 210008, Jiangsu, China
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19
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Conversion of extracellular ATP into adenosine: a master switch in renal health and disease. Nat Rev Nephrol 2020; 16:509-524. [PMID: 32641760 DOI: 10.1038/s41581-020-0304-7] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/01/2020] [Indexed: 12/22/2022]
Abstract
ATP and its ultimate degradation product adenosine are potent extracellular signalling molecules that elicit a variety of pathophysiological functions in the kidney through the activation of P2 and P1 purinergic receptors, respectively. Extracellular purines can modulate immune responses, balancing inflammatory processes and immunosuppression; indeed, alterations in extracellular nucleotide and adenosine signalling determine outcomes of inflammation and healing processes. The functional activities of ectonucleotidases such as CD39 and CD73, which hydrolyse pro-inflammatory ATP to generate immunosuppressive adenosine, are therefore pivotal in acute inflammation. Protracted inflammation may result in aberrant adenosinergic signalling, which serves to sustain inflammasome activation and worsen fibrotic reactions. Alterations in the expression of ectonucleotidases on various immune cells, such as regulatory T cells and macrophages, as well as components of the renal vasculature, control purinergic receptor-mediated effects on target tissues within the kidney. The role of CD39 as a rheostat that can have an impact on purinergic signalling in both acute and chronic inflammation is increasingly supported by the literature, as detailed in this Review. Better understanding of these purinergic processes and development of novel drugs targeting these pathways could lead to effective therapies for the management of acute and chronic kidney disease.
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20
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Parmaksız E, Torun Parmaksız E. Reversibility of microalbuminuria with continuous positive airway pressure treatment in obstructive sleep apnea syndrome. Int Urol Nephrol 2020; 52:1719-1724. [PMID: 32488755 DOI: 10.1007/s11255-020-02519-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 05/25/2020] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Microalbuminuria is an early marker of kidney damage and an early predictor and risk factor for cardiovascular diseases. We aimed to evaluate the association between albuminuria levels in different severity obstructive sleep apnea syndrome (OSAS) cases and to find out the efficacy of CPAP treatment on microalbuminuria. MATERIALS AND METHODS We conducted a prospective study on subjects who underwent polysomnography. The polysomnographic data were recorded to establish the presence and severity of OSAS. The blood and urine samples were taken both at the time of diagnosis and 3 months after CPAP therapy. The relationship between the severity of OSAS and microalbuminuria and the effect of CPAP treatment on microalbuminuria were evaluated. RESULTS The study population consisted of 449 subjects. Better compliance to CPAP was associated with significantly reduced levels of microlbuminuria. Urinary albumin/creatinine was increased in severe cases, but the difference was not statistically significant. In the non-compliant group, microalbumin/creatinine ratio was 25.24 prior to initiation of CPAP treatment and 28.36 at the third month control visit (p = 0.25). In the compliant group, microalbumin/creatinine ratio was 49.71 prior to initiation of CPAP treatment and 22.30 at the third month control visit (p = 0.04). CONCLUSION Our study demonstrated that good compliance to CPAP therapy is associated with a decrease in microalbuminuria. Patients who used CPAP regularly had a significant decline in albumin/creatinine ratio after 3 months of CPAP therapy.
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Affiliation(s)
- Ergün Parmaksız
- Nephrology Clinic, Istanbul Kartal Dr. Lütfi Kirdar Training and Research Hospital, Kartal, Istanbul, Turkey.
| | - Elif Torun Parmaksız
- Department of Chest Diseases, Istanbul Kartal Dr. Lütfi Kirdar Training and Research Hospital, Istanbul, Turkey
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21
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Li S, Lin Q, Shao X, Zhu X, Wu J, Wu B, Zhang M, Zhou W, Zhou Y, Jin H, Zhang Z, Qi C, Shen J, Mou S, Gu L, Ni Z. Drp1-regulated PARK2-dependent mitophagy protects against renal fibrosis in unilateral ureteral obstruction. Free Radic Biol Med 2020; 152:632-649. [PMID: 31825802 DOI: 10.1016/j.freeradbiomed.2019.12.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 11/22/2019] [Accepted: 12/05/2019] [Indexed: 12/19/2022]
Abstract
Mitophagy is a principle mechanism to degrade damaged mitochondria through PARK2-dependent or PARK2-independent pathway. Mitophagy has been identified to play an important role in acute kidney disease, whereas its role in renal fibrosis remains ill-defined. We sought to investigate the involvement and regulation of mitophagy in renal tubular epithelial cell(RTEC) injury and renal fibrosis after unilateral ureteral obstruction(UUO). Mitochondrial damageand mitochondrial reactive oxygen species (ROS) production was increased in kidney after obstruction of the left ureter. Mitophagy was increased in kidneys following UUO and HK-2 cells under hypoxia exposure, assessed by electron microscopy of mitophagosome, colocalization of MitotrackerRed-stained mitochondria and LC3 staining. The upregulation of PINK1, PARK2, and LC3 II in mitochondrial fraction was observed in the obstructed kidney and hypoxia-exposed HK-2 cells. Pink1 or Park2 gene deletion markedly increased mtROS production, mitochondrial damage, TGFβ1 expression in RTEC, and renal fibrosis in UUO. Mitochondrial recruitment of Drp1 was also induced after UUO. The Drp1 inhibitor, Mdivi-1, decreased mitochondrial PINK1, PARK2 and LC3II level, increased mtROS production both in vivo and in vitro, activated TGFβ1-Smad2/3 signaling in HK-2 cells under hypoxia and worsened renal fibrosis following UUO. The upregulation of TGFβ1 signaling in hypoxia-treated HK-2 cells due to PINK1 or PARK2 silencing, or worsened renal fibrosis after UUO due to Pink1-or Park2-KO mice was rescued by mitoTEMPO, a mitochondria-targeted antioxidant. The findings of this study suggest that Drp1-regulated PARK2-dependent mitophagy plays a critical role in hypoxia-induced renal tubular epithelial cell injury and renal fibrosis in UUO.
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Affiliation(s)
- Shu Li
- Department of Nephrology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Qisheng Lin
- Department of Nephrology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Xinghua Shao
- Department of Nephrology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Xuying Zhu
- Department of Nephrology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Jingkui Wu
- Department of Nephrology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Bei Wu
- Department of Nephrology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Minfang Zhang
- Department of Nephrology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Wenyan Zhou
- Department of Nephrology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Yijun Zhou
- Department of Nephrology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Haijiao Jin
- Department of Nephrology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Zhen Zhang
- Department of Nephrology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Chaojun Qi
- Department of Nephrology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Jianxiao Shen
- Department of Nephrology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Shan Mou
- Department of Nephrology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Leyi Gu
- Department of Nephrology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Zhaohui Ni
- Department of Nephrology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China.
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22
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Polichnowski AJ, Griffin KA, Licea-Vargas H, Lan R, Picken MM, Long J, Williamson GA, Rosenberger C, Mathia S, Venkatachalam MA, Bidani AK. Pathophysiology of unilateral ischemia-reperfusion injury: importance of renal counterbalance and implications for the AKI-CKD transition. Am J Physiol Renal Physiol 2020; 318:F1086-F1099. [PMID: 32174143 DOI: 10.1152/ajprenal.00590.2019] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Unilateral ischemia-reperfusion (UIR) injury leads to progressive renal atrophy and tubulointerstitial fibrosis (TIF) and is commonly used to investigate the pathogenesis of the acute kidney injury-chronic kidney disease transition. Although it is well known that contralateral nephrectomy (CNX), even 2 wk post-UIR injury, can improve recovery, the physiological mechanisms and tubular signaling pathways mediating such improved recovery remain poorly defined. Here, we examined the renal hemodynamic and tubular signaling pathways associated with UIR injury and its reversal by CNX. Male Sprague-Dawley rats underwent left UIR or sham UIR and 2 wk later CNX or sham CNX. Blood pressure, left renal blood flow (RBF), and total glomerular filtration rate were assessed in conscious rats for 3 days before and over 2 wk after CNX or sham CNX. In the presence of a contralateral uninjured kidney, left RBF was lower (P < 0.05) from 2 to 4 wk following UIR (3.6 ± 0.3 mL/min) versus sham UIR (9.6 ± 0.3 mL/min). Without CNX, extensive renal atrophy, TIF, and tubule dedifferentiation, but minimal pimonidazole and hypoxia-inducible factor-1α positivity in tubules, were present at 4 wk post-UIR injury. Conversely, CNX led (P < 0.05) to sustained increases in left RBF (6.2 ± 0.6 mL/min) that preceded the increases in glomerular filtration rate. The CNX-induced improvement in renal function was associated with renal hypertrophy, more redifferentiated tubules, less TIF, and robust pimonidazole and hypoxia-inducible factor-1α staining in UIR injured kidneys. Thus, contrary to expectations, indexes of hypoxia are not observed with the extensive TIF at 4 wk post-UIR injury in the absence of CNX but are rather associated with the improved recovery of renal function and structure following CNX.
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Affiliation(s)
- Aaron J Polichnowski
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee.,Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee.,Renal Section, Department of Medicine, Edward Hines Jr. Veterans Administration Hospital, Hines, Illinois.,Division of Nephrology, Department of Medicine, Loyola University Medical Center, Maywood, Illinois
| | - Karen A Griffin
- Renal Section, Department of Medicine, Edward Hines Jr. Veterans Administration Hospital, Hines, Illinois.,Division of Nephrology, Department of Medicine, Loyola University Medical Center, Maywood, Illinois
| | - Hector Licea-Vargas
- Renal Section, Department of Medicine, Edward Hines Jr. Veterans Administration Hospital, Hines, Illinois.,Division of Nephrology, Department of Medicine, Loyola University Medical Center, Maywood, Illinois
| | - Rongpei Lan
- Department of Pathology, University of Texas Health Science Center, San Antonio, Texas
| | - Maria M Picken
- Department of Pathology, Loyola University Medical Center, Maywood, Illinois
| | - Jainrui Long
- Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, Illinois
| | - Geoffrey A Williamson
- Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, Illinois
| | - Christian Rosenberger
- Department of Nephrology and Medical Intensive Care, Charité Universitaetsmedizin, Berlin, Germany
| | - Susanne Mathia
- Department of Nephrology and Medical Intensive Care, Charité Universitaetsmedizin, Berlin, Germany
| | | | - Anil K Bidani
- Renal Section, Department of Medicine, Edward Hines Jr. Veterans Administration Hospital, Hines, Illinois.,Division of Nephrology, Department of Medicine, Loyola University Medical Center, Maywood, Illinois
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23
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Wang Y, Zhang X, Wang B, Xie Y, Wang Y, Jiang X, Wang R, Ren K. Evaluation of Renal Pathophysiological Processes Induced by an Iodinated Contrast Agent in a Diabetic Rabbit Model Using Intravoxel Incoherent Motion and Blood Oxygenation Level-Dependent Magnetic Resonance Imaging. Korean J Radiol 2020; 20:830-843. [PMID: 30993934 PMCID: PMC6470079 DOI: 10.3348/kjr.2018.0757] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 01/03/2019] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE To examine the potential of intravoxel incoherent motion (IVIM) and blood oxygen level-dependent (BOLD) magnetic resonance imaging for detecting renal changes after iodinated contrast-induced acute kidney injury (CI-AKI) development in a diabetic rabbit model. MATERIALS AND METHODS Sixty-two rabbits were randomized into 2 groups: diabetic rabbits with the contrast agent (DCA) and healthy rabbits with the contrast agent (NCA). In each group, 6 rabbits underwent IVIM and BOLD imaging at 1 hour, 1 day, 2 days, 3 days, and 4 days after an iohexol injection while 5 rabbits were selected to undergo blood and histological examinations at these specific time points. Iohexol was administrated at a dose of 2.5 g I/kg of body weight. Further, the apparent transverse relaxation rate (R2*), average pure molecular diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) were calculated. RESULTS The D and f values of the renal cortex (CO) and outer medulla (OM) were significantly decreased compared to baseline values in the 2 groups 1 day after the iohexol injection (p < 0.05). A marked reduction in the D* values for both the CO and OM was also observed after 1 hour in each group (p < 0.05). In the OM, a persistent elevation of the R2* was detected for 4 days in the DCA group (p < 0.05). Histopathological changes were prominent, and the pathological features of CI-AKI aggravated in the DCA group until day 4. The D, f, and R2* values significantly correlated with the histological damage scores, hypoxia-inducible transcription factor-1α expression scores, and serum creatinine levels. CONCLUSION A combination of IVIM and BOLD imaging may serve as a noninvasive method for detecting and monitoring CI-AKI in the early stages in the diabetic kidney.
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Affiliation(s)
- Yongfang Wang
- Department of Radiology, First Hospital of China Medical University, Shenyang, China
| | - Xin Zhang
- Department of Radiology, First Hospital of China Medical University, Shenyang, China
| | - Bin Wang
- Department of Radiology, First Hospital of Shanxi Medical University, Taiyuan, China
| | - Yang Xie
- Department of Radiology, First Hospital of China Medical University, Shenyang, China
| | - Yi Wang
- Department of Radiology, The Qianfoshan Hospital of Shandong Province, Jinan, China
| | - Xuan Jiang
- Cardiac Surgery, First Hospital of China Medical University, Shenyang, China
| | - Rongjia Wang
- Department of Radiology, First Hospital of China Medical University, Shenyang, China
| | - Ke Ren
- Department of Radiology, First Hospital of China Medical University, Shenyang, China.
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Aubert V, Kaminski J, Guillaud F, Hauet T, Hannaert P. A Computer Model of Oxygen Dynamics in the Cortex of the Rat Kidney at the Cell-Tissue Level. Int J Mol Sci 2019; 20:E6246. [PMID: 31835730 PMCID: PMC6941061 DOI: 10.3390/ijms20246246] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 12/02/2019] [Accepted: 12/05/2019] [Indexed: 02/06/2023] Open
Abstract
The renal cortex drives renal function. Hypoxia/reoxygenation are primary factors in ischemia-reperfusion (IR) injuries, but renal oxygenation per se is complex and awaits full elucidation. Few mathematical models address this issue: none captures cortical tissue heterogeneity. Using agent-based modeling, we develop the first model of cortical oxygenation at the cell-tissue level (RCM), based on first principles and careful bibliographical analysis. Entirely parameterized with Rat data, RCM is a morphometrically equivalent 2D-slice of cortical tissue, featuring peritubular capillaries (PTC), tubules and interstitium. It implements hemoglobin/O2 binding-release, oxygen diffusion, and consumption, as well as capillary and tubular flows. Inputs are renal blood flow RBF and PO2 feeds; output is average tissue PO2 (tPO2). After verification and sensitivity analysis, RCM was validated at steady-state (tPO2 37.7 ± 2.2 vs. 36.9 ± 6 mmHg) and under transients (ischemic oxygen half-time: 4.5 ± 2.5 vs. 2.3 ± 0.5 s in situ). Simulations confirm that PO2 is largely independent of RBF, except at low values. They suggest that, at least in the proximal tubule, the luminal flow dominantly contributes to oxygen delivery, while the contribution of capillaries increases under partial ischemia. Before addressing IR-induced injuries, upcoming developments include ATP production, adaptation to minutes-hours scale, and segmental and regional specification.
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Affiliation(s)
| | | | | | | | - Patrick Hannaert
- INSERM U1082-IRTOMIT, 86000 Poitiers, France; (V.A.); (J.K.); (F.G.); (T.H.)
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25
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Qiu Y, Huang X, He W. The regulatory role of HIF-1 in tubular epithelial cells in response to kidney injury. Histol Histopathol 2019; 35:321-330. [PMID: 31691948 DOI: 10.14670/hh-18-182] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The high sensitivity to changes in oxygen tension makes kidney vulnerable to hypoxia. Both acute kidney injury and chronic kidney disease are almost always accompanied by hypoxia. Tubular epithelial cells (TECs), the dominant intrinsic cells in kidney tissue, are believed to be not only a victim in the pathological process of various kidney diseases, but also a major contributor to kidney damage. Hypoxia inducible factor-1 (HIF-1) is the main regulator of adaptive response of cells to hypoxia. Under various clinical and experimental kidney disease conditions, HIF-1 plays a pivotal role in modulating multiple cellular processes in TECs, including apoptosis, autophagy, inflammation, metabolic pattern alteration, and cell cycle arrest. A comprehensive understanding of the mechanisms by which HIF-1 regulates these cellular processes in TECs may help identify potential therapeutic targets to improve the outcome of acute kidney injury and delay the progression of chronic kidney disease.
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Affiliation(s)
- Yumei Qiu
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xiaowen Huang
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Weichun He
- Center for Kidney Disease, Second Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China.
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26
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Maekawa H, Inagi R. Pathophysiological Role of Organelle Stress/Crosstalk in AKI-to-CKD Transition. Semin Nephrol 2019; 39:581-588. [DOI: 10.1016/j.semnephrol.2019.10.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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27
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Romão CM, Pereira RC, Shimizu MHM, Furukawa LNS. N-acetyl-l-cysteine exacerbates kidney dysfunction caused by a chronic high-sodium diet in renal ischemia and reperfusion rats. Life Sci 2019; 231:116544. [PMID: 31181229 DOI: 10.1016/j.lfs.2019.116544] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 06/03/2019] [Accepted: 06/05/2019] [Indexed: 01/01/2023]
Abstract
AIMS To investigate the effect of long-term N-acetyl-l-cysteine (NAC) treatment in Wistar rats subjected to renal ischemia and reperfusion (IR) and a chronic high‑sodium diet (HSD). MAIN METHODS Adult male Wistar rats received an HSD (8.0% NaCl) or a normal‑sodium diet (NSD; 1.3% NaCl) and NAC (600 mg/L) or normal drinking water starting at 8 weeks of age. At 11 weeks of age, the rats from both diet and NAC or water treatment groups underwent renal IR or Sham surgery and were followed for 10 weeks. The study consisted of six animal groups: NSD + Sham + water; NSD + IR + water; NSD + IR + NAC; HSD + Sham + water; HSD + IR + water; and HSD + IR + NAC. KEY FINDINGS Tail blood pressure (tBP) increased with IR and NAC treatment in the NSD group but not in the HSD group. The serum creatinine level was higher after NAC treatment in both diet groups, and creatinine clearance was decreased in only the HSD + IR + NAC group. Albuminuria increased in the HSD + IR + water group and decreased in the HSD + IR + NAC group. Kidney mass was increased in the HSD + IR group and decreased with NAC treatment. Renal fibrosis was prevented with NAC treatment and cardiac fibrosis was decreased with NAC treatment in the HSD + IR group. SIGNIFICANCE NAC treatment promoted structural improvements, such as decreased albuminuria and fibrosis, in the kidney and heart. However, NAC could not recover kidney function or blood pressure from the effects of IR associated with an HSD. Therefore, in general, long-term NAC treatment is not effective and is deleterious to recovery of function after kidney injury.
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Affiliation(s)
- Carolina Martinez Romão
- Laboratory of Renal Pathophysiology, Department of Internal Medicine, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Rafael Canavel Pereira
- Laboratory of Renal Pathophysiology, Department of Internal Medicine, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Maria Heloisa Massola Shimizu
- Laboratory of Renal Pathophysiology, Department of Internal Medicine, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Luzia Naôko Shinohara Furukawa
- Laboratory of Renal Pathophysiology, Department of Internal Medicine, School of Medicine, University of São Paulo, São Paulo, Brazil.
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28
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Ow CPC, Ullah MM, Ngo JP, Sayakkarage A, Evans RG. Detection of cellular hypoxia by pimonidazole adduct immunohistochemistry in kidney disease: methodological pitfalls and their solution. Am J Physiol Renal Physiol 2019; 317:F322-F332. [PMID: 31188031 DOI: 10.1152/ajprenal.00219.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Pimonidazole adduct immunohistochemistry is one of the few available methods for assessing renal tissue hypoxia at the cellular level. It appears to be prone to artifactual false positive staining under some circumstances. Here, we assessed the nature of this false positive staining and, having determined how to avoid it, reexamined the nature of cellular hypoxia in rat models of kidney disease. When a mouse-derived anti-pimonidazole primary antibody was used, two types of staining were observed. First, there was diffuse staining of the cytoplasm of tubular epithelial cells, which was largely absent when the primary antibody was omitted from the incubation protocol or in tissues known not to contain pimonidazole adducts. Second, there was staining of the apical membranes of tubular epithelial cells, debris within the lumen of renal tubules, including tubular casts, and the interstitium; this latter staining was present even when the primary antibody was omitted from the incubation protocol. Such false positive staining was particularly prominent in acutely injured kidneys. It could not be avoided by preincubation of sections with a mouse IgG blocking reagent. Furthermore, preadsorption of the secondary antibody against rat Ig abolished all staining; however, when a rabbit-derived polyclonal anti-pimonidazole primary antibody was used, the false positive staining was largely avoided. Using this method, we confirmed the presence of hypoxia, localized mainly to the tubular epithelium, in the acute phase of severe renal ischemia-reperfusion injury, adenine-induced chronic kidney disease, and polycystic kidney disease. We conclude that this new method provides improved detection of renal cellular hypoxia.
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Affiliation(s)
- Connie P C Ow
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology, Monash University , Melbourne, Victoria , Australia
| | - Md Mahbub Ullah
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology, Monash University , Melbourne, Victoria , Australia
| | - Jennifer P Ngo
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology, Monash University , Melbourne, Victoria , Australia
| | - Adheeshee Sayakkarage
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology, Monash University , Melbourne, Victoria , Australia
| | - Roger G Evans
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology, Monash University , Melbourne, Victoria , Australia
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29
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Situmorang GR, Sheerin NS. Ischaemia reperfusion injury: mechanisms of progression to chronic graft dysfunction. Pediatr Nephrol 2019; 34:951-963. [PMID: 29603016 PMCID: PMC6477994 DOI: 10.1007/s00467-018-3940-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 02/18/2018] [Accepted: 03/02/2018] [Indexed: 12/18/2022]
Abstract
The increasing use of extended criteria organs to meet the demand for kidney transplantation raises an important question of how the severity of early ischaemic injury influences long-term outcomes. Significant acute ischaemic kidney injury is associated with delayed graft function, increased immune-associated events and, ultimately, earlier deterioration of graft function. A comprehensive understanding of immediate molecular events that ensue post-ischaemia and their potential long-term consequences are key to the discovery of novel therapeutic targets. Acute ischaemic injury primarily affects tubular structure and function. Depending on the severity and persistence of the insult, this may resolve completely, leading to restoration of normal function, or be sustained, resulting in persistent renal impairment and progressive functional loss. Long-term effects of acute renal ischaemia are mediated by several mechanisms including hypoxia, HIF-1 activation, endothelial dysfunction leading to vascular rarefaction, sustained pro-inflammatory stimuli involving innate and adaptive immune responses, failure of tubular cells to recover and epigenetic changes. This review describes the biological relevance and interaction of these mechanisms based on currently available evidence.
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Affiliation(s)
- Gerhard R Situmorang
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
- Urology Department, Faculty of Medicine Universitas Indonesia - Cipto Mangunkusumo Hospital, Jakarta, 10430, Indonesia
| | - Neil S Sheerin
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
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30
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Hypoxia and Hypoxia-Inducible Factors in Kidney Injury and Repair. Cells 2019; 8:cells8030207. [PMID: 30823476 PMCID: PMC6468851 DOI: 10.3390/cells8030207] [Citation(s) in RCA: 162] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 02/21/2019] [Accepted: 02/25/2019] [Indexed: 02/07/2023] Open
Abstract
Acute kidney injury (AKI) is a major kidney disease characterized by an abrupt loss of renal function. Accumulating evidence indicates that incomplete or maladaptive repair after AKI can result in kidney fibrosis and the development and progression of chronic kidney disease (CKD). Hypoxia, a condition of insufficient supply of oxygen to cells and tissues, occurs in both acute and chronic kidney diseases under a variety of clinical and experimental conditions. Hypoxia-inducible factors (HIFs) are the "master" transcription factors responsible for gene expression in hypoxia. Recent researches demonstrate that HIFs play an important role in kidney injury and repair by regulating HIF target genes, including microRNAs. However, there are controversies regarding the pathological roles of HIFs in kidney injury and repair. In this review, we describe the regulation, expression, and functions of HIFs, and their target genes and related functions. We also discuss the involvement of HIFs in AKI and kidney repair, presenting HIFs as effective therapeutic targets.
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31
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Sigurjonsdottir VK, Chaturvedi S, Mammen C, Sutherland SM. Pediatric acute kidney injury and the subsequent risk for chronic kidney disease: is there cause for alarm? Pediatr Nephrol 2018; 33:2047-2055. [PMID: 29374316 DOI: 10.1007/s00467-017-3870-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 12/03/2017] [Accepted: 12/04/2017] [Indexed: 02/02/2023]
Abstract
Acute kidney injury (AKI) is characterized clinically as an abrupt decline in renal function marked by reduced excretion of waste products, disordered electrolytes, and disrupted fluid homeostasis. The recent development of a standardized AKI definition has transformed our understanding of AKI epidemiology and outcomes. We now know that in the short term, children with AKI experience greater morbidity and mortality; additionally, observational studies have established that chronic renal sequelae are far more common after AKI events than previously realized. Many of these studies suggest that patients who develop AKI are at greater risk for the subsequent development of chronic kidney disease (CKD). The goal of this review is to critically evaluate the data regarding the association between AKI and CKD in children. Additionally, we describe best practice approaches for future studies, including the use of consensus AKI criteria, the application of rigorous definitions for CKD and renal sequelae, and the inclusion of non-AKI comparator groups. Finally, based upon existing data, we suggest an archetypal approach to follow-up care for the AKI survivors who may be at greater CKD risk, including children with more severe AKI, those who endure repeated AKI episodes, patients who do not experience full recovery, and those with pre-existing CKD.
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Affiliation(s)
- Vaka K Sigurjonsdottir
- Department of Pediatrics, Division of Nephrology, Stanford University School of Medicine, 300 Pasteur Drive, Room G-306, Stanford, CA, USA
| | | | - Cherry Mammen
- Division of Paediatric Nephrology, Department of Paediatrics, British Columbia Children's Hospital, Vancouver, BC, Canada
| | - Scott M Sutherland
- Department of Pediatrics, Division of Nephrology, Stanford University School of Medicine, 300 Pasteur Drive, Room G-306, Stanford, CA, USA.
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32
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Polichnowski AJ. Microvascular rarefaction and hypertension in the impaired recovery and progression of kidney disease following AKI in preexisting CKD states. Am J Physiol Renal Physiol 2018; 315:F1513-F1518. [PMID: 30256130 DOI: 10.1152/ajprenal.00419.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Acute kidney injury (AKI) is a major complication in hospitalized patients and is associated with elevated mortality rates. Numerous recent studies indicate that AKI also significantly increases the risk of chronic kidney disease (CKD), end-stage renal disease (ESRD), hypertension, cardiovascular disease, and mortality in those patients who survive AKI. Moreover, the risk of ESRD and mortality after AKI is substantially higher in patients with preexisting CKD. However, the underlying mechanisms by which AKI and CKD interact to promote ESRD remain poorly understood. The recently developed models that superimpose AKI on rodents with preexisting CKD have provided new insights into the pathogenic mechanisms mediating the deleterious interactions between AKI and CKD. These studies show that preexisting CKD impairs recovery from AKI and promotes the development of mechanisms of CKD progression. Specifically, preexisting CKD exacerbates microvascular rarefaction, failed tubular redifferentiation, disruption of cell cycle regulation, hypertension, and proteinuria after AKI. The purpose of this review is to discuss the potential mechanisms by which microvascular rarefaction and hypertension contribute to impaired recovery from AKI and the subsequent progression of renal disease in preexisting CKD states.
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Affiliation(s)
- Aaron J Polichnowski
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee.,Center of Excellence in Inflammation, Infectious Disease and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
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33
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Ow CPC, Ngo JP, Ullah MM, Barsha G, Meex RC, Watt MJ, Hilliard LM, Koeners MP, Evans RG. Absence of renal hypoxia in the subacute phase of severe renal ischemia-reperfusion injury. Am J Physiol Renal Physiol 2018; 315:F1358-F1369. [PMID: 30110566 PMCID: PMC6293301 DOI: 10.1152/ajprenal.00249.2018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Tissue hypoxia has been proposed as an important event in renal ischemia-reperfusion injury (IRI), particularly during the period of ischemia and in the immediate hours following reperfusion. However, little is known about renal oxygenation during the subacute phase of IRI. We employed four different methods to assess the temporal and spatial changes in tissue oxygenation during the subacute phase (24 h and 5 days after reperfusion) of a severe form of renal IRI in rats. We hypothesized that the kidney is hypoxic 24 h and 5 days after an hour of bilateral renal ischemia, driven by a disturbed balance between renal oxygen delivery (Do2) and oxygen consumption (V̇o2). Renal Do2 was not significantly reduced in the subacute phase of IRI. In contrast, renal V̇o2 was 55% less 24 h after reperfusion and 49% less 5 days after reperfusion than after sham ischemia. Inner medullary tissue Po2, measured by radiotelemetry, was 25 ± 12% (mean ± SE) greater 24 h after ischemia than after sham ischemia. By 5 days after reperfusion, tissue Po2 was similar to that in rats subjected to sham ischemia. Tissue Po2 measured by Clark electrode was consistently greater 24 h, but not 5 days, after ischemia than after sham ischemia. Cellular hypoxia, assessed by pimonidazole adduct immunohistochemistry, was largely absent at both time points, and tissue levels of hypoxia-inducible factors were downregulated following renal ischemia. Thus, in this model of severe IRI, tissue hypoxia does not appear to be an obligatory event during the subacute phase, likely because of the markedly reduced oxygen consumption.
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Affiliation(s)
- Connie P C Ow
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Physiology, Monash University , Melbourne, Victoria , Australia
| | - Jennifer P Ngo
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Physiology, Monash University , Melbourne, Victoria , Australia
| | - Md Mahbub Ullah
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Physiology, Monash University , Melbourne, Victoria , Australia
| | - Giannie Barsha
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Physiology, Monash University , Melbourne, Victoria , Australia
| | - Ruth C Meex
- Department of Human Biology, NUTRIM School of Nutritional and Translational Research in Metabolism, Maastricht University Medical Centre , Maastricht , The Netherlands
| | - Matthew J Watt
- Metabolism, Diabetes and Obesity Program, Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, Victoria, Australia
| | - Lucinda M Hilliard
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Physiology, Monash University , Melbourne, Victoria , Australia
| | - Maarten P Koeners
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences, University of Bristol , Bristol , United Kingdom.,Institute of Biomedical and Clinical Science, University of Exeter Medical School , Exeter , United Kingdom
| | - Roger G Evans
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Physiology, Monash University , Melbourne, Victoria , Australia
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Yang B, Lan S, Dieudé M, Sabo-Vatasescu JP, Karakeussian-Rimbaud A, Turgeon J, Qi S, Gunaratnam L, Patey N, Hébert MJ. Caspase-3 Is a Pivotal Regulator of Microvascular Rarefaction and Renal Fibrosis after Ischemia-Reperfusion Injury. J Am Soc Nephrol 2018; 29:1900-1916. [PMID: 29925521 DOI: 10.1681/asn.2017050581] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 05/11/2018] [Indexed: 12/31/2022] Open
Abstract
Background Ischemia-reperfusion injury (IRI) is a major risk factor for chronic renal failure. Here, we characterize the different modes of programmed cell death in the tubular and microvascular compartments during the various stages of IRI-induced AKI, and their relative importance to renal fibrogenesis.Methods We performed unilateral renal artery clamping for 30 minutes and contralateral nephrectomy in wild-type mice (C57BL/6) or caspase-3-/- mice.Results Compared with their wild-type counterparts, caspase-3-/- mice in the early stage of AKI had high urine cystatin C levels, tubular injury scores, and serum creatinine levels. Electron microscopy revealed evidence of tubular epithelial cell necrosis in caspase-3-/- mice, and immunohistochemistry showed upregulation of the necroptosis marker receptor-interacting serine/threonine-protein kinase 3 (RIPK3) in renal cortical sections. Western blot analysis further demonstrated enhanced levels of phosphorylated RIPK3 in the kidneys of caspase-3-/- mice. In contrast, caspase-3-/- mice had less microvascular congestion and activation in the early and extension phases of AKI. In the long term (3 weeks after IRI), caspase-3-/- mice had reduced microvascular rarefaction and renal fibrosis, as well as decreased expression of α-smooth muscle actin and reduced collagen deposition within peritubular capillaries. Moreover, caspase-3-/- mice exhibited signs of reduced tubular ischemia, including lower tubular expression of hypoxia-inducible factor-1α and improved tubular injury scores.Conclusions These results establish the pivotal importance of caspase-3 in regulating microvascular endothelial cell apoptosis and renal fibrosis after IRI. These findings also demonstrate the predominant role of microvascular over tubular injury as a driver of progressive renal damage and fibrosis after IRI.
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Affiliation(s)
- Bing Yang
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada.,Canadian National Transplant Research Program, Edmonton, Alberta, Canada.,Université de Montréal, Montreal, Quebec, Canada
| | - Shanshan Lan
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada.,Canadian National Transplant Research Program, Edmonton, Alberta, Canada.,Université de Montréal, Montreal, Quebec, Canada
| | - Mélanie Dieudé
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada.,Canadian National Transplant Research Program, Edmonton, Alberta, Canada.,Université de Montréal, Montreal, Quebec, Canada
| | | | - Annie Karakeussian-Rimbaud
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada.,Canadian National Transplant Research Program, Edmonton, Alberta, Canada
| | - Julie Turgeon
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada.,Canadian National Transplant Research Program, Edmonton, Alberta, Canada
| | - Shijie Qi
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada.,Canadian National Transplant Research Program, Edmonton, Alberta, Canada
| | - Lakshman Gunaratnam
- Canadian National Transplant Research Program, Edmonton, Alberta, Canada.,London Health Sciences Centre, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada; and
| | - Natalie Patey
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada; .,Canadian National Transplant Research Program, Edmonton, Alberta, Canada.,Université de Montréal, Montreal, Quebec, Canada.,Department of Pathology, Centre hospitalier universitaire Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada
| | - Marie-Josée Hébert
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, Quebec, Canada; .,Canadian National Transplant Research Program, Edmonton, Alberta, Canada.,Université de Montréal, Montreal, Quebec, Canada
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35
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Cardinal H, Dieudé M, Hébert MJ. Endothelial Dysfunction in Kidney Transplantation. Front Immunol 2018; 9:1130. [PMID: 29875776 PMCID: PMC5974048 DOI: 10.3389/fimmu.2018.01130] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 05/04/2018] [Indexed: 12/17/2022] Open
Abstract
Kidney transplantation entails a high likelihood of endothelial injury. The endothelium is a target of choice for injury by ischemia-reperfusion, alloantibodies, and autoantibodies. A certain degree of ischemia-reperfusion injury inevitably occurs in the immediate posttransplant setting and can manifest as delayed graft function. Acute rejection episodes, whether T-cell or antibody-mediated, can involve the graft micro- and macrovasculature, leading to endothelial injury and adverse long-term consequences on graft function and survival. In turn, caspase-3 activation in injured and dying endothelial cells favors the release of extracellular vesicles (apoptotic bodies and apoptotic exosome-like vesicles) that further enhance autoantibody production, complement deposition, and microvascular rarefaction. In this review, we present the evidence for endothelial injury, its causes and long-term consequences on graft outcomes in the field of kidney transplantation.
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Affiliation(s)
- Héloïse Cardinal
- Research Centre, Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada.,Canadian National Transplant Research Program, Montreal, QC, Canada.,University of Montreal, Montreal, QC, Canada
| | - Mélanie Dieudé
- Research Centre, Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada.,Canadian National Transplant Research Program, Montreal, QC, Canada
| | - Marie-Josée Hébert
- Research Centre, Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada.,Canadian National Transplant Research Program, Montreal, QC, Canada.,University of Montreal, Montreal, QC, Canada
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36
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Abstract
Tubulointerstitial fibrosis is a chronic and progressive process affecting kidneys during aging and in chronic kidney disease (CKD), regardless of cause. CKD and renal fibrosis affect half of adults above age 70 and 10% of the world's population. Although no targeted therapy yet exists to slow renal fibrosis, a number of important recent advances have clarified the cellular and molecular mechanisms underlying the disease. In this review, I highlight these advances with a focus on cells and pathways that may be amenable to therapeutic targeting. I discuss pathologic changes regulating interstitial myofibroblast activation, including profibrotic and proinflammatory paracrine signals secreted by epithelial cells after either acute or chronic injury. I conclude by highlighting novel therapeutic targets and approaches with particular promise for development of new treatments for patients with fibrotic kidney disease.
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Affiliation(s)
- Benjamin D Humphreys
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA;
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37
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Li L, Zviti R, Ha C, Wang ZV, Hill JA, Lin F. Forkhead box O3 (FoxO3) regulates kidney tubular autophagy following urinary tract obstruction. J Biol Chem 2017; 292:13774-13783. [PMID: 28705935 DOI: 10.1074/jbc.m117.791483] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 07/11/2017] [Indexed: 12/20/2022] Open
Abstract
Autophagy has been shown to be important for normal homeostasis and adaptation to stress in the kidney. Yet, the molecular mechanisms regulating renal epithelial autophagy are not fully understood. Here, we explored the role of the stress-responsive transcription factor forkhead box O3 (FoxO3) in mediating injury-induced proximal tubular autophagy in mice with unilateral ureteral obstruction (UUO). We show that following UUO, FoxO3 is activated and displays nuclear expression in the hypoxic proximal tubules exhibiting high levels of autophagy. Activation of FoxO3 by mutating phosphorylation sites to enhance its nuclear expression induces profound autophagy in cultured renal epithelial cells. Conversely, deleting FoxO3 in mice results in fewer numbers of autophagic cells in the proximal tubules and reduced ratio of the autophagy-related protein LC3-II/I in the kidney post-UUO. Interestingly, autophagic cells deficient in FoxO3 contain lower numbers of autophagic vesicles per cell. Analyses of individual cells treated with autophagic inhibitors to sequentially block the autophagic flux suggest that FoxO3 stimulates the formation of autophagosomes to increase autophagic capacity but has no significant effect on autophagosome-lysosome fusion or autolysosomal clearance. Furthermore, in kidneys with persistent UUO for 7 days, FoxO3 activation increases the abundance of mRNA and protein levels of the core autophagy-related (Atg) proteins including Ulk1, Beclin-1, Atg9A, Atg4B, and Bnip3, suggesting that FoxO3 may function to maintain components of the autophagic machinery that would otherwise be consumed during prolonged autophagy. Taken together, our findings indicate that FoxO3 activation can both induce and maintain autophagic activities in renal epithelial cells in response to injury from urinary tract obstruction.
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Affiliation(s)
- Ling Li
- From the Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York 10032 and
| | - Ronald Zviti
- From the Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York 10032 and
| | - Catherine Ha
- From the Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York 10032 and
| | - Zhao V Wang
- the Departments of Internal Medicine (Cardiology) and.,Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Joseph A Hill
- the Departments of Internal Medicine (Cardiology) and.,Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Fangming Lin
- From the Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York 10032 and
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38
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Harer MW, Pope CF, Conaway MR, Charlton JR. Follow-up of Acute kidney injury in Neonates during Childhood Years (FANCY): a prospective cohort study. Pediatr Nephrol 2017; 32:1067-1076. [PMID: 28255805 DOI: 10.1007/s00467-017-3603-x] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 12/17/2016] [Accepted: 12/19/2016] [Indexed: 12/22/2022]
Abstract
BACKGROUND Very low birth weight (VLBW) neonates commonly experience acute kidney injury (AKI) in the neonatal intensive care unit (NICU). We hypothesize that VLBW neonates exposed to AKI in the NICU might be at a higher risk of renal dysfunction during childhood. METHODS In this cohort study, VLBW children (aged 3-7 years) completed a kidney health evaluation and were stratified according to AKI status in the NICU. The primary outcome was renal dysfunction defined as any of the following: estimated glomerular filtration rate (eGFR) <90 mL/min/1.73 m2, urine protein/creatinine >0.2 or blood pressure ≥95th percentile. RESULTS Thirty-four subjects completed the study. Twenty subjects had a history of neonatal AKI (stage 1, n = 8; stage 2, n = 9; and stage 3, n = 3). At a median age of 5 years, the AKI group had a higher risk of renal dysfunction compared with the group without AKI (65% vs 14%, relative risk 4.5 (1.2-17.1), p = 0.01). Overall, 26% of the total cohort had an eGFR <90 mL/min/1.73 m2 using serum cystatin C (35% of AKI subjects, 14% of no AKI subjects, p = 0.25). CONCLUSIONS Evidence of renal dysfunction in neonates born VLBW can be found early in childhood. Further work is necessary to determine how to reduce renal disease in this vulnerable population.
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Affiliation(s)
- Matthew W Harer
- Division of Neonatology, Department of Pediatrics, University of Wisconsin-Madison, School of Medicine and Public Health, Madison, WI, USA
| | - Chelsea F Pope
- Division of Pediatrics, Department of Radiology, University of Virginia, Charlottesville, VA, USA
| | - Mark R Conaway
- Division of Translational Research and Applied Statistics, Department of Public Health Sciences, University of Virginia, Charlottesville, VA, USA
| | - Jennifer R Charlton
- Division of Nephrology, Department of Pediatrics, University of Virginia Children's Hospital, Box 800386, Charlottesville, VA, 22908, USA.
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39
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Collett JA, Traktuev DO, Mehrotra P, Crone A, Merfeld-Clauss S, March KL, Basile DP. Human adipose stromal cell therapy improves survival and reduces renal inflammation and capillary rarefaction in acute kidney injury. J Cell Mol Med 2017; 21:1420-1430. [PMID: 28455887 PMCID: PMC5487924 DOI: 10.1111/jcmm.13071] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 11/26/2016] [Indexed: 12/16/2022] Open
Abstract
Damage to endothelial cells contributes to acute kidney injury (AKI) by causing impaired perfusion, while the permanent loss of the capillary network following AKI has been suggested to promote chronic kidney disease. Therefore, strategies to protect renal vasculature may impact both short‐term recovery and long‐term functional preservation post‐AKI. Human adipose stromal cells (hASCs) possess pro‐angiogenic and anti‐inflammatory properties and therefore have been tested as a therapeutic agent to treat ischaemic conditions. This study evaluated hASC potential to facilitate recovery from AKI with specific attention to capillary preservation and inflammation. Male Sprague Dawley rats were subjected to bilateral ischaemia/reperfusion and allowed to recover for either two or seven days. At the time of reperfusion, hASCs or vehicle was injected into the suprarenal abdominal aorta. hASC‐treated rats had significantly greater survival compared to vehicle‐treated rats (88.7% versus 69.3%). hASC treatment showed hastened recovery as demonstrated by lower creatinine levels at 48 hrs, while tubular damage was significantly reduced at 48 hrs. hASC treatment resulted in a significant decrease in total T cell and Th17 cell infiltration into injured kidneys at 2 days post‐AKI, but an increase in accumulation of regulatory T cells. By day 7, hASC‐treated rats showed significantly attenuated capillary rarefaction in the cortex (15% versus 5%) and outer medulla (36% versus 18%) compared to vehicle‐treated rats as well as reduced accumulation of interstitial alpha‐smooth muscle actin‐positive myofibroblasts. These results suggest for the first time that hASCs improve recovery from I/R‐induced injury by mechanisms that contribute to decrease in inflammation and preservation of peritubular capillaries.
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Affiliation(s)
- Jason A Collett
- Department of Cellular and Integrative Physiology, Krannert Institute of Cardiology, Indiana University School of Medicine, Indiana Center for Vascular Biology and Medicine, Indianapolis, IN, USA
| | - Dmitry O Traktuev
- VA Center for Regenerative Medicine Indianapolis, Richard L. Roudebush VA Medical Center, Indianapolis, IN, USA.,Department of Medicine, Krannert Institute of Cardiology, Indiana University School of Medicine, Indiana Center for Vascular Biology and Medicine, Indianapolis, IN, USA
| | - Purvi Mehrotra
- Department of Cellular and Integrative Physiology, Krannert Institute of Cardiology, Indiana University School of Medicine, Indiana Center for Vascular Biology and Medicine, Indianapolis, IN, USA
| | - Allison Crone
- Department of Cellular and Integrative Physiology, Krannert Institute of Cardiology, Indiana University School of Medicine, Indiana Center for Vascular Biology and Medicine, Indianapolis, IN, USA
| | - Stephanie Merfeld-Clauss
- VA Center for Regenerative Medicine Indianapolis, Richard L. Roudebush VA Medical Center, Indianapolis, IN, USA.,Department of Medicine, Krannert Institute of Cardiology, Indiana University School of Medicine, Indiana Center for Vascular Biology and Medicine, Indianapolis, IN, USA
| | - Keith L March
- VA Center for Regenerative Medicine Indianapolis, Richard L. Roudebush VA Medical Center, Indianapolis, IN, USA.,Department of Medicine, Krannert Institute of Cardiology, Indiana University School of Medicine, Indiana Center for Vascular Biology and Medicine, Indianapolis, IN, USA
| | - David P Basile
- Department of Cellular and Integrative Physiology, Krannert Institute of Cardiology, Indiana University School of Medicine, Indiana Center for Vascular Biology and Medicine, Indianapolis, IN, USA
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40
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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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41
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Venkatachalam MA, Weinberg JM. Pericytes Preserve Capillary Integrity to Prevent Kidney Hypoxia. J Am Soc Nephrol 2016; 28:717-719. [PMID: 27979991 DOI: 10.1681/asn.2016111157] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
| | - Joel M Weinberg
- Department of Medicine, University of Michigan Medical Center, Ann Arbor, Michigan
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42
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Hu P, Liu SY, Zhang DD, Xu Y, Xia X. Urinary C-type natriuretic peptide excretion: a promising biomarker to detect underlying renal injury and remodeling both acutely and chronically. Biomark Med 2016; 10:999-1008. [PMID: 27586401 DOI: 10.2217/bmm-2016-0089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Acute kidney injury (AKI) refers to a sudden decline in renal function. A growing body of evidence demonstrates that AKI is a risk factor for the future development or accelerated progression of chronic kidney disease (CKD), whereas the actual distinction between AKI and CKD remains unknown. CNP is predominantly present in the kidney and possesses multiple renoprotective properties. Urinary CNP excretion tends to be high in AKI, whereas back to the baseline in CKD. The dynamic changes in urinary CNP excretion may help detect underlying renal injury and remodeling both acutely and chronically.
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Affiliation(s)
- Peng Hu
- Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei 230022, PR China
| | - Si Yan Liu
- Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei 230022, PR China
| | - Dong Dong Zhang
- Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei 230022, PR China
| | - Yao Xu
- Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei 230022, PR China
| | - Xun Xia
- Department of Pediatrics, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei 230022, PR China
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43
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Fong D, Ullah MM, Lal JG, Abdelkader A, Ow CP, Hilliard LM, Ricardo SD, Kelly DJ, Evans RG. Renal cellular hypoxia in adenine-induced chronic kidney disease. Clin Exp Pharmacol Physiol 2016; 43:896-905. [DOI: 10.1111/1440-1681.12621] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 05/30/2016] [Accepted: 07/02/2016] [Indexed: 01/20/2023]
Affiliation(s)
- Debra Fong
- Biomedicine Discovery Institute and Department of Physiology; Monash University; Clayton Melbourne Vic. Australia
| | - Md Mahbub Ullah
- Biomedicine Discovery Institute and Department of Physiology; Monash University; Clayton Melbourne Vic. Australia
| | - Jaswini G. Lal
- Biomedicine Discovery Institute and Department of Physiology; Monash University; Clayton Melbourne Vic. Australia
| | - Amany Abdelkader
- Biomedicine Discovery Institute and Department of Physiology; Monash University; Clayton Melbourne Vic. Australia
| | - Connie P.C. Ow
- Biomedicine Discovery Institute and Department of Physiology; Monash University; Clayton Melbourne Vic. Australia
| | - Lucinda M. Hilliard
- Biomedicine Discovery Institute and Department of Physiology; Monash University; Clayton Melbourne Vic. Australia
| | - Sharon D. Ricardo
- Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology; Monash University; Clayton Melbourne Vic. Australia
| | - Darren J. Kelly
- Department of Medicine; University of Melbourne; St Vincent's Hospital; Fitzroy Melbourne Vic. Australia
| | - Roger G. Evans
- Biomedicine Discovery Institute and Department of Physiology; Monash University; Clayton Melbourne Vic. Australia
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44
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Picken M, Long J, Williamson GA, Polichnowski AJ. Progression of Chronic Kidney Disease After Acute Kidney Injury: Role of Self-Perpetuating Versus Hemodynamic-Induced Fibrosis. Hypertension 2016; 68:921-8. [PMID: 27550923 DOI: 10.1161/hypertensionaha.116.07749] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Accepted: 07/22/2016] [Indexed: 12/20/2022]
Abstract
The relative contribution of self-perpetuating versus hemodynamic-induced fibrosis to the progression of chronic kidney disease (CKD) after acute kidney injury (AKI) is unclear. In the present study, male Sprague-Dawley rats underwent right uninephrectomy and were instrumented with a blood pressure radiotelemeter. Two weeks later, separate groups of rats were subjected to 40 minutes renal ischemia-reperfusion or sham surgery and followed up for 4 or 16 weeks to determine the extent to which glomerulosclerosis and tubulointerstitial fibrosis as a result of the AKI-CKD transition (ie, at 4 weeks post AKI) change over time during the progression of CKD (ie, at 16 weeks post AKI). On average, tubulointerstitial fibrosis was ≈3-fold lower (P<0.05), whereas glomerulosclerosis was ≈6-fold higher (P<0.05) at 16 versus 4 weeks post AKI. At 16 weeks post AKI, marked tubulointerstitial fibrosis was only observed in rats exhibiting marked glomerulosclerosis, proteinuria, and kidney hypertrophy consistent with a hemodynamic pathogenesis of renal injury. Moreover, quantitative analysis between blood pressure and renal injury revealed a clear and modest blood pressure threshold (average 16-week systolic blood pressure of ≈127 mm Hg) for the development of glomerulosclerosis. In summary, modest levels of blood pressure may be playing a substantial role in the progression of renal disease after AKI in settings of preexisting CKD associated with 50% loss of renal mass. In contrast, these data do not support a major role of self-perpetuating tubulointerstitial fibrosis in the progression CKD after AKI in such settings.
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Affiliation(s)
- Maria Picken
- From the Research and Development Service, Edward Hines Jr. VA Hospital, Hines, IL (A.J.P.); Department of Medicine, (A.J.P.) and Department of Pathology (M.P.), Loyola University-Chicago, Maywood, IL; and Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago (J.L., G.A.W.)
| | - Jianrui Long
- From the Research and Development Service, Edward Hines Jr. VA Hospital, Hines, IL (A.J.P.); Department of Medicine, (A.J.P.) and Department of Pathology (M.P.), Loyola University-Chicago, Maywood, IL; and Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago (J.L., G.A.W.)
| | - Geoffrey A Williamson
- From the Research and Development Service, Edward Hines Jr. VA Hospital, Hines, IL (A.J.P.); Department of Medicine, (A.J.P.) and Department of Pathology (M.P.), Loyola University-Chicago, Maywood, IL; and Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago (J.L., G.A.W.)
| | - Aaron J Polichnowski
- From the Research and Development Service, Edward Hines Jr. VA Hospital, Hines, IL (A.J.P.); Department of Medicine, (A.J.P.) and Department of Pathology (M.P.), Loyola University-Chicago, Maywood, IL; and Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago (J.L., G.A.W.).
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45
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Coca SG, Zabetian A, Ferket BS, Zhou J, Testani JM, Garg AX, Parikh CR. Evaluation of Short-Term Changes in Serum Creatinine Level as a Meaningful End Point in Randomized Clinical Trials. J Am Soc Nephrol 2016; 27:2529-42. [PMID: 26712525 PMCID: PMC4978048 DOI: 10.1681/asn.2015060642] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 11/03/2015] [Indexed: 01/10/2023] Open
Abstract
Observational studies have shown that acute change in kidney function (specifically, AKI) is a strong risk factor for poor outcomes. Thus, the outcome of acute change in serum creatinine level, regardless of underlying biology or etiology, is frequently used in clinical trials as both efficacy and safety end points. We performed a meta-analysis of clinical trials to quantify the relationship between positive or negative short-term effects of interventions on change in serum creatinine level and more meaningful clinical outcomes. After a thorough literature search, we included 14 randomized trials of interventions that altered risk for an acute increase in serum creatinine level and had reported between-group differences in CKD and/or mortality rate ≥3 months after randomization. Seven trials assessed interventions that, compared with placebo, increased risk of acute elevation in serum creatinine level (pooled relative risk, 1.52; 95% confidence interval, 1.22 to 1.89), and seven trials assessed interventions that, compared with placebo, reduced risk of acute elevation in serum creatinine level (pooled relative risk, 0.57; 95% confidence interval, 0.44 to 0.74). However, pooled risks for CKD and mortality associated with interventions did not differ from those with placebo in either group. In conclusion, several interventions that affect risk of acute, mild to moderate, often temporary elevation in serum creatinine level in placebo-controlled randomized trials showed no appreciable effect on CKD or mortality months later, raising questions about the value of using small to moderate changes in serum creatinine level as end points in clinical trials.
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Affiliation(s)
| | - Azadeh Zabetian
- Program of Applied Translational Research, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut; and
| | - Bart S Ferket
- Institute for Healthcare Delivery Science, Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Jing Zhou
- Institute for Healthcare Delivery Science, Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Jeffrey M Testani
- Program of Applied Translational Research, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut; and
| | - Amit X Garg
- Division of Nephrology, Department of Medicine, Western University, London, Ontario, Canada
| | - Chirag R Parikh
- Program of Applied Translational Research, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut; and
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46
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Dagher PC, Hato T, Mang HE, Plotkin Z, Richardson QV, Massad M, Mai E, Kuehl SE, Graham P, Kumar R, Sutton TA. Inhibition of Toll-Like Receptor 4 Signaling Mitigates Microvascular Loss but Not Fibrosis in a Model of Ischemic Acute Kidney Injury. Int J Mol Sci 2016; 17:ijms17050647. [PMID: 27136544 PMCID: PMC4881473 DOI: 10.3390/ijms17050647] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 04/19/2016] [Accepted: 04/25/2016] [Indexed: 01/22/2023] Open
Abstract
The development of chronic kidney disease (CKD) following an episode of acute kidney injury (AKI) is an increasingly recognized clinical problem. Inhibition of toll-like receptor 4 (TLR4) protects renal function in animal models of AKI and has become a viable therapeutic strategy in AKI. However, the impact of TLR4 inhibition on the chronic sequelae of AKI is unknown. Consequently, we examined the chronic effects of TLR4 inhibition in a model of ischemic AKI. Mice with a TLR4-deletion on a C57BL/6 background and wild-type (WT) background control mice (C57BL/6) were subjected to bilateral renal artery clamping for 19 min and reperfusion for up to 6 weeks. Despite the acute protective effect of TLR4 inhibition on renal function (serum creatinine 1.6 ± 0.4 mg/dL TLR4-deletion vs. 2.8 ± 0.3 mg/dL·WT) and rates of tubular apoptosis following ischemic AKI, we found no difference in neutrophil or macrophage infiltration. Furthermore, we observed significant protection from microvascular rarefaction at six weeks following injury with TLR4-deletion, but this did not alter development of fibrosis. In conclusion, we validate the acute protective effect of TLR4 signal inhibition in AKI but demonstrate that this protective effect does not mitigate the sequential fibrogenic response in this model of ischemic AKI.
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Affiliation(s)
- Pierre C Dagher
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | - Takashi Hato
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | - Henry E Mang
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | - Zoya Plotkin
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | - Quentin V Richardson
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | - Michael Massad
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | - Erik Mai
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | - Sarah E Kuehl
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | - Paige Graham
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | - Rakesh Kumar
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | - Timothy A Sutton
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, R2-202, 950 West Walnut Street, Indianapolis, IN 46202, USA.
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47
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Lan R, Geng H, Singha PK, Saikumar P, Bottinger EP, Weinberg JM, Venkatachalam MA. Mitochondrial Pathology and Glycolytic Shift during Proximal Tubule Atrophy after Ischemic AKI. J Am Soc Nephrol 2016; 27:3356-3367. [PMID: 27000065 DOI: 10.1681/asn.2015020177] [Citation(s) in RCA: 211] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 02/03/2016] [Indexed: 02/01/2023] Open
Abstract
During recovery by regeneration after AKI, proximal tubule cells can fail to redifferentiate, undergo premature growth arrest, and become atrophic. The atrophic tubules display pathologically persistent signaling increases that trigger production of profibrotic peptides, proliferation of interstitial fibroblasts, and fibrosis. We studied proximal tubules after ischemia-reperfusion injury (IRI) to characterize possible mitochondrial pathologies and alterations of critical enzymes that govern energy metabolism. In rat kidneys, tubules undergoing atrophy late after IRI but not normally recovering tubules showed greatly reduced mitochondrial number, with rounded profiles, and large autophagolysosomes. Studies after IRI of kidneys in mice, done in parallel, showed large scale loss of the oxidant-sensitive mitochondrial protein Mpv17L. Renal expression of hypoxia markers also increased after IRI. During early and late reperfusion after IRI, kidneys exhibited increased lactate and pyruvate content and hexokinase activity, which are indicators of glycolysis. Furthermore, normally regenerating tubules as well as tubules undergoing atrophy exhibited increased glycolytic enzyme expression and inhibitory phosphorylation of pyruvate dehydrogenase. TGF-β antagonism prevented these effects. Our data show that the metabolic switch occurred early during regeneration after injury and was reversed during normal tubule recovery but persisted and became progressively more severe in tubule cells that failed to redifferentiate. In conclusion, irreversibility of the metabolic switch, taking place in the context of hypoxia, high TGF-β signaling and depletion of mitochondria characterizes the development of atrophy in proximal tubule cells and may contribute to the renal pathology after AKI.
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Affiliation(s)
- Rongpei Lan
- Department of Pathology, University of Texas Health Science Center, San Antonio, Texas
| | - Hui Geng
- Department of Pathology, University of Texas Health Science Center, San Antonio, Texas
| | - Prajjal K Singha
- Department of Pathology, University of Texas Health Science Center, San Antonio, Texas
| | - Pothana Saikumar
- Department of Pathology, University of Texas Health Science Center, San Antonio, Texas
| | - Erwin P Bottinger
- Department of Medicine, Mount Sinai School of Medicine, New York, New York; and
| | - Joel M Weinberg
- Department of Medicine, Veterans Affairs Ann Arbor Healthcare System and University of Michigan Medical Center, Ann Arbor, Michigan
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48
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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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Basile DP, Bonventre JV, Mehta R, Nangaku M, Unwin R, Rosner MH, Kellum JA, Ronco C. Progression after AKI: Understanding Maladaptive Repair Processes to Predict and Identify Therapeutic Treatments. J Am Soc Nephrol 2016; 27:687-97. [PMID: 26519085 PMCID: PMC4769207 DOI: 10.1681/asn.2015030309] [Citation(s) in RCA: 312] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Recent clinical studies indicate a strong link between AKI and progression of CKD. The increasing prevalence of AKI must compel the nephrology community to consider the long-term ramifications of this syndrome. Considerable gaps in knowledge exist regarding the connection between AKI and CKD. The 13th Acute Dialysis Quality Initiative meeting entitled "Therapeutic Targets of Human Acute Kidney Injury: Harmonizing Human and Experimental Animal Acute Kidney Injury" convened in April of 2014 and assigned a working group to focus on issues related to progression after AKI. This article provides a summary of the key conclusions and recommendations of the group, including an emphasis on terminology related to injury and repair processes for both clinical and preclinical studies, elucidation of pathophysiologic alterations of AKI, identification of potential treatment strategies, identification of patients predisposed to progression, and potential management strategies.
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Affiliation(s)
- David P Basile
- Department of Cellular and Integrative Physiology and Department of Medicine, Division of Nephrology, Indiana University, Indianapolis, Indiana;
| | - Joseph V Bonventre
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ravindra Mehta
- Division of Nephrology and Hypertension, Department of Medicine, University of California, San Diego, California
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Robert Unwin
- Division of Medicine, University College London Centre for Nephrology, University College London, London, United Kingdom
| | - Mitchell H Rosner
- Department of Medicine, Nephrology Division and the Centre for Immunity, Inflammation and Regenerative Medicine, University of Virginia, Charlottesville, Virginia
| | - John A Kellum
- Center for Critical Care Nephrology, The Clinical Research, Investigation, and Systems Modeling of Acute Illness Centre, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and
| | - Claudio Ronco
- Department of Nephrology Dialysis and Transplantation, San Bortolo Hospital and the International Renal Research Institute, Vicenza, Italy
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Mehrotra P, Patel JB, Ivancic CM, Collett JA, Basile DP. Th-17 cell activation in response to high salt following acute kidney injury is associated with progressive fibrosis and attenuated by AT-1R antagonism. Kidney Int 2015; 88:776-84. [PMID: 26200947 PMCID: PMC4589446 DOI: 10.1038/ki.2015.200] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 04/14/2015] [Accepted: 05/07/2015] [Indexed: 12/22/2022]
Abstract
Exposure of rats to elevated dietary salt following recovery from acute kidney injury (AKI) accelerates the transition to chronic kidney disease (CKD), and is dependent on lymphocyte activity. Here we tested whether high salt diet triggers lymphocyte activation in postischemic kidneys to worsen renal inflammation and fibrosis. Male Sprague-Dawley rats on a 0.4% salt diet were subjected to left unilateral ischemia-reperfusion and allowed to recover for 5 weeks. This resulted in a mild elevation of CD4(+) T cells relative to sham animals. Contralateral unilateral nephrectomy and elevated dietary salt (4%) for 4 extra weeks hastened CKD and interstitial fibrosis. Activated T cells were increased in the kidney threefold after 4 weeks of elevated dietary salt exposure relative to post-AKI rats before salt feeding. The T cell subset was largely positive for IL-17, indicative of Th-17 cells. Because angiotensin II activity may influence lymphocyte activation, injured rats were given the AT1R antagonist, losartan, along with high salt diet. This significantly reduced the number of renal Th-17 cells to levels of sham rats, and significantly reduced the salt-induced increase in fibrosis to about half. In vitro studies in AKI-primed CD4(+) T cells indicated that angiotensin II and extracellular sodium enhanced, and losartan inhibited, IL-17 expression. Thus, dietary salt modulates immune cell activity in postischemic recovering kidneys because of the activity of local RAS, suggesting the participation of these cells in CKD progression post-AKI.
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Affiliation(s)
- Purvi Mehrotra
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Jaymin B Patel
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Carlie M Ivancic
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Jason A Collett
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - David P Basile
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana, USA
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