801
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Ito Y, Tatsukawa H, Yamaguchi H, Takahashi K, Hitomi K, Yuzawa Y. Detection and identification of potential transglutaminase 2 substrates in the mouse renal glomeruli. Arch Biochem Biophys 2018; 660:11-19. [DOI: 10.1016/j.abb.2018.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 10/01/2018] [Accepted: 10/05/2018] [Indexed: 11/15/2022]
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802
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Metabolic reprogramming by the S-nitroso-CoA reductase system protects against kidney injury. Nature 2018; 565:96-100. [PMID: 30487609 PMCID: PMC6318002 DOI: 10.1038/s41586-018-0749-z] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 10/31/2018] [Indexed: 12/12/2022]
Abstract
Endothelial nitric oxide synthase (eNOS) is protective against kidney injury, but the molecular mechanisms of this protection are poorly understood1,2. Nitric oxide-based cellular signalling is generally mediated by protein S-nitrosylation, the oxidative modification of Cys residues to form S-nitrosothiols (SNOs). S-nitrosylation regulates proteins in all functional classes, and is controlled by enzymatic machinery that includes S-nitrosylases and denitrosylases, which add and remove SNO from proteins, respectively3,4. In Saccharomyces cerevisiae, the classic metabolic intermediate co-enzyme A (CoA) serves as an endogenous source of SNOs through its conjugation with nitric oxide to form S-nitroso-CoA (SNO-CoA), and S-nitrosylation of proteins by SNO-CoA is governed by its cognate denitrosylase, SNO-CoA reductase (SCoR)5. Mammals possess a functional homologue of yeast SCoR, an aldo-keto reductase family member (AKR1A1)5 with an unknown physiological role. Here we report that the SNO-CoA-AKR1A1 system is highly expressed in renal proximal tubules, where it transduces the activity of eNOS in reprogramming intermediary metabolism, thereby protecting kidneys against acute kidney injury. Specifically, deletion of Akr1a1 in mice to reduce SCoR activity increased protein S-nitrosylation, protected against acute kidney injury and improved survival, whereas this protection was lost when Enos (also known as Nos3) was also deleted. Metabolic profiling coupled with unbiased mass spectrometry-based SNO-protein identification revealed that protection by the SNO-CoA-SCoR system is mediated by inhibitory S-nitrosylation of pyruvate kinase M2 (PKM2) through a novel locus of regulation, thereby balancing fuel utilization (through glycolysis) with redox protection (through the pentose phosphate shunt). Targeted deletion of PKM2 from mouse proximal tubules recapitulated precisely the protective and mechanistic effects of S-nitrosylation in Akr1a1-/- mice, whereas Cys-mutant PKM2, which is refractory to S-nitrosylation, negated SNO-CoA bioactivity. Our results identify a physiological function of the SNO-CoA-SCoR system in mammals, describe new regulation of renal metabolism and of PKM2 in differentiated tissues, and offer a novel perspective on kidney injury with therapeutic implications.
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803
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Kikuchi H, Sasaki E, Nomura N, Mori T, Minamishima YA, Yoshizaki Y, Takahashi N, Furusho T, Arai Y, Mandai S, Yamashita T, Ando F, Maejima Y, Isobe K, Okado T, Rai T, Uchida S, Sohara E. Failure to sense energy depletion may be a novel therapeutic target in chronic kidney disease. Kidney Int 2018; 95:123-137. [PMID: 30455054 DOI: 10.1016/j.kint.2018.08.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 08/07/2018] [Accepted: 08/09/2018] [Indexed: 12/30/2022]
Abstract
The kidneys consume a large amount of energy to regulate volume status and blood pressure and to excrete uremic toxins. The identification of factors that cause energy mismatch in the setting of chronic kidney disease (CKD) and the development of interventions aimed at improving this mismatch are key research imperatives. Although the critical cellular energy sensor 5'-adenosine monophosphate (AMP)-activated protein kinase (AMPK) is known to be inactivated in CKD, the mechanism of AMPK dysregulation is unknown. In a mouse model of CKD, metabolome analysis confirmed a decrease in AMPK activation in the kidneys despite a high AMP: ATP ratio, suggesting that AMPK did not sense energy depletion. Similar AMPK inactivation was found in heart and skeletal muscle in CKD mice. Several uremic factors were shown to inactivate AMPK in vitro and in ex vivo preparations of kidney tissue. The specific AMPK activator A-769662, which bypasses the AMP sensing mechanism, ameliorated fibrosis and improved energy status in the kidneys of CKD mice, whereas an AMP analog did not. We further demonstrated that a low-protein diet activated AMPK independent of the AMP sensing mechanism, leading to improvement in energy metabolism and kidney fibrosis. These results suggest that a failure to sense AMP is the key mechanism underlying the vicious cycle of energy depletion and CKD progression and direct AMPK activation may be a novel therapeutic approach in CKD.
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Affiliation(s)
- Hiroaki Kikuchi
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Emi Sasaki
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Naohiro Nomura
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Takayasu Mori
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yoji Andrew Minamishima
- Division of Cell Biology, Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Yuki Yoshizaki
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Naohiro Takahashi
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Taisuke Furusho
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yohei Arai
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Shintaro Mandai
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Takahiro Yamashita
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Fumiaki Ando
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yasuhiro Maejima
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kiyoshi Isobe
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Tomokazu Okado
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Tatemitsu Rai
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Shinichi Uchida
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan.
| | - Eisei Sohara
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan.
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804
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Dissection of metabolic reprogramming in polycystic kidney disease reveals coordinated rewiring of bioenergetic pathways. Commun Biol 2018; 1:194. [PMID: 30480096 PMCID: PMC6240072 DOI: 10.1038/s42003-018-0200-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 10/22/2018] [Indexed: 02/08/2023] Open
Abstract
Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a genetic disorder caused by loss-of-function mutations in PKD1 or PKD2. Increased glycolysis is a prominent feature of the disease, but how it impacts on other metabolic pathways is unknown. Here, we present an analysis of mouse Pkd1 mutant cells and kidneys to investigate the metabolic reprogramming of this pathology. We show that loss of Pkd1 leads to profound metabolic changes that affect glycolysis, mitochondrial metabolism, and fatty acid synthesis (FAS). We find that Pkd1-mutant cells preferentially use glutamine to fuel the TCA cycle and to sustain FAS. Interfering with either glutamine uptake or FAS retards cell growth and survival. We also find that glutamine is diverted to asparagine via asparagine synthetase (ASNS). Transcriptional profiling of PKD1-mutant human kidneys confirmed these alterations. We find that silencing of Asns is lethal in Pkd1-mutant cells when combined with glucose deprivation, suggesting therapeutic approaches for ADPKD. Christine Podrini et al. present a comprehensive analysis of Pkd1 mutant mouse cells and kidneys, providing new insight into autosomal dominant polycystic kidney disease (ADPKD). They find that Pkd1 loss leads to profound metabolic changes, including asparagine synthase-driven glutamine anaplerosis.
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805
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Qi R, Yang C. Renal tubular epithelial cells: the neglected mediator of tubulointerstitial fibrosis after injury. Cell Death Dis 2018; 9:1126. [PMID: 30425237 PMCID: PMC6233178 DOI: 10.1038/s41419-018-1157-x] [Citation(s) in RCA: 151] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 10/06/2018] [Accepted: 10/18/2018] [Indexed: 02/07/2023]
Abstract
Renal fibrosis, especially tubulointerstitial fibrosis, is the inevitable outcome of all progressive chronic kidney diseases (CKDs) and exerts a great health burden worldwide. For a long time, interests in renal fibrosis have been concentrated on fibroblasts and myofibroblasts. However, in recent years, growing numbers of studies have focused on the role of tubular epithelial cells (TECs). TECs, rather than a victim or bystander, are probably a neglected mediator in renal fibrosis, responding to a variety of injuries. The maladaptive repair mechanisms of TECs may be the key point in this process. In this review, we will focus on the role of TECs in tubulointerstitial fibrosis. We will follow the fate of a tubular cell and depict the intracellular changes after injury. We will then discuss how the repair mechanism of tubular cells becomes maladaptive, and we will finally discuss the intercellular crosstalk in the interstitium that ultimately proceeds tubulointerstitial fibrosis.
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Affiliation(s)
- Ruochen Qi
- Department of Urology, Zhongshan Hospital, Fudan University, 200032, Shanghai, P. R. China
- Shanghai Medical College, Fudan University, 200032, Shanghai, P.R. China
| | - Cheng Yang
- Department of Urology, Zhongshan Hospital, Fudan University, 200032, Shanghai, P. R. China.
- Shanghai Key Laboratory of Organ Transplantation, 200032, Shanghai, P. R. China.
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806
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Lyu Z, Mao Z, Li Q, Xia Y, Liu Y, He Q, Wang Y, Zhao H, Lu Z, Zhou Q. PPARγ maintains the metabolic heterogeneity and homeostasis of renal tubules. EBioMedicine 2018; 38:178-190. [PMID: 30420298 PMCID: PMC6306377 DOI: 10.1016/j.ebiom.2018.10.072] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 10/22/2018] [Accepted: 10/31/2018] [Indexed: 02/03/2023] Open
Abstract
Background The renal tubules, which have distant metabolic features and functions in different segments, reabsorb >99% of approximately 180 l of water and 25,000 mmol of Na + daily. Defective metabolism in renal tubules is involved in the pathobiology of kidney diseases. However, the mechanisms underlying the metabolic regulation in renal tubules remain to be defined. Methods We quantitatively compared the proteomes of the isolated proximal tubules (PT) and distal tubules (DT) from C57BL/6 mouse using tandem mass tag (TMT) labeling-based quantitative mass spectrometry. Bioinformatics analysis of the differentially expressed proteins revealed the significant differences between PT and DT in metabolism pathway. We also performed in vitro and in vivo assays to investigate the molecular mechanism underlying the distant metabolic features in PT and DT. Findings We demonstrate that the renal proximal tubule (PT) has high expression of lipid metabolism enzymes, which is transcriptionally upregulated by abundantly expressed PPARα/γ. In contrast, the renal distal tubule (DT) has elevated glycolytic enzyme expression, which is mediated by highly expressed c-Myc. Importantly, PPARγ transcriptionally enhances the protease iRhom2 expression in PT, which suppresses EGF expression and secretion and subsequent EGFR-dependent glycolytic gene expression and glycolysis. PPARγ inhibition reduces iRhom2 expression and increases EGF and GLUT1 expression in PT in mice, resulting in renal tubule hypertrophy, tubulointerstitial fibrosis and damaged kidney functions, which are rescued by 2-deoxy-d-glucose treatment. Interpretation These findings delineate instrumental mechanisms underlying the active lipid metabolism and suppressed glycolysis in PT and active glycolysis in DT and reveal critical roles for PPARs and c-Myc in maintaining renal metabolic homeostasis. FUND: This work was supported by the National Natural Science Foundation of China (grants 81572076 and 81873932; to Q.Z.), the Applied Development Program of the Science and Technology Committee of Chongqing (cstc2014yykfB10003; Q.Z.), the Program of Populace Creativities Workshops of the Science and Technology Committee of Chongqing (Q.Z.), the special demonstration programs for innovation and application of techniques (cstc2018jscx-mszdX0022) from the Science and Technology Committee of Chongqing (Q.Z.).
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Affiliation(s)
- Zhongshi Lyu
- The Division of Molecular Nephrology, The M.O.E. Key Laboratory of Laboratory Medical Diagnostics, The School of Laboratory Medicine, Chongqing Medical University, Chongqing, People's Republic of China; Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Zhaomin Mao
- The Division of Molecular Nephrology, The M.O.E. Key Laboratory of Laboratory Medical Diagnostics, The School of Laboratory Medicine, Chongqing Medical University, Chongqing, People's Republic of China; Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Qianyin Li
- The Division of Molecular Nephrology, The M.O.E. Key Laboratory of Laboratory Medical Diagnostics, The School of Laboratory Medicine, Chongqing Medical University, Chongqing, People's Republic of China
| | - Yan Xia
- Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Yamin Liu
- The Division of Molecular Nephrology, The M.O.E. Key Laboratory of Laboratory Medical Diagnostics, The School of Laboratory Medicine, Chongqing Medical University, Chongqing, People's Republic of China
| | - Qingling He
- The Division of Molecular Nephrology, The M.O.E. Key Laboratory of Laboratory Medical Diagnostics, The School of Laboratory Medicine, Chongqing Medical University, Chongqing, People's Republic of China
| | - Yingchun Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Hui Zhao
- Key Laboratory for Regenerative Medicine, Ministry of Education, School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region
| | - Zhimin Lu
- Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX, USA
| | - Qin Zhou
- The Division of Molecular Nephrology, The M.O.E. Key Laboratory of Laboratory Medical Diagnostics, The School of Laboratory Medicine, Chongqing Medical University, Chongqing, People's Republic of China.
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807
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Clark SD, Song W, Cianciolo R, Lees G, Nabity M, Liu S. Abnormal Expression of miR-21 in Kidney Tissue of Dogs With X-Linked Hereditary Nephropathy: A Canine Model of Chronic Kidney Disease. Vet Pathol 2018; 56:93-105. [DOI: 10.1177/0300985818806050] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
MicroRNAs (miRNAs) are a group of small noncoding RNAs that act as regulators of posttranslational gene/protein expression and are known to play a key role in physiological and pathological processes. The objective of our study was to compare expression of miR-21 in renal tissue from dogs affected with chronic kidney disease (CKD) caused by X-linked hereditary nephropathy (XLHN), a disease equivalent to human Alport syndrome, to that from unaffected dogs. Additionally, we sought to characterize changes in relative mRNA expression of various genes associated with miR-21 function. miRNA was isolated from kidney tissue collected from both affected dogs and unaffected, age-matched littermates at defined milestones of disease progression, including end-stage renal disease (ESRD). Additionally, autopsy samples from affected dogs at ESRD and corresponding unaffected dogs were evaluated. Samples were scored based on histological changes, and relative expression of miR-21 and kidney disease-related genes was determined using quantitative real-time polymerase chain reaction. In affected dogs, significant upregulation of kidney miR-21 was first detected at the milestone corresponding with increased serum creatinine. Furthermore, miR-21 expression correlated significantly with urine protein: urine creatinine ratio, serum creatinine concentration, glomerular filtration rate, and histologic lesions (glomerular damage, tubular damage, chronic inflammation, and fibrosis). At end-stage disease, COL1A1, TGFB1 and its receptor, TGFB2, and Serpine1 were upregulated, while PPARA, PPARGC1A, ACADM, SOD1, and EGF were downregulated. In conclusion, miR-21 is abnormally upregulated in the kidneys of dogs with CKD caused by XLHN, which may play an important pathologic role in the progression of disease by dysregulating multiple pathways.
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Affiliation(s)
- Sabrina D. Clark
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | | | - Rachel Cianciolo
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - George Lees
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Mary Nabity
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, USA
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808
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Erpicum P, Rowart P, Defraigne JO, Krzesinski JM, Jouret F. What we need to know about lipid-associated injury in case of renal ischemia-reperfusion. Am J Physiol Renal Physiol 2018; 315:F1714-F1719. [PMID: 30332314 DOI: 10.1152/ajprenal.00322.2018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Renal segmental metabolism is reflected by the complex distribution of the main energy pathways along the nephron, with fatty acid oxidation preferentially used in the cortex area. Ischemia/reperfusion injury (IRI) is due to the restriction of renal blood flow, rapidly leading to a metabolic switch toward anaerobic conditions. Subsequent unbalance between energy demand and oxygen/nutrient delivery compromises kidney cell functions, resulting in a complex inflammatory cascade including the production of reactive oxygen species (ROS). Renal IRI especially involves lipid accumulation. Lipid peroxidation is one of the major events of ROS-associated tissue injury. Here, we briefly review the current knowledge of renal cell lipid metabolism in normal and ischemic conditions. Next, we focus on renal lipid-associated injury, with emphasis on its mechanisms and consequences during the course of IRI. Finally, we discuss preclinical observations aiming at preventing and/or attenuating lipid-associated IRI.
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Affiliation(s)
- Pauline Erpicum
- Division of Nephrology, University of Liège Academic Hospital , Liège , Belgium.,Groupe Interdisciplinaire de Génoprotéomique Appliquée, Cardiovascular Sciences, University of Liège , Liège , Belgium
| | - Pascal Rowart
- Groupe Interdisciplinaire de Génoprotéomique Appliquée, Cardiovascular Sciences, University of Liège , Liège , Belgium
| | - Jean-Olivier Defraigne
- Groupe Interdisciplinaire de Génoprotéomique Appliquée, Cardiovascular Sciences, University of Liège , Liège , Belgium.,Division of Cardio-Thoracic Surgery, University of Liège Academic Hospital , Liège , Belgium
| | | | - François Jouret
- Division of Nephrology, University of Liège Academic Hospital , Liège , Belgium.,Groupe Interdisciplinaire de Génoprotéomique Appliquée, Cardiovascular Sciences, University of Liège , Liège , Belgium
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809
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Øvrehus MA, Bruheim P, Ju W, Zelnick LR, Langlo KA, Sharma K, de Boer IH, Hallan SI. Gene Expression Studies and Targeted Metabolomics Reveal Disturbed Serine, Methionine, and Tyrosine Metabolism in Early Hypertensive Nephrosclerosis. Kidney Int Rep 2018; 4:321-333. [PMID: 30775629 PMCID: PMC6365407 DOI: 10.1016/j.ekir.2018.10.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/04/2018] [Accepted: 10/08/2018] [Indexed: 02/07/2023] Open
Abstract
Introduction Hypertensive nephrosclerosis is among the leading causes of end-stage renal disease, but its pathophysiology is poorly understood. We wanted to explore early metabolic changes using gene expression and targeted metabolomics analysis. Methods We analyzed gene expression in kidneys biopsied from 20 patients with nephrosclerosis and 31 healthy controls with an Affymetrix array. Thirty-one amino acids were measured by liquid chromatography coupled with mass spectrometry (LC-MS) in urine samples from 62 patients with clinical hypertensive nephrosclerosis and 33 age- and sex-matched healthy controls, and major findings were confirmed in an independent cohort of 45 cases and 15 controls. Results Amino acid catabolism and synthesis were strongly underexpressed in hypertensive nephrosclerosis (13- and 7-fold, respectively), and these patients also showed gene expression patterns indicating decreased fatty acid oxidation (12-fold) and increased interferon gamma (10-fold) and cellular defense response (8-fold). Metabolomics analysis revealed significant distribution differences in 11 amino acids in hypertensive nephrosclerosis, among them tyrosine, phenylalanine, dopamine, homocysteine, and serine, with 30% to 70% lower urine excretion. These findings were replicated in the independent cohort. Integrated gene-metabolite pathway analysis showed perturbations of renal dopamine biosynthesis. There were also significant differences in homocysteine/methionine homeostasis and the serine pathway, which have strong influence on 1-carbon metabolism. Several of these disturbances could be interconnected through reduced regeneration of tetrahydrofolate and tetrahydrobiopterin. Conclusion Early hypertensive nephrosclerosis showed perturbations of intrarenal biosynthesis of dopamine, which regulates natriuresis and blood pressure. There were also disturbances in serine/glycine and methionine/homocysteine metabolism, which may contribute to endothelial dysfunction, atherosclerosis, and renal fibrosis.
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Affiliation(s)
- Marius A Øvrehus
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Nephrology, St Olav Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Per Bruheim
- Department of Biotechnology and Food Science, Norwegian University of Science and Technology, Trondheim, Norway
| | - Wenjun Ju
- Division of Nephrology, Department of Medicine, University of Michigan, Ann Arbor, Michigan, USA.,Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, USA
| | - Leila R Zelnick
- Kidney Research Institute, University of Washington, Seattle, Washington, USA.,Division of Nephrology, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Knut A Langlo
- Department of Nephrology, St Olav Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Kumar Sharma
- University of Texas Health San Antonio, San Antonio, Texas, USA
| | - Ian H de Boer
- Kidney Research Institute, University of Washington, Seattle, Washington, USA.,Division of Nephrology, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Stein I Hallan
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Nephrology, St Olav Hospital, Trondheim University Hospital, Trondheim, Norway
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810
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Renal tubules transcriptome reveals metabolic maladaption during the progression of ischemia-induced acute kidney injury. Biochem Biophys Res Commun 2018; 505:432-438. [PMID: 30266403 DOI: 10.1016/j.bbrc.2018.08.111] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 08/16/2018] [Indexed: 11/22/2022]
Abstract
Renal tubular epithelial cells (TECs) play a critical role in driving acute kidney injury (AKI) progression, but the key molecular features in TECs during this process is not clear. To better understand the molecular characteristics in renal TECs during AKI and renal fibrogenesis, an irreversible AKI mouse model induced by ischemia/reperfusion injury (IRI) was used in this study. The renal tubules were isolated and tubule specific transcriptome was detected by RNA-seq at different stages in the progression of AKI in this model. The overall transcriptome indicated injury and repair process of TEC after renal IRI. In addition, metabolism maladaption was observed during AKI progression to chronic fibrosis. Particularly, we found dysregulation of multiple steps of lipid metabolism in tubule transcriptomes. Oil red O staining revealed massive lipid droplets accumulation in TECs at day 10, thus confirming the defect of lipid metabolism. This is the first study to charaterize renal tubule specific transcriptome during AKI progression. The results shed light on the molecular features in TECs for progressive AKI.
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811
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Yang X, Xu W, Huang K, Zhang B, Wang H, Zhang X, Gong L, Luo Y, He X. Precision toxicology shows that troxerutin alleviates ochratoxin A-induced renal lipotoxicity. FASEB J 2018; 33:2212-2227. [PMID: 30247986 DOI: 10.1096/fj.201800742r] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Lipotoxicity is the most common cause of severe kidney disease, with few treatment options available today. Precision toxicology can improve detection of subtle intracellular changes in response to exogenous substrates; thus, it facilitates in-depth research on bioactive molecules that may interfere with the onset of certain diseases. In the current study, troxerutin significantly relieved nephrotoxicity, increased endurance, and improved systemic energy metabolism and renal inflammation in OTA-induced nephrotic mice. Lipidomics showed that troxerutin effectively reduced the levels of triglycerides, phosphatidylcholines, and phosphatidylethanolamines in nephropathy. The mechanism was partly attributable to troxerutin in alleviating the aberrantly up-regulated expression of sphingomyelinase, the cystic fibrosis transmembrane conductance regulator, and chloride channel 2. Renal tubular epithelial cells, the main site of toxin-induced accumulation of lipids in the kidney, were subjected to transcriptomic profiling, which uncovered several metabolic factors relevant to aberrant lipid and lipoprotein metabolism. Our work provides new insights into the molecular features of toxin-induced lipotoxicity in renal tubular epithelial cells in vivo and demonstrates the function of troxerutin in alleviating OTA-induced nephrosis and associated systemic energy metabolism disorders.-Yang, X., Xu, W., Huang, K., Zhang, B., Wang, H., Zhang, X., Gong, L., Luo, Y., He, X. Precision toxicology shows that troxerutin alleviates ochratoxin A-induced renal lipotoxicity.
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Affiliation(s)
- Xuan Yang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Wentao Xu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Beijing Laboratory for Food Quality and Safety, Beijing, China
| | - Kunlun Huang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Beijing Laboratory for Food Quality and Safety, Beijing, China
| | - Boyang Zhang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Haomiao Wang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Xueqin Zhang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Lijing Gong
- China Academy of Sport and Health Sciences, Beijing Sport University, Beijing, China
| | - Yunbo Luo
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Key Laboratory of Safety Assessment of Genetically Modified Organism-Food Safety, Ministry of Agriculture, China
| | - Xiaoyun He
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Key Laboratory of Safety Assessment of Genetically Modified Organism-Food Safety, Ministry of Agriculture, China
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812
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Srivastava SP, Li J, Kitada M, Fujita H, Yamada Y, Goodwin JE, Kanasaki K, Koya D. SIRT3 deficiency leads to induction of abnormal glycolysis in diabetic kidney with fibrosis. Cell Death Dis 2018; 9:997. [PMID: 30250024 PMCID: PMC6155322 DOI: 10.1038/s41419-018-1057-0] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 07/03/2018] [Accepted: 08/02/2018] [Indexed: 12/26/2022]
Abstract
The regulation of aberrant glucose metabolism in diabetes associated-kidney fibrosis is not well known. In this study we found the suppression of SIRT3 protein level in diabetic kidney, displays responsibility in fibrogenic programming associated with aberrant glycolysis and such abnormal glycolysis is the therapeutic target in diabetes associated-kidney fibrosis. When analyzing different strains of streptozotocin-induced diabetic mice model (fibrotic model: CD-1, less fibrotic model: C57Bl6), we found SIRT3 suppression was associated with kidney fibrosis in fibrotic CD-1; further SIRT3 suppression by systemic administration of SIRT3 siRNA in the diabetic mice, showed profound fibrogenic phenotype in the kidney. Such suppression in SIRT3 was associated with the induction of transforming growth factor-β (TGF-β)/smad signaling, higher level of HIF1α accumulation and PKM2 dimer formation; these alterations subsequently led to abnormal glycolysis and linked abnormal mesenchymal transformations in vivo and in vitro. Inhibition of such aberrant glycolysis suppressed fibrogenic programming and restored SIRT3 level as well. Such aberrant glycolysis was confirmed in the KK/Ta-Ins2Akita mouse, the mouse model of progressive diabetic kidney disease. These data demonstrate that SIRT3 deficiency promotes abnormal glycolysis which is responsible for the fibrogenic pathway in diabetic kidney. Restoration of SIRT3 could be an alternative strategy in combating diabetes associated-kidney fibrosis via inhibition of aberrant glycolysis.
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Affiliation(s)
- Swayam Prakash Srivastava
- Department of Diabetology & Endocrinology, Kanazawa Medical University, Uchinada, Ishikawa, 920-0293, Japan.,Department of Pediatrics (Nephrology) Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Jinpeng Li
- Department of Diabetology & Endocrinology, Kanazawa Medical University, Uchinada, Ishikawa, 920-0293, Japan
| | - Munehiro Kitada
- Department of Diabetology & Endocrinology, Kanazawa Medical University, Uchinada, Ishikawa, 920-0293, Japan.,Division of Anticipatory Molecular Food Science and Technology, Kanazawa Medical University, Uchinada, Ishikawa, 920-0293, Japan
| | - Hiroki Fujita
- Department of Endocrinology, Diabetes and Geriatric Medicine, Akita University Graduate School of Medicine, Akita, 010-8543, Japan
| | - Yuichiro Yamada
- Department of Endocrinology, Diabetes and Geriatric Medicine, Akita University Graduate School of Medicine, Akita, 010-8543, Japan
| | - Julie E Goodwin
- Department of Pediatrics (Nephrology) Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Keizo Kanasaki
- Department of Diabetology & Endocrinology, Kanazawa Medical University, Uchinada, Ishikawa, 920-0293, Japan. .,Division of Anticipatory Molecular Food Science and Technology, Kanazawa Medical University, Uchinada, Ishikawa, 920-0293, Japan.
| | - Daisuke Koya
- Department of Diabetology & Endocrinology, Kanazawa Medical University, Uchinada, Ishikawa, 920-0293, Japan. .,Division of Anticipatory Molecular Food Science and Technology, Kanazawa Medical University, Uchinada, Ishikawa, 920-0293, Japan.
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813
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Zhang ZH, Li MH, Liu D, Chen H, Chen DQ, Tan NH, Ma SC, Zhao YY. Rhubarb Protect Against Tubulointerstitial Fibrosis by Inhibiting TGF-β/Smad Pathway and Improving Abnormal Metabolome in Chronic Kidney Disease. Front Pharmacol 2018; 9:1029. [PMID: 30271345 PMCID: PMC6146043 DOI: 10.3389/fphar.2018.01029] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 08/24/2018] [Indexed: 12/01/2022] Open
Abstract
Tubulointerstitial fibrosis is the final common pathway for all kidney diseases leading to chronic kidney disease (CKD). TGF-β/Smad signaling pathway plays a key role in renal fibrosis. Previous studies have revealed that rhubarb extracts attenuated the increase of transforming growth factor-β 1 (TGF-β1) in CKD rats. To gain an in-depth insight into the mechanism of the anti-fibrotic activities of the rhubarb extracts, we investigated the influence of rhubarb extracts on TGF-β/Smad signaling pathway and the influence on metabolome in a rat model of CKD with adenine-induced chronic tubulointerstitial nephropathy. Male Sprague-Dawley rats were divided into four groups, including control, CKD, CKD + petroleum ether extract, CKD + ethyl acetate extract, and CKD + n-butanol extract groups. Kidneys harvested on the week three were evaluated for renal fibrosis, the expression of proteins in TGF-β/Smad signaling pathway and metabolomic study. We found rhubarb extracts suppressed TGF-β/Smad3-mediated renal fibrosis by reducing the TGF-β1, transforming growth factor-β receptor I (TGF-β RI), transforming growth factor-β receptor II (TGF-β RII), Smad2, p-Smad2, Smad3, p-Smad3, and Smad4, meanwhile increased Smad7. In addition, rhubarb extracts mitigated renal injury and dysfunction, and either fully or partially reversed the abnormalities of tissue metabolites. Thus, rebalancing the disorder of TGF-β/Smad signaling and metabolic dysfunction by treatment with rhubarb extracts may represent as an effective therapy for CKD associated with fibrosis.
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Affiliation(s)
- Zhi-Hao Zhang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Life Sciences, Northwest University, Xi'an, China.,State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Ming-Hua Li
- National Institutes for Food and Drug Control, State Food and Drug Administration, Beijing, China
| | - Dan Liu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Life Sciences, Northwest University, Xi'an, China
| | - Hua Chen
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Life Sciences, Northwest University, Xi'an, China
| | - Dan-Qian Chen
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Life Sciences, Northwest University, Xi'an, China
| | - Ning-Hua Tan
- State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Shuang-Cheng Ma
- National Institutes for Food and Drug Control, State Food and Drug Administration, Beijing, China
| | - Ying-Yong Zhao
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Life Sciences, Northwest University, Xi'an, China
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814
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Huang S, Park J, Qiu C, Chung KW, Li SY, Sirin Y, Han SH, Taylor V, Zimber-Strobl U, Susztak K. Jagged1/Notch2 controls kidney fibrosis via Tfam-mediated metabolic reprogramming. PLoS Biol 2018; 16:e2005233. [PMID: 30226866 PMCID: PMC6161902 DOI: 10.1371/journal.pbio.2005233] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 09/28/2018] [Accepted: 09/03/2018] [Indexed: 12/14/2022] Open
Abstract
While Notch signaling has been proposed to play a key role in fibrosis, the direct molecular pathways targeted by Notch signaling and the precise ligand and receptor pair that are responsible for kidney disease remain poorly defined. In this study, we found that JAG1 and NOTCH2 showed the strongest correlation with the degree of interstitial fibrosis in a genome-wide expression analysis of a large cohort of human kidney samples. Transcript analysis of mouse kidney disease models, including folic-acid (FA)-induced nephropathy, unilateral ureteral obstruction (UUO), or apolipoprotein L1 (APOL1)-associated kidney disease, indicated that Jag1 and Notch2 levels were higher in all analyzed kidney fibrosis models. Mice with tubule-specific deletion of Jag1 or Notch2 (Kspcre/Jag1flox/flox and Kspcre/Notch2flox/flox) had no kidney-specific alterations at baseline but showed protection from FA-induced kidney fibrosis. Tubule-specific genetic deletion of Notch1 and global knockout of Notch3 had no effect on fibrosis. In vitro chromatin immunoprecipitation experiments and genome-wide expression studies identified the mitochondrial transcription factor A (Tfam) as a direct Notch target. Re-expression of Tfam in tubule cells prevented Notch-induced metabolic and profibrotic reprogramming. Tubule-specific deletion of Tfam resulted in fibrosis. In summary, Jag1 and Notch2 play a key role in kidney fibrosis development by regulating Tfam expression and metabolic reprogramming.
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Affiliation(s)
- Shizheng Huang
- Renal Electrolyte and Hypertension Division, Department of Medicine, Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jihwan Park
- Renal Electrolyte and Hypertension Division, Department of Medicine, Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Chengxiang Qiu
- Renal Electrolyte and Hypertension Division, Department of Medicine, Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Ki Wung Chung
- Renal Electrolyte and Hypertension Division, Department of Medicine, Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Szu-yuan Li
- Renal Electrolyte and Hypertension Division, Department of Medicine, Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Yasemin Sirin
- Renal Electrolyte and Hypertension Division, Department of Medicine, Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Seung Hyeok Han
- Renal Electrolyte and Hypertension Division, Department of Medicine, Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Verdon Taylor
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Ursula Zimber-Strobl
- Research Unit Gene Vectors, Helmholtz Zentrum München, German Research Center for Environment and Health, Munich, Germany
| | - Katalin Susztak
- Renal Electrolyte and Hypertension Division, Department of Medicine, Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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815
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Sanchez DJ, Steger DJ, Skuli N, Bansal A, Simon MC. PPARγ is dispensable for clear cell renal cell carcinoma progression. Mol Metab 2018; 14:139-149. [PMID: 29866440 PMCID: PMC6034040 DOI: 10.1016/j.molmet.2018.05.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 05/11/2018] [Accepted: 05/17/2018] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE Clear cell renal cell carcinoma (ccRCC) is a subtype of kidney cancer defined by robust lipid accumulation, which prior studies have indicated plays an important role in tumor progression. We hypothesized that the peroxisome proliferator-activated receptor gamma (PPARγ), detected in both ccRCC tumors and cell lines, promotes lipid storage in ccRCC and contributes to tumorigenesis in this setting. PPARγ transcriptionally regulates a number of genes involved in lipid and glucose metabolism in adipocytes, yet its role in ccRCC has not been described. The objective of this study was to elucidate endogenous PPARγ function in ccRCC cells. METHODS AND RESULTS Using chromatin immunoprecipitation followed by deep sequencing (ChIP-seq), we found that PPARγ and its heterodimer RXR occupy the canonical DR1 PPAR binding motif at approximately 1000 locations throughout the genome that can be subdivided into adipose-shared and ccRCC-specific sites. CRISPR-Cas9 mediated, loss-of-function studies determined that PPARγ is dispensable for viability, proliferation, and migration of ccRCC cells in vitro and in vivo. Also, surprisingly, PPARγ deletion had little effect on the robust lipid accumulation that typifies the "clear cell" phenotype of kidney cancer. CONCLUSION Our results suggest that PPARγ plays neither a tumor suppressive nor oncogenic role in advanced ccRCC, and thus single-agent therapeutics targeting PPARγ are unlikely to be effective for the treatment of this disease. The unique cistrome of PPARγ in ccRCC cells demonstrates the importance of cell type in determining the functions of PPARγ.
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Affiliation(s)
- Danielle J Sanchez
- Abramson Family Cancer Research Institute, USA; Department of Cell and Developmental Biology, USA
| | | | - Nicolas Skuli
- Abramson Family Cancer Research Institute, USA; Department of Cancer Biology, USA
| | - Ankita Bansal
- Abramson Family Cancer Research Institute, USA; Department of Cancer Biology, USA
| | - M Celeste Simon
- Abramson Family Cancer Research Institute, USA; Department of Cell and Developmental Biology, USA.
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816
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Trasino SE, Tang XH, Shevchuk MM, Choi ME, Gudas LJ. Amelioration of Diabetic Nephropathy Using a Retinoic Acid Receptor β2 Agonist. J Pharmacol Exp Ther 2018; 367:82-94. [PMID: 30054312 DOI: 10.1124/jpet.118.249375] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 07/20/2018] [Indexed: 12/17/2022] Open
Abstract
Vitamin A (VA) and its derivatives, known as retinoids, play critical roles in renal development through retinoic acid receptor β2 (RARβ2). Disruptions in VA signaling pathways are associated with the onset of diabetic nephropathy (DN). Despite the known role of RARβ2 in renal development, the effects of selective agonists for RARβ2 in a high-fat diet (HFD) model of DN are unknown. Here we examined whether AC261066 (AC261), a highly selective agonist for RARβ2, exhibited therapeutic effects in a HFD model of DN in C57BL/6 mice. Twelve weeks of AC261 administration to HFD-fed mice was well tolerated with no observable side effects. Compared with HFD-fed mice, HFD + AC261-treated mice had improved glycemic control and reductions in proteinuria and urine albumin-to-creatinine ratio. Several cellular hallmarks of DN were mitigated in HFD + AC261-treated mice, including reductions in tubule lipid droplets, podocyte (POD) effacement, endothelial cell collapse, mesangial expansion, and glomerular basement membrane thickening. Mesangial and tubule interstitial expression of the myofibroblast markers α-smooth muscle actin (α-SMA) and type IV collagen (Col-IV) was lower in HFD + AC261-treated mice compared with HFD alone. Ultrastructural and immunohistochemistry analyses showed that, compared with HFD-fed mice, HFD + AC261-treated mice showed preservation of POD foot process and slit-diaphragm morphology, an increase in the levels of slit-diagram protein podocin, and the transcription factor Wilms tumor-suppressor gene 1 in PODs. Given the need for novel DN therapies, our results warrant further studies of the therapeutic properties of AC261 in DN.
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Affiliation(s)
- Steven E Trasino
- Departments of Pharmacology (S.E.T., X.-H.T., L.J.G.) and Pathology (M.M.S.) and Division of Nephrology and Hypertension, Department of Medicine (M.E.C.), Weill Cornell Medical College of Cornell University, School of Urban Public Health, Nutrition Program, Hunter College, City University of New York (S.E.T.), and NewYork-Presbyterian Hospital-Weill Cornell Medical Center (M.E.C.), New York, New York
| | - Xiao-Han Tang
- Departments of Pharmacology (S.E.T., X.-H.T., L.J.G.) and Pathology (M.M.S.) and Division of Nephrology and Hypertension, Department of Medicine (M.E.C.), Weill Cornell Medical College of Cornell University, School of Urban Public Health, Nutrition Program, Hunter College, City University of New York (S.E.T.), and NewYork-Presbyterian Hospital-Weill Cornell Medical Center (M.E.C.), New York, New York
| | - Maria M Shevchuk
- Departments of Pharmacology (S.E.T., X.-H.T., L.J.G.) and Pathology (M.M.S.) and Division of Nephrology and Hypertension, Department of Medicine (M.E.C.), Weill Cornell Medical College of Cornell University, School of Urban Public Health, Nutrition Program, Hunter College, City University of New York (S.E.T.), and NewYork-Presbyterian Hospital-Weill Cornell Medical Center (M.E.C.), New York, New York
| | - Mary E Choi
- Departments of Pharmacology (S.E.T., X.-H.T., L.J.G.) and Pathology (M.M.S.) and Division of Nephrology and Hypertension, Department of Medicine (M.E.C.), Weill Cornell Medical College of Cornell University, School of Urban Public Health, Nutrition Program, Hunter College, City University of New York (S.E.T.), and NewYork-Presbyterian Hospital-Weill Cornell Medical Center (M.E.C.), New York, New York
| | - Lorraine J Gudas
- Departments of Pharmacology (S.E.T., X.-H.T., L.J.G.) and Pathology (M.M.S.) and Division of Nephrology and Hypertension, Department of Medicine (M.E.C.), Weill Cornell Medical College of Cornell University, School of Urban Public Health, Nutrition Program, Hunter College, City University of New York (S.E.T.), and NewYork-Presbyterian Hospital-Weill Cornell Medical Center (M.E.C.), New York, New York
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817
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Lee M, Katerelos M, Gleich K, Galic S, Kemp BE, Mount PF, Power DA. Phosphorylation of Acetyl-CoA Carboxylase by AMPK Reduces Renal Fibrosis and Is Essential for the Anti-Fibrotic Effect of Metformin. J Am Soc Nephrol 2018; 29:2326-2336. [PMID: 29976587 DOI: 10.1681/asn.2018010050] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 06/18/2018] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Expression of genes regulating fatty acid metabolism is reduced in tubular epithelial cells from kidneys with tubulointerstitial fibrosis (TIF), thus decreasing the energy produced by fatty acid oxidation (FAO). Acetyl-CoA carboxylase (ACC), a target for the energy-sensing AMP-activating protein kinase (AMPK), is the major controller of the rate of FAO within cells. Metformin has a well described antifibrotic effect, and increases phosphorylation of ACC by AMPK, thereby increasing FAO. METHODS We evaluated phosphorylation of ACC in cell and mouse nephropathy models, as well as the effects of metformin administration in mice with and without mutations that reduce ACC phosphorylation. RESULTS Reduced phosphorylation of ACC on the AMPK site Ser79 occurred in both tubular epithelial cells treated with folate to mimic cellular injury and in wild-type (WT) mice after induction of the folic acid nephropathy model. When this effect was exaggerated in mice with knock-in (KI) Ser to Ala mutations of the phosphorylation sites in ACC, lipid accumulation and fibrosis increased significantly compared with WT. The effect of ACC phosphorylation on fibrosis was confirmed in the unilateral ureteric obstruction model, which showed significantly increased lipid accumulation and fibrosis in the KI mice. Metformin use was associated with significantly reduced fibrosis and lipid accumulation in WT mice. In contrast, in the KI mice, the drug was associated with worsened fibrosis. CONCLUSIONS These data indicate that reduced phosphorylation of ACC after renal injury contributes to the development of TIF, and that phosphorylation of ACC is required for metformin's antifibrotic action in the kidney.
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Affiliation(s)
- Mardiana Lee
- Kidney Laboratory, Department of Nephrology, and.,Department of Medicine, The University of Melbourne, Heidelberg and Fitzroy, Victoria, Australia
| | | | - Kurt Gleich
- Kidney Laboratory, Department of Nephrology, and
| | - Sandra Galic
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia; and
| | - Bruce E Kemp
- Department of Medicine, The University of Melbourne, Heidelberg and Fitzroy, Victoria, Australia.,St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia; and.,Mary MacKillop Institute for Health Research, Australian Catholic University, Fitzroy, Victoria, Australia
| | - Peter F Mount
- Kidney Laboratory, Department of Nephrology, and.,Department of Medicine, The University of Melbourne, Heidelberg and Fitzroy, Victoria, Australia.,The Institute for Breathing and Sleep, Austin Health, Heidelberg, Victoria, Australia
| | - David A Power
- Kidney Laboratory, Department of Nephrology, and .,Department of Medicine, The University of Melbourne, Heidelberg and Fitzroy, Victoria, Australia.,The Institute for Breathing and Sleep, Austin Health, Heidelberg, Victoria, Australia
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818
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Sanchez DJ, Simon MC. Genetic and metabolic hallmarks of clear cell renal cell carcinoma. Biochim Biophys Acta Rev Cancer 2018; 1870:23-31. [PMID: 29959988 DOI: 10.1016/j.bbcan.2018.06.003] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 06/20/2018] [Accepted: 06/20/2018] [Indexed: 12/20/2022]
Abstract
Clear cell renal cell carcinoma (ccRCC) is a malignancy characterized by deregulated hypoxia-inducible factor signaling, mutation of several key chromatin modifying enzymes, and numerous alterations in cellular metabolism. Pre-clinical studies have historically been limited to cell culture models, however, the identification of critical tumor suppressors and oncogenes from large-scale patient sequencing data has led to several new genetically engineered mouse models with phenotypes reminiscent of ccRCC. In this review, we summarize recent literature on these topics and discuss how they inform targeted therapeutic approaches for the treatment of ccRCC.
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Affiliation(s)
- Danielle J Sanchez
- Abramson Family Cancer Research Institute, 456 BRB II/III, 421 Curie Boulevard, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104-6160, USA; Department of Cell and Developmental Biology, 456 BRB II/III, 421 Curie Boulevard, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104-6160, USA
| | - M Celeste Simon
- Abramson Family Cancer Research Institute, 456 BRB II/III, 421 Curie Boulevard, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104-6160, USA; Department of Cell and Developmental Biology, 456 BRB II/III, 421 Curie Boulevard, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104-6160, USA.
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819
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Yan Q, Song Y, Zhang L, Chen Z, Yang C, Liu S, Yuan X, Gao H, Ding G, Wang H. Autophagy activation contributes to lipid accumulation in tubular epithelial cells during kidney fibrosis. Cell Death Discov 2018; 4:2. [PMID: 30062051 PMCID: PMC6060103 DOI: 10.1038/s41420-018-0065-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 05/14/2018] [Indexed: 12/25/2022] Open
Abstract
Sustained activation of autophagy and lipid accumulation in tubular epithelial cells (TECs) are both associated with the kidney fibrosis progression. Autophagy has been found involved in the lipid metabolism regulation through a bi-directional mechanism of inducing lipolysis as well as promoting lipid droplet formation. However, whether and how autophagy influences lipid accumulation in kidney fibrosis remain unclear. In the current study, we show that UUO-induced lipid accumulation in tubular cells was significantly reduced when the pharmacological inhibitor 3-MA or CQ was administrated both in vivo and in vitro. Of interest, colocalization of LDs and autophagosomes, as well as colocalization of LDs and lysosomes were undetected in UUO-induced fibrotic kidneys, although lysosome function remained robust, indicating the lipid accumulation is lipophagy-lysosome pathway independent. TGF-β1-induced lipid droplets formation in HK-2 cells were decreased when the Beclin-1 expression was silenced, implying that autophagy-upregulated lipid droplets formation is Beclin-1 dependent. Finally, CQ treatment of UUO-induced fibrotic kidneys reduced the expression of α-SMA and tubular cell apoptosis and rescued the expression of E-cadherin, which was associated with the ameliorated lipid deposition. Therefore, our work documented that autophagy promotes lipid droplet formation in TECs in a Beclin-1-dependent manner, which causes renal lipotoxicity and contributes to the progression of kidney fibrosis.
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Affiliation(s)
- Qi Yan
- 1Department of Nephrology, Renmin hospital of Wuhan University, Wuhan, China.,2Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yuan Song
- 1Department of Nephrology, Renmin hospital of Wuhan University, Wuhan, China
| | - Lu Zhang
- 1Department of Nephrology, Renmin hospital of Wuhan University, Wuhan, China
| | - Zhaowei Chen
- 1Department of Nephrology, Renmin hospital of Wuhan University, Wuhan, China
| | - Cheng Yang
- 1Department of Nephrology, Renmin hospital of Wuhan University, Wuhan, China
| | - Shan Liu
- 3Department of Nephrology, University Hospital of Hubei University for Nationalities, Enshi, China
| | - Xiaohan Yuan
- 1Department of Nephrology, Renmin hospital of Wuhan University, Wuhan, China
| | - Hongyu Gao
- 2Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Guohua Ding
- 1Department of Nephrology, Renmin hospital of Wuhan University, Wuhan, China
| | - Huiming Wang
- 1Department of Nephrology, Renmin hospital of Wuhan University, Wuhan, China
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820
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Ding W, Yousefi K, Shehadeh LA. Isolation, Characterization, And High Throughput Extracellular Flux Analysis of Mouse Primary Renal Tubular Epithelial Cells. J Vis Exp 2018. [PMID: 29985358 PMCID: PMC6101965 DOI: 10.3791/57718] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mitochondrial dysfunction in the renal tubular epithelial cells (TECs) can lead to renal fibrosis, a major cause of chronic kidney disease (CKD). Therefore, assessing mitochondrial function in primary TECs may provide valuable insight into the bioenergetic status of the cells, providing insight into the pathophysiology of CKD. While there are a number of complex protocols available for the isolation and purification of proximal tubules in different species, the field lacks a cost-effective method optimized for tubular cell isolation without the need for purification. Here, we provide an isolation protocol that allows for studies focusing on both primary mouse proximal and distal renal TECs. In addition to cost-effective reagents and minimal animal procedures required in this protocol, the isolated cells maintain high energy levels after isolation and can be sub-cultured up to four passages, allowing for continuous studies. Furthermore, using a high throughput extracellular flux analyzer, we assess the mitochondrial respiration directly in the isolated TECs in a 96-well plate for which we provide recommendations for the optimization of cell density and compound concentration. These observations suggest that this protocol can be used for renal tubular ex vivo studies with a consistent, well-standardized production of renal TECs. This protocol may have broader future applications to study mitochondrial dysfunction associated with renal disorders for drug discovery or drug characterization purposes.
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Affiliation(s)
- Wen Ding
- Department of Molecular and Cellular Pharmacology, University of Miami Leonard M. Miller School of Medicine; Interdisciplinary Stem Cell Institute, University of Miami Leonard M. Miller School of Medicine
| | - Keyvan Yousefi
- Department of Molecular and Cellular Pharmacology, University of Miami Leonard M. Miller School of Medicine; Interdisciplinary Stem Cell Institute, University of Miami Leonard M. Miller School of Medicine
| | - Lina A Shehadeh
- Interdisciplinary Stem Cell Institute, University of Miami Leonard M. Miller School of Medicine; Department of Medicine, Division of Cardiology, University of Miami Leonard M. Miller School of Medicine; Vascular Biology Institute, University of Miami Leonard M. Miller School of Medicine; Peggy and Harold Katz Family Drug Discovery Center, University of Miami Leonard M. Miller School of Medicine;
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821
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Jha P, McDevitt MT, Halilbasic E, Williams EG, Quiros PM, Gariani K, Sleiman MB, Gupta R, Ulbrich A, Jochem A, Coon JJ, Trauner M, Pagliarini DJ, Auwerx J. Genetic Regulation of Plasma Lipid Species and Their Association with Metabolic Phenotypes. Cell Syst 2018; 6:709-721.e6. [PMID: 29909275 PMCID: PMC6397773 DOI: 10.1016/j.cels.2018.05.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 04/24/2018] [Accepted: 05/11/2018] [Indexed: 02/07/2023]
Abstract
The genetic regulation and physiological impact of most lipid species are unexplored. Here, we profiled 129 plasma lipid species across 49 strains of the BXD mouse genetic reference population fed either chow or a high-fat diet. By integrating these data with genomics and phenomics datasets, we elucidated genes by environment (diet) interactions that regulate systemic metabolism. We found quantitative trait loci (QTLs) for ~94% of the lipids measured. Several QTLs harbored genes associated with blood lipid levels and abnormal lipid metabolism in human genome-wide association studies. Lipid species from different classes provided signatures of metabolic health, including seven plasma triglyceride species that associated with either healthy or fatty liver. This observation was further validated in an independent mouse model of non-alcoholic fatty liver disease (NAFLD) and in plasma from NAFLD patients. This work provides a resource to identify plausible genes regulating the measured lipid species and their association with metabolic traits. Jha et al. provide a resource of genetic loci regulating individual plasma lipid species identified by studying a large mouse population and demonstrate the potential of lipid species to reflect metabolic health status of individuals. Several lipid-regulating loci in the mouse population harbor genes associated with abnormal lipid metabolism in human GWAS. The potential of lipid species to reflect health status was validated in dietary and therapeutic models of NAFLD in mice and human NAFLD patients.
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Affiliation(s)
- Pooja Jha
- Laboratory of Integrative and Systems Physiology, École Polytchnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Molly T McDevitt
- Morgridge Institute for Research, Madison, WI 53715, USA; Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Emina Halilbasic
- Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Evan G Williams
- Laboratory of Integrative and Systems Physiology, École Polytchnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Pedro M Quiros
- Laboratory of Integrative and Systems Physiology, École Polytchnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Karim Gariani
- Laboratory of Integrative and Systems Physiology, École Polytchnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Maroun B Sleiman
- Laboratory of Integrative and Systems Physiology, École Polytchnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Rahul Gupta
- Morgridge Institute for Research, Madison, WI 53715, USA
| | - Arne Ulbrich
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Adam Jochem
- Morgridge Institute for Research, Madison, WI 53715, USA
| | - Joshua J Coon
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA; Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Michael Trauner
- Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - David J Pagliarini
- Morgridge Institute for Research, Madison, WI 53715, USA; Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Johan Auwerx
- Laboratory of Integrative and Systems Physiology, École Polytchnique Fédérale de Lausanne, Lausanne 1015, Switzerland.
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822
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Galvan DL, Green NH, Danesh FR. The hallmarks of mitochondrial dysfunction in chronic kidney disease. Kidney Int 2018; 92:1051-1057. [PMID: 28893420 DOI: 10.1016/j.kint.2017.05.034] [Citation(s) in RCA: 295] [Impact Index Per Article: 49.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 05/16/2017] [Accepted: 05/17/2017] [Indexed: 01/12/2023]
Abstract
Recent advances have led to a greater appreciation of how mitochondrial dysfunction contributes to diverse acute and chronic pathologies. Indeed, mitochondria have received increasing attention as a therapeutic target in a variety of diseases because they serve as key regulatory hubs uniquely situated at crossroads between multiple cellular processes. This review provides an overview of the role of mitochondrial dysfunction in chronic kidney disease, with special emphasis on its role in the development of diabetic nephropathy. We examine the current understanding of the molecular mechanisms that cause mitochondrial dysfunction in the kidney and describe the impact of mitochondrial damage on kidney function. The new concept that mitochondrial shape and structure are closely linked with its function in the kidneys is discussed. Furthermore, the mechanisms that translate cellular cues and demands into mitochondrial remodeling and cellular damage, including the role of microRNAs and long noncoding RNAs, are examined with the final goal of identifying mitochondrial targets to improve treatment of patients with chronic kidney diseases.
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Affiliation(s)
- Daniel L Galvan
- Section of Nephrology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Nathanael H Green
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Farhad R Danesh
- Section of Nephrology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA; Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA.
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823
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Li L, Wang C, Yang H, Liu S, Lu Y, Fu P, Liu J. Metabolomics reveal mitochondrial and fatty acid metabolism disorders that contribute to the development of DKD in T2DM patients. MOLECULAR BIOSYSTEMS 2018; 13:2392-2400. [PMID: 28956034 DOI: 10.1039/c7mb00167c] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Diabetic kidney disease (DKD) is the leading cause of ESRD; however, early intervention can greatly prevent the progression of DKD; thus, sensitive biomarkers for DKD are still required. This study was aimed at the identification of potential biomarkers and revelation of underlying pathways in DKD patients by non-targeted metabolomics. Gas chromatography-mass spectrometry was used to analyze urine obtained from the control and type 2 diabetes mellitus (T2DM) and DKD patients, and the renal histological changes in DKD patients were assessed. The DKD group showed increased level of uric acid, 1,5-anhydroglucitol, hippuric acid, stearic acid, and palmitic acid and reduced level of uracil, glycine, aconitic acid, isocitric acid, 4-hydroxybutyrate, 2-deoxyerythritol, and glycolic acid as compared to the control and T2DM groups. Further analysis indicated that many of the changed metabolites were involved in mitochondrial and fatty acid (FA) metabolism, and combined mitochondrial and FA metabolites showed better diagnosis values for DKD. Histological results confirmed that renal expression of key proteins was reduced in DKD patients with respect to mitochondrial biogenesis (PGC-1α, p-AMPK) and FA oxidation (PPAR-α, CPT-1) as compared to that in the control and T2DM groups. This study highlighted that both mitochondrial and FA metabolism were disturbed in DKD, and thus, they could serve as combined biomarkers for the prediction of DKD.
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Affiliation(s)
- Ling Li
- Kidney Research Institute, Division of Nephrology, West China Hospital of Sichuan University, Chengdu, China.
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824
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Qiu C, Hanson RL, Fufaa G, Kobes S, Gluck C, Huang J, Chen Y, Raj D, Nelson RG, Knowler WC, Susztak K. Cytosine methylation predicts renal function decline in American Indians. Kidney Int 2018; 93:1417-1431. [PMID: 29709239 PMCID: PMC5973533 DOI: 10.1016/j.kint.2018.01.036] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 01/07/2018] [Accepted: 01/25/2018] [Indexed: 12/18/2022]
Abstract
Diabetic nephropathy accounts for most of the excess mortality in individuals with diabetes, but the molecular mechanisms by which nephropathy develops are largely unknown. Here we tested cytosine methylation levels at 397,063 genomic CpG sites for association with decline in the estimated glomerular filtration rate (eGFR) over a six year period in 181 diabetic Pima Indians. Methylation levels at 77 sites showed significant association with eGFR decline after correction for multiple comparisons. A model including methylation level at two probes (cg25799291 and cg22253401) improved prediction of eGFR decline in addition to baseline eGFR and the albumin to creatinine ratio with the percent of variance explained significantly improving from 23.1% to 42.2%. Cg22253401 was also significantly associated with eGFR decline in a case-control study derived from the Chronic Renal Insufficiency Cohort. Probes at which methylation significantly associated with eGFR decline were localized to gene regulatory regions and enriched for genes with metabolic functions and apoptosis. Three of the 77 probes that were associated with eGFR decline in blood samples showed directionally consistent and significant association with fibrosis in microdissected human kidney tissue, after correction for multiple comparisons. Thus, cytosine methylation levels may provide biomarkers of disease progression in diabetic nephropathy and epigenetic variations contribute to the development of diabetic kidney disease.
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MESH Headings
- Adult
- Aged
- Albuminuria/ethnology
- Albuminuria/genetics
- Albuminuria/physiopathology
- Apoptosis/genetics
- Case-Control Studies
- Cell Cycle/genetics
- CpG Islands
- Cytosine
- DNA Methylation
- Diabetic Nephropathies/diagnosis
- Diabetic Nephropathies/ethnology
- Diabetic Nephropathies/genetics
- Diabetic Nephropathies/physiopathology
- Disease Progression
- Energy Metabolism/genetics
- Epigenesis, Genetic
- Female
- Fibrosis
- Genetic Predisposition to Disease
- Glomerular Filtration Rate/genetics
- Humans
- Indians, North American/genetics
- Kidney/pathology
- Kidney/physiopathology
- Kidney Failure, Chronic/diagnosis
- Kidney Failure, Chronic/ethnology
- Kidney Failure, Chronic/genetics
- Kidney Failure, Chronic/physiopathology
- Male
- Middle Aged
- Phenotype
- Prognosis
- Renal Insufficiency, Chronic/diagnosis
- Renal Insufficiency, Chronic/ethnology
- Renal Insufficiency, Chronic/genetics
- Renal Insufficiency, Chronic/physiopathology
- Risk Factors
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Affiliation(s)
- Chengxiang Qiu
- Renal, Electrolyte, and Hypertension Division, Department of Medicine, Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Robert L Hanson
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, Arizona, USA.
| | - Gudeta Fufaa
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, Arizona, USA
| | - Sayuko Kobes
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, Arizona, USA
| | - Caroline Gluck
- Renal, Electrolyte, and Hypertension Division, Department of Medicine, Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Jing Huang
- Department of Biostatistics, Epidemiology and Informatics, Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Yong Chen
- Department of Biostatistics, Epidemiology and Informatics, Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Dominic Raj
- Division of Renal Diseases and Hypertension, The George Washington School of Medicine, Washington, DC, USA
| | - Robert G Nelson
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, Arizona, USA
| | - William C Knowler
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, Arizona, USA
| | - Katalin Susztak
- Renal, Electrolyte, and Hypertension Division, Department of Medicine, Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
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825
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Lemos DR, McMurdo M, Karaca G, Wilflingseder J, Leaf IA, Gupta N, Miyoshi T, Susa K, Johnson BG, Soliman K, Wang G, Morizane R, Bonventre JV, Duffield JS. Interleukin-1 β Activates a MYC-Dependent Metabolic Switch in Kidney Stromal Cells Necessary for Progressive Tubulointerstitial Fibrosis. J Am Soc Nephrol 2018; 29:1690-1705. [PMID: 29739813 PMCID: PMC6054344 DOI: 10.1681/asn.2017121283] [Citation(s) in RCA: 148] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 03/27/2018] [Indexed: 12/27/2022] Open
Abstract
Background Kidney injury is characterized by persisting inflammation and fibrosis, yet mechanisms by which inflammatory signals drive fibrogenesis remain poorly defined.Methods RNA sequencing of fibrotic kidneys from patients with CKD identified a metabolic gene signature comprising loss of mitochondrial and oxidative phosphorylation gene expression with a concomitant increase in regulators and enzymes of glycolysis under the control of PGC1α and MYC transcription factors, respectively. We modeled this metabolic switch in vivo, in experimental murine models of kidney injury, and in vitro in human kidney stromal cells (SCs) and human kidney organoids.Results In mice, MYC and the target genes thereof became activated in resident SCs early after kidney injury, suggesting that acute innate immune signals regulate this transcriptional switch. In vitro, stimulation of purified human kidney SCs and human kidney organoids with IL-1β recapitulated the molecular events observed in vivo, inducing functional metabolic derangement characterized by increased MYC-dependent glycolysis, the latter proving necessary to drive proliferation and matrix production. MYC interacted directly with sequestosome 1/p62, which is involved in proteasomal degradation, and modulation of p62 expression caused inverse effects on MYC expression. IL-1β stimulated autophagy flux, causing degradation of p62 and accumulation of MYC. Inhibition of the IL-1R signal transducer kinase IRAK4 in vivo or inhibition of MYC in vivo as well as in human kidney organoids in vitro abrogated fibrosis and reduced tubular injury.Conclusions Our findings define a connection between IL-1β and metabolic switch in fibrosis initiation and progression and highlight IL-1β and MYC as potential therapeutic targets in tubulointerstitial diseases.
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Affiliation(s)
- Dario R Lemos
- Renal Division, Brigham and Women's Hospital, Boston, Massachusetts;
- Harvard Medical School, Boston, Massachusetts
- Research and Development, Biogen, Cambridge, Massachusetts
| | | | - Gamze Karaca
- Research and Development, Biogen, Cambridge, Massachusetts
| | - Julia Wilflingseder
- Renal Division, Brigham and Women's Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
- Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Irina A Leaf
- Research and Development, Biogen, Cambridge, Massachusetts
| | - Navin Gupta
- Renal Division, Brigham and Women's Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Tomoya Miyoshi
- Renal Division, Brigham and Women's Hospital, Boston, Massachusetts
| | - Koichiro Susa
- Renal Division, Brigham and Women's Hospital, Boston, Massachusetts
| | | | - Kirolous Soliman
- Renal Division, Brigham and Women's Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Guanghai Wang
- Renal Division, Brigham and Women's Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
- Department of Occupational Health and Occupational Medicine, School of Public Health, Southern Medical University, Guangzhou, China
| | - Ryuji Morizane
- Renal Division, Brigham and Women's Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Joseph V Bonventre
- Renal Division, Brigham and Women's Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Jeremy S Duffield
- Research and Development, Biogen, Cambridge, Massachusetts
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, Washington; and
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826
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Li Y, Chung S, Li Z, Overstreet JM, Gagnon L, Grouix B, Leduc M, Laurin P, Zhang MZ, Harris RC. Fatty acid receptor modulator PBI-4050 inhibits kidney fibrosis and improves glycemic control. JCI Insight 2018; 3:120365. [PMID: 29769449 DOI: 10.1172/jci.insight.120365] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 04/13/2018] [Indexed: 01/11/2023] Open
Abstract
Extensive kidney fibrosis occurs in several types of chronic kidney diseases. PBI-4050, a potentially novel first-in-class orally active low-molecular weight compound, has antifibrotic and antiinflammatory properties. We examined whether PBI-4050 affected the progression of diabetic nephropathy (DN) in a mouse model of accelerated type 2 diabetes and in a model of selective tubulointerstitial fibrosis. eNOS-/- db/db mice were treated with PBI-4050 from 8-20 weeks of age (early treatment) or from 16-24 weeks of age (late treatment). PBI-4050 treatment ameliorated the fasting hyperglycemia and abnormal glucose tolerance tests seen in vehicle-treated mice. In addition, PBI-4050 preserved (early treatment) or restored (late treatment) blood insulin levels and increased autophagy in islets. PBI-4050 treatment led to significant improvements in lifespan in the diabetic mice. Both early and late PBI-4050 treatment protected against progression of DN, as indicated by reduced histological glomerular injury and albuminuria, slow decline of glomerular filtration rate, and loss of podocytes. PBI-4050 inhibited kidney macrophage infiltration, oxidative stress, and TGF-β-mediated fibrotic signaling pathways, and it also protected against the development of tubulointerstitial fibrosis. To confirm a direct antiinflammatory/antifibrotic effect in the kidney, further studies with a nondiabetic model of EGFR-mediated proximal tubule activation confirmed that PBI-4050 dramatically decreased the development of the associated tubulointerstitial injury and macrophage infiltration. These studies suggest that PBI-4050 attenuates development of DN in type 2 diabetes through improvement of glycemic control and inhibition of renal TGF-β-mediated fibrotic pathways, in association with decreases in macrophage infiltration and oxidative stress.
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Affiliation(s)
- Yan Li
- Division of Nephrology and Hypertension, Department of Medicine, and.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China
| | - Sungjin Chung
- Division of Nephrology and Hypertension, Department of Medicine, and.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Zhilian Li
- Division of Nephrology and Hypertension, Department of Medicine, and.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Jessica M Overstreet
- Division of Nephrology and Hypertension, Department of Medicine, and.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Lyne Gagnon
- Prometic BioSciences Inc., Laval, Quebec, Canada
| | | | - Martin Leduc
- Prometic BioSciences Inc., Laval, Quebec, Canada
| | | | - Ming-Zhi Zhang
- Division of Nephrology and Hypertension, Department of Medicine, and.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Raymond C Harris
- Division of Nephrology and Hypertension, Department of Medicine, and.,Vanderbilt Center for Kidney Disease, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Department of Veterans Affairs, Nashville, Tennessee, USA
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827
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Liu XJ, Wu XY, Wang H, Wang SX, Kong W, Zhang L, Liu G, Huang W. Renal injury in Seipin-deficient lipodystrophic mice and its reversal by adipose tissue transplantation or leptin administration alone: adipose tissue-kidney crosstalk. FASEB J 2018; 32:5550-5562. [PMID: 29738274 DOI: 10.1096/fj.201701427r] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Seipin deficiency is responsible for type 2 congenital generalized lipodystrophy with severe loss of adipose tissue (AT) and could lead to renal failure in humans. However, the effect of Seipin on renal function is poorly understood. Here we report that Seipin knockout (SKO) mice exhibited impaired renal function, enlarged glomerular and mesangial surface areas, renal depositions of lipid, and advanced glycation end products. Elevated glycosuria and increased electrolyte excretion were also detected. Relative renal gene expression in fatty acid oxidation and reabsorption pathways were impaired in SKO mice. Elevated glycosuria might be associated with reduced renal glucose transporter 2 levels. To improve renal function, AT transplantation or leptin administration alone was performed. Both treatments effectively ameliorated renal injury by improving all of the parameters that were measured in the kidney. The treatments also rescued insulin resistance and low plasma leptin levels in SKO mice. Our findings demonstrate for the first time that Seipin deficiency induces renal injury, which is closely related to glucolipotoxicity and impaired renal reabsorption in SKO mice, and is primarily caused by the loss of AT and especially the lack of leptin. AT transplantation and leptin administration are two effective treatments for renal injury in Seipin-deficient mice.-Liu, X.-J., Wu, X.-Y., Wang, H., Wang, S.-X., Kong, W., Zhang, L., Liu, G., Huang, W. Renal injury in Seipin-deficient lipodystrophic mice and its reversal by adipose tissue transplantation or leptin administration alone: adipose tissue-kidney crosstalk.
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Affiliation(s)
- Xue-Jing Liu
- Institute of Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing, China
| | - Xiao-Yue Wu
- Institute of Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing, China
| | - Huan Wang
- Institute of Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing, China
| | - Su-Xia Wang
- Renal Division, Department of Medicine, Peking University First Hospital, Ministry of Health of China, Beijing, China.,Institute of Nephrology, Peking University, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China
| | - Wei Kong
- Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing, China.,Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Ling Zhang
- Institute of Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing, China
| | - George Liu
- Institute of Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing, China
| | - Wei Huang
- Institute of Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing, China
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828
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Genomic integration of ERRγ-HNF1β regulates renal bioenergetics and prevents chronic kidney disease. Proc Natl Acad Sci U S A 2018; 115:E4910-E4919. [PMID: 29735694 DOI: 10.1073/pnas.1804965115] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mitochondrial dysfunction is increasingly recognized as a critical determinant of both hereditary and acquired kidney diseases. However, it remains poorly understood how mitochondrial metabolism is regulated to support normal kidney function and how its dysregulation contributes to kidney disease. Here, we show that the nuclear receptor estrogen-related receptor gamma (ERRγ) and hepatocyte nuclear factor 1 beta (HNF1β) link renal mitochondrial and reabsorptive functions through coordinated epigenomic programs. ERRγ directly regulates mitochondrial metabolism but cooperatively controls renal reabsorption via convergent binding with HNF1β. Deletion of ERRγ in renal epithelial cells (RECs), in which it is highly and specifically expressed, results in severe renal energetic and reabsorptive dysfunction and progressive renal failure that recapitulates phenotypes of animals and patients with HNF1β loss-of-function gene mutations. Moreover, ERRγ expression positively correlates with renal function and is decreased in patients with chronic kidney disease (CKD). REC-ERRγ KO mice share highly overlapping renal transcriptional signatures with human patients with CKD. Together these findings reveal a role for ERRγ in directing independent and HNF1β-integrated programs for energy production and use essential for normal renal function and the prevention of kidney disease.
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829
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Siempos II, Ma KC, Imamura M, Baron RM, Fredenburgh LE, Huh JW, Moon JS, Finkelsztein EJ, Jones DS, Lizardi MT, Schenck EJ, Ryter SW, Nakahira K, Choi AM. RIPK3 mediates pathogenesis of experimental ventilator-induced lung injury. JCI Insight 2018; 3:97102. [PMID: 29720570 DOI: 10.1172/jci.insight.97102] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 04/04/2018] [Indexed: 12/18/2022] Open
Abstract
In patients requiring ventilator support, mechanical ventilation (MV) may induce acute lung injury (ventilator-induced lung injury [VILI]). VILI is associated with substantial morbidity and mortality in mechanically ventilated patients with and without acute respiratory distress syndrome. At the cellular level, VILI induces necrotic cell death. However, the contribution of necroptosis, a programmed form of necrotic cell death regulated by receptor-interacting protein-3 kinase (RIPK3) and mixed-lineage kinase domain-like pseudokinase (MLKL), to the development of VILI remains unexplored. Here, we show that plasma levels of RIPK3, but not MLKL, were higher in patients with MV (i.e., those prone to VILI) than in patients without MV (i.e., those less likely to have VILI) in two large intensive care unit cohorts. In mice, RIPK3 deficiency, but not MLKL deficiency, ameliorated VILI. In both humans and mice, VILI was associated with impaired fatty acid oxidation (FAO), but in mice this association was not observed under conditions of RIPK3 deficiency. These findings suggest that FAO-dependent RIPK3 mediates pathogenesis of acute lung injury.
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Affiliation(s)
- Ilias I Siempos
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, New York-Presbyterian Hospital/Weill Cornell Medical Center, Weill Cornell Medicine (WCM), New York, New York, USA.,First Department of Critical Care Medicine and Pulmonary Services, Evangelismos Hospital, University of Athens Medical School, Athens, Greece
| | - Kevin C Ma
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, New York-Presbyterian Hospital/Weill Cornell Medical Center, Weill Cornell Medicine (WCM), New York, New York, USA
| | - Mitsuru Imamura
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, New York-Presbyterian Hospital/Weill Cornell Medical Center, Weill Cornell Medicine (WCM), New York, New York, USA
| | - Rebecca M Baron
- Division of Pulmonary and Critical Medicine, Brigham and Women's Hospital (BWH), Harvard Medical School, Boston, Massachusetts, USA
| | - Laura E Fredenburgh
- Division of Pulmonary and Critical Medicine, Brigham and Women's Hospital (BWH), Harvard Medical School, Boston, Massachusetts, USA
| | - Jin-Won Huh
- Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Jong-Seok Moon
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, New York-Presbyterian Hospital/Weill Cornell Medical Center, Weill Cornell Medicine (WCM), New York, New York, USA
| | - Eli J Finkelsztein
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, New York-Presbyterian Hospital/Weill Cornell Medical Center, Weill Cornell Medicine (WCM), New York, New York, USA
| | - Daniel S Jones
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, New York-Presbyterian Hospital/Weill Cornell Medical Center, Weill Cornell Medicine (WCM), New York, New York, USA
| | - Michael Torres Lizardi
- Department of Medicine, New York-Presbyterian Hospital/Weill Cornell Medical Center, WCM, New York, New York, USA
| | - Edward J Schenck
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, New York-Presbyterian Hospital/Weill Cornell Medical Center, Weill Cornell Medicine (WCM), New York, New York, USA
| | - Stefan W Ryter
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, New York-Presbyterian Hospital/Weill Cornell Medical Center, Weill Cornell Medicine (WCM), New York, New York, USA
| | - Kiichi Nakahira
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, New York-Presbyterian Hospital/Weill Cornell Medical Center, Weill Cornell Medicine (WCM), New York, New York, USA
| | - Augustine Mk Choi
- Department of Medicine, New York-Presbyterian Hospital/Weill Cornell Medical Center, WCM, New York, New York, USA
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830
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Abstract
PURPOSE OF REVIEW Sepsis is a common and frequently fatal condition in which mortality has been consistently linked to increasing organ dysfunction. For example, acute kidney injury (AKI) occurs in 40-50% of septic patients and increases mortality six to eight-fold. However, the mechanisms by which sepsis causes organ dysfunction are not well understood and hence current therapy remains reactive and nonspecific. RECENT FINDINGS Recent studies have challenged the previous notion that organ dysfunction is solely secondary to hypoperfusion, by showing, for example, that AKI occurs in the setting of normal or increased renal blood flow; and that it is characterized not by acute tubular necrosis or apoptosis, but rather by heterogeneous areas of colocalized sluggish peritubular blood flow and tubular epithelial cell oxidative stress. Evidence has also shown that microvascular dysfunction, inflammation, and the metabolic response to inflammatory injury are fundamental pathophysiologic mechanisms that may explain the development of sepsis-induced AKI. SUMMARY The implications of these findings are significant because in the context of decades of negative clinical trials in the field, the recognition that other mechanisms are at play opens the possibility to better understand the processes of injury and repair, and provides an invaluable opportunity to design mechanism-targeted therapeutic interventions.
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831
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Lovisa S, Kalluri R. Fatty Acid Oxidation Regulates the Activation of Endothelial-to-Mesenchymal Transition. Trends Mol Med 2018; 24:432-434. [DOI: 10.1016/j.molmed.2018.03.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 03/07/2018] [Indexed: 12/21/2022]
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832
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Heo JY, Kim JE, Dan Y, Kim YW, Kim JY, Cho KH, Bae YK, Im SS, Liu KH, Song IH, Kim JR, Lee IK, Park SY. Clusterin deficiency induces lipid accumulation and tissue damage in kidney. J Endocrinol 2018; 237:175-191. [PMID: 29563234 DOI: 10.1530/joe-17-0453] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 03/21/2018] [Indexed: 01/15/2023]
Abstract
Clusterin is a secretory glycoprotein that is involved in multiple physiopathological processes, including lipid metabolism. Previous studies have shown that clusterin prevents hepatic lipid accumulation via suppression of sterol regulatory element-binding protein (SREBP) 1. In this study, we examined the role of clusterin in renal lipid accumulation in clusterin-knockout mice and NRK52e tubular epithelial cells. Clusterin deficiency increased the expression of SREBP1 and its target genes and decreased malonyl-CoA decarboxylase protein levels in the kidney. Expression of the endocytic receptor, megalin, and scavenger receptor class A was increased in clusterin-deficient mice. Functional analysis of lipid metabolism also revealed that lipid uptake and triglyceride synthesis were increased and fatty acid oxidation was reduced, leading to increased lipid accumulation in clusterin-deficient mice. These phenomena were accompanied by mesangial expansion, fibrosis and increased urinary protein-to-creatinine ratio. High-fat feeding aggravated these clusterin deficiency-induced pathological changes. Clusterin knockdown in NRK52e cells increased lipogenic gene expression and lipid levels, whereas overexpression of clusterin by treatment with adenovirus or recombinant clusterin protein suppressed lipogenic gene expression and lipid levels. Transforming growth factor-beta 1 (TGFB1) expression increased in the kidney of clusterin-deficient mice and suppression of TGFB1 in NRK52e cells suppressed lipid accumulation. These results suggest that clusterin deficiency induces renal lipid accumulation by dysregulating the expression of lipid metabolism-related factors and TGFB1, thereby leading to chronic kidney disease. Hence, clusterin may serve as a therapeutic target for lipid-induced chronic kidney disease.
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Affiliation(s)
- Jung-Yoon Heo
- Department of PhysiologyCollege of Medicine, Yeungnam University, Daegu, Korea
- Smart-Aging Convergence Research CenterCollege of Medicine, Yeungnam University, Daegu, Korea
| | - Ji-Eun Kim
- Department of PhysiologyCollege of Medicine, Yeungnam University, Daegu, Korea
- Smart-Aging Convergence Research CenterCollege of Medicine, Yeungnam University, Daegu, Korea
| | - Yongwook Dan
- Weinberg CollegeNorthwestern University, Evanston, Illinois, USA
| | - Yong-Woon Kim
- Department of PhysiologyCollege of Medicine, Yeungnam University, Daegu, Korea
| | - Jong-Yeon Kim
- Department of PhysiologyCollege of Medicine, Yeungnam University, Daegu, Korea
| | - Kyu Hyang Cho
- Department of Internal MedicineCollege of Medicine, Yeungnam University, Daegu, Korea
| | - Young Kyung Bae
- Department of PathologyCollege of Medicine, Yeungnam University, Daegu, Korea
| | - Seung-Soon Im
- Department of PhysiologyKeimyung University School of Medicine, Daegu, Korea
| | - Kwang-Hyeon Liu
- College of Pharmacy and Research Institute of Pharmaceutical SciencesKyungpook National University, Daegu, Korea
| | - In-Hwan Song
- Department of AnatomyCollege of Medicine, Yeungnam University, Daegu, Korea
| | - Jae-Ryong Kim
- Smart-Aging Convergence Research CenterCollege of Medicine, Yeungnam University, Daegu, Korea
- Department of Biochemistry and Molecular BiologyCollege of Medicine, Yeungnam University, Daegu, Korea
| | - In-Kyu Lee
- Department of Internal MedicineSchool of Medicine, Kyungpook National University, Daegu, Korea
| | - So-Young Park
- Department of PhysiologyCollege of Medicine, Yeungnam University, Daegu, Korea
- Smart-Aging Convergence Research CenterCollege of Medicine, Yeungnam University, Daegu, Korea
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833
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Qiao X, Wang L, Wang Y, Su X, Qi Y, Fan Y, Peng Z. Intermedin inhibits unilateral ureteral obstruction-induced oxidative stress via NADPH oxidase Nox4 and cAMP-dependent mechanisms. Ren Fail 2018; 39:652-659. [PMID: 28805491 PMCID: PMC6447914 DOI: 10.1080/0886022x.2017.1361839] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
NADPH oxidase Nox4-derived reactive oxygen species (ROS) play important roles in renal fibrosis. Our previous study demonstrated that intermedin (IMD) alleviated unilateral ureteral obstruction (UUO)-induced renal fibrosis by inhibition of ROS. However, the precise mechanisms remain unclear. Herein, we investigated the effect of IMD on Nox4 expression and NADPH oxidase activity in rat UUO model, and explored if these effect were achieved through cAMP-PKA pathway, the important post-receptor signal transduction pathway of IMD, in TGF-β1-stimulated rat proximal tubular cell (NRK-52E). Renal fibrosis was induced by UUO. NRK-52E was exposed to rhTGF-β1 to establish an in vitro model of fibrosis. IMD was overexpressed in the kidney and in NRK-52E by IMD gene transfer. We studied UUO-induced ROS by measuring dihydroethidium levels and lipid peroxidation end-product 4-hydroxynonenal expression. Nox4 expression in the obstructed kidney of UUO rat or in TGF-β1-stimulated NRK-52E was measured by quantitative RT-PCR and Western blotting. We analyzed NADPH oxidase activity using a lucigenin-enhanced chemiluminescence system. We showed that UUO-stimulated ROS production was remarkably attenuated by IMD gene transfer. IMD overexpression inhibited UUO-induced up-regulation of Nox4 and activation of NADPH oxidase. Consistent with in vivo results, TGF-β1-stimulated increase in Nox4 expression and NADPH oxidase activity was blocked by IMD. In NRK-52E, these beneficial effects of IMD were abolished by pretreatment with N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide hydrochloride (H-89), a PKA inhibitor, and mimicked by a cell-permeable cAMP analog dibutyl-cAMP. Our results indicate that IMD exerts anti-oxidant effects by inhibition of Nox4, and the effect can be mediated by cAMP-PKA pathway.
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Affiliation(s)
- Xi Qiao
- a Department of Nephrology , Second Hospital of Shanxi Medical University , Shanxi , China.,b Shanxi Kidney Disease Institute , Shanxi , China
| | - Lihua Wang
- a Department of Nephrology , Second Hospital of Shanxi Medical University , Shanxi , China.,b Shanxi Kidney Disease Institute , Shanxi , China
| | - Yanhong Wang
- c Department of Microbiology and Immunology , Shanxi Medical University , Taiyuan , Shanxi , China
| | - Xiaole Su
- a Department of Nephrology , Second Hospital of Shanxi Medical University , Shanxi , China.,b Shanxi Kidney Disease Institute , Shanxi , China
| | - Yue Qi
- a Department of Nephrology , Second Hospital of Shanxi Medical University , Shanxi , China.,b Shanxi Kidney Disease Institute , Shanxi , China
| | - Yun Fan
- a Department of Nephrology , Second Hospital of Shanxi Medical University , Shanxi , China.,b Shanxi Kidney Disease Institute , Shanxi , China
| | - Zhiqiang Peng
- a Department of Nephrology , Second Hospital of Shanxi Medical University , Shanxi , China.,b Shanxi Kidney Disease Institute , Shanxi , China
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834
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Simon-Tillaux N, Hertig A. Snail and kidney fibrosis. Nephrol Dial Transplant 2018; 32:224-233. [PMID: 28186539 DOI: 10.1093/ndt/gfw333] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 08/04/2016] [Indexed: 12/13/2022] Open
Abstract
Snail family zinc finger 1 (SNAI1) is a transcription factor expressed during renal embryogenesis, and re-expressed in various settings of acute kidney injury (AKI). Subjected to tight regulation, SNAI1 controls major biological processes responsible for renal fibrogenesis, including mesenchymal reprogramming of tubular epithelial cells, shutdown of fatty acid metabolism, cell cycle arrest and inflammation of the microenvironment surrounding tubular epithelial cells. The present review describes in detail the interactions of SNAI1 with AKI-associated signalling pathways. We also discuss how this central factor has been iteratively (and promisingly) targeted in a number of animal models in order to prevent or slow down renal fibrogenesis.
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Affiliation(s)
- Noémie Simon-Tillaux
- French National Institute of Health and Medical Research (INSERM), UMR_S1155, Remodeling and Repair of Renal Tissue, Hôpital Tenon, Paris, France
| | - Alexandre Hertig
- French National Institute of Health and Medical Research (INSERM), UMR_S1155, Remodeling and Repair of Renal Tissue, Hôpital Tenon, Paris, France.,Sorbonne Universités, UPMC Paris 06, UMR S_1155, Paris, France
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835
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Villie P, Dommergues M, Brocheriou I, Piccoli GB, Tourret J, Hertig A. Why kidneys fail post-partum: a tubulocentric viewpoint. J Nephrol 2018; 31:645-651. [PMID: 29637465 DOI: 10.1007/s40620-018-0488-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 03/30/2018] [Indexed: 12/20/2022]
Abstract
Kidneys may fail post-partum in a number of circumstances due, for example, to post-partum haemorrhage, preeclampsia, amniotic fluid embolism or septic abortion. All these conditions in pregnancy and post partum represent a threat not only to the endothelium but also to the renal tubular epithelium, and as such may lead to rapid and also irreversible impairment of the renal function. This paper is a non-systematic review of the literature and of our experience, in which we discuss the main open issues on kidney disease in pregnancy and following delivery, in particular as regards tubular damage, with the aim to help reasoning on acute kidney injury (AKI) following delivery. The review will emphasize the often under-estimated importance of the tubular epithelium in the peri-partum period and will: (1) describe the main characteristics of the renal tissues around delivery; (2) define pregnancy-related AKI according to recent Kidney Disease/Improving Global Outcome (KDIGO) guidelines; (3) discuss the most common circumstances of post-partum AKI; and (4) describe the input expected from urinalysis, renal imaging and kidney biopsy.
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Affiliation(s)
- Patricia Villie
- APHP, Hôpital Tenon, Urgences Néphrologiques et Transplantation Rénale, 4 rue de la Chine, 75020, Paris, France
| | - Marc Dommergues
- Department of Gynecology and Obstetrics, APHP, Groupe Hospitalier La Pitié Salpêtrière Charles Foix, Paris, France
| | - Isabelle Brocheriou
- Department of Pathology, APHP, Hôpital Tenon, Paris, France.,Sorbonne Universités, UPMC Université Paris 06, UMR_S 1155, 75005, Paris, France
| | - Giorgina Barbara Piccoli
- Centre Hospitalier du Mans Le Mans, Le Mans, France.,Department of Clinical and Biological Sciences, University of Torino, Turin, Italy
| | - Jérôme Tourret
- Sorbonne Universités, UPMC Université Paris 06, UMR_S 1155, 75005, Paris, France
| | - Alexandre Hertig
- APHP, Hôpital Tenon, Urgences Néphrologiques et Transplantation Rénale, 4 rue de la Chine, 75020, Paris, France. .,Sorbonne Universités, UPMC Université Paris 06, UMR_S 1155, 75005, Paris, France.
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836
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Park J, Shrestha R, Qiu C, Kondo A, Huang S, Werth M, Li M, Barasch J, Suszták K. Single-cell transcriptomics of the mouse kidney reveals potential cellular targets of kidney disease. Science 2018; 360:758-763. [PMID: 29622724 DOI: 10.1126/science.aar2131] [Citation(s) in RCA: 696] [Impact Index Per Article: 116.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 03/27/2018] [Indexed: 12/12/2022]
Abstract
Our understanding of kidney disease pathogenesis is limited by an incomplete molecular characterization of the cell types responsible for the organ's multiple homeostatic functions. To help fill this knowledge gap, we characterized 57,979 cells from healthy mouse kidneys by using unbiased single-cell RNA sequencing. On the basis of gene expression patterns, we infer that inherited kidney diseases that arise from distinct genetic mutations but share the same phenotypic manifestation originate from the same differentiated cell type. We also found that the collecting duct in kidneys of adult mice generates a spectrum of cell types through a newly identified transitional cell. Computational cell trajectory analysis and in vivo lineage tracing revealed that intercalated cells and principal cells undergo transitions mediated by the Notch signaling pathway. In mouse and human kidney disease, these transitions were shifted toward a principal cell fate and were associated with metabolic acidosis.
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Affiliation(s)
- Jihwan Park
- Renal Electrolyte and Hypertension Division, Department of Medicine and Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Rojesh Shrestha
- Renal Electrolyte and Hypertension Division, Department of Medicine and Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Chengxiang Qiu
- Renal Electrolyte and Hypertension Division, Department of Medicine and Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ayano Kondo
- Renal Electrolyte and Hypertension Division, Department of Medicine and Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shizheng Huang
- Renal Electrolyte and Hypertension Division, Department of Medicine and Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Max Werth
- Renal Division, Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Mingyao Li
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jonathan Barasch
- Renal Division, Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Katalin Suszták
- Renal Electrolyte and Hypertension Division, Department of Medicine and Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA.
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837
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Adeosun SO, Gordon DM, Weeks MF, Moore KH, Hall JE, Hinds TD, Stec DE. Loss of biliverdin reductase-A promotes lipid accumulation and lipotoxicity in mouse proximal tubule cells. Am J Physiol Renal Physiol 2018; 315:F323-F331. [PMID: 29631357 DOI: 10.1152/ajprenal.00495.2017] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Obesity and increased lipid availability have been implicated in the development and progression of chronic kidney disease. One of the major sites of renal lipid accumulation is in the proximal tubule cells of the kidney, suggesting that these cells may be susceptible to lipotoxicity. We previously demonstrated that loss of hepatic biliverdin reductase A (BVRA) causes fat accumulation in livers of mice on a high-fat diet. To determine the role of BVRA in mouse proximal tubule cells, we generated a CRISPR targeting BVRA for a knockout in mouse proximal tubule cells (BVRA KO). The BVRA KO cells had significantly less metabolic potential and mitochondrial respiration, which was exacerbated by treatment with palmitic acid, a saturated fatty acid. The BVRA KO cells also showed increased intracellular triglycerides which were associated with higher fatty acid uptake gene cluster of differentiation 36 as well as increased de novo lipogenesis as measured by higher neutral lipids. Additionally, neutrophil gelatinase-associated lipocalin 1 expression, annexin-V FITC staining, and lactate dehydrogenase assays all demonstrated that BVRA KO cells are more sensitive to palmitic acid-induced lipotoxicity than wild-type cells. Phosphorylation of BAD which plays a role in cell survival pathways, was significantly reduced in palmitic acid-treated BVRA KO cells. These data demonstrate the protective role of BVRA in proximal tubule cells against saturated fatty acid-induced lipotoxicity and suggest that activating BVRA could provide a benefit in protecting from obesity-induced kidney injury.
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Affiliation(s)
- Samuel O Adeosun
- Department of Physiology & Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
| | - Darren M Gordon
- Department of Physiology and Pharmacology, University of Toledo College of Medicine , Toledo, Ohio
| | - Mary Frances Weeks
- Department of Physiology & Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
| | - Kyle H Moore
- Department of Physiology & Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
| | - John E Hall
- Department of Physiology & Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
| | - Terry D Hinds
- Department of Physiology and Pharmacology, University of Toledo College of Medicine , Toledo, Ohio
| | - David E Stec
- Department of Physiology & Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
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838
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Su H, Wan C, Lei CT, Zhang CY, Ye C, Tang H, Qiu Y, Zhang C. Lipid Deposition in Kidney Diseases: Interplay Among Redox, Lipid Mediators, and Renal Impairment. Antioxid Redox Signal 2018; 28:1027-1043. [PMID: 28325081 DOI: 10.1089/ars.2017.7066] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Significance: The relationship between lipid disturbances and renal diseases has been studied for several decades, and it is well recognized that when the balance of renal lipid uptake, synthesis, oxidation, and outflow is disrupted, lipids will undergo oxidation, be sequestrated as lipid droplets, generate toxic metabolites, and cause nephrotoxicity in diverse renal diseases. Recent Advances: During renal disorders, redox signaling is a pivotal event promoting or resulting from lipid disorders. Accordingly, a vicious cycle of lipid redox dysregulation could be developed, accelerating the renal damage. Critical Issues: The aim of this concise review is to introduce the connection among redox, lipid abnormalities and kidney damage in various conditions. And we summarized current understanding of the lipid redox loop implicated in acute kidney injury, chronic kidney disease, metabolic abnormalities, aging, and genetic pitfalls. Future Directions: Despite recent advances, further investigations are required to clarify the complicated molecular and regulatory mechanisms among redox, lipid mediators and renal disorders. Moreover, exploring an ideal target for potential therapies should be discussed and studied in future. Antioxid. Redox Signal. 28, 1027-1043.
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Affiliation(s)
- Hua Su
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Cheng Wan
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chun-Tao Lei
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chun-Yun Zhang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chen Ye
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hui Tang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yue Qiu
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chun Zhang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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839
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Jung JH, Choi JE, Song JH, Ahn SH. Human CD36 overexpression in renal tubules accelerates the progression of renal diseases in a mouse model of folic acid-induced acute kidney injury. Kidney Res Clin Pract 2018; 37:30-40. [PMID: 29629275 PMCID: PMC5875574 DOI: 10.23876/j.krcp.2018.37.1.30] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 01/29/2018] [Accepted: 01/30/2018] [Indexed: 11/04/2022] Open
Abstract
Background Acute kidney injury (AKI) is a risk factor for progression to chronic kidney disease, with even subclinical AKI episodes progressing to chronic kidney disease. Several risk factors such as preexisting kidney disease, hyperglycemia, and hypertension may aggravate renal disease after AKI. However, mechanisms underlying the progression of AKI are still unclear. This study identified the effect of human cluster of differentiation 36 (CD36) overexpression on the progression of folic acid-induced AKI. Methods Pax8-rtTA/tetracycline response element-human CD36 transgenic mice were used to elucidate the effect of human CD36 overexpression in the proximal tubules on folic acid-induced AKI. Results Results of histological analysis showed severely dilated tubules with casts and albuminuria in folic acid-treated transgenic mice overexpressing human CD36 compared with folic acid-treated wild-type mice. In addition, analysis of mRNA expression showed a significant increase in the collagen 3a1 gene in folic acid-treated transgenic mice overexpressing human CD 36 compared with folic acid-treated wild type mice. Conclusion Human CD36-overexpressing transgenic mice showed severe pathological changes and albuminuria compared with wild-type mice. Moreover, mRNA expression of the collagen 3a1 gene increased in folic acid-treated transgenic mice. These results suggest that human CD36 overexpression is a risk factor of AKI and its progression to chronic kidney disease.
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Affiliation(s)
- Jong Hwan Jung
- Division of Nephrology, Department of Internal Medicine, Wonkwang University School of Medicine, Iksan, Korea
| | - Jee Eun Choi
- Division of Nephrology, Department of Internal Medicine, Wonkwang University School of Medicine, Iksan, Korea
| | - Ju Hung Song
- Division of Nephrology, Department of Internal Medicine, Wonkwang University School of Medicine, Iksan, Korea
| | - Seon-Ho Ahn
- Division of Nephrology, Department of Internal Medicine, Wonkwang University School of Medicine, Iksan, Korea
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840
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Steiger S, Grill JF, Ma Q, Bäuerle T, Jordan J, Smolle M, Böhland C, Lech M, Anders HJ. Anti-Transforming Growth Factor β IgG Elicits a Dual Effect on Calcium Oxalate Crystallization and Progressive Nephrocalcinosis-Related Chronic Kidney Disease. Front Immunol 2018; 9:619. [PMID: 29651290 PMCID: PMC5884871 DOI: 10.3389/fimmu.2018.00619] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 03/12/2018] [Indexed: 11/13/2022] Open
Abstract
Crystallopathies are a heterogeneous group of diseases caused by intrinsic or environmental microparticles or crystals, promoting tissue inflammation and scarring. Certain proteins interfere with crystal formation and growth, e.g., with intrarenal calcium oxalate (CaOx) crystal formation, a common cause of kidney stone disease or nephrocalcinosis-related chronic kidney disease (CKD). We hypothesized that immunoglobulins can modulate CaOx microcrystal formation and crystal growth and that therefore, biological IgG-based drugs designed to specifically target disease modifying proteins would elicit a dual effect on the outcome of CaOx-related crystallopathies. Indeed, both the anti-transforming growth factor (TGF)β IgG and control IgG1 antibody impaired CaOx crystallization in vitro, and decreased intrarenal CaOx crystal deposition and subsequent CKD in mice on an oxalate-rich diet compared to oxalate-fed control mice. However, the TGFβ-specific IgG antibody showed nephroprotective effects beyond those of control IgG1 and substantially reduced interstitial fibrosis as indicated by magnetic resonance imaging, silver and α-smooth muscle actin staining, RT-qPCR, and flow cytometry for pro-fibrotic macrophages. Suppressing interstitial fibrosis slowed the decline of glomerular filtration rate (GFR) compared to treatment with control IgG1 [slope of m = −8.9 vs. m = −14.5 μl/min/100 g body weight (BW)/day, Δ = 38.3%], an increased GFR at the end of the study (120.4 vs. 42.6 μl/min/100 g BW, Δ = 64.6%), and prolonged end stage renal disease (ESRD)-free renal survival by 10 days (Δ = 38.5%). Delayed onset of anti-TGFβ IgG from day 7 was no longer effective. Our results suggest that biological drugs can elicit dual therapeutic effects on intrinsic crystallopathies, such as anti-TGFβ IgG antibody treatment inhibits CaOx crystallization as well as interstitial fibrosis in nephrocalcinosis-related CKD.
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Affiliation(s)
- Stefanie Steiger
- Division of Nephrology, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany
| | - Julia Felicitas Grill
- Division of Nephrology, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany
| | - Qiuyue Ma
- Division of Nephrology, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany
| | - Tobias Bäuerle
- Preclinical Imaging Platform Erlangen, Institute of Radiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jutta Jordan
- Preclinical Imaging Platform Erlangen, Institute of Radiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Michaela Smolle
- Ludwig-Maximilians Universität München, Biomedizinisches Centrum, Munich, Germany
| | - Claudia Böhland
- Department of Radiation Oncology, Ludwig-Maximilians Universität München, Munich, Germany
| | - Maciej Lech
- Division of Nephrology, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany
| | - Hans-Joachim Anders
- Division of Nephrology, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany
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841
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Preservation of renal function in chronic diabetes by enhancing glomerular glucose metabolism. J Mol Med (Berl) 2018; 96:373-381. [PMID: 29574544 DOI: 10.1007/s00109-018-1630-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 02/07/2018] [Accepted: 02/12/2018] [Indexed: 12/24/2022]
Abstract
Diabetic nephropathy (DN) affects approximately 30-40% of patients with type 1 (T1DM) and type 2 diabetes (T2DM). It is a major cause of end-stage renal disease (ESRD) for the developed world. Hyperglycemia and genetics are major causal factors for the initiation and progression of DN. Multiple abnormalities in glucose and mitochondrial metabolism induced by diabetes likely contribute to the severity of DN. Recent clinical studies in people with extreme duration of T1DM (> 50 years, Joslin Medalist Study) have supported the importance of endogenous protective factors to neutralize the toxic effects of hyperglycemia on renal and other vascular tissues. Using renal glomeruli from these patients (namely Medalists) with and without DN, we have shown the importance of increased glycolytic flux in decreasing the accumulation of glucose toxic metabolites, improving mitochondrial function, survival of glomerular podocytes, and reducing glomerular pathology. Activation of a key glycolytic enzyme, pyruvate kinase M2 (PKM2), resulted in the normalization of renal hemodynamics and mitochondrial and glomerular dysfunction, leading to the mitigation of glomerular pathologies in several mouse models of DN.
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842
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Ding W, Yousefi K, Goncalves S, Goldstein BJ, Sabater AL, Kloosterboer A, Ritter P, Lambert G, Mendez AJ, Shehadeh LA. Osteopontin deficiency ameliorates Alport pathology by preventing tubular metabolic deficits. JCI Insight 2018; 3:94818. [PMID: 29563333 PMCID: PMC5926939 DOI: 10.1172/jci.insight.94818] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 02/09/2018] [Indexed: 12/31/2022] Open
Abstract
Alport syndrome is a rare hereditary renal disorder with no etiologic therapy. We found that osteopontin (OPN) is highly expressed in the renal tubules of the Alport mouse and plays a causative pathological role. OPN genetic deletion ameliorated albuminuria, hypertension, tubulointerstitial proliferation, renal apoptosis, and hearing and visual deficits in the Alport mouse. In Alport renal tubules we found extensive cholesterol accumulation and increased protein expression of dynamin-3 (DNM3) and LDL receptor (LDLR) in addition to dysmorphic mitochondria with defective bioenergetics. Increased pathological cholesterol influx was confirmed by a remarkably increased uptake of injected DiI-LDL cholesterol by Alport renal tubules, and by the improved lifespan of the Alport mice when crossed with the Ldlr-/- mice with defective cholesterol influx. Moreover, OPN-deficient Alport mice demonstrated significant reduction of DNM3 and LDLR expression. In human renal epithelial cells, overexpressing DNM3 resulted in elevated LDLR protein expression and defective mitochondrial respiration. Our results suggest a potentially new pathway in Alport pathology where tubular OPN causes DNM3- and LDLR-mediated enhanced cholesterol influx and impaired mitochondrial respiration.
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Affiliation(s)
- Wen Ding
- Department of Molecular and Cellular Pharmacology
- Interdisciplinary Stem Cell Institute
| | - Keyvan Yousefi
- Department of Molecular and Cellular Pharmacology
- Interdisciplinary Stem Cell Institute
| | | | | | | | | | | | | | | | - Lina A. Shehadeh
- Interdisciplinary Stem Cell Institute
- Department of Medicine, Division of Cardiology
- Vascular Biology Institute, and
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami Leonard M. Miller School of Medicine, Miami, Florida, USA
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843
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Sun J, Chen X, Liu T, Jiang X, Wu Y, Yang S, Hua W, Li Z, Huang H, Ruan X, Du X. Berberine Protects Against Palmitate-Induced Apoptosis in Tubular Epithelial Cells by Promoting Fatty Acid Oxidation. Med Sci Monit 2018. [PMID: 29528039 PMCID: PMC5859669 DOI: 10.12659/msm.908927] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Increased lipid accumulation in renal tubular epithelial cells (TECs) contributes to their injury and dysfunction and progression of tubulointerstitial fibrosis. Berberine (BBR), a natural plant alkaloid isolated from traditional medicine herbs, is effective in lowing serum lipid, and has a protective effect on chronic kidney disease (CKD) with dyslipidemia, including diabetic nephropathy. The aim of this study was to investigate the effect of BBR on palmitate (PA)-induced lipid accumulation and apoptosis in TECs. MATERIAL AND METHODS Human kidney proximal tubular epithelial cell line (HK-2) cells were treated with PA, BBR, and/or palmitoyltransferase 1A (CPT1A) inhibitor Etomoxir. Intracellular lipid content was assessed by Oil Red O and Nile Red staining. Cell apoptosis rate was evaluated by flow cytometry assay. The expression of apoptosis-related protein cleaved-caspase3 and fatty acid oxidation (FAO)-regulating proteins, including CPT1A, peroxisome proliferator-activated receptor α (PPARα), and PPARγ co-activator-1α (PGC1α), was measured by Western blot analysis and immunofluorescence. RESULTS In the present study, PA treatment increased intracellular lipid deposition accompanied by elevated apoptosis in TECs compared with control group, whereas the protein expression of CPT1A, PPARα, and PGC1α, did not correspondingly increase in TECs. BBR significantly up-regulated the protein expression of CPT1A, PPARα, and PGC1α in TECs treated with or without PA, and reversed PA-induced intracellular lipid accumulation and apoptosis. Moreover, the CPT1A inhibitor Etomoxir counteracted the protective effect of BBR in TECs. CONCLUSIONS These in vitro findings suggest that PA can induce intracellular lipid accumulation and apoptosis in TECs, and the mechanism may be associated with inducing defective FAO, whereas BBR can protect TECs against PA-induced intracellular lipid accumulation and apoptosis by promoting FAO.
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Affiliation(s)
- Jiye Sun
- Department of Nephrology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China (mainland)
| | - Xuemei Chen
- Department of Emergency, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China (mainland)
| | - Ting Liu
- Department of Nephrology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China (mainland)
| | - Xushun Jiang
- Department of Nephrology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China (mainland)
| | - Yue Wu
- Department of Nephrology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China (mainland)
| | - Shan Yang
- Department of Emergency, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China (mainland)
| | - Wei Hua
- Department of Nephrology, Occupational Disease Prevention and Control Hospital of Chongqing, Chongqing, China (mainland)
| | - Zhengdong Li
- Department of Nephrology, Dongfeng Hospital, Hubei University of Medicine, Shiyan, Hubei, China (mainland)
| | - Huizhe Huang
- The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China (mainland)
| | - Xiongzhong Ruan
- Centre for Nephrology, Royal Free and University College Medical School, University College London, Royal Free Campus, London, United Kingdom.,Centre for Lipid Research, Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China (mainland)
| | - Xiaogang Du
- Department of Nephrology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China (mainland).,The Chongqing Key Laboratory of Translational Medicine in Major Metabolic Diseases, Chongqing, China (mainland)
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844
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Qing X, Chinenov Y, Redecha P, Madaio M, Roelofs JJ, Farber G, Issuree PD, Donlin L, Mcllwain DR, Mak TW, Blobel CP, Salmon JE. iRhom2 promotes lupus nephritis through TNF-α and EGFR signaling. J Clin Invest 2018; 128:1397-1412. [PMID: 29369823 DOI: 10.1172/jci97650] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/23/2018] [Indexed: 12/14/2022] Open
Abstract
Lupus nephritis (LN) often results in progressive renal dysfunction. The inactive rhomboid 2 (iRhom2) is a newly identified key regulator of A disintegrin and metalloprotease 17 (ADAM17), whose substrates, such as TNF-α and heparin-binding EGF (HB-EGF), have been implicated in the pathogenesis of chronic kidney diseases. Here, we demonstrate that deficiency of iRhom2 protects the lupus-prone Fcgr2b-/- mice from developing severe kidney damage without altering anti-double-stranded DNA (anti-dsDNA) Ab production by simultaneously blocking HB-EGF/EGFR and TNF-α signaling in the kidney tissues. Unbiased transcriptome profiling of kidneys and kidney macrophages revealed that TNF-α and HB-EGF/EGFR signaling pathways are highly upregulated in Fcgr2b-/- mice, alterations that were diminished in the absence of iRhom2. Pharmacological blockade of either TNF-α or EGFR signaling protected Fcgr2b-/- mice from severe renal damage. Finally, kidneys from LN patients showed increased iRhom2 and HB-EGF expression, with interstitial HB-EGF expression significantly associated with chronicity indices. Our data suggest that activation of iRhom2/ADAM17-dependent TNF-α and EGFR signaling plays a crucial role in mediating irreversible kidney damage in LN, thereby uncovering a target for selective and simultaneous dual inhibition of 2 major pathological pathways in the effector arm of the disease.
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Affiliation(s)
| | - Yurii Chinenov
- Arthritis and Tissue Degeneration Program, Hospital for Special Surgery, New York, New York, USA
| | | | - Michael Madaio
- Department of Medicine, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Joris Jth Roelofs
- Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Gregory Farber
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, New York, USA
| | - Priya D Issuree
- Arthritis and Tissue Degeneration Program, Hospital for Special Surgery, New York, New York, USA
| | - Laura Donlin
- Arthritis and Tissue Degeneration Program, Hospital for Special Surgery, New York, New York, USA
| | - David R Mcllwain
- Baxter Laboratory in Stem Cell Biology, Department of Microbiology and Immunology, Stanford University, Stanford, California, USA
| | - Tak W Mak
- Campbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Center, University Health Network, Toronto, Ontario, Canada
| | - Carl P Blobel
- Arthritis and Tissue Degeneration Program, Hospital for Special Surgery, New York, New York, USA.,Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, New York, USA.,Institute for Advanced Study, Technical University Munich, Munich, Germany.,Department of Medicine, Weill Cornell Medicine, New York, New York, USA
| | - Jane E Salmon
- Program in Inflammation and Autoimmunity, and.,Department of Medicine, Weill Cornell Medicine, New York, New York, USA
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845
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Xiao J, Zhang X, Fu C, Yang Q, Xie Y, Zhang Z, Ye Z. Impaired Na +-K +-ATPase signaling in renal proximal tubule contributes to hyperuricemia-induced renal tubular injury. Exp Mol Med 2018; 50:e452. [PMID: 29497172 PMCID: PMC5898891 DOI: 10.1038/emm.2017.287] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Revised: 09/11/2017] [Accepted: 09/26/2017] [Indexed: 12/27/2022] Open
Abstract
Hyperuricemia contributes to renal inflammation. We aimed to investigate the role of Na+–K+–ATPase (NKA) in hyperuricemia-induced renal tubular injury. Human primary proximal tubular epithelial cells (PTECs) were incubated with uric acid (UA) at increasing doses or for increasing lengths of time. PTECs were then stimulated by pre-incubation with an NKA α1 expression vector or small interfering RNA before UA (100 μg ml−1, 48 h) stimulation. Hyperuricemic rats were induced by gastric oxonic acid and treated with febuxostat (Feb). ATP levels, the activity of NKA and expression of its α1 subunit, Src, NOD-like receptor pyrin domain-containing protein 3 (NLRP3) and interleukin 1β (IL-1β) were measured both in vitro and in vivo. Beginning at concentrations of 100 μg ml−1, UA started to dose-dependently reduce NKA activity. UA at a concentration of 100 μg ml−1 time-dependently affected the NKA activity, with the maximal increased NKA activity at 24 h, but the activity started to decrease after 48 h. This inhibitory effect of UA on NKA activity at 48 h was in addition to a decrease in NKA α1 expression in the cell membrane, but an increase in lysosomes. This process also involved the subsequent activation of Src kinase and NLRP3, promoting IL-1β processing. In hyperuricemic rats, renal cortex NKA activity and its α1 expression were upregulated at the 7th week and both decreased at the 10th week, accompanied with increased renal cortex expression of Src, NLRP3 and IL-1β. The UA levels were reduced and renal tubular injuries in hyperuricemic rats were alleviated in the Feb group. Our data suggested that the impairment of NKA and its consequent regulation of Src, NLRP3 and IL-1β in the renal proximal tubule contributed to hyperuricemia-induced renal tubular injury.
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Affiliation(s)
- Jing Xiao
- Department of Nephrology, Huadong Hospital affiliated with Fudan University, Shanghai, China.,Shanghai Key Laboratory of Clinical Geriatric Medicine, Huadong hospital affiliated with Fudan University, Shanghai, China
| | - Xiaoli Zhang
- Department of Nephrology, Huadong Hospital affiliated with Fudan University, Shanghai, China.,Shanghai Key Laboratory of Clinical Geriatric Medicine, Huadong hospital affiliated with Fudan University, Shanghai, China
| | - Chensheng Fu
- Department of Nephrology, Huadong Hospital affiliated with Fudan University, Shanghai, China.,Shanghai Key Laboratory of Clinical Geriatric Medicine, Huadong hospital affiliated with Fudan University, Shanghai, China
| | - Qingmei Yang
- Department of Nephrology, Huadong Hospital affiliated with Fudan University, Shanghai, China.,Shanghai Key Laboratory of Clinical Geriatric Medicine, Huadong hospital affiliated with Fudan University, Shanghai, China
| | - Ying Xie
- Department of Nephrology, Huadong Hospital affiliated with Fudan University, Shanghai, China.,Shanghai Key Laboratory of Clinical Geriatric Medicine, Huadong hospital affiliated with Fudan University, Shanghai, China
| | - Zhenxing Zhang
- Department of Nephrology, Huadong Hospital affiliated with Fudan University, Shanghai, China.,Shanghai Key Laboratory of Clinical Geriatric Medicine, Huadong hospital affiliated with Fudan University, Shanghai, China
| | - Zhibin Ye
- Department of Nephrology, Huadong Hospital affiliated with Fudan University, Shanghai, China.,Shanghai Key Laboratory of Clinical Geriatric Medicine, Huadong hospital affiliated with Fudan University, Shanghai, China
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846
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Abstract
Diabetic kidney disease (DKD) is the leading cause of morbidity and mortality in diabetic patients. Defining risk factors for DKD using a reductionist approach has proven challenging. Integrative omics-based systems biology tools have shed new insights in our understanding of DKD and have provided several key breakthroughs for identifying novel predictive and diagnostic biomarkers. In this review, we highlight the role of the Warburg effect in DKD and potential regulating factors such as sphingomyelin, fumarate, and pyruvate kinase muscle isozyme M2 in shifting glucose flux from complete oxidation in mitochondria to the glycolytic pathway and its principal branches. With the development of highly sensitive instruments and more advanced automatic bioinformatics tools, we believe that omics analyses and imaging techniques will focus more on singular-cell-level studies, which will allow in-depth understanding of DKD and pave the path for personalized kidney precision medicine.
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Affiliation(s)
- Guanshi Zhang
- Center for Renal Precision Medicine, Division of Nephrology, Department of Medicine, University of Texas Health, San Antonio, TX; Audie L. Murphy Memorial VA Hospital, South Texas Veterans Health Care System, San Antonio, TX
| | - Manjula Darshi
- Center for Renal Precision Medicine, Division of Nephrology, Department of Medicine, University of Texas Health, San Antonio, TX; Audie L. Murphy Memorial VA Hospital, South Texas Veterans Health Care System, San Antonio, TX
| | - Kumar Sharma
- Center for Renal Precision Medicine, Division of Nephrology, Department of Medicine, University of Texas Health, San Antonio, TX; Audie L. Murphy Memorial VA Hospital, South Texas Veterans Health Care System, San Antonio, TX.
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847
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Liu BC, Tang TT, Lv LL, Lan HY. Renal tubule injury: a driving force toward chronic kidney disease. Kidney Int 2018; 93:568-579. [DOI: 10.1016/j.kint.2017.09.033] [Citation(s) in RCA: 260] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 08/17/2017] [Accepted: 09/06/2017] [Indexed: 12/13/2022]
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848
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Sagoo MK, Gnudi L. Diabetic nephropathy: Is there a role for oxidative stress? Free Radic Biol Med 2018; 116:50-63. [PMID: 29305106 DOI: 10.1016/j.freeradbiomed.2017.12.040] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 12/27/2017] [Accepted: 12/31/2017] [Indexed: 01/06/2023]
Abstract
Oxidative stress has been implicated in the pathophysiology of diabetic nephropathy. Studies in experimental animal models of diabetes strongly implicate oxidant species as a major determinant in the pathophysiology of diabetic kidney disease. The translation, in the clinical setting, of these concepts have been quite disappointing, and new theories have challenged the concepts that oxidative stress per se plays a role in the pathophysiology of diabetic kidney disease. The concept of mitochondrial hormesis has been introduced to explain this apparent disconnect. Hormesis is intended as any cellular process that exhibits a biphasic response to exposure to increasing amounts of a substance or condition: specifically, in diabetic kidney disease, oxidant species may represent, at determined concentration, an essential and potentially protective factor. It could be postulated that excessive production or inhibition of oxidant species formation might result in an adverse phenotype. This review discusses the evidence underlying these two apparent contradicting concepts, with the aim to propose and speculate on potential mechanisms underlying the role of oxidant species in the pathophysiology of diabetic nephropathy and possibly open future more efficient therapies to be tested in the clinical settings.
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Affiliation(s)
- Manpreet K Sagoo
- School of Cardiovascular Medicine & Sciences, British Heart Foundation Centre of Research Excellence, Faculty of Life Sciences & Medicine, King's College London, 150 Stamford Street, London SE1 9NH, UK
| | - Luigi Gnudi
- School of Cardiovascular Medicine & Sciences, British Heart Foundation Centre of Research Excellence, Faculty of Life Sciences & Medicine, King's College London, 150 Stamford Street, London SE1 9NH, UK.
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849
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Abstract
Globally, diabetes is the leading cause of chronic kidney disease and end-stage renal disease, which are major risk factors for cardiovascular disease and death. Despite this burden, the factors that precipitate the development and progression of diabetic kidney disease (DKD) remain to be fully elucidated. Mitochondrial dysfunction is associated with kidney disease in nondiabetic contexts, and increasing evidence suggests that dysfunctional renal mitochondria are pathological mediators of DKD. These complex organelles have a broad range of functions, including the generation of ATP. The kidneys are mitochondrially rich, highly metabolic organs that require vast amounts of ATP for their normal function. The delivery of metabolic substrates for ATP production, such as fatty acids and oxygen, is altered by diabetes. Changes in metabolic fuel sources in diabetes to meet ATP demands result in increased oxygen consumption, which contributes to renal hypoxia. Inherited factors including mutations in genes that impact mitochondrial function and/or substrate delivery may also be important risk factors for DKD. Hence, we postulate that the diabetic milieu and inherited factors that underlie abnormalities in mitochondrial function synergistically drive the development and progression of DKD.
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Affiliation(s)
- Josephine M Forbes
- Glycation and Diabetes Group, Mater Research Institute, The University of Queensland, Translational Research Institute, Brisbane, Queensland, Australia.,Mater Clinical School, School of Medicine, The University of Queensland, St Lucia, Queensland, Australia.,Departments of Medicine and Paediatrics, The University of Melbourne, Parkville, Victoria, Australia
| | - David R Thorburn
- Departments of Medicine and Paediatrics, The University of Melbourne, Parkville, Victoria, Australia.,Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
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850
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Chung KW, Lee EK, Lee MK, Oh GT, Yu BP, Chung HY. Impairment of PPAR α and the Fatty Acid Oxidation Pathway Aggravates Renal Fibrosis during Aging. J Am Soc Nephrol 2018; 29:1223-1237. [PMID: 29440279 DOI: 10.1681/asn.2017070802] [Citation(s) in RCA: 161] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 01/03/2018] [Indexed: 01/07/2023] Open
Abstract
Defects in the renal fatty acid oxidation (FAO) pathway have been implicated in the development of renal fibrosis. Although, compared with young kidneys, aged kidneys show significantly increased fibrosis with impaired kidney function, the mechanisms underlying the effects of aging on renal fibrosis have not been investigated. In this study, we investigated peroxisome proliferator-activated receptor α (PPARα) and the FAO pathway as regulators of age-associated renal fibrosis. The expression of PPARα and the FAO pathway-associated proteins significantly decreased with the accumulation of lipids in the renal tubular epithelial region during aging in rats. In particular, decreased PPARα protein expression associated with increased expression of PPARα-targeting microRNAs. Among the microRNAs with increased expression during aging, miR-21 efficiently decreased PPARα expression and impaired FAO when ectopically expressed in renal epithelial cells. In cells pretreated with oleic acid to induce lipid stress, miR-21 treatment further enhanced lipid accumulation. Furthermore, treatment with miR-21 significantly exacerbated the TGF-β-induced fibroblast phenotype of epithelial cells. We verified the physiologic importance of our findings in a calorie restriction model. Calorie restriction rescued the impaired FAO pathway during aging and slowed fibrosis development. Finally, compared with kidneys of aged littermate controls, kidneys of aged PPARα-/- mice showed exaggerated lipid accumulation, with decreased activity of the FAO pathway and a severe fibrosis phenotype. Our results suggest that impaired renal PPARα signaling during aging aggravates renal fibrosis development, and targeting PPARα is useful for preventing age-associated CKD.
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Affiliation(s)
- Ki Wung Chung
- Molecular Inflammation Research Center for Aging Intervention and.,Department of Pharmacy, College of Pharmacy, Pusan National University, Busan, Republic of Korea
| | - Eun Kyeong Lee
- Molecular Inflammation Research Center for Aging Intervention and.,Department of Pharmacy, College of Pharmacy, Pusan National University, Busan, Republic of Korea.,Korea Institute of Toxicology, Yuseong-gu, Daejeon, Republic of Korea
| | - Mi Kyung Lee
- Department of Pathology, Ilsin Christian Hospital, Busan, Republic of Korea
| | - Goo Taeg Oh
- Department of Life Sciences, Ewha Womans University, Seoul, Republic of Korea; and
| | - Byung Pal Yu
- Department of Physiology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Hae Young Chung
- Molecular Inflammation Research Center for Aging Intervention and .,Department of Pharmacy, College of Pharmacy, Pusan National University, Busan, Republic of Korea
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