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Hua W, Peng L, Chen XM, Jiang X, Hu J, Jiang XH, Xiang X, Wan J, Long Y, Xiong J, Ma X, Du X. CD36-mediated podocyte lipotoxicity promotes foot process effacement. Open Med (Wars) 2024; 19:20240918. [PMID: 38584832 PMCID: PMC10996993 DOI: 10.1515/med-2024-0918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/07/2024] [Accepted: 02/09/2024] [Indexed: 04/09/2024] Open
Abstract
Background Lipid metabolism disorders lead to lipotoxicity. The hyperlipidemia-induced early stage of renal injury mainly manifests as podocyte damage. CD36 mediates fatty acid uptake and the subsequent accumulation of toxic lipid metabolites, resulting in podocyte lipotoxicity. Methods Male Sprague-Dawley rats were divided into two groups: the normal control group and the high-fat diet group (HFD). Podocytes were cultured and treated with palmitic acid (PA) and sulfo-N-succinimidyl oleate (SSO). Protein expression was measured by immunofluorescence and western blot analysis. Boron-dipyrromethene staining and Oil Red O staining was used to analyze fatty acid accumulation. Results Podocyte foot process (FP) effacement and marked proteinuria occurred in the HFD group. CD36 protein expression was upregulated in the HFD group and in PA-treated podocytes. PA-treated podocytes showed increased fatty acid accumulation, reactive oxygen species (ROS) production, and actin cytoskeleton rearrangement. However, pretreatment with the CD36 inhibitor SSO decreased lipid accumulation and ROS production and alleviated actin cytoskeleton rearrangement in podocytes. The antioxidant N-acetylcysteine suppressed PA-induced podocyte FP effacement and ROS generation. Conclusions CD36 participated in fatty acid-induced FP effacement in podocytes via oxidative stress, and CD36 inhibitors may be helpful for early treatment of kidney injury.
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Affiliation(s)
- Wei Hua
- Department of Nephrology, The First Affiliated Hospital of Chongqing Medical and Pharmaceutical College, Chongqing400000, China
| | - Lan Peng
- Basic Department, Chongqing Medical and Pharmaceutical College, Chongqing401331, China
| | - Xue-mei Chen
- Emergency Department, The First Affiliated Hospital of Chongqing Medical University, Chongqing400042, China
| | - XuShun Jiang
- Department of Nephrology, The First Affiliated Hospital of Chongqing Medical University, Chongqing400042, China
| | - JianGuo Hu
- Department of Obstetrics and Gynecology, Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Xian-Hong Jiang
- Department of Nephrology, The First Affiliated Hospital of Chongqing Medical and Pharmaceutical College, Chongqing400000, China
| | - Xu Xiang
- Department of Nephrology, The First Affiliated Hospital of Chongqing Medical and Pharmaceutical College, Chongqing400000, China
| | - Jiangmin Wan
- Department of Nephrology, People’s Hospital of Qijiang District, Chongqing401420, China
| | - Yingfei Long
- Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Chongqing Medical University, Chongqing, 401120, China
| | | | - Xueyi Ma
- Department of Nephrology, The First Affiliated Hospital of Chongqing Medical and Pharmaceutical College, Chongqing400000, China
| | - Xiaogang Du
- Department of Nephrology, The First Affiliated Hospital of Chongqing Medical University, Youyi Road 1, Chongqing 400042, China
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2
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Ma Y, Huang L, Zhang Z, Yang P, Chen Q, Zeng X, Tan F, Wang C, Ruan X, Liao X. CD36 promotes tubular ferroptosis by regulating the ubiquitination of FSP1 in acute kidney injury. Genes Dis 2024; 11:449-463. [PMID: 37588197 PMCID: PMC10425750 DOI: 10.1016/j.gendis.2022.12.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/20/2022] [Accepted: 12/01/2022] [Indexed: 01/05/2023] Open
Abstract
Reactive oxidative species (ROS) production-driven ferroptosis plays a role in acute kidney injury (AKI). However, its exact molecular mechanism is poorly understood. Scavenger receptor CD36 has important roles in oxidizing lipids, lipid accumulation, metabolic syndrome, and insulin resistance in chronic kidney disease, but its roles remain unexplored in AKI. The present study investigated the role and mechanism of CD36 in regulating proximal tubular cell ferroptosis and AKI. The expression of CD36 was found to be significantly up-regulated in AKI renal tissues and correlated with renal function, which might serve as an independent biomarker for AKI patients. Moreover, in adult mice subjected to AKI, deletion of CD36 (CD36-/-) induced tubular cell ROS accumulation, ferroptosis activation, and renal injury. Mechanistically, combining LC-MS/MS, co-IP, and ubiquitination analyses revealed that CD36 could specifically bind to ferroptosis suppressor protein 1 (FSP1) and regulate its ubiquitination at sites K16 and K24, leading to FSP1 degradation and progression of ferroptosis in AKI. The present results emphasize a novel mechanism of CD36 in cisplatin-induced AKI. The discovery of the special CD36 roles in promoting ferroptosis and AKI development by regulating the ubiquitination of FSP1 in proximal tubular cells may be potential therapeutic targets for AKI. Moreover, CD36 may play a key role in the progression of AKI. Therefore, targeting CD36 may provide a promising treatment option for AKI.
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Affiliation(s)
- Yixin Ma
- Department of Nephrology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
| | - Lili Huang
- Department of Nephrology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
| | - Zheng Zhang
- Department of Nephrology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
- Department of Cell Biology and Genetics, Chongqing Medical University, Chongqing 400016, China
| | - Pengfei Yang
- Department of Nephrology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
| | - Qingsong Chen
- Department of Nephrology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
| | - Xujia Zeng
- Department of Nephrology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
| | - Fangyan Tan
- Department of Nephrology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
| | - Chunxia Wang
- Department of Nephrology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
| | - Xiongzhong Ruan
- Centre for Nephrology, Royal Free and University College Medical School, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, United Kingdom
- Centre for Lipid Research, Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing 400016, China
- Kuanren Laboratory of Translational Lipidology, Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Xiaohui Liao
- Department of Nephrology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010, China
- Kuanren Laboratory of Translational Lipidology, Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
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Romualdo GR, de Souza JLH, Valente LC, Barbisan LF. Assessment of the impact of glyphosate and 2,4-D herbicides on the kidney injury and transcriptome changes in obese mice fed a Western diet. Toxicol Lett 2023; 385:1-11. [PMID: 37567420 DOI: 10.1016/j.toxlet.2023.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 07/21/2023] [Accepted: 08/07/2023] [Indexed: 08/13/2023]
Abstract
The development of chronic kidney disease has been associated with comorbidities resulting from the consumption of Westernized dietary (WD) patterns, including obesity and other metabolic dysfunctions. Kidneys also have a crucial role in the metabolism and excretion of xenobiotics, including herbicides. There is limited knowledge regarding the simultaneous exposure to WD and glyphosate (glypho) and 2,4-D, the most used herbicides globally. Thus, this study examined whether exposure to glypho and/or 2,4-D, either individually or in mixed, could impact the early effects of WD intake on kidney histology and gene expression in a rodent model. Male C57BL6J mice were fed a WD containing 20% lard, 0.2% cholesterol, 20% sucrose, and high sugar solution with 23.1 and 18.9 g/L of D-fructose and D-glucose for six months. During this period, the mice also received glypho (0.05 or 5 mg/kg/day), 2,4-D (0.02 or 2 mg/kg/day), or a mixture of both (0.05 +0.02, 5 +2 mg/kg/day) via intragastric administration five times per week. The doses were within or below the established regulatory limits. While single or mixed exposures did not alter WD-induced obesity, tubular lipid vacuolation, or increased serum creatinine levels; the exposure to higher doses of the mixture (5 +2) reduced the mesangial matrix area and tubular cell proliferation, while increasing the density of F4/80 macrophages in the renal interstitium. In terms of transcriptomic analysis, the herbicide mixture altered the expression of 415 genes in the kidney, which were found to be associated with immune response processes, particularly those related to phagocyte activity. While discrete, findings indicate that herbicide mixtures, rather than single exposures, might induce minor deleterious effects on the kidneys of obese mice under WD intake.
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Affiliation(s)
- Guilherme Ribeiro Romualdo
- São Paulo State University (UNESP), Botucatu Medical School, Experimental Research Unit (UNIPEX), Multimodel Drug Screening Platform - Laboratory of Chemically Induced and Experimental Carcinogenesis (MDSP-LCQE), Botucatu, SP, Brazil; São Paulo State University (UNESP), Biosciences Institute, Department of Structural and Functional Biology, Laboratory of Chemically Induced and Experimental Carcinogenesis (LCQE), Botucatu, SP, Brazil
| | - Jéssica Luri Hisano de Souza
- São Paulo State University (UNESP), Biosciences Institute, Department of Structural and Functional Biology, Laboratory of Chemically Induced and Experimental Carcinogenesis (LCQE), Botucatu, SP, Brazil
| | - Letícia Cardoso Valente
- São Paulo State University (UNESP), Botucatu Medical School, Experimental Research Unit (UNIPEX), Multimodel Drug Screening Platform - Laboratory of Chemically Induced and Experimental Carcinogenesis (MDSP-LCQE), Botucatu, SP, Brazil; São Paulo State University (UNESP), Biosciences Institute, Department of Structural and Functional Biology, Laboratory of Chemically Induced and Experimental Carcinogenesis (LCQE), Botucatu, SP, Brazil; São Paulo State University (UNESP), Botucatu Medical School, Botucatu, SP, Brazil
| | - Luís Fernando Barbisan
- São Paulo State University (UNESP), Biosciences Institute, Department of Structural and Functional Biology, Laboratory of Chemically Induced and Experimental Carcinogenesis (LCQE), Botucatu, SP, Brazil.
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Kanbay M, Copur S, Demiray A, Sag AA, Covic A, Ortiz A, Tuttle KR. Fatty kidney: A possible future for chronic kidney disease research. Eur J Clin Invest 2022; 52:e13748. [PMID: 35040119 DOI: 10.1111/eci.13748] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 01/15/2022] [Accepted: 01/16/2022] [Indexed: 12/01/2022]
Abstract
BACKGROUND Metabolic syndrome is a growing twenty-first century pandemic associated with multiple clinical comorbidities ranging from cardiovascular diseases, non-alcoholic fatty liver disease and polycystic ovary syndrome to kidney dysfunction. A novel area of research investigates the concept of fatty kidney in the pathogenesis of chronic kidney disease, especially in patients with diabetes mellitus or metabolic syndrome. AIM To review the most updated literature on fatty kidney and provide future research, diagnostic and therapeutic perspectives on a disease increasingly affecting the contemporary world. MATERIALS AND METHOD We performed an extensive literature search through three databases including Embase (Elsevier) and the Cochrane Central Register of Controlled Trials (Wiley) and PubMed/Medline Web of Science in November 2021 by using the following terms and their combinations: 'fatty kidney', 'ectopic fat', 'chronic kidney disease', 'cardiovascular event', 'cardio-metabolic risk', 'albuminuria' and 'metabolic syndrome'. Each study has been individually assessed by the authors. RESULTS Oxidative stress and inflammation, Klotho deficiency, endoplasmic reticulum stress, mitochondrial dysfunction and disruption of cellular energy balance appear to be the main pathophysiological mechanisms leading to tissue damage following fat accumulation. Despite the lack of large-scale comprehensive studies in this novel field of research, current clinical trials demonstrate fatty kidney as an independent risk factor for the development of chronic kidney disease and cardiovascular events. CONCLUSION The requirement for future studies investigating the pathophysiology, clinical outcomes and therapeutics of fatty kidney is clear.
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Affiliation(s)
- Mehmet Kanbay
- Division of Nephrology, Department of Medicine, Koc University School of Medicine, Istanbul, Turkey
| | - Sidar Copur
- Department of Medicine, Koc University School of Medicine, Istanbul, Turkey
| | - Atalay Demiray
- Department of Medicine, Koc University School of Medicine, Istanbul, Turkey
| | - Alan A Sag
- Division of Vascular and Interventional Radiology, Department of Radiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Adrian Covic
- Department of Nephrology, Grigore T. Popa' University of Medicine, Iasi, Romania
| | - Alberto Ortiz
- Department of Medicine, Universidad Autonoma de Madrid and IIS-Fundacion Jimenez Diaz, Madrid, Spain
| | - Kathherine R Tuttle
- Division of Nephrology, University of Washington, Seattle, Washington, USA.,Providence Medical Research Center, Providence Health Care, Spokane, Washington, USA
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5
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Byun JH, Lebeau PF, Platko K, Carlisle RE, Faiyaz M, Chen J, MacDonald ME, Makda Y, Yousof T, Lynn EG, Dickhout JG, Krepinsky JC, Weaver F, Igdoura SA, Seidah NG, Austin RC. Inhibitory Antibodies against PCSK9 Reduce Surface CD36 and Mitigate Diet-Induced Renal Lipotoxicity. KIDNEY360 2022; 3:1394-1410. [PMID: 36176646 PMCID: PMC9416829 DOI: 10.34067/kid.0007022021] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 04/26/2022] [Indexed: 01/11/2023]
Abstract
Background PCSK9 modulates the uptake of circulating lipids through a range of receptors, including the low-density lipoprotein receptor (LDLR) and CD36. In the kidney, CD36 is known to contribute to renal injury through pro-inflammatory and -fibrotic pathways. In this study, we sought to investigate the role of PCSK9 in modulating renal lipid accumulation and injury through CD36 using a high fat diet (HFD)-induced murine model. Methods The effect of PCSK9 on the expression of CD36 and intracellular accumulation of lipid was examined in cultured renal cells and in the kidneys of male C57BL/6J mice. The effect of these findings was subsequently explored in a model of HFD-induced renal injury in Pcsk9 -/- and Pcsk9 +/+ littermate control mice on a C57BL/6J background. Results In the absence of PCSK9, we observed heightened CD36 expression levels, which increased free fatty acid (FFA) uptake in cultured renal tubular cells. As a result, PCSK9 deficiency was associated with an increase in long-chain saturated FFA-induced ER stress. Consistent with these observations, Pcsk9-/- mice fed a HFD displayed elevated ER stress, inflammation, fibrosis, and renal injury relative to HFD-fed control mice. In contrast to Pcsk9-/- mice, pretreatment of WT C57BL/6J mice with evolocumab, an anti-PCSK9 monoclonal antibody (mAb) that binds to and inhibits the function of circulating PCSK9, protected against HFD-induced renal injury in association with reducing cell surface CD36 expression on renal epithelia. Conclusions We report that circulating PCSK9 modulates renal lipid uptake in a manner dependent on renal CD36. In the context of increased dietary fat consumption, the absence of circulating PCSK9 may promote renal lipid accumulation and subsequent renal injury. However, although the administration of evolocumab blocks the interaction of PCSK9 with the LDLR, this evolocumab/PCSK9 complex can still bind CD36, thereby protecting against HFD-induced renal lipotoxicity.
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Affiliation(s)
- Jae Hyun Byun
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe’s Hamilton and The Hamilton Centre for Kidney Research, Hamilton, Canada
| | - Paul F. Lebeau
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe’s Hamilton and The Hamilton Centre for Kidney Research, Hamilton, Canada
| | - Khrystyna Platko
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe’s Hamilton and The Hamilton Centre for Kidney Research, Hamilton, Canada
| | - Rachel E. Carlisle
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe’s Hamilton and The Hamilton Centre for Kidney Research, Hamilton, Canada
| | - Mahi Faiyaz
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe’s Hamilton and The Hamilton Centre for Kidney Research, Hamilton, Canada
| | - Jack Chen
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe’s Hamilton and The Hamilton Centre for Kidney Research, Hamilton, Canada
| | - Melissa E. MacDonald
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe’s Hamilton and The Hamilton Centre for Kidney Research, Hamilton, Canada
| | - Yumna Makda
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe’s Hamilton and The Hamilton Centre for Kidney Research, Hamilton, Canada
| | - Tamana Yousof
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe’s Hamilton and The Hamilton Centre for Kidney Research, Hamilton, Canada
| | - Edward G. Lynn
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe’s Hamilton and The Hamilton Centre for Kidney Research, Hamilton, Canada
| | - Jeffrey G. Dickhout
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe’s Hamilton and The Hamilton Centre for Kidney Research, Hamilton, Canada
| | - Joan C. Krepinsky
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe’s Hamilton and The Hamilton Centre for Kidney Research, Hamilton, Canada
| | - Fiona Weaver
- Department of Biology and Pathology and Molecular Medicine, McMaster University, Hamilton, Canada
| | - Suleiman A. Igdoura
- Department of Biology and Pathology and Molecular Medicine, McMaster University, Hamilton, Canada
| | - Nabil G. Seidah
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, University of Montreal, Montreal, Canada
| | - Richard C. Austin
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe’s Hamilton and The Hamilton Centre for Kidney Research, Hamilton, Canada
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6
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Sun DQ, Wang TY, Zheng KI, Zhang HY, Wang XD, Targher G, Byrne CD, Chen YP, Yuan WJ, Jin Y, Zheng MH. The HSD17B13 rs72613567 variant is associated with lower levels of albuminuria in patients with biopsy-proven nonalcoholic fatty liver disease. Nutr Metab Cardiovasc Dis 2021; 31:1822-1831. [PMID: 33853719 DOI: 10.1016/j.numecd.2021.02.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 01/13/2021] [Accepted: 02/16/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND AIMS Several susceptibility gene variants predisposing to nonalcoholic fatty liver disease (NAFLD) have been identified in chronic kidney disease (CKD). Evidence supports that 17-beta hydroxysteroid dehydrogenase 13 (HSD17B13) rs72613567 plays a role in NAFLD development by affecting lipid homeostasis. Since lipid droplets may accumulate in the kidneys and contribute to renal injury, we investigated the association between the HSD17B13 rs72613567 variant and markers of renal function/injury in NAFLD. METHODS AND RESULTS We measured estimated glomerular filtration rate (eGFR), urinary/serum neutrophil gelatinase-associated lipocalin (NGAL), and urinary albumin-to-creatinine ratio (u-ACR) in individuals with biopsy-proven NAFLD. Multivariable regression analyses were undertaken to examine the associations between the HSD17B13 rs72613567 variant and markers of renal function/injury. Individuals were stratified by HSD17B13 rs72613567 genotypes into -/-, A/- and A/A groups. HSD17B13 rs72613567 genotypes were not significantly associated with eGFR and urinary/serum NGAL levels. Conversely, the prevalence of abnormal albuminuria in the A/- + A/A group was lower than in the -/- group (4.92% vs. 19.35%, p = 0.001). Additionally, the mean u-ACR levels were lower among carriers of the A/- or A/A genotypes with coexisting hypertension or diabetes, than among those with the -/- genotype. The risk of abnormal albuminuria (adjusted-odds ratio 0.16, p = 0.001) remained significantly lower in the A/- + A/A group after adjustment for established renal risk factors and histologic severity of NAFLD. CONCLUSION HSD17B13 rs72613567: A allele is associated with a lower risk of having abnormal albuminuria, but not with lower eGFR or urinary/serum NGAL levels, in patients with biopsy-proven NAFLD.
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Affiliation(s)
- Dan-Qin Sun
- Affiliated Wuxi Clinical College of Nantong University, Wuxi, China; Department of Nephrology, The Affiliated Wuxi No.2 People's Hospital of Nanjing Medical University, Wuxi, China; Department of Nephrology, Shanghai General Hospital of Nanjing Medical University, Shanghai, China
| | - Ting-Yao Wang
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Kenneth I Zheng
- NAFLD Research Center, Department of Hepatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Hao-Yang Zhang
- School of Biomedical Engineering, Sun Yat-sen University, Guangzhou, China
| | - Xiao-Dong Wang
- NAFLD Research Center, Department of Hepatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China; Institute of Hepatology, Wenzhou Medical University, Wenzhou, China
| | - Giovanni Targher
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University and Azienda Ospedaliera Universitaria Integrata of Verona, Verona, Italy
| | - Christopher D Byrne
- Southampton National Institute for Health Research Biomedical Research Centre, University Hospital Southampton, Southampton General Hospital, Southampton, UK
| | - Yong-Ping Chen
- NAFLD Research Center, Department of Hepatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China; Institute of Hepatology, Wenzhou Medical University, Wenzhou, China
| | - Wei-Jie Yuan
- Department of Nephrology, Shanghai General Hospital of Nanjing Medical University, Shanghai, China
| | - Yan Jin
- Affiliated Wuxi Clinical College of Nantong University, Wuxi, China; Department of Gastroenterology, the Affiliated Wuxi No.2 People's Hospital of Nanjing Medical University, Wuxi, China.
| | - Ming-Hua Zheng
- NAFLD Research Center, Department of Hepatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China; Institute of Hepatology, Wenzhou Medical University, Wenzhou, China; Key Laboratory of Diagnosis and Treatment for The Development of Chronic Liver Disease in Zhejiang Province, Wenzhou, China.
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7
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Lin PH, Duann P. Dyslipidemia in Kidney Disorders: Perspectives on Mitochondria Homeostasis and Therapeutic Opportunities. Front Physiol 2020; 11:1050. [PMID: 33013450 PMCID: PMC7494972 DOI: 10.3389/fphys.2020.01050] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 07/30/2020] [Indexed: 12/11/2022] Open
Abstract
To excrete body nitrogen waste and regulate electrolyte and fluid balance, the kidney has developed into an energy factory with only second to the heart in mitochondrial content in the body to meet the high-energy demand and regulate homeostasis. Energy supply from the renal mitochondria majorly depends on lipid metabolism, with programed enzyme systems in fatty acid β-oxidation and Krebs cycle. Renal mitochondria integrate several metabolic pathways, including AMPK/PGC-1α, PPARs, and CD36 signaling to maintain energy homeostasis for dynamic and static requirements. The pathobiology of several kidney disorders, including diabetic nephropathy, acute and chronic kidney injuries, has been primarily linked to impaired mitochondrial bioenergetics. Such homeostatic disruption in turn stimulates a pathological adaptation, with mitochondrial enzyme system reprograming possibly leading to dyslipidemia. However, this alteration, while rescuing oncotic pressure deficit secondary to albuminuria and dissipating edematous disorder, also imposes an ominous lipotoxic consequence. Reprograming of lipid metabolism in kidney injury is essential to preserve the integrity of kidney mitochondria, thereby preventing massive collateral damage including excessive autophagy and chronic inflammation. Here, we review dyslipidemia in kidney disorders and the most recent advances on targeting mitochondrial energy metabolism as a therapeutic strategy to restrict renal lipotoxicity, achieve salutary anti-edematous effects, and restore mitochondrial homeostasis.
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Affiliation(s)
- Pei-Hui Lin
- Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States
| | - Pu Duann
- Research and Development, Salem Veteran Affairs Medical Center, Salem, VA, United States
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8
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Zhu ZB, Song K, Huang WJ, Li H, Yang H, Bai YQ, Guo KT, Yang RB, Lou WJ, Xia CH, Nie B, Liu WJ. Si-Miao-Yong-An (SMYA) Decoction May Protect the Renal Function Through Regulating the Autophagy-Mediated Degradation of Ubiquitinated Protein in an Atherosclerosis Model. Front Pharmacol 2020; 11:837. [PMID: 32714182 PMCID: PMC7343850 DOI: 10.3389/fphar.2020.00837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 05/21/2020] [Indexed: 12/03/2022] Open
Abstract
Hyperlipidemia is common, and its renal toxicity has attracted a great deal of attention. Si-miao-yong-an (SMYA) is a famous ancient decoction of traditional Chinese medicine (TCM), which is still widely used in clinical treatment. In this study, we observed and explored its efficacy and mechanism in protecting renal function in an atherosclerosis model. The results showed that the serum, Cr urinal KIM-1, and NGAL were significantly decreased in SMYA group. Although SMYA failed to alleviate the lipid accumulation, decrease p-NFκB, or increase SOD in kidney tissue, the levels of ubiquitinated protein and P62 were decreased in SMYA group. What is more, a higher LC3 II level was observed in the SMYA group. In conclusion, these data indicated that SMYA decoction may protect renal function in hyperlipidemia via regulating the autophagy-mediated degradation of ubiquitinated protein.
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Affiliation(s)
- Ze-Bing Zhu
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China.,Renal Research Institute of Beijing University of Chinese Medicine, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Ke Song
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Wei-Jun Huang
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China.,Renal Research Institute of Beijing University of Chinese Medicine, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Hui Li
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Hui Yang
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Yun-Qi Bai
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Ke-Ting Guo
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China.,Renal Research Institute of Beijing University of Chinese Medicine, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Rui-Bing Yang
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China.,Renal Research Institute of Beijing University of Chinese Medicine, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Wen-Jiao Lou
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China.,Renal Research Institute of Beijing University of Chinese Medicine, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Chen-Hui Xia
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China.,Renal Research Institute of Beijing University of Chinese Medicine, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Bo Nie
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Wei-Jing Liu
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China.,Renal Research Institute of Beijing University of Chinese Medicine, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
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9
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Yang S, Cao C, Deng T, Zhou Z. Obesity-Related Glomerulopathy: A Latent Change in Obesity Requiring More Attention. Kidney Blood Press Res 2020; 45:510-522. [PMID: 32498064 DOI: 10.1159/000507784] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Accepted: 04/06/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Obesity has become a major public health problem, and the prevalence of kidney diseases has increased in parallel. Among kidney diseases caused by metabolic disorders, obesity-related glomerulopathy (ORG) is secondary to obesity. SUMMARY ORG is mainly caused by glomerular hyperfiltration, dysregulation of hormone and cytokine secretion in adipose tissues, and ectopic lipid accumulation in renal cells. ORG is pathologically characterized by glomerular hypertrophy, with or without focal and segmental glomerulosclerosis. Patients with ORG usually present with proteinuria concomitant with metabolic disorders such as dyslipidemia and hypertension. Weight loss, RAAS inhibitors, and improved insulin resistance can reduce the progression of ORG. CONCLUSION ORG is a growing renal pathological change in obese individuals, and a comprehensive understanding of the disease is pivotal to avoid its occurrence and improve quality of life for those with obesity. Key Messages:This review comprehensively describes the characteristics of ORG in pathological changes, clinical manifestations, pathogeneses and treatments.
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Affiliation(s)
- Shuting Yang
- Department of Metabolism and Endocrinology, The Second Xiangya Hospital, Central South University, Changsha, China.,Key Laboratory of Diabetes Immunology (Central South University), Ministry of Education, Changsha, China.,National Clinical Research Center for Metabolic Diseases, Changsha, China
| | - Chuqing Cao
- Department of Metabolism and Endocrinology, The Second Xiangya Hospital, Central South University, Changsha, China.,Key Laboratory of Diabetes Immunology (Central South University), Ministry of Education, Changsha, China.,National Clinical Research Center for Metabolic Diseases, Changsha, China
| | - Tuo Deng
- Department of Metabolism and Endocrinology, The Second Xiangya Hospital, Central South University, Changsha, China.,Key Laboratory of Diabetes Immunology (Central South University), Ministry of Education, Changsha, China.,National Clinical Research Center for Metabolic Diseases, Changsha, China
| | - Zhiguang Zhou
- Department of Metabolism and Endocrinology, The Second Xiangya Hospital, Central South University, Changsha, China, .,Key Laboratory of Diabetes Immunology (Central South University), Ministry of Education, Changsha, China, .,National Clinical Research Center for Metabolic Diseases, Changsha, China,
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10
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Liu H, Deng Y, Wu L, Li Y, Lin N, Li W, Dong X, Ma L. Interleukin-1β Regulates Lipid Homeostasis in Human Glomerular Mesangial Cells. J Nutr Health Aging 2020; 24:246-250. [PMID: 32115603 DOI: 10.1007/s12603-019-1302-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Recent studies have shown that hyperlipidemia is closely related to the progression of kidney disease and glomerulosclerosis has similar pathophysiological mechanisms with atherosclerosis. Atherosclerosis is essentially a chronic inflammatory process and various kidney diseases are characterized by a micro-inflammatory state. Hyperlipidemia levels are not parallel to the degree of glomerulosclerosis, inflammatory factors together with lipids may contribute to the pathogenesis of glomerulosclerosis. Therefore, it is key to clarify lipid-mediated renal injury through studying the mechanism by which inflammation affects cholesterol homeostasis at the cellular level. Intracellular lipid homeostasis involves both lipid uptake and excretion, therefore in this study, we aimed to explore whether interleukin-1β (IL-1β) promotes the uptake of oxidized low-density lipoprotein (Ox-LDL) to increase in intracellular lipid levels, and to clarify the effect of IL-1β on the expression of lectin-like oxidized LDL receptor 1 (LOX-1) and ATP-binding cassette transporter A1 (ABCA1), which may regulate cholesterol homeostasis in human mesangial cells (HMCs). METHODS The effect of IL-1β on uptake of Ox-LDL labeled with fluorescent Dil (Dil-Ox-LDL) by HMCs was observed using laser confocal microscopy. The effect of IL-1β on LOX-1 and ABCA1 expression in HMCs was detected by polymerase chain reaction and western blotting. RESULTS Laser confocal microscopy revealed that HMCs took up Dil-Ox-LDL. Treatment of HMCs with 5 ng/ml IL-1β for 24 h significantly increased uptake of Dil-Ox-LDL. IL-1β also promoted LOX-1 mRNA and protein expression in a dose-dependent manner. Moreover, ABCA1 mRNA and protein expression were reduced by IL-1β in lipid-loaded HMCs in a dose-dependent manner. CONCLUSIONS IL-1β promotes the uptake of Ox-LDL and expression of LOX-1 in HMCs, whereas it inhibits expression of ABCA1 under lipid load. The imbalance in intracellular cholesterol resulted by IL-1β can in turn transform HMCs into foam cells and aggravate glomerulosclerosis.
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Affiliation(s)
- H Liu
- Dr. Hua Liu, Department of Nephrology, Xuan Wu Hospital, Capital Medical University, Beijing 100053, China, e-mail: , Tel: +(86)18911651038; Dr. Lina Ma, Department of Geriatrics, Xuan Wu Hospital, Capital Medical University, Beijing 100053, China, e-mail: , Tel: +(86)17600107787
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11
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Liu H, Li Y, Lin N, Dong X, Li W, Deng Y, Ma L. Interleukin-1β Promotes Ox-LDL Uptake by Human Glomerular Mesangial Cells via LOX-1. Int J Med Sci 2020; 17:1056-1061. [PMID: 32410835 PMCID: PMC7211151 DOI: 10.7150/ijms.43981] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 03/30/2020] [Indexed: 01/26/2023] Open
Abstract
The aim of this study was to determine whether interleukin-1β (IL-1β) promotes oxidised low-density lipoprotein (Ox-LDL) uptake by human glomerular mesangial cells (HMCs) and its effect on the expression of lectin-like Ox-LDL receptor 1 (LOX-1) and to identify pathways through which IL-1β affects lipid uptake. Confocal laser scanning microscopy and flow cytometry were used to observe the effect of IL-1β on lipid uptake by HMCs and the pathway by which IL-1β may mediate lipid uptake. Real-time polymerase chain reaction (PCR) and western blotting were used to evaluate the effect of IL-1β on LOX-1 expression. Confocal laser scanning microscopy and flow cytometry revealed that IL-1β promoted uptake of fluorescent Dil-labelled Ox-LDL(Dil-Ox-LDL) by HMCs and the enhanced uptake of Dil-Ox-LDL was partially inhibited by an anti-LOX-1 antibody evaluated by flow cytometry. Further, IL-1β promoted LOX-1 mRNA and protein expression of HMCs in a dose- and time-dependent manner. Thus, Ox-LDL is ingested by HMCs under basic conditions. Inflammatory cytokine IL-1β promotes Ox-LDL uptake by HMCs. Furthermore, IL-1β promotes the mRNA and protein expression of LOX-1, a specific receptor of Ox-LDL, suggesting that the enhancement of Ox-LDL uptake may be mediated by LOX-1 pathway. Anti-LOX-1 therapy may be a promising option for treatment of glomerulosclerosis.
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Affiliation(s)
- Hua Liu
- Department of Nephrology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Yinping Li
- Department of Nephrology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Na Lin
- Department of Nephrology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Xingtong Dong
- Department of Nephrology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Wen Li
- Department of Nephrology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Yinghui Deng
- Department of Nephrology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Lina Ma
- Department of Geriatrics, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
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12
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Yang H, Li H. CD36 identified by weighted gene co-expression network analysis as a hub candidate gene in lupus nephritis. PeerJ 2019; 7:e7722. [PMID: 31592160 PMCID: PMC6777479 DOI: 10.7717/peerj.7722] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 08/22/2019] [Indexed: 12/18/2022] Open
Abstract
Lupus nephritis (LN) is a severe manifestation of systemic lupus erythematosus (SLE), which often progresses to end-stage renal disease (ESRD) and ultimately leads to death. At present, there are no definitive therapies towards LN, so that illuminating the molecular mechanism behind the disease has become an urgent task for researchers. Bioinformatics has become a widely utilized method for exploring genes related to disease. This study set out to conduct weighted gene co-expression network analysis (WGCNA) and screen the hub gene of LN. We performed WGCNA on the microarray expression profile dataset of GSE104948 from the Gene Expression Omnibus (GEO) database with 18 normal and 21 LN samples of glomerulus. A total of 5,942 genes were divided into 5 co-expression modules, one of which was significantly correlated to LN. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted on the LN-related module, and the module was proved to be associated mainly with the activation of inflammation, immune response, cytokines, and immune cells. Genes in the most significant GO terms were extracted for sub-networks of WGNCA. We evaluated the centrality of genes in the sub-networks by Maximal Clique Centrality (MCC) method and CD36 was ultimately screened out as a hub candidate gene of the pathogenesis of LN. The result was verified by its differentially expressed level between normal and LN in GSE104948 and the other three multi-microarray datasets of GEO. Moreover, we further demonstrated that the expression level of CD36 is related to the WHO Lupus Nephritis Class of LN patients with the help of Nephroseq database. The current study proposed CD36 as a vital candidate gene in LN for the first time and CD36 may perform as a brand-new biomarker or therapeutic target of LN in the future.
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Affiliation(s)
- Huiying Yang
- Department of Nephrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| | - Hua Li
- Department of Nephrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
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13
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Lipid Accumulation and Chronic Kidney Disease. Nutrients 2019; 11:nu11040722. [PMID: 30925738 PMCID: PMC6520701 DOI: 10.3390/nu11040722] [Citation(s) in RCA: 205] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 03/25/2019] [Accepted: 03/26/2019] [Indexed: 12/12/2022] Open
Abstract
Obesity and hyperlipidemia are the most prevalent independent risk factors of chronic kidney disease (CKD), suggesting that lipid accumulation in the renal parenchyma is detrimental to renal function. Non-esterified fatty acids (also known as free fatty acids, FFA) are especially harmful to the kidneys. A concerted, increased FFA uptake due to high fat diets, overexpression of fatty acid uptake systems such as the CD36 scavenger receptor and the fatty acid transport proteins, and a reduced β-oxidation rate underlie the intracellular lipid accumulation in non-adipose tissues. FFAs in excess can damage podocytes, proximal tubular epithelial cells and the tubulointerstitial tissue through various mechanisms, in particular by boosting the production of reactive oxygen species (ROS) and lipid peroxidation, promoting mitochondrial damage and tissue inflammation, which result in glomerular and tubular lesions. Not all lipids are bad for the kidneys: polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) seem to help lag the progression of chronic kidney disease (CKD). Lifestyle interventions, especially dietary adjustments, and lipid-lowering drugs can contribute to improve the clinical outcome of patients with CKD.
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14
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Lipid Metabolism Disorder and Renal Fibrosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1165:525-541. [PMID: 31399983 DOI: 10.1007/978-981-13-8871-2_26] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Since the lipid nephrotoxicity hypothesis was proposed in 1982, increasing evidence has supported the hypothesis that lipid abnormalities contributed to the progression of glomerulosclerosis. In this chapter, we will discuss the general promises of the original hypothesis, focusing especially on the role of lipids and metabolic inflammation accompanying CKD in renal fibrosis and potential new strategies of prevention.
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15
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Li D, Chen A, Lan T, Zou Y, Zhao L, Yang P, Qu H, Wei L, Varghese Z, Moorhead JF, Chen Y, Ruan XZ. SCAP knockdown in vascular smooth muscle cells alleviates atherosclerosis plaque formation via up-regulating autophagy in ApoE -/- mice. FASEB J 2018; 33:3437-3450. [PMID: 30462530 DOI: 10.1096/fj.201800975rrr] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Sterol regulatory element binding protein (SREBP) cleavage-activating protein (SCAP) is a cholesterol sensor that plays a critical role in regulating intracellular cholesterol levels, but the association between SCAP and foam cell formation in vascular smooth muscle cells (VSMCs) is poorly understood. Using tissue-specific SCAP knockdown in apolipoprotein E (ApoE)-/- mice, we sought to search the mechanism through which SCAP signaling affects VSMC foam cell development. VSMC-specific SCAP knockdown mice were generated by Cre/LoxP-mediated gene targeting in ApoE-/- mice. Breeding SCAPflox/flox mice with SM22α-Cre mice resulted in no viable offspring with the homozygote SM22-Cre: SCAPflox/flox genotype due to embryonic lethality. We found that the heterozygote SM22α-Cre:SCAPflox/+:ApoE-/- mice fed a Western diet for 12 wk had significantly fewer atherosclerotic plaques in their aortas than the control mice due to reduced cholesterol uptake and synthesis. Furthermore, we found that autophagy in VSMCs was increased in SM22α-Cre:SCAPflox/+:ApoE-/- mice. Similarly, in vitro, SCAP knockdown in human coronary artery VSMCs by RNA interference reduced lipid accumulation and increased autophagy under LDL cholesterol loading. SCAP knockdown in VSMCs reduced oxidative stress and increased AMPK phosphorylation, which contributed to the up-regulation of autophagy in vivo and in vitro. VSMC-specific SCAP knockdown decreased the lipid accumulation and intracellular oxidative stress, increased excessive lipid clearance by enhancing lipid autophagy mediated by the reactive oxygen species/AMPK pathway in VSMCs, and consequently alleviated atherosclerosis plaque formation.-Li, D., Chen, A., Lan, T., Zou, Y., Zhao, L., Yang, P., Qu, H., Wei, L., Varghese, Z., Moorhead, J. F., Chen, Y., Ruan, X. Z. SCAP knockdown in vascular smooth muscle cells alleviates atherosclerosis plaque formation via up-regulating autophagy in ApoE-/- mice.
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Affiliation(s)
- Danyang Li
- Institute for Viral Hepatitis, Department of Infectious Diseases, Centre for Lipid Research and Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Amei Chen
- Institute for Viral Hepatitis, Department of Infectious Diseases, Centre for Lipid Research and Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Tan Lan
- Institute for Viral Hepatitis, Department of Infectious Diseases, Centre for Lipid Research and Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Yang Zou
- Institute for Viral Hepatitis, Department of Infectious Diseases, Centre for Lipid Research and Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Lei Zhao
- Institute for Viral Hepatitis, Department of Infectious Diseases, Centre for Lipid Research and Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Ping Yang
- Institute for Viral Hepatitis, Department of Infectious Diseases, Centre for Lipid Research and Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Haiyang Qu
- Institute for Viral Hepatitis, Department of Infectious Diseases, Centre for Lipid Research and Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Li Wei
- Institute for Viral Hepatitis, Department of Infectious Diseases, Centre for Lipid Research and Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Zac Varghese
- John Moorhead Research Laboratory, Centre for Nephrology, University College London Medical School, Royal Free Campus, University College London, London, United Kingdom; and
| | - John F Moorhead
- John Moorhead Research Laboratory, Centre for Nephrology, University College London Medical School, Royal Free Campus, University College London, London, United Kingdom; and
| | - Yaxi Chen
- Institute for Viral Hepatitis, Department of Infectious Diseases, Centre for Lipid Research and Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Xiong Z Ruan
- Institute for Viral Hepatitis, Department of Infectious Diseases, Centre for Lipid Research and Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China.,John Moorhead Research Laboratory, Centre for Nephrology, University College London Medical School, Royal Free Campus, University College London, London, United Kingdom; and.,The Collaborative Innovation Center (Consortium) for Diagnosis and Treatment of Infectious Diseases (CCID), Zhejiang University, Hangzhou, China
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Xie Z, Zhong L, Wu Y, Wan X, Yang H, Xu X, Li P. Carnosic acid improves diabetic nephropathy by activating Nrf2/ARE and inhibition of NF-κB pathway. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2018; 47:161-173. [PMID: 30166101 DOI: 10.1016/j.phymed.2018.04.031] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 01/22/2018] [Accepted: 04/15/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Diabetic nephropathy (DN), one of the most serious complications of diabetes, is the leading cause of morbidity and mortality of end-stage renal disease. Our previous research found that carnosic acid (CA) or rosemary extract can effectively improve glucose and lipid metabolism disorder by inhibiting SREBPs. PURPOSE In this study, we aimed to explore the therapeutic effects of CA on the DN. METHODS The mice glomerular mesangial cells (mGMCs) were used to evaluate the anti-oxidative and anti-inflammation effects of CA under high glucose (HG) condition. Furthermore, db/db mice and streptozotocin (STZ)-induced diabetic mice were used to investigate the effects of CA against DN in vivo. RESULTS The results showed that CA activated Nrf2, inhibited NF-κB pathway and regulated related downstream genes in mGMC under HG condition. A 14-week treatment of mice with CA reduced water uptake and urine volume, attenuated diabetes-induced albuminuria, increased urine creatinine, and subsequently improved the glomerular sclerosis and mesangial expansion in db/db mice. Similarly, a 20-week oral administration of CA improved kidney damage in STZ-induced diabetic mice. In addition, CA inhibited the expression of profibrotic factors, such as TGF-β1, fibronectin and E-cadherin. Compared to irbesartan, CA exerted better glucose lowering effect, and in kidney, CA was more potent to reduce fibronectin and E-cadherin expression. In all the animal experiment, CA did not lead to abnormal damages to other tissues. CONCLUSION These findings suggest that CA is a safe compound which exerts the protective effects on diabetes-induced kidney complications.
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Affiliation(s)
- Zhisheng Xie
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Lingjun Zhong
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Yanrao Wu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Xiaomeng Wan
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Hua Yang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Xiaojun Xu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
| | - Ping Li
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
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CD36 in chronic kidney disease: novel insights and therapeutic opportunities. Nat Rev Nephrol 2017; 13:769-781. [DOI: 10.1038/nrneph.2017.126] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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18
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Iriyama N, Yuan B, Hatta Y, Takagi N, Takei M. Lyn, a tyrosine kinase closely linked to the differentiation status of primary acute myeloid leukemia blasts, associates with negative regulation of all-trans retinoic acid (ATRA) and dihydroxyvitamin D3 (VD3)-induced HL-60 cells differentiation. Cancer Cell Int 2016; 16:37. [PMID: 27182202 PMCID: PMC4866426 DOI: 10.1186/s12935-016-0314-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Accepted: 05/05/2016] [Indexed: 11/21/2022] Open
Abstract
Background Lyn, an import member of Src family kinases (SFKs), is supposed to be implicated in acute myeloid leukemia (AML) pathogenesis and development by participation in AML differentiation, yet the details still remain incompletely understood. The expression status of Lyn and its correlation with multiple clinical parameters including cell differentiation degree, different cytogenetic risk classification, and the activity of myeloperoxidase (MPO) were thus investigated. To address the mechanisms underlying the involvement of Lyn in differentiation induction, the effects of dasatinib, an inhibitor for SFKs including Lyn, on the alterations of all-trans retinoic acid (ATRA)- or dihydroxyvitamin D3 (VD3)-induced differentiation, and c-Myc protein expression were investigated. Methods Primary AML blasts were obtained from 31 newly diagnosed AML patients with different French-American-British (FAB) subtypes. The expression of phosphorylated and total Lyn, c-Myc, and CD11b, CD11c and CD15 was analyzed by flow cytometry. The activation of Akt and Erk known to be involved in the regulation of c-Myc expression was investigated using western blotting. Results Significant higher expression levels of total Lyn were observed in AML patients with favorable cytogenetics, higher MPO activity and FAB M2 subtype. A clear positive correlation between the expression levels of Lyn and differentiation status of primary AML blasts was observed. Dasatinib inhibited the expression of phosphorylated Lyn, and further enhanced the differentiation-inducing activity of ATRA and VD3 in HL-60 cells. Augmented downregulation of c-Myc protein expression was observed in the combination treatment with ATRA, VD3 and dasatinib compared to treatment with each reagent alone in HL-60 cells. The suppression of the activation of Akt and Erk was also observed concomitantly. Conclusions The expression level of total Lyn is closely linked to the differentiation status of AML blasts. The enhancement of differentiation-inducing activity of ATRA/VD3 by dasatinib suggested that Lyn was associated in the negative regulation of ATRA/VD3-induced HL-60 cells differentiation. The enhancement probably was attributed to the downregulation of c-Myc implicated with the suppression of the activation of Akt and Erk. These results provide novel insights into a possible combinational therapeutic approach by targeting Lyn for AML patients, and offer new possibilities for the combination therapy with VD3 and dasatinib.
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Affiliation(s)
- Noriyoshi Iriyama
- Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Itabashi Hospital, 30-1 Oyaguchi Kamicho, Itabashi-ku, Tokyo, Japan
| | - Bo Yuan
- Department of Applied Biochemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 Japan
| | - Yoshihiro Hatta
- Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Itabashi Hospital, 30-1 Oyaguchi Kamicho, Itabashi-ku, Tokyo, Japan
| | - Norio Takagi
- Department of Applied Biochemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 Japan
| | - Masami Takei
- Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Itabashi Hospital, 30-1 Oyaguchi Kamicho, Itabashi-ku, Tokyo, Japan
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Zhong S, Zhao L, Li Q, Yang P, Varghese Z, Moorhead JF, Chen Y, Ruan XZ. Inflammatory Stress Exacerbated Mesangial Foam Cell Formation and Renal Injury via Disrupting Cellular Cholesterol Homeostasis. Inflammation 2016; 38:959-71. [PMID: 25387652 DOI: 10.1007/s10753-014-0058-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Inflammation and lipids play significant roles in the progression of chronic kidney disease. This study was designed to investigate whether inflammation disrupts cellular cholesterol homeostasis and causes the lipid nephrotoxicity in vitro and in vivo, and explored its underlying mechanisms. Inflammatory stress was induced by cytokines (interleukin-1β (IL-1β); tumor necrosis factor α (TNF-α)) to human mesangial cells (HMCs) in vitro and by subcutaneous casein injection in C57BL/6J mice in vivo. The data showed that inflammatory stress exacerbated renal cholesterol ester accumulation in vitro and in vivo. Inflammation increased cellular cholesterol uptake and synthesis via upregulating the expression of low-density lipoprotein receptor (LDLr) and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCoA-R), while it decreased cholesterol efflux via downregulating the expression of liver X receptor alpha and ATP-binding cassette transporter A1. The increased lipid accumulation by inflammatory stress induced reactive oxygen species (ROS) and increased levels of endoplasmic reticulum (ER) stress markers (inositol-requiring protein 1 and activating transcription factor 6) in HMCs and kidneys of C57BL/6J mice. This study implied that inflammation promoted renal lipid accumulation and foam cell formation by disrupting cellular cholesterol homeostasis. Increased intracellular lipids under inflammatory stress caused oxidative stress and ER stress in vitro and in vivo which may contribute to renal injury and progression of chronic kidney disease.
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Affiliation(s)
- Shan Zhong
- Centre for Lipid Research, Key Laboratory of Metabolism on Lipid and Glucose, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, 400016, China
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Obesity-Related Chronic Kidney Disease-The Role of Lipid Metabolism. Metabolites 2015; 5:720-32. [PMID: 26690487 PMCID: PMC4693192 DOI: 10.3390/metabo5040720] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 12/01/2015] [Accepted: 12/08/2015] [Indexed: 02/06/2023] Open
Abstract
Obesity is an independent risk factor for chronic kidney disease (CKD). The mechanisms linking obesity and CKD include systemic changes such as high blood pressure and hyperglycemia, and intrarenal effects relating to lipid accumulation. Normal lipid metabolism is integral to renal physiology and disturbances of renal lipid and energy metabolism are increasingly being linked with kidney disease. AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) are important regulators of fatty acid oxidation, which is frequently abnormal in the kidney with CKD. A high fat diet reduces renal AMPK activity, thereby contributing to reduced fatty acid oxidation and energy imbalance, and treatments to activate AMPK are beneficial in animal models of obesity-related CKD. Studies have found that the specific cell types affected by excessive lipid accumulation are proximal tubular cells, podocytes, and mesangial cells. Targeting disturbances of renal energy metabolism is a promising approach to addressing the current epidemic of obesity-related kidney disease.
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Chen Y, Zhao L, Li Q, Wheeler DC, Varghese Z, Moorhead JF, Powis SH, Ruan XZ. Inflammatory stress reduces the effectiveness of statins in the kidney by disrupting HMGCoA reductase feedback regulation. Nephrol Dial Transplant 2014; 29:1864-78. [PMID: 24895437 DOI: 10.1093/ndt/gfu203] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Patients with chronic kidney disease (CKD) are unlikely to gain the same benefit from conventional doses of statins as do patients with cardiovascular disease alone. This study investigated whether inflammation accompanying CKD causes statin resistance. METHODS Inflammatory stress was induced by adding cytokines and lipopolysaccharide (LPS) to human mesangial cells (HMCs) in vitro, and in vivo by subcutaneous casein injection in apolipoprotein E, scavenger receptors class A and CD36 triple knockout mice. RESULTS Inflammatory stress exacerbated cholesterol accumulation and was accompanied in vitro and in vivo by increased HMGCoA reductase (HMGCoA-R) mRNA and protein expression mediated via activation of the sterol regulatory element-binding protein cleavage-activating protein (SCAP)/sterol regulatory element-binding protein 2 pathway. Atorvastatin reduced HMGCoA-R enzymatic activity and intracellular cholesterol synthesis in vitro; however, inflammatory stress weakened these suppressive effects. Atorvastatin at concentrations of 15 µM inhibited HMGCoA-R activity by 50% (IC50) in HMCs, but the same concentration in the presence of interleukin (IL)-1β resulted in only 30% inhibition of HMGCoA-R activity in HMCs. Knocking down SCAP prevented statin resistance induced by IL-1β, and overexpression of SCAP-induced statin resistance even without inflammatory stress. In vivo, the amount of atorvastatin required to lower serum cholesterol and decrease kidney lipid accumulation rose from 2 to 10 mg/kg/day in the presence of inflammatory stress. CONCLUSIONS Inflammatory stress can disrupt HMGCoA-R-mediated cholesterol synthesis resulting in intracellular lipid accumulation and statin resistance.
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Affiliation(s)
- Yaxi Chen
- Centre for Lipid Research, Key Laboratory of Metabolism on Lipid and Glucose, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Lei Zhao
- Centre for Lipid Research, Key Laboratory of Metabolism on Lipid and Glucose, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Qing Li
- Centre for Lipid Research, Key Laboratory of Metabolism on Lipid and Glucose, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - David C Wheeler
- John Moorhead Research Laboratory, Centre for Nephrology, University College London (UCL) Medical School, Royal Free Campus, University College London, London, UK
| | - Zac Varghese
- John Moorhead Research Laboratory, Centre for Nephrology, University College London (UCL) Medical School, Royal Free Campus, University College London, London, UK
| | - John F Moorhead
- John Moorhead Research Laboratory, Centre for Nephrology, University College London (UCL) Medical School, Royal Free Campus, University College London, London, UK
| | - Stephen H Powis
- John Moorhead Research Laboratory, Centre for Nephrology, University College London (UCL) Medical School, Royal Free Campus, University College London, London, UK
| | - Xiong Z Ruan
- Centre for Lipid Research, Key Laboratory of Metabolism on Lipid and Glucose, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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22
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de Vries APJ, Ruggenenti P, Ruan XZ, Praga M, Cruzado JM, Bajema IM, D'Agati VD, Lamb HJ, Pongrac Barlovic D, Hojs R, Abbate M, Rodriquez R, Mogensen CE, Porrini E. Fatty kidney: emerging role of ectopic lipid in obesity-related renal disease. Lancet Diabetes Endocrinol 2014; 2:417-26. [PMID: 24795255 DOI: 10.1016/s2213-8587(14)70065-8] [Citation(s) in RCA: 320] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The global increase in chronic kidney disease (CKD) parallels the obesity epidemic. Obesity conveys a gradual but independent risk of progression of CKD that seems irrespective of the underlying nephropathy. Obesity has been associated with a secondary focal segmental glomerulosclerosis coined obesity-related glomerulopathy (ORG). Pathways through which obesity might cause renal disease are not well understood, and early clinical biomarkers for incipient ORG or renal relevant obesity are currently lacking. Recent human and experimental studies have associated ectopic lipid accumulation in the kidney (fatty kidney) with obesity-related renal disease. There is enough growing insight that ectopic lipid--the accumulation of lipid in non-adipose tissue--is associated with structural and functional changes of mesangial cells, podocytes, and proximal tubular cells to propose the development of ORG as a maladaptive response to hyperfiltration and albuminuria. Recent advances in metabolic imaging might validate ectopic lipid as a biomarker and research aid, to help translate novel therapeutics from experimental models to patients.
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Affiliation(s)
- Aiko P J de Vries
- Department of Nephrology, Leiden University Medical Center and Leiden University, Leiden, Netherlands.
| | - Piero Ruggenenti
- IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Clinical Research Center for Rare Diseases "Aldo e Cele Daccò", Ranica, Bergamo, Italy; Unit of Nephrology and Dialysis, Azienda Ospedaliera Papa Giovanni XXIII, Bergamo, Italy
| | - Xiong Z Ruan
- Moorhead Renal Research Laboratory, University College London, Royal Free Campus, London, UK; Centre for Nephrology and Urology, Shenzhen University Health Science Centre, Shenzhen, China
| | - Manuel Praga
- Departments of Nephrology and Medicine, Hospital 12 de Octubre, Complutense University, Madrid, Spain
| | - Josep M Cruzado
- Department of Nephrology, Hospital Universitario de Bellvitge, Barcelona, Spain
| | - Ingeborg M Bajema
- Department of Pathology, Leiden University Medical Center and Leiden University, Leiden, Netherlands
| | - Vivette D D'Agati
- Department of Pathology, Columbia University Medical Center, New York, NY, USA
| | - Hildo J Lamb
- Department of Radiology, Leiden University Medical Center and Leiden University, Leiden, Netherlands
| | - Drazenka Pongrac Barlovic
- Department of Endocrinology, Diabetes and Metabolism, Ljubljana University Medical Center, Ljubljana, Slovenia
| | - Radovan Hojs
- Department of Nephrology, Clinic for Internal Medicine, University Clinical Centre and Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Manuela Abbate
- IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Clinical Research Center for Rare Diseases "Aldo e Cele Daccò", Ranica, Bergamo, Italy
| | - Rosa Rodriquez
- Department of Pathology, Hospital Universitario de Canarias, Tenerife
| | | | - Esteban Porrini
- Center for Biomedical Research of the Canary Islands (CIBICAN), University of La Laguna, Tenerife, Spain
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23
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Chen Y, Ku H, Zhao L, Wheeler DC, Li LC, Li Q, Varghese Z, Moorhead JF, Powis SH, Huang A, Ruan XZ. Inflammatory stress induces statin resistance by disrupting 3-hydroxy-3-methylglutaryl-CoA reductase feedback regulation. Arterioscler Thromb Vasc Biol 2013; 34:365-76. [PMID: 24233489 DOI: 10.1161/atvbaha.113.301301] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE The risk of cardiovascular disease is increased by up to 33 to 50× in chronic inflammatory states and convention doses of statins may not provide the same cardiovascular protection as in noninflamed patients. This study investigated whether the increase in 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCoA-R)-mediated cholesterol synthesis observed under inflammatory stress was resistant to the action of statins and if so, whether this was because of interference with the sterol regulatory element binding protein cleavage-activating protein pathway. APPROACH AND RESULTS Inflammatory stress was induced by adding cytokines (interleukin-1β, tumor necrosis factor-α, and interleukin-6) and lipopolysaccharides to vascular smooth muscle cells in vitro and by subcutaneous casein injection in apolipoprotein E/scavenger receptors class A/CD36 triple knockout mice in vivo. Inflammatory stress exacerbated cholesterol ester accumulation and was accompanied in vitro and in vivo by increased HMGCoA-R mRNA and protein expression mediated via activation of the sterol regulatory element binding protein cleavage-activating protein/sterol regulatory element binding protein-2 pathway. Atorvastatin reduced HMGCoA-R enzymatic activity and intracellular cholesterol synthesis in vitro. However, inflammatory stress weakened these suppressive effects. Atorvastatin at concentrations of 16 μmol/L inhibited HMGCoA-R activity by 50% in vascular smooth muscle cells, but the same concentration resulted in only 30% of HMGCoA-R activity in vascular smooth muscle cells in the presence of interleukin-1β. Knocking down sterol regulatory element binding protein cleavage-activating protein prevented statin resistance induced by interleukin-1β, and overexpression of sterol regulatory element binding protein cleavage-activating protein induced statin resistance even without inflammatory stress. In vivo, the amount of atorvastatin required to lower serum cholesterol and decrease aortic lipid accumulation rose from 2 to 10 mg/kg per day in the presence of inflammatory stress. CONCLUSIONS Increased cholesterol synthesis mediated by HMGCoA-R under inflammatory stress may be one of the mechanisms for intracellular lipid accumulation and statin resistance.
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Affiliation(s)
- Yaxi Chen
- From the Key Laboratory of Metabolism on Lipid and Glucose, Centre for Lipid Research, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China (Y.C., L.Z., Q.L., A.H., X.Z.R.); Division of Nephrology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan (L.C.L.); and John Moorhead Research Laboratory, Centre for Nephrology, University College London (UCL) Medical School, United Kingdom (H.K., D.C.W., Z.V., J.F.M., S.H.P., X.Z.R.)
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24
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Omran J, Al-Dadah A, Dellsperger KC. Dyslipidemia in patients with chronic and end-stage kidney disease. Cardiorenal Med 2013; 3:165-177. [PMID: 24454313 DOI: 10.1159/000351985] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 05/08/2013] [Indexed: 01/21/2023] Open
Abstract
In this review, we discuss the physiology, diagnosis and treatment of dyslipidemia in patients with chronic and end-stage renal disease. The recent important clinical trials in patients with chronic kidney disease and dyslipidemia are reviewed. Because of the lack of evidence in treating lipid abnormalities in this specific patient population, we propose that future studies should focus on the pathophysiological mechanisms and treatment of dyslipidemia in this special patient population.
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25
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Iriyama N, Yuan B, Yoshino Y, Hatta Y, Horikoshi A, Aizawa S, Takeuchi J, Toyoda H. Aquaporin 9, a promising predictor for the cytocidal effects of arsenic trioxide in acute promyelocytic leukemia cell lines and primary blasts. Oncol Rep 2013; 29:2362-8. [PMID: 23563754 DOI: 10.3892/or.2013.2388] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Accepted: 02/21/2013] [Indexed: 11/06/2022] Open
Abstract
A close correlation between the cytocidal effects of arsenic trioxide (ATO) and aquaporin-9 (AQP9) expression levels has been proposed, yet detailed studies are still needed to confirm this association. Thus, in the present study, the correlation between the expression levels of AQP9 and sensitivity to ATO was investigated using two acute promyelocytic leukemia (APL) cell lines, NB4 and HT93A, as well as primary APL cells from newly diagnosed and relapsed APL patients. A substantially higher sensitivity to ATO-mediated induction of apoptosis was observed in the NB4 cells when compared to that in the HT93A cells. In addition, markedly higher expression levels of AQP9, as assessed using flow cytometry, along with more intracellular arsenic accumulation, were observed in the NB4 cells. More importantly, similar to APL cell lines, the trend of expression levels of AQP9 correlated closely with the differential sensitivity to ATO-mediated induction of apoptosis in primary APL cells. In contrast, no correlation was observed between ATO sensitivity associated with AQP9 expression levels and the expression profiles of cell surface markers as well as chromosomal alterations. These results provide direct evidence that the expression levels of AQP9, rather than other biomarkers such as cell surface markers and chromosomal alterations, correlate closely with the sensitivity to ATO in both APL cell lines and primary blasts. These findings suggest that the AQP9 expression status of APL patients is a predictive marker for the successful outcome of ATO treatment, since AQP9 plays a pivotal role in various arsenite-mediated biological effects on normal and cancer cells. Moreover, flow cytometry may be a new convenient and valuable tool for analyzing the AQP9 status of APL patients compared to current methods such as western blotting.
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Affiliation(s)
- Noriyoshi Iriyama
- Department of Hematology and Rheumatology, Nihon University School of Medicine, Itabashi Hospital, Itabashi-ku, Tokyo 173-8610, Japan
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26
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Sun L, Wen JH, Sun HL, Shu XC, Hu F, Yin DC, Yang Q, Zeng YJ, Sun Y, Liu L. Perindopril attenuates renal tubulointerstitium injury by inhibiting scavenger receptor A over-expression in diabetic rats. J Endocrinol Invest 2012; 35:511-5. [PMID: 21765240 DOI: 10.3275/7867] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Scavenger receptor A (SR-A) is the main receptor through which oxidized LDL (oxLDL) and advanced glycation end products get into the cells. The aim of the present study was to investigate the effect of an ACE inhibitor, perindopril, on the expression of SR-A in renal tubulointerstitium of diabetic rats. Diabetes was induced in male Sprague-Dawley rats by injection with streptozotocin. The rats were then randomly divided into 3 groups: normal control group; untreated diabetes mellitus group; and diabetes mellitus group treated with the ACE inhibitor, perindopril. After a 24-week treatment, tubulointerstitial injury index was assessed on Masson's trichrome sections. The number of macrophages and the expression of SR-A protein in renal tubulointerstitium were detected by immunohistochemistry and the expression of SR-A mRNA was detected by RT-PCR. The tubulointerstitial injury index, the number of macrophages and the expression of SR-A mRNA were significantly higher in the diabetes group than the normal control group. Perindopril treatment not only attenuated the tubulointerstitial injury and the macrophages infiltration but also reduced the overexpression of SR-A mRNA in diabetic rats. The expression of SR-A protein was most obvious in renal tubulointerstitium in diabetic rats, which was attenuated by perindopril treatment. The findings of the present study indicate that perindopril may have renoprotective effects of diabetic nephropathy via inhibiting the expression of SR-A in renal tubulointerstitium.
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MESH Headings
- Angiotensin-Converting Enzyme Inhibitors/therapeutic use
- Animals
- Blotting, Western
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/pathology
- Disease Models, Animal
- Immunoenzyme Techniques
- Kidney Tubules/drug effects
- Kidney Tubules/injuries
- Kidney Tubules/metabolism
- Macrophages/cytology
- Macrophages/drug effects
- Macrophages/metabolism
- Male
- Perindopril/therapeutic use
- RNA, Messenger/genetics
- Rats
- Rats, Sprague-Dawley
- Real-Time Polymerase Chain Reaction
- Reverse Transcriptase Polymerase Chain Reaction
- Scavenger Receptors, Class A/antagonists & inhibitors
- Scavenger Receptors, Class A/genetics
- Scavenger Receptors, Class A/metabolism
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Affiliation(s)
- L Sun
- Department of Endocrinology, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 51900, Guangdong Province, China.
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27
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Xu ZE, Chen Y, Huang A, Varghese Z, Moorhead JF, Yan F, Powis SH, Li Q, Ruan XZ. Inflammatory stress exacerbates lipid-mediated renal injury in ApoE/CD36/SRA triple knockout mice. Am J Physiol Renal Physiol 2011; 301:F713-22. [PMID: 21795641 DOI: 10.1152/ajprenal.00341.2010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Both lipids and inflammation play important roles in the progression of kidney disease. This study was designed to investigate whether inflammation exacerbates lipid accumulation via LDL receptors (LDLr), thereby causing renal injury in C57BL/6J mice, apolipoprotein E (ApoE) knockout (KO) mice, and ApoE/CD36/scavenger receptor A triple KO mice. The mice were given a subcutaneous casein injection to induce inflammatory stress. After 14 wk, terminal blood samples were taken for renal function, lipid profiles, amyloid A (SAA), and IL-6 assays. Lipid accumulation in kidneys was visualized by oil red O staining. Fibrogenic molecule expression in kidneys was examined. There was a significant increase in serum SAA and IL-6 in the all casein-injected mice compared with respective controls. Casein injection reduced serum total cholesterol, LDL cholesterol, and HDL cholesterol and caused lipid accumulation in kidneys from three types of mice. The expression of LDLr and its regulatory proteins sterol-responsive element-binding protein (SREBP) 2 and SREBP cleavage-activating protein (SCAP) were upregulated in inflamed mice compared with controls. Casein injection induced renal fibrosis accompanied by increased expression of fibrogenic molecules in the triple KO mice. These data imply that inflammation exacerbates lipid accumulation in the kidney by diverting lipid from the plasma to the kidney via the SCAP-SREBP2-LDLr pathway and causing renal injury. Low blood cholesterol levels, resulting from inflammation, may be associated with high risk for chronic renal fibrosis.
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Affiliation(s)
- Zhen E Xu
- Centre for Lipid Research, Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Second Affiliated Hospital, Chongqing Medical University, Chongqing, PR China
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28
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Yuan Y, Zhao L, Chen Y, Moorhead JF, Varghese Z, Powis SH, Minogue S, Sun Z, Ruan XZ. Advanced glycation end products (AGEs) increase human mesangial foam cell formation by increasing Golgi SCAP glycosylation in vitro. Am J Physiol Renal Physiol 2011; 301:F236-43. [PMID: 21511699 DOI: 10.1152/ajprenal.00646.2010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Advanced glycation end products (AGEs) is one of the causative factors of diabetic nephropathy, which is associated with lipid accumulation in glomeruli. This study was designed to investigate whether N(ε)-(carboxymethyl) lysine (CML; a member of the AGEs family) increases lipid accumulation by impairing the function of sterol-regulatory element binding protein (SREBP) cleavage-activating protein (SCAP) in human mesangial cells (HMCs). Intracellular cholesterol content was assessed by Oil Red O staining and quantitative assay. The expression of molecules controlling cholesterol homeostasis was examined using real-time quantitative RT-PCR and Western blotting. The activity of Golgi-processing enzymes was determined using enzyme-based methods, and the translocation of SCAP from the endoplasmic reticulum (ER) to the Golgi was detected by confocal microscopy. CML increased cholesterol accumulation in HMCs. Exposure to CML increased expression and abnormal translocation of SCAP from the ER to the Golgi even in the presence of a high concentration of LDL. The increased SCAP translocation carried more SREBP-2 to the Golgi for activation by proteolytic cleavages, enhancing transcription of 3-hydroxy-3-methylclutaryl-CoA reductase and the LDL receptor. CML increased Golgi mannosidase activity, which may enhance glycosylation of SCAP. This prolonged the half-life and enhanced recycling of SCAP between the ER and the Golgi. The effects of CML were blocked by inhibitors of Golgi mannosidases. AGEs (CML) increased lipid synthesis and uptake, thereby causing foam cell formation via increasing transcription and protein glycosylation of SCAP in HMCs. These data imply that inhibitors of Golgi-processing enzymes might have a potential renoprotective role in prevention of mesangial foam cell formation.
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Affiliation(s)
- Yang Yuan
- Dept. of Endocrinology, Zhongda Hospital, Southeast University, No. 87 Dingjiaqiao, Nanjing, Jiangsu Province 21009, P.R. China
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29
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Raimundo M, Lopes JA. Metabolic syndrome, chronic kidney disease, and cardiovascular disease: a dynamic and life-threatening triad. Cardiol Res Pract 2011; 2011:747861. [PMID: 21403897 PMCID: PMC3043294 DOI: 10.4061/2011/747861] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 12/06/2010] [Accepted: 12/24/2010] [Indexed: 01/19/2023] Open
Abstract
The metabolic syndrome (MS) and chronic kidney disease (CKD) have both become global public health problems, with increasing social and economic impact due to their high prevalence and remarkable impact on morbidity and mortality. The causality between MS and CKD, and its clinical implications, still does remain not completely understood. Moreover, prophylactic and therapeutic interventions do need to be properly investigated in this field. Herein, we critically review the existing clinical evidence that associates MS with renal disease and cardiovascular disease, as well as the associated pathophysiologic mechanisms and actual treatment options.
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Affiliation(s)
- Mário Raimundo
- Department of Nephrology and Renal Transplantation, Centro Hospitalar Lisboa Norte, EPE, Hospital de Santa Maria, Avenida Professor Egas Moniz, 1649-035 Lisboa, Portugal
| | - José António Lopes
- Department of Nephrology and Renal Transplantation, Centro Hospitalar Lisboa Norte, EPE, Hospital de Santa Maria, Avenida Professor Egas Moniz, 1649-035 Lisboa, Portugal
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30
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High-calorie diet with moderate protein restriction prevents cachexia and ameliorates oxidative stress, inflammation and proteinuria in experimental chronic kidney disease. Clin Exp Nephrol 2010; 14:536-47. [PMID: 20820841 DOI: 10.1007/s10157-010-0340-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Accepted: 08/02/2010] [Indexed: 10/19/2022]
Abstract
BACKGROUND In earlier studies we found that a high-fat, high-energy diet (HFED) attenuates proteinuria, azotemia and lipid accumulation in the remnant kidney of rats subjected to 5/6 nephrectomy. This study was conducted to explore the mechanism of the salutary effect of HFED in association with moderate protein restriction in this model. METHODS The 5/6 nephrectomized male rats were randomized to receive regular rat chow (CRF group, n = 6) or HFED diet (CRF + HFED, n = 7) for 12 weeks. Sham-operated rats served as controls (n = 6). RESULTS The CRF group exhibited azotemia, hypertension, proteinuria, diminished body weight, oxidative stress, glomerulosclerosis, tubulo-interstitial inflammation and upregulation of pro-oxidant [NAD(P)H oxidase], pro-inflammatory (NF-κB activation, increased MCP-1, lipoxygenase, ICAM-1, VCAM-1), pro-fibrotic (TGF-β, CTGF) and pro-apoptotic pathways (Bax, caspase-3) in the remnant kidney. Consumption of the HFED resulted in a 66% increment in lipid intake, 8% increment in carbohydrate intake and a 24% reduction in protein intake. The CRF + HFED group gained weight normally, had increments in leptin and adiponectin levels, and despite increments in plasma cholesterol and fatty acids, showed significant attenuation of oxidative stress, proteinuria and inflammation, and partial reversal of the remnant kidney upregulation of pro-oxidant, pro-inflammatory, pro-fibrotic and pro-apoptotic pathways. CONCLUSION Consumption of high-energy diet in association with mild protein restriction results in suppression of upregulated pathways that drive progression of renal injury in the remnant kidney model. These findings may have relevance in the management of chronic kidney disease in humans.
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31
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Doi SQ, Chilakamarri GC, Mendonca MC, Araujo M, Nguyen N, Zuhl I, List EO, Kopchick JJ, Hirata MH, Sellitti DF. Increased class A scavenger receptor and glomerular lipid precede mesangial matrix expansion in the bGH mouse model. Growth Horm IGF Res 2010; 20:326-332. [PMID: 20576456 DOI: 10.1016/j.ghir.2010.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Revised: 05/18/2010] [Accepted: 05/24/2010] [Indexed: 10/19/2022]
Abstract
OBJECTIVE Elevated neutral lipid content and mRNA expression of class A scavenger receptor (SRA) have been found in the renal cortex of the bovine growth hormone (bGH) mouse model of progressive glomerulosclerosis (GS). We hypothesize that the increased expression of SRA precedes glomerular scarring in this model. DESIGN Real time RT-PCR and immunofluorescence were employed to measure SRA and collagen types I and IV in the bGH transgenic and control mice at 5 and 12 weeks (wk) of age to determine the chronology of change in SRA expression in relation to glomerular scarring. Alternative mechanisms for increasing glomerular lipid were assessed by measuring mRNA expression levels of low-density lipoprotein receptor (LDL-r), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), and ATP-binding cassette transporter A1 (ABCA1). In addition, the involvement of macrophages in early GS was assessed by CD68 mRNA expression in kidney cortex. RESULTS Both mRNA and protein levels of SRA were significantly increased in 5-wk bGH compared with control mice, whereas the expression of collagen I and IV was unaltered. Unchanged levels of LDL-r and HMGR mRNA indicate that neither regulated cholesterol uptake via LDL-r nor the cholesterol synthetic pathway played a role in the early lipid increase. The finding of increased ABCA1 expression was an indicator of excess intracellular lipid in the renal cortex of bGH mice at 5 wk. CD68 expression in bGH did not differ significantly from that of controls at 5 wk suggesting that cortical macrophage infiltration was not increased in bGH mice at this time point. CONCLUSION An early increase in SRA mRNA and protein expression in the bGH kidney precedes glomerular scarring and is independent of macrophage influx.
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Affiliation(s)
- Sonia Q Doi
- Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
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32
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Abstract
Diabetic nephropathy is an increasingly important cause of morbidity and mortality worldwide. A large body of evidence suggests that dyslipidemia has an important role in the progression of kidney disease in patients with diabetes. Lipids may induce renal injury by stimulating TGF-beta, thereby inducing the production of reactive oxygen species and causing damage to the glomeruli and glomerular glycocalyx. Findings from basic and clinical studies strongly suggest that excess amounts of a variety of lipoproteins and lipids worsens diabetes-associated microvascular and macrovascular disease, increases glomerular injury, increases tubulointerstitial fibrosis, and accelerates the progression of diabetic nephropathy. The increasing prevalence of obesity, type 2 diabetes mellitus, and diabetic nephropathy means that interventions that can interrupt the pathophysiological cascade of events induced by lipoproteins and lipids could enable major life and cost savings. This Review discusses the structural, cellular, and microscopic findings associated with diabetic nephropathy and the influence of lipoproteins, specifically triglyceride-rich lipoproteins (TGRLs), on the development and perpetuation of diabetic nephropathy. Some of the accepted and hypothesized mechanisms of renal injury relating to TGRLs are also described.
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Abstract
The prevalence of metabolic syndrome (MetS) is increasing worldwide in both developing and developed countries. Experimental and clinical studies have revealed that MetS plays an important role in the development of chronic kidney disease (CKD), which leads to end-stage renal disease. Emerging evidence also suggests that CKD may actually cause MetS since the kidney is an important organ of glucose and lipid homeostasis. Although multiple mechanisms have been shown to be involved in the pathogenesis of MetS, insulin resistance appears to be a central pathophysiological factor contributing to MetS. In this review we will discuss the association of MetS with insulin resistance and CKD, and the renal pathophysiological changes associated with MetS.
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Affiliation(s)
- Xiongzhong Ruan
- Centre for Lipid Research, Chongqing Medical University, Chongqing, China
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34
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Abstract
When the 'lipid nephrotoxicity hypothesis' was proposed in 1982, it brought together several disparate experimental findings in hyperlipidemia and renal disease to suggest that concomitant hyperlipidemia and proteinuria would cause self-perpetuating renal disease once the initial glomerular insult was no longer present. This process would be analogous to atherosclerosis. Since 1982, increasing evidence has supported the hypothesis that lipid abnormalities contribute to both atherosclerosis and glomerulosclerosis. In this Review, we discuss research developments that are relevant to the lipid nephrotoxicity hypothesis. We describe how inflammatory stress accompanying chronic kidney disease modifies lipid homeostasis by increasing cholesterol uptake mediated by lipoprotein receptors, inhibiting cholesterol efflux mediated by the ATP-binding cassette transporter 1 and impairing cholesterol synthesis in peripheral cells. As a result of these events, cholesterol relocates to and accumulates in renal, vascular, hepatic and possibly other tissues. The combination of increased cellular cholesterol influx and reduced efflux causes injury in some tissues and lowers the plasma cholesterol level. In addition, inflammatory stress causes a degree of statin resistance via unknown mechanisms. These phenomena alter traditional understanding of the pathogenesis of lipid-mediated renal and vascular injury and could influence the clinical evaluation of renal and cardiovascular risk and the role of lipid-lowering treatment in affected patients.
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Affiliation(s)
- Xiong Z Ruan
- Centre for Nephrology, University College London Medical School, Royal Free Campus, London, UK.
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Identification of trichostatin A as a novel transcriptional up-regulator of scavenger receptor BI both in HepG2 and RAW 264.7 cells. Atherosclerosis 2009; 204:127-35. [DOI: 10.1016/j.atherosclerosis.2008.08.041] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Revised: 08/23/2008] [Accepted: 08/26/2008] [Indexed: 12/17/2022]
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Ishigaki N, Yamamoto T, Shimizu Y, Kobayashi K, Yatoh S, Sone H, Takahashi A, Suzuki H, Yamagata K, Yamada N, Shimano H. Involvement of glomerular SREBP-1c in diabetic nephropathy. Biochem Biophys Res Commun 2007; 364:502-8. [PMID: 17961514 DOI: 10.1016/j.bbrc.2007.10.038] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2007] [Accepted: 10/07/2007] [Indexed: 01/11/2023]
Abstract
The role of glomerular SREBP-1c in diabetic nephropathy was investigated. PEPCK-promoter transgenic mice overexpressing nuclear SREBP-1c exhibited enhancement of proteinuria with mesangial proliferation and matrix accumulation, mimicking diabetic nephropathy, despite the absence of hyperglycemia or hyperlipidemia. Isolated transgenic glomeruli had higher expression of TGFbeta-1, fibronectin, and SPARC in the absence of marked lipid accumulation. Gene expression of P47phox, p67phox, and PU.1 were also activated, accompanying increased 8-OHdG in urine and kidney, demonstrating that glomerular SREBP-1c could directly cause oxidative stress through induced NADPH oxidase. Similar changes were observed in STZ-treated diabetic mice with activation of endogenous SREBP-1c. Finally, diabetic proteinuria and oxidative stress were ameliorated in SREBP-1-null mice. Adenoviral overexpression of active and dominant-negative SREBP-1c caused consistent reciprocal changes in expression of both profibrotic and oxidative stress genes in MES13 mesangial cells. These data suggest that activation of glomerular SREBP-1c could contribute to emergence and/or progression of diabetic nephropathy.
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Affiliation(s)
- Naomi Ishigaki
- Department of Internal Medicine (Endocrinology and Metabolism), Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
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Ma KL, Ruan XZ, Powis SH, Moorhead JF, Varghese Z. Anti-atherosclerotic effects of sirolimus on human vascular smooth muscle cells. Am J Physiol Heart Circ Physiol 2007; 292:H2721-8. [PMID: 17322416 DOI: 10.1152/ajpheart.01174.2006] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Sirolimus is a potent immunosuppressive agent and has an anti-atherosclerotic effect through its anti-proliferative property. The present study was undertaken to investigate the effect of sirolimus on intracellular cholesterol homeostasis in human vascular smooth muscle cells (VSMCs) in the presence of inflammatory cytokine IL-1β. We explored the effect of sirolimus on the lipid accumulation of VSMCs in the presence of IL-1β, using Oil Red O staining and quantitative measurement of intracellular cholesterol. The effect of sirolimus on the gene and protein expression of lipoprotein receptors and ATP binding cassettes (ABCA1 and ABCG1) was examined by real-time PCR and Western blotting, respectively. Furthermore, the effect of sirolimus on cholesterol efflux from VSMCs in the presence or absence of IL-1β was also investigated using [3H] cholesterol efflux. Finally, we examined the effect of sirolimus on the production of inflammatory cytokines in VSMCs using ELISA. Sirolimus reduced intracellular lipid accumulation in VSMCs mediated by IL-1β possibly due to the reduction of expression of low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) receptors. Sirolimus increased cholesterol efflux from VSMCs and overrode the suppression of cholesterol efflux induced by IL-1β. Sirolimus also increased ABCA1 and ABCG1 genes expression, even in the presence of IL-1β. We further confirmed that sirolimus inhibited mRNA and protein expression of inflammatory cytokines IL-6, tumor necrosis factor-α, IL-8, and monocyte chemoattractant protein-1. Inhibition of lipid uptake together with increasing cholesterol efflux and the inhibition of inflammatory cytokines are all important aspects of the anti-atherosclerotic effects of sirolimus on VSMCs.
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MESH Headings
- ATP Binding Cassette Transporter 1
- ATP Binding Cassette Transporter, Subfamily G, Member 1
- ATP-Binding Cassette Transporters/genetics
- ATP-Binding Cassette Transporters/metabolism
- Atherosclerosis/genetics
- Atherosclerosis/metabolism
- Atherosclerosis/prevention & control
- Azo Compounds
- Cardiovascular Agents/pharmacology
- Cardiovascular Agents/therapeutic use
- Cells, Cultured
- Cholesterol/metabolism
- Coloring Agents
- Coronary Vessels/cytology
- Coronary Vessels/drug effects
- Coronary Vessels/metabolism
- Cytokines/genetics
- Cytokines/metabolism
- Dose-Response Relationship, Drug
- Gene Expression/drug effects
- Homeostasis/drug effects
- Humans
- Inflammation/genetics
- Inflammation/metabolism
- Inflammation/prevention & control
- Interleukin-1beta/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- RNA, Messenger/metabolism
- Receptors, LDL/genetics
- Receptors, LDL/metabolism
- Sirolimus/pharmacology
- Sirolimus/therapeutic use
- Staining and Labeling/methods
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Affiliation(s)
- Kun L Ma
- Centre for Nephrology, Royal Free & Univ. College Medical School, University College London, London, UK
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Okamura DM, López-Guisa JM, Koelsch K, Collins S, Eddy AA. Atherogenic scavenger receptor modulation in the tubulointerstitium in response to chronic renal injury. Am J Physiol Renal Physiol 2007; 293:F575-85. [PMID: 17537985 DOI: 10.1152/ajprenal.00063.2007] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Oxidized low-density lipoproteins (oxLDL) and their scavenger receptor (SR) binding partners play a central role in atherosclerosis and by analogy may play a role in chronic kidney disease pathogenesis. The present study was designed to investigate in C57BL/6 mice the effects of hypercholesterolemia on renal injury severity and oxLDL generation after unilateral ureteral obstruction (UUO). The expression profiles of CD36, SR class AI/II (SR-A), lectin-like receptor for oxidized low-density lipoprotein-1 (Lox-1), and SR that binds phosphatidylserine and oxLDL (SR-PSOX/CXCL16) were examined. Four experimental groups were studied: sham and UUO male mice on either a high-fat Western diet or a control diet. Significantly more oxLDL accumulated in the tubulointerstitium of hypercholesterolemic mice compared with normocholesterolemic mice after 14 days of UUO (P < 0.01). Total kidney collagen was significantly higher in the obstructed kidneys of hypercholesterolemic mice compared with normocholesterolemic mice on day 14 (P < 0.01). After 14 days of obstruction, the number of interstitial F4/80+ macrophages and NF-kappaB activation increased in hypercholesterolemic mice compared with normocholesterolemic mice (P < 0.01). In normal kidneys, CD36, SR-A, Lox-1, and CXCL16 were primarily localized to renal tubular epithelia. After ureteral obstruction, CD36 increased at day 7; SR-A and Lox-1 progressively decreased in a time-dependent manner; and CXCL16 increased significantly with the onset of obstruction (P < 0.01). Strong tubular expression suggests that in addition to inflammatory interstitial cells, renal tubular scavenger receptors may help to orchestrate the inflammatory and fibrogenic pathways that are activated by oxLDL.
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MESH Headings
- Amino Acid Oxidoreductases/metabolism
- Animals
- Atherosclerosis/physiopathology
- Blotting, Northern
- Blotting, Western
- Chemokine CXCL16
- Chemokine CXCL6
- Chemokines, CXC/metabolism
- Collagen/metabolism
- Diet, Atherogenic
- Fibrosis/pathology
- Hypercholesterolemia/blood
- Immunohistochemistry
- Kidney/metabolism
- Kidney/pathology
- Kidney Failure, Chronic/pathology
- Lipoproteins, LDL/metabolism
- Macrophages/pathology
- Male
- Mice
- Mice, Inbred C57BL
- NF-kappa B/metabolism
- Nephritis, Interstitial/pathology
- Receptors, Complement 3b/physiology
- Receptors, Oxidized LDL/metabolism
- Receptors, Scavenger/metabolism
- Receptors, Scavenger/physiology
- Scavenger Receptors, Class A/metabolism
- Ureteral Obstruction/complications
- Ureteral Obstruction/physiopathology
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Affiliation(s)
- Daryl M Okamura
- Children's Hospital and Regional Medical Center, Department of Pediatrics, University of Washington, 4800 Sand Point Way NE, Seattle WA 98015, USA.
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Mathis AS, Jin S, Friedman GS, Peng F, Carl SM, Knipp GT. The Pharmacodynamic Effects of Sirolimus andSirolimus-Calcineurin Inhibitor Combinations on Macrophage Scavenger and Nuclear Hormone Receptors. J Pharm Sci 2007; 96:209-22. [PMID: 17016853 DOI: 10.1002/jps.20751] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Sirolimus (SIR) alone or in combination with cyclosporine (CsA) or tacrolimus (TAC) are used in solid organ transplantation, but uncertainty remains regarding their respective atherogenic potentials. METHODS THP-1 cells were cultured as macrophages and then treated with plasma trough and peak concentration doses of SIR, SIR/CsA or SIR/TAC to assess the time- and dose-dependent mRNA or protein expression of selected atherogenic genes. The selected atherogenic genes included: the macrophage scavenger receptors (MSRs) CD36, CD68, scavenger receptor (SR)-A, SR-BII, and LOX-1; the nuclear hormone receptors peroxisome proliferator activated receptor gamma (PPARgamma) and liver-X-receptor alpha (LXRalpha); and the cholesterol efflux transporter (ABCA-1). RESULTS SIR-mediated changes in mRNA included the upregulation of ABCA1, downregulation of CD68, SR-A and SR-BII, and concentration- and/or time-dependent effects on CD36, LOX-1, PPARgamma, and LXRalpha that did not translate into significant protein changes. With SIR/CsA, the protein expressions of PPARgamma and ABCA-1 were downregulated at 8 h. In contrast, with SIR/TAC, PPARgamma, and ABCA-1 protein expressions were upregulated at 8 h. CONCLUSIONS Combination results differed from findings with SIR alone, supporting the observed clinical phenotype with calcineurin inhibitors. These findings may provide a rationale for the development of novel drug delivery strategies to mitigate adverse pharmacodynamic responses.
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Affiliation(s)
- A Scott Mathis
- Department of Pharmacy, Saint Barnabas Medical Center, 94 Old Short Hills Road, Livingston, New Jersey 07039, USA
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40
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Sarafidis PA, Bakris GL. Protection of the kidney by thiazolidinediones: An assessment from bench to bedside. Kidney Int 2006; 70:1223-33. [PMID: 16883325 DOI: 10.1038/sj.ki.5001620] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The global epidemic of diabetes mellitus has led to a continuous increase in the prevalence of diabetic nephropathy over the past years. Thus, diabetic nephropathy is currently the number one cause of end-stage renal disease in the Western world. It represents a major public health problem for which more effective prevention and treatment strategies are needed. Thiazolidinediones (TZDs) are a class of agents that lower blood glucose through reduction of insulin resistance in patients with type 2 diabetes. Growing evidence support the concept that TZDs have several beneficial effects on the cardiovascular system beyond their effects on glycemic control. These benefits include: blood pressure lowering, triglyceride reduction, high-density lipoprotein-cholesterol elevation, and reduction in subclinical vascular inflammation. Moreover, data from several animal and human studies support the notion that TZDs reduce urine albumin excretion and may prevent development of renal injury. The relative lack of evidence, however, demonstrating the effects of TZDs on hard renal outcomes mandates the need for well-designed trials with this particular objective. This paper summarizes all the data from clinical and experimental studies relevant to a possible renoprotective effect of TZDs and discusses actions of these compounds that may contribute toward this effect.
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Affiliation(s)
- P A Sarafidis
- Department of Preventive Medicine, Hypertension/Clinical Research Center, Rush University Medical Center, Chicago, Illinois 60612, USA
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41
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Fragopoulou E, Iatrou C, Antonopoulou S, Ruan XZ, Fernando RL, Powis SH, Moorhead JF, Varghese Z. Platelet-activating factor (PAF) increase intracellular lipid accumulation by increasing both LDL and scavenger receptors in human mesangial cells. ACTA ACUST UNITED AC 2006; 147:281-9. [PMID: 16750665 DOI: 10.1016/j.lab.2006.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2005] [Revised: 01/24/2006] [Accepted: 01/25/2006] [Indexed: 11/28/2022]
Abstract
Intra- and extracellular lipid accumulation and the production of inflammatory mediators by renal and accessory cells may play an important role in the initiation and progression of these lesions. Platelet activating factor (PAF) is a biologically active phospholipid that is produced by various cells upon activation by different stimuli. It has been suggested that PAF plays a role in atherogenesis, and several studies indicated its participation in the pathogenesis of renal diseases. The aim of this study is to investigate the role of PAF on intracellular lipid accumulation and gene regulation of lipoprotein receptors in human mesangial cells (HMCs). A human mesangial cell line (HMC) was used to study the effects of PAF on foam cell formation by Oil red O staining and on the expression of LDLr, SR-AI, and PAF-R mRNA using RT-PCR. Native LDL caused foam cell formation in HMC in the presence of PAF. PAF enhanced LDLr expression and overrode LDL receptor suppression induced by a high concentration of LDL. Moreover, it enhanced SR-AI expression. PAF also caused increase in PAF-R expression. The above data suggest that PAF enhances its own receptor expression and then increases lipid accumulation by dysregulating LDL receptor regulation and inducing scavenger receptor expression in HMCs. These results suggest that PAF has a potential role in lipid mediated renal injury.
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MESH Headings
- Cell Line, Transformed
- Cholesterol, LDL/pharmacokinetics
- Foam Cells/cytology
- Foam Cells/metabolism
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/physiology
- Glomerulosclerosis, Focal Segmental/metabolism
- Glomerulosclerosis, Focal Segmental/physiopathology
- Humans
- Lipid Metabolism/drug effects
- Lipid Metabolism/physiology
- Mesangial Cells/cytology
- Mesangial Cells/drug effects
- Mesangial Cells/metabolism
- Platelet Activating Factor/metabolism
- Platelet Activating Factor/pharmacology
- Platelet Membrane Glycoproteins/genetics
- Platelet Membrane Glycoproteins/metabolism
- RNA, Messenger/analysis
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, LDL/genetics
- Receptors, LDL/metabolism
- Scavenger Receptors, Class A/genetics
- Scavenger Receptors, Class A/metabolism
- Tritium
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Affiliation(s)
- Elizabeth Fragopoulou
- Faculty of Chemistry, National and Kapodistrian University of Athens, Athens, Greece
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42
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Machado MO, Hirata RDC, Sellitti DF, Iotti R, Iotti A, Cusumano AM, Riordan GP, Coschigano KT, Kopchick JJ, Zuhl I, Nguyen N, Hirata MH, Doi SQ. Growth hormone promotes glomerular lipid accumulation in bGH mice. Kidney Int 2006; 68:2019-28. [PMID: 16221202 DOI: 10.1111/j.1523-1755.2005.00656.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Bovine growth hormone (bGH) transgenic mice develop progressive glomerulosclerosis and exhibit abnormalities in hepatic lipid metabolism. We have previously shown that growth hormone up-regulates the low-density lipoprotein (LDL) receptor and 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) in mouse mesangial cells. However, a role of lipid abnormalities in bGH kidney disease has not yet been demonstrated. METHODS Groups of bGH mice (5 and 11 months old) presenting with, respectively, moderate and severe degrees of glomerulosclerosis were compared to age-matched controls. Neutral lipid content in kidney cortex was determined by oil red-O staining, serum cholesterol, and triglycerides by enzymatic assays, relative mRNA expression of LDL receptors, HMGR, and scavenger receptor by real-time reverse transcription-polymerase chain reaction (RT-PCR), and HMGR protein expression by immunoblotting. Two younger (5 and 12 weeks old) groups of mice were used to study scavenger receptor expression at earlier time points. RESULTS Serum cholesterol was significantly increased in bGH mice at 5 months, but triglycerides were lower than control levels at both 5 and 11 months. Renal cortex HMGR expression was elevated at the mRNA but not at the protein level in the 11-month-old bGH group compared to controls. However, glomerular neutral lipid staining and scavenger receptor mRNA expression were markedly increased in all bGH mice, including those at 5 weeks of age compared to respective controls. CONCLUSION The bGH mouse exhibits an increased mesangial lipid content and elevated scavenger receptor mRNA expression as early as at 5 weeks of age, suggesting that an increased kidney uptake of oxidized LDL could play a role in the development of glomerulosclerosis in this mouse model.
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Bohlender JM, Franke S, Stein G, Wolf G. Advanced glycation end products and the kidney. Am J Physiol Renal Physiol 2005; 289:F645-59. [PMID: 16159899 DOI: 10.1152/ajprenal.00398.2004] [Citation(s) in RCA: 272] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Advanced glycation end products (AGEs) are a heterogeneous group of protein and lipids to which sugar residues are covalently bound. AGE formation is increased in situations with hyperglycemia (e.g., diabetes mellitus) and is also stimulated by oxidative stress, for example in uremia. It appears that activation of the renin-angiotensin system may contribute to AGE formation through various mechanisms. Although AGEs could nonspecifically bind to basement membranes and modify their properties, they also induce specific cellular responses including the release of profibrogenic and proinflammatory cytokines by interacting with the receptor for AGE (RAGE). However, additional receptors could bind AGEs, adding to the complexity of this system. The kidney is both: culprit and target of AGEs. A decrease in renal function increases circulating AGE concentrations by reduced clearance as well as increased formation. On the other hand, AGEs are involved in the structural changes of progressive nephropathies such as glomerulosclerosis, interstitial fibrosis, and tubular atrophy. These effects are most prominent in diabetic nephropathy, but they also contribute to renal pathophysiology in other nondiabetic renal diseases. Interference with AGE formation has therapeutic potential for preventing the progression of chronic renal diseases, as shown from data of animal experiments and, more recently, the first clinical trials.
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Affiliation(s)
- Jürgen M Bohlender
- Klinik für Innere Medizin III, Universitätsklinik Jena, Erlanger Allee 101, Jena, Germany.
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Berfield AK, Chait A, Oram JF, Zager RA, Johnson AC, Abrass CK. IGF-1 induces rat glomerular mesangial cells to accumulate triglyceride. Am J Physiol Renal Physiol 2005; 290:F138-47. [PMID: 16077083 DOI: 10.1152/ajprenal.00054.2005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Rat glomerular mesangial cells (MC) become lipid-laden foam cells when they are exposed to IGF-1. IGF-1 increased accumulation of triglyceride (TG) 2.5-fold in MC after 7 days. TG accumulation resulted from enhanced macropinocytosis and decreased efflux secondary to a 40-50% reduction in peroxisome proliferator-activated receptor (PPAR)-delta (PPARdelta). There was no evidence of primary or secondary changes in cholesterol or TG synthesis, increased uptake by LDL or scavenger receptors, or reduced efflux via ATP-binding cassette A-1. Although the lipid moiety taken up can be influenced by the concentration of cholesterol or TG in the medium, in standard medium MC preferentially accumulate TG. TG-rich MC foam cells fail to contract in response to angiotensin II (Berfield AK, Andress DL, and Abrass CK. Kidney Int 62: 1229-1237, 2002); however, their migratory response to IGF binding protein-5 is unaffected. This differs from cholesterol loading, which impairs both phagocytosis and migration. These findings have important implications for understanding the mechanisms that contribute to lipid accumulation in MC and the functional consequences of different forms of foam cells. These observations are relevant to understanding vascular disease and progressive renal diseases that are accelerated by abnormalities in lipid metabolism.
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Affiliation(s)
- Anne K Berfield
- Univ. of Washington School of Medicine and Department of Medicine, Veterans Affairs Puget Sound Health Care System, 1660 South Columbian Way, Seattle, WA 98108, USA
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Varghese Z, Fernando R, Moorhead JF, Powis SH, Ruan XZ. Effects of sirolimus on mesangial cell cholesterol homeostasis: a novel mechanism for its action against lipid-mediated injury in renal allografts. Am J Physiol Renal Physiol 2005; 289:F43-8. [PMID: 15769938 DOI: 10.1152/ajprenal.00181.2004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Lipoprotein abnormalities are present in a high proportion of renal transplant patients. It is accepted that dyslipidemia is associated with atherosclerosis and in the progression of renal disease. Lipid abnormalities may also play a significant role in the development of chronic allograft nephropathy. Sirolimus was found to have an antiatherosclerotic effect in the apolipoprotein E-knockout mice model of hyperlipidemia through its antiproliferative effects. As lipid-mediated renal injury is important in the pathogenesis of glomerulosclerosis which shares common pathogenic mechanisms with atherosclerosis, in this study we have tested the hypothesis that sirolimus prevents lipid-mediated renal injury through the modulation of cholesterol homeostasis of mesangial cells and its anti-inflammatory effects on macrophages. We demonstrated that sirolimus reduced lipid accumulation, as measured by oil red O staining in human mesangial cells (HMCs). Using real-time PCR, we screened the mRNA expression of lipoprotein receptors. Sirolimus significantly suppressed LDL and VLDL receptors and CD36 gene expression. It also increased cholesterol efflux from HMCs by increasing peroxisome proliferator-activated receptor-α (PPARα), PPARγ, liver X receptor-α, and ATP binding cassette A1 (ABCA1) gene expression. Sirolimus overrode the suppression of cholesterol efflux and ABCA1 gene expression induced by the inflammatory cytokine IL-1β. Furthermore, sirolimus significantly inhibited inflammatory cytokines IL-6 and TNF-α production in macrophages. These data suggest that sirolimus may prevent cellular cholesterol accumulation even in the presence of hyperlipidemia and inflammation, by regulating both cholesterol homeostasis and inflammatory responses.
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Affiliation(s)
- Zac Varghese
- Centre for Nephrology, Royal Free and University College Medical School, London NW3 2PF, UK.
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Dan Q, Wong RLC, Yin S, Chung SK, Chung SSM, Lam KSL. Interaction between the Polyol Pathway and Non-Enzymatic Glycation on Mesangial Cell Gene Expression. ACTA ACUST UNITED AC 2004; 98:e89-99. [PMID: 15528949 DOI: 10.1159/000080684] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2004] [Accepted: 06/14/2004] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Both activation of the polyol pathway and enhanced non-enzymatic glycation have been implicated in the pathogenesis of diabetic glomerulopathy. We investigated the interaction between these two pathways using normal mesangial cells (MCs) and transgenic (TG) MCs with elevated aldose reductase (AR) activity. METHODS TG mice with expression of the human AR (hAR) gene in kidney MCs were established. Mouse glomeruli and primary cultures of MCs from hAR TG and wild-type (WT) mice were studied regarding the changes in AR activity, transforming growth factor-beta1 (TGF-beta1) and type IV collagen mRNA and protein levels, in response to BSA modified by advanced glycation end-products (AGE-BSA). RESULTS Ex vivo addition of AGE-BSA increased AR activity, TGF-beta1 and type IV collagen mRNA levels in both WT and TG glomeruli, with greater rise in TG glomeruli. These increments were attenuated by zopolrestat, an AR inhibitor. In cultured MCs, AGE-BSA enhanced AR activity, TGF-beta(1) and type IV collagen mRNA and protein levels both in WT and TG MCs, again with greater increases in TG MCs. The AGE-induced enhancement in TGF-beta1 and type IV collagen expression were suppressed by either zopolrestat or transfection with an AR antisense oligonucleotide. CONCLUSION These data suggest that the activation of the polyol pathway by AGEs, more marked in genetic conditions with increased AR activity, may contribute to the pathogenesis of diabetic glomerulopathy, through enhancing mesangial cell expression of TGF-beta1 and type IV collagen.
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Affiliation(s)
- Qinghong Dan
- Department of Medicine, The University of Hong Kong, Hong Kong, PR China
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47
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Ruan XZ, Moorhead JF, Fernando R, Wheeler DC, Powis SH, Varghese Z. PPAR agonists protect mesangial cells from interleukin 1beta-induced intracellular lipid accumulation by activating the ABCA1 cholesterol efflux pathway. J Am Soc Nephrol 2003; 14:593-600. [PMID: 12595494 DOI: 10.1097/01.asn.0000050414.52908.da] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Previous studies have demonstrated that inflammatory cytokines such as interleukin-1beta (IL-1beta) promote lipid accumulation in human mesangial cells (HMC) by dysregulating the expression of lipoprotein receptors. Intracellular lipid accumulation is governed by both influx and efflux; therefore, the effect of IL-1beta on the efflux of lipid from HMC was investigated. IL-1beta was shown to inhibit (3)H-cholesterol efflux from HMC and increase total intracellular cholesterol concentration, probably as a result of reduced expression of the adenosine triphosphate (ATP) binding cassette A1 (ABCA1), a transporter protein involved in apolipoprotein-A1 (apo-A1)-mediated lipid efflux. To ascertain the molecular mechanisms involved, expression of peroxisome proliferator-activated receptors (PPAR) and liver X receptoralpha (LXRalpha) were examined. IL-1beta (5 ng/ml) reduced PPARalpha, PPARgamma, and LXRalpha mRNA expression. Activation of PPARgamma with the agonist prostaglandin J2 (10 micro M) and of PPARalpha with either bezafibrate (100 micro M) or Wy14643 (100 micro M) both increased LXRalpha and ABCA1 gene expression also and enhanced apoA1-mediated cholesterol efflux from lipid-loaded cells, even in the presence of IL-1beta. A natural ligand of LXRalpha, 25-hydroxycholesterol (25-OHC), had similar effects; when used together with PPAR agonists, an additive effect was observed, indicating co-operation between PPAR and LXRalpha in regulating ABCA1 gene expression. This was supported by the observation that overexpression of either PPARalpha or PPARgamma by transfection enhanced LXRalpha and ABCA1 gene induction by PPAR agonists. Taken together with previous data, it appears that, in addition to increasing lipid uptake, inflammatory cytokines promote intracellular lipid accumulation by inhibiting cholesterol efflux through the PPAR-LXRalpha-ABCA1 pathway. These results suggest potential mechanisms whereby inflammation may exacerbate lipid-mediated cellular injury in the glomerulus and in other tissues and indicate that PPAR agonists may have a protective effect.
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Affiliation(s)
- Xiong Z Ruan
- Centre for Nephrology, Royal Free and University College Medical School, London, United Kingdom
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48
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Johnson ACM, Yabu JM, Hanson S, Shah VO, Zager RA. Experimental glomerulopathy alters renal cortical cholesterol, SR-B1, ABCA1, and HMG CoA reductase expression. THE AMERICAN JOURNAL OF PATHOLOGY 2003; 162:283-91. [PMID: 12507911 PMCID: PMC1851117 DOI: 10.1016/s0002-9440(10)63819-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/30/2002] [Indexed: 11/16/2022]
Abstract
Previous studies indicate that acute tubular injury causes free cholesterol (FC) and cholesteryl ester (CE) accumulation within renal cortex/proximal tubules. This study assessed whether similar changes occur with glomerulopathy/nephrotic syndrome, in which high-circulating/filtered lipoprotein levels increase renal cholesterol supply. Potential adaptive changes in cholesterol synthetic/transport proteins were also assessed. Nephrotoxic serum (NTS) or passive Heymann nephritis (PHN) was induced in Sprague-Dawley rats. Renal injury (blood urea nitrogen, proteinuria) was assessed 2 and 7 days (NTS), or 10 and 30 days (PHN) later. FC and CE levels in renal cortex, isolated glomeruli, and proximal tubule segments were determined. SR-B1 (a CE influx protein), ABCA1 (a FC exporter), and HMG CoA reductase protein/mRNA levels were also assessed. FC was minimally elevated in renal cortex (0 to 15%), the majority apparently localizing to proximal tubules. More dramatic CE elevations were found ( approximately 5 to 15x), correlating with the severity of proteinuria at any single time point (r >/= 0.85). Cholesterol increments were associated with decreased SR-B1, increased ABCA1, and increased HMG CoA reductase (HMGCR) protein and its mRNA. Tubule (HK-2) cell culture data indicated that SR-B1 and ABCA1 levels are responsive to cholesterol supply. Experimental nephropathy can increase renal FC, and particularly CE, levels, most notably in proximal tubules. These changes are associated with adaptations in SR-B1 and ABCA1 expression, which are physiologically appropriate changes for a cholesterol overload state. However, HMGCR protein/mRNA increments can also result. These seem to reflect a maladaptive response, potentially contributing to a cell cholesterol overload state.
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MESH Headings
- ATP Binding Cassette Transporter 1
- ATP-Binding Cassette Transporters/metabolism
- Animals
- Blotting, Western
- CD36 Antigens/metabolism
- Cell Line
- Cholesterol/metabolism
- Cholesterol Esters/metabolism
- Disease Models, Animal
- Disease Progression
- Glomerulonephritis/metabolism
- Glomerulonephritis/pathology
- Humans
- Hydroxymethylglutaryl CoA Reductases/genetics
- Hydroxymethylglutaryl CoA Reductases/metabolism
- Kidney Cortex/metabolism
- Kidney Cortex/pathology
- Kidney Function Tests
- Kidney Tubules, Proximal/cytology
- Kidney Tubules, Proximal/metabolism
- Male
- Membrane Proteins
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Immunologic
- Receptors, Lipoprotein
- Receptors, Scavenger
- Scavenger Receptors, Class B
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Affiliation(s)
- Ali C M Johnson
- Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
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49
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Abstract
Accelerated atherosclerosis is often observed in patients with chronic renal failure. In the present review we summarize and discuss the recent literature on the pathogenic role of low-density lipoproteins modified by oxidative processes in atherosclerosis and the possible role in renal diseases. Pathogenetically, the oxidation of low-density lipoproteins is considered to be a key event in the development of atherosclerosis, in part by causing enhanced uptake of lipids by macrophages. In addition, oxidation of low-density lipoproteins exerts cytotoxic, proinflammatory and immunogenic properties, all of which could potentially contribute to the development and progression of atherosclerosis.
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Affiliation(s)
- Peter Heeringa
- Department of Clinical and Experimental Immunology, Cardiovascular Research Institute Maastricht, Maastricht University, The Netherlands.
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50
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Berfield AK, Abrass CK. IGF-1 induces foam cell formation in rat glomerular mesangial cells. J Histochem Cytochem 2002; 50:395-403. [PMID: 11850441 DOI: 10.1177/002215540205000310] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
When rat glomerular mesangial cells (MCs) are cultured with IGF-1 they accumulate intracellular lipid and take on foam cell morphology. These changes were characterized by electron microscopy and Nile red staining. To define the mechanism responsible for IGF-1-mediated lipid uptake, MCs were evaluated for endocytosis, scavenger receptor activity, and receptor-mediated uptake by the LDL receptor. Lipid accumulation was markedly increased when MCs were cultured with IGF. The primary route of uptake was through enhanced endocytosis. Lipid-laden MCs have decreased phagocytic capacity and disrupted cytoskeletons. These data show that IGF-1 induces MC to take on a foam cell morphology and that lipid-laden MCs have impaired phagocytic function.
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Affiliation(s)
- Anne K Berfield
- Veteran Affairs Puget Sound Health Care System, Seattle, Washington 98108, USA
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