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Kang JM, Lee HS, Kim J, Yang DH, Jeong HY, Lee YH, Kim DJ, Park SH, Sung M, Kim J, An HJ, Lee SH, Lee SY. Beneficial Effect of Chloroquine and Amodiaquine on Type 1 Diabetic Tubulopathy by Attenuating Mitochondrial Nox4 and Endoplasmic Reticulum Stress. J Korean Med Sci 2020; 35:e305. [PMID: 32924342 PMCID: PMC7490204 DOI: 10.3346/jkms.2020.35.e305] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 07/20/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Oxidative stress induced by chronic hyperglycemia is recognized as a significant mechanistic contributor to the development of diabetic kidney disease (DKD). Nonphagocytic nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) is a major source of reactive oxygen species (ROS) in many cell types and in the kidney tissue of diabetic animals. We designed this study to explore the therapeutic potential of chloroquine (CQ) and amodiaquine (AQ) for inhibiting mitochondrial Nox4 and diabetic tubular injury. METHODS Human renal proximal tubular epithelial cells (hRPTCs) were cultured in high-glucose media (30 mM D-glucose), and diabetes was induced with streptozotocin (STZ, 50 mg/kg i.p. for 5 days) in male C57BL/6J mice. CQ and AQ were administered to the mice via intraperitoneal injection for 14 weeks. RESULTS CQ and AQ inhibited mitochondrial Nox4 and increased mitochondrial mass in hRPTCs under high-glucose conditions. Reduced mitochondrial ROS production after treatment with the drugs resulted in decreased endoplasmic reticulum (ER) stress, suppressed inflammatory protein expression and reduced cell apoptosis in hRPTCs under high-glucose conditions. Notably, CQ and AQ treatment diminished Nox4 activation and ER stress in the kidneys of STZ-induced diabetic mice. In addition, we observed attenuated inflammatory protein expression and albuminuria in STZ-induced diabetic mice after CQ and AQ treatment. CONCLUSION We substantiated the protective actions of CQ and AQ in diabetic tubulopathy associated with reduced mitochondrial Nox4 activation and ER stress alleviation. Further studies exploring the roles of mitochondrial Nox4 in the pathogenesis of DKD could suggest new therapeutic targets for patients with DKD.
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Affiliation(s)
- Jun Mo Kang
- Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Hyun Seob Lee
- Genomics Core Facility, Department of Transdisciplinary Research and Collaboration, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Junghyun Kim
- Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Dong Ho Yang
- Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Hye Yun Jeong
- Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Yu Ho Lee
- Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Dong Jin Kim
- Department of Internal Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, Seoul, Korea
| | - Seon Hwa Park
- Department of Internal Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, Seoul, Korea
| | - MinJi Sung
- Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Jaehee Kim
- Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Hyun Ju An
- Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea
| | - Sang Ho Lee
- Department of Internal Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, Seoul, Korea.
| | - So Young Lee
- Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
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Ruan Q, Lu H, Zhu H, Guo Y, Bai Y. A network-regulative pattern in the pathogenesis of kidney injury following severe acute pancreatitis. Biomed Pharmacother 2020; 125:109978. [DOI: 10.1016/j.biopha.2020.109978] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 01/17/2020] [Accepted: 01/27/2020] [Indexed: 01/04/2023] Open
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3
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Xiao YH, He XY, Han Q, Yang F, Zhou SX. Atorvastatin prevents glomerular extracellular matrix formation by interfering with the PKC signaling pathway. Mol Med Rep 2018; 17:6441-6448. [PMID: 29532876 PMCID: PMC5928626 DOI: 10.3892/mmr.2018.8724] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 01/25/2018] [Indexed: 01/21/2023] Open
Abstract
Platelet-activating factor (PAF) promotes glomerular extracellular matrix (ECM) deposition, primarily through activation of the protein kinase C (PKC) pathway. The present study was designed to investigate whether atorvastatin, which mediates a protective effect against glomerular ECM deposition and diabetic neuropathy, may interfere with the PKC‑transforming growth factor‑β1 (TGF‑β1) pathway in a model of human mesangial cells (HMCs) exposed to a high glucose (HG) and lysophosphatidylcholine (LPC) environment. HMCs were divided into three treatment groups: Control, high glucose and lysophosphatidylcholine (HG+LPC), and HG+LPC+atorvastatin. Cells were cultured for 24 h. The levels of the ECM‑associated molecules collagen IV (Col IV) and fibronectin (Fn) in the supernatant were detected using an ELISA kit. PKC‑β1, TGF‑β1 and PAF‑receptor gene expression was detected by reverse transcription‑quantitative polymerase chain reaction. PKC‑β1 and TGF‑β1 protein expression was detected by western blotting, and the subcellular localization of PKC‑β1 was assessed using immunofluorescence. The results indicated that atorvastatin may reduce the secretion of ECM components (Fn and Col IV) in HMCs in a HG and LPC environment, by inhibiting the increase in PAF secretion and the activation of the PKC‑TGF‑β1 signaling pathway.
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Affiliation(s)
- Yan-Hua Xiao
- Department of Endocrinology, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi 541001, P.R. China
| | - Xiao-Yun He
- Department of Endocrinology, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi 541001, P.R. China
- Department of Endocrinology, Xiangya Hospital, Central South University, Changsha, Hunan 410078, P.R. China
| | - Qing Han
- Department of Endocrinology, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi 541001, P.R. China
| | - Fan Yang
- Department of Endocrinology, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi 541001, P.R. China
| | - Su-Xian Zhou
- Department of Endocrinology, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi 541001, P.R. China
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Latchoumycandane C, Hanouneh M, Nagy LE, McIntyre TM. Inflammatory PAF Receptor Signaling Initiates Hedgehog Signaling and Kidney Fibrogenesis During Ethanol Consumption. PLoS One 2015; 10:e0145691. [PMID: 26720402 PMCID: PMC4697844 DOI: 10.1371/journal.pone.0145691] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 12/06/2015] [Indexed: 12/20/2022] Open
Abstract
Acute inflammation either resolves or proceeds to fibrotic repair that replaces functional tissue. Pro-fibrotic hedgehog signaling and induction of its Gli transcription factor in pericytes induces fibrosis in kidney, but molecular instructions connecting inflammation to fibrosis are opaque. We show acute kidney inflammation resulting from chronic ingestion of the common xenobiotic ethanol initiates Gli1 transcription and hedgehog synthesis in kidney pericytes, and promotes renal fibrosis. Ethanol ingestion stimulated transcription of TGF-ß, collagens I and IV, and alpha-smooth muscle actin with accumulation of these proteins. This was accompanied by deposition of extracellular fibrils. Ethanol catabolism by CYP2E1 in kidney generates local reactive oxygen species that oxidize cellular phospholipids to phospholipid products that activate the Platelet-activating Factor receptor (PTAFR) for inflammatory phospholipids. Genetically deleting this ptafr locus abolished accumulation of mRNA for TGF-ß, collagen IV, and α-smooth muscle actin. Loss of PTAFR also abolished ethanol-stimulated Sonic (Shh) and Indian hedgehog (Ihh) expression, and abolished transcription and accumulation of Gli1. Shh induced in pericytes and Ihh in tubules escaped to urine of ethanol-fed mice. Neutrophil myeloperoxidase (MPO) is required for ethanol-induced kidney inflammation, and Shh was not present in kidney or urine of mpo-/- mice. Shh also was present in urine of patients with acute kidney injury, but not in normal individuals or those with fibrotic liver cirrhosis We conclude neither endogenous PTAFR signaling nor CYP2E1-generated radicals alone are sufficient to initiate hedgehog signaling, but instead PTAFR-dependent neutrophil infiltration with myeloperoxidase activation is necessary to initiate ethanol-induced fibrosis in kidney. We also show fibrogenic mediators escape to urine, defining a new class of urinary mechanistic biomarkers of fibrogenesis for an organ not commonly biopsied.
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Affiliation(s)
- Calivarathan Latchoumycandane
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, United States of America
| | - Mohamad Hanouneh
- Department of Internal Medicine, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Laura E Nagy
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, United States of America
| | - Thomas M McIntyre
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, United States of America
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5
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Abstract
"Let's Move!" is a comprehensive initiative, launched by the First Lady, Michelle Obama, dedicates to solving problems of obesity, which is growing in child. The life behaviors do affect obesity; however, the mechanistic insight in molecular level is still not clear. In this study, by continually monitoring mouse body weight under chow and high fat western diets as well as metabolic, physical activity and food intake behaviors assessed in a CLAMS Comprehensive Lab Animal Monitoring System, we demonstrated that the platelet-activating factor receptor (PTAFR) contributes to modification of life behaviors. PTAFR does not affect metabolism of ingested dietary fat and carbohydrate in young animals; however, Ptafr ablation dramatically increased weight gain without affecting adipose tissue accumulation. Ptafr-/- mice possess new habits that increased food intake and decreased movement. Our studies suggest that regulation of PTAFR activity may be a novel strategy to control obesity in children or young adults.
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Affiliation(s)
- Wei Li
- Departments of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, USA.,Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA
| | - Thomas M McIntyre
- Departments of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, USA.,Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA
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6
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The role of platelet-activating factor in mesangial pathophysiology. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:888-96. [PMID: 25655028 DOI: 10.1016/j.ajpath.2014.11.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Revised: 11/17/2014] [Accepted: 11/25/2014] [Indexed: 01/26/2023]
Abstract
Platelet-activating factor (PAF) is a powerful proinflammatory mediator that displays an exceedingly diverse spectrum of biological effects. Importantly, PAF is shown to participate in a broad range of pathologic conditions. This review focuses on the role that PAF plays specifically in the pathophysiology of the kidney, the organ that is both a source and a target of PAF. Renal mesangial cells are responsible for glomerular PAF generation and, ultimately, are the victims of its excessive production. Mesangial pathology is widely acknowledged to reflect glomerular damage, which culminates in glomerulosclerosis and proteinuria. Therefore, modulation of mesangial cell responses would offer a pathophysiology-based therapeutic approach to prevent glomerular injury. However, the currently available therapeutic modalities do not allow for targeted intervention into these processes. A more profound understanding of the mechanisms that govern PAF metabolism and signaling in mesangial cells is important, because it could facilitate the quest for improved therapies for renal patients on the basis of PAF as a drug target.
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7
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Correa-Costa M, Andrade-Oliveira V, Braga TT, Castoldi A, Aguiar CF, Origassa CST, Rodas ACD, Hiyane MI, Malheiros DMAC, Rios FJO, Jancar S, Câmara NOS. Activation of platelet-activating factor receptor exacerbates renal inflammation and promotes fibrosis. J Transl Med 2014; 94:455-66. [PMID: 24492283 DOI: 10.1038/labinvest.2013.155] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 11/20/2013] [Accepted: 12/19/2013] [Indexed: 12/13/2022] Open
Abstract
Platelet-activating factor (PAF) is a lipid mediator with important pro-inflammatory effects, being synthesized by several cell types including kidney cells. Although there is evidence of its involvement in acute renal dysfunction, its role in progressive kidney injury is not completely known. In the present study, we investigated the role of PAF receptor (PAFR) in an experimental model of chronic renal disease. Wild-type (WT) and PAFR knockout (KO) mice underwent unilateral ureter obstruction (UUO), and at kill time, urine and kidney tissue was collected. PAFR KO animals compared with WT mice present: (a) less renal dysfunction, evaluated by urine protein/creatinine ratio; (b) less fibrosis evaluated by collagen deposition, type I collagen, Lysyl Oxidase-1 (LOX-1) and transforming growth factor β (TGF-β) gene expression, and higher expression of bone morphogenetic protein 7 (BMP-7) (3.3-fold lower TGF-β/BMP-7 ratio); (c) downregulation of extracellular matrix (ECM) and adhesion molecule-related machinery genes; and (d) lower levels of pro-inflammatory cytokines. These indicate that PAFR engagement by PAF or PAF-like molecules generated during UUO potentiates renal dysfunction and fibrosis and might promote epithelial-to-mesenchymal transition (EMT). Also, early blockade of PAFR after UUO leads to a protective effect, with less fibrosis deposition. In conclusion, PAFR signaling contributes to a pro-inflammatory environment in the model of obstructive nephropathy, favoring the fibrotic process, which lately will generate renal dysfunction and progressive organ failure.
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Affiliation(s)
- Matheus Correa-Costa
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Vinicius Andrade-Oliveira
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Tarcio T Braga
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Angela Castoldi
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Cristhiane F Aguiar
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | | | - Andrea C D Rodas
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Meire I Hiyane
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | | | - Francisco J O Rios
- 1] Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil [2] British Heart Foundation, Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - Sonia Jancar
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Niels O S Câmara
- 1] Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil [2] Nephrology Division, Federal University of São Paulo, São Paulo, Brazil
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8
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A Novel Platelet-Activating Factor Receptor Antagonist Inhibits Choroidal Neovascularization and Subretinal Fibrosis. PLoS One 2013; 8:e68173. [PMID: 23826375 PMCID: PMC3694891 DOI: 10.1371/journal.pone.0068173] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Accepted: 05/28/2013] [Indexed: 11/19/2022] Open
Abstract
Choroidal neovascularization (CNV) is a critical pathogenesis in age-related macular degeneration (AMD), the most common cause of blindness in developed countries. To date, the precise molecular and cellular mechanisms underlying CNV have not been elucidated. Platelet-activating factor (PAF) has been previously implicated in angiogenesis; however, the roles of PAF and its receptor (PAF-R) in CNV have not been addressed. The present study reveals several important findings concerning the relationship of the PAF-R signaling with CNV. PAF-R was detected in a mouse model of laser-induced CNV and was upregulated during CNV development. Experimental CNV was suppressed by administering WEB2086, a novel PAF-R antagonist. WEB2086-dependent suppression of CNV occurred via the inhibition of macrophage infiltration and the expression of proangiogenic (vascular endothelial growth factor) and proinflammatory molecules (monocyte chemotactic protein-1 and IL-6) in the retinal pigment epithelium-choroid complex. Additionally, WEB2086-induced PAF-R blockage suppresses experimentally induced subretinal fibrosis, which resembles the fibrotic subretinal scarring observed in neovascular AMD. As optimal treatment modalities for neovascular AMD would target the multiple mechanisms of AMD-associated vision loss, including neovascularization, inflammation and fibrosis, our results suggest PAF-R as an attractive molecular target in the treatment of AMD.
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9
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Angiotensin II-induced mitochondrial Nox4 is a major endogenous source of oxidative stress in kidney tubular cells. PLoS One 2012; 7:e39739. [PMID: 22808054 PMCID: PMC3392275 DOI: 10.1371/journal.pone.0039739] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 05/25/2012] [Indexed: 02/07/2023] Open
Abstract
Angiotensin II (Ang II)-induced activation of nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase leads to increased production of reactive oxygen species (ROS), an important intracellular second messenger in renal disease. Recent findings suggest that Ang II induces mitochondrial depolarization and further amplifies mitochondrial generation of ROS. We examined the hypothesis that ROS injury mediated by Ang II-induced mitochondrial Nox4 plays a pivotal role in mitochondrial dysfunction in tubular cells and is related to cell survival. In addition, we assessed whether angiotensin (1-7) peptide (Ang-(1-7)) was able to counteract Ang II-induced ROS-mediated cellular injury. Cultured NRK-52E cells were stimulated with 10−6 M Ang II for 24 h with or without Ang-(1-7) or apocynin. Ang II simulated mitochondrial Nox4 and resulted in the abrupt production of mitochondrial superoxide (O2−) and hydrogen peroxide (H2O2). Ang II also induced depolarization of the mitochondrial membrane potential, and cytosolic secretion of cytochrome C and apoptosis-inducing factor (AIF). Ang-(1-7) attenuated Ang II-induced mitochondrial Nox4 expression and apoptosis, and its effect was comparable to that of the NAD(P)H oxidase inhibitor. These findings suggest that Ang II-induced activation of mitochondrial Nox4 is an important endogenous source of ROS, and is related to cell survival. The ACE2-Ang-(1-7)-Mas receptor axis should be investigated further as a novel target of Ang II-mediated ROS injury.
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Pradère JP, Gonzalez J, Klein J, Valet P, Grès S, Salant D, Bascands JL, Saulnier-Blache JS, Schanstra JP. Lysophosphatidic acid and renal fibrosis. Biochim Biophys Acta Mol Cell Biol Lipids 2008; 1781:582-7. [PMID: 18455518 DOI: 10.1016/j.bbalip.2008.04.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Revised: 04/01/2008] [Accepted: 04/01/2008] [Indexed: 02/07/2023]
Abstract
The development of fibrosis involves a multitude of events and molecules. Until now the majority of these molecules were found to be proteins or peptides. But recent data show significant involvement of the phospholipid lysophosphatidic acid (LPA) in the development of pulmonary, liver and renal fibrosis. The latest data on the role of LPA and the G-protein-coupled LPA1 receptor in the development of renal fibrosis will be discussed. LPA1-receptor activation was found to be associated with increased vascular leakage and increased fibroblast recruitment in pulmonary fibrosis. Furthermore, in renal fibrosis LPA1-receptor activation stimulates macrophage recruitment and connective tissue growth factor expression. The observations make this receptor an interesting alternative and new therapeutic target in fibrotic diseases.
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Affiliation(s)
- Jean-Philippe Pradère
- Inserm, U858/I2MR, Department of Metabolism and Obesity, Team #3, 1 Avenue Jean Poulhès, BP 84225, 31432 Toulouse Cedex 4, France
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11
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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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Fragopoulou E, Iatrou C, Demopoulos CA. Characterization of acetyl-CoA: lyso-PAF acetyltransferase of human mesangial cells. Mediators Inflamm 2006; 2005:263-72. [PMID: 16258193 PMCID: PMC1533888 DOI: 10.1155/mi.2005.263] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Platelet activating factor (PAF) is a potent inflammatory mediator
produced by various renal cells and it is implicated in renal
pathology. The aim of this study is the characterization of
remodeling lyso-PAF acetyltransferase, which is activated
under inflammatory conditions, in human mesangial cell. Total
membranes of mesangial cells were isolated and enzymatic activity
and kinetic parameters were determined by trichloroacetic
acid precipitation method. The effect of BSA, divalent cations,
EDTA, and various chemicals on the activity of lyso-PAF
acetyltransferase was also studied. Various detergents were also
tested for the solubilization of the enzyme and only glycerol did
not affect its activity. Partial purification of solubilized
enzyme preparations of human kidney tissue and mesangial cells was
performed on anion exchange column chromatography and native-PAGE
electrophoresis and two active fractions were detected.
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Affiliation(s)
- Elizabeth Fragopoulou
- Faculty of Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis, 15771 Athens, Greece
| | - Christos Iatrou
- Centre for Nephrology, G. Papadakis General Hospital of Nikea-Pireaus, 18454 Athens, Greece
| | - Constantinos Alexandros Demopoulos
- Faculty of Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis, 15771 Athens, Greece
- * Constantinos Alexandros Demopoulos;
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Santos S, Bosch RJ, Ortega A, Largo R, Fernández-Agulló T, Gazapo R, Egido J, Esbrit P. Up-regulation of parathyroid hormone-related protein in folic acid-induced acute renal failure. Kidney Int 2001; 60:982-95. [PMID: 11532093 DOI: 10.1046/j.1523-1755.2001.060003982.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Parathyroid hormone (PTH)-related protein (PTHrP) is present in many normal tissues, including the kidney. Current evidence supports that PTHrP is involved in renal pathophysiology, although its role on the mechanisms of renal damage and/or repair is unclear. Our present study examined the changes in PTHrP and the PTH/PTHrP receptor (type 1) in folic acid-induced acute renal failure in rats. The possible role of PTHrP on the process of renal regeneration following folic acid administration, and potential interaction between angiotensin II (Ang II) and endothelin-1, and PTHrP, were examined in this animal model. METHODS PTHrP, PTH/PTHrP receptor, ACE, and preproendothelin-1 (preproET-1) mRNA levels in the rat kidney were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and/or RNase protection assay. Immunohistochemistry also was performed for PTHrP, the PTH/PTHrP receptor, and Ang II in the renal tissue of folic acid-injected rats. The role of PTHrP on tubular cell proliferation following folic acid injury was investigated in vitro in rat renal epithelial cells (NRK 52E). PTHrP secretion in the medium conditioned by these cells was measured by an immunoradiometric assay specific for the 1-36 sequence. RESULTS Using RT-PCR, PTHrP mRNA was rapidly (1 hour) and maximally increased (3-fold) in the rat kidney after folic acid, decreasing after six hours. At 72 hours, renal function was maximally decreased in these rats, associated with an increased PTHrP immunostaining in both renal tubules and glomeruli. In contrast, the PTH/PTHrP receptor mRNA (RNase protection assay) decreased shortly after folic acid administration. Moreover, PTH/PTHrP receptor immunostaining dramatically decreased in renal tubular cell membranes after folic acid. A single subcutaneous administration of PTHrP (1-36), 3 or 50 microg/kg body weight, shortly after folic acid injection increased the number of tubular cells staining for proliferating cell nuclear antigen by 30% (P < 0.05) or 50% (P < 0.01), respectively, in these rats at 24 hours, without significant changes in either renal function or calcemia. On the other hand, this peptide failed to modify the increase (2-fold over control) in ACE mRNA, associated with a prominent Ang II staining into tubular cell nuclei, in the kidney of folic acid-treated rats at this time period. The addition of 10 mmol/L folic acid to NRK 52E cells caused a twofold increase in PTHrP mRNA at six hours, without significant changes in the PTH/PTHrP receptor mRNA. The presence of two anti-PTHrP antibodies, with or without folic acid, in the cell-conditioned medium decreased (40%, P < 0.01) cell growth. CONCLUSIONS Renal PTHrP was rapidly and transiently increased in rats with folic acid-induced acute renal failure, featuring as an early response gene. In addition, changes in ACE and Ang II expression were also found in these animals. PTHrP induces a mitogenic response in folic acid-damaged renal tubular cells both in vivo and in vitro. Our results support the notion that PTHrP up-regulation participates in the regenerative process in this model of acute renal failure and is a common event associated with the mechanisms of renal injury and repair.
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Affiliation(s)
- S Santos
- Bone and Mineral Metabolism Laboratory, Fundación Jiménez Díaz, Madrid, Spain
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14
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Lloberas N, Cruzado JM, Torras J, Herrero-Fresneda I, Riera M, Merlos M, Grinyó JM. Protective effect of UR-12670 on chronic nephropathy induced by warm ischaemia in ageing uninephrectomized rats. Nephrol Dial Transplant 2001; 16:735-41. [PMID: 11274266 DOI: 10.1093/ndt/16.4.735] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND In young animals, renal ischaemia/reperfusion injury and mass reduction are associated with chronic lesions that mimic those found in chronic rejection. We have shown that the phospholipid platelet-activating factor (PAF) participates in young animals in such chronic nephropathy. Here we examine the long-term effects of the orally active PAF antagonist, UR-12670 in ageing uninephrectomized rats exposed to prolonged warm ischaemia. METHODS Fifteen- to eighteen-month-old uninephrectomized male Sprague-Dawley rats were allocated into three groups and followed for 16 weeks: UNx, rats without ischaemia; UNxISC, ischaemic kidney (60 min), and UNxISC+UR, ischaemic kidney and UR-12670 from day 0 to the 16th week. Serum creatinine and proteinuria were monitored every 4 weeks. At the end of the study, conventional histology was performed and monocyte-macrophages were identified with the specific monoclonal antibody ED-1. RESULTS The UNxISC group had severe acute renal failure with a high mortality rate, which was associated with incomplete restoration of renal function. Renal insufficiency in this group was sustained throughout the follow-up. Both UNx and UNxISC groups developed progressive proteinuria from the 12th week. Though UNxISC+UR group showed similar acute renal failure and mortality rate to the ischaemic non-treated group, serum creatinine decreased to levels similar to UNx group, which were maintained until the end of the study. Treatment of ischaemic kidneys with UR-12670 produced a slight decrease in 24-h proteinuria and a reduction in glomerulosclerosis, the mean tubulointerstitial score and number of monocyte-macrophages to values similar to UNx group. CONCLUSIONS The chronic administration of the PAF antagonist UR-12670 attenuates the long-term effects of ischaemia-reperfusion injury in uninephrectomized ageing rats. The beneficial effect of this agent suggests that PAF contributes to the progression to late renal damage in this model.
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Affiliation(s)
- N Lloberas
- Department of Nephrology and Renal Research Laboratory, Hospital of Bellvitge, L'Hospitalet, Medicine Department, University of Barcelona, CSUB, Barcelona, Spain
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15
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Abstract
An outline is given of the pathophysiology of IgA nephropathy (IgA) in order to emphasize the role of eicosanoids, angiotensin II, and reactive oxygen species. ACE inhibitors and early corticosteroid usage are prime therapies. Tonsillectomy is to be considered, certainly for individual cases. It is logical that other components of a cocktail could be (i) thromboxane antagonists, (ii) leukotriene antagonists, or (iii) PAF antagonist. In theory there should be benefit from antioxidants. Fish oils have not come up to expectation. PDGF aptamers look promising for the prevention of mesangial cell proliferation. Heparins are not used in the way that they could be. Various other agents could help reduce decline.
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16
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Torras J, Cruzado JM, Riera M, Condom E, Duque N, Herrero I, Merlos M, Espinosa L, Lloberas N, Egido J, Grinyó JM. Long-term protective effect of UR-12670 after warm renal ischemia in uninephrectomized rats. Kidney Int 1999; 56:1798-808. [PMID: 10571788 DOI: 10.1046/j.1523-1755.1999.00724.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The phospholipid platelet-activating factor (PAF) participates in the pathogenesis of renal ischemia/reperfusion injury, and in vitro, it induces synthesis of extracellular matrix proteins by mesangial and tubular epithelial cells. This study investigated the long-term effects of the potent orally active PAF antagonist UR-12670 in warm ischemic uninephrectomized rats, which was given according to different therapeutic schedules. METHODS Uninephrectomized male Sprague-Dawley rats were divided into five groups and were followed for 52 weeks: rats without ischemia (SK); ischemic kidney for 60 minutes (SIK); ischemic kidney and UR-12670 from 0 to the 7th day (UR 0-7); ischemic kidney and UR-12670 from day 0 to 52 weeks (UR 0-E); and ischemic kidney and UR-12670 from day 8 to week 52 (UR 8-E). Two more groups (ischemic and UR treated) served to evaluate the UR-12670-protective effect on ischemic acute renal failure at one week. RESULTS UR-12670 administration exerted functional and morphological protection against post-ischemic acute renal failure. The ischemic untreated (SIK) group developed progressive proteinuria from week 12. The onset of proteinuria in ischemic UR-12670-treated groups was delayed to the 24th week, and it was significantly lower than in SIK group throughout the study. Only SIK and ischemic-treated UR 0-7 rats presented with chronic renal failure, as shown by creatinine, creatinine clearance, glomerular filtration rate (GFR), and renal plasma flow (GFR 52 weeks: SK, 2525 +/- 267; SIK, 992 +/- 149; UR 0-7, 1551 +/- 385 microliter/min). Kidneys from the short-term treated group (UR 0-7) showed a reduction of glomerulosclerosis (SK, 14.4 +/- 3.7; SIK, 75.7 +/- 7.7; UR 0-7, 41. 5 +/- 8.5%) and vascular myointimal hyperplasia, but the tubulointerstitial damage (tubulointerstitial score: SK, 0.2 +/- 0. 2; SIK, 4.4 +/- 0.5; UR 0-7, 3.7 +/- 0.7) was similar to that in the ischemic untreated group. Long-term ischemic treated rats (UR 0-E, UR 8-E) did not develop chronic renal failure (GFR: UR 0-E, 2059 +/- 314; UR 8-E, 2410 +/- 208 microliter/min). In these groups, glomerulosclerosis (UR 0-E, 32.8 +/- 5.8; UR 8-E, 24.3 +/- 3.0%), tubulointerstitial damage (tubulointerstitial score: UR 0-E, 2.1 +/- 0.5; UR 8-E, 1.9 +/- 0.3) and vascular myointimal hyperplasia were significantly lower than in the ischemic untreated group. By in situ hybridization, an increase of transforming growth factor-beta1 mRNA expression in glomerular and tubular cells was observed in ischemic untreated and ischemic treated UR 0-7 rats. UR-12670 long-term treated rats showed a clear reduction of transforming growth factor-beta1 mRNA-positive glomerular cells. CONCLUSION The chronic administration of the PAF antagonist UR-12670 attenuates the long-term effects of ischemia-reperfusion injury in uninephrectomized rats. The beneficial effect of this agent, even when given beyond the initial ischemia/reperfusion injury, suggests that PAF plays a role in the mechanisms of progression to late renal damage in this model.
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Affiliation(s)
- J Torras
- Department of Nephrology, Hospital de Bellvitge, L'Hospitalet, Medicine Department, University of Barcelona, Spain
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Wardle EN. Modulatory proteins and processes in alliance with immune cells, mediators, and extracellular proteins in renal interstitial fibrosis. Ren Fail 1999; 21:121-33. [PMID: 10088173 DOI: 10.3109/08860229909066977] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A synopsis of the many aspects and factors that contribute to renal tubulo-interstitial fibrosis is presented. The role of fibrogenic cytokines and the conversion of fibroblasts to myofibroblasts are described. It is emphasized that oxygen radicals cause fibroblasts to generate collagen. The properties of those accessory modulatory proteins that affect the behavior of cells in the interstitium are considered and how matrix for ensuing fibrosis is laid down. Understanding the extracellular matrix proteins and these modulatory proteins is important because their behavior can now be modified by means of antisense oligonucleotides.
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