1
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Andrews M, Yoshida T, Henderson CM, Pflaum H, McGregor A, Lieberman JA, de Boer IH, Vaisar T, Himmelfarb J, Kestenbaum B, Chung JY, Hewitt SM, Santo BA, Ginley B, Sarder P, Rosenberg AZ, Murakami T, Kopp JB, Kuklenyik Z, Hoofnagle AN. Variant APOL1 protein in plasma associates with larger particles in humans and mouse models of kidney injury. PLoS One 2022; 17:e0276649. [PMID: 36279295 PMCID: PMC9591058 DOI: 10.1371/journal.pone.0276649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 10/11/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Genetic variants in apolipoprotein L1 (APOL1), a protein that protects humans from infection with African trypanosomes, explain a substantial proportion of the excess risk of chronic kidney disease affecting individuals with sub-Saharan ancestry. The mechanisms by which risk variants damage kidney cells remain incompletely understood. In preclinical models, APOL1 expressed in podocytes can lead to significant kidney injury. In humans, studies in kidney transplant suggest that the effects of APOL1 variants are predominantly driven by donor genotype. Less attention has been paid to a possible role for circulating APOL1 in kidney injury. METHODS Using liquid chromatography-tandem mass spectrometry, the concentrations of APOL1 were measured in plasma and urine from participants in the Seattle Kidney Study. Asymmetric flow field-flow fractionation was used to evaluate the size of APOL1-containing lipoprotein particles in plasma. Transgenic mice that express wild-type or risk variant APOL1 from an albumin promoter were treated to cause kidney injury and evaluated for renal disease and pathology. RESULTS In human participants, urine concentrations of APOL1 were correlated with plasma concentrations and reduced kidney function. Risk variant APOL1 was enriched in larger particles. In mice, circulating risk variant APOL1-G1 promoted kidney damage and reduced podocyte density without renal expression of APOL1. CONCLUSIONS These results suggest that plasma APOL1 is dynamic and contributes to the progression of kidney disease in humans, which may have implications for treatment of APOL1-associated kidney disease and for kidney transplantation.
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Affiliation(s)
- Michael Andrews
- Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Teruhiko Yoshida
- Kidney Disease Section, Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Clark M. Henderson
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Hannah Pflaum
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Ayako McGregor
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Joshua A. Lieberman
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
| | - Ian H. de Boer
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Kidney Research Institute, University of Washington, Seattle, Washington, United States of America
| | - Tomas Vaisar
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Jonathan Himmelfarb
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Kidney Research Institute, University of Washington, Seattle, Washington, United States of America
| | - Bryan Kestenbaum
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Kidney Research Institute, University of Washington, Seattle, Washington, United States of America
| | - Joon-Yong Chung
- Center for Cancer Research, NCI, NIH, Bethesda, Maryland, United States of America
| | - Stephen M. Hewitt
- Center for Cancer Research, NCI, NIH, Bethesda, Maryland, United States of America
| | - Briana A. Santo
- Department of Pathology and Anatomical Sciences, Jacobs School of Medicine & Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Brandon Ginley
- Department of Pathology and Anatomical Sciences, Jacobs School of Medicine & Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Pinaki Sarder
- Department of Pathology and Anatomical Sciences, Jacobs School of Medicine & Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Avi Z. Rosenberg
- Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, Maryland, United States of America
| | - Taichi Murakami
- Kidney Disease Section, Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Department of Nephrology, Ehime Prefectural Central Hospital, Ehime, Japan
| | - Jeffrey B. Kopp
- Kidney Disease Section, Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Zsuzsanna Kuklenyik
- Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Andrew N. Hoofnagle
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, United States of America
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Kidney Research Institute, University of Washington, Seattle, Washington, United States of America
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2
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Cornelissen A, Fuller DT, Fernandez R, Zhao X, Kutys R, Binns-Roemer E, Delsante M, Sakamoto A, Paek KH, Sato Y, Kawakami R, Mori M, Kawai K, Yoshida T, Latt KZ, Miller CL, de Vries PS, Kolodgie FD, Virmani R, Shin MK, Hoek M, Heymann J, Kopp JB, Rosenberg AZ, Davis HR, Guo L, Finn AV. APOL1 Genetic Variants Are Associated With Increased Risk of Coronary Atherosclerotic Plaque Rupture in the Black Population. Arterioscler Thromb Vasc Biol 2021; 41:2201-2214. [PMID: 34039022 DOI: 10.1161/atvbaha.120.315788] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Anne Cornelissen
- CVPath Institute, Gaithersburg, MD (A.C., D.T.F., R.F., X.Z., R. Kutys, A.S, K.H.P., Y.S., R. Kawakami, M.M., K.K., F.D.K., R.V., H.R.D., L.G., A.V.F.).,Department of Cardiology, University Hospital RWTH Aachen, Germany (A.C.)
| | - Daniela T Fuller
- CVPath Institute, Gaithersburg, MD (A.C., D.T.F., R.F., X.Z., R. Kutys, A.S, K.H.P., Y.S., R. Kawakami, M.M., K.K., F.D.K., R.V., H.R.D., L.G., A.V.F.)
| | - Raquel Fernandez
- CVPath Institute, Gaithersburg, MD (A.C., D.T.F., R.F., X.Z., R. Kutys, A.S, K.H.P., Y.S., R. Kawakami, M.M., K.K., F.D.K., R.V., H.R.D., L.G., A.V.F.)
| | - Xiaoqing Zhao
- CVPath Institute, Gaithersburg, MD (A.C., D.T.F., R.F., X.Z., R. Kutys, A.S, K.H.P., Y.S., R. Kawakami, M.M., K.K., F.D.K., R.V., H.R.D., L.G., A.V.F.)
| | - Robert Kutys
- CVPath Institute, Gaithersburg, MD (A.C., D.T.F., R.F., X.Z., R. Kutys, A.S, K.H.P., Y.S., R. Kawakami, M.M., K.K., F.D.K., R.V., H.R.D., L.G., A.V.F.)
| | - Elizabeth Binns-Roemer
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD (E.B.-R.)
| | - Marco Delsante
- Kidney Disease Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD (M.D., T.Y., K.Z.L., J.H., J.B.K., A.Z.R.).,Dipartimento di Medicina e Chirurgia Università di Parma, UO Nefrologia, Azienda Ospedaliera-Universitaria, Italy (M.D.)
| | - Atsushi Sakamoto
- CVPath Institute, Gaithersburg, MD (A.C., D.T.F., R.F., X.Z., R. Kutys, A.S, K.H.P., Y.S., R. Kawakami, M.M., K.K., F.D.K., R.V., H.R.D., L.G., A.V.F.)
| | - Ka Hyun Paek
- CVPath Institute, Gaithersburg, MD (A.C., D.T.F., R.F., X.Z., R. Kutys, A.S, K.H.P., Y.S., R. Kawakami, M.M., K.K., F.D.K., R.V., H.R.D., L.G., A.V.F.)
| | | | - Rika Kawakami
- CVPath Institute, Gaithersburg, MD (A.C., D.T.F., R.F., X.Z., R. Kutys, A.S, K.H.P., Y.S., R. Kawakami, M.M., K.K., F.D.K., R.V., H.R.D., L.G., A.V.F.)
| | - Masayuki Mori
- CVPath Institute, Gaithersburg, MD (A.C., D.T.F., R.F., X.Z., R. Kutys, A.S, K.H.P., Y.S., R. Kawakami, M.M., K.K., F.D.K., R.V., H.R.D., L.G., A.V.F.)
| | - Kenji Kawai
- CVPath Institute, Gaithersburg, MD (A.C., D.T.F., R.F., X.Z., R. Kutys, A.S, K.H.P., Y.S., R. Kawakami, M.M., K.K., F.D.K., R.V., H.R.D., L.G., A.V.F.)
| | - Teruhiko Yoshida
- Kidney Disease Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD (M.D., T.Y., K.Z.L., J.H., J.B.K., A.Z.R.)
| | - Khun Zaw Latt
- Kidney Disease Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD (M.D., T.Y., K.Z.L., J.H., J.B.K., A.Z.R.)
| | - Clint L Miller
- Department of Public Health Sciences, Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville (C.L.M.)
| | - Paul S de Vries
- Human Genetics Center, Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston (P.S.d.V.)
| | - Frank D Kolodgie
- CVPath Institute, Gaithersburg, MD (A.C., D.T.F., R.F., X.Z., R. Kutys, A.S, K.H.P., Y.S., R. Kawakami, M.M., K.K., F.D.K., R.V., H.R.D., L.G., A.V.F.)
| | | | | | | | - Jurgen Heymann
- Kidney Disease Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD (M.D., T.Y., K.Z.L., J.H., J.B.K., A.Z.R.)
| | - Jeffrey B Kopp
- Kidney Disease Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD (M.D., T.Y., K.Z.L., J.H., J.B.K., A.Z.R.)
| | - Avi Z Rosenberg
- Kidney Disease Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD (M.D., T.Y., K.Z.L., J.H., J.B.K., A.Z.R.).,Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD (A.Z.R.)
| | - Harry R Davis
- CVPath Institute, Gaithersburg, MD (A.C., D.T.F., R.F., X.Z., R. Kutys, A.S, K.H.P., Y.S., R. Kawakami, M.M., K.K., F.D.K., R.V., H.R.D., L.G., A.V.F.)
| | - Liang Guo
- CVPath Institute, Gaithersburg, MD (A.C., D.T.F., R.F., X.Z., R. Kutys, A.S, K.H.P., Y.S., R. Kawakami, M.M., K.K., F.D.K., R.V., H.R.D., L.G., A.V.F.)
| | - Aloke V Finn
- CVPath Institute, Gaithersburg, MD (A.C., D.T.F., R.F., X.Z., R. Kutys, A.S, K.H.P., Y.S., R. Kawakami, M.M., K.K., F.D.K., R.V., H.R.D., L.G., A.V.F.).,School of Medicine, University of Maryland School of Medicine, Baltimore (A.V.F.)
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3
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Zakharova NB, Pastyshkova LK, Goncharova AG, Orlova KD, Kashirina DN, Goncharov IN, Brzhozovsky AG, Ponomarev SA, Morozova OL, Larina IM. [Chromato-mass spectrometric analysis of urine proteins associated with the functions of Toll-receptors in a healthy person under conditions of 17-day isolation.]. Klin Lab Diagn 2020; 65:469-473. [PMID: 32762187 DOI: 10.18821/0869-2084-2020-65-8-469-473] [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] [Indexed: 06/11/2023]
Abstract
Under controlled conditions of 17-day isolation (Sirius-17 experiment), the protein composition of urine was studied in 6 healthy test volunteers-3 women and 3 men. Collection of samples in the form of a second freely separated morning urine fraction was carried out in the background (seven days before the experiment), as well as 1 day after the end of exposure. Chromatographic-mass-spectrometric semi-quantitative analysis of the protein composition of samples was performed on a system consisting of an Agilent 1100 chromatograph and an LTQ-FT Ultra hybrid mass spectrometer using bioinformatics resources UniProtKB, GeneOntology. An asymptomatic change in the immune defense system of kidney tissue after isolation in a closed hermetic object is associated with a change in the content of 7 proteins that provide functional activity of the TLR tubules of the kidneys - FcRIII, MUC1, Galectin-3, Ficolin-2, APOA1, FLNA, FCGR3A and Clusterin. These proteins are found to be useful biomarkers in the study of physiology and kidney diseases. They can be attributed to candidates for protein markers of the initial stages of impaired recognition by the epithelium of renal tubules of bacteria with known pathogenic potential.
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Affiliation(s)
- N B Zakharova
- V. Razumovsky State medical University of Saratov Ministry of health of Russia, 410012, Saratov, Russia
| | | | - A G Goncharova
- Institute of biomedical problems RAN 123007, Moscow, Russia
| | - K D Orlova
- Institute of biomedical problems RAN 123007, Moscow, Russia
| | - D N Kashirina
- Institute of biomedical problems RAN 123007, Moscow, Russia
| | - I N Goncharov
- Institute of biomedical problems RAN 123007, Moscow, Russia
| | | | - S A Ponomarev
- Institute of biomedical problems RAN 123007, Moscow, Russia
| | - O L Morozova
- Department of Pathophysiology, Sechenov First Moscow State Medical University (Sechenov University), 119991, Moscow, Russia
| | - I M Larina
- Institute of biomedical problems RAN 123007, Moscow, Russia
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4
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Jacobs-Cachá C, Puig-Gay N, Helm D, Rettel M, Sellarès J, Meseguer A, Savitski MM, Moreso FJ, Soler MJ, Seron D, Lopez-Hellin J. A misprocessed form of Apolipoprotein A-I is specifically associated with recurrent Focal Segmental Glomerulosclerosis. Sci Rep 2020; 10:1159. [PMID: 31980684 PMCID: PMC6981185 DOI: 10.1038/s41598-020-58197-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 01/10/2020] [Indexed: 12/29/2022] Open
Abstract
Apolipoprotein A-Ib (ApoA-Ib) is a high molecular weight form of Apolipoprotein A-I (ApoA-I) found specifically in the urine of kidney-transplanted patients with recurrent idiopathic focal segmental glomerulosclerosis (FSGS). To determine the nature of the modification present in ApoA-Ib, we sequenced the whole APOA1 gene in ApoA-Ib positive and negative patients, and we also studied the protein primary structure using mass spectrometry. No genetic variations in the APOA1 gene were found in the ApoA-Ib positive patients that could explain the increase in its molecular mass. The mass spectrometry analysis revealed three extra amino acids at the N-Terminal end of ApoA-Ib that were not present in the standard plasmatic form of ApoA-I. These amino acids corresponded to half of the propeptide sequence of the immature form of ApoA-I (proApoA-I) indicating that ApoA-Ib is a misprocessed form of proApoA-I. The description of ApoA-Ib could be relevant not only because it can allow the automated analysis of this biomarker in the clinical practice but also because it has the potential to shed light into the molecular mechanisms that cause idiopathic FSGS, which is currently unknown.
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Affiliation(s)
- Conxita Jacobs-Cachá
- Nephrology Research Group, Hospital Vall d'Hebron Institut de Recerca (VHIR), Barcelona, Spain. .,Nephrology Department, Hospital Vall d'Hebrón, Barcelona, Spain.
| | - Natàlia Puig-Gay
- Renal Physiopathology Group-CIBBIM. Hospital Vall d'Hebron Institut de Recerca (VHIR), Barcelona, Spain
| | - Dominic Helm
- Proteomics Core Facility, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Mandy Rettel
- Proteomics Core Facility, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Joana Sellarès
- Nephrology Research Group, Hospital Vall d'Hebron Institut de Recerca (VHIR), Barcelona, Spain.,Nephrology Department, Hospital Vall d'Hebrón, Barcelona, Spain
| | - Anna Meseguer
- Renal Physiopathology Group-CIBBIM. Hospital Vall d'Hebron Institut de Recerca (VHIR), Barcelona, Spain
| | - Mikhail M Savitski
- Proteomics Core Facility, European Molecular Biology Laboratory, Heidelberg, Germany.,Genome Biology, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Francesc J Moreso
- Nephrology Research Group, Hospital Vall d'Hebron Institut de Recerca (VHIR), Barcelona, Spain.,Nephrology Department, Hospital Vall d'Hebrón, Barcelona, Spain
| | - Maria José Soler
- Nephrology Research Group, Hospital Vall d'Hebron Institut de Recerca (VHIR), Barcelona, Spain.,Nephrology Department, Hospital Vall d'Hebrón, Barcelona, Spain
| | - Daniel Seron
- Nephrology Research Group, Hospital Vall d'Hebron Institut de Recerca (VHIR), Barcelona, Spain.,Nephrology Department, Hospital Vall d'Hebrón, Barcelona, Spain
| | - Joan Lopez-Hellin
- Renal Physiopathology Group-CIBBIM. Hospital Vall d'Hebron Institut de Recerca (VHIR), Barcelona, Spain. .,Biochemistry Department, Hospital Vall d'Hebrón, Barcelona, Spain.
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5
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The Role and Function of HDL in Patients with Chronic Kidney Disease and the Risk of Cardiovascular Disease. Int J Mol Sci 2020; 21:ijms21020601. [PMID: 31963445 PMCID: PMC7014265 DOI: 10.3390/ijms21020601] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 02/06/2023] Open
Abstract
Chronic kidney disease (CKD) is a worldwide health problem with steadily increasing occurrence. Significantly elevated cardiovascular morbidity and mortality have been observed in CKD. Cardiovascular diseases are the most important and frequent cause of death of CKD patients globally. The presence of CKD is related to disturbances in lipoprotein metabolism whose consequences are dyslipidemia and the accumulation of atherogenic particles. CKD not only fuels the reduction of high-density lipoprotein (HDL) cholesterol concentration, but also it modifies the composition of this lipoprotein. The key role of HDL is the participation in reverse cholesterol transport from peripheral tissues to the liver. Moreover, HDL prevents the oxidation of low-density lipoprotein (LDL) cholesterol by reactive oxygen species (ROS) and protects against the adverse effects of oxidized LDL (ox-LDL) on the endothelium. Numerous studies have demonstrated the ability of HDL to promote the production of nitric oxide (NO) by endothelial cells (ECs) and to exert antiapoptotic and anti-inflammatory effects. Increasing evidence suggests that in patients with chronic inflammatory disorders, HDLs may lose important antiatherosclerotic properties and become dysfunctional. So far, no therapeutic strategy to raise HDL, or alter the ratio of HDL subfractions, has been successful in slowing the progression of CKD or reducing cardiovascular disease in patients either with or without CKD.
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6
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Abstract
BACKGROUND An improved understanding of the pathogenesis in apolipoprotein L1 (APOL1) gene-associated chronic kidney disease (CKD) arose from observations in kidney transplantation. APOL1 genotyping could soon improve the safety of living kidney donation in individuals with recent African ancestry and alter the allocation of deceased donor kidneys. METHODS This article reviews the potential mechanisms that underlie development of APOL1-associated nephropathy. Roles for circulating APOL1 protein versus intrinsic renal expression of APOL1 are discussed, as well as the requirement for modifying genetic and/or environmental factors. RESULTS Abundant evidence supports local kidney production of APOL1 renal-risk variant protein in the development of nephropathy; this is true in both native kidney disease and after renal transplantation. Only a minority of kidneys from individuals with APOL1 high-risk genotypes will develop CKD or manifest shorter renal allograft survival after transplantation. Therefore, modifying factors that explain why only a subset of kidneys develops nephropathy remain critical to identify. It appears likely that environmental exposures, as opposed to major APOL1-second gene interactions, will prove to be stronger modifiers of the risk for nephropathy. CONCLUSIONS The evolving understanding of the pathogenesis in APOL1-associated nephropathy will identify biomarkers predicting nephropathy in individuals at high genetic risk and lead to novel therapies to prevent or slow native CKD progression and prolong survival of transplanted kidneys. In the interim, the National Institutes of Health-sponsored "APOL1 Long-term Kidney Transplantation Outcomes" Network will determine whether APOL1 genotyping in individuals with recent African ancestry improves outcomes and safety in kidney transplantation.
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7
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Ryu JH, Ge M, Merscher S, Rosenberg AZ, Desante M, Roshanravan H, Okamoto K, Shin MK, Hoek M, Fornoni A, Kopp JB. APOL1 renal risk variants promote cholesterol accumulation in tissues and cultured macrophages from APOL1 transgenic mice. PLoS One 2019; 14:e0211559. [PMID: 30998685 PMCID: PMC6472726 DOI: 10.1371/journal.pone.0211559] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 01/16/2019] [Indexed: 02/06/2023] Open
Abstract
Apolipoprotein L1 (APOL1) genetic variants G1 and G2, compared to the common allele G0, are major risk factors for non-diabetic kidney disease in African descent populations. APOL1 is a minor protein component of HDL, as well as being expressed in podocytes and vascular cells. Reverse cholesterol transport involves the transport of cholesterol to HDL by cellular ATP-binding cassette; ABCA1 and ABCG1 with subsequent delivery from peripheral tissues to the liver. With impaired reverse cholesterol transport, lipid accumulation occurs and macrophages morphologically transform into foam cells, releasing inflammatory factors. We asked whether the APOL1 risk variants alter peripheral cholesterol metabolism and specifically affect macrophage cholesterol efflux. Tissues and bone marrow (BM)-derived monocytes were isolated from wild-type mice (WT) and from BAC/APOL1 transgenic (APOL1-G0, APOL1-G1, and APOL1-G2) mice, which carry a bacterial artificial chromosome that contains the human APOL1 genomic region. Monocytes were differentiated into macrophages using M-CSF, and then polarized into M1 and M2 macrophages. Cholesterol content, cholesterol efflux, and ABCA1 and ABCG1 mRNA expression were measured. Kidney, spleen, and bone marrow-derived macrophages from APOL1-G1 and -G2 mice showed increased cholesterol accumulation and decreased ABCA1 and ABCG1 mRNA levels. BM-derived macrophages from APOL1-G1 and -G2 mice showed significantly reduced cholesterol efflux compared to WT or APOL1-G0 macrophages. Taken together, the evidence suggests that APOL1-G1 and -G2 risk variants impaired reverse cholesterol transport through decreased expression of cholesterol efflux transporters suggesting a possible mechanism to promote macrophage foam cell formation, driving inflammation in the glomerulus and renal interstitium.
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Affiliation(s)
- Jung-Hwa Ryu
- Kidney Disease Section, NIDDK, NIH, Bethesda, Maryland, United States of America
| | - Mengyuan Ge
- Katz Family Division of Nephrology and Hypertension and Peggy and Harold Katz Drug Discovery Center, University of Miami School of Medicine, Miami, Florida, United States of America
| | - Sandra Merscher
- Katz Family Division of Nephrology and Hypertension and Peggy and Harold Katz Drug Discovery Center, University of Miami School of Medicine, Miami, Florida, United States of America
| | - Avi Z. Rosenberg
- Dvision of Pathology, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Marco Desante
- Dvision of Pathology, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Hila Roshanravan
- Kidney Disease Section, NIDDK, NIH, Bethesda, Maryland, United States of America
| | - Koji Okamoto
- Kidney Disease Section, NIDDK, NIH, Bethesda, Maryland, United States of America
| | - Myung K. Shin
- Merck & Company, Inc., Kennilworth, New Jersey, United States of America
| | - Maarten Hoek
- Merck & Company, Inc., Kennilworth, New Jersey, United States of America
| | - Alessia Fornoni
- Katz Family Division of Nephrology and Hypertension and Peggy and Harold Katz Drug Discovery Center, University of Miami School of Medicine, Miami, Florida, United States of America
- * E-mail: (JK); (AF)
| | - Jeffrey B. Kopp
- Kidney Disease Section, NIDDK, NIH, Bethesda, Maryland, United States of America
- * E-mail: (JK); (AF)
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8
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Estrella MM, Parekh RS. The Expanding Role of APOL1 Risk in Chronic Kidney Disease and Cardiovascular Disease. Semin Nephrol 2018; 37:520-529. [PMID: 29110759 DOI: 10.1016/j.semnephrol.2017.07.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Variants of the APOL1 gene, found primarily in individuals of African descent, are associated with various forms of kidney disease and kidney disease progression. Recent studies evaluating the association of APOL1 with cardiovascular disease have yielded conflicting results, and the potential role in cardiovascular disease remains unclear. In this review, we summarize the observational studies linking the APOL1 risk variants with chronic kidney and cardiovascular disease among persons of African descent.
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Affiliation(s)
- Michelle M Estrella
- Kidney Health Research Collaborative, Department of Medicine, University of California San Francisco, San Francisco, CA; Department of Medicine, San Francisco VA Medical Center, San Francisco, CA
| | - Rulan S Parekh
- Division of Nephrology, Departments of Pediatrics and Medicine, The Hospital for Sick Children, SickKids Research Institute, University Health Network, University of Toronto, Toronto, Ontario, Canada.
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9
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Rubinow KB, Henderson CM, Robinson-Cohen C, Himmelfarb J, de Boer IH, Vaisar T, Kestenbaum B, Hoofnagle AN. Kidney function is associated with an altered protein composition of high-density lipoprotein. Kidney Int 2017; 92:1526-1535. [PMID: 28754556 DOI: 10.1016/j.kint.2017.05.020] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 05/16/2017] [Accepted: 05/18/2017] [Indexed: 12/28/2022]
Abstract
Patients with chronic kidney disease (CKD) exhibit a myriad of metabolic derangements, including dyslipidemia characterized by low plasma concentrations of high-density lipoprotein (HDL)-associated cholesterol. However, the effects of kidney disease on HDL composition have not been comprehensively determined. Here we used a targeted mass spectrometric approach to quantify 38 proteins contained in the HDL particles within a CKD cohort of 509 participants with a broad range of estimated glomerular filtration rates (eGFRs) (CKD stages I-V, and a mean eGFR of 45.5 mL/min/1.73m2). After adjusting for multiple testing, demographics, comorbidities, medications, and other characteristics, eGFR was significantly associated with differences in four HDL proteins. Compared to participants with an eGFR of 60 mL/min/1.73m2 or more, those with an eGFR under 15 mL/min/1.73m2 exhibited 1.89-fold higher retinol-binding protein 4 (95% confidence interval 1.34-2.67), 1.52-fold higher apolipoprotein C-III (1.25-1.84), 0.70-fold lower apolipoprotein L1 (0.55-0.92), and 0.64-fold lower vitronectin (0.48-0.85). Although the HDL apolipoprotein L1 was slightly lower among African Americans than among Caucasian individuals, the relationship to eGFR did not differ by race. After adjustment, no HDL-associated proteins associated with albuminuria. Thus, modest changes in the HDL proteome provide preliminary evidence for an association between HDL proteins and declining kidney function, but this needs to be replicated. Future analyses will determine if HDL proteomics is indeed a clinical predictor of declining kidney function or cardiovascular outcomes.
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Affiliation(s)
- Katya B Rubinow
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Clark M Henderson
- Department of Laboratory Medicine, University of Washington, Seattle, Washington, USA
| | - Cassianne Robinson-Cohen
- Department of Medicine, University of Washington, Seattle, Washington, USA; Kidney Research Institute, University of Washington, Seattle, Washington, USA
| | - Jonathan Himmelfarb
- Department of Medicine, University of Washington, Seattle, Washington, USA; Kidney Research Institute, University of Washington, Seattle, Washington, USA
| | - Ian H de Boer
- Department of Medicine, University of Washington, Seattle, Washington, USA; Kidney Research Institute, University of Washington, Seattle, Washington, USA
| | - Tomas Vaisar
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Bryan Kestenbaum
- Department of Medicine, University of Washington, Seattle, Washington, USA; Kidney Research Institute, University of Washington, Seattle, Washington, USA
| | - Andrew N Hoofnagle
- Department of Medicine, University of Washington, Seattle, Washington, USA; Department of Laboratory Medicine, University of Washington, Seattle, Washington, USA; Kidney Research Institute, University of Washington, Seattle, Washington, USA.
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10
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Robinson TW, Freedman BI. The Apolipoprotein L1 Gene and Cardiovascular Disease. Methodist Debakey Cardiovasc J 2017; 12:2-5. [PMID: 28298955 DOI: 10.14797/mdcj-12-4s1-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Relative to those with European ancestry, African Americans have an excess incidence of nondiabetic chronic kidney disease predominantly due to two coding renal-risk variants in the apolipoprotein L1 gene (APOL1). This APOL1-kidney disease association is independent of systemic hypertension or blood pressure. Recent reports describe extra-renal effects of the APOL1 G1 and G2 renal-risk variants on cardiovascular disease (CVD), subclinical atherosclerosis, lipoprotein particle concentrations, and survival. However, results have been less consistent than those seen in kidney disease, and the observed APOL1 associations with CVD vary from risk to protective. This manuscript reviews the relationships between APOL1 renal-risk variants and CVD, with an emphasis on study-specific factors that may have contributed to disparate observations. It is possible that APOL1 renal-risk variants impact the systemic vasculature, not only the kidneys. As novel therapies for APOL1-associated nephropathy are developed, APOL1 variant protein effects on large blood vessels and risk of CVD will need to be considered.
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Affiliation(s)
- Todd W Robinson
- Wake Forest School of Medicine, Winston-Salem, North Carolina
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11
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Abstract
PURPOSE OF REVIEW There are evolving epidemiological and biological data to support an association between the gene encoding apolipoprotein-L1 (APOL1) and progressive chronic kidney disease (CKD) among African-Americans. RECENT FINDINGS Individuals with two APOL1 risk alleles are at greater risk of incident albuminuria, CKD, and progression to end-stage renal disease despite optimal blood pressure management and use of angiotensin-converting enzyme inhibitors. These variants also appear to influence outcomes in donor and recipients in kidney transplantation. Recent studies have also variably shown a potential role of APOL1 variants in cardiovascular disease. A number of studies have addressed genetic and environmental factors such as HIV but most do not modify the course of APOL1-related kidney disease. Although the exact mechanism remains unclear, functional studies have demonstrated the effect of APOL1 and related protein on innate immunity and cytotoxicity. SUMMARY APOL1 is an important genetic risk factor for kidney disease among African-Americans. With approximately one in 10 African-Americans at risk, further studies are warranted to identify underlying biological mechanisms and other potential modifiers leading to CKD. Moreover, studies that clarify the association of APOL1 variants with cardiovascular disease, independent of CKD, are also needed.
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Reiner AP, Susztak K. APOL1 Variants: From Parasites to Kidney Function to Cardiovascular Disease. Arterioscler Thromb Vasc Biol 2016; 36:219-20. [PMID: 26819463 DOI: 10.1161/atvbaha.115.306794] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Alex P Reiner
- From the Fred Hutchinson Cancer Research Center, WHI Clinical Coordinating Center/Public Health Sciences (A.P.R.), and Renal Electrolyte and Hypertension Division, Department of Medicine, Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia (K.S.).
| | - Katalin Susztak
- From the Fred Hutchinson Cancer Research Center, WHI Clinical Coordinating Center/Public Health Sciences (A.P.R.), and Renal Electrolyte and Hypertension Division, Department of Medicine, Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia (K.S.).
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13
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Dummer PD, Limou S, Rosenberg AZ, Heymann J, Nelson G, Winkler CA, Kopp JB. APOL1 Kidney Disease Risk Variants: An Evolving Landscape. Semin Nephrol 2016. [PMID: 26215860 DOI: 10.1016/j.semnephrol.2015.04.008] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Apolipoprotein L1 (APOL1) genetic variants account for much of the excess risk of chronic and end-stage kidney disease, which results in a significant global health disparity for persons of African ancestry. We estimate the lifetime risk of kidney disease in APOL1 dual-risk allele individuals to be at least 15%. Experimental evidence suggests a direct role of APOL1 in pore formation, cellular injury, and programmed cell death in renal injury. The APOL1 BH3 motif, often associated with cell death, is unlikely to play a role in APOL1-induced cytotoxicity because it is not conserved within the APOL family and is dispensable for cell death in vitro. We discuss two models for APOL1 trypanolytic activity: one involving lysosome permeabilization and another involving colloid-osmotic swelling of the cell body, as well as their relevance to human pathophysiology. Experimental evidence from human cell culture models suggests that both mechanisms may be operative. A systems biology approach whereby APOL1-associated perturbations in gene and protein expression in affected individuals are correlated with molecular pathways may be productive to elucidate APOL1 function in vivo.
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Affiliation(s)
- Patrick D Dummer
- Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - Sophie Limou
- Molecular Epidemiology Genetics Section, Center for Cancer Research, National Cancer Institute, Frederick MD
| | - Avi Z Rosenberg
- Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD; Department of Pathology Johns Hopkins University, Baltimore, MD
| | - Jurgen Heymann
- Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - George Nelson
- Molecular Epidemiology Genetics Section, Center for Cancer Research, National Cancer Institute, Frederick MD
| | - Cheryl A Winkler
- Molecular Epidemiology Genetics Section, Center for Cancer Research, National Cancer Institute, Frederick MD
| | - Jeffrey B Kopp
- Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD.
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Gutiérrez OM, Judd SE, Irvin MR, Zhi D, Limdi N, Palmer ND, Rich SS, Sale MM, Freedman BI. APOL1 nephropathy risk variants are associated with altered high-density lipoprotein profiles in African Americans. Nephrol Dial Transplant 2015; 31:602-8. [PMID: 26152403 DOI: 10.1093/ndt/gfv229] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 04/22/2015] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Two independent coding variants in the apolipoprotein L1 gene (APOL1), G1 and G2, strongly associate with nephropathy in African Americans; associations with cardiovascular disease are more controversial. Although APOL1 binds plasma high-density lipoproteins (HDLs), data on APOL1 risk variant associations with HDL subfractions are sparse. METHODS Two APOL1 G1 single nucleotide polymorphisms and the G2 insertion/deletion polymorphism were genotyped in 2010 Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study participants with nuclear magnetic resonance spectroscopy-based lipoprotein subfraction measurements. Linear regression was used to model associations between numbers of APOL1 G1/G2 risk variants and HDL subfractions, adjusting for demographic, clinical and ancestral covariates. RESULTS Female sex and higher percentage of African ancestry were positively associated with the number of APOL1 G1/G2 risk alleles. In the unadjusted analysis, mean (standard error) small HDL concentrations (μmol/L) for participants with zero, one and two G1/G2 risk alleles were 19.0 (0.2), 19.7 (0.2) and 19.9 (0.4), respectively (P = 0.02). Adjustment for age, sex, diabetes and African ancestry did not change the results but strengthened the statistical significance (P = 0.004). No significant differences in large or medium HDL, very low-density lipoprotein or low-density lipoprotein particle concentrations were observed by APOL1 genotype. CONCLUSIONS Greater numbers of APOL1 G1/G2 risk alleles were associated with higher small HDL particle concentrations in African Americans. These results may suggest novel areas of investigation to uncover reasons for the association between APOL1 risk variants with adverse outcomes in African Americans.
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Affiliation(s)
- Orlando M Gutiérrez
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA Department of Epidemiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Suzanne E Judd
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Marguerite R Irvin
- Department of Epidemiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Degui Zhi
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Nita Limdi
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Nicholette D Palmer
- Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, NC, USA Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Stephen S Rich
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA Department of Public Health Sciences, University of Virginia, Charlottesville, VA, USA Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | - Michèle M Sale
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA Department of Public Health Sciences, University of Virginia, Charlottesville, VA, USA Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | - Barry I Freedman
- Department of Internal Medicine-Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, NC, USA
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15
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Matsha TE, Kengne AP, Masconi KL, Yako YY, Erasmus RT. APOL1 genetic variants, chronic kidney diseases and hypertension in mixed ancestry South Africans. BMC Genet 2015; 16:69. [PMID: 26112018 PMCID: PMC4482162 DOI: 10.1186/s12863-015-0228-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 06/10/2015] [Indexed: 01/07/2023] Open
Abstract
Background The frequencies of apolipoprotein L1 (APOL1) variants and their associations with chronic kidney disease (CKD) vary substantially in populations from Africa. Moreover, available studies have used very small sample sizes to provide reliable estimates of the frequencies of these variants in the general population. We determined the frequency of the two APOL1 risk alleles (G1 and G2) and investigated their association with renal traits in a relatively large sample of mixed-ancestry South Africans. APOL1 risk variants (G1: rs60910145 and rs73885319; G2: rs71785313) were genotyped in 859 African mixed ancestry individuals using allele-specific TaqMan technology. Glomerular filtration rate (eGFR) was estimated using the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. Results The frequencies of rs73885319, rs60910145 and rs71785313 risk alleles were respectively, 3.6 %, 3.4 %, and 5.8 %, resulting in a 1.01 % frequency of the APOL1 two-risk allele (G1:G1 or G1:G2 or G2:G2). The presence of the two-risk allele increased serum creatinine with a corresponding reduction in eGFR (either MDRD or CKD-EPI based). In dominant and log-additive genetic models, significant associations were found between rs71785313 and systolic blood pressure (both p ≤ 0.025), with a significant statistical interaction by diabetes status, p = 0.022, reflecting a negative non-significant effect in nondiabetics and a positive effect in diabetics. Conclusions Although the APOL1 variants are not common in the mixed ancestry population of South Africa, the study does provide an indication that APOL1 variants may play a role in conferring an increased risk for renal and cardiovascular risk in this population.
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Affiliation(s)
- Tandi E Matsha
- Department of Biomedical Sciences, Faculty of Health and Wellness Science, Cape Peninsula University of Technology, PO Box 1906, Bellville, Cape Town, 7530, South Africa.
| | - Andre P Kengne
- Non-Communicable Diseases Research Unit, South African Medical Research Council & University of Cape Town, Cape Town, South Africa.
| | - Katya L Masconi
- Department of Surgery, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa.
| | - Yandiswa Y Yako
- Department of Surgery, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa.
| | - Rajiv T Erasmus
- Division of Chemical Pathology, Faculty of Health Sciences, National Health Laboratory Service (NHLS) and University of Stellenbosch, Cape Town, South Africa.
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Hillman SL, Finer S, Smart MC, Mathews C, Lowe R, Rakyan VK, Hitman GA, Williams DJ. Novel DNA methylation profiles associated with key gene regulation and transcription pathways in blood and placenta of growth-restricted neonates. Epigenetics 2015; 10:50-61. [PMID: 25496377 PMCID: PMC4622857 DOI: 10.4161/15592294.2014.989741] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Fetal growth is determined by the feto-placental genome interacting with the maternal in utero environment. Failure of this interplay leads to poor placental development and fetal growth restriction (FGR), which is associated with future metabolic disease. We investigated whether whole genome methylation differences existed in umbilical cord blood and placenta, between gestational-matched, FGR, and appropriately grown (AGA) neonates. Using the Infinium HumanMethylation450 BeadChip®, we found that DNA from umbilical cord blood of FGR born at term (n = 19) had 839 differentially methylated positions (DMPs) that reached genome-wide significance compared with AGA (n = 18). Using gestational age as a continuous variable, we identified 76,249 DMPs in cord blood (adj. P < 0.05) of which 121 DMPs were common to the 839 DMPs and were still evident when comparing 12 FGR with 12 AGA [39.9 ± 1.2 vs. 40.0 ± 1.0 weeks (mean ± SD), respectively]. A total of 53 DMPs had a β methylation difference >10% and 25 genes were co-methylated more than twice within 1000 base pairs. Gene Ontology (GO) analysis of DMPs supported their involvement in gene regulation and transcription pathways related to organ development and metabolic function. A similar profile of DMPs was found across different cell types in the cord blood. At term, no DMPs between FGR and AGA placentae reached genome-wide significance, validated with an external dataset. GO analysis of 284 pre-term, placental DMPs associated with autophagy, oxidative stress and hormonal responses. Growth restricted neonates have distinct DNA methylation profiles in pre-term placenta and in cord blood at birth, which may predispose to future adult disease.
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Key Words
- AGA, appropriately grown offspring
- BMI, body mass index
- CG, cytosine phosphate guanine loci
- DMP, differentially methylated positions
- DNA methylation
- FDR, false discovery rate
- FGR, fetal growth restriction
- GO, gene ontology
- HOMA, homeostasis model assessment
- ICR1, imprinting control region 1
- MODY, maturity onset diabetes of the young
- Marmal-aid
- T2DM, type 2 diabetes mellitus
- UCL, University College London
- UCLH, University College London Hospital
- UCSC, University of California Santa Cruz
- fetal growth restriction
- fetal origins of adult disease
- placenta
- transcription factor
- umbilical cord
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Affiliation(s)
- Sara L Hillman
- a Institute for Women's Health ; University College London ; London , UK
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Larsen CP, Beggs ML, Saeed M, Ambruzs JM, Cossey LN, Messias NC, Walker PD, Freedman BI. Histopathologic findings associated with APOL1 risk variants in chronic kidney disease. Mod Pathol 2015; 28:95-102. [PMID: 25081748 DOI: 10.1038/modpathol.2014.92] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 05/08/2014] [Indexed: 12/22/2022]
Abstract
The effects of nephropathy risk variants in the apolipoprotein L1 gene (APOL1) on renal histopathology in African Americans with arterionephrosclerosis or putative 'hypertension-associated' nephropathy are unknown. APOL1 genotype-phenotype correlations were performed in a blinded manner from renal biopsies in 196 self-reported African Americans with arterionephrosclerosis on kidney biopsy at a large national nephropathology practice. Subjects had chronic kidney disease without nephrotic syndrome. A discovery analysis compared histopathologic changes in the glomerular and tubulointerstitial compartments in 58 subjects with 2 versus 56 subjects with 0 APOL1 risk variants. Validation was performed in biopsies from 82 additional subjects with 0, 1, and 2 risk variants. Two risk variant versus zero risk variant group genotype associations and subphenotypes were assessed by χ(2) analyses. ANOVA compared means of continuous variables. In discovery analyses, significantly less obsolescent glomerulosclerosis, more (solidified and disappearing) glomerulosclerosis, more thyroidization-type tubular atrophy, and more microcystic tubular dilatation were seen in patients with two versus zero APOL1 risk alleles. Greater degrees of arteriosclerosis were present in those with zero risk alleles. Segmental glomerulosclerosis did not differ significantly between groups. Presence of two of the following discriminatory histopathologic findings from discovery, that is, <50% obsolescent glomerulosclerosis, thyroidization-type tubular atrophy, and microcystic tubular dilatation, was specific for the presence of two APOL1 risk alleles in the validation phase. African Americans with arterionephrosclerosis who possess two APOL1 risk variants more often lack obsolescent glomerulosclerosis and have greater degrees of (solidified and disappearing) glomerulosclerosis, thyroidization-type tubular atrophy, and microcystic tubular dilation than patients with fewer than two risk variants. These findings support involvement of multiple cell types in subnephrotic forms of APOL1-associated nephropathy, particularly renal tubule cells with resultant tubulointerstitial disease.
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Affiliation(s)
| | | | | | | | | | | | | | - Barry I Freedman
- Internal Medicine-Nephrology, Wake Forest School of Medicine, Winston-Salem, NC, USA
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18
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Madhavan SM, O'Toole JF. The biology of APOL1 with insights into the association between APOL1 variants and chronic kidney disease. Clin Exp Nephrol 2014; 18:238-42. [PMID: 24233469 DOI: 10.1007/s10157-013-0907-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 10/29/2013] [Indexed: 12/15/2022]
Abstract
Recent studies have identified genetic variants in APOL1 that may contribute to the increased incidence of kidney disease in populations with African ancestry. Here, we review the biology of APOL1 present in the circulation and localized to the kidney as it may contribute to the pathogenesis of APOL1-associated kidney disease.
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19
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Ma L, Shelness GS, Snipes JA, Murea M, Antinozzi PA, Cheng D, Saleem MA, Satchell SC, Banas B, Mathieson PW, Kretzler M, Hemal AK, Rudel LL, Petrovic S, Weckerle A, Pollak MR, Ross MD, Parks JS, Freedman BI. Localization of APOL1 protein and mRNA in the human kidney: nondiseased tissue, primary cells, and immortalized cell lines. J Am Soc Nephrol 2014; 26:339-48. [PMID: 25012173 DOI: 10.1681/asn.2013091017] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Although APOL1 gene variants are associated with nephropathy in African Americans, little is known about APOL1 protein synthesis, uptake, and localization in kidney cells. To address these questions, we examined APOL1 protein and mRNA localization in human kidney and human kidney-derived cell lines. Indirect immunofluorescence microscopy performed on nondiseased nephrectomy cryosections from persons with normal kidney function revealed that APOL1 protein was markedly enriched in podocytes (colocalized with synaptopodin and Wilms' tumor suppressor) and present in lower abundance in renal tubule cells. Fluorescence in situ hybridization detected APOL1 mRNA in glomeruli (podocytes and endothelial cells) and tubules, consistent with endogenous synthesis in these cell types. When these analyses were extended to renal-derived cell lines, quantitative RT-PCR did not detect APOL1 mRNA in human mesangial cells; however, abundant levels of APOL1 mRNA were observed in proximal tubule cells and glomerular endothelial cells, with lower expression in podocytes. Western blot analysis revealed corresponding levels of APOL1 protein in these cell lines. To explain the apparent discrepancy between the marked abundance of APOL1 protein in kidney podocytes observed in cryosections versus the lesser abundance in podocyte cell lines, we explored APOL1 cellular uptake. APOL1 protein was taken up readily by human podocytes in vitro but was not taken up efficiently by mesangial cells, glomerular endothelial cells, or proximal tubule cells. We hypothesize that the higher levels of APOL1 protein in human cryosectioned podocytes may reflect both endogenous protein synthesis and APOL1 uptake from the circulation or glomerular filtrate.
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Affiliation(s)
| | | | | | | | - Peter A Antinozzi
- Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | | | - Moin A Saleem
- Children's Renal Unit, Bristol Royal Hospital for Children, University of Bristol, Bristol, United Kingdom
| | - Simon C Satchell
- Learning and Research Southmead Hospital Bristol, University of Bristol, Bristol, United Kingdom
| | - Bernhard Banas
- Internal Medicine II-Nephrology/Transplantation, University Medical Center, Regensburg, Germany
| | - Peter W Mathieson
- Children's Renal Unit, Bristol Royal Hospital for Children, University of Bristol, Bristol, United Kingdom
| | - Matthias Kretzler
- Department of Internal Medicine-Nephrology, University of Michigan at Ann Arbor Medical School, Ann Arbor, Michigan
| | | | | | - Snezana Petrovic
- Internal Medicine-Nephrology, Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | | | - Martin R Pollak
- Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts; and
| | - Michael D Ross
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts
| | - John S Parks
- Pathology-Lipid Sciences, and Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina
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Pays E, Vanhollebeke B, Uzureau P, Lecordier L, Pérez-Morga D. The molecular arms race between African trypanosomes and humans. Nat Rev Microbiol 2014; 12:575-84. [DOI: 10.1038/nrmicro3298] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Abstract
Marked familial aggregation of chronic kidney disease suggests that inherited factors play a major role in nephropathy susceptibility. Molecular genetics analyses have identified a number of genes reproducibly associated with a broad range of renal phenotypes. Most associations show polygenic inheritance patterns with limited effect size. In contrast, genetic association between the apolipoprotein L1 (APOL1) gene and several severe nondiabetic forms of kidney disease in African Americans approach Mendelian inheritance patterns and account for a large proportion of glomerulosclerosis in populations of African ancestry. Emerging data support an important role for APOL1 in the progression of diverse etiologies of kidney disease, in concert with requisite environmental (gene*environment) and inherited (gene*gene) interactions. This article reviews the current status of APOL1-associated nephropathy and discusses research questions under active investigation in the search for a cure for these severe and often progressive kidney diseases.
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Kasiske B, Saito T. The kidney and lipids: preface. Clin Exp Nephrol 2014; 18:180-4. [DOI: 10.1007/s10157-014-0954-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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23
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Sethi S, Glassock RJ, Fervenza FC. Focal segmental glomerulosclerosis: towards a better understanding for the practicing nephrologist. Nephrol Dial Transplant 2014; 30:375-84. [PMID: 24589721 DOI: 10.1093/ndt/gfu035] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Focal and segmental glomerulosclerosis (FSGS) is a common histopathological lesion that can represent a primary podocytopathy, or occur as an adaptive phenomenon consequent to nephron mass reduction, a scar from a healing vasculitic lesion, direct drug toxicity or viral infection among other secondary causes. Thus, the presence of an FSGS lesion in a renal biopsy does not confer a disease diagnosis, but rather represents the beginning of an exploratory process, hopefully leading ultimately to identification of a specific etiology and its appropriate treatment. We define primary FSGS as a 'primary' podocytopathy characterized clinically by the presence of nephrotic syndrome in a patient with an FSGS lesion on light microscopy and widespread foot process effacement on electron microscopy (EM). Secondary FSGS is commonly characterized by the absence of nephrotic syndrome and the presence of segmental foot process effacement on EM. Failure to accurately differentiate between the primary and secondary forms of FSGS has resulted in many patients undergoing unnecessary immunosuppressive treatment. Here, we review some key points that may assist the practicing nephrologist to distinguish between primary and secondary FSGS.
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Affiliation(s)
- Sanjeev Sethi
- Division of Anatomic Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | | | - Fernando C Fervenza
- Division of Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, MN, USA
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Bentley AR, Rotimi CN. Interethnic Variation in Lipid Profiles: Implications for Underidentification of African-Americans at risk for Metabolic Disorders. Expert Rev Endocrinol Metab 2014; 7:659-667. [PMID: 28191028 PMCID: PMC5298839 DOI: 10.1586/eem.12.55] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Interethnic differences exist in the distribution of serum lipids, with African Americans (AA) generally having a healthier lipid profile than other US ethnic groups. Similar lipid distributions are observed among other African ancestry groups with distinct lifestyle characteristics, suggesting the importance of inherited factors. Despite healthier serum lipids, AA experience a disproportionate burden of Type 2 Diabetes and Cardiovascular Disease. As evidence of a different relationship between serum lipids and disease exists, the characterization of metabolic risk using lipid concentration (as in Metabolic Syndrome criteria) may lead to the under-identification of AA at risk. Given the disproportionately high rate of metabolic disorders in AA, understanding interethnic differences in the association between serum lipids and disease should be a research priority, as better appreciation of these differences will enhance knowledge of disease etiology, improve intervention targeting, and may lead to mechanisms to ameliorate debilitating health disparities in the US and globally.
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Affiliation(s)
- Amy R Bentley
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Building 12A, Room 4047, 12 South Drive, Bethesda, MD, 20892 USA
| | - Charles N Rotimi
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Building 12A, Room 4047, 12 South Drive, Bethesda, MD, 20892 USA
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Bruggeman LA, O'Toole JF, Ross MD, Madhavan SM, Smurzynski M, Wu K, Bosch RJ, Gupta S, Pollak MR, Sedor JR, Kalayjian RC. Plasma apolipoprotein L1 levels do not correlate with CKD. J Am Soc Nephrol 2013; 25:634-44. [PMID: 24231663 DOI: 10.1681/asn.2013070700] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Polymorphisms in APOL1 are associated with CKD, including HIV-related CKD, in individuals of African ancestry. The apolipoprotein L1 (APOL1) protein circulates and is localized in kidney cells, but the contribution of APOL1 location to CKD pathogenesis is unclear. We examined associations of plasma APOL1 levels with plasma cytokine levels, dyslipidemia, and APOL1 genotype in a nested case-control study (n=270) of HIV-infected African Americans enrolled in a multicenter prospective observational study. Patients were designated as having CKD when estimated GFR (eGFR) decreased to <60 ml/min per 1.73 m(2) (eGFR<60 cohort) or protein-to-creatinine ratios became >3.5 g/g (nephrotic proteinuria cohort). Circulating APOL1 levels did not associate with APOL1 genotype, CKD status, or levels of proinflammatory cytokines, but did correlate with fasting cholesterol, LDL cholesterol, and triglyceride levels. At ascertainment, CKD-associated polymorphisms (risk variants) in APOL1 associated with the eGFR<60 cohort, but not the nephrotic-range proteinuria cohort. Of note, in both the eGFR<60 and nephrotic proteinuria cohorts, CKD cases with two APOL1 risk variants had significant declines in eGFR over a median of 4 years compared with individuals with one or no risk variants. APOL1 risk genotype was not associated with changes in proteinuria. Higher circulating proinflammatory cytokine levels were independently associated with CKD but not APOL1 genotype. In conclusion, the function of variant APOL1 proteins derived from circulation or synthesized in the kidney, but not the level of circulating APOL1, probably mediates APOL1-associated kidney disease in HIV-infected African Americans.
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Divers J, Núñez M, High KP, Murea M, Rocco MV, Ma L, Bowden DW, Hicks PJ, Spainhour M, Ornelles DA, Kleiboeker SB, Duncan K, Langefeld CD, Turner J, Freedman BI. JC polyoma virus interacts with APOL1 in African Americans with nondiabetic nephropathy. Kidney Int 2013; 84:1207-13. [PMID: 23677244 PMCID: PMC3844025 DOI: 10.1038/ki.2013.173] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 02/20/2013] [Accepted: 03/01/2013] [Indexed: 01/22/2023]
Abstract
Individuals with HIV infection and two apolipoprotein L1 gene (APOL1) risk variants frequently develop nephropathy. Here we tested whether non-HIV viral infections influence nephropathy risk via interactions with APOL1 by assessing APOL1 genotypes and presence of urine JC and BK polyoma virus and plasma HHV6 and CMV by quantitative polymerase chain reaction. We analyzed 300 samples from unrelated and related first-degree relatives of African Americans with non-diabetic nephropathy using linear and non-linear mixed models to account for familial relationships. The four groups evaluated were APOL1 0/1 versus 2 risk alleles, with or without nephropathy. Urine JCV and BKV were detected in 90 and 29 patients while HHV6 and CMV were rare. Adjusting for family age at nephropathy, gender and ancestry, presence of JCV genomic DNA in urine and APOL1 risk alleles were significantly negatively associated with elevated serum cystatin C, albuminuria (albumin to creatinine ratio over 30 mg/g), and kidney disease defined as an eGFR under 60 ml/min per 1.73 m2 and/or albuminuria in an additive (APOL1 plus JCV) model. BK viruria was not associated with kidney disease. Thus, African Americans at increased risk for APOL1-associated nephropathy (two APOL1 risk variants) with JC viruria had a lower prevalence of kidney disease, suggesting that JCV interaction with APOL1 genotype may influence kidney disease risk.
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Affiliation(s)
- Jasmin Divers
- Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
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Pirkle JL, Freedman BI. Hypertension and chronic kidney disease: controversies in pathogenesis and treatment. MINERVA UROL NEFROL 2013; 65:37-50. [PMID: 23538309 PMCID: PMC4030753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The relationship between hypertension and chronic kidney disease (CKD) has long been the subject of controversy. The pathogenetic mechanisms of nephropathy in non-diabetic individuals with hypertension, as well as optimal hypertension treatment targets in populations with nephropathy remain important clinical concerns. This manuscript reviews breakthroughs in molecular genetics that have clarified the complex relationship between hypertension and kidney disease, answering the question of which factor comes first. An overview of the potential roles that hyperuricemia plays in the pathogenesis of hypertension and CKD and current blood pressure treatment guidelines in populations with CKD are discussed. The ongoing National Institutes of Health-sponsored Systolic Blood Pressure Intervention Trial (SPRINT) is underway to help answer these important questions. Enrollment of 9250 hypertensive SPRINT participants will be completed in 2013; important results on ideal blood pressure control targets for reducing nephropathy progression, cardiovascular disease end-points, and preserving cognitive function are expected. As such, many of the controversial aspects of hypertension management will likely be clarified in the near future.
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Affiliation(s)
- James L. Pirkle
- Department of Internal Medicine, Section on Nephrology; Wake Forest School of Medicine; Winston-Salem, North Carolina, USA
| | - Barry I. Freedman
- Department of Internal Medicine, Section on Nephrology; Wake Forest School of Medicine; Winston-Salem, North Carolina, USA
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Lopez-Hellin J, Cantarell C, Jimeno L, Sanchez-Fructuoso A, Puig-Gay N, Guirado L, Vilariño N, Gonzalez-Roncero FM, Mazuecos A, Lauzurica R, Burgos D, Plumed JS, Jacobs-Cacha C, Jimenez C, Fernandez A, Fernandez-Alvarez P, Torregrosa V, Nieto JL, Meseguer A, Alonso A. A form of apolipoprotein a-I is found specifically in relapses of focal segmental glomerulosclerosis following transplantation. Am J Transplant 2013; 13:493-500. [PMID: 23205849 DOI: 10.1111/j.1600-6143.2012.04338.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 09/21/2012] [Accepted: 10/13/2012] [Indexed: 01/25/2023]
Abstract
Recurrence of idiopathic focal segmental glomerulosclerosis (FSGS) following kidney transplantation occurs in a large percentage of patients. Accurate prediction of recurrence and elucidation of its pathogenesis are major therapeutic goals. To detect differential proteins related to FSGS recurrence, proteomic analysis was performed on plasma and urine samples from 35 transplanted idiopathic FSGS patients, divided into relapsing and nonrelapsing. Several proteins were detected increased in urine of relapsing FSGS patients, including a high molecular weight form of apolipoprotein A-I, named ApoA-Ib, found exclusively in relapsing patients. This finding was verified by Western blot individually in the 35 patients and validated in an independent group of 40 patients with relapsing or nonrelapsing FSGS, plus two additional groups: FSGS-unrelated patients showing different proteinuria levels (n = 30), and familial FSGS transplanted patients (n = 14). In the total of 119 patients studied, the ApoA-Ib form was detected in 13 of the 14 relapsing FSGS patients, and in one of the 61 nonrelapsing patients. Only one of the 30 patients with FSGS-unrelated proteinuria tested positive for ApoA-Ib, and was not detected in familial patients. Urinary ApoA-Ib is associated with relapses in idiopathic FSGS and warrants additional investigation to determine its usefulness as biomarker of relapse following transplantation.
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Affiliation(s)
- J Lopez-Hellin
- Kidney Pathophysiology, CIBBIM-Nanomedicine, Hospital Universitari Vall d'Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain.
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Variation in APOL1 Contributes to Ancestry-Level Differences in HDLc-Kidney Function Association. Int J Nephrol 2012; 2012:748984. [PMID: 22973513 PMCID: PMC3438781 DOI: 10.1155/2012/748984] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 06/26/2012] [Accepted: 07/11/2012] [Indexed: 12/31/2022] Open
Abstract
Low levels of high-density cholesterol (HDLc) accompany chronic kidney disease, but the association between HDLc and the estimated glomerular filtration rate (eGFR) in the general population is unclear. We investigated the HDLc-eGFR association in nondiabetic Han Chinese (HC, n = 1100), West Africans (WA, n = 1497), and African Americans (AA, n = 1539). There were significant differences by ancestry: HDLc was positively associated with eGFR in HC (β = 0.13, P < 0.0001), but negatively associated among African ancestry populations (WA: -0.19, P < 0.0001; AA: -0.09, P = 0.02). These differences were also seen in nationally-representative NHANES data (among European Americans: 0.09, P = 0.005; among African Americans -0.14, P = 0.03). To further explore the findings in African ancestry populations, we investigated the role of an African ancestry-specific nephropathy risk variant, rs73885319, in the gene encoding HDL-associated APOL1. Among AA, an inverse HDLc-eGFR association was observed only with the risk genotype (-0.38 versus 0.001; P = 0.03). This interaction was not seen in WA. In summary, counter to expectation, an inverse HDLc-eGFR association was observed among those of African ancestry. Given the APOL1 × HDLc interaction among AA, genetic factors may contribute to this paradoxical association. Notably, these findings suggest that the unexplained mechanism by which APOL1 affects kidney-disease risk may involve HDLc.
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Association of APOL1 variants with mild kidney disease in the first-degree relatives of African American patients with non-diabetic end-stage renal disease. Kidney Int 2012; 82:805-11. [PMID: 22695330 PMCID: PMC3443536 DOI: 10.1038/ki.2012.217] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Familial aggregation of non-diabetic end stage renal disease (ESRD) is found in African Americans and variants in the apolipoprotein L1 gene (APOL1) contribute to this risk. To detect genetic associations with milder forms of nephropathy in high-risk families, analyses were performed using generalized estimating equations to assess relationships between kidney disease phenotypes and APOL1 variants in 786 relatives of 470 families. Adjusting for familial correlations, 23.1, 46.7, and 30.2 percent of genotyped relatives possessed two, one, or no APOL1 risk variants, respectively. Relatives with two compared to one or no risk variants had statistically indistinguishable median systolic blood pressure, urine albumin to creatinine ratio, estimated GFR (MDRD equation) and serum cystatin C levels. After adjusting for age, gender, age at ESRD in families, and African ancestry, significant associations were detected between APOL1 with overt proteinuria and estimated GFR (CKD-EPI equation), with a trend toward significance for quantitative albuminuria. Thus, relatives of African Americans with non-diabetic ESRD are enriched for APOL1 risk variants. After adjustment, two APOL1 risk variants weakly predict mild forms of kidney disease. Second hits appear necessary for the initiation of APOL1-associated nephropathy.
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Abstract
Apolipoprotein L1 (APOL1) gene association studies and results of the African American Study of Kidney Disease and Hypertension are disproving the longstanding concept that mild to moderate essential hypertension contributes substantially to end-stage renal disease susceptibility in African Americans. APOL1 coding variants underlie a spectrum of kidney diseases, including that attributed to hypertension (labeled arteriolar or hypertensive nephrosclerosis), focal segmental glomerulosclerosis, and HIV-associated nephropathy. APOL1 nephropathy risk variants persist because of protection afforded from the parasite that causes African sleeping sickness. This breakthrough will lead to novel treatments for hypertensive African Americans with low-level proteinuria, for whom effective therapies are lacking. Furthermore, APOL1 nephropathy risk variants contribute to racially variable allograft survival rates after kidney transplantation and assist in detecting nondiabetic forms of nephropathy in African Americans with diabetes. Discovery of APOL1-associated nephropathy was a major success of the genetics revolution, demonstrating that secondary hypertension is typically present in nondiabetic African Americans with nephropathy.
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Freedman BI, Langefeld CD. The new era of APOL1-associated glomerulosclerosis. Nephrol Dial Transplant 2012; 27:1288-91. [PMID: 22302261 DOI: 10.1093/ndt/gfr812] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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