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Mollusc N-glycosylation: Structures, Functions and Perspectives. Biomolecules 2021; 11:biom11121820. [PMID: 34944464 PMCID: PMC8699351 DOI: 10.3390/biom11121820] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/01/2021] [Accepted: 12/01/2021] [Indexed: 12/22/2022] Open
Abstract
Molluscs display a sophisticated N-glycan pattern on their proteins, which is, in terms of involved structural features, even more diverse than that of vertebrates. This review summarises the current knowledge of mollusc N-glycan structures, with a focus on the functional aspects of the corresponding glycoproteins. Furthermore, the potential of mollusc-derived biomolecules for medical applications is addressed, emphasising the importance of mollusc research.
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Ohyama Y, Renfrow MB, Novak J, Takahashi K. Aberrantly Glycosylated IgA1 in IgA Nephropathy: What We Know and What We Don't Know. J Clin Med 2021; 10:jcm10163467. [PMID: 34441764 PMCID: PMC8396900 DOI: 10.3390/jcm10163467] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/26/2021] [Accepted: 08/02/2021] [Indexed: 12/17/2022] Open
Abstract
IgA nephropathy (IgAN), the most common primary glomerular disease worldwide, is characterized by glomerular deposition of IgA1-containing immune complexes. The IgA1 hinge region (HR) has up to six clustered O-glycans consisting of Ser/Thr-linked N-acetylgalactosamine usually with β1,3-linked galactose and variable sialylation. Circulating levels of IgA1 with abnormally O-glycosylated HR, termed galactose-deficient IgA1 (Gd-IgA1), are increased in patients with IgAN. Current evidence suggests that IgAN is induced by multiple sequential pathogenic steps, and production of aberrantly glycosylated IgA1 is considered the initial step. Thus, the mechanisms of biosynthesis of aberrantly glycosylated IgA1 and the involvement of aberrant glycoforms of IgA1 in disease development have been studied. Furthermore, Gd-IgA1 represents an attractive biomarker for IgAN, and its clinical significance is still being evaluated. To elucidate the pathogenesis of IgAN, it is important to deconvolute the biosynthetic origins of Gd-IgA1 and characterize the pathogenic IgA1 HR O-glycoform(s), including the glycan structures and their sites of attachment. These efforts will likely lead to development of new biomarkers. Here, we review the IgA1 HR O-glycosylation in general and the role of aberrantly glycosylated IgA1 in the pathogenesis of IgAN in particular.
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Affiliation(s)
- Yukako Ohyama
- Department of Biomedical Molecular Sciences, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan;
| | - Matthew B. Renfrow
- Departments of Biochemistry and Molecular Genetics and Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (M.B.R.); (J.N.)
| | - Jan Novak
- Departments of Biochemistry and Molecular Genetics and Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (M.B.R.); (J.N.)
| | - Kazuo Takahashi
- Department of Biomedical Molecular Sciences, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan;
- Correspondence: ; Tel.: +81-(562)-93-2430; Fax: +81-(562)-93-1830
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Hansen AL, Reily C, Novak J, Renfrow MB. Immunoglobulin A Glycosylation and Its Role in Disease. EXPERIENTIA SUPPLEMENTUM (2012) 2021; 112:433-477. [PMID: 34687019 DOI: 10.1007/978-3-030-76912-3_14] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Human IgA is comprised of two subclasses, IgA1 and IgA2. Monomeric IgA (mIgA), polymeric IgA (pIgA), and secretory IgA (SIgA) are the main molecular forms of IgA. The production of IgA rivals all other immunoglobulin isotypes. The large quantities of IgA reflect the fundamental roles it plays in immune defense, protecting vulnerable mucosal surfaces against invading pathogens. SIgA dominates mucosal surfaces, whereas IgA in circulation is predominately monomeric. All forms of IgA are glycosylated, and the glycans significantly influence its various roles, including antigen binding and the antibody effector functions, mediated by the Fab and Fc portions, respectively. In contrast to its protective role, the aberrant glycosylation of IgA1 has been implicated in the pathogenesis of autoimmune diseases, such as IgA nephropathy (IgAN) and IgA vasculitis with nephritis (IgAVN). Furthermore, detailed characterization of IgA glycosylation, including its diverse range of heterogeneity, is of emerging interest. We provide an overview of the glycosylation observed for each subclass and molecular form of IgA as well as the range of heterogeneity for each site of glycosylation. In many ways, the role of IgA glycosylation is in its early stages of being elucidated. This chapter provides an overview of the current knowledge and research directions.
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Affiliation(s)
- Alyssa L Hansen
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Colin Reily
- Departments of Medicine and Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Matthew B Renfrow
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA.
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Pietrzyk-Brzezinska AJ, Bujacz A. H-type lectins - Structural characteristics and their applications in diagnostics, analytics and drug delivery. Int J Biol Macromol 2020; 152:735-747. [PMID: 32119947 DOI: 10.1016/j.ijbiomac.2020.02.320] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/27/2020] [Accepted: 02/27/2020] [Indexed: 12/15/2022]
Abstract
Lectins are ubiquitous carbohydrate-binding proteins that interact with sugar moieties in a highly specific manner. H-type lectins represent a new group of lectins that were identified in invertebrates. These lectins share structural homology and bind mainly to N-acetylgalactosamine (GalNAc). Recent structural studies on the H-type lectins provided a detailed description of the GalNAc-lectin interaction that is already exploited in a number of biomedical applications. Two members of the H-type lectin family, Helix pomatia agglutinin (HPA) and Helix aspersa agglutinin (HAA), have already been extensively used in many diagnostic tests due their ability to specifically recognize GalNAc. This ability is especially important because aberrant glycosylation patterns of proteins expressed by cancer cells contain GalNAc. In addition, H-type lectins were utilized in diagnostics of other non-cancer diseases and represent great potential as components of drug delivery systems. Here, we present an overview of the H-type lectins and their applications in diagnostics, analytics and drug delivery.
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Affiliation(s)
- Agnieszka J Pietrzyk-Brzezinska
- Institute of Molecular and Industrial Biotechnology, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, Stefanowskiego 4/10, Lodz 90-924, Poland.
| | - Anna Bujacz
- Institute of Molecular and Industrial Biotechnology, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, Stefanowskiego 4/10, Lodz 90-924, Poland
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Yamasaki K, Suzuki H, Yasutake J, Yamazaki Y, Suzuki Y. Galactose-Deficient IgA1-Specific Antibody Recognizes GalNAc-Modified Unique Epitope on Hinge Region of IgA1. Monoclon Antib Immunodiagn Immunother 2018; 37:252-256. [PMID: 30570353 PMCID: PMC6338562 DOI: 10.1089/mab.2018.0041] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Galactose-deficient IgA1 (Gd-IgA1) that exposes GalNAc or sialylated GalNAc has been shown to be associated with disease activity of IgA nephropathy (IgAN). In a previous report, we established an enzyme-linked immunosorbent assay that measures human Gd-IgA1 using a specific monoclonal antibody KM55 (KM55 mAb), and showed that patients with IgAN contain a higher level of serum Gd-IgA1 than other types of renal diseases. Recently, we also found that the KM55 mAb specifically recognized the glomerular-deposited Gd-IgA1 in renal biopsy. In this study, we aimed to analyze the epitope of KM55 mAb using synthesized peptides corresponding to the hinge region of IgA1 with GalNAc moiety on putative glycosylated Ser/Thr residues, which are Thr225, Thr228, Ser230, Ser232, and Thr236. Binding analysis to single GalNAc-modified hinge region peptide of IgA1 showed that Thr225 with GalNAc is required for recognition of KM55. PST(GalNAC)PP motif was required for KM55 mAb to recognize hinge region peptide of IgA1 which is shown by binding assay with deletion peptide. This result was confirmed by binding of KM55 mAb against peptide with GalNAc at Thr233, which resulted in containing another PST(GalNAC)PP motif. Taken together, we concluded that the epitope of Gd-IgA1-specific KM55 mAb is PST(GalNAc)PP motif.
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Affiliation(s)
- Kohei Yamasaki
- 1 Department of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan.,2 Nephrology R&D Unit, Kyowa Hakko Kirin Co., Ltd., Tokyo, Japan
| | - Hitoshi Suzuki
- 1 Department of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Junichi Yasutake
- 2 Nephrology R&D Unit, Kyowa Hakko Kirin Co., Ltd., Tokyo, Japan
| | - Yuji Yamazaki
- 2 Nephrology R&D Unit, Kyowa Hakko Kirin Co., Ltd., Tokyo, Japan
| | - Yusuke Suzuki
- 1 Department of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
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FcαRI binding at the IgA1 C H2-C H3 interface induces long-range conformational changes that are transmitted to the hinge region. Proc Natl Acad Sci U S A 2018; 115:E8882-E8891. [PMID: 30181292 DOI: 10.1073/pnas.1807478115] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
IgA effector functions include proinflammatory immune responses triggered upon clustering of the IgA-specific receptor, FcαRI, by IgA immune complexes. FcαRI binds to the IgA1-Fc domain (Fcα) at the CH2-CH3 junction and, except for CH2 L257 and L258, all side-chain contacts are contributed by the CH3 domain. In this study, we used experimental and computational approaches to elucidate energetic and conformational aspects of FcαRI binding to IgA. The energetic contribution of each IgA residue in the binding interface was assessed by alanine-scanning mutagenesis and equilibrium surface plasmon resonance (SPR). As expected, hydrophobic residues central to the binding site have strong energetic contributions to the FcαRI:Fcα interaction. Surprisingly, individual mutation of CH2 residues L257 and L258, found at the periphery of the FcαRI binding site, dramatically reduced binding affinity. Comparison of antibody:receptor complexes involving IgA or its precursor IgY revealed a conserved receptor binding site at the CH2-CH3 junction (or its equivalent). Given the importance of residues near the CH2-CH3 junction, we used coarse-grained Langevin dynamics simulations to understand the functional dynamics in Fcα. Our simulations indicate that FcαRI binding, either in an asymmetric (1:1) or symmetric (2:1) complex with Fcα, propagated long-range conformational changes across the Fc domains, potentially impacting the hinge and Fab regions. Subsequent SPR experiments confirmed that FcαRI binding to the Fcα CH2-CH3 junction altered the kinetics of HAA lectin binding at the IgA1 hinge. Receptor-induced long-distance conformational transitions have important implications for the interaction of aberrantly glycosylated IgA1 with anti-glycan autoantibodies in IgA nephropathy.
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Abstract
IgA nephropathy, the most common primary glomerulonephritis in the world and a frequent cause of end-stage renal disease, is characterized by typical mesangial deposits of IgA1, as described by Berger and Hinglaise in 1968. Since then, it has been discovered that aberrant IgA1 O-glycosylation is involved in disease pathogenesis. Progress in glycomic, genomic, clinical, analytical, and biochemical studies has shown autoimmune features of IgA nephropathy. The autoimmune character of the disease is explained by a multihit pathogenesis model, wherein overproduction of aberrantly glycosylated IgA1, galactose-deficient in some O-glycans, by IgA1-secreting cells leads to increased levels of circulatory galactose-deficient IgA1. These glycoforms induce production of autoantibodies that subsequently bind hinge-region of galactose-deficient IgA1 molecules, resulting in the formation of nephritogenic immune complexes. Some of these complexes deposit in the kidney, activate mesangial cells, and incite glomerular injury. Thus, galactose-deficient IgA1 is central to the disease process. In this article, we review studies concerning IgA1 O-glycosylation that have contributed to the current understanding of the role of IgA1 in the pathogenesis of IgA nephropathy.
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Affiliation(s)
- Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL..
| | - Jonathan Barratt
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
| | - Bruce A Julian
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL.; Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Matthew B Renfrow
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL
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Elevated Plasma α-Defensins (HNP1-3) Levels Correlated with IgA1 Glycosylation and Susceptibility to IgA Nephropathy. DISEASE MARKERS 2016; 2016:8123138. [PMID: 27563166 PMCID: PMC4985581 DOI: 10.1155/2016/8123138] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 06/11/2016] [Accepted: 06/22/2016] [Indexed: 11/27/2022]
Abstract
Aim. IgA nephropathy (IgAN) is the most common form of glomerulonephritis. Recent genome-wide association study (GWAS) suggested that DEFA locus (which encodes α-defensins) may play a key role in IgAN. Methods. The levels of α-defensins in 169 IgAN patients and 83 healthy controls were tested by ELISA. Results. We observed that α-defensins human neutrophil peptides 1–3 (HNP1–3) in IgAN patients were elevated compared with healthy controls. The mean levels of α-defensins of 83 healthy controls and 169 IgAN patients were 50 ng/mL and 78.42 ng/mL. When the results were adjusted to the mean levels of α-defensins of IgAN patients, the percentage of individuals with high levels of α-defensins increased in IgAN patients (22.5%) compared to healthy controls (9.6%) (p = 0.013). The elevation of α-defensins in IgAN patients was independent of renal function or neutrophil count, which were major sources of α-defensins in circulation. More importantly, negative correlation was observed between galactose-deficient IgA1and α-defensins. Conclusion. As α-defensin is a lectin-like peptide, we speculated that it might be involved in IgA galactose deficiency. The data implied that patients with IgAN had higher plasma α-defensins levels and high α-defensins correlated with IgA galactose deficiency, further suggesting a pathogenic role of α-defensins in IgAN.
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Knoppova B, Reily C, Maillard N, Rizk DV, Moldoveanu Z, Mestecky J, Raska M, Renfrow MB, Julian BA, Novak J. The Origin and Activities of IgA1-Containing Immune Complexes in IgA Nephropathy. Front Immunol 2016; 7:117. [PMID: 27148252 PMCID: PMC4828451 DOI: 10.3389/fimmu.2016.00117] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 03/15/2016] [Indexed: 12/12/2022] Open
Abstract
IgA nephropathy (IgAN) is the most common primary glomerulonephritis, frequently leading to end-stage renal disease, as there is no disease-specific therapy. IgAN is diagnosed from pathological assessment of a renal biopsy specimen based on predominant or codominant IgA-containing immunodeposits, usually with complement C3 co-deposits and with variable presence of IgG and/or IgM. The IgA in these renal deposits is galactose-deficient IgA1, with less than a full complement of galactose residues on the O-glycans in the hinge region of the heavy chains. Research from the past decade led to the definition of IgAN as an autoimmune disease with a multi-hit pathogenetic process with contributing genetic and environmental components. In this process, circulating galactose-deficient IgA1 (autoantigen) is bound by antiglycan IgG or IgA (autoantibodies) to form immune complexes. Some of these circulating complexes deposit in glomeruli, and thereby activate mesangial cells and induce renal injury through cellular proliferation and overproduction of extracellular matrix components and cytokines/chemokines. Glycosylation pathways associated with production of the autoantigen and the unique characteristics of the corresponding autoantibodies in patients with IgAN have been uncovered. Complement likely plays a significant role in the formation and the nephritogenic activities of these complexes. Complement activation is mediated through the alternative and lectin pathways and probably occurs systemically on IgA1-containing circulating immune complexes as well as locally in glomeruli. Incidence of IgAN varies greatly by geographical location; the disease is rare in central Africa but accounts for up to 40% of native-kidney biopsies in eastern Asia. Some of this variation may be explained by genetically determined influences on the pathogenesis of the disease. Genome-wide association studies to date have identified several loci associated with IgAN. Some of these loci are associated with the increased prevalence of IgAN, whereas others, such as deletion of complement factor H-related genes 1 and 3, are protective against the disease. Understanding the molecular mechanisms and genetic and biochemical factors involved in formation and activities of pathogenic IgA1-containing immune complexes will enable the development of future disease-specific therapies as well as identification of non-invasive disease-specific biomarkers.
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Affiliation(s)
- Barbora Knoppova
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Immunology, Faculty of Medicine and Dentistry, Palacky University and University Hospital, Olomouc, Czech Republic
| | - Colin Reily
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Nicolas Maillard
- Université Jean Monnet, Saint Etienne, France
- PRES Université de Lyon, Lyon, France
| | - Dana V. Rizk
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Zina Moldoveanu
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jiri Mestecky
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Milan Raska
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Immunology, Faculty of Medicine and Dentistry, Palacky University and University Hospital, Olomouc, Czech Republic
| | - Matthew B. Renfrow
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Bruce A. Julian
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
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Pietrzyk AJ, Bujacz A, Mak P, Potempa B, Niedziela T. Structural studies of Helix aspersa agglutinin complexed with GalNAc: A lectin that serves as a diagnostic tool. Int J Biol Macromol 2015; 81:1059-68. [PMID: 26416237 DOI: 10.1016/j.ijbiomac.2015.09.044] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Revised: 09/22/2015] [Accepted: 09/23/2015] [Indexed: 02/07/2023]
Abstract
Lectins belong to a differentiated group of proteins known to possess sugar-binding properties. Due to this fact, they are interesting research targets in medical diagnostics. Helix aspersa agglutinin (HAA) is a lectin that recognizes the epitopes containing α-d-N-acetylgalactosamine (GalNAc), which is present at the surface of metastatic cancer cells. Although several reports have already described the use of HAA as a diagnostic tool, this protein was not characterized on the molecular level. Here, we present for the first time the structural information about lectin isolated from mucus of Helix aspersa (garden snail). The amino acid sequence of this agglutinin was determined by Edman degradation and tertiary as well as quaternary structure by X-ray crystallography. The high resolution crystal structure (1.38Å) and MALDI-TOF mass spectrometry analysis provide the detailed information about a large part of the HAA natural glycan chain. The topology of the GalNAc binding cleft and interaction with lectin are very well defined in the structure and fully confirmed by STD HSQC NMR spectroscopy. Together, this provides structural clues regarding HAA specificity and opens possibilities to rational modifications of this important diagnostic tool.
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Affiliation(s)
- Agnieszka J Pietrzyk
- Institute of Technical Biochemistry, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, Stefanowskiego 4/10, Lodz 90-924, Poland
| | - Anna Bujacz
- Institute of Technical Biochemistry, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, Stefanowskiego 4/10, Lodz 90-924, Poland.
| | - Paweł Mak
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7A, 30-387 Krakow, Poland; Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland
| | - Barbara Potempa
- University of Louisville School of Dentistry, Department of Oral Immunology and Infectious Diseases, 501 South Preston Street, Louisville, KY 40202, USA
| | - Tomasz Niedziela
- Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Rudolfa Weigla 12, Wrocław 53-114, Poland
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The solution structures of native and patient monomeric human IgA1 reveal asymmetric extended structures: implications for function and IgAN disease. Biochem J 2015; 471:167-85. [PMID: 26268558 PMCID: PMC4692083 DOI: 10.1042/bj20150612] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 08/12/2015] [Indexed: 01/14/2023]
Abstract
Detailed analytical ultracentrifugation and X-ray/neutron scattering data and a new atomistic modelling approach revealed asymmetric extended solution structures for human IgA1 that account for its receptor-binding function. IgA1 with different hinge O-galactosylation patterns showed similar structures. Native IgA1, for which no crystal structure is known, contains an O-galactosylated 23-residue hinge region that joins its Fab and Fc regions. IgA nephropathy (IgAN) is a leading cause of chronic kidney disease in developed countries. Because IgA1 in IgAN often has a poorly O-galactosylated hinge region, the solution structures of monomeric IgA1 from a healthy subject and three IgAN patients with four different O-galactosylation levels were studied. Analytical ultracentrifugation showed that all four IgA1 samples were monomeric with similar sedimentation coefficients, s020,w. X-ray scattering showed that the radius of gyration (Rg) slightly increased with IgA1 concentration, indicating self-association, although their distance distribution curves, P(r), were unchanged with concentration. Neutron scattering indicated similar Rg values and P(r) curves, although IgA1 showed a propensity to aggregate in heavy water buffer. A new atomistic modelling procedure based on comparisons with 177000 conformationally-randomized IgA1 structures with the individual experimental scattering curves revealed similar extended Y-shaped solution structures for all four differentially-glycosylated IgA1 molecules. The final models indicated that the N-glycans at Asn263 were folded back against the Fc surface, the C-terminal tailpiece conformations were undefined and hinge O-galactosylation had little effect on the solution structure. The solution structures for full-length IgA1 showed extended hinges and the Fab and Fc regions were positioned asymmetrically to provide ample space for the functionally-important binding of two FcαR receptors to its Fc region. Whereas no link between O-galactosylation and the IgA1 solution structure was detected, an increase in IgA1 aggregation with reduced O-galactosylation may relate to IgAN.
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Yasutake J, Suzuki Y, Suzuki H, Hiura N, Yanagawa H, Makita Y, Kaneko E, Tomino Y. Novel lectin-independent approach to detect galactose-deficient IgA1 in IgA nephropathy. Nephrol Dial Transplant 2015; 30:1315-21. [PMID: 26109484 PMCID: PMC4513896 DOI: 10.1093/ndt/gfv221] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 04/16/2015] [Indexed: 12/15/2022] Open
Abstract
Background Galactose-deficient IgA1 (Gd-IgA1) is a critical effector molecule in the pathogenesis of IgA nephropathy (IgAN). Although many researchers have measured serum levels of Gd-IgA1 using snail helix aspersa agglutinin (HAA) lectin-based assay, the lectin-dependent assay has some serious problems in robustness. In this study, we aimed to establish a more robust and stable enzyme-linked immunosorbent assay (ELISA) method that uses a specific monoclonal antibody to recognize a hinge region in human Gd-IgA1 (Gd-IgA1 ELISA). Methods Rats were immunized with human Gd-IgA1 hinge region peptide to obtain Gd-IgA1-specific monoclonal antibody KM55. Gd-IgA1 ELISA for specifically detecting serum Gd-IgA1 was consequently constructed. Serum Gd-IgA1 concentrations in human subjects were measured using KM55 ELISA assay. To further confirm specificity of the Gd-IgA1-specific antibody, KM55 was also applied for immunofluorescence staining of glomerular Gd-IgA1 in paraffin-embedded sections of renal biopsy specimens. Results Measurement of serum levels of Gd-IgA1 in human subjects by Gd-IgA1 ELISA revealed increased serum Gd-IgA1 level in patients with IgAN compared with patients with other renal diseases or non-renal diseases. Importantly, the results obtained from Gd-IgA1 ELISA positively correlated with those from the HAA lectin-based assay (R = 0.75). Immunofluorescence staining of renal biopsy specimens with KM55 detected glomerular co-localization of Gd-IgA1 and IgA. Conclusion This novel lectin-independent method with KM55 for measuring serum levels of Gd-IgA1 can pave the way for more convincing diagnosis and activity assessment of IgAN, and can expedite clinical research to better understand this difficult disease.
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Affiliation(s)
- Junichi Yasutake
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan Kyowa Hakko Kirin Co., Ltd, Tokyo Japan
| | - Yusuke Suzuki
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Hitoshi Suzuki
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Naoko Hiura
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan Kyowa Hakko Kirin Co., Ltd, Tokyo Japan
| | - Hiroyuki Yanagawa
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Yuko Makita
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | | | - Yasuhiko Tomino
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
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Coppo R. A new monoclonal antibody for detecting degalactosylated IgA1 as serum biomarker of IgA nephropathy. Nephrol Dial Transplant 2015; 30:1234-6. [DOI: 10.1093/ndt/gfv234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2015] [Indexed: 12/19/2022] Open
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14
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Novak J, Raska M, Mestecky J, Julian BA. IgA Nephropathy and Related Diseases. Mucosal Immunol 2015. [DOI: 10.1016/b978-0-12-415847-4.00105-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Abstract
PURPOSE OF REVIEW In this article, we review recent findings on the pathogenesis and genetics of immunoglobulin A (IgA) nephropathy. RECENT FINDINGS During the past 2 years, the understanding of the pathogenesis of IgA nephropathy has evolved as a result of progress in technology and new tools that have been developed. Since 1968, when IgA nephropathy was described as an IgA-IgG immune-complex disease, the knowledge base expanded to allow definition of IgA nephropathy as an autoimmune disease with a multihit pathogenetic process. Specifically, galactose-deficient immunoglobulin A1 (IgA1) is recognized by unique autoantibodies, resulting in the formation of pathogenic immune complexes that ultimately deposit in the glomerular mesangium and induce renal injury. New approaches using high-resolution mass spectrometry have provided unique insight at the molecular level into IgA1 O-glycosylation. Cutting-edge genome-wide association studies revealed multiple disease-associated risk loci and have mapped their geographic and racial distribution. SUMMARY Recent studies of molecular and genetic defects operating in IgA nephropathy can define new biomarkers specific for the disease that can be developed into clinical assays to aid in the diagnosis, assessment of prognosis, and monitoring of disease progression. Moreover, disease-specific targets are being discovered that may lead to development of new approaches for treatment.
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Suzuki H, Raska M, Yamada K, Moldoveanu Z, Julian BA, Wyatt RJ, Tomino Y, Gharavi AG, Novak J. Cytokines alter IgA1 O-glycosylation by dysregulating C1GalT1 and ST6GalNAc-II enzymes. J Biol Chem 2014; 289:5330-9. [PMID: 24398680 PMCID: PMC3931088 DOI: 10.1074/jbc.m113.512277] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
IgA nephropathy (IgAN), the most common primary glomerulonephritis, is characterized by renal immunodeposits containing IgA1 with galactose-deficient O-glycans (Gd-IgA1). These immunodeposits originate from circulating immune complexes consisting of anti-glycan antibodies bound to Gd-IgA1. As clinical disease onset and activity of IgAN often coincide with mucosal infections and dysregulation of cytokines, we hypothesized that cytokines may affect IgA1 O-glycosylation. We used IgA1-secreting cells derived from the circulation of IgAN patients and healthy controls and assessed whether IgA1 O-glycosylation is altered by cytokines. Of the eight cytokines tested, only IL-6 and, to a lesser degree, IL-4 significantly increased galactose deficiency of IgA1; changes in IgA1 O-glycosylation were robust for the cells from IgAN patients. These cytokines reduced galactosylation of the O-glycan substrate directly via decreased expression of the galactosyltransferase C1GalT1 and, indirectly, via increased expression of the sialyltransferase ST6GalNAc-II, which prevents galactosylation by C1GalT1. These findings were confirmed by siRNA knockdown of the corresponding genes and by in vitro enzyme reactions. In summary, IL-6 and IL-4 accentuated galactose deficiency of IgA1 via coordinated modulation of key glycosyltransferases. These data provide a mechanism explaining increased immune-complex formation and disease exacerbation during mucosal infections in IgAN patients.
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Affiliation(s)
- Hitoshi Suzuki
- From the University of Alabama at Birmingham, Birmingham, Alabama 35294
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17
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Gerlach JQ, Krüger A, Gallogly S, Hanley SA, Hogan MC, Ward CJ, Joshi L, Griffin MD. Surface glycosylation profiles of urine extracellular vesicles. PLoS One 2013; 8:e74801. [PMID: 24069349 PMCID: PMC3777961 DOI: 10.1371/journal.pone.0074801] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 08/02/2013] [Indexed: 12/12/2022] Open
Abstract
Urinary extracellular vesicles (uEVs) are released by cells throughout the nephron and contain biomolecules from their cells of origin. Although uEV-associated proteins and RNA have been studied in detail, little information exists regarding uEV glycosylation characteristics. Surface glycosylation profiling by flow cytometry and lectin microarray was applied to uEVs enriched from urine of healthy adults by ultracentrifugation and centrifugal filtration. The carbohydrate specificity of lectin microarray profiles was confirmed by competitive sugar inhibition and carbohydrate-specific enzyme hydrolysis. Glycosylation profiles of uEVs and purified Tamm Horsfall protein were compared. In both flow cytometry and lectin microarray assays, uEVs demonstrated surface binding, at low to moderate intensities, of a broad range of lectins whether prepared by ultracentrifugation or centrifugal filtration. In general, ultracentrifugation-prepared uEVs demonstrated higher lectin binding intensities than centrifugal filtration-prepared uEVs consistent with lesser amounts of co-purified non-vesicular proteins. The surface glycosylation profiles of uEVs showed little inter-individual variation and were distinct from those of Tamm Horsfall protein, which bound a limited number of lectins. In a pilot study, lectin microarray was used to compare uEVs from individuals with autosomal dominant polycystic kidney disease to those of age-matched controls. The lectin microarray profiles of polycystic kidney disease and healthy uEVs showed differences in binding intensity of 6/43 lectins. Our results reveal a complex surface glycosylation profile of uEVs that is accessible to lectin-based analysis following multiple uEV enrichment techniques, is distinct from co-purified Tamm Horsfall protein and may demonstrate disease-specific modifications.
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Affiliation(s)
- Jared Q. Gerlach
- Regenerative Medicine Institute (REMEDI), National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland
- Glycoscience Group, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland
| | - Anja Krüger
- Regenerative Medicine Institute (REMEDI), National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland
- Glycoscience Group, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland
| | - Susan Gallogly
- Regenerative Medicine Institute (REMEDI), National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland
| | - Shirley A. Hanley
- Regenerative Medicine Institute (REMEDI), National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland
| | - Marie C. Hogan
- Dept. of Medicine, Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Christopher J. Ward
- Dept. of Medicine, Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Lokesh Joshi
- Glycoscience Group, National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland
| | - Matthew D. Griffin
- Regenerative Medicine Institute (REMEDI), National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland
- * E-mail:
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18
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Xue J, Zhu LP, Wei Q. IgG-Fc N-glycosylation at Asn297 and IgA O-glycosylation in the hinge region in health and disease. Glycoconj J 2013; 30:735-45. [PMID: 23783413 DOI: 10.1007/s10719-013-9481-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 05/16/2013] [Accepted: 05/16/2013] [Indexed: 01/21/2023]
Abstract
Immunoglobulins (Igs) are the major molecules secreted by B lymphocytes during an adaptive immune response. They are glycoproteins with distinctive glycosylation patterns, resulting in wide variations in the number, type and location of their oligosaccharides in each isotype and subclass. The sugars play specific structural roles, maintaining and modulating effector functions of Igs. Aberrant glycosylation might contribute to disease pathogenesis. This review will focus on the glycosylation of IgG and IgA because they have been studied more extensively than other immunoglobulins. Rheumatoid arthritis and IgA nephritis are used to describe the association of glycosylation aberration and disease pathogenesis.
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Affiliation(s)
- Jing Xue
- Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences (CAMS) and Comparative Medicine Center, Peking Union Medical College (PUMC), Key Laboratory of Human Disease Comparative Medicine, No 5 Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China
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19
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Primary breast cancer tumours contain high amounts of IgA1 immunoglobulin: an immunohistochemical analysis of a possible carrier of the tumour-associated Tn antigen. PLoS One 2013; 8:e61749. [PMID: 23637900 PMCID: PMC3630176 DOI: 10.1371/journal.pone.0061749] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 03/13/2013] [Indexed: 12/20/2022] Open
Abstract
The Tn antigen (GalNAc alpha-O-Ser/Thr) as defined by the binding of the lectin, helix pomatia agglutinin (HPA) or anti-Tn monoclonal antibodies, is known to be exposed in a majority of cancers, and it has also been shown to correlate positively with the metastatic capacity in breast carcinoma. The short O-glycan that forms the antigen is carried by a number of different proteins. One potential carrier of the Tn antigen is immunoglobulin A1 (IgA1), which we surprisingly found in tumour cells of the invasive parts of primary breast carcinoma. Conventional immunohistochemical analysis of paraffin-embedded sections from primary breast cancers showed IgA1 to be present in the cytoplasm and plasma membrane of 35 out of 36 individual primary tumours. The immunohistochemical staining of HPA and anti-Tn antibody (GOD3-2C4) did to some extent overlap with the presence of IgA1 in the tumours, but differences were seen in the percentage of stained cells and in the staining pattern in the different breast cancers analysed. Anti-Tn antibody and HPA were also shown to specifically bind to a number of possible constellations of the Tn antigen in the hinge region of IgA1. Both reagents could also detect the presence of Tn positive IgA in serum. On average 51% of the tumour cells in the individual breast cancer tumour sections showed staining for IgA1. The overall amount of staining in the invasive part of the tumour with the anti Tn antibody was 67%, and 93% with HPA. The intra-expression or uptake of IgA1 in breast cancer makes it a new potential carrier of the tumour associated and immunogenic Tn antigen.
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20
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Tamouza H, Chemouny JM, Raskova Kafkova L, Berthelot L, Flamant M, Demion M, Mesnard L, Paubelle E, Walker F, Julian BA, Tissandié E, Tiwari MK, Camara NOS, Vrtovsnik F, Benhamou M, Novak J, Monteiro RC, Moura IC. The IgA1 immune complex-mediated activation of the MAPK/ERK kinase pathway in mesangial cells is associated with glomerular damage in IgA nephropathy. Kidney Int 2012; 82:1284-96. [PMID: 22951891 DOI: 10.1038/ki.2012.192] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
IgA nephropathy (IgAN), the most common primary glomerulonephritis worldwide, has significant morbidity and mortality as 20-40% of patients progress to end-stage renal disease within 20 years of onset. In order to gain insight into the molecular mechanisms involved in the progression of IgAN, we systematically evaluated renal biopsies from such patients. This showed that the MAPK/ERK signaling pathway was activated in the mesangium of patients presenting with over 1 g/day proteinuria and elevated blood pressure, but absent in biopsy specimens of patients with IgAN and modest proteinuria (<1 g/day). ERK activation was not associated with elevated galactose-deficient IgA1 or IgG specific for galactose-deficient IgA1 in the serum. In human mesangial cells in vitro, ERK activation through mesangial IgA1 receptor (CD71) controlled pro-inflammatory cytokine secretion and was induced by large-molecular-mass IgA1-containing circulating immune complexes purified from patient sera. Moreover, IgA1-dependent ERK activation required renin-angiotensin system as its blockade was efficient in reducing proteinuria in those patients exhibiting substantial mesangial activation of ERK. Thus, ERK activation alters mesangial cell-podocyte crosstalk, leading to renal dysfunction in IgAN. Assessment of MAPK/ERK activation in diagnostic renal biopsies may predict the therapeutic efficacy of renin-angiotensin system blockers in IgAN.
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21
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Berthoux F, Suzuki H, Thibaudin L, Yanagawa H, Maillard N, Mariat C, Tomino Y, Julian BA, Novak J. Autoantibodies targeting galactose-deficient IgA1 associate with progression of IgA nephropathy. J Am Soc Nephrol 2012; 23:1579-87. [PMID: 22904352 DOI: 10.1681/asn.2012010053] [Citation(s) in RCA: 185] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Mesangial and circulating IgA1 with aberrantly glycosylated hinge region O-glycans characterize IgA nephropathy (IgAN). Unlike healthy individuals, some IgA1 is galactose deficient in patients with IgAN, leaving terminal N-acetylgalactosamine residues in the hinge region exposed. Circulating autoantibodies that recognize such galactose-deficient IgA1 as an autoantigen, or the levels of the autoantigen itself, may allow prediction of disease progression. Here, we analyzed serum samples obtained at diagnosis for autoantigen and autoantibodies from 97 patients with IgAN selected from our prospective cohort according to their absolute renal risk for progression to dialysis or death (0, very low; 1, low; 2, high; 3, very high). We also analyzed samples from controls comprising 30 healthy volunteers and 30 patients with non-IgAN disease. The mean follow-up was 13.8 years. We found that mean serum levels of total autoantigen, normalized IgG autoantibody, and total IgA autoantibody were significantly higher in patients than in the combined controls (all P≤0.01). Furthermore, increasing levels correlated with worse clinical outcomes. In Cox regression and Kaplan-Meier analyses, IgG autoantibody levels ≥1.33 predicted dialysis or death (both P≤0.01). In conclusion, these data suggest that serum levels of IgG and IgA autoantibodies strongly associate with the progression of IgAN nephropathy.
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Affiliation(s)
- Francois Berthoux
- Nephrology, Dialysis, and Renal Transplantation Department, University North Hospital, 42055 Saint-Etienne Cedex 2, France.
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22
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Abstract
AbstractAccording to the universal biological findings, cellular bodies are covered with an intense coating of glycans. Diversity of glycan chains, linked to lipids and proteins is due to isomeric and conformational modifications of various sugar residues, giving rise to unique carbohydrate structures with a wide range of sequences and anomeric configurations. Proteins and lipids, carrying specific sugar residues (like Galactose) with particular stereochemical properties (sequence, anomery and linkages) are involved in broad spectrums of biological processes, including intercellular and intracellular interactions, microbial adhesion and cellular signaling. By studying the role of specific seterochemical features of galactose (Gal), we have improved our understanding about the normal physiology and diseases in human bodies.
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23
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Inoue T, Sugiyama H, Kitagawa M, Takiue K, Morinaga H, Ogawa A, Kikumoto Y, Kitamura S, Maeshima Y, Makino H. Suppression of adiponectin by aberrantly glycosylated IgA1 in glomerular mesangial cells in vitro and in vivo. PLoS One 2012; 7:e33965. [PMID: 22457806 PMCID: PMC3311555 DOI: 10.1371/journal.pone.0033965] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 02/20/2012] [Indexed: 02/06/2023] Open
Abstract
The pathogenesis of IgA nephropathy (IgAN) may be associated with the mesangial deposition of aberrantly glycosylated IgA1. To identify mediators affected by aberrantly glycosylated IgA1 in cultured human mesangial cells (HMCs), we generated enzymatically modified desialylated and degalactosylated (deSial/deGal) IgA1. The state of deglycosylated IgA1 was confirmed by lectin binding to Helix aspersa (HAA) and Sambucus nigra (SNA). In the cytokine array analysis, 52 proteins were upregulated and 34 were downregulated in HMCs after stimulation with deSial/deGal IgA1. Among them, the secretion of adiponectin was suppressed in HMCs after stimulation with deSial/deGal IgA1. HMCs expressed mRNAs for adiponectin and its type 1 receptor, but not the type 2 receptor. Moreover, we revealed a downregulation of adiponectin expression in the glomeruli of renal biopsy specimens from patients with IgAN compared to those with lupus nephritis. We also demonstrated that aberrantly glycosylated IgA1 was deposited in the mesangium of patients with IgAN by dual staining of HAA and IgA. Moreover, the urinary HAA/SNA ratio of lectin binding was significantly higher in IgAN compared to other kidney diseases. Since adiponectin has anti-inflammatory effects, including the inhibition of adhesion molecules and cytokines, these data suggest that the local suppression of this adipokine by aberrantly glycosylated IgA1 could be involved in the regulation of glomerular inflammation and sclerosis in IgAN.
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Affiliation(s)
- Tatsuyuki Inoue
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
- Center for iPS Cell Research and Application, Kyoto University, Kyoto, Japan
| | - Hitoshi Sugiyama
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
- Center for Chronic Kidney Disease and Peritoneal Dialysis, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Masashi Kitagawa
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Keiichi Takiue
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Hiroshi Morinaga
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Ayu Ogawa
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Yoko Kikumoto
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Shinji Kitamura
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Yohei Maeshima
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Hirofumi Makino
- Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
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Novak J, Julian BA, Mestecky J, Renfrow MB. Glycosylation of IgA1 and pathogenesis of IgA nephropathy. Semin Immunopathol 2012; 34:365-82. [PMID: 22434325 DOI: 10.1007/s00281-012-0306-z] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Accepted: 03/02/2012] [Indexed: 12/18/2022]
Abstract
IgA nephropathy, described in 1968 as IgA-IgG immune-complex disease, is an autoimmune disease. Galactose-deficient IgA1 is recognized by unique autoantibodies, resulting in the formation of pathogenic immune complexes that ultimately induce glomerular injury. Thus, formation of the galactose-deficient IgA1-containing immune complexes is a critical factor in the pathogenesis of IgA nephropathy. Studies of molecular defects of IgA1 can define new biomarkers specific for IgA nephropathy that can be developed into clinical assays to aid in the diagnosis, assessment of prognosis, and monitoring of disease progression.
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Affiliation(s)
- Jan Novak
- University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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25
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Horynová M, Takahashi K, Hall S, Renfrow MB, Novak J, Raška M. Production of N-acetylgalactosaminyl-transferase 2 (GalNAc-T2) fused with secretory signal Igκ in insect cells. Protein Expr Purif 2012; 81:175-80. [PMID: 22033505 PMCID: PMC3637031 DOI: 10.1016/j.pep.2011.10.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 10/12/2011] [Accepted: 10/13/2011] [Indexed: 01/29/2023]
Abstract
The human UDP-N-acetyl-α-d-galactosamine:polypeptide N-acetylgalactosaminyl-transferase 2 (GalNAc-T2) is one of the key enzymes that initiate synthesis of hinge-region O-linked glycans of human immunoglobulin A1 (IgA1). We designed secreted soluble form of human GalNAc-T2 as a fusion protein containing mouse immunoglobulin light chain kappa secretory signal and expressed it using baculovirus and mammalian expression vectors. The recombinant protein was secreted by insect cells Sf9 and human HEK 293T cells in the culture medium. The protein was purified from the media using affinity Ni-NTA chromatography followed by stabilization of purified protein in 50mM Tris-HCl buffer at pH 7.4. Although the purity of recombinant GalNAc-T2 was comparable in both expression systems, the yield was higher in Sf9 insect expression system (2.5mg of GalNAc-T2 protein per 1L culture medium). The purified soluble recombinant GalNAc-T2 had an estimated molecular mass of 65.8kDa and its amino-acid sequence was confirmed by mass-spectrometric analysis. The enzymatic activity of Sf9-produced recombinant GalNAc-T2 was determined by the quantification of enzyme-mediated attachment of GalNAc to synthetic IgA1 hinge-region peptide as the acceptor and UDP-GalNAc as the donor. In conclusion, murine immunoglobulin kappa secretory signal was used for production of secreted enzymatically active GalNAc-T2 in insect baculovirus expression system.
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Affiliation(s)
- Milada Horynová
- Department of Immunology, Faculty of Medicine and Dentistry, Palacky University, Olomouc, Czech Republic
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Kazuo Takahashi
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Stacy Hall
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Matthew B. Renfrow
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Milan Raška
- Department of Immunology, Faculty of Medicine and Dentistry, Palacky University, Olomouc, Czech Republic
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
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Yanagihara T, Brown R, Hall S, Moldoveanu Z, Goepfert A, Tomana M, Julian BA, Mestecky J, Novak J. In vitro-generated immune complexes containing galactose-deficient IgA1 stimulate proliferation of mesangial cells. RESULTS IN IMMUNOLOGY 2012; 2:166-172. [PMID: 24052934 DOI: 10.1016/j.rinim.2012.08.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
IgA nephropathy (IgAN) patients have elevated serum levels of immune complexes consisting of IgA1 with galactose-deficient hinge-region O-glycans (Gd-IgA1) and anti-glycan IgG. These immune complexes deposit in the kidney and activate mesangial cells. To confirm that the activity of these immune complexes depends on the interaction of Gd-IgA1 with anti-glycan IgG, we generated in vitro analogous immune complexes using Gd-IgA1 myeloma protein and anti-glycan IgG from cord blood of healthy women. The Gd-IgA1 and anti-glycan IgG from cord-blood serum formed IgA1-IgG immune complexes that resembled those in sera of patients with IgAN. Furthermore, the ability to activate cellular proliferation was dependent on a heat-sensitive serum factor. In summary, we developed a new protocol for in-vitro formation of IgA1-IgG immune complexes, thus providing a new tool for studies of the pathogenesis of IgAN.
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Affiliation(s)
- Takeshi Yanagihara
- Department of Microbiology, University of Alabama, Birmingham, AL, USA ; Department of Pediatrics, Nippon Medical School, Tokyo, Japan
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27
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Carlsson MC, Bakoush O, Tengroth L, Kilsgård O, Malmström J, Hellmark T, Segelmark M, Leffler H. Galectin-8 in IgA nephritis: decreased binding of IgA by galectin-8 affinity chromatography and associated increased binding in non-IgA serum glycoproteins. J Clin Immunol 2011; 32:246-55. [PMID: 22173878 PMCID: PMC3305883 DOI: 10.1007/s10875-011-9618-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 11/11/2011] [Indexed: 12/18/2022]
Abstract
Background Immunoglobulin A nephritis (IgAN) is the most common primary glomerulonephritis worldwide. It is caused by accumulation of IgA1-containing immune complexes in the kidney resulting in renal failure, which is thought to be due to altered glycosylation of IgA with a decrease of 2–3-sialylated galactosides (NeuAcα2-3Gal). Purpose The purpose of this study was to analyze whether altered glycosylation of IgA would lead to an altered binding to galectin-8, an endogenous lectin with strong affinity for 2–3-sialylated galactosides. Galectins are a family of β-galactoside-binding proteins; by binding various glycoproteins, they play important roles in the regulation of cellular functions in inflammation and immunity. Hence, an altered binding of IgA to galectin-8 could lead to pathologic immune functions, such as glomerulonephritis. Methods Affinity chromatography of serum glycoproteins on the human sialogalactoside-binding lectin galectin-8N permitted quantitation of bound and unbound fractions, including IgA. Results Analysis of ∼100 IgA nephritis sera showed that the galectin-8N unbound fraction of IgA increased compared to ∼100 controls, consistent with the known loss of galactosylation. A subgroup of ∼15% of the IgAN patients had a ratio of galectin-8 bound/unbound IgA <0.09, not found for any of the controls. Unexpectedly, the galectin-8N-binding fraction of serum glycoproteins other than IgA increased in the sera of IgAN patients but not in controls, suggesting a previously unrecognized change in this disease. Conclusion This is the first study that relates a galectin, an endogenous lectin family, to IgA nephritis and thus should stimulate new avenues of research into the pathophysiology of the disease. Electronic supplementary material The online version of this article (doi:10.1007/s10875-011-9618-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Michael C. Carlsson
- Section MIG (Microbiology, Immunology, Glycobiology), Department of Laboratory Medicine, Lund University, Sölvegatan 23, 223 62 Lund, Sweden
| | - Omran Bakoush
- Department of Nephrology, Lund University Hospital, Lund, Sweden
| | - Lotta Tengroth
- Section MIG (Microbiology, Immunology, Glycobiology), Department of Laboratory Medicine, Lund University, Sölvegatan 23, 223 62 Lund, Sweden
| | - Ola Kilsgård
- Department of Immunotechnology, Lund University, Lund, Sweden
| | - Johan Malmström
- Department of Immunotechnology, Lund University, Lund, Sweden
| | - Thomas Hellmark
- Department of Nephrology, Lund University Hospital, Lund, Sweden
| | - Mårten Segelmark
- Department of Nephrology, Lund University Hospital, Lund, Sweden
- Department of Medicine and Health, Linköping University, Linköping, Sweden
| | - Hakon Leffler
- Section MIG (Microbiology, Immunology, Glycobiology), Department of Laboratory Medicine, Lund University, Sölvegatan 23, 223 62 Lund, Sweden
- Department of Clinical Immunology and Transfusion Medicine, Skåne University Hospital SUS., Lund, Sweden
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28
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Neto LGDN, Pinto LDS, Bastos RM, Evaristo FFV, de Vasconcelos MA, Carneiro VA, Arruda FVS, Porto ALF, Leal RB, Júnior VADS, Cavada BS, Teixeira EH. Effect of the lectin of Bauhinia variegata and its recombinant isoform on surgically induced skin wounds in a murine model. Molecules 2011; 16:9298-315. [PMID: 22064270 PMCID: PMC6264313 DOI: 10.3390/molecules16119298] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 10/20/2011] [Accepted: 10/27/2011] [Indexed: 11/16/2022] Open
Abstract
Lectins are a structurally heterogeneous group of highly specific carbohydrate-binding proteins. Due to their great biotechnological potential, lectins are widely used in biomedical research. The purpose of the present study was to evaluate the healing potential of the lectin of Bauhinia variegata (nBVL) and its recombinant isoform (rBVL-1). Following surgical creation of dorsal skin wounds, seven groups of mice were submitted to topical treatment for 12 days with lectin, D-galactose, BSA and saline. The animals were anesthetized and euthanized on POD 2, 7 and 12 in order to evaluate the healing potential of each treatment. The parameters considered included wound size, contraction rate, epithelialization rate and histopathological findings. Wound closure was fastest in animals treated with rBVL-1 (POD 7). nBVL was more effective than the controls. All skin layers were reconstructed and keratin deposition increased. Our findings indicate that the lectin of Bauhinia variegata possesses pro-healing properties and may be employed in the treatment of acute skin wounds.
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Affiliation(s)
- Luiz Gonzaga do Nascimento Neto
- Integrated Laboratory of Biomolecules (LIBS), School of Medicine of the Federal University of Ceará, Sobral, Ceará 62042-280, Brazil; E-Mails: (L.G.N.N.); (R.M.B.); (F.F.V.E.); (V.A.C.); (F.V.S.A.)
| | - Luciano da Silva Pinto
- Center for Technological Development (CDTec), Unidad of Biotecnology, Federal University of Pelotas, Pelotas, Rio Grande do Sul, 96010-900, Brazil; E-Mail: (L.d.S.P.)
| | - Rafaela Mesquita Bastos
- Integrated Laboratory of Biomolecules (LIBS), School of Medicine of the Federal University of Ceará, Sobral, Ceará 62042-280, Brazil; E-Mails: (L.G.N.N.); (R.M.B.); (F.F.V.E.); (V.A.C.); (F.V.S.A.)
| | - Francisco Flávio Vasconcelos Evaristo
- Integrated Laboratory of Biomolecules (LIBS), School of Medicine of the Federal University of Ceará, Sobral, Ceará 62042-280, Brazil; E-Mails: (L.G.N.N.); (R.M.B.); (F.F.V.E.); (V.A.C.); (F.V.S.A.)
| | - Mayron Alves de Vasconcelos
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Ceará 60451-970, Brazil; E-Mails: (M.A.V.); (B.S.C.)
| | - Victor Alves Carneiro
- Integrated Laboratory of Biomolecules (LIBS), School of Medicine of the Federal University of Ceará, Sobral, Ceará 62042-280, Brazil; E-Mails: (L.G.N.N.); (R.M.B.); (F.F.V.E.); (V.A.C.); (F.V.S.A.)
| | - Francisco Vassiliepe Sousa Arruda
- Integrated Laboratory of Biomolecules (LIBS), School of Medicine of the Federal University of Ceará, Sobral, Ceará 62042-280, Brazil; E-Mails: (L.G.N.N.); (R.M.B.); (F.F.V.E.); (V.A.C.); (F.V.S.A.)
| | - Ana Lúcia Figueiredo Porto
- Department of Animal Morphology and Physiology, Federal Rural University of Pernambuco, Recife, Pernambuco 52171-900, Brazil; E-Mails: (A.L.F.P.); (V.A.d.S.J.)
| | - Rodrigo Bainy Leal
- Department of Biochemistry, CBB, Federal University of Santa Catarina, Santa Catarina 88040-970, Brazil; E-Mail: (B.B.L.)
| | - Valdemiro Amaro da Silva Júnior
- Department of Animal Morphology and Physiology, Federal Rural University of Pernambuco, Recife, Pernambuco 52171-900, Brazil; E-Mails: (A.L.F.P.); (V.A.d.S.J.)
| | - Benildo Sousa Cavada
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Ceará 60451-970, Brazil; E-Mails: (M.A.V.); (B.S.C.)
| | - Edson Holanda Teixeira
- Integrated Laboratory of Biomolecules (LIBS), School of Medicine of the Federal University of Ceará, Sobral, Ceará 62042-280, Brazil; E-Mails: (L.G.N.N.); (R.M.B.); (F.F.V.E.); (V.A.C.); (F.V.S.A.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +55-88-3611-8000; Fax: +55-88-3611-2202
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Suzuki H, Kiryluk K, Novak J, Moldoveanu Z, Herr AB, Renfrow MB, Wyatt RJ, Scolari F, Mestecky J, Gharavi AG, Julian BA. The pathophysiology of IgA nephropathy. J Am Soc Nephrol 2011; 22:1795-803. [PMID: 21949093 DOI: 10.1681/asn.2011050464] [Citation(s) in RCA: 525] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Here we discuss recent advances in understanding the biochemical, immunologic, and genetic pathogenesis of IgA nephropathy, the most common primary glomerulonephritis. Current data indicate that at least four processes contribute to development of IgA nephropathy. Patients with IgA nephropathy often have a genetically determined increase in circulating levels of IgA1 with galactose-deficient O-glycans in the hinge-region (Hit 1). This glycosylation aberrancy is, however, not sufficient to induce renal injury. Synthesis and binding of antibodies directed against galactose-deficient IgA1 are required for formation of immune complexes that accumulate in the glomerular mesangium (Hits 2 and 3). These immune complexes activate mesangial cells, inducing proliferation and secretion of extracellular matrix, cytokines, and chemokines, which result in renal injury (Hit 4). Recent genome-wide association studies identify five distinct susceptibility loci--in the MHC on chromosome 6p21, the complement factor H locus on chromosome 1q32, and in a cluster of genes on chromosome 22q22--that potentially influence these processes and contain candidate mediators of disease. The significant variation in prevalence of risk alleles among different populations may also explain some of the sizable geographic variation in disease prevalence. Elucidation of the pathogenesis of IgA nephropathy provides an opportunity to develop disease-specific therapies.
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Affiliation(s)
- Hitoshi Suzuki
- Department of Internal Medicine, Division of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
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Maixnerova D, Bauerova L, Skibova J, Rysava R, Reiterova J, Merta M, Honsova E, Tesar V. The retrospective analysis of 343 Czech patients with IgA nephropathy--one centre experience. Nephrol Dial Transplant 2011; 27:1492-8. [PMID: 21891776 DOI: 10.1093/ndt/gfr482] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND The aim of our study was to retrospectively analyse the clinical data and the histological findings of 343 patients (pts) followed up with IgA nephropathy (IgAN) in our department of nephrology. We have assessed the main demographic, clinical and histological data, and the medical treatment of IgAN pts. METHODS Multivariate analysis was used to evaluate the effect of different variables on ≥50% increase of plasma creatinine level from baseline during a median follow-up of 4 years. RESULTS In our group of IgAN pts, the male gender (68%) predominated over female gender (32%). At the time of renal biopsy, the median age of IgAN pts was 32.3 (18-90) years, the median level of serum creatinine was 119 μmol/L and the median level of proteinuria was 1.8 g/day. Most of the pts were found to have arterial hypertension (56.7%). The majority of the pts with arterial hypertension were treated with inhibitors of angiotensin-converting enzyme (80.4%) and the remaining pts (42.6%) were treated with angiotensin II receptor blockers. Fifty per cent of the pts (170 pts) were treated of corticosteroids, 21% of the pts (71 pts) used a combined immunosuppressive treatment of corticosteroids and cyclophosphamide, 8% of the pts (27 pts) took azathioprine, 1.5% of the pts (5 pts) took cyclosporine and 1.5% of the pts (5 pts) were given mycophenolate mofetil. Hypertension at presentation, fibrointimal proliferation of arterial vessels, interstitial fibrosis and interstitial inflammation were shown to be associated with ≥50% increase of plasma creatinine level from baseline in univariate analysis (P<0.05 for hypertension and fibrointimal proliferation; P<0.01 for interstitial fibrosis and inflammation). Using stepwise logistic regression presenting proteinuria>2 g/day [odds ratio (OR)=2.24, P<0.01], tubular atrophy (OR=4.97, P<0.01) and damage of tubular epithelium (OR=1.78, P<0.05) were found as risk factors for ≥50% increase of plasma creatinine level from baseline. CONCLUSION Our retrospective analysis found valuable information not only about the clinical, laboratory and histological findings in IgAN pts but also information about the risk factors influencing the progression of renal insufficiency.
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Affiliation(s)
- Dita Maixnerova
- Department of Nephrology, 1st Medical Faculty, Charles University, Prague, Czech Republic.
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