1
|
Matsumoto Y, Aryal RP, Heimburg-Molinaro J, Park SS, Wever WJ, Lehoux S, Stavenhagen K, van Wijk JAE, Van Die I, Chapman AB, Chaikof EL, Cummings RD. Identification and characterization of circulating immune complexes in IgA nephropathy. SCIENCE ADVANCES 2022; 8:eabm8783. [PMID: 36306365 PMCID: PMC9616497 DOI: 10.1126/sciadv.abm8783] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 09/12/2022] [Indexed: 05/14/2023]
Abstract
The underlying pathology of immunoglobulin A (IgA) nephropathy (IgAN), the most common glomerulonephritis worldwide, is driven by the deposition of immune complexes containing galactose-deficient IgA1 [Tn(+)IgA1] in the glomerular mesangium. Here, we report that novel anti-Tn circulating immune complexes (anti-Tn CICs) contain predominantly IgM, representing large macromolecular complexes of ~1.2 megadaltons to several megadalton sizes together with Tn(+)IgA1 and some IgG. These complexes are significantly elevated in sera of patients with IgAN, which contains higher levels of complement C3, compared to healthy individuals. Anti-Tn CICs are bioactive and induce specific proliferation of human renal mesangial cells. We found that these anti-Tn CICs can be dissociated with small glycomimetic compounds, which mimic the Tn antigen of Tn(+)IgA1, releasing IgA1 from anti-Tn CICs. This glycomimetic compound can also significantly inhibit the proliferative activity of anti-Tn CICs of patients with IgAN. These findings could enhance both the diagnosis of IgAN and its treatment, as specific drug treatments are now unavailable.
Collapse
Affiliation(s)
- Yasuyuki Matsumoto
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Rajindra P. Aryal
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Jamie Heimburg-Molinaro
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Simon S. Park
- Department of Surgery, Center for Drug Discovery and Translational Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Wyss Institute of Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Walter J. Wever
- Department of Surgery, Center for Drug Discovery and Translational Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Wyss Institute of Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Sylvain Lehoux
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Kathrin Stavenhagen
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Joanna A. E. van Wijk
- Department of Pediatric Nephrology, Amsterdam University Medical Centre, location VUmc, Amsterdam, Netherlands
| | - Irma Van Die
- Department of Molecular Cell Biology and Immunology, Amsterdam University Medical Centre, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Arlene B. Chapman
- Department of Medicine, Section of Nephrology, University of Chicago School of Medicine, Chicago, IL, USA
| | - Elliot L. Chaikof
- Department of Surgery, Center for Drug Discovery and Translational Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Wyss Institute of Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Richard D. Cummings
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
2
|
Ebefors K, Bergwall L, Nyström J. The Glomerulus According to the Mesangium. Front Med (Lausanne) 2022; 8:740527. [PMID: 35155460 PMCID: PMC8825785 DOI: 10.3389/fmed.2021.740527] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 12/27/2021] [Indexed: 02/06/2023] Open
Abstract
The glomerulus is the functional unit for filtration of blood and formation of primary urine. This intricate structure is composed of the endothelium with its glycocalyx facing the blood, the glomerular basement membrane and the podocytes facing the urinary space of Bowman's capsule. The mesangial cells are the central hub connecting and supporting all these structures. The components as a unit ensure a high permselectivity hindering large plasma proteins from passing into the urine while readily filtering water and small solutes. There has been a long-standing interest and discussion regarding the functional contribution of the different cellular components but the mesangial cells have been somewhat overlooked in this context. The mesangium is situated in close proximity to all other cellular components of the glomerulus and should be considered important in pathophysiological events leading to glomerular disease. This review will highlight the role of the mesangium in both glomerular function and intra-glomerular crosstalk. It also aims to explain the role of the mesangium as a central component involved in disease onset and progression as well as signaling to maintain the functions of other glomerular cells to uphold permselectivity and glomerular health.
Collapse
Affiliation(s)
- Kerstin Ebefors
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lovisa Bergwall
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Jenny Nyström
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
3
|
Pathogenesis of IgA Nephropathy: Current Understanding and Implications for Development of Disease-Specific Treatment. J Clin Med 2021; 10:jcm10194501. [PMID: 34640530 PMCID: PMC8509647 DOI: 10.3390/jcm10194501] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 09/22/2021] [Indexed: 12/20/2022] Open
Abstract
IgA nephropathy, initially described in 1968 as a kidney disease with glomerular “intercapillary deposits of IgA-IgG”, has no disease-specific treatment and is a common cause of kidney failure. Clinical observations and laboratory analyses suggest that IgA nephropathy is an autoimmune disease wherein the kidneys are damaged as innocent bystanders due to deposition of IgA1-IgG immune complexes from the circulation. A multi-hit hypothesis for the pathogenesis of IgA nephropathy describes four sequential steps in disease development. Specifically, patients with IgA nephropathy have elevated circulating levels of IgA1 with some O-glycans deficient in galactose (galactose-deficient IgA1) and these IgA1 glycoforms are recognized as autoantigens by unique IgG autoantibodies, resulting in formation of circulating immune complexes, some of which deposit in glomeruli and activate mesangial cells to induce kidney injury. This proposed mechanism is supported by observations that (i) glomerular immunodeposits in patients with IgA nephropathy are enriched for galactose-deficient IgA1 glycoforms and the corresponding IgG autoantibodies; (ii) circulatory levels of galactose-deficient IgA1 and IgG autoantibodies predict disease progression; and (iii) pathogenic potential of galactose-deficient IgA1 and IgG autoantibodies was demonstrated in vivo. Thus, a better understanding of the structure–function of these immunoglobulins as autoantibodies and autoantigens will enable development of disease-specific treatments.
Collapse
|
4
|
Abstract
IgA nephropathy (IgAN) is the most common type of glomerulonephritis in Asia and the Western world. In most patients, it follows an asymptomatic to oligosymptomatic course and GFR loss, if any, is slow. The mainstay of therapy therefore is optimized supportive care, i.e., measures that lower blood pressure, reduce proteinuria, minimize lifestyle risk factors, and otherwise help to reduce non-specific insults to the kidneys. The value of immunosuppression has become controversial and if at all, systemic high-dose corticosteroid therapy should be considered for a few months taking into account patient characteristics that would caution against or preclude such therapy. In addition, adverse events related to corticosteroid therapy markedly increase as GFR declines. Beyond corticosteroids, there is little evidence that any additional immunosuppression is helpful, with the exception of mycophenolate mofetil in patients of Asian descent. A considerable number of clinical trials ranging from enteric coated budesonide to blockade of B-cell function to complement inhibitors are currently ongoing and will hopefully allow a more targeted therapy of high-risk patients with progressive IgAN in the future.
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Xu B, Zhu L, Wang Q, Zhao Y, Jia M, Shi S, Liu L, Lv J, Lai W, Ji J, Zhang H. Mass spectrometry-based screening identifies circulating immunoglobulinA-α1-microglobulin complex as potential biomarker in immunoglobulin A nephropathy. Nephrol Dial Transplant 2021; 36:782-792. [PMID: 33351144 DOI: 10.1093/ndt/gfaa352] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Immunoglobulin A nephropathy (IgAN) is characterized by predominant IgA deposition in the glomerular mesangium. Previous studies have proved that renal-deposited IgA in IgAN came from circulating IgA1-containing complexes (CICs). METHODS To explore the composition of CICs in IgAN, we isolated CICs from IgAN patients and healthy controls and then quantitatively analyzed them by mass spectrometry. Meanwhile, the isolated CICs were used to treat human mesangial cells to monitor mesangial cell injury. Using the protein content and injury effects, the key constituent in CICs was identified. Then the circulating levels of identified key constituent-IgA complex were detected in an independent population by an in-house-developed enzyme-linked immunosorbent assay. RESULTS By comparing the proteins of CICs between IgAN patients and controls, we found that 14 proteins showed significantly different levels. Among them, α1-microglobulin content in CICs was associated with not only in vitro mesangial cell proliferation and monocyte chemoattractant protein 1 secretion, but also in vivo estimated glomerular filtration rate (eGFR) levels and tubulointerstitial lesions in IgAN patients. Moreover, we found α1-microglobulin was prone to bind aberrant glycosylated IgA1. Additionally, elevated circulating IgA-α1-microglobulin complex levels were detected in an independent IgAN population and IgA-α1-microglobulin complex levels were correlated with hypertension, eGFR levels and Oxford T- scores in these IgAN patients. CONCLUSIONS Our results suggest that the IgA-α1-microglobulin complex is an important constituent in CICs and that circulating IgA-α1-microglobulin complex detection might serve as a potential noninvasive biomarker detection method for IgAN.
Collapse
Affiliation(s)
- Boyang Xu
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, China, and Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease (Peking University), National Health Commission, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education, Beijing, China.,Research Unit of Diagnosis and Treatment of Immune-Mediated Kidney Disease, Chinese Academy of Medical Sciences, Beijing, China
| | - Li Zhu
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, China, and Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease (Peking University), National Health Commission, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education, Beijing, China.,Research Unit of Diagnosis and Treatment of Immune-Mediated Kidney Disease, Chinese Academy of Medical Sciences, Beijing, China
| | - Qingsong Wang
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, China
| | - Yanfeng Zhao
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, China, and Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease (Peking University), National Health Commission, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education, Beijing, China.,Research Unit of Diagnosis and Treatment of Immune-Mediated Kidney Disease, Chinese Academy of Medical Sciences, Beijing, China
| | - Meng Jia
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, China, and Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease (Peking University), National Health Commission, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education, Beijing, China.,Research Unit of Diagnosis and Treatment of Immune-Mediated Kidney Disease, Chinese Academy of Medical Sciences, Beijing, China
| | - Sufang Shi
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, China, and Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease (Peking University), National Health Commission, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education, Beijing, China.,Research Unit of Diagnosis and Treatment of Immune-Mediated Kidney Disease, Chinese Academy of Medical Sciences, Beijing, China
| | - Lijun Liu
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, China, and Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease (Peking University), National Health Commission, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education, Beijing, China.,Research Unit of Diagnosis and Treatment of Immune-Mediated Kidney Disease, Chinese Academy of Medical Sciences, Beijing, China
| | - Jicheng Lv
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, China, and Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease (Peking University), National Health Commission, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education, Beijing, China.,Research Unit of Diagnosis and Treatment of Immune-Mediated Kidney Disease, Chinese Academy of Medical Sciences, Beijing, China
| | - Wenjia Lai
- Chinese Academy of Sciences Key Laboratory of Standardization and Measurement for Nanotechnology, Chinese Academy of Sciences Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, China
| | - Jianguo Ji
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, China
| | - Hong Zhang
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, China, and Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease (Peking University), National Health Commission, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education, Beijing, China.,Research Unit of Diagnosis and Treatment of Immune-Mediated Kidney Disease, Chinese Academy of Medical Sciences, Beijing, China
| |
Collapse
|
7
|
Moldoveanu Z, Suzuki H, Reily C, Satake K, Novak L, Xu N, Huang ZQ, Knoppova B, Khan A, Hall S, Yanagawa H, Brown R, Winstead CJ, O'Quinn DB, Weinmann A, Gharavi AG, Kiryluk K, Julian BA, Weaver CT, Suzuki Y, Novak J. Experimental evidence of pathogenic role of IgG autoantibodies in IgA nephropathy. J Autoimmun 2021; 118:102593. [PMID: 33508637 DOI: 10.1016/j.jaut.2021.102593] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 12/30/2020] [Accepted: 12/31/2020] [Indexed: 01/13/2023]
Abstract
BACKGROUND IgA nephropathy is thought to be an autoimmune disease wherein galactose-deficient IgA1 (Gd-IgA1) is recognized by IgG autoantibodies, resulting in formation and renal accumulation of nephritogenic immune complexes. Although this hypothesis is supported by recent findings that, in renal immunodeposits of IgA nephropathy patients, IgG is enriched for Gd-IgA1-specific autoantibodies, experimental proof is still lacking. METHODS IgG isolated from sera of IgA nephropathy patients or produced as a recombinant IgG (rIgG) was mixed with human Gd-IgA1 to form immune complexes. IgG from healthy individuals served as a control. Nude and SCID mice were injected with human IgG and Gd-IgA1, in immune complexes or individually, and their presence in kidneys was ascertained by immunofluorescence. Pathologic changes in the glomeruli were evaluated by quantitative morphometry and exploratory transcriptomic profiling was performed by RNA-Seq. RESULTS Immunodeficient mice injected with Gd-IgA1 mixed with IgG autoantibodies from patients with IgA nephropathy, but not Gd-IgA1 mixed with IgG from healthy individuals, displayed IgA, IgG, and mouse complement C3 glomerular deposits and mesangioproliferative glomerular injury with hematuria and proteinuria. Un-complexed Gd-IgA1 or IgG did not induce pathological changes. Moreover, Gd-IgA1-rIgG immune complexes injected into immunodeficient mice induced histopathological changes characteristic of human disease. Exploratory transcriptome profiling of mouse kidney tissues indicated that these immune complexes altered gene expression of multiple pathways, in concordance with the changes observed in kidney biopsies of patients with IgA nephropathy. CONCLUSIONS This study provides the first in vivo evidence for a pathogenic role of IgG autoantibodies specific for Gd-IgA1 in the pathogenesis of IgA nephropathy.
Collapse
Affiliation(s)
| | - Hitoshi Suzuki
- University of Alabama at Birmingham, Birmingham, AL, USA; Department of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Colin Reily
- University of Alabama at Birmingham, Birmingham, AL, USA
| | - Kenji Satake
- Department of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Lea Novak
- University of Alabama at Birmingham, Birmingham, AL, USA
| | - Nuo Xu
- University of Alabama at Birmingham, Birmingham, AL, USA
| | | | | | - Atlas Khan
- Department of Medicine, Division of Nephrology, College of Physicians & Surgeons, Columbia University, New York, NY, USA
| | - Stacy Hall
- University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hiroyuki Yanagawa
- Department of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Rhubell Brown
- University of Alabama at Birmingham, Birmingham, AL, USA
| | | | | | - Amy Weinmann
- University of Alabama at Birmingham, Birmingham, AL, USA
| | - Ali G Gharavi
- Department of Medicine, Division of Nephrology, College of Physicians & Surgeons, Columbia University, New York, NY, USA
| | - Krzysztof Kiryluk
- Department of Medicine, Division of Nephrology, College of Physicians & Surgeons, Columbia University, New York, NY, USA
| | - Bruce A Julian
- University of Alabama at Birmingham, Birmingham, AL, USA
| | - Casey T Weaver
- University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yusuke Suzuki
- Department of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Jan Novak
- University of Alabama at Birmingham, Birmingham, AL, USA.
| |
Collapse
|
8
|
Wu MY, Chen CS, Yiang GT, Cheng PW, Chen YL, Chiu HC, Liu KH, Lee WC, Li CJ. The Emerging Role of Pathogenesis of IgA Nephropathy. J Clin Med 2018; 7:jcm7080225. [PMID: 30127305 PMCID: PMC6112037 DOI: 10.3390/jcm7080225] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 08/12/2018] [Accepted: 08/16/2018] [Indexed: 12/20/2022] Open
Abstract
IgA nephropathy is an autoimmune disease induced by fthe ormation of galactose-deficient IgA1 and anti-glycans autoantibody. A multi-hit hypothesis was promoted to explain full expression of IgA nephropathy. The deposition of immune complex resulted in activation of the complement, increasing oxidative stress, promoting inflammatory cascade, and inducing cell apoptosis via mesangio-podocytic-tubular crosstalk. The interlinked signaling pathways of immune-complex-mediated inflammation can offer a novel target for therapeutic approaches. Treatments of IgA nephropathy are also summarized in our review article. In this article, we provide an overview of the recent basic and clinical studies in cell molecular regulation of IgAN for further treatment interventions.
Collapse
Affiliation(s)
- Meng-Yu Wu
- Department of Emergency Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan.
- Department of Emergency Medicine, School of Medicine, Tzu Chi University, Hualien 970, Taiwan.
| | - Chien-Sheng Chen
- Department of Emergency Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan.
- Department of Emergency Medicine, School of Medicine, Tzu Chi University, Hualien 970, Taiwan.
| | - Giou-Teng Yiang
- Department of Emergency Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan.
- Department of Emergency Medicine, School of Medicine, Tzu Chi University, Hualien 970, Taiwan.
| | - Pei-Wen Cheng
- Yuh-Ing Junior College of Health Care & Management, Kaohsiung 807, Taiwan.
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan.
| | - Yu-Long Chen
- Department of Emergency Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan.
- Department of Emergency Medicine, School of Medicine, Tzu Chi University, Hualien 970, Taiwan.
| | - Hsiao-Chen Chiu
- Department of Obstetrics and Gynecology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan.
- Department of Obstetrics and Gynecology, School of Medicine, Tzu Chi University, Hualien 970, Taiwan.
| | - Kuan-Hung Liu
- Division of Nephrology, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine National Cheng Kung University, Tainan 704, Taiwan.
| | - Wen-Chin Lee
- Division of Nephrology, Department of Internal Medicine, Chang Bing Show Chwan Memorial Hospital, Changhua 505, Taiwan.
| | - Chia-Jung Li
- Research Assistant Center, Show Chwan Memorial Hospital, Changhua 500, Taiwan.
| |
Collapse
|
9
|
Nguyen C, König K, Tam FWK, Hopfer H, Molyneux K, Binet FI, Kim MJ. Higher serum galactose-deficient immunoglobulin A1 concentration is associated with stronger mesangial cellular inflammatory response and more severe histologic findings in immunoglobulin A nephropathy. Clin Kidney J 2018; 12:232-238. [PMID: 30976401 PMCID: PMC6452211 DOI: 10.1093/ckj/sfy068] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Indexed: 01/01/2023] Open
Abstract
Background Galactose-deficient immunoglobulin A1 (Gd-IgA1) is known to play a key role in the pathogenesis of IgA nephropathy (IgAN). We aimed to evaluate whether serum Gd-IgA1 is associated with in vitro activation of mesangial cells in individual patients and how this affects the clinical and histologic parameters. Methods Serum samples and clinical and histologic data were collected in the University Hospital Basel and Hammersmith Hospital, London. Serum levels of IgA1 and Gd-IgA1 were measured by enzyme-linked immunosorbent assay (ELISA) and lectin-binding assay using lectin Helix aspersa (HA). Primary human mesangial cells were stimulated with IgA1 isolated from serum from individual patients and the concentrations of monocyte chemoattractant protein-1 and interleukin-6 were measured in cell culture supernatant by ELISA. Results Thirty-three patients were enrolled. A significant correlation was observed between serum Gd-IgA1 levels and the concentration of MCP-1 in the culture supernatant in individual patients (Spearman r = 0.5969, P = 0.0002). There was no significant correlation between serum Gd-IgA1 levels and proteinuria or estimated glomerular filtration rate at diagnosis. However, the serum Gd-IgA1 level was significantly higher in patients with segmental glomerulosclerosis (S0 versus S1, P = 0.0245) and tubular atrophy/interstitial fibrosis (T0 versus T1 and T2, P = 0.0336; T0 versus T2, P = 0.0225). Conclusions Higher serum Gd-IgA1 concentration is associated with stronger mesangial cell inflammatory response with production of a greater amount of MCP-1 in vitro. This in turn is associated with severe histologic changes. The disease progression with worse renal outcome in patients with higher serum Gd-IgA1 may be therefore mediated by more pronounced mesangial cell inflammatory response leading to more severe histologic changes.
Collapse
Affiliation(s)
- Celine Nguyen
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Katrin König
- Clinic for Transplantation Immunology and Nephrology, University Hospital Basel, Basel, Switzerland
| | - Frederick W K Tam
- Renal and Transplant Centre, Renal and Vascular Inflammation Section, Department of Medicine, Hammersmith Hospital, Imperial College London, London, UK
| | - Helmut Hopfer
- Institute for Pathology, University Hospital Basel, Basel, Switzerland
| | - Karen Molyneux
- Department of Infection, Immunity & Inflammation, University of Leicester, Leicester, UK
| | - Francoise-Isabelle Binet
- Clinic for Nephrology and Transplantation Medicine, Kantonsspital St. Gallen, St. Gallen, Switzerland
| | - Min Jeong Kim
- Department of Biomedicine, University of Basel, Basel, Switzerland.,Clinic for Nephrology and Transplantation Medicine, Kantonsspital St. Gallen, St. Gallen, Switzerland
| |
Collapse
|
10
|
Heineke MH, Ballering AV, Jamin A, Ben Mkaddem S, Monteiro RC, Van Egmond M. New insights in the pathogenesis of immunoglobulin A vasculitis (Henoch-Schönlein purpura). Autoimmun Rev 2017; 16:1246-1253. [PMID: 29037908 DOI: 10.1016/j.autrev.2017.10.009] [Citation(s) in RCA: 198] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 08/29/2017] [Indexed: 12/16/2022]
Abstract
Immunoglobulin A vasculitis (IgAV), also referred to as Henoch-Schönlein purpura, is the most common form of childhood vasculitis. The pathogenesis of IgAV is still largely unknown. The disease is characterized by IgA1-immune deposits, complement factors and neutrophil infiltration, which is accompanied with vascular inflammation. Incidence of IgAV is twice as high during fall and winter, suggesting an environmental trigger associated to climate. Symptoms can resolve without intervention, but some patients develop glomerulonephritis with features similar to IgA nephropathy that include hematuria, proteinuria and IgA deposition in the glomerulus. Ultimately, this can lead to end-stage renal disease. In IgA nephropathy immune complexes containing galactose-deficient (Gd-)IgA1 are found and thought to play a role in pathogenesis. Although Gd-IgA1 complexes are also present in patients with IgAV with nephritis, their role in IgAV is disputed. Alternatively, it has been proposed that in IgAV IgA1 antibodies are generated against endothelial cells. We anticipate that such IgA complexes can activate neutrophils via the IgA Fc receptor FcαRI (CD89), thereby inducing neutrophil migration and activation, which ultimately causes tissue damage in IgAV. In this Review, we discuss the putative role of IgA, IgA receptors, neutrophils and other factors such as infections, genetics and the complement system in the pathogenesis of IgA vasculitis.
Collapse
Affiliation(s)
- Marieke H Heineke
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, De Boelelaan 1109, 1081 HZ Amsterdam, The Netherlands; Amsterdam Infection & Immunity Institute, Amsterdam, The Netherlands
| | - Aranka V Ballering
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, De Boelelaan 1109, 1081 HZ Amsterdam, The Netherlands; Amsterdam Infection & Immunity Institute, Amsterdam, The Netherlands
| | - Agnès Jamin
- National French Institute of Health and Medical Research (INSERM) U1149, Centre de Recherche Sur l'Inflammation, 16 Rue Henri Huchard, Paris 75018, France; National French Center of Scientific Research (CNRS) ERL8252, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Faculté de Médecine, Site Xavier Bichat, 16 Rue Henri Huchard, Paris 75018, France; Laboratory of Inflamex Excellency, Faculty of Medicine, Xavier Bichat Site, Paris, France
| | - Sanae Ben Mkaddem
- National French Institute of Health and Medical Research (INSERM) U1149, Centre de Recherche Sur l'Inflammation, 16 Rue Henri Huchard, Paris 75018, France; National French Center of Scientific Research (CNRS) ERL8252, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Faculté de Médecine, Site Xavier Bichat, 16 Rue Henri Huchard, Paris 75018, France; Laboratory of Inflamex Excellency, Faculty of Medicine, Xavier Bichat Site, Paris, France
| | - Renato C Monteiro
- National French Institute of Health and Medical Research (INSERM) U1149, Centre de Recherche Sur l'Inflammation, 16 Rue Henri Huchard, Paris 75018, France; National French Center of Scientific Research (CNRS) ERL8252, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Faculté de Médecine, Site Xavier Bichat, 16 Rue Henri Huchard, Paris 75018, France; Laboratory of Inflamex Excellency, Faculty of Medicine, Xavier Bichat Site, Paris, France
| | - Marjolein Van Egmond
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, De Boelelaan 1109, 1081 HZ Amsterdam, The Netherlands; Amsterdam Infection & Immunity Institute, Amsterdam, The Netherlands; Department of Surgery, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands.
| |
Collapse
|
11
|
Lu G, Zhang X, Shen L, Qiao Q, Li Y, Sun J, Zhang J. CCL20 secreted from IgA1-stimulated human mesangial cells recruits inflammatory Th17 cells in IgA nephropathy. PLoS One 2017; 12:e0178352. [PMID: 28552941 PMCID: PMC5446182 DOI: 10.1371/journal.pone.0178352] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 05/11/2017] [Indexed: 12/22/2022] Open
Abstract
IgA nephropathy (IgAN) is the most common primary glomerulonephritis characterized by human mesangial cells (HMC) proliferation and extracellular matrix expansion associated with immune deposits consisting of galactose-deficient IgA1. However, how IgA1 contributes to IgAN has yet to be completely elucidated. In this study, the expression profile of chemokines was more altered in IgA1-treated HMC than in the control group. CCL20 was significantly higher either in the serum of IgAN patients or in IgA1-treated HMC. Further experiments demonstrated that CCR6, the only receptor of CCL20, was highly expressed in activated T cells. Intracellular staining assay and cytokine expression profile implied that CCR6+ T cells produced high IL-17 levels. Transwell experiment immunohistochemistry and immunofluorescence experiments extensively demonstrated that CCL20 could recruit inflammatory Th17 cells to the kidneys. These phenomena caused a series of immune inflammatory responses and further damaged the kidneys. Therefore, HMC stimulated by IgA1 could produce CCL20 and consequently recruit inflammatory Th17 cells to the kidneys to induce further lesion in IgA nephropathy.
Collapse
Affiliation(s)
- Guoyuan Lu
- Department of Internal Medicine, Division of Nephrology, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, People’s Republic of China
| | - Xiaopan Zhang
- Department of Internal Medicine, Division of Nephrology, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, People’s Republic of China
| | - Lei Shen
- Department of Internal Medicine, Division of Nephrology, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, People’s Republic of China
| | - Qing Qiao
- Department of Internal Medicine, Division of Nephrology, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, People’s Republic of China
| | - Yuan Li
- Department of Internal Medicine, Division of Nephrology, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, People’s Republic of China
| | - Jieqiong Sun
- Department of Internal Medicine, Division of Nephrology, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, People’s Republic of China
| | - Jinping Zhang
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, Jiangsu Province, People’s Republic of China
- * E-mail:
| |
Collapse
|
12
|
Kim MJ, Schaub S, Molyneux K, Koller MT, Stampf S, Barratt J. Effect of Immunosuppressive Drugs on the Changes of Serum Galactose-Deficient IgA1 in Patients with IgA Nephropathy. PLoS One 2016; 11:e0166830. [PMID: 27930655 PMCID: PMC5145158 DOI: 10.1371/journal.pone.0166830] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/06/2016] [Indexed: 12/25/2022] Open
Abstract
Galactose-deficient IgA1 (Gd-IgA1) and IgA-IgG complexes are known to play an important role in the pathogenesis of IgA nephropathy (IgAN). We aimed therefore to determine the impact of immunosuppression on the serum levels of Gd-IgA1, total IgA1 and IgA-IgG complexes in IgAN patients. In a retrospective study, serum samples from IgAN patients collected before transplantation (t0) and at 3- and 6-month posttransplant (t3 & t6) were used to measure the levels of Gd-IgA1, total IgA1 and IgA-IgG complexes. The area under the curves (AUC) of immunosuppressants was calculated by the plot of plasma trough level or dosage of each immunosuppressant versus time and was interpreted as the extent of drug exposure. Thirty-six out of 64 IgAN patients, who underwent kidney transplantation between 2005 and 2012, were enrolled. From t0 to t3, serum Gd-IgA1 and total IgA1 decreased significantly (24.7 AU (18.6-36.1) to 17.2 (13.1-29.5) (p<0.0001); 4.1 mg/ml (3.6-5.1) to 3.4 (3.0-4.1) (p = 0.0005)), whereas IgA-IgG complexes remained similar. From t3 to t6, Gd-IgA1 and IgA-IgG complexes significantly increased (17.2 AU (13.1-29.5) to 23.9 (16.8-32.0) (p = 0.0143); OD 0.16 (0.06-0.31) to 0.26 (0.14-0.35) (p = 0.0242)), while total IgA1 remained similar. According to median regression analysis, AUC of prednisone t0-6 was significantly associated with the decrease of Gd-IgA1 t0-6 (P = 0.01) and IgA1 t0-6 (p = 0.002), whereas AUC of tacrolimus t0-6 was associated with the decrease of IgA1 t0-6 (p = 0.02). AUC of prednisone t0-3 was associated with the decrease of IgA-IgG complexes t0-3 (p = 0.0036). The association of AUC prednisone t0-6 with Gd-IgA1 t0-6 remained highly significant after adjustment for other immunosuppressants (p = 0.0036). Serum levels of Gd-IgA1, total IgA1 and IgA-IgG in patients with IgAN vary according to the changing degrees of immunosuppression. The exposure to prednisone most clearly influenced the serum levels of Gd-IgA1.
Collapse
Affiliation(s)
- Min Jeong Kim
- Clinic for Transplantationsimmunology & Nephrology, University Hospital Basel, Basel, Switzerland
- * E-mail:
| | - Stefan Schaub
- Clinic for Transplantationsimmunology & Nephrology, University Hospital Basel, Basel, Switzerland
| | - Karen Molyneux
- Department of Infection, Immunity & Inflammation, University of Leicester, Leicester, United Kingdom
| | - Michael T. Koller
- Clinic for Transplantationsimmunology & Nephrology, University Hospital Basel, Basel, Switzerland
- Basel Institute for Clinical Epidemiology and Biostatistics, University Hospital Basel, Basel, Switzerland
| | - Susanne Stampf
- Basel Institute for Clinical Epidemiology and Biostatistics, University Hospital Basel, Basel, Switzerland
| | - Jonathan Barratt
- Department of Infection, Immunity & Inflammation, University of Leicester, Leicester, United Kingdom
| |
Collapse
|
13
|
Oka K, Nishimura K, Kishikawa H, Ichikawa Y. IgA1 dominant subclass of latent IgA mesangial deposition in donated kidney. Int J Nephrol Renovasc Dis 2016; 9:313-317. [PMID: 27942230 PMCID: PMC5136359 DOI: 10.2147/ijnrd.s120562] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background In the pathogenesis of immunoglobulin A nephropathy (IgAN), the IgA1 subclass is more important than the IgA2 subclass. In healthy men, the prevalence of mesangial IgA deposition has been previously investigated. However, it remains unknown whether the presence of urinary abnormalities depends on the subclass of IgA deposition. Materials and methods We researched the subclasses of IgA (IgA1 and IgA2) by the direct immunofluorescence (IF) staining method using specimens in which we identified the deposition of IgA through zero-hour renal transplant biopsies from donors without urinary abnormalities. The samples of the zero-hour biopsies were collected from 46 cases of living renal transplant patients at Nishinomiya Hospital, Hyogo Prefecture, from January 2011 to December 2013. Results In seven of the 46 cases (15%), IgA deposition and C3 in mesangium were confirmed. All seven cases showed IgA1 predominant mesangial deposition on IF. The results of the histological evaluations for all seven cases were Oxford Classification M0.S0.E0.T0. Conclusion This study showed similar patterns of latent mesangial IgA deposition according to IgA subclass and frequency of C3 deposition as IgAN. Latent mesangial IgA deposition may require some, as yet undefined factors, to become clinically apparent as IgAN.
Collapse
Affiliation(s)
- Kazumasa Oka
- Department of Pathology, Hyogo Prefectural Nishinomiya Hospital, Hyogo, Japan
| | - Kenji Nishimura
- Department of Urology, Hyogo Prefectural Nishinomiya Hospital, Hyogo, Japan
| | - Hidefumi Kishikawa
- Department of Urology, Hyogo Prefectural Nishinomiya Hospital, Hyogo, Japan
| | | |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Abstract
Globally, IgA nephropathy (IgAN) is the most common primary glomerulonephritis that can progress to renal failure. The exact pathogenesis of IgAN is not well defined, but current biochemical and genetic data implicate overproduction of aberrantly glycosylated IgA1. These aberrant immunoglobulins are characterized by galactose deficiency of some hinge-region O-linked glycans. However, aberrant glycosylation alone is insufficient to induce renal injury: the participation of glycan-specific IgA and IgG autoantibodies that recognize the undergalactosylated IgA1 molecule is required. Glomerular deposits of immune complexes containing undergalactosylated IgA1 activate mesangial cells, leading to the local overproduction of cytokines, chemokines and complement. Emerging data indicate that mesangial-derived mediators that are released following mesangial deposition of IgA1 lead to podocyte and tubulointerstitial injury via humoral crosstalk. Patients can present with a range of signs and symptoms, from asymptomatic microscopic haematuria to macroscopic haematuria. The clinical progression varies, with 30-40% of patients reaching end-stage renal disease 20-30 years after the first clinical presentation. Currently, no IgAN-specific therapies are available and patients are managed with the aim of controlling blood pressure and maintaining renal function. However, new therapeutic approaches are being developed, building upon our ever-improving understanding of disease pathogenesis.
Collapse
|
16
|
Abstract
Since its first description in 1968, IgA nephropathy has remained the most common form of primary glomerulonephritis leading to chronic kidney disease in developed countries. The clinical progression varies, and consequent end-stage renal disease occurs in 30% to 40% of patients 20 to 30 years after the first clinical presentation. Current data implicate overproduction of aberrantly glycosylated IgA1 as being pivotal in the induction of renal injury. Effective and specific treatment is still lacking, and new therapeutic approaches will be developed after better understanding the disease pathogenesis.
Collapse
Affiliation(s)
- Kar Neng Lai
- Nephrology Department, Hong Kong Sanatorium and Hospital, Happy Valley, Hong Kong; Nephrology Division Department of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong
| | - Joseph C K Leung
- Nephrology Division Department of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong
| | - Sydney C W Tang
- Nephrology Division Department of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong
| |
Collapse
|
17
|
Seki T, Asanuma K, Asao R, Nonaka K, Sasaki Y, Oliva Trejo JA, Kurosawa H, Hirayama Y, Horikoshi S, Tomino Y, Saito A. Significance of urinary full-length megalin in patients with IgA nephropathy. PLoS One 2014; 9:e114400. [PMID: 25502002 PMCID: PMC4264761 DOI: 10.1371/journal.pone.0114400] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 11/10/2014] [Indexed: 11/22/2022] Open
Abstract
Background and Objectives Megalin is highly expressed at the apical membranes of proximal tubular epithelial cells. A urinary full-length megalin (C-megalin) assay is linked to the severity of diabetic nephropathy in type 2 diabetes. This study examined the relationship between levels of urinary C-megalin and histological findings in adult patients with IgA nephropathy (IgAN). Design, Setting, Participants, & Measurements Urine samples voided in the morning on the day of renal biopsy were obtained from 73 patients with IgAN (29 men and 44 women; mean age, 33 years) and 5 patients with membranous nephropathy (MN). Renal pathologic variables were analyzed using the Oxford classification of IgAN, the Shigematsu classification and the Clinical Guidelines of IgAN in Japan. The levels of urinary C-megalin were measured by sandwich ELISA. Results Histological analysis based on the Oxford classification revealed that the levels of urinary C-megalin were correlated with mesangial hypercellularity in IgAN patients (OR = 1.76, 95% CI: 1.04–3.27, P<0.05). There was a significant correlation between the levels of urinary C-megalin and the severity of chronic extracapillary abnormalities according to the Shigematsu classification in IgAN patients (β = 0.33, P = 0.008). The levels of urinary C-megalin were significantly higher in all risk levels of IgAN patients requiring dialysis using the Clinical Guidelines of IgAN in Japan than in the control group. The levels of urinary C-megalin were significantly higher in the high risk and very high risk grades than in the low risk grade (P<0.05). The levels of urinary C-megalin were significantly higher in MN patients compared to the control group. Conclusions The levels of urinary C-megalin are associated with histological abnormalities in adult IgAN patients. There is a possibility that urinary C-megalin is an independent predictor of disease progression of IgAN. In addition, our results suggest that urinary C-megalin is a marker of glomerular abnormalities in various glomerular diseases as well as IgAN.
Collapse
Affiliation(s)
- Takuto Seki
- Division of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan; TMK project, Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Katsuhiko Asanuma
- Division of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan; TMK project, Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Rin Asao
- Division of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Kanae Nonaka
- Division of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan; TMK project, Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yu Sasaki
- Division of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | | | - Hiroyuki Kurosawa
- Reagents Development Department, Denka Seiken Co. Ltd., Niigata, Japan
| | - Yoshiaki Hirayama
- Reagents Development Department, Denka Seiken Co. Ltd., Niigata, Japan
| | - Satoshi Horikoshi
- Division of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Yasuhiko Tomino
- Division of Nephrology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Akihiko Saito
- Department of Applied Molecular Medicine, Niigata University Graduate School of Medicine and Dental Sciences, Niigata, Japan
| |
Collapse
|
18
|
Schmitt R, Ståhl AL, Olin AI, Kristoffersson AC, Rebetz J, Novak J, Lindahl G, Karpman D. The combined role of galactose-deficient IgA1 and streptococcal IgA-binding M Protein in inducing IL-6 and C3 secretion from human mesangial cells: implications for IgA nephropathy. THE JOURNAL OF IMMUNOLOGY 2014; 193:317-26. [PMID: 24850720 DOI: 10.4049/jimmunol.1302249] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
IgA nephropathy (IgAN) is characterized by mesangial cell proliferation and extracellular matrix expansion associated with immune deposits consisting of galactose-deficient polymeric IgA1 and C3. We have previously shown that IgA-binding regions of streptococcal M proteins colocalize with IgA in mesangial immune deposits in patients with IgAN. In the present study, the IgA-binding M4 protein from group A Streptococcus was found to bind to galactose-deficient polymeric IgA1 with higher affinity than to other forms of IgA1, as shown by surface plasmon resonance and solid-phase immunoassay. The M4 protein was demonstrated to bind to mesangial cells not via the IgA-binding region but rather via the C-terminal region, as demonstrated by flow cytometry. IgA1 enhanced binding of M4 to mesangial cells, but not vice versa. Costimulation of human mesangial cells with M4 and galactose-deficient polymeric IgA1 resulted in a significant increase in IL-6 secretion compared with each stimulant alone. Galactose-deficient polymeric IgA1 alone, but not M4, induced C3 secretion from the cells, and costimulation enhanced this effect. Additionally, costimulation enhanced mesangial cell proliferation compared with each stimulant alone. These results indicate that IgA-binding M4 protein binds preferentially to galactose-deficient polymeric IgA1 and that these proteins together induce excessive proinflammatory responses and proliferation of human mesangial cells. Thus, tissue deposition of streptococcal IgA-binding M proteins may contribute to the pathogenesis of IgAN.
Collapse
Affiliation(s)
- Roland Schmitt
- Department of Pediatrics, Clinical Sciences Lund, Lund University, 22185 Lund, Sweden
| | - Anne-Lie Ståhl
- Department of Pediatrics, Clinical Sciences Lund, Lund University, 22185 Lund, Sweden
| | - Anders I Olin
- Department of Infection Medicine, Clinical Sciences Lund, Lund University, 22185 Lund, Sweden
| | | | - Johan Rebetz
- Department of Pediatrics, Clinical Sciences Lund, Lund University, 22185 Lund, Sweden
| | - Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294; and
| | - Gunnar Lindahl
- Division of Medical Microbiology, Department of Laboratory Medicine, Lund University, 22362 Lund, Sweden
| | - Diana Karpman
- Department of Pediatrics, Clinical Sciences Lund, Lund University, 22185 Lund, Sweden;
| |
Collapse
|
19
|
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: 124] [Impact Index Per Article: 12.4] [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.
Collapse
Affiliation(s)
- Hitoshi Suzuki
- From the University of Alabama at Birmingham, Birmingham, Alabama 35294
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Hua KF, Yang SM, Kao TY, Chang JM, Chen HL, Tsai YJ, Chen A, Yang SS, Chao LK, Ka SM. Osthole mitigates progressive IgA nephropathy by inhibiting reactive oxygen species generation and NF-κB/NLRP3 pathway. PLoS One 2013; 8:e77794. [PMID: 24204969 PMCID: PMC3810132 DOI: 10.1371/journal.pone.0077794] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Accepted: 09/04/2013] [Indexed: 12/31/2022] Open
Abstract
Renal reactive oxygen species (ROS) and mononuclear leukocyte infiltration are involved in the progressive stage (exacerbation) of IgA nephropathy (IgAN), which is characterized by glomerular proliferation and renal inflammation. The identification of the mechanism responsible for this critical stage of IgAN and the development of a therapeutic strategy remain a challenge. Osthole is a pure compound isolated from Cnidiummonnieri (L.) Cusson seeds, which are used as a traditional Chinese medicine, and is anti-inflammatory, anti-apoptotic, and anti-fibrotic both in vitro and in vivo. Recently, we showed that osthole acts as an anti-inflammatory agent by reducing nuclear factor-kappa B (NF-κB) activation in and ROS release by activated macrophages. In this study, we examined whether osthole could prevent the progression of IgAN using a progressive IgAN (Prg-IgAN) model in mice. Our results showed that osthole administration resulted in prevention of albuminuria, improved renal function, and blocking of renal progressive lesions, including glomerular proliferation, glomerular sclerosis, and periglomerular mononuclear leukocyte infiltration. These findings were associated with (1) reduced renal superoxide anion levels and increased Nrf2 nuclear translocation, (2) inhibited renal activation of NF-κB and the NLRP3 inflammasome, (3) decreased renal MCP-1 expression and mononuclear leukocyte infiltration, (4) inhibited ROS production and NLRP3 inflammasome activation in cultured, activated macrophages, and (5) inhibited ROS production and MCP-1 protein levels in cultured, activated mesangial cells. The results suggest that osthole exerts its reno-protective effects on the progression of IgAN by inhibiting ROS production and activation of NF-κB and the NLRP3 inflammasome in the kidney. Our data also confirm that ROS generation and activation of NF-κB and the NLRP3 inflammasome are crucial mechanistic events involved in the progression of the renal disorder.
Collapse
Affiliation(s)
- Kuo-Feng Hua
- Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan, Republic of China
| | - Shun-Min Yang
- Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Tzu-Yang Kao
- Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan, Republic of China
| | - Jia-Ming Chang
- Department of Pharmacology, Institute for Drug Evaluation Platform, Development Center for Biotechnology, Taipei, Taiwan, Republic of China
| | - Hui-Ling Chen
- IND Core Team, Institute for Drug Evaluation Platform, Development Center for Biotechnology, Taipei, Taiwan, Republic of China
| | - Yung-Jen Tsai
- Department of Pharmacology, Institute for Drug Evaluation Platform, Development Center for Biotechnology, Taipei, Taiwan, Republic of China
| | - Ann Chen
- Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Sung-Sen Yang
- Division of Nephrology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Louis Kuoping Chao
- Department of Cosmeceutics, China Medical University, Taichung, Taiwan, Republic of China
| | - Shuk-Man Ka
- Graduate Institute of Aerospace and Undersea Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China
- * E-mail:
| |
Collapse
|
21
|
Xu LX, Ye ZM, Feng Z, Xin G, Zhang B, Liu S, Li R, Li Z, Liang X, Shi W. N-acetylgalactosamine exposure of serum IgA1 was associated with glomerulosclerosis and tubular atrophy/interstitial fibrosis of IgA nephropathy patients. Nephrology (Carlton) 2013; 19:32-9. [PMID: 24131475 DOI: 10.1111/nep.12169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2013] [Indexed: 11/28/2022]
Abstract
AIM Immunoglobulin A nephropathy (IgAN) is the most common glomerulonephritis with various histological and clinical phenotypes. N-acetylgalactosamine (GalNAc) exposure plays a pivotal role in the pathogenesis of IgAN. The aim of the current study is to investigate whether GalNAc exposure of serum IgA1 was associated with clinical and pathological manifestation of IgAN. METHODS Sera from 199 patients with biopsy proved IgAN were collected. Clinical and pathological manifestations were collected. Biotinylated Helix aspersa were used in ELISA to examine GalNAc exposure on IgA1 molecules. Patients were divided into two groups according to the GalNAc exposure rate less or more than 0.4. RESULTS Age, gender, and serum creatinine were comparable between the two groups. Univariate analysis showed that significantly higher urinary protein excretion rate but less severe glomerular sclerosis and tubularinterstitial fibrosis were observed in the lower GalNAc exposure group. Multivariate regression analysis demonstrated that adjusted by age and gender, the GalNAc exposure rate more than 0.4 was a risk factor of glomerular sclerosis and tubularinterstitial fibrosis, OR*(95% CI) were 2.76 (1.19-6.37) and 2.49 (1.18-5.25), respectively. CONCLUSION Immunoglobulin A nephropathy patients with lower proteinuria had higher GalNAc exposure rates. The GalNAc exposure rate more than 0.4 was a risk factor of severe chronic renal tissue change.
Collapse
Affiliation(s)
- Li-Xia Xu
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Synergistic effect of mesangial cell-induced CXCL1 and TGF-β1 in promoting podocyte loss in IgA nephropathy. PLoS One 2013; 8:e73425. [PMID: 24023680 PMCID: PMC3758267 DOI: 10.1371/journal.pone.0073425] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 07/21/2013] [Indexed: 12/12/2022] Open
Abstract
Podocyte loss has been reported to relate to disease severity and progression in IgA nephropathy (IgAN). However, the underlying mechanism for its role in IgAN remain unclear. Recent evidence has shown that IgA1 complexes from patients with IgAN could activate mesangial cells to induce soluble mediator excretion, and further injure podocytes through mesangial-podocytic cross-talk. In the present study, we explored the underlying mechanism of mesangial cell-induced podocyte loss in IgAN. We found that IgA1 complexes from IgAN patients significantly up-regulated the expression of CXCL1 and TGF-β1 in mesangial cells compared with healthy controls. Significantly higher urinary levels of CXCL1 and TGF-β1 were also observed in patients with IgAN compared to healthy controls. Moreover, IgAN patients with higher urinary CXCL1 and TGF-β1 presented with severe clinical and pathological manifestations, including higher 24-hour urine protein excretion, lower eGFR and higher cresentic glomeruli proportion. Further in vitro experiments showed that increased podocyte death and reduced podocyte adhesion were induced by mesangial cell conditional medium from IgAN (IgAN-HMCM), as well as rhCXCL1 together with rhTGF-β1. In addition, the over-expression of CXCR2, the receptor for CXCL1, by podocytes was induced by IgAN-HMCM and rhTGF-β1, but not by rhCXCL1. Furthermore, the effect of increased podocyte death and reduced podocyte adhesion induced by IgAN-HMCM and rhCXCL1 and rhTGF-β1 was rescued partially by a blocking antibody against CXCR2. Moreover, we observed the expression of CXCR2 in urine exfoliated podocytes in IgAN patients. Our present study implied that IgA1 complexes from IgAN patients could up-regulate the secretion of CXCL1 and TGF-β1 in mesangial cells. Additionally, the synergistic effect of CXCL1 and TGF-β1 further induced podocyte death and adhesion dysfunction in podocytes via CXCR2. This might be a potential mechanism for podocyte loss observed in IgAN.
Collapse
|
23
|
Kim MJ, Tam FWK. Currently available and potential future treatment options for IgA nephropathy. Expert Opin Orphan Drugs 2013. [DOI: 10.1517/21678707.2013.821949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
24
|
Mestecky J, Raska M, Julian BA, Gharavi AG, Renfrow MB, Moldoveanu Z, Novak L, Matousovic K, Novak J. IgA nephropathy: molecular mechanisms of the disease. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2012; 8:217-40. [PMID: 23092188 DOI: 10.1146/annurev-pathol-011110-130216] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Studies of molecular and cellular interactions involved in the pathogenesis of IgA nephropathy have revealed the autoimmune nature of this most common primary glomerulonephritis. In patients with this disease, altered glycan structures in the unique hinge region of the heavy chains of IgA1 molecules lead to the exposure of antigenic determinants, which are recognized by naturally occurring antiglycan antibodies of the IgG and/or IgA1 isotype. As a result, nephritogenic immune complexes form in the circulation and deposit in the glomerular mesangium. Deposited immune complexes induce proliferation of resident mesangial cells, increased production of extracellular matrix proteins and cytokines, and ultimately loss of glomerular function. Structural elucidation of the nature of these immune complexes and their biological activity should provide a rational basis for an effective, immunologically mediated inhibition of the formation of nephritogenic immune complexes that could be used as a disease-specific therapeutic approach.
Collapse
Affiliation(s)
- Jiri Mestecky
- Department of Microbiology, University of Alabama at Birmingham, AL 35294, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Zhao N, Hou P, Lv J, Moldoveanu Z, Li Y, Kiryluk K, Gharavi AG, Novak J, Zhang H. The level of galactose-deficient IgA1 in the sera of patients with IgA nephropathy is associated with disease progression. Kidney Int 2012; 82:790-6. [PMID: 22673888 PMCID: PMC3443545 DOI: 10.1038/ki.2012.197] [Citation(s) in RCA: 178] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Although high serum levels of galactose-deficient IgA1 (an important biomarker of IgA nephropathy (IgAN)) are found in most patients with IgAN, their relationship to disease severity and progression remains unclear. To help clarify this we prospectively enrolled 275 patients with IgAN and followed them for a median of 47 months (range 12-96 months). Serum galactose-deficient IgA1 was measured at the time of diagnosis using a lectin-based ELISA, and renal survival was modeled using the Cox proportional hazards method. The serum levels of galactose-deficient IgA1 were higher in patients with IgAN compared to those in healthy controls. Importantly, in adjusted analysis, higher levels of galactose-deficient IgA1 were independently associated with a greater risk of deterioration in renal function with a hazard ratio of 1.44 per standard deviation of the natural log-transformed galactose-deficient IgA1 concentration. In reference to the first quartile, the risk of kidney failure increased such that the hazard ratio for the second quartile was 2.47, 3.86 for the third, and 4.76 for the fourth quartile of the galactose-deficient IgA1 concentration. Hence, elevated serum levels of galactose-deficient IgA1 are associated with a poor prognosis in IgAN.
Collapse
Affiliation(s)
- Na Zhao
- Renal Division, Department of Medicine, Peking University First Hospital; Peking University Institute of Nephrology; Key Laboratory of Renal Disease, Ministry of Health of China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education; Beijing, China
| | - Ping Hou
- Renal Division, Department of Medicine, Peking University First Hospital; Peking University Institute of Nephrology; Key Laboratory of Renal Disease, Ministry of Health of China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education; Beijing, China
| | - Jicheng Lv
- Renal Division, Department of Medicine, Peking University First Hospital; Peking University Institute of Nephrology; Key Laboratory of Renal Disease, Ministry of Health of China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education; Beijing, China
| | - Zina Moldoveanu
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yifu Li
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Krzysztof Kiryluk
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Ali G. Gharavi
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hong Zhang
- Renal Division, Department of Medicine, Peking University First Hospital; Peking University Institute of Nephrology; Key Laboratory of Renal Disease, Ministry of Health of China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education; Beijing, China
| |
Collapse
|
26
|
Kim MJ, McDaid JP, McAdoo SP, Barratt J, Molyneux K, Masuda ES, Pusey CD, Tam FWK. Spleen tyrosine kinase is important in the production of proinflammatory cytokines and cell proliferation in human mesangial cells following stimulation with IgA1 isolated from IgA nephropathy patients. THE JOURNAL OF IMMUNOLOGY 2012; 189:3751-8. [PMID: 22956578 DOI: 10.4049/jimmunol.1102603] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
IgA immune complexes are capable of inducing human mesangial cell (HMC) activation, resulting in release of proinflammatory and profibrogenic mediators. The subsequent inflammation, cellular proliferation, and synthesis of extracellular matrix lead to the progression of IgA nephropathy (IgAN). Spleen tyrosine kinase (SYK) is an intracellular protein tyrosine kinase involved in cell signaling downstream of immunoreceptors. In this study, we determined whether SYK is involved in the downstream signaling of IgA1 stimulation in HMC, leading to production of proinflammatory cytokines/chemokines and cell proliferation. Incubation of HMC with IgA1 purified from IgAN patients significantly increased the synthesis of MCP-1 in a dose-dependent manner. There was also significantly increased production of IL-6, IL-8, IFN-γ-inducible protein-10, RANTES, and platelet-derived growth factor-BB. Stimulation of HMC with heat-aggregated IgA1 purified from IgAN patients induced significantly increased HMC proliferation. Both pharmacological inhibition of SYK and knockdown of SYK by small interfering RNA significantly reduced the synthesis of these mediators and inhibited HMC proliferation. Moreover, positive immunostaining for total and phospho-SYK in glomeruli of kidney biopsies from IgAN patients strongly suggests the involvement of SYK in the pathogenesis of IgAN. To our knowledge, we demonstrate, for the first time, the involvement of SYK in the downstream signaling of IgA1 stimulation in HMC and in the pathogenesis of IgAN. Hence, SYK represents a potential therapeutic target for IgAN.
Collapse
Affiliation(s)
- Min Jeong Kim
- Imperial College Kidney and Transplant Institute, Hammersmith Hospital, Imperial College London, London W12 0NN, United Kingdom.
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Abstract
Since its first description in 1968, IgA nephropathy has remained the most common form of idiopathic glomerulonephritis leading to chronic kidney disease in developed countries. The exact pathogenesis of IgA nephropathy is still not well defined. Current data implicate an important genetic factor, especially in promoting the overproduction of an aberrant form of IgA1. The immunochemical aberrancy of IgA nephropathy is characterized by the undergalactosylation of O-glycans in the hinge region of IgA1. However, such aberrant glycosylation alone does not cause renal injury. The next stage of disease development requires the formation of glycan-specific IgG and IgA antibodies that recognize the undergalactosylated IgA1 molecule. These antibodies often have reactivity against antigens from extrinsic microorganisms and might arise from recurrent mucosal infection. B cells that respond to mucosal infections, particularly tonsillitis, might produce the nephritogenic IgA1 molecule. With increased immune-complex formation and decreased clearance owing to reduced uptake by the liver, IgA1 binds to the glomerular mesangium via an as yet unidentified receptor. Glomerular IgA1 deposits trigger the local production of cytokines and growth factors, leading to the activation of mesangial cells and the complement system. Emerging data suggest that mesangial-derived mediators following glomerular deposition of IgA1 lead to podocyte and tubulointerstitial injury via mesangio-podocytic-tubular crosstalk. This Review summarizes the latest findings in the pathogenesis of IgA nephropathy.
Collapse
Affiliation(s)
- Kar Neng Lai
- Nephrology Center, 10th floor, Li Shu Pui Block, Hong Kong Sanatorium and Hospital, 2 Village Road, Happy Valley, Hong Kong.
| |
Collapse
|
28
|
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.
Collapse
Affiliation(s)
- Takeshi Yanagihara
- Department of Microbiology, University of Alabama, Birmingham, AL, USA ; Department of Pediatrics, Nippon Medical School, Tokyo, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Scindia YM, Deshmukh US, Bagavant H. Mesangial pathology in glomerular disease: targets for therapeutic intervention. Adv Drug Deliv Rev 2010; 62:1337-43. [PMID: 20828589 DOI: 10.1016/j.addr.2010.08.011] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2010] [Revised: 07/13/2010] [Accepted: 08/31/2010] [Indexed: 12/17/2022]
Abstract
The glomerulus is the filtration unit of the kidney. Disruption of glomerular function may be caused by primary glomerular pathology or secondary to systemic diseases. The mesangial, endothelial and epithelial cells of the glomerulus are involved in most pathologic processes. Animal models provide an understanding of the molecular basis of glomerular disease. These studies show that mesangial cells are critical players in the initiation and progression of disease. Therefore, modulation of mesangial cell responses offers a novel therapeutic approach. The complex architecture of the kidney, specifically the renal glomerulus, makes targeted drug delivery especially challenging. Targeted delivery of therapeutic agents reduces dose of administration and minimises unwanted side effects caused by toxicity to other tissues. The currently available modalities demonstrating the feasibility of mesangial cell targeting are discussed.
Collapse
Affiliation(s)
- Yogesh M Scindia
- Department of Medicine, University of Virginia, Charlottesville, 22908, USA
| | | | | |
Collapse
|
30
|
Kiryluk K, Julian BA, Wyatt RJ, Scolari F, Zhang H, Novak J, Gharavi AG. Genetic studies of IgA nephropathy: past, present, and future. Pediatr Nephrol 2010; 25:2257-68. [PMID: 20386929 PMCID: PMC2937145 DOI: 10.1007/s00467-010-1500-7] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 01/08/2010] [Accepted: 01/30/2010] [Indexed: 11/24/2022]
Abstract
Immunoglobulin A nephropathy (IgAN) is the most common form of primary glomerulonephritis worldwide and an important cause of kidney disease in young adults. Highly variable clinical presentation and outcome of IgAN suggest that this diagnosis may encompass multiple subsets of disease that are not distinguishable by currently available clinical tools. Marked differences in disease prevalence between individuals of European, Asian, and African ancestry suggest the existence of susceptibility genes that are present at variable frequencies in these populations. Familial forms of IgAN have also been reported throughout the world but are probably underrecognized because associated urinary abnormalities are often intermittent in affected family members. Of the many pathogenic mechanisms reported, defects in IgA1 glycosylation that lead to formation of immune complexes have been consistently demonstrated. Recent data indicates that these IgA1 glycosylation defects are inherited and constitute a heritable risk factor for IgAN. Because of the complex genetic architecture of IgAN, the efforts to map disease susceptibility genes have been difficult, and no causative mutations have yet been identified. Linkage-based approaches have been hindered by disease heterogeneity and lack of a reliable noninvasive diagnostic test for screening family members at risk of IgAN. Many candidate-gene association studies have been published, but most suffer from small sample size and methodological problems, and none of the results have been convincingly validated. New genomic approaches, including genome-wide association studies currently under way, offer promising tools for elucidating the genetic basis of IgAN.
Collapse
Affiliation(s)
- Krzysztof Kiryluk
- Department of Medicine, Division of Nephrology, College of Physicians and Surgeons, Columbia University, 1150 St. Nicholas Avenue, Russ Berrie Pavilion #413, New York, NY 10032 USA
| | - Bruce A. Julian
- Departments of Microbiology and Medicine, University of Alabama at Birmingham, Birmingham, AL USA
| | - Robert J. Wyatt
- Division of Pediatric Nephrology, Department of Pediatrics, Children’s Foundation Research Center at the Le Bonheur Children’s Medical Center, University of Tennessee Health Sciences Center, Memphis, TN USA
| | | | - Hong Zhang
- Renal Division of First Hospital, Institute of Nephrology, Peking University, Beijing, China
| | - Jan Novak
- Departments of Microbiology and Medicine, University of Alabama at Birmingham, Birmingham, AL USA
| | - Ali G. Gharavi
- Department of Medicine, Division of Nephrology, College of Physicians and Surgeons, Columbia University, 1150 St. Nicholas Avenue, Russ Berrie Pavilion #413, New York, NY 10032 USA
| |
Collapse
|
31
|
Tam KY, Leung JCK, Chan LYY, Lam MF, Tang SCW, Lai KN. In vitro enhanced chemotaxis of CD25+ mononuclear cells in patients with familial IgAN through glomerulotubular interactions. Am J Physiol Renal Physiol 2010; 299:F359-68. [PMID: 20484297 DOI: 10.1152/ajprenal.00664.2009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tubulointerstitial infiltration of immunocompetent cells is often associated with a more rapid progression in IgA nephropathy (IgAN). Using an in vitro Transwell coculture system, we examined the chemotactic response of peripheral blood mononuclear cells to proximal tubular epithelial cells (PTEC) following activation by conditioned medium prepared from mesangial cells cultured with macromolecular IgA1 from 60 patients with multiplex familial IgAN (MpIgAN) and 91 of their asymptomatic relatives; 43 patients with sporadic IgAN (SpIgAN) and 90 of their asymptomatic relatives; and 43 healthy subjects. Compared with SpIgAN patients, PTEC activated by conditioned medium from patients with MpIgAN had elevated gene expression of a spectrum of C-C, C-X-C chemokines and proinflammatory cytokines, with prominent expressions of interleukin-6, interleukin-8, and tumor necrosis factor-α. In response to conditioned medium from patients with familial IgAN, there was a significant increase in chemotaxis of CD45+ cells, CD3+, CD4+, CD8+, CD20+ lymphocytes, and monocytes with CD25 expression. Our findings suggest that compared with SpIgAN patients, macromolecular IgA1 taken from MpIgAN patients is more pathogenic to cultured PTEC through a glomerulotubular interaction. A long-term follow-up is needed to better define the prognostic course for familial IgAN and to clarify the risk of developing IgAN in initially asymptomatic relatives from a multiplex IgAN family.
Collapse
Affiliation(s)
- Ka Ying Tam
- Department of Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong, China
| | - Joseph C. K. Leung
- Department of Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong, China
| | - Loretta Y. Y. Chan
- Department of Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong, China
| | - Man Fai Lam
- Department of Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong, China
| | - Sydney C. W. Tang
- Department of Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong, China
| | - Kar Neng Lai
- Department of Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong, China
| |
Collapse
|