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Kistler AD, Salant DJ. Complement activation and effector pathways in membranous nephropathy. Kidney Int 2024; 105:473-483. [PMID: 38142037 DOI: 10.1016/j.kint.2023.10.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/25/2023] [Accepted: 10/05/2023] [Indexed: 12/25/2023]
Abstract
Complement activation has long been recognized as a central feature of membranous nephropathy (MN). Evidence for its role has been derived from the detection of complement products in biopsy tissue and urine from patients with MN and from mechanistic studies primarily based on the passive Heymann nephritis model. Only recently, more detailed insights into the exact mechanisms of complement activation and effector pathways have been gained from patient data, animal models, and in vitro models based on specific target antigens relevant to the human disease. These data are of clinical relevance, as they parallel the recent development of numerous specific complement therapeutics for clinical use. Despite efficient B-cell depletion, many patients with MN achieve only partial remission of proteinuria, which may be explained by the persistence of subepithelial immune complexes and ongoing complement-mediated podocyte injury. Targeting complement, therefore, represents an attractive adjunct treatment for MN, but it will need to be tailored to the specific complement pathways relevant to MN. This review summarizes the different lines of evidence for a central role of complement in MN and for the relevance of distinct complement activation and effector pathways, with a focus on recent developments.
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Affiliation(s)
- Andreas D Kistler
- Department of Medicine, Cantonal Hospital Frauenfeld, Spital Thurgau AG, Frauenfeld, Switzerland; Faculty of Medicine, University of Zurich, Zurich, Switzerland.
| | - David J Salant
- Section of Nephrology, Department of Medicine, Boston Medical Center and Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts, USA
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So BYF, Chan GCW, Yap DYH, Chan TM. The role of the complement system in primary membranous nephropathy: A narrative review in the era of new therapeutic targets. Front Immunol 2022; 13:1009864. [PMID: 36353636 PMCID: PMC9639362 DOI: 10.3389/fimmu.2022.1009864] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 10/12/2022] [Indexed: 11/14/2022] Open
Abstract
Primary membranous nephropathy (MN) is an important cause of nephrotic syndrome and chronic kidney disease (CKD) in the adult population. Although the discovery of different autoantibodies against glomerular/podocytic antigens have highlighted the role of B cells in the pathogenesis of MN, suboptimal response or even resistance to B cell-directed therapies occurs, suggesting that other pathophysiological mechanisms are involved in mediating podocyte injury. The complement system plays an important role in the innate immune response to infection, and dysregulation of the complement system has been observed in various kidney diseases. There is compelling evidence of complement cascade activation in primary MN, with the mannose-binding lectin (MBL) and alternative pathways particularly implicated. With appropriate validation, assays of complements and associated activation products could hold promise as adjunctive tools for non-invasive disease monitoring and prognostication. While there is growing interest to target the complement system in MN, there is concern regarding the risk of infection due to encapsulated organisms and high treatment costs, highlighting the need for clinical trials to identify patients most likely to benefit from complement-directed therapies.
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Kamyshova ES, Semeryuk TA, Bobkova IN. Modern view on the complement system role in membranous nephropathy. TERAPEVT ARKH 2022; 94:772-776. [DOI: 10.26442/00403660.2022.06.201563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 08/04/2022] [Indexed: 11/22/2022]
Abstract
Membranous nephropathy (MN), an immune-mediated glomerular disease, is the most common cause of adult nephrotic syndrome. In MN, proteinuria is developed by podocyte damage due to the complement system activation in response to the subepithelial deposition of immune complexes containing various auto- and exogenous antigens. Membrane-attacking complex (MAC) is the terminal product of any complement pathways activation (classical, lectin or alternative) and plays the leading role in the complement-mediated podocytic damage. Thus far, the main pathway of complement activation leading to the formation of MAC in MN has not been established. The review highlights current evidence of various complement pathways activation in the development of MN, as well as recently established new molecular mechanisms of complement-mediated podocyte damage.
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Mühlig AK, Keir LS, Abt JC, Heidelbach HS, Horton R, Welsh GI, Meyer-Schwesinger C, Licht C, Coward RJ, Fester L, Saleem MA, Oh J. Podocytes Produce and Secrete Functional Complement C3 and Complement Factor H. Front Immunol 2020; 11:1833. [PMID: 32922395 PMCID: PMC7457071 DOI: 10.3389/fimmu.2020.01833] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 07/08/2020] [Indexed: 12/20/2022] Open
Abstract
Podocytes are an important part of the glomerular filtration barrier and the key player in the development of proteinuria, which is an early feature of complement mediated renal diseases. Complement factors are mainly liver-born and present in circulation. Nevertheless, there is a growing body of evidence for additional sites of complement protein synthesis, including various cell types in the kidney. We hypothesized that podocytes are able to produce complement components and contribute to the local balance of complement activation and regulation. To investigate the relevant balance between inhibiting and activating sides, our studies focused on complement factor H (CFH), an important complement regulator, and on C3, the early key component for complement activation. We characterized human cultured podocytes for the expression and secretion of activating and regulating complement factors, and analyzed the secretion pathway and functional activity. We studied glomerular CFH and C3 expression in puromycin aminonucleoside (PAN) -treated rats, a model for proteinuria, and the physiological mRNA-expression of both factors in murine kidneys. We found, that C3 and CFH were expressed in cultured podocytes and expression levels differed from those in cultivated glomerular endothelial cells. The process of secretion in podocytes was stimulated with interferon gamma and located in the Golgi apparatus. Cultured podocytes could initiate the complement cascade by the splitting of C3, which can be shown by the generation of C3a, a functional C3 split product. C3 contributed to external complement activation. Podocyte-secreted CFH, in conjunction with factor I, was able to split C3b. Podocytes derived from a patient with a CFH mutation displayed impaired cell surface complement regulation. CFH and C3 were synthesized in podocytes of healthy C57Bl/6-mice and were upregulated in podocytes of PAN treated rats. These data show that podocytes produce functionally active complement components, and could therefore influence the local glomerular complement activation and regulation. This modulating effect should therefore be considered in all diseases where glomerular complement activation occurs. Furthermore, our data indicate a potential novel role of podocytes in the innate immune system.
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Affiliation(s)
- Anne K. Mühlig
- University Children's Research@Kinder-UKE, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Department of Pediatric Nephrology, University Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lindsay S. Keir
- Bristol Renal and Children's Renal Unit, University of Bristol, Bristol, United Kingdom
| | - Jana C. Abt
- Department of Pediatric Nephrology, University Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Hannah S. Heidelbach
- Department of Pediatric Nephrology, University Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Rachel Horton
- Bristol Renal and Children's Renal Unit, University of Bristol, Bristol, United Kingdom
| | - Gavin I. Welsh
- Bristol Renal and Children's Renal Unit, University of Bristol, Bristol, United Kingdom
| | - Catherine Meyer-Schwesinger
- Center of Experimental Medicine, Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph Licht
- Division of Pediatric Nephrology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Richard J. Coward
- Bristol Renal and Children's Renal Unit, University of Bristol, Bristol, United Kingdom
| | - Lars Fester
- Department of Neuroanatomy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Institute for Anatomy and Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Moin A. Saleem
- Bristol Renal and Children's Renal Unit, University of Bristol, Bristol, United Kingdom
| | - Jun Oh
- University Children's Research@Kinder-UKE, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Department of Pediatric Nephrology, University Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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5
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Rangan GK. C5b-9 does not mediate tubulointerstitial injury in experimental acute glomerular disease characterized by selective proteinuria. World J Nephrol 2016; 5:288-299. [PMID: 27152265 PMCID: PMC4848152 DOI: 10.5527/wjn.v5.i3.288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 03/14/2016] [Indexed: 02/06/2023] Open
Abstract
AIM: To determine whether complement membrane attack complex (C5b-9) has a pathogenic role in tubulointerstitial injury in a renal disease model characterized by acute highly selective proteinuria.
METHODS: Protein-overload nephropathy (PON) was induced in adult female Piebald-Viral-Glaxo rats with or without complement C6 deficiency (C6- and C6+) by daily intraperitoneal injections of bovine serum albumin (BSA, 2 g/d), and examined on days 2, 4 and 8.
RESULTS: Groups with PON developed equivalent levels of heavy proteinuria within 24 h of BSA injection. In C6+ rats with PON, the tubulointerstitial expression of C5b-9 was increased and localized predominantly to the basolateral surface of tubular epithelial cells (TECs), whereas it was undetectable in C6- animals. TEC proliferation (as assessed by the number of BrdU+ cells) increased by more than 50-fold in PON, peaking on day 2 and declining on days 4 to 8. There was a trend for a reduction in the number of BrdU+ TECs on day 4 in the C6- PON group (P = 0.10 compared to C6+) but not at any other time-point. Kidney enlargement, TEC apoptosis (TUNEL+ cells) and markers of tubular injury (tubule dilatation, loss of TEC height, protein cast formation) were not altered by C6 deficiency in PON. Interstitial monocyte (ED-1+ cell) accumulation was partially reduced in C6- animals with PON on day 4 (P = 0.01) but there was no change in myofibroblast accumulation.
CONCLUSION: These data suggest that C5b-9 does not mediate tubulointerstitial injury in acute glomerular diseases characterized by selective proteinuria.
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Li X, Ding F, Zhang X, Li B, Ding J. The Expression Profile of Complement Components in Podocytes. Int J Mol Sci 2016; 17:471. [PMID: 27043537 PMCID: PMC4848927 DOI: 10.3390/ijms17040471] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 03/14/2016] [Accepted: 03/23/2016] [Indexed: 01/10/2023] Open
Abstract
Podocytes are critical for maintaining the glomerular filtration barrier and are injured in many renal diseases, especially proteinuric kidney diseases. Recently, reports suggested that podocytes are among the renal cells that synthesize complement components that mediate glomerular diseases. Nevertheless, the profile and extent of complement component expression in podocytes remain unclear. This study examined the expression profile of complement in podocytes under physiological conditions and in abnormal podocytes induced by multiple stimuli. In total, 23/32 complement component components were detected in podocyte by conventional RT-PCR. Both primary cultured podocytes and immortalized podocytes expressed the complement factors C1q, C1r, C2, C3, C7, MASP, CFI, DAF, CD59, C4bp, CD46, Protein S, CR2, C1qR, C3aR, C5aR, and Crry (17/32), whereas C4, CFB, CFD, C5, C6, C8, C9, MBL1, and MBL2 (9/32) complement factors were not expressed. C3, Crry, and C1q-binding protein were detected by tandem mass spectrometry. Podocyte complement gene expression was affected by several factors (puromycin aminonucleoside (PAN), angiotensin II (Ang II), interleukin-6 (IL-6), and transforming growth factor-β (TGF-β)). Representative complement components were detected using fluorescence confocal microscopy. In conclusion, primary podocytes express various complement components at the mRNA and protein levels. The complement gene expressions were affected by several podocyte injury factors.
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Affiliation(s)
- Xuejuan Li
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.
| | - Fangrui Ding
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.
| | - Xiaoyan Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.
| | - Baihong Li
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.
| | - Jie Ding
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.
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Eculizumab reduces complement activation, inflammation, endothelial damage, thrombosis, and renal injury markers in aHUS. Blood 2015; 125:3253-62. [PMID: 25833956 DOI: 10.1182/blood-2014-09-600411] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 03/16/2015] [Indexed: 12/30/2022] Open
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a genetic, life-threatening disease characterized by uncontrolled complement activation, systemic thrombotic microangiopathy (TMA), and vital organ damage. We evaluated the effect of terminal complement blockade with the anti-C5 monoclonal antibody eculizumab on biomarkers of cellular processes involved in TMA in patients with aHUS longitudinally, during up to 1 year of treatment, compared with in healthy volunteers. Biomarker levels were elevated at baseline in most patients, regardless of mutational status, plasma exchange/infusion use, platelet count, or lactate dehydrogenase or haptoglobin levels. Eculizumab reduced terminal complement activation (C5a and sC5b-9) and renal injury markers (clusterin, cystatin-C, β2-microglobulin, and liver fatty acid binding protein-1) to healthy volunteer levels and reduced inflammation (soluble tumor necrosis factor receptor-1), coagulation (prothrombin fragment F1+2 and d-dimer), and endothelial damage (thrombomodulin) markers to near-normal levels. Alternative pathway activation (Ba) and endothelial activation markers (soluble vascular cell adhesion molecule-1) decreased but remained elevated, reflecting ongoing complement activation in aHUS despite complete terminal complement blockade. These results highlight links between terminal complement activation and inflammation, endothelial damage, thrombosis, and renal injury and underscore ongoing risk for systemic TMA and progression to organ damage. Further research regarding underlying complement dysregulation is warranted. This trial was registered at www.clinicaltrials.gov as #NCT01194973.
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Fearn A, Sheerin NS. Complement activation in progressive renal disease. World J Nephrol 2015; 4:31-40. [PMID: 25664245 PMCID: PMC4317626 DOI: 10.5527/wjn.v4.i1.31] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 11/14/2014] [Accepted: 12/10/2014] [Indexed: 02/06/2023] Open
Abstract
Chronic kidney disease (CKD) is common and the cause of significant morbidity and mortality. The replacement of functioning nephrons by fibrosis is characteristic of progressive disease. The pathways that lead to fibrosis are not fully understood, although chronic non-resolving inflammation in the kidney is likely to drive the fibrotic response that occurs. In patients with progressive CKD there is histological evidence of inflammation in the interstitium and strategies that reduce inflammation reduce renal injury in pre-clinical models of CKD. The complement system is an integral part of the innate immune system but also augments adaptive immune responses. Complement activation is known to occur in many diverse renal diseases, including glomerulonephritis, thrombotic microangiopathies and transplant rejection. In this review we discuss current evidence that complement activation contributes to progression of CKD, how complement could cause renal inflammation and whether complement inhibition would slow progression of renal disease.
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Yanai R, Thanos A, Connor KM. Complement involvement in neovascular ocular diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 946:161-83. [PMID: 21948368 DOI: 10.1007/978-1-4614-0106-3_10] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Pathological neovascularization (NV) is a hallmark of late stage neovascular age-related macular degeneration (AMD), diabetic retinopathy (DR), and retinopathy of prematurity (ROP). There is accumulating evidence that alterations in inflammatory and immune system pathways that arise from genetic differences, injury, and disease can predispose individuals to retinal neovascular eye diseases. Yet the mechanism of disease progression with respect to the complement system in these maladies is not fully understood. Recent studies have implicated the complement system as an emerging player in the etiology of several retinal diseases. We will summarize herein several of the complement system pathways known to be involved in ocular neovascular pathologies. Current treatment for many neovascular eye diseases focuses on suppression of NV with laser ablation, photodynamic therapy, or anti-VEGF angiogenic inhibitors. However, these treatments do not address the underlying cause of many of these diseases. A clear understanding of the cellular and molecular mechanisms could bring a major shift in our approach to disease treatment and prevention.
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Affiliation(s)
- Ryoji Yanai
- Angiogenesis Laboratory, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA.
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10
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Ferraccioli G, Romano G. Renal interstitial cells, proteinuria and progression of lupus nephritis: new frontiers for old factors. Lupus 2008; 17:533-40. [DOI: 10.1177/0961203307088002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Interstitial cells, inflammatory-immune cells, tubular cells and endothelial cells of the peritubular capillaries have arisen as possible major players of the nephron damage in lupus nephritis. Increased ICAM-1, Von Willebrand factor, soluble endothelial protein C receptors and decreased ADAMS-13 point to a diffuse vascular damage. Albuminuria elicits a rapid generation of hydrogen peroxide in proximal tubular cells along with nuclear factor-kB activation, endothelin-1 and transforming growth factor (TGF-β1) upregulation. TGF-β1 enhances epithelial-to-mesenchymal transdifferentiation. Albuminuria also enhances the expression of macrophage chemotactic protein-1 and macrophage inflammatory protein-1α, thus leading to increased interstitial inflammation. TGF-β1 and thrombospondin-1, a putative activator of TGF-β, induce apoptosis of peritubular capillaries, as well as of glomerular endothelial cells. All these events can be counteracted by hepatocyte growth factor (HGF), which is expressed by the epithelial tubular cells and stimulates the growth of epithelial cells (mitogen), enhances the motility of epithelial cells (motogen), induces renal epithelial tubule regeneration (morphogen) and enhances angiogenesis (angiogen). The balance between TGF-β1 and HGF could be a key to define the prognostic value of kidney histopathology at baseline and during follow-up, in lupus nephritis. Therapeutic strategies aiming at altering the biological balance in the patients are at hand to test and prove the experimental evidences.
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Affiliation(s)
- G Ferraccioli
- Division of Rheumatology, Catholic University of the Sacred Heart, Rome, Italy
| | - G Romano
- Nephrology Unit, University of Udine, Udine, Italy
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Vaculik C, Rüger BM, Yanagida G, Hollemann D, Soleiman A, Losert UM, Chen J, Fischer MB. Shift of C3 deposition from localization in the glomerulus into the tubulo-interstitial compartment in the absence of secreted IgM in immune complex glomerulonephritis. Clin Exp Immunol 2008; 151:146-54. [PMID: 17991287 PMCID: PMC2276927 DOI: 10.1111/j.1365-2249.2007.03534.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2007] [Indexed: 11/30/2022] Open
Abstract
The role of secretory IgM in protecting kidney tissue from immune complex glomerulonephritis induced by 4 mg horse spleen apoferritin and 0.05 mg lipopolysaccharide has been investigated in mutant mice in which B cells do not secrete IgM, but are capable of expressing surface IgM and IgD and secreting other Ig isotypes. Glomerular size, number of glomeruli per cross-section, glomerular cellularity and urine content of protein and creatinine was comparable in treated secreted IgM (sIgM)-deficient and wild-type mice. Assessment of urinary proteins by sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed a 30 kDa low molecular weight protein in treated sIgM-deficient animals only, reflecting dysfunction of proximal tubules. A shift of bound C3 from glomeruli to the tubulo-interstitial compartment in sIgM-deficient mice also suggests tubulo-interstitial damage. In contrast, local C3 synthesis within the kidney tissue did not differ between the two treated groups. Apoptosis physiologically present to maintain kidney cell homeostasis was increased slightly in treated wild-type mice. These results indicate that secretory IgM can protect the tubulo-interstitial compartment from immune complex-induced damage without having an effect on the glomerulus.
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Affiliation(s)
- C Vaculik
- Department of Transfusion Medicine, Medical University of Vienna, Vienna, Austria
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12
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Sheerin NS, Risley P, Abe K, Tang Z, Wong W, Lin T, Sacks SH. Synthesis of complement protein C3 in the kidney is an important mediator of local tissue injury. FASEB J 2007; 22:1065-72. [PMID: 18039928 DOI: 10.1096/fj.07-8719com] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Increased exposure of the tubular epithelium to filtered protein is a proposed mechanism of progressive renal failure associated with glomerular disease, but how this protein overload translates into tubular damage remains unclear. We have examined a model of adriamycin-induced proteinuria to determine the effect of locally synthesized C3, the central proinflammatory protein of the complement cascade. C3-/- kidney isografts placed in wild-type C3+/+ mice were protected from proteinuria-associated complement activation, tubular damage, and progressive renal failure despite the presence of abundant circulating C3. The quantity of urinary protein was unaffected by the absence of C3, and thus the influence of C3 was not explained by alteration in the filtered protein load. These results suggest that local synthesis of complement from renal epithelial cells is a critical mediator of tubular damage in proteinuria-associated renal disease. Our results concur with previous findings of increased synthesis of C3 in human tubular epithelium exposed to high concentrations of protein in vitro. Because progressive renal damage in humans associates with proteinuria regardless of cause, our findings have implications for the pathogenesis and treatment of renal failure from many common causes, immunological and nonimmunological.
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Affiliation(s)
- Neil S Sheerin
- King's College London, Department of Nephrology and Transplantation, Guy's Hospital, London, UK.
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13
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Thibaudin D, Thibaudin L, Berthoux P, Mariat C, Filippis JP, Laurent B, Alamartine E, Berthoux F. TNFA2 and d2 alleles of the tumor necrosis factor alpha gene polymorphism are associated with onset/occurrence of idiopathic membranous nephropathy. Kidney Int 2007; 71:431-7. [PMID: 17213876 DOI: 10.1038/sj.ki.5002054] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Idiopathic membranous nephropathy (IMN) has a strong association with the major histocompatibility complex HLA B8DR3(17)DQ2 haplotype. The tumor necrosis factor (TNF)A gene is located within the major histocompatibility complex region on chromosome 6. We have studied the influence of two functional polymorphisms; the -308 (promoter region) and the TNFd microsatellites on initiation and/or progression of IMN. This was a case-control study comparing data from 100 Caucasians patients (67 male subjects; 67%) with IMN to 232 Caucasians local controls (171 male subjects; 74%). We have analyzed genotypes and alleles distributions and the role of these polymorphisms in disease progression towards end-stage renal failure or patient death. For -308 TNFA polymorphism, distribution of genotypes was significantly different between IMN and controls (chi(2)=16.25; P=0.0003): the A2 allele frequency was 28.0% in IMN vs 15.3% in controls (chi(2)=14.57; P=0.0001). For TNFd polymorphism, alleles distribution (from d1 to d7) was also significantly different between IMN and controls (chi(2)=56.74; P<0.0001) with both diminished d3 allele frequency (chi(2)=27.30; P<0.0001; Pc=0.001) and increased d2 allele frequency (chi(2)=29.95; P<0.0001; Pc=0.001) in IMN. We could not isolate any significant and independent influence of these different genotypes on IMN disease progression. The TNFA2 and TNFd2 alleles were strongly associated with occurrence/initiation of IMN and should be considered as susceptibility genes for this disease.
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Affiliation(s)
- D Thibaudin
- Nephrology, Dialysis and Renal Transplantation Department, North University Hospital, Saint-Etienne, France
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15
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Rangan GK, Pippin JW, Coombes JD, Couser WG. C5b-9 does not mediate chronic tubulointerstitial disease in the absence of proteinuria. Kidney Int 2005; 67:492-503. [PMID: 15673297 DOI: 10.1111/j.1523-1755.2005.67106.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND In nephrotic glomerular diseases, the intratubular assembly of the membrane attack complex (C5b-9) is one of the principal mediators of chronic tubulointerstitial damage. Here, we examined whether C5b-9 has a pathogenic role in tubulointerstitial disease in the absence of proteinuria. METHODS Three pathophysiologically distinct models of nonproteinuric chronic tubulointerstitial disease were induced in Piebald-Viral-Glaxo (PVG) rats, with or without C6 deficiency (C6+ and C6): (1) unilateral ureteric obstruction (UUO, days 1, 3, 6, 14, and 21; N= 5-6/group); (2) cyclosporine (CsA) nephropathy (15 mg/kg SC daily with 0.05% sodium diet; day 14, 35 N= 9/group); and (3) streptozotocin (STZ)-induced diabetes (day 90, N= 8/group). RESULTS The peritubular deposition of C5b-9 increased in all three models. In UUO, the number of vimentin-positive tubules, interstitial volume expansion, and monocyte accumulation were similar in both the C6+ and C6- groups at all time points. There was a trend toward an earlier peak in myofibroblast accumulation in C6- rats with UUO (d3 vs. d6; P= 0.05), but this did not prevent fibrosis at later time points. In CsA nephropathy, cortical tubulointerstitial damage was also similar in both C6+ and C6- groups on day 14, despite equivalent CsA trough levels. Finally, in STZ-induced diabetes, rats did not develop proteinuria, and tubulointerstitial disease (distal tubule glycogen nephrosis, interstitial volume expansion, and tubular dilatation) was not altered by C6 deficiency. CONCLUSION These data suggest that, in contrast to proteinuric states, C5b-9 does not have a significant impact on the progression of tubulointerstitial damage in nonproteinuric chronic renal disease.
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Affiliation(s)
- Gopala K Rangan
- Division of Nephrology, University of Washington Medical Center, Seattle, Washington, USA.
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16
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Endo M, Fuke Y, Tamano M, Hidaka M, Ohsawa I, Fujita T, Ohi H. Glomerular deposition and urinary excretion of complement factor H in idiopathic membranous nephropathy. Nephron Clin Pract 2005; 97:c147-53. [PMID: 15331938 DOI: 10.1159/000079174] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2003] [Accepted: 04/02/2004] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND/AIMS The complement system plays an important role in the pathogenesis of membranous nephropathy (MN). In order to elucidate the regulatory mechanism of complement activation, we demonstrated glomerular deposition and urinary excretion of complement factor H, which controls the alternative pathway and the amplification loop at the C3 step, in patients with idiopathic MN. METHODS Renal biopsy specimens from 20 patients with idiopathic MN were studied immunohistochemically using monoclonal antibodies against complement components including factor H. SDS-PAGE and Western blotting analysis of urine samples were performed, and the urinary excretion of factor H and C5b-9 were measured by quantitative sandwich ELISA. RESULTS Intense glomerular deposition of factor H was observed with C3b.C3c and C5b-9 at an early stage of the disease. Factor H was detected in Western blots of urine samples, but factor H-like protein 1 (FHL-1) was not. The mean level of urinary factor H was elevated (86.30 +/- 21.93 U/mg urinary creatinine) in comparison to that of normal controls (4.76 +/- 1.03 U/mg urinary creatinine). Urinary factor H level exhibited no correlation with clinical parameters; however, a negative correlation was found between urinary C5b-9/factor H and creatinine clearance (r = 0.662, p < 0.01). CONCLUSION The source of glomerular and urinary factor H is supposedly a 150-kD protein. There was no evidence to suggest that FHL-1 is synthesized at the site of inflammation. The urinary C5b-9 to urinary factor H ratio is indicative of the degree of ongoing complement activation in the glomeruli and complement-mediated renal injury. These findings suggest that factor H contributes to the control mechanism of in situ complement activation and prevents renal damage in idiopathic MN.
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Affiliation(s)
- Morito Endo
- Division of Nephrology, Internal Medicine II, Nihon University School of Medicine, Tokyo, Japan.
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Castellano G, Cappiello V, Fiore N, Pontrelli P, Gesualdo L, Schena FP, Montinaro V. CD40 ligand increases complement C3 secretion by proximal tubular epithelial cells. J Am Soc Nephrol 2005; 16:2003-11. [PMID: 15872081 DOI: 10.1681/asn.2002120972] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Interstitial leukocyte infiltration is a major finding in tubulointerstitial damage (TID). Infiltrating lymphocytes interact with proximal tubular epithelial cells (PTEC) by means of secreted soluble factors and/or cell contact mechanisms. CD40 expressed onto PTEC can be engaged by CD40L present on T cells. PTEC are able to locally secrete complement C3, which may most likely promote TID. The aim of the study was to investigate the putative action of CD40 ligation on enhancement of C3 secretion by PTEC. Primary human PTEC and stabilized HK-2 cells were used in culture experiments. Cells were stimulated by soluble factors IL-1beta, IFN-gamma, and/or CD40L-expressing murine fibroblast L cells. Analysis of C3 gene expression was evaluated by reverse-transcription PCR and Northern blot. Secreted C3 was assayed by ELISA and a functional hemolytic test on supernatants. Intracellular events were explored by the NF-kappaB-specific inhibitor caffeic acid phenetyl ester (CAPE). Among soluble factors, IL-1beta and IFN-gamma increased C3 gene expression and secretion (two-fold to three-fold versus basal) on both HK-2 and PTEC. CD40 engagement by CD40L upregulated HK-2 C3 secretion by four-fold. IL-1beta did not further increase CD40-induced C3 secretion, whereas IFN-gamma associated with CD40L was the strongest stimulus (30-fold increase). Inhibition of NF-kappaB offset CD40L-induced C3 secretion by 70%. CD40 ligation is able to enhance C3 secretion by PTEC. This cell contact mechanism is in synergism with a T cell-derived soluble factor (IFN-gamma). C3 secretion induced by CD40L may represent a mechanism of amplification of TID associated with lymphocyte infiltration.
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Affiliation(s)
- Giuseppe Castellano
- Division of Nephrology, Department of Emergency and Organ Transplantation, University of Bari, Azienda Ospedaliera Policlinico, Piazza G. Cesare 11, 70124 Bari, Italy
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Stehberger PA, Schulz N, Finberg KE, Karet FE, Giebisch G, Lifton RP, Geibel JP, Wagner CA. Localization and Regulation of the ATP6V0A4 (a4) Vacuolar H+-ATPase Subunit Defective in an Inherited Form of Distal Renal Tubular Acidosis. J Am Soc Nephrol 2003; 14:3027-38. [PMID: 14638902 DOI: 10.1097/01.asn.0000099375.74789.ab] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
ABSTRACT. Vacuolar-type H+-ATPases (V-H+-ATPases) are the major H+-secreting protein in the distal portion of the nephron and are involved in net H+secretion (bicarbonate generation) or H+reabsorption (net bicarbonate secretion). In addition, V-H+-ATPases are involved in HCO3−reabsorption in the proximal tubule and distal tubule. V-H+-ATPases consist of at least 13 subunits, the functions of which have not all been elucidated. Mutations in the accessory ATP6V0A4 (a4 isoform) subunit have recently been shown to cause an inherited form of distal renal tubular acidosis in humans. Here, the localization of this subunit in human and mouse kidney was studied and the regulation of expression and localization of this subunit in mouse kidney in response to acid-base and electrolyte intake was investigated. Reverse transcription-PCR on dissected mouse nephron segments amplified a4-specific transcripts in proximal tubule, loop of Henle, distal convoluted tubule, and cortical and medullary collecting duct. a4 protein was localized by immunohistochemistry to the apical compartment of the proximal tubule (S1/S2 segment), the loop of Henle, the intercalated cells of the distal convoluted tubule, the connecting segment, and all intercalated cells of the entire collecting duct in human and mouse kidney. All types of intercalated cells expressed a4. NH4Cl or NaHCO3loading for 24 h, 48 h, or 7 d as well as K+depletion for 7 and 14 d had no influence on a4 protein expression levels in either cortex or medulla as determined by Western blotting. Immunohistochemistry, however, demonstrated a subcellular redistribution of a4 in response to the different stimuli. NH4Cl and K+depletion led to a pronounced apical staining in the connecting segment, cortical collecting duct, and outer medullary collecting duct, whereas NaHCO3loading caused a stronger bipolar staining in the cortical collecting duct. Taken together, these results demonstrate a4 expression in the proximal tubule, loop of Henle, distal tubule, and collecting duct and suggest that under conditions in which increased V-H+-ATPase activity is required, a4 is regulated by trafficking but not protein expression. This may allow for the rapid adaptation of V-H+-ATPase activity to altered acid-base intake to achieve systemic pH homeostasis. The significance of a4 expression in the proximal tubule in the context of distal renal tubular acidosis will require further clarification.
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Affiliation(s)
- Paul A Stehberger
- Departments of Cellular and Molecular Physiology, Genetics, and Surgery, Yale University School of Medicine, New Haven, Connecticut, USA
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Hsu SIH, Couser WG. Chronic progression of tubulointerstitial damage in proteinuric renal disease is mediated by complement activation: a therapeutic role for complement inhibitors? J Am Soc Nephrol 2003; 14:S186-91. [PMID: 12819326 DOI: 10.1097/01.asn.0000070032.58017.20] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The mechanisms by which increased urinary protein concentrations lead to nephrotoxic injury are certain to be multifactorial and involve complex interactions between numerous pathways of cellular damage mediated by both cellular and humoral pathways. These may include a major role for the podocyte in glomerular diseases leading to chronic renal failure, the loss of microvascular endothelium, the albumin-induced upregulation of renal cytokines and growth factors that promote tubulointerstitial injury by inflammation and fibrogenesis, and the role of complement-mediated tubulointerstitial injury due to proteinuria. This review will focus on the last mechanism, and emphasize recent studies implicating a primary role for activation of complement in proteinuric urine as the principal mediator of tubulointerstitial damage and progressive renal disease in various experimental animal models of nephrosis. It will be our contention that intraluminal activation of the terminal complement cascade leading to the formation of the C5b-9 membrane attack complex is the principal mediator of chronic progressive interstitial damage and progressive renal failure irrespective of the type of primary glomerular injury. This paradigm has important implications for the potential therapeutic role of complement inhibitors that are currently being developed.
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Affiliation(s)
- Stephen I-Hong Hsu
- Institute of Prevention and Research, National Kidney Foundation of Singapore.
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Branten AJ, Kock-Jansen M, Klasen IS, Wetzels JF. Urinary excretion of complement C3d in patients with renal diseases. Eur J Clin Invest 2003; 33:449-56. [PMID: 12795640 DOI: 10.1046/j.1365-2362.2003.01153.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Complement-mediated tubular injury may play an important role in the progression of renal diseases. C3d is a presumed marker of complement activation. Its precursor C3dg has been detected in the urine of patients with membranous nephropathy. However, little is known of the renal handling of C3d or its excretion in other renal diseases. METHODS We measured the urinary excretion of albumin, IgG, beta2-microglobulin (beta2m), and of complement C3d in patients with tubulo-interstitial nephritis (TIN; n= 8), in patients with membranous nephropathy (n = 35) and in patients with nonmembranous glomerular diseases (23 nonproliferative and 21 proliferative). Fractional excretions (FE) were calculated using creatinine clearance as marker of GFR. RESULTS C3d was not measurable in the urine of the healthy controls, but was detectable in seven out of eight of the TIN patients (median excretion 0.11 mU min-1, range 0.006-2.4 mU min-1). In these patients the urinary excretion of beta2m was clearly elevated (median 26.6 micro g min-1, range 1.0-103 micro g min-1). The FE of C3d correlated with the FE of beta2microglobulin (r = 0.83, P = 0.01), and their ratio amounted to 0.03 (range 0.003-0.06), a value in agreement with the expected sieving coefficient. Urine C3d was detectable in all but three of the patients with glomerular diseases (median excretion 0.36 mU min-1, range 0.004-7.9 mU min-1); C3d-excretion did not differ between the three subgroups of patients with glomerular diseases. FEC3d correlated with FEIgG (r = 0.88, P < 0.01). The ratio FEC3d/FEbeta2m was 0.78 (range 0.04-9.99). Selected patients with membranous nephropathy were re-analyzed after (partial) remission of proteinuria. Reduction of proteinuria resulted in a decrease of C3d excretion. CONCLUSION Urinary excretion of C3d is elevated in patients with TIN, most likely as a mere consequence of decreased tubular reabsorption. In patients with glomerular diseases urinary excretion of C3d is increased and related to proteinuria, independent of the underlying glomerular disease. In these patients there is evidence of increased local formation of C3d.
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Affiliation(s)
- A J Branten
- University Medical Center Nijmegen, Nijmegen, the Netherlands.
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Abstract
During the past decade, research has shown that the kidney has the capacity to synthesize most of the activation pathway components of the complement cascade. As well as implying physiological roles in local clearance of immune complexes and defense against invasive organisms, an increasing amount of evidence indicates that the intrarenal synthesis of complement makes an important contribution in the pathogenesis of renal injury. Here we review this evidence and present a case for more definitive investigation of these functions.
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Affiliation(s)
- W Zhou
- Department of Nephrology and Transplantation, Guy's Hospital, London, England, United Kingdom
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