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Zhang HJ, Ding PP, Zhang XS, Wang XC, Sun DW, Bu QA, Li XQ. MAC mediates mammary duct epithelial cell injury in plasma cell mastitis and granulomatous mastitis. Int Immunopharmacol 2022; 113:109303. [DOI: 10.1016/j.intimp.2022.109303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 08/01/2022] [Accepted: 09/28/2022] [Indexed: 11/05/2022]
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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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Wang X, Liu J, Tian R, Zheng B, Li C, Huang L, Lu Z, Zhang J, Mao W, Liu B, Bao K, Xu P. Sanqi Oral Solution Mitigates Proteinuria in Rat Passive Heymann Nephritis and Blocks Podocyte Apoptosis via Nrf2/HO-1 Pathway. Front Pharmacol 2021; 12:727874. [PMID: 34867334 PMCID: PMC8640486 DOI: 10.3389/fphar.2021.727874] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 10/25/2021] [Indexed: 12/29/2022] Open
Abstract
Idiopathic membranous nephropathy (IMN) is the most common pathological type in adult nephrotic syndrome where podocyte apoptosis was found to mediate the development of proteinuria. Sanqi oral solution (SQ), an effective Chinese herbal preparation clinically used in treatment of IMN for decades, plays an important role in reducing proteinuria, but the underlying mechanisms have not been fully elucidated yet. The current study tested the hypothesis that SQ directly lessens proteinuria in IMN by reducing podocyte apoptosis. To investigate the effects of SQ, we established the experimental passive Heymann nephritis (PHN) rat model induced by anti-Fx1A antiserum in vivo and doxorubicin hydrochloride (ADR)-injured apoptotic podocyte model in vitro. SQ intervention dramatically reduced the level of proteinuria, together with the rat anti-rabbit IgG antibodies, complement C3, and C5b-9 deposition in glomerulus of PHN rats, accompanied by an elevation of serum albumin. Protein expression of synaptopodin, marker of podocyte injury, restored after SQ administration, whereas the electron microscopic analysis indicated that fusion of foot processes, and the pachynsis of glomerular basement membrane was markedly diminished. Further studies showed that SQ treatment could significantly inhibit podocyte apoptosis in PHN rats and ADR-injured podocytes, and protein levels of Cleaved Caspase-3 or the ratio of Bax/Bcl-2 were significantly decreased with SQ treatment in vivo or in vitro. Moreover, we found that the nuclear factor erythroid 2–related factor-2/heme oxygenase 1 (Nrf2/HO-1) pathway mediated the anti-apoptosis effective of SQ in podocyte. Thus, SQ mitigates podocyte apoptosis and proteinuria in PHN rats via the Nrf2/HO-1 pathway.
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Affiliation(s)
- Xiaowan Wang
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China.,Guangdong Provincial Key Laboratory of Chinese Medicine for Prevention and Treatment of Refractory Chronic Diseases, Guangzhou, China.,Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China
| | - Jinchu Liu
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Ruimin Tian
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China.,Guangdong Provincial Key Laboratory of Chinese Medicine for Prevention and Treatment of Refractory Chronic Diseases, Guangzhou, China.,Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China
| | - Bidan Zheng
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Chuang Li
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China.,Guangdong Provincial Key Laboratory of Chinese Medicine for Prevention and Treatment of Refractory Chronic Diseases, Guangzhou, China.,Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China
| | - Lihua Huang
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China.,Guangdong Provincial Key Laboratory of Chinese Medicine for Prevention and Treatment of Refractory Chronic Diseases, Guangzhou, China.,Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China
| | - Zhisheng Lu
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Jing Zhang
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China
| | - Wei Mao
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China.,Guangdong Provincial Key Laboratory of Chinese Medicine for Prevention and Treatment of Refractory Chronic Diseases, Guangzhou, China.,Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China
| | - Bo Liu
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China.,Guangzhou Key Laboratory of Chirality Research on Active Components of Traditional Chinese Medicine, Guangzhou, China
| | - Kun Bao
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China.,Guangdong Provincial Key Laboratory of Chinese Medicine for Prevention and Treatment of Refractory Chronic Diseases, Guangzhou, China.,Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China
| | - Peng Xu
- State Key Laboratory of Dampness Syndrome of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China.,Guangdong Provincial Key Laboratory of Chinese Medicine for Prevention and Treatment of Refractory Chronic Diseases, Guangzhou, China.,Guangdong Provincial Academy of Chinese Medical Sciences, Guangzhou, China
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Detsika MG, Goudevenou K, Geurts AM, Gakiopoulou H, Grapsa E, Lianos EA. Generation of a novel decay accelerating factor (DAF) knock-out rat model using clustered regularly-interspaced short palindromic repeats, (CRISPR)/associated protein 9 (Cas9), genome editing. Transgenic Res 2021; 30:11-21. [PMID: 33387103 DOI: 10.1007/s11248-020-00222-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 11/13/2020] [Indexed: 11/30/2022]
Abstract
Decay accelerating factor (DAF), a key complement activation control protein, is a 70 kDa membrane bound glycoprotein which controls extent of formation of the C3 and C5 convertases by accelerating their decay. Using clustered regularly-interspaced short palindromic repeats, (CRISPR)/associated protein 9 (Cas9) genome editing we generated a novel DAF deficient (Daf-/-) rat model. The present study describes the renal and extrarenal phenotype of this model and assesses renal response to complement-dependent injury induced by administration of a complement-fixing antibody (anti-Fx1A) against the glomerular epithelial cell (podocyte). Rats generated were healthy, viable and able to reproduce normally. Complete absence of DAF was documented in renal as well as extra-renal tissues at both protein and mRNA level compared to Daf+/+ rats. Renal histology in Daf-/- rats showed no differences regarding glomerular or tubulointerstitial pathology compared to Daf+/+ rats. Moreover, there was no difference in urine protein excretion (ratio of urine albumin to creatinine) or in serum creatinine and urea levels. In Daf-/- rats, proteinuria was significantly increased following binding of anti-Fx1A antibody to podocytes while increased C3b deposition was observed. The DAF knock-out rat model developed validates the role of this complement cascade regulator in immune-mediated podocyte injury. Given the increasing role of dysregulated complement activation in various forms of kidney disease and the fact that the rat is the preferred animal for renal pathophysiology studies, the rat DAF deficient model may serve as a useful tool to study the role of this complement activation regulator in complement-dependent forms of kidney injury.
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Affiliation(s)
- Maria G Detsika
- 1st Department of Critical Care Medicine and Pulmonary Services, School of Medicine, Evangelismos Hospital, G.P. Livanos and M. Simou Laboratories, National and Kapodistrian University of Athens, 3 Ploutarchou Street, 10675, Athens, Greece.
| | - K Goudevenou
- 1st Department of Critical Care Medicine and Pulmonary Services, School of Medicine, Evangelismos Hospital, G.P. Livanos and M. Simou Laboratories, National and Kapodistrian University of Athens, 3 Ploutarchou Street, 10675, Athens, Greece
| | - A M Geurts
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - H Gakiopoulou
- Department of Pathology, University of Athens School of Medicine, Athens, Greece
| | - E Grapsa
- Department of Nephrology, School of Medicine, Aretaieion University Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Elias A Lianos
- Veterans Affairs Medical Center and Virginia Tech. Carilion School of Medicine, 1970 Roanoke Blvd., Salem, VA, 24153, USA
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Abstract
Activation of the complement system is tightly regulated by plasma and cell-associated complement regulatory proteins (CRPs), such as factor H (fH), decay-accelerating factor, and membrane cofactor protein. Animal models of disease have provided considerable insights into the important roles for CRPs in the kidney. Mice deficient in fH have excessive fluid phase C3 activation and inactivation, leading to deposition of inactivated C3b in glomerular capillary walls (GCW), comparable with dense deposit disease. In contrast, when fH lacks C-terminal surface targeting regions, local activation on the GCW leads to a disease reminiscent of thrombotic microangiopathy. The uniquely rodent protein, CR1-related y (Crry), has features analogous to human membrane cofactor protein. Defective Crry leads to unrestricted alternative pathway activation in the tubulointerstitium, resulting in pathologic features ranging from thrombotic microangiopathy (TMA), acute kidney injury, and tubulointerstitium nephritis. In the presence of initiators of the classic or lectin pathways, commonly in the form of immune complexes in human glomerular diseases, complement regulation is stressed, with the potential for recruitment of the spontaneously active alternative pathway. The threshold for this activation is set by CRPs; pathology is more likely when complement regulation is defective. Within the endocapillary region of the GCW, fH is key, while decay-accelerating factor and Crry are protective on mesangial cells and podocytes. Arguably, acquired alterations in these CRPs is a more common event, extending from pathologic states of cellular injury or production of inhibitory antibodies, to physiological fine tuning of the adaptive immune response.
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A compendium of urinary biomarkers indicative of glomerular podocytopathy. PATHOLOGY RESEARCH INTERNATIONAL 2013; 2013:782395. [PMID: 24327929 PMCID: PMC3845336 DOI: 10.1155/2013/782395] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 09/10/2013] [Indexed: 12/18/2022]
Abstract
It is well known that glomerular podocyte injury and loss are present in numerous nephropathies and that the pathophysiologic consecution of disease hinges upon the fate of the podocyte. While multiple factors play a hand in glomerulopathy progression, basic logic lends that if one monitors the podocyte's status, that may reflect the status of disease. Recent investigations have focused on what one can elucidate from the noninvasive collection of urine, and have proven that certain, specific biomarkers of podocytes can be readily identified via varying techniques. This paper has brought together all described urinary biomarkers of podocyte injury and is made to provide a concise summary of their utility and testing in laboratory and clinical theatres. While promising in the potential that they hold as tools for clinicians and investigators, the described biomarkers require further comprehensive vetting in the form of larger clinical trials and studies that would give their value true weight. These urinary biomarkers are put forth as novel indicators of glomerular disease presence, disease progression, and therapeutic efficacy that in some cases may be more advantageous than the established parameters/measures currently used in practice.
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7
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Eadon MT, Hack BK, Alexander JJ, Xu C, Dolan ME, Cunningham PN. Cell cycle arrest in a model of colistin nephrotoxicity. Physiol Genomics 2013; 45:877-88. [PMID: 23922129 DOI: 10.1152/physiolgenomics.00076.2013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Colistin (polymixin E) is an antibiotic prescribed with resurging frequency for multidrug resistant gram negative bacterial infections. It is associated with nephrotoxicity in humans in up to 55% of cases. Little is known regarding genes involved in colistin nephrotoxicity. A murine model of colistin-mediated kidney injury was developed. C57/BL6 mice were administered saline or colistin at a dose of 16 mg/kg/day in 2 divided intraperitoneal doses and killed after either 3 or 15 days of colistin. After 15 days, mice exposed to colistin had elevated blood urea nitrogen (BUN), creatinine, and pathologic evidence of acute tubular necrosis and apoptosis. After 3 days, mice had neither BUN elevation nor substantial pathologic injury; however, urinary neutrophil gelatinase-associated lipocalin was elevated (P = 0.017). An Illumina gene expression array was performed on kidney RNA harvested 72 h after first colistin dose to identify differentially expressed genes early in drug treatment. Array data revealed 21 differentially expressed genes (false discovery rate < 0.1) between control and colistin-exposed mice, including LGALS3 and CCNB1. The gene signature was significantly enriched for genes involved in cell cycle proliferation. RT-PCR, immunoblot, and immunostaining validated the relevance of key genes and proteins. This murine model offers insights into the potential mechanism of colistin-mediated nephrotoxicity. Further studies will determine whether the identified genes play a causative or protective role in colistin-induced nephrotoxicity.
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Affiliation(s)
- Michael T Eadon
- Divisions of Nephrology and Clinical Pharmacology, Indiana University, Indianapolis, Indiana
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8
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Huang Z, Hong Q, Xue P, Paul G, Feng Z, Wang L, Mei Y, Wu L, Chen X, Wu D. A proteome-wide screen identifies valosin-containing protein as an essential regulator of podocyte endoplasmic reticulum stress. CHINESE SCIENCE BULLETIN-CHINESE 2012. [DOI: 10.1007/s11434-012-5250-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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9
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Autophagy can repair endoplasmic reticulum stress damage of the passive Heymann nephritis model as revealed by proteomics analysis. J Proteomics 2012; 75:3866-76. [DOI: 10.1016/j.jprot.2012.04.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Revised: 03/16/2012] [Accepted: 04/12/2012] [Indexed: 12/22/2022]
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10
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Rodriguez EF, Cosio FG, Nasr SH, Sethi S, Fidler ME, Stegall MD, Grande JP, Fervenza FC, Cornell LD. The pathology and clinical features of early recurrent membranous glomerulonephritis. Am J Transplant 2012; 12:1029-38. [PMID: 22233329 DOI: 10.1111/j.1600-6143.2011.03903.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We assessed the earliest manifestations of recurrent membranous glomerulonephritis (MGN) in renal allografts. Clinical, laboratory and pathologic data were reviewed in 21 patients at the initial biopsy within 4 months post-transplant with evidence of MGN and on follow-up biopsies, compared to a biopsy control group of eight transplants without recurrent MGN. The mean time of first biopsy with pathologic changes was 2.7 months. In each earliest biopsy, immunofluorescence (IF) showed granular glomerular basement membrane (GBM) staining for C4d, IgG, kappa and lambda. IF for C3 was negative or showed trace staining in 16/21. On each MGN biopsy positive by IF, 14/19 showed absence of deposits or rare tiny subepithelial deposits by electron microscopy (EM). At the earliest biopsy, the mean proteinuria was 1.1 g/day; 16 patients had <1 g/day proteinuria. Follow-up was available in all patients (mean 35 months posttransplant). A total of 13 patients developed >1 g/day proteinuria; 12 were treated with: rituximab (n = 8), ACEI and increased prednisone dose (n = 2), ACEI or ARB only (n = 2). All patients showed reduction in proteinuria after treatment. A total of 11/16 patients showed progression of disease by EM on follow-up biopsy. Recognition of early allograft biopsy features aids in diagnosis of recurrent MGN before patients develop significant proteinuria.
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Affiliation(s)
- E F Rodriguez
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
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Glassock RJ. The Pathogenesis of Idiopathic Membranous Nephropathy: A 50-Year Odyssey. Am J Kidney Dis 2010; 56:157-67. [PMID: 20378220 DOI: 10.1053/j.ajkd.2010.01.008] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Accepted: 01/13/2010] [Indexed: 11/11/2022]
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12
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Pippin JW, Brinkkoetter PT, Cormack-Aboud FC, Durvasula RV, Hauser PV, Kowalewska J, Krofft RD, Logar CM, Marshall CB, Ohse T, Shankland SJ. Inducible rodent models of acquired podocyte diseases. Am J Physiol Renal Physiol 2009; 296:F213-29. [DOI: 10.1152/ajprenal.90421.2008] [Citation(s) in RCA: 198] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Glomerular diseases remain the leading cause of chronic and end-stage kidney disease. Significant advances in our understanding of human glomerular diseases have been enabled by the development and better characterization of animal models. Diseases of the glomerular epithelial cells (podocytes) account for the majority of proteinuric diseases. Rodents have been extensively used experimentally to better define mechanisms of disease induction and progression, as well as to identify potential targets and therapies. The development of podocyte-specific genetically modified mice has energized the research field to better understand which animal models are appropriate to study acquired podocyte diseases. In this review we discuss inducible experimental models of acquired nondiabetic podocyte diseases in rodents, namely, passive Heymann nephritis, puromycin aminonucleoside nephrosis, adriamycin nephrosis, liopolysaccharide, crescentic glomerulonephritis, and protein overload nephropathy models. Details are given on the model backgrounds, how to induce each model, the interpretations of the data, and the benefits and shortcomings of each. Genetic rodent models of podocyte injury are excluded.
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Bao L, Haas M, Minto AW, Quigg RJ. Decay-accelerating factor but not CD59 limits experimental immune-complex glomerulonephritis. J Transl Med 2007; 87:357-64. [PMID: 17259999 DOI: 10.1038/labinvest.3700522] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The complex balance between the pro-activating and regulatory influences of the complement system can affect the pathogenesis of immune complex-mediated glomerulonephritis (ICGN). Key complement regulatory proteins include decay accelerating factor (DAF) and CD59, which inhibit C3 activation and C5b-9 generation, respectively. Both are glycosylphosphatidylinositol-linked cell membrane proteins, which are widely distributed in humans and mice. Chronic serum sickness induced by daily immunization with horse spleen apoferritin over 6 weeks was used to induce ICGN in DAF-, CD59- and DAF/CD59-deficient mice, with wild-type littermate mice serving as controls. Both DAF and DAF/CD59-deficient mice had an increased incidence of GN relative to wild-type controls associated with significantly increased glomerular C3 deposition. Disease expression in CD59-deficient mice was no different than wild-type controls. DAF- and DAF/CD59-deficient mice also had increased monocyte chemoattractant protein-1 mRNA expression and glomerular infiltration with CD45(+) leukocytes. Our findings suggest that activation of C3 is strongly associated with experimental ICGN while downstream formation of C5b-9 is of lesser pathogenic importance in this model.
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Affiliation(s)
- Lihua Bao
- Section of Nephrology, The University of Chicago, Chicago, IL 60637, USA.
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14
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Moll S, Lange S, Mihatsch MJ, Dragic Z, Schifferli JA, Inal JM. CRIT is expressed on podocytes in normal human kidney and upregulated in membranous nephropathy. Kidney Int 2006; 69:1961-8. [PMID: 16598195 DOI: 10.1038/sj.ki.5000379] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Complement C2 receptor inhibitor trispanning (CRIT) is a novel human complement regulatory cell surface receptor. It binds the human complement protein C2 and blocks the classical pathway of complement activation, thus protecting the cell against complement attack. CRIT expression in the kidney was analyzed by immunohistochemistry and in situ hybridization. Normal kidney and renal biopsies of patients with different nephropathies were studied. In glomeruli, CRIT protein was expressed only in podocytes. CRIT was also detected in endothelial cells of arterioles and arteries, but not of veins and peritubular and glomerular capillaries. A homogeneous and marked upregulation of CRIT was observed in podocytes in membranous nephropathy (MN). In focal and segmental glomerulosclerosis (FSGS) and minimal change disease, CRIT was downregulated in glomeruli with a loss of the staining in sclerotic lesions of FSGS. No specific changes were observed in the other nephropathies studied. However, podocytes showed in all pathologies a redistribution of CRIT in the cell bodies of 'activated' podocytes. The intensity of mRNA transcription correlated directly with the protein staining in the normal kidney and in MN. These data indicate that CRIT is expressed in the normal human kidney essentially by glomerular podocytes and arterial endothelial cells. The podocyte CRIT expression is upregulated in MN, which is in strong contrast with the known loss of podocyte complement receptor 1. CRIT might represent the last line of defense against complement aggression in MN, and the upregulation of CRIT in 'activated' podocytes might represent a similar self-defense mechanism.
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Affiliation(s)
- S Moll
- Clinical Pathology, University Hospitals of Geneva and Lausanne, Geneva, Switzerland
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15
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Wang Y, He Q, Qin H, Xu J, Tong J, Gao L, Xu J. The complement C5b-9 complexes induced injury of glomerular mesangial cells in rats with Thy-1 nephritis by increasing nitric oxide synthesis. Life Sci 2006; 79:182-92. [PMID: 16458938 DOI: 10.1016/j.lfs.2005.12.053] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2005] [Revised: 12/15/2005] [Accepted: 12/22/2005] [Indexed: 10/25/2022]
Abstract
Thy-1 nephritis (Thy-1 N), namely, anti-Thy-1 or anti-thymocyte serum (ATS) induced nephritis (ATSN), is a typical model of human mesangioproliferative glomerulonephritis. The pathologic changes of glomerular mesangial cells (GMCs) in Thy-1 N are complement-dependent, especially C5b-9 complexes, but the role of C5b-9 in the mechanism of Thy-1 N has not been defined. Because previous studies have demonstrated that sublytic C5b-9 can increase production of several inflammatory mediators from resident glomerular cells, we utilized the isolated human membrane-bound C5b-9 complexes to stimulate the cultured rat GMCs and examined whether the GMCs can also induce the synthesis of nitric oxide (NO) in vitro. Simultaneously, the effects of antiserum against rat C5b-9 and NG-monomethyl-L-arginine (L-NMMA, NO inhibitor), including interfering with the formation of C5b-9, reducing NO production and GMCs injury were observed. The results showed that sublytic C5b-9 can increase synthesis of inducible NO from the stimulated GMCs, and that the anti-C5b-9 antiserum can obviously inhibit the pathologic changes in Thy-1 N, while L-NMMA can decrease the GMCs damage although the effect is not so significant as that of the anti-C5b-9 antiserum. These findings indicate that the synthesis of NO by GMCs can be promoted by sublytic C5b-9, and that lesions of GMCs in rats with Thy-1 N are prevented by either inhibiting C5b-9 formation or NO elevation in advance. The pathologic changes of GMCs in Thy-1 N are indeed complement C5b-9-dependent, and the glomerular injury can be mediated in part through elevation of NO from the GMCs after the sublytic C5b-9 stimulation.
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Affiliation(s)
- Yingwei Wang
- Department of Immunology, Nanjing Medical University, Nanjing Hanzhong Road 140 #, Jiangsu Province, 210029, PR China.
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16
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Nangaku M, Couser WG. Mechanisms of immune-deposit formation and the mediation of immune renal injury. Clin Exp Nephrol 2005; 9:183-91. [PMID: 16189625 DOI: 10.1007/s10157-005-0357-8] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Accepted: 03/17/2005] [Indexed: 10/25/2022]
Abstract
The passive trapping of preformed immune complexes is responsible for some forms of glomerulonephritis that are associated with mesangial or subendothelial deposits. The biochemical characteristics of circulating antigens play important roles in determining the biologic activity of immune complexes in these cases. Examples of circulating immune complex diseases include the classic acute and chronic serum sickness models in rabbits, and human lupus nephritis. Immune deposits also form "in situ". In situ immune deposit formation may occur at subepithelial, subendothelial, and mesangial sites. In situ immune-complex formation has been most frequently studied in the Heymann nephritis models of membranous nephropathy with subepithelial immune deposits. While the autoantigenic target in Heymann nephritis has been identified as megalin, the pathogenic antigenic target in human membranous nephropathy had been unknown until the recent identification of neutral endopeptidase as one target. It is likely that there is no universal antigen in human membranous nephropathy. Immune complexes can damage glomerular structures by attracting circulating inflammatory cells or activating resident glomerular cells to release vasoactive substances, cytokines, and activators of coagulation. However, the principal mediator of immune complex-mediated glomerular injury is the complement system, especially C5b-9 membrane attack complex formation. C5b-9 inserts in sublytic quantities into the membranes of glomerular cells, where it produces cell activation, converting normal cells into resident inflammatory effector cells that cause injury. Excessive activation of the complement system is normally prevented by a series of circulating and cell-bound complement regulatory proteins. Genetic deficiencies or mutations of these proteins can lead to the spontaneous development of glomerular disease. The identification of specific antigens in human disease may lead to the development of fundamental therapies. Particularly promising future therapeutic approaches include selective immunosuppression and interference in complement activation and C5b-9-mediated cell injury.
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Affiliation(s)
- Masaomi Nangaku
- Division of Nephrology and Endocrinology, University of Tokyo School of Medicine, 7-3-1 Bunkyo-ku, Tokyo, 113-8655, Japan.
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Abstract
Membranous nephropathy (MN) is a common cause of nephrotic syndrome in adults. Active and passive Heymann nephritis (HN) in rats are valuable experimental models because their features so closely resemble human MN. In HN, subepithelial immune deposits form in situ as a result of circulating antibodies. Complement activation leads to assembly of C5b-9 on glomerular epithelial cell (GEC) plasma membranes and is essential for sublethal GEC injury and the onset of proteinuria. This review revisits HN and focuses on areas of substantial progress in recent years. The response of the GEC to sublethal C5b-9 attack is not simply due to disruption of the plasma membrane but is due to the activation of specific signaling pathways. These include activation of protein kinases, phospholipases, cyclooxygenases, transcription factors, growth factors, NADPH oxidase, stress proteins, proteinases, and others. Ultimately, these signals impact on cell metabolic pathways and the structure/function of lipids and key proteins in the cytoskeleton and slit-diaphragm. Some signals affect GEC adversely. Thus C5b-9 induces partial dissolution of the actin cytoskeleton. There is a decline in nephrin expression, reduction in F-actin-bound nephrin, and loss of slit-diaphragm integrity. Other signals, such as endoplasmic reticulum stress, may limit complement-induced injury, or promote recovery. The extent of complement activation and GEC injury is dependent, in part, on complement-regulatory proteins, which act at early or late steps within the complement cascade. Identification of key steps in complement activation, the cellular signaling pathways, and the targets will facilitate therapeutic intervention in reversing GEC injury in human MN.
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Affiliation(s)
- Andrey V Cybulsky
- Renal Section, EBRC 504, Boston Univ. Medical Ctr., 650 Albany St., Boston, MA 02118, USA
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Cunningham PN, Quigg RJ. Contrasting roles of complement activation and its regulation in membranous nephropathy. J Am Soc Nephrol 2005; 16:1214-22. [PMID: 15800113 DOI: 10.1681/asn.2005010096] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The complement system is involved in defense against microorganisms, the processing of immune complexes and apoptotic debris, and the development of an appropriate immune response. Along with these physiologic effects, complement activation has the potential to result in tissue pathology. To limit this, various complement regulatory proteins (CRP) are present on host cells, including the glomerular podocyte. Experimental data from the Heymann nephritis (HN) rat model of human membranous nephropathy (MN) have shown that IgG antibodies in subepithelial immune deposits initiate complement activation and C5b-9-mediated damage of the overlying podocyte. Although IgG can activate the classical pathway, there also is evidence that alternative pathway activation occurs in MN, which could occur because of absent, dysfunctional, or inhibited podocyte CRP. Related to this are experimental data in HN showing the presence of antibodies that bind and inhibit podocyte CRP; although such antibodies have not been documented in human MN, a decrease in CR1 quantity on the podocyte has been observed. A s a result of a relative lack of CRP and the exposure of activating complement proteins to tubular cells, alternative complement pathway activation and C5b-9-mediated tubular injury can occur in MN and other proteinuric diseases. Overall, in a disease such as MN, the balance between complement regulation and activation is tipped toward its being activated. Therefore, a number of therapeutic approaches have been developed to counteract this, including recombinant forms of endogenous CRP and complement-inhibitory monoclonal antibodies. There is good reason to be optimistic that approaches to block complement activation will become viable therapy for human MN in the future.
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Affiliation(s)
- Patrick N Cunningham
- Section of Nephrology, The University of Chicago, AMB-S523, MC 5100, 5841 South Maryland Avenue, Chicago, IL 60637, USA
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Ren G, Doshi M, Hack BK, Alexander JJ, Quigg RJ. Rat glomerular epithelial cells produce and bear factor H on their surface that is up-regulated under complement attack. Kidney Int 2003; 64:914-22. [PMID: 12911541 DOI: 10.1046/j.1523-1755.2003.00188.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Factor H is a potent complement inhibitory molecule that is primarily produced by the liver and appears in plasma as a soluble protein. Yet there is evidence that other cells, including those in the kidney, can produce factor H, and that it can be cell-associated as well as present as a plasma protein. Here we studied factor H in rat glomerular epithelial cells (GEC). METHODS A polyclonal antibody to factor H was used to identify factor H protein. A polymerase chain reaction (PCR)-based strategy was utilized to clone the full-length cDNA of GEC factor H. The relative quantity of factor H mRNA was measured by quantitative reverse transcription (RT)-PCR in cultured GEC exposed to complement activation and in the passive Heymann nephritis (PHN) model of membranous nephropathy. RESULTS By immunofluorescence microscopy, factor H protein was present on the plasma membranes of cultured GEC. Based upon Western blot studies, this appeared to be the full-length 150 kD factor H protein. Factor H cDNA cloned from GEC was identical to the newly deposited sequence for rat liver factor H cDNA. In cultured GEC in which complement was activated, factor H mRNA increased over time. Similarly, in the PHN model in which complement was activated on GEC in vivo, factor H mRNA and protein also increased over time. CONCLUSION Cultured GEC and glomeruli express factor H mRNA and protein. As modeled both in vitro and in vivo in the rat, factor H is up-regulated in membranous nephropathy. This is likely to be a direct response of GEC to complement attack and may represent a protective response of this cell.
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Affiliation(s)
- Guohui Ren
- Section of Nephrology, The University of Chicago, Chicago, Illinois, USA
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Yammani RR, Seetharam S, Dahms NM, Seetharam B. Transcobalamin II receptor interacts with megalin in the renal apical brush border membrane. J Membr Biol 2003; 193:57-66. [PMID: 12879166 DOI: 10.1007/s00232-002-2007-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2002] [Indexed: 10/26/2022]
Abstract
Purified human transcobalamin II receptor (TC II-R) binds to megalin, a 600 kDa endocytic receptor with an association constant, K(a), of 66 n M and bound(max) of 1.1 mole of TC II-R/mole of megalin both in the presence and absence of its ligand, transcobalamin II (TC II). Immunoprecipitation followed by immunoblotting of Triton X-100 extracts of the apical brush border membrane (BBM) from rabbit renal cortex revealed association of these two proteins. (35)[S]-TC II complexed with cobalamin (Cbl; Vitamin B(12)) bound to Sepharose-megalin affinity matrix and the binding was enhanced 5-fold when TC II-R was prebound to megalin. Megalin antiserum inhibited both the TC II-R-dependent and -independent binding of (35)[S]-TC II-Cbl to megalin, while TC II-R antiserum inhibited only the TC II-R-dependent binding. In rabbits with circulating antiserum to megalin, renal apical BBM megalin was present as an immune complex, but its levels were not altered. However, the protein levels of both TC II-R and the cation-independent mannose 6-phosphate receptor (CIMPR) were drastically reduced and the urinary excretion of TC II, albumin, and other low-molecular weight proteins was significantly increased. These results suggest that megalin contains a distinct single high-affinity binding site for TC II-R and their association in the native renal BBM is important for tubular reabsorption of many proteins, including TC II.
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Affiliation(s)
- R R Yammani
- Division of Gastroenterology and Hepatology, Department of Medicine, Zablocki Veteran's Administration Medical Center and Medical College of Wisconsin, 5000 West National Avenue, Milwaukee, Wisconsin, 53295, USA
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Abstract
Glomerular podocytes are highly specialized cells with a complex cytoarchitecture. Their most prominent features are interdigitated foot processes with filtration slits in between. These are bridged by the slit diaphragm, which plays a major role in establishing the selective permeability of the glomerular filtration barrier. Injury to podocytes leads to proteinuria, a hallmark of most glomerular diseases. New technical approaches have led to a considerable increase in our understanding of podocyte biology including protein inventory, composition and arrangement of the cytoskeleton, receptor equipment, and signaling pathways involved in the control of ultrafiltration. Moreover, disturbances of podocyte architecture resulting in the retraction of foot processes and proteinuria appear to be a common theme in the progression of acquired glomerular disease. In hereditary nephrotic syndromes identified over the last 2 years, all mutated gene products were localized in podocytes. This review integrates our recent physiological and molecular understanding of the role of podocytes during the maintenance and failure of the glomerular filtration barrier.
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Affiliation(s)
- Hermann Pavenstädt
- Division of Nephrology, Department of Medicine, University Hospital Freiburg, Freiburg, Germany.
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Ren G, Doshi M, Hack BK, Alexander JJ, Quigg RJ. Isolation and characterization of a novel rat factor H-related protein that is up-regulated in glomeruli under complement attack. J Biol Chem 2002; 277:48351-8. [PMID: 12374811 DOI: 10.1074/jbc.m205135200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The factor H family in humans is composed of seven distinct proteins, including factor H-related proteins (FHR) 1-5. All members contain tandemly arranged short consensus repeats (SCR) typical of the regulators of complement activation gene family. FHR-5 is unusual for this group of proteins, as it was initially identified as a component of immune deposits in glomerular diseases. During our cloning of the cDNA for rat factor H from glomerular epithelial cells (GEC), we identified an alternative 2729-bp cDNA transcript. The translated sequence encoded a protein containing 11 SCRs, most similar to SCRs 7-15 and 19-20 in native rat factor H, which is the same basic structure of human FHR-5. As such, this rat protein was termed FHR. Recombinant rat FHR produced in a eukaryotic expression system had a molecular mass of 78 kDa. In functional studies, recombinant FHR bound C3b and inhibited the complement alternative pathway in a dose-dependent fashion. Given the prominent expression of FHR-5 in human membranous nephropathy, a disease in which complement activation occurs in the vicinity of GEC, the expression of FHR in a rat model of this disease was evaluated. In both in vitro and in vivo models of complement activation on the GEC, FHR mRNA was up-regulated by a factor of 3-6-fold compared with controls in which complement could not be activated. Thus, we have identified a novel factor H family member in rats. This FHR protein is analogous to human FHR-5, both in structure and in potential involvement in glomerular immune complex diseases.
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Affiliation(s)
- Guohui Ren
- Section of Nephrology, Department of Medicine, the University of Chicago, Illinois 60637, USA
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Bao L, Spiller OB, St John PL, Haas M, Hack BK, Ren G, Cunningham PN, Doshi M, Abrahamson DR, Morgan BP, Quigg RJ. Decay-accelerating factor expression in the rat kidney is restricted to the apical surface of podocytes. Kidney Int 2002; 62:2010-21. [PMID: 12427125 DOI: 10.1046/j.1523-1755.2002.t01-1-00652.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Decay-accelerating factor (DAF) has inhibitory activity toward complement C3 and C5 convertases. DAF is present in human glomeruli and on cultured human glomerular visceral epithelial cells (GEC). We studied the distribution and function of rat DAF. METHODS Function-neutralizing antibodies (Abs) were raised against DAF. The distribution of DAF in vivo was determined by immunoelectron microscopy. Functional studies were performed in cultured GEC and following IV injection of anti-DAF Abs into rats. RESULTS DAF was present exclusively on the apical surfaces of GEC, and was not present on the basal surfaces of GEC, nor other glomerular or kidney cells. DAF was functionally active on cultured GEC, and served to limit complement activation in concert with CD59, an inhibitor of C5b-9 formation. Upon injection into normal rats, anti-DAF F(ab')2 Abs bound to GEC in vivo, yet there was no evidence for complement activation and animals did not develop abnormal albuminuria. Anti-megalin complement-activating IgG Abs were "planted" on GEC, which activated complement as evidenced by the presence of C3d on GEC. Attempts to inhibit DAF function with anti-DAF Abs did not affect the quantity of complement activation by these anti-megalin Abs, nor did it lead to development of abnormal albuminuria. In contrast, in the puromycin aminonucleoside model of GEC injury and proteinuria, anti-DAF Abs slowed the recovery from renal failure that occurs in this model. CONCLUSION In cultured rat GEC, DAF is an effective complement regulator. In vivo, DAF is present on GEC apical surfaces. Yet, it appears that DAF is not essential to prevent complement activation from occurring under normal circumstances and in those cases in which complement-activating Abs are present on the basal surfaces of GEC in vivo. However, in proteinuric conditions, DAF appears to be protective to GEC.
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Affiliation(s)
- Lihua Bao
- Section of Nephrology, The University of Chicago, Chicago, Illinois 60637, USA.
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