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Burke GW, Mitrofanova A, Fontanella AM, Vendrame F, Ciancio G, Vianna RM, Roth D, Ruiz P, Abitbol CL, Chandar J, Merscher S, Pugliese A, Fornoni A. Transplantation: platform to study recurrence of disease. Front Immunol 2024; 15:1354101. [PMID: 38495894 PMCID: PMC10940352 DOI: 10.3389/fimmu.2024.1354101] [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: 12/11/2023] [Accepted: 01/29/2024] [Indexed: 03/19/2024] Open
Abstract
Beyond the direct benefit that a transplanted organ provides to an individual recipient, the study of the transplant process has the potential to create a better understanding of the pathogenesis, etiology, progression and possible therapy for recurrence of disease after transplantation while at the same time providing insight into the original disease. Specific examples of this include: 1) recurrence of focal segmental glomerulosclerosis (FSGS) after kidney transplantation, 2) recurrent autoimmunity after pancreas transplantation, and 3) recurrence of disease after orthotopic liver transplantation (OLT) for cirrhosis related to progressive steatosis secondary to jejuno-ileal bypass (JIB) surgery. Our team has been studying these phenomena and their immunologic underpinnings, and we suggest that expanding the concept to other pathologic processes and/or transplanted organs that harbor the risk for recurrent disease may provide novel insight into the pathogenesis of a host of other disease processes that lead to organ failure.
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Affiliation(s)
- George William Burke
- Division of Kidney-Pancreas Transplantation, Department of Surgery, Miami Transplant Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Alla Mitrofanova
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
| | | | - Francesco Vendrame
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Gaetano Ciancio
- Division of Kidney-Pancreas Transplantation, Department of Surgery, Miami Transplant Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Rodrigo M. Vianna
- Department of Surgery, Miami Transplant Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - David Roth
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Phillip Ruiz
- Transplant Pathology, Immunology and Histocompatibility Laboratory University of Miami Department of Surgery, Miami Transplant Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Carolyn L. Abitbol
- Pediatric Nephrology & Hypertension, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Jayanthi Chandar
- Pediatric Kidney Transplant, Miami Transplant Institute, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Sandra Merscher
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
- Peggy and Harold Katz Family Drug Discovery Center, Department of Medicine, University of Miami - Miller School of Medicine, Miami, FL, United States
| | - Alberto Pugliese
- Department of Diabetes Immunology, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope, Duarte, CA, United States
| | - Alessia Fornoni
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
- Peggy and Harold Katz Family Drug Discovery Center, Department of Medicine, University of Miami - Miller School of Medicine, Miami, FL, United States
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Abstract
Idiopathic nephrotic syndrome often responds to immunosuppressive treatment. Nevertheless, this syndrome-and the drugs used to treat it-remain important causes of patient morbidity. Idiopathic nephrotic syndrome is usually caused by minimal change disease or FSGS, diseases that primarily affect the podocytes. In spite of decades of research, the underlying causes of both diseases remain incompletely understood. There is, however, a large body of observational and experimental data linking the immune system with both minimal change disease and FSGS, including associations with systemic infections and hematologic malignancies. Perhaps most compellingly, many different immunomodulatory drugs are effective for treating idiopathic nephrotic syndrome, including biologic agents that have well-defined immune targets. In fact, the unexpected efficacy of targeted therapeutic agents has provided important new insights into the pathogenesis of these diseases. Given the large number of drugs that are available to deplete or block specific cells and molecules within the immune system, a better understanding of the immunologic causes of idiopathic nephrotic syndrome may lead to better diagnostic and therapeutic approaches.
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Affiliation(s)
- Ruth E. Campbell
- Division of Renal Diseases and Hypertension, University of Colorado School of Medicine, Aurora, Colorado
| | - Joshua M. Thurman
- Division of Renal Diseases and Hypertension, University of Colorado School of Medicine, Aurora, Colorado
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Mitrofanova A, Fontanella A, Tolerico M, Mallela S, Molina David J, Zuo Y, Boulina M, Kim JJ, Santos J, Ge M, Sloan A, Issa W, Gurumani M, Pressly J, Ito M, Kretzler M, Eddy S, Nelson R, Merscher S, Burke G, Fornoni A. Activation of Stimulator of IFN Genes (STING) Causes Proteinuria and Contributes to Glomerular Diseases. J Am Soc Nephrol 2022; 33:2153-2173. [PMID: 36198430 PMCID: PMC9731637 DOI: 10.1681/asn.2021101286] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 09/06/2022] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND The signaling molecule stimulator of IFN genes (STING) was identified as a crucial regulator of the DNA-sensing cyclic GMP-AMP synthase (cGAS)-STING pathway, and this signaling pathway regulates inflammation and energy homeostasis under conditions of obesity, kidney fibrosis, and AKI. However, the role of STING in causing CKD, including diabetic kidney disease (DKD) and Alport syndrome, is unknown. METHODS To investigate whether STING activation contributes to the development and progression of glomerular diseases such as DKD and Alport syndrome, immortalized human and murine podocytes were differentiated for 14 days and treated with a STING-specific agonist. We used diabetic db/db mice, mice with experimental Alport syndrome, C57BL/6 mice, and STING knockout mice to assess the role of the STING signaling pathway in kidney failure. RESULTS In vitro, murine and human podocytes express all of the components of the cGAS-STING pathway. In vivo, activation of STING renders C57BL/6 mice susceptible to albuminuria and podocyte loss. STING is activated at baseline in mice with experimental DKD and Alport syndrome. STING activation occurs in the glomerular but not the tubulointerstitial compartment in association with autophagic podocyte death in Alport syndrome mice and with apoptotic podocyte death in DKD mouse models. Genetic or pharmacologic inhibition of STING protects from progression of kidney disease in mice with DKD and Alport syndrome and increases lifespan in Alport syndrome mice. CONCLUSION The activation of the STING pathway acts as a mediator of disease progression in DKD and Alport syndrome. Targeting STING may offer a therapeutic option to treat glomerular diseases of metabolic and nonmetabolic origin or prevent their development, progression, or both.
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Affiliation(s)
- Alla Mitrofanova
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida
- Department of Surgery, University of Miami, Miller School of Medicine, Miami, Florida
| | - Antonio Fontanella
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida
| | - Matthew Tolerico
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida
| | - Shamroop Mallela
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida
| | - Judith Molina David
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida
| | - Yiqin Zuo
- Department of Pathology, University of Miami Medical Group, Miller School of Medicine, Miami, Florida
| | - Marcia Boulina
- Diabetes Research Institute, University of Miami, Miller School of Medicine, Miami, Florida
| | - Jin-Ju Kim
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida
| | - Javier Santos
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida
| | - Mengyuan Ge
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida
| | - Alexis Sloan
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida
| | - Wadih Issa
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida
| | - Margaret Gurumani
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida
| | - Jeffrey Pressly
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida
| | - Marie Ito
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida
| | - Matthias Kretzler
- Division of Nephrology, Departments of Internal Medicine and Computational Medicine and Bioinformatics, University of Michigan School of Medicine, Ann Arbor, Michigan
| | - Sean Eddy
- Division of Nephrology, Departments of Internal Medicine and Computational Medicine and Bioinformatics, University of Michigan School of Medicine, Ann Arbor, Michigan
| | - Robert Nelson
- Chronic Kidney Disease Section, National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, Arizona
| | - Sandra Merscher
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida
| | - George Burke
- Department of Surgery, University of Miami, Miller School of Medicine, Miami, Florida
- Diabetes Research Institute, University of Miami, Miller School of Medicine, Miami, Florida
| | - Alessia Fornoni
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida
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Datta S, Kataria R, Zhang JY, Moore S, Petitpas K, Mohamed A, Zahler N, Pollak MR, Olabisi OA. Kidney Disease-Associated APOL1 Variants Have Dose-Dependent, Dominant Toxic Gain-of-Function. J Am Soc Nephrol 2020; 31:2083-2096. [PMID: 32675303 PMCID: PMC7461666 DOI: 10.1681/asn.2020010079] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 05/12/2020] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Two coding renal risk variants (RRVs) of the APOL1 gene (G1 and G2) are associated with large increases in CKD rates among populations of recent African descent, but the underlying molecular mechanisms are unknown. Mammalian cell culture models are widely used to study cytotoxicity of RRVs, but results have been contradictory. It remains unclear whether cytotoxicity is RRV-dependent or driven solely by variant-independent overexpression. It is also unknown whether expression of the reference APOL1 allele, the wild-type G0, could prevent cytotoxicity of RRVs. METHODS We generated tetracycline-inducible APOL1 expression in human embryonic kidney HEK293 cells and examined the effects of increased expression of APOL1 (G0, G1, G2, G0G0, G0G1, or G0G2) on known cytotoxicity phenotypes, including reduced viability, increased swelling, potassium loss, aberrant protein phosphorylation, and dysregulated energy metabolism. Furthermore, whole-genome transcriptome analysis examined deregulated canonical pathways. RESULTS At moderate expression, RRVs but not G0 caused cytotoxicity in a dose-dependent manner that coexpression of G0 did not reduce. RRVs also have dominant effects on canonical pathways relevant for the cellular stress response. CONCLUSIONS In HEK293 cells, RRVs exhibit a dominant toxic gain-of-function phenotype that worsens with increasing expression. These observations suggest that high steady-state levels of RRVs may underlie cellular injury in APOL1 nephropathy, and that interventions that reduce RRV expression in kidney compartments may mitigate APOL1 nephropathy.
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Affiliation(s)
- Somenath Datta
- Division of Nephrology and Duke Molecular Physiology Institute, Duke University, Durham, North Carolina
- Division of Nephrology, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Rama Kataria
- Division of Nephrology, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Jia-Yue Zhang
- Harvard Medical School, Boston, Massachusetts
- Division of Nephrology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Savannah Moore
- Division of Nephrology, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Kaitlyn Petitpas
- Division of Nephrology, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Adam Mohamed
- Division of Nephrology, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | | | - Martin R Pollak
- Harvard Medical School, Boston, Massachusetts
- Division of Nephrology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Opeyemi A Olabisi
- Division of Nephrology and Duke Molecular Physiology Institute, Duke University, Durham, North Carolina
- Division of Nephrology, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
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Tian M, Carroll LS, Tang L, Uehara H, Westenfelder C, Ambati BK, Huang Y. Systemic AAV10.COMP-Ang1 rescues renal glomeruli and pancreatic islets in type 2 diabetic mice. BMJ Open Diabetes Res Care 2020; 8:8/1/e000882. [PMID: 32792355 PMCID: PMC7430492 DOI: 10.1136/bmjdrc-2019-000882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 02/05/2020] [Accepted: 06/14/2020] [Indexed: 12/22/2022] Open
Abstract
INTRODUCTION Diabetic hyperglycemia causes progressive and generalized damage to the microvasculature. In renal glomeruli, this results in the loss of podocytes with consequent loss of constitutive angiopoietin-1 (Ang1) signaling, which is required for stability of the glomerular endothelium. Repeated tail vein injection of adenovirus expressing COMP-Ang1 (a stable bioengineered form of Ang1) was previously reported to improve diabetic glomerular damage despite the liver and lungs being primary targets of adenoviral infection. We thus hypothesized that localizing delivery of sustained COMP-Ang1 to the kidney could increase its therapeutic efficacy and safety for the treatment of diabetes. RESEARCH DESIGN AND METHODS Using AAVrh10 adeno-associated viral capsid with enhanced kidney tropism, we treated 10-week-old uninephrectomized db/db mice (a model of type 2 diabetes) with a single dose of AAVrh10.COMP-Ang1 delivered via the intracarotid artery, compared with untreated diabetic db/db control and non-diabetic db/m mice. RESULTS Surprisingly, both glomerular and pancreatic capillaries expressed COMP-Ang1, compensating for diabetes-induced loss of tissue Ang1. Importantly, treatment with AAVrh10.COMP-Ang1 yielded a significant reduction of glycemia (blood glucose, 241±193 mg/dL vs 576±31 mg/dL; glycosylated hemoglobin, 7.2±1.5% vs 11.3±1.3%) and slowed the progression of albuminuria and glomerulosclerosis in db/db mice by 70% and 61%, respectively, compared with untreated diabetic db/db mice. Furthermore, COMP-Ang1 ameliorated diabetes-induced increases of NF-kBp65, nicotinamide adenine dinucleotide phosphate (NAPDH) oxidase-2 (Nox2), p47phox and productions of myeloperoxidase, the inflammatory markers in both renal and pancreatic tissues, and improved beta-cell density in pancreatic islets. CONCLUSIONS These results highlight the potential of localized Ang1 therapy for treatment of diabetic visceropathies and provide a mechanistic explanation for reported improvements in glucose control via Ang1/Tie2 signaling in the pancreas.
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Affiliation(s)
- Mi Tian
- Internal Medicine/Nephrology, University of Utah, Salt Lake City, Utah, USA
- Internal Medicine/Nephrology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Lara S Carroll
- Ophthalmology and Visual Science, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA
| | - Li Tang
- Internal Medicine/Nephrology, University of Utah, Salt Lake City, Utah, USA
| | - Hironori Uehara
- Ophthalmology and Visual Science, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA
| | | | - Balamurali K Ambati
- Ophthalmology and Visual Science, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA
| | - Yufeng Huang
- Internal Medicine/Nephrology, University of Utah, Salt Lake City, Utah, USA
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γδT Cells Exacerbate Podocyte Injury via the CD28/B7-1-Phosphor-SRC Kinase Pathway. BIOMED RESEARCH INTERNATIONAL 2018; 2018:5647120. [PMID: 29862277 PMCID: PMC5976931 DOI: 10.1155/2018/5647120] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 03/08/2018] [Accepted: 04/08/2018] [Indexed: 01/25/2023]
Abstract
Primary nephrotic syndrome (PNS) is a devastating pediatric disorder. However, its mechanism remains unclear. Previous studies detected B7-1 in podocytes; meanwhile, γδT cells play pivotal roles in immune diseases. Therefore, this study aimed to assess whether and how γδT cells impact podocytes via the CD28/B7-1 pathway. WT and TCRδ−/− mice were assessed. LPS was used to induce nephropathy. Total γδT and CD28+γδT cells were quantitated in mouse spleen and kidney samples. B7-1 and phosphor-SRC levels in the kidney were detected as well. In vitro, γδT cells from the mouse spleen were cocultured with mouse podocytes, and apoptosis rate and phosphor-SRC expression in podocytes were assessed. Compared with control mice, WT mice with LPS nephropathy showed increased amounts of γδT cells in the kidney. Kidney injury was alleviated in TCRδ−/− mice. Meanwhile, B7-1 and phosphor-SRC levels were increased in the kidney from WT mice with LPS nephropathy. CD28+γδT cells were decreased, indicating CD28 may play a role in LPS nephropathy. Immunofluorescence colocalization analysis revealed a tight association of γδT cells with B7-1 in the kidney. High B7-1 expression was detected in podocytes treated with LPS. Podocytes cocultured with γδT cells showed higher phosphor-SRC and apoptosis rate than other cell groups. Furthermore, CD28/B7-1 blockage with CTLA4-Ig in vitro relieved podocyte injury. γδT cells exacerbate podocyte injury via CD28/B7-1 signaling, with downstream involvement of phosphor-SRC. The CD28/B7-1 blocker CTLA4-Ig prevented progressive podocyte injury, providing a potential therapeutic tool for PNS.
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Lv LL, Feng Y, Wen Y, Wu WJ, Ni HF, Li ZL, Zhou LT, Wang B, Zhang JD, Crowley SD, Liu BC. Exosomal CCL2 from Tubular Epithelial Cells Is Critical for Albumin-Induced Tubulointerstitial Inflammation. J Am Soc Nephrol 2018; 29:919-935. [PMID: 29295871 DOI: 10.1681/asn.2017050523] [Citation(s) in RCA: 143] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 11/14/2017] [Indexed: 11/03/2022] Open
Abstract
Albuminuria is a key instigator of tubulointerstitial inflammation associated with CKD, but the mechanism through which filtered albumin propagates renal injury remains unclear. In this study, we explored the role in this process of exosome mRNA released from tubular epithelial cells (TECs). Compared with control mice, acute and chronic kidney injury models had more exosomes containing inflammatory cytokine mRNA, particularly the chemokine CCL2, in kidneys and urine. In vitro stimulation of TECs with BSA recapitulated this finding. Notably, the internalization of purified TEC exosomes by cultured macrophages increased if TECs were exposed to BSA. Macrophage internalization of exosomes from BSA-treated TECs led to an enhanced inflammatory response and macrophage migration, but CCL2 silencing in TECs prevented these effects. Using a GFP-CCL2 fusion mRNA construct, we observed direct transfer of CCL2 mRNA from TEC exosomes to macrophages. Mice subjected to tail vein injection of purified BSA-treated TEC exosomes developed tubular injury with renal inflammatory cell infiltration. However, injection of exosomes from BSA-treated CCL2-deficient TECs induced less severe kidney inflammation. Finally, in patients with IgA nephropathy, the increase of proteinuria correlated with augmented urinary excretion of exosomes with exaggerated expression of CCL2 mRNA. Moreover, the level of CCL2 mRNA in urinary exosomes correlated closely with levels of renal interstitial macrophage infiltration in these patients. Our studies demonstrate that the increasing release of exosomes that transfer CCL2 mRNA from TECs to macrophages constitutes a critical mechanism of albumin-induced tubulointerstitial inflammation.
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Affiliation(s)
- Lin-Li Lv
- Institute of Nephrology, Zhongda Hospitial, Southeast University School of Medicine, Nanjing, China; and
| | - Ye Feng
- Institute of Nephrology, Zhongda Hospitial, Southeast University School of Medicine, Nanjing, China; and
| | - Yi Wen
- Institute of Nephrology, Zhongda Hospitial, Southeast University School of Medicine, Nanjing, China; and
| | - Wei-Jun Wu
- Institute of Nephrology, Zhongda Hospitial, Southeast University School of Medicine, Nanjing, China; and
| | - Hai-Feng Ni
- Institute of Nephrology, Zhongda Hospitial, Southeast University School of Medicine, Nanjing, China; and
| | - Zuo-Lin Li
- Institute of Nephrology, Zhongda Hospitial, Southeast University School of Medicine, Nanjing, China; and
| | - Le-Ting Zhou
- Institute of Nephrology, Zhongda Hospitial, Southeast University School of Medicine, Nanjing, China; and
| | - Bin Wang
- Institute of Nephrology, Zhongda Hospitial, Southeast University School of Medicine, Nanjing, China; and
| | - Jian-Dong Zhang
- Institute of Nephrology, Zhongda Hospitial, Southeast University School of Medicine, Nanjing, China; and
| | - Steven D Crowley
- Division of Nephrology, Department of Medicine, Duke University and Durham Veterans Affairs Medical Centers, Durham, North Carolina
| | - Bi-Cheng Liu
- Institute of Nephrology, Zhongda Hospitial, Southeast University School of Medicine, Nanjing, China; and
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Wang X, Dande RR, Yu H, Samelko B, Miller RE, Altintas MM, Reiser J. TRPC5 Does Not Cause or Aggravate Glomerular Disease. J Am Soc Nephrol 2017; 29:409-415. [PMID: 29061651 DOI: 10.1681/asn.2017060682] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 09/26/2017] [Indexed: 12/13/2022] Open
Abstract
Transient receptor potential channel 5 (TRPC5) is highly expressed in brain and kidney and mediates calcium influx and promotes cell migration. In the kidney, loss of TRPC5 function has been reported to benefit kidney filter dynamics by balancing podocyte cytoskeletal remodeling. However, in vivo gain-in-function studies of TRPC5 with respect to kidney function have not been reported. To address this gap, we developed two transgenic mouse models on the C57BL/6 background by overexpressing either wild-type TRPC5 or a TRPC5 ion-pore mutant. Compared with nontransgenic controls, neither transgenic model exhibited an increase in proteinuria at 8 months of age or a difference in LPS-induced albuminuria. Moreover, activation of TRPC5 by Englerin A did not stimulate proteinuria, and inhibition of TRPC5 by ML204 did not significantly lower the level of LPS-induced proteinuria in any group. Collectively, these data suggest that the overexpression or activation of the TRPC5 ion channel does not cause kidney barrier injury or aggravate such injury under pathologic conditions.
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Affiliation(s)
- Xuexiang Wang
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
| | - Ranadheer R Dande
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
| | - Hao Yu
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
| | - Beata Samelko
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
| | - Rachel E Miller
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
| | - Mehmet M Altintas
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
| | - Jochen Reiser
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
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Khan S, Cabral PD, Schilling WP, Schmidt ZW, Uddin AN, Gingras A, Madhavan SM, Garvin JL, Schelling JR. Kidney Proximal Tubule Lipoapoptosis Is Regulated by Fatty Acid Transporter-2 (FATP2). J Am Soc Nephrol 2017; 29:81-91. [PMID: 28993506 DOI: 10.1681/asn.2017030314] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 08/08/2017] [Indexed: 11/03/2022] Open
Abstract
Albuminuria and tubular atrophy are among the highest risks for CKD progression to ESRD. A parsimonious mechanism involves leakage of albumin-bound nonesterified fatty acids (NEFAs) across the damaged glomerular filtration barrier and subsequent reabsorption by the downstream proximal tubule, causing lipoapoptosis. We sought to identify the apical proximal tubule transporter that mediates NEFA uptake and cytotoxicity. We observed transporter-mediated uptake of fluorescently labeled NEFA in cultured proximal tubule cells and microperfused rat proximal tubules, with greater uptake from the apical surface than from the basolateral surface. Protein and mRNA expression analyses revealed that kidney proximal tubules express transmembrane fatty acid transporter-2 (FATP2), encoded by Slc27a2, but not the other candidate transporters CD36 and free fatty acid receptor 1. Kidney FATP2 localized exclusively to proximal tubule epithelial cells along the apical but not the basolateral membrane. Treatment of mice with lipidated albumin to induce proteinuria caused a decrease in the proportion of tubular epithelial cells and an increase in the proportion of interstitial space in kidneys from wild-type but not Slc27a2-/- mice. Ex vivo microperfusion and in vitro experiments with NEFA-bound albumin at concentrations that mimic apical proximal tubule exposure during glomerular injury revealed significantly reduced NEFA uptake and palmitate-induced apoptosis in microperfused Slc27a2-/- proximal tubules and Slc27a2-/- or FATP2 shRNA-treated proximal tubule cell lines compared with wild-type or scrambled oligonucleotide-treated cells, respectively. We conclude that FATP2 is a major apical proximal tubule NEFA transporter that regulates lipoapoptosis and may be an amenable target for the prevention of CKD progression.
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Affiliation(s)
- Shenaz Khan
- Department of Medicine, The MetroHealth System and
| | - Pablo D Cabral
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
| | - William P Schilling
- Department of Medicine, The MetroHealth System and.,Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
| | | | - Asif N Uddin
- Department of Medicine, The MetroHealth System and
| | | | | | - Jeffrey L Garvin
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
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Predictability of Urinary CD80 in the Relapse of Primary Nephrotic Syndrome. BIOMED RESEARCH INTERNATIONAL 2017; 2017:9429314. [PMID: 28951877 PMCID: PMC5603140 DOI: 10.1155/2017/9429314] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 07/27/2017] [Indexed: 02/02/2023]
Abstract
Purpose The current study is aimed at investigating whether urinary CD80 is reliable to predict the recurrence of pediatric PNS. Materials and Methods A total of 128 children, 105 males and 23 females, were enrolled in this study. Urinary samples were collected from SSNS and SRNS patients and 25 healthy children as controls. Urinary CD80 was measured by ELISA and adjusted for urinary creatinine excretion. Results Urinary CD80 in relapse stage of SSNS was significantly higher, and the urinary CD80 of paired relapse and remission stages of each SSNS patient were also significantly different. No significant difference was found between the urinary CD80 in SRNS relapse group, SRNS remission group, and the control group. Similarly, there was no significant difference between frequent SSNS and not frequent SSNS in remission group, as well as the relapse group. There is no correlation between urinary CD80 and 24-hour urinary protein. Conclusion The increase of urinary CD80 was closely associated with the relapse of SSNS but was not related to the frequency of relapse. The urinary CD80 changes of concentration were reliable to predict the recurrence of SSNS. However, it cannot be used to predicate the frequent recurrence of PNS.
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11
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Sung SSJ, Ge Y, Dai C, Wang H, Fu SM, Sharma R, Hahn YS, Yu J, Le TH, Okusa MD, Bolton WK, Lawler JR. Dependence of Glomerulonephritis Induction on Novel Intraglomerular Alternatively Activated Bone Marrow-Derived Macrophages and Mac-1 and PD-L1 in Lupus-Prone NZM2328 Mice. THE JOURNAL OF IMMUNOLOGY 2017; 198:2589-2601. [PMID: 28219886 DOI: 10.4049/jimmunol.1601565] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 01/26/2017] [Indexed: 01/01/2023]
Abstract
Glomerular damage mediated by glomerulus-infiltrating myeloid-derived cells is a key pathogenic event in lupus nephritis (LN), but the process is poorly understood. Confocal microscopy of kidney sections and flow cytometry analysis of glomerular cells from magnetic bead-purified glomeruli have identified glomerulus-infiltrating leukocyte populations in NZM2328 (NZM) lupus-prone mice with spontaneous chronic glomerulonephritis (GN) and anti-glomerular basement membrane-induced nephritis. The occurrence of a major glomerulus-infiltrating CD11b+F4/80-I-A- macrophage population exhibiting the markers programmed death ligand-1 (PD-L1), Mac-2, and macrophage mannose receptor (CD206) and producing Klf4, Il10, Retnla, Tnf, and Il6 mRNA, which are known to be expressed by alternatively activated (M2b) macrophages, correlated with proteinuria status. In NZM mice with spontaneous LN, glomerular macrophage infiltration is predominant. CD11b+F4/80-I-A- intraglomerular macrophages and polymorphonuclear neutrophils (PMN) are important in inducing GN, as anti-CD11b and -ICAM-1 mAb inhibited both proteinuria and macrophage and PMN infiltration. The predominant and high expression of PD-L1 by CD11b+F4/80-I-A- glomerular macrophages in kidneys of mice with GN and the inhibition of proteinuria by anti-PD-L1 mAb supported the pathogenic role of these macrophages but not the PD-L1- PMN in GN development and in inducing podocyte damage. In NZM mice with spontaneous chronic GN and severe proteinuria, few glomerulus-infiltrating PMN were found, leaving macrophages and, to a less extent, dendritic cells as the major infiltrating leukocytes. Taken together, these data support the important pathogenic effect of CD11b+F4/80-I-A- M2b-like glomerulus-infiltrating macrophages in LN and reinforce macrophages as a promising target for GN treatment.
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Affiliation(s)
- Sun-Sang J Sung
- Department of Medicine, University of Virginia Health Sciences Center, Charlottesville, VA 22908; .,Center for Immunity, Inflammation, and Regenerative Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - Yan Ge
- Department of Medicine, University of Virginia Health Sciences Center, Charlottesville, VA 22908.,Center for Immunity, Inflammation, and Regenerative Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908; and
| | - Chao Dai
- Department of Medicine, University of Virginia Health Sciences Center, Charlottesville, VA 22908.,Center for Immunity, Inflammation, and Regenerative Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - Hongyang Wang
- Department of Medicine, University of Virginia Health Sciences Center, Charlottesville, VA 22908.,Center for Immunity, Inflammation, and Regenerative Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - Shu Man Fu
- Department of Medicine, University of Virginia Health Sciences Center, Charlottesville, VA 22908.,Center for Immunity, Inflammation, and Regenerative Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908; and
| | - Rahul Sharma
- Department of Medicine, University of Virginia Health Sciences Center, Charlottesville, VA 22908.,Center for Immunity, Inflammation, and Regenerative Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - Young S Hahn
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908; and
| | - Jing Yu
- Department of Cell Biology, University of Virginia Health Sciences Center, Charlottesville, VA 22908
| | - Thu H Le
- Department of Medicine, University of Virginia Health Sciences Center, Charlottesville, VA 22908.,Center for Immunity, Inflammation, and Regenerative Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - Mark D Okusa
- Department of Medicine, University of Virginia Health Sciences Center, Charlottesville, VA 22908.,Center for Immunity, Inflammation, and Regenerative Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - Warren K Bolton
- Department of Medicine, University of Virginia Health Sciences Center, Charlottesville, VA 22908.,Center for Immunity, Inflammation, and Regenerative Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - Jessica R Lawler
- Department of Medicine, University of Virginia Health Sciences Center, Charlottesville, VA 22908.,Center for Immunity, Inflammation, and Regenerative Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908
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12
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Abstract
Glomerular diseases are common and important. They can arise from systemic inflammatory or metabolic diseases that affect the kidney. Alternately, they are caused primarily by local glomerular abnormalities, including genetic diseases. Both intrinsic glomerular cells and leukocytes are critical to the healthy glomerulus and to glomerular dysregulation in disease. Mesangial cells, endothelial cells, podocytes, and parietal epithelial cells within the glomerulus all play unique and specialized roles. Although a specific disease often primarily affects a particular cell type, the close proximity, and interdependent functions and interactions between cells mean that even diseases affecting one cell type usually indirectly influence others. In addition to those cells intrinsic to the glomerulus, leukocytes patrol the glomerulus in health and mediate injury in disease. Distinct leukocyte types and subsets are present, with some being involved in different ways in an individual glomerular disease. Cells of the innate and adaptive immune systems are important, directing systemic immune and inflammatory responses, locally mediating injury, and potentially dampening inflammation and facilitating repair. The advent of new genetic and molecular techniques, and new disease models means that we better understand both the basic biology of the glomerulus and the pathogenesis of glomerular disease. This understanding should lead to better diagnostic techniques, biomarkers, and predictors of prognosis, disease severity, and relapse. With this knowledge comes the promise of better therapies in the future, directed toward halting pathways of injury and fibrosis, or interrupting the underlying pathophysiology of the individual diseases that lead to significant and progressive glomerular disease.
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Affiliation(s)
- A. Richard Kitching
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Victoria, Australia
- Department of Nephrology, and
- Department of Pediatric Nephrology, Monash Medical Centre, Clayton, Victoria, Australia
| | - Holly L. Hutton
- Centre for Inflammatory Diseases, Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Victoria, Australia
- Department of Nephrology, and
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13
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Mallipattu SK, Guo Y, Revelo MP, Roa-Peña L, Miller T, Ling J, Shankland SJ, Bialkowska AB, Ly V, Estrada C, Jain MK, Lu Y, Ma'ayan A, Mehrotra A, Yacoub R, Nord EP, Woroniecki RP, Yang VW, He JC. Krüppel-Like Factor 15 Mediates Glucocorticoid-Induced Restoration of Podocyte Differentiation Markers. J Am Soc Nephrol 2016; 28:166-184. [PMID: 27288011 DOI: 10.1681/asn.2015060672] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 04/05/2016] [Indexed: 12/18/2022] Open
Abstract
Podocyte injury is the inciting event in primary glomerulopathies, such as minimal change disease and primary FSGS, and glucocorticoids remain the initial and often, the primary treatment of choice for these glomerulopathies. Because inflammation is not readily apparent in these diseases, understanding the direct effects of glucocorticoids on the podocyte, independent of the immunomodulatory effects, may lead to the identification of targets downstream of glucocorticoids that minimize toxicity without compromising efficacy. Several studies showed that treatment with glucocorticoids restores podocyte differentiation markers and normal ultrastructure and improves cell survival in murine podocytes. We previously determined that Krüppel-like factor 15 (KLF15), a kidney-enriched zinc finger transcription factor, is required for restoring podocyte differentiation markers in mice and human podocytes under cell stress. Here, we show that in vitro treatment with dexamethasone induced a rapid increase of KLF15 expression in human and murine podocytes and enhanced the affinity of glucocorticoid receptor binding to the promoter region of KLF15 In three independent proteinuric murine models, podocyte-specific loss of Klf15 abrogated dexamethasone-induced podocyte recovery. Furthermore, knockdown of KLF15 reduced cell survival and destabilized the actin cytoskeleton in differentiated human podocytes. Conversely, overexpression of KLF15 stabilized the actin cytoskeleton under cell stress in human podocytes. Finally, the level of KLF15 expression in the podocytes and glomeruli from human biopsy specimens correlated with glucocorticoid responsiveness in 35 patients with minimal change disease or primary FSGS. Thus, these studies identify the critical role of KLF15 in mediating the salutary effects of glucocorticoids in the podocyte.
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Affiliation(s)
| | - Yiqing Guo
- Division of Nephrology, Departments of Medicine and
| | - Monica P Revelo
- Department of Pathology, University of Utah, Salt Lake City, Utah
| | | | | | - Jason Ling
- Division of Nephrology, Departments of Medicine and
| | - Stuart J Shankland
- Division of Nephrology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington
| | - Agnieszka B Bialkowska
- Division of Gastroenterology, Department of Medicine, Stony Brook University, Stony Brook, New York
| | - Victoria Ly
- Division of Nephrology, Departments of Medicine and
| | | | - Mukesh K Jain
- Case Cardiovascular Institute Research Institute, Department of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Yuan Lu
- Case Cardiovascular Institute Research Institute, Department of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Avi Ma'ayan
- Department of Pharmacology and Systems Therapeutics and
| | - Anita Mehrotra
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York; and
| | - Rabi Yacoub
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York; and
| | | | | | - Vincent W Yang
- Division of Gastroenterology, Department of Medicine, Stony Brook University, Stony Brook, New York
| | - John C He
- Department of Pharmacology and Systems Therapeutics and.,Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York; and.,Renal Section, James J. Peters Veterans Affairs Medical Center, New York, New York
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14
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FSGS: Diagnosis and Diagnostic Work-Up. BIOMED RESEARCH INTERNATIONAL 2016; 2016:4632768. [PMID: 27314022 PMCID: PMC4894996 DOI: 10.1155/2016/4632768] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 05/03/2016] [Indexed: 01/13/2023]
Abstract
Focal segmental glomerulosclerosis is a histologic lesion, rather than a clinical disease. FSGS is common cause of nephrotic syndrome in both adults and children worldwide. In the United States it is the most common primary glomerular disease resulting in end-stage renal disease and recent reports have suggested that its incidence might be on the rise. Currently the incidence is estimated to be 7 per million. The podocyte is the cellular target cell in FSGS and in recent years substantial insight in the pathogenesis and genetics of FSGS have accumulated. Furthermore the discovery of potential novel biomarkers to diagnose FSGS and monitor disease activity has renewed interest in this disease. In this review article we will focus on the clinical presentation and diagnosis of FSGS.
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15
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Successful Treatment of Focal Segmental Glomerulosclerosis after Kidney Transplantation with Plasma Exchange and Abatacept in a Patient with Juvenile Rheumatoid Arthritis. Case Rep Transplant 2016; 2016:7137584. [PMID: 27088031 PMCID: PMC4818792 DOI: 10.1155/2016/7137584] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 03/01/2016] [Accepted: 03/03/2016] [Indexed: 11/18/2022] Open
Abstract
Recurrent focal segmental glomerulosclerosis (FSGS) after renal transplantation is difficult to treat. Recently a series of four patients unresponsive to plasma exchange (PE) and rituximab, who were successfully treated with abatacept, has been reported. We present a 26-year-old Caucasian patient who suffered from juvenile rheumatoid arthritis and developed severe proteinuria eleven days after transplantation. An allograft biopsy was suggestive of recurrent focal segmental glomerulosclerosis. He did not respond to PE therapy. A first dose of abatacept produced partial remission. Four weeks later proteinuria again increased and a second biopsy showed progression of disease. After another ineffective course of PE he was given a second dose of abatacept, which was followed by rapid, complete, and sustained resolution of proteinuria. This treatment caused a significant increase in BK and JC viremia. Whether abatacept ameliorated proteinuria via an effect on podocytes or on the patient's primary disease remains speculative.
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16
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Tian X, Ishibe S. Targeting the podocyte cytoskeleton: from pathogenesis to therapy in proteinuric kidney disease. Nephrol Dial Transplant 2016; 31:1577-83. [PMID: 26968197 DOI: 10.1093/ndt/gfw021] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 01/24/2016] [Indexed: 01/11/2023] Open
Abstract
Glomerular injury often incites a progression to chronic kidney disease, which affects millions of patients worldwide. Despite our current understanding of this disease's pathogenesis, there is still a lack of therapy available to curtail its progression. However, exciting new data strongly suggest the podocyte-an actin-rich, terminally differentiated epithelial cell that lines the outside of the glomerular filtration barrier-as a therapeutic target. The importance of podocytes in the pathogenesis of human nephrotic syndrome is best characterized by identification of genetic mutations, many of which regulate the actin cytoskeleton. The intricate regulation of the podocyte actin cytoskeleton is fundamental in preserving an intact glomerular filtration barrier, and this knowledge has inspired new research targeting actin-regulating proteins in these cells. This review will shed light on recent findings, which have furthered our understanding of the molecular mechanisms regulating podocyte actin dynamics, as well as discoveries that have therapeutic implications in the treatment of proteinuric kidney disease.
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Affiliation(s)
- Xuefei Tian
- Section of Nephrology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Shuta Ishibe
- Section of Nephrology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
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17
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Focal segmental glomerular sclerosis: do not overlook the role of immune response. J Nephrol 2016; 29:525-34. [DOI: 10.1007/s40620-016-0272-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 01/28/2016] [Indexed: 10/22/2022]
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18
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Immunologic Changes Implicated in the Pathogenesis of Focal Segmental Glomerulosclerosis. BIOMED RESEARCH INTERNATIONAL 2016; 2016:2150451. [PMID: 26989679 PMCID: PMC4773535 DOI: 10.1155/2016/2150451] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 01/27/2016] [Indexed: 01/09/2023]
Abstract
Focal segmental glomerulosclerosis is a histological pattern on renal biopsy caused by diverse mechanisms. In its primary form, a circulatory factor is implicated in disease onset and recurrence. The natural history of primary FSGS is unpredictable, since some patients are unresponsive towards immunosuppressive measures. Immunologic changes, leading to a proinflammatory or profibrotic milieu, have been implicated in disease progression, namely, glomerular scarring, eventually leading to end-stage renal disease. Among these, interleukin-1ß, tumor-necrosis factor-α (TNF-α), and transforming growth factor-ß1 (TGF-ß1) have emerged as important factors. Translating these findings into clinical practice dampened the enthusiasm, since both TNF-α and TGF-ß1 blockade failed to achieve significant control of the disease. More recently, a role of the complement system has been demonstrated which in fact may be another attractive target in clinical practice. Rituximab, blocking CD20-bearing cells, demonstrated conflicting data regarding efficacy in FSGS. Finally, the T-cell costimulating molecule B7-1 (CD80) is implicated in development of proteinuria in general. Blockade of this target demonstrated significant benefits in a small cohort of resistant patients. Taken together, this review focuses on immunology of FSGS, attributable to either the disease or progression, and discusses novel therapeutic approaches aiming at targeting immunologic factors.
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19
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Abstract
Podocytes are highly specialized cells of the kidney glomerulus that wrap around capillaries and that neighbor cells of the Bowman’s capsule. When it comes to glomerular filtration, podocytes play an active role in preventing plasma proteins from entering the urinary ultrafiltrate by providing a barrier comprising filtration slits between foot processes, which in aggregate represent a dynamic network of cellular extensions. Foot processes interdigitate with foot processes from adjacent podocytes and form a network of narrow and rather uniform gaps. The fenestrated endothelial cells retain blood cells but permit passage of small solutes and an overlying basement membrane less permeable to macromolecules, in particular to albumin. The cytoskeletal dynamics and structural plasticity of podocytes as well as the signaling between each of these distinct layers are essential for an efficient glomerular filtration and thus for proper renal function. The genetic or acquired impairment of podocytes may lead to foot process effacement (podocyte fusion or retraction), a morphological hallmark of proteinuric renal diseases. Here, we briefly discuss aspects of a contemporary view of podocytes in glomerular filtration, the patterns of structural changes in podocytes associated with common glomerular diseases, and the current state of basic and clinical research.
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Affiliation(s)
- Jochen Reiser
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Mehmet M Altintas
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA
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20
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Delville M, Baye E, Durrbach A, Audard V, Kofman T, Braun L, Olagne J, Nguyen C, Deschênes G, Moulin B, Delahousse M, Kesler-Roussey G, Beaudreuil S, Martinez F, Rabant M, Grimbert P, Gallazzini M, Terzi F, Legendre C, Canaud G. B7-1 Blockade Does Not Improve Post-Transplant Nephrotic Syndrome Caused by Recurrent FSGS. J Am Soc Nephrol 2015; 27:2520-7. [PMID: 26701979 DOI: 10.1681/asn.2015091002] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 11/18/2015] [Indexed: 01/05/2023] Open
Abstract
FSGS is a common glomerular disorder that has a high propensity for recurrence after kidney transplant. The pathophysiology of FSGS is unknown, but podocytes seem to be the target of one or several circulating factors that lead to cytoskeleton reorganization and proteinuria. Research on podocytes has identified B7-1 as an important factor in podocyte biology and a new therapeutic target in renal disease. Indeed, in four patients with recurrent FSGS after transplant, treatment with the B7-1 blocker abatacept was associated with proteinuria remission. Here, we prospectively treated nine patients with recurrent FSGS after transplant using either abatacept or belatacept, a B7-1 blocker with higher affinity, and did not induce proteinuria remission. Furthermore, we did not detect B7-1 expression by immunofluorescence in podocytes of biopsy specimens from these or other kidney grafts or podocytes of native kidney biopsy specimens. In conclusion, B7-1 blockade did not induce FSGS remission after transplant in our study.
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Affiliation(s)
- Marianne Delville
- Université Paris Descartes, Sorbonne Paris Cité, Service de Biothérapie
| | - Emilie Baye
- Institut National de la Santé et de la Recherche Médicale U1151, Institut Necker Enfants Malades
| | - Antoine Durrbach
- Service de Néphrologie et Transplantation, Hôpital Bicêtre, Le Kremlin-Bicêtre, Institut National de la Santé et de la Recherche Médicale 1197, Université Paris-Saclay, Le Kremlin Bicêtre, France
| | - Vincent Audard
- Groupe Hospitalier Henri Mondor Albert Chenevier, Service de Néphrologie et Transplantation, Université Paris Est Créteil, Creteil, France
| | - Tomek Kofman
- Groupe Hospitalier Henri Mondor Albert Chenevier, Service de Néphrologie et Transplantation, Université Paris Est Créteil, Creteil, France
| | - Laura Braun
- Service de Néphrologie et Transplantation, Hôpitaux Universitaires de Strasbourg, Nouvel Hôpital Civil, Strasbourg, France
| | - Jérôme Olagne
- Service de Néphrologie et Transplantation, Hôpitaux Universitaires de Strasbourg, Nouvel Hôpital Civil, Strasbourg, France; Laboratoire d'Anatomo-Pathologie, Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, Strasbourg, France
| | - Clément Nguyen
- Institut National de la Santé et de la Recherche Médicale U1151, Institut Necker Enfants Malades
| | - Georges Deschênes
- Service de Néphrologie pédiatrique, Hôpital Robert Debré, Paris, France
| | - Bruno Moulin
- Service de Néphrologie et Transplantation, Hôpitaux Universitaires de Strasbourg, Nouvel Hôpital Civil, Strasbourg, France
| | - Michel Delahousse
- Service de Néphrologie Transplantation, Hôpital Foch, Suresnes, France; and
| | | | - Séverine Beaudreuil
- Service de Néphrologie et Transplantation, Hôpital Bicêtre, Le Kremlin-Bicêtre, Institut National de la Santé et de la Recherche Médicale 1197, Université Paris-Saclay, Le Kremlin Bicêtre, France
| | | | - Marion Rabant
- Service d'Anatomie et Cytologie Pathologiques, Hôpital Necker-Enfants Malades, Paris, France
| | - Philippe Grimbert
- Groupe Hospitalier Henri Mondor Albert Chenevier, Service de Néphrologie et Transplantation, Université Paris Est Créteil, Creteil, France
| | - Morgan Gallazzini
- Université Paris Descartes, Sorbonne Paris Cité, Institut National de la Santé et de la Recherche Médicale U1151, Institut Necker Enfants Malades
| | - Fabiola Terzi
- Université Paris Descartes, Sorbonne Paris Cité, Institut National de la Santé et de la Recherche Médicale U1151, Institut Necker Enfants Malades
| | - Christophe Legendre
- Université Paris Descartes, Sorbonne Paris Cité, Service de Néphrologie Transplantation Adultes, and
| | - Guillaume Canaud
- Université Paris Descartes, Sorbonne Paris Cité, Institut National de la Santé et de la Recherche Médicale U1151, Institut Necker Enfants Malades, Service de Néphrologie Transplantation Adultes, and
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21
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Salant DJ. Podocyte Expression of B7-1/CD80: Is it a Reliable Biomarker for the Treatment of Proteinuric Kidney Diseases with Abatacept? J Am Soc Nephrol 2015; 27:963-5. [PMID: 26400567 DOI: 10.1681/asn.2015080947] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Affiliation(s)
- David J Salant
- Renal Section and Department of Medicine, Boston University Medical Center, Boston, Massachusetts
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22
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Wada T, Nangaku M. A circulating permeability factor in focal segmental glomerulosclerosis: the hunt continues. Clin Kidney J 2015; 8:708-15. [PMID: 26613029 PMCID: PMC4655796 DOI: 10.1093/ckj/sfv090] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 08/11/2015] [Indexed: 01/23/2023] Open
Abstract
Primary focal segmental glomerulosclerosis (FSGS) is one of the major causes of steroid-resistant nephrotic syndrome, and renal prognosis in patients with steroid-resistant FSGS is poor. It has been long speculated that a circulating permeability factor should be implicated in the pathogenesis of the disease because a substantial portion of the patients with primary FSGS experience recurrence shortly after transplantation. Although molecules such as cardiotrophin-like cytokine 1 (CLC-1) and anti-CD40 antibody have been proposed to be potential circulating permeability factors, a definitive factor remains to be discovered. Soluble urokinase-type plasminogen activator receptor (suPAR) has attracted substantial attention and garnered scrutiny by renal researchers since Reiser's group suggested that it was linked to the pathogenesis of primary FSGS and that it might be useful as a diagnostic biomarker. A number of different cohort studies have shown that serum suPAR levels are negatively associated with renal function and can scarcely differentiate FSGS from the other glomerular/renal diseases. In contrast to initial studies, several in vivo studies investigating the effects of forced suPAR upregulation could not show the induction of proteinuria or podocyte injury. Currently it is suggested that a different form of suPAR, which cannot be measured by presently available enzyme-linked immunosorbent assay, might be the culprit; however, it remains to be determined whether this is the case. Because a circulating permeability factor might be a useful biomarker for diagnosing FSGS as well as a potent therapeutic target for primary and recurrent FSGS, further dedicated work will be needed.
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Affiliation(s)
- Takehiko Wada
- Division of Nephrology and Endocrinology , University of Tokyo School of Medicine , Tokyo 113-8655 , Japan
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology , University of Tokyo School of Medicine , Tokyo 113-8655 , Japan
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23
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Gagliardini E, Novelli R, Corna D, Zoja C, Ruggiero B, Benigni A, Remuzzi G. B7-1 Is Not Induced in Podocytes of Human and Experimental Diabetic Nephropathy. J Am Soc Nephrol 2015; 27:999-1005. [PMID: 26319246 DOI: 10.1681/asn.2015030266] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 06/24/2015] [Indexed: 01/13/2023] Open
Abstract
The incidence of progressive kidney disease associated with diabetes continues to rise worldwide. Current standard therapy with angiotensin-converting enzyme inhibitors and/or angiotensin receptor blockers achieves only partial renoprotection, increasing the need for novel therapeutic approaches. Previous studies described B7-1 induction in podocytes of patients with proteinuria, including those with FSGS and type 2 diabetic nephropathy (DN). These findings sparked great excitement in the renal community, implying that abatacept, a costimulatory inhibitor that targets B7-1, could be a novel therapy for diabetic renal disease. Given previous concerns over the value of B7-1 immunostaining and the efficacy of abatacept in patients with recurrent FSGS after renal transplantation, we investigated B7-1 expression in human and experimental DN before embarking on clinical studies of the use of B7-1 targeting strategies to treat proteinuria in DN. Immunohistochemical analysis of kidney specimens using different antibodies revealed that B7-1 is not induced in podocytes of patients with DN, independent of disease stage, or BTBR ob/obmice, a model of type 2 diabetes. These results do not support the use of abatacept as a therapeutic strategy for targeting podocyte B7-1 for the prevention or treatment of DN.
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Affiliation(s)
- Elena Gagliardini
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Rubina Novelli
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Daniela Corna
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Carlamaria Zoja
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Barbara Ruggiero
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Ariela Benigni
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy;
| | - Giuseppe Remuzzi
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy; Unit of Nephrology and Dialysis, Azienda Ospedaliera Papa Giovanni XXIII, Bergamo, Italy; and Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
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24
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Esposito P, Rampino T, Canton AD. Costimulatory blockade: A novel approach to the treatment of glomerular disease? World J Methodol 2015; 5:20-5. [PMID: 26140268 PMCID: PMC4482818 DOI: 10.5662/wjm.v5.i2.20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 04/01/2015] [Accepted: 05/16/2015] [Indexed: 02/06/2023] Open
Abstract
Costimulatory pathways (Cluster of differentiation 28, tumor necrosis factor-related, adhesion and T Cell Ig- and mucin-domain molecules) regulating the interactions between receptors on the T cells and their ligands expressed on several cell types, have a key role in controlling many immunological and non immunological processes. Indeed, accumulating evidence indicate that these molecules are involved in the pathogenesis of numerous conditions, such as allograft rejection, atherosclerosis, rheumatoid arthritis, psoriasis and renal diseases, including glomerulonephritis. Primary or secondary (i.e., associated with infections, drugs or systemic diseases, such as systemic lupus erythematosus, diabetes, etc.) glomerulonephritis represent a group of heterogeneous diseases with different pathogenic mechanisms. Since costimulatory molecules, in particular CD80 and CD40, have been found to be expressed on podocytes in the course of different experimental and clinical glomerulonephritis, costimulation has been thought as a new therapeutic target for patients with glomerular diseases. However, although experimental data suggested that the blockade of costimulatory pathways is effective and safe in the prevention and treatment of glomerular diseases, clinical trials reported contrasting results. So, at this moment, there is not a strong evidence for the general use of costimulatory blockade as an alternative treatment strategy in patients with primary or secondary glomerulonephritis. Here, we critically discuss the current data and the main issues regarding the development of this innovative therapeutic approach.
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25
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The Influence and Role of Microbial Factors in Autoimmune Kidney Diseases: A Systematic Review. J Immunol Res 2015; 2015:858027. [PMID: 26078982 PMCID: PMC4452370 DOI: 10.1155/2015/858027] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 01/26/2015] [Accepted: 02/03/2015] [Indexed: 12/27/2022] Open
Abstract
A better understanding of the pathophysiology of autoimmune disorders is desired to allow tailored interventions. Despite increased scientific interest a direct pathogenic factor in autoimmune renal disease has been described only in a minority like membranous nephropathy or ANCA-associated vasculitis. Nonetheless the initial step leading to the formation of these antibodies is still obscure. In this review we will focus on the possible role of microbial factors in this context. Staphylococcus aureus may be a direct pathogenetic factor in granulomatosis with polyangiitis (GPA). Chronic bacterial colonization or chronic infections of the upper respiratory tract have been proposed as trigger of IgA vasculitis and IgA nephropathy. Interventions to remove major lymphoid organs, such as tonsillectomy, have shown conflicting results but may be an option in IgA vasculitis. Interestingly no clear clinical benefit despite similar local colonization with bacterial strains has been detected in patients with IgA nephropathy. In systemic lupus erythematosus injection of bacterial lipopolysaccharide induced progressive lupus nephritis in mouse models. The aim of this review is to discuss and summarize the knowledge of microbial antigens in autoimmune renal disease. Novel methods may provide insight into the involvement of microbial antigens in the onset, progression, and prognosis of autoimmune kidney disorders.
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26
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Lee HW, Khan SQ, Faridi MH, Wei C, Tardi NJ, Altintas MM, Elshabrawy HA, Mangos S, Quick KL, Sever S, Reiser J, Gupta V. A Podocyte-Based Automated Screening Assay Identifies Protective Small Molecules. J Am Soc Nephrol 2015; 26:2741-52. [PMID: 25858967 DOI: 10.1681/asn.2014090859] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 01/08/2015] [Indexed: 12/30/2022] Open
Abstract
Podocyte injury and loss mark an early step in the pathogenesis of various glomerular diseases, making these cells excellent targets for therapeutics. However, cell-based high-throughput screening assays for the rational development of podocyte-directed therapeutics are currently lacking. Here, we describe a novel high-content screening-based phenotypic assay that analyzes thousands of podocytes per assay condition in 96-well plates to quantitatively measure dose-dependent changes in multiple cellular features. Our assay consistently produced a Z' value >0.44, making it suitable for compound screening. On screening with >2100 pharmacologically active agents, we identified 24 small molecules that protected podocytes against injury in vitro (1% hit rate). Among the identified hits, we confirmed an β1-integrin agonist, pyrintegrin, as a podocyte-protective agent. Treatment with pyrintegrin prevented damage-induced decreases in F-actin stress fibers, focal adhesions, and active β1-integrin levels in cultured cells. In vivo, administration of pyrintegrin protected mice from LPS-induced podocyte foot process effacement and proteinuria. Analysis of the murine glomeruli showed that LPS administration reduced the levels of active β1 integrin in the podocytes, which was prevented by cotreatment with pyrintegrin. In rats, pyrintegrin reduced peak proteinuria caused by puromycin aminonucleoside-induced nephropathy. Our findings identify pyrintegrin as a potential therapeutic candidate and show the use of podocyte-based screening assays for identifying novel therapeutics for proteinuric kidney diseases.
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Affiliation(s)
- Ha Won Lee
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
| | - Samia Q Khan
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
| | - Mohd Hafeez Faridi
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
| | - Changli Wei
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
| | - Nicholas J Tardi
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
| | - Mehmet M Altintas
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
| | - Hatem A Elshabrawy
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
| | - Steve Mangos
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
| | - Kevin L Quick
- Cellular Imaging and Analysis, PerkinElmer Life Sciences, Waltham, Massachusetts; and
| | - Sanja Sever
- Department of Medicine, Harvard Medical School, Division of Nephrology, Massachusetts General Hospital, Charlestown, Massachusetts
| | - Jochen Reiser
- Department of Medicine, Rush University Medical Center, Chicago, Illinois;
| | - Vineet Gupta
- Department of Medicine, Rush University Medical Center, Chicago, Illinois;
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27
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Wei CC, Lin CL, Shen TC, Sung FC. Occurrence of common allergic diseases in children with idiopathic nephrotic syndrome. J Epidemiol 2015; 25:370-7. [PMID: 25843432 PMCID: PMC4411236 DOI: 10.2188/jea.je20140167] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background Clinical and immunological studies have consistently shown a possible link between atopy and idiopathic nephrotic syndrome (INS). However, whether allergic diseases occur after INS develops is unknown. Methods From Taiwan’s National Health Insurance database, 1340 children with newly diagnosed INS and 5360 non-INS matched controls were identified in 2000–2007. By the end of 2008, the incidences and hazard ratios of four allergic diseases (allergic conjunctivitis, allergic rhinitis, atopic dermatitis, and asthma) were calculated. Results The incidence rates of all four allergic diseases were greater in the INS cohort than in the non-INS cohort in all age groups and decreased sharply as age increased in both cohorts. Children with INS had the highest adjusted hazard ratio (4.13; 95% confidence interval [CI], 2.50–6.83) for atopic dermatitis and the lowest adjusted hazard ratio (1.71; 95% CI, 1.39–2.09) for allergic rhinitis. Most of the allergic diseases appeared within 2–6 months after INS developed, and the incidences declined with increasing follow-up duration. Conclusions Allergic disorders are common in children with INS, especially within the first year after diagnosis. The role of INS in the development of allergic disorders should be elucidated to establish innovative disease intervention programs.
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Affiliation(s)
- Chang-Ching Wei
- Children's Hospital, China Medical University Hospital; College of Medicine China Medical University, Taichung, Taiwan
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28
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Saleem MA. One hundred ways to kill a podocyte. Nephrol Dial Transplant 2015; 30:1266-71. [PMID: 25637640 DOI: 10.1093/ndt/gfu363] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 10/27/2014] [Indexed: 12/30/2022] Open
Abstract
The podocyte is a highly specialized cell, forming within the developing glomerulus from a mesenchymal origin, acquiring some but not complete features of an epithelial cell as it matures. Once mature, this cell has the potential to receive signals from several different directions and sits within a dynamic microenvironment. By taking an overview of many lines of evidence, it is clear that we already know many signals that are tightly controlled in keeping the podocyte healthy. For example, vascular endothelial growth factor, insulin and integrins are all known to have bidirectional effects on podocyte functionality, depending on whether there is too much or too little. It is of little surprise therefore that disrupting this delicate balance can result in a dramatic loss of function, and manifestation of glomerular disease originating from many different primary insults. The cues directing podocyte phenotype and functionality for the purpose of this review will be divided into four main sources: (i) genetic, (ii) paracrine signals from endothelial and mesangial cells, (iii) direct contact signals to/from the glomerular basement membrane and (iv) signals from circulating plasma. Of course there are other influences, which we still know little about, such as flow and shear stresses, signals from the urinary space that should all be considered in the overall healthy environment.
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Affiliation(s)
- Moin A Saleem
- Bristol Children's Hospital, University of Bristol, Bristol, UK
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29
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Ravani P, Rossi R, Bonanni A, Quinn RR, Sica F, Bodria M, Pasini A, Montini G, Edefonti A, Belingheri M, De Giovanni D, Barbano G, Degl'Innocenti L, Scolari F, Murer L, Reiser J, Fornoni A, Ghiggeri GM. Rituximab in Children with Steroid-Dependent Nephrotic Syndrome: A Multicenter, Open-Label, Noninferiority, Randomized Controlled Trial. J Am Soc Nephrol 2015; 26:2259-66. [PMID: 25592855 DOI: 10.1681/asn.2014080799] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 11/18/2014] [Indexed: 01/03/2023] Open
Abstract
Steroid-dependent nephrotic syndrome (SDNS) carries a high risk of toxicity from steroids or steroid-sparing agents. This open-label, noninferiority, randomized controlled trial at four sites in Italy tested whether rituximab is noninferior to steroids in maintaining remission in juvenile SDNS. We enrolled children age 1-16 years who had developed SDNS in the previous 6-12 months and were maintained in remission with high prednisone doses (≥0.7 mg/kg per day). We randomly assigned participants to continue prednisone alone for 1 month (control) or to add a single intravenous infusion of rituximab (375 mg/m(2); intervention). Prednisone was tapered in both groups after 1 month. For noninferiority, rituximab had to permit steroid withdrawal and maintain 3-month proteinuria (mg/m(2) per day) within a prespecified noninferiority margin of three times the levels among controls (primary outcome). We followed participants for ≥1 year to compare risk of relapse (secondary outcome). Fifteen children per group (21 boys; mean age, 7 years [range, 2.6-13.5 years]) were enrolled and followed for ≤60 months (median, 22 months). Three-month proteinuria was 42% lower in the rituximab group (geometric mean ratio, 0.58; 95% confidence interval, 0.18 to 1.95 [i.e., within the noninferiority margin of three times the levels in controls]). All but one child in the control group relapsed within 6 months; median time to relapse in the rituximab group was 18 months (95% confidence interval, 9 to 32 months). In the rituximab group, nausea and skin rash during infusion were common; transient acute arthritis occurred in one child. In conclusion, rituximab was noninferior to steroids for the treatment of juvenile SDNS.
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Affiliation(s)
- Pietro Ravani
- Division of Nephrology, University of Calgary, Calgary, Alberta, Canada;
| | - Roberta Rossi
- Division of Nephrology, Dialysis, Transplantation, Giannina Gaslini Children's Hospital, Genoa, Italy
| | - Alice Bonanni
- Division of Nephrology, Dialysis, Transplantation, Giannina Gaslini Children's Hospital, Genoa, Italy
| | - Robert R Quinn
- Division of Nephrology, University of Calgary, Calgary, Alberta, Canada
| | - Felice Sica
- Division of Pediatrics, Hospital of Foggia, Foggia, Italy
| | - Monica Bodria
- Division of Nephrology, Dialysis, Transplantation, Giannina Gaslini Children's Hospital, Genoa, Italy
| | - Andrea Pasini
- Nephrology and Pediatric Dialysis, Department of Pediatrics, Azienda Ospedaliera Universitaria Sant'Orsola, Bologna, Italy
| | - Giovanni Montini
- Nephrology and Pediatric Dialysis, Department of Pediatrics, Azienda Ospedaliera Universitaria Sant'Orsola, Bologna, Italy
| | - Alberto Edefonti
- Pediatric Nephrology and Dialysis Unit, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Mirco Belingheri
- Pediatric Nephrology and Dialysis Unit, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | | | - Giancarlo Barbano
- Division of Nephrology, Dialysis, Transplantation, Giannina Gaslini Children's Hospital, Genoa, Italy
| | - Ludovica Degl'Innocenti
- Division of Nephrology, Dialysis, Transplantation, Giannina Gaslini Children's Hospital, Genoa, Italy
| | - Francesco Scolari
- Division of Nephrology and Dialysis, Ospedale di Montichiari Azienda Ospedaliera Spedali Civili di Brescia, Brescia, Italy
| | - Luisa Murer
- Pediatric Nephrology, Dialysis and Transplant Unit, Department of Pediatrics, University Hospital of Padua, Padua, Italy
| | - Jochen Reiser
- Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois; and
| | - Alessia Fornoni
- Miller School of Medicine, University of Miami, Miami, Florida
| | - Gian Marco Ghiggeri
- Division of Nephrology, Dialysis, Transplantation, Giannina Gaslini Children's Hospital, Genoa, Italy
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30
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Lazzeri E, Ronconi E, Angelotti ML, Peired A, Mazzinghi B, Becherucci F, Conti S, Sansavini G, Sisti A, Ravaglia F, Lombardi D, Provenzano A, Manonelles A, Cruzado JM, Giglio S, Roperto RM, Materassi M, Lasagni L, Romagnani P. Human Urine-Derived Renal Progenitors for Personalized Modeling of Genetic Kidney Disorders. J Am Soc Nephrol 2015; 26:1961-74. [PMID: 25568173 DOI: 10.1681/asn.2014010057] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 09/30/2014] [Indexed: 12/16/2022] Open
Abstract
The critical role of genetic and epigenetic factors in the pathogenesis of kidney disorders is gradually becoming clear, and the need for disease models that recapitulate human kidney disorders in a personalized manner is paramount. In this study, we describe a method to select and amplify renal progenitor cultures from the urine of patients with kidney disorders. Urine-derived human renal progenitors exhibited phenotype and functional properties identical to those purified from kidney tissue, including the capacity to differentiate into tubular cells and podocytes, as demonstrated by confocal microscopy, Western blot analysis of podocyte-specific proteins, and scanning electron microscopy. Lineage tracing studies performed with conditional transgenic mice, in which podocytes are irreversibly tagged upon tamoxifen treatment (NPHS2.iCreER;mT/mG), that were subjected to doxorubicin nephropathy demonstrated that renal progenitors are the only urinary cell population that can be amplified in long-term culture. To validate the use of these cells for personalized modeling of kidney disorders, renal progenitors were obtained from (1) the urine of children with nephrotic syndrome and carrying potentially pathogenic mutations in genes encoding for podocyte proteins and (2) the urine of children without genetic alterations, as validated by next-generation sequencing. Renal progenitors obtained from patients carrying pathogenic mutations generated podocytes that exhibited an abnormal cytoskeleton structure and functional abnormalities compared with those obtained from patients with proteinuria but without genetic mutations. The results of this study demonstrate that urine-derived patient-specific renal progenitor cultures may be an innovative research tool for modeling of genetic kidney disorders.
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Affiliation(s)
- Elena Lazzeri
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE) and
| | - Elisa Ronconi
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE) and Department of Clinical and Experimental Biomedical Sciences, University of Florence, Florence, Italy
| | - Maria Lucia Angelotti
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE) and
| | - Anna Peired
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE) and Department of Clinical and Experimental Biomedical Sciences, University of Florence, Florence, Italy
| | | | - Francesca Becherucci
- Pediatric Nephrology Unit, Meyer Children's University Hospital, Florence, Italy
| | - Sara Conti
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Centro Anna Maria Astori, Bergamo, Italy; and
| | - Giulia Sansavini
- Pediatric Nephrology Unit, Meyer Children's University Hospital, Florence, Italy
| | - Alessandro Sisti
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE) and
| | - Fiammetta Ravaglia
- Pediatric Nephrology Unit, Meyer Children's University Hospital, Florence, Italy
| | - Duccio Lombardi
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE) and
| | | | - Anna Manonelles
- Department of Nephrology, Bellvitge's University Hospital, Barcelona, Spain
| | - Josep M Cruzado
- Department of Nephrology, Bellvitge's University Hospital, Barcelona, Spain
| | - Sabrina Giglio
- Department of Clinical and Experimental Biomedical Sciences, University of Florence, Florence, Italy; Medical Genetics Unit and
| | - Rosa Maria Roperto
- Pediatric Nephrology Unit, Meyer Children's University Hospital, Florence, Italy
| | - Marco Materassi
- Pediatric Nephrology Unit, Meyer Children's University Hospital, Florence, Italy
| | - Laura Lasagni
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE) and
| | - Paola Romagnani
- Excellence Centre for Research, Transfer and High Education for the Development of DE NOVO Therapies (DENOTHE) and Department of Clinical and Experimental Biomedical Sciences, University of Florence, Florence, Italy; Pediatric Nephrology Unit, Meyer Children's University Hospital, Florence, Italy;
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31
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Sakamoto K, Kuno K, Takemoto M, He P, Ishikawa T, Onishi S, Ishibashi R, Okabe E, Shoji M, Hattori A, Yamaga M, Kobayashi K, Kawamura H, Tokuyama H, Maezawa Y, Yokote K. Pituitary adenylate cyclase-activating polypeptide protects glomerular podocytes from inflammatory injuries. J Diabetes Res 2015; 2015:727152. [PMID: 25821833 PMCID: PMC4363873 DOI: 10.1155/2015/727152] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 01/15/2015] [Accepted: 01/19/2015] [Indexed: 12/02/2022] Open
Abstract
Diabetic nephropathy (DN) is a leading cause of end-stage kidney disease; however, there are few treatment options. Inflammation plays a crucial role in the initiation and/or progression of DN. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide, which was originally isolated from the ovine hypothalamus and reportedly has diverse biological functions. It has been reported that PACAP has renoprotective effects in different models of kidney pathology. However, the specific cell types within the kidney that are protected by PACAP have not yet been reported. In this study, we localized VPAC1, one of the PACAP receptors, to glomerular podocytes, which also reportedly has crucial roles not only in glomerular physiology but also in pathology. PACAP was effective in the downregulation of proinflammatory cytokines, such as monocyte chemoattractant protein-1 (MCP-1) and interleukin-6, which had been induced by the activation of toll-like receptor (TLR) with lipopolysaccharide. PACAP also had downregulated the expression of MCP-1 through the protein kinase A signaling pathway; this led to the attenuation of the activation of extracellular signal-regulated kinase and nuclear factor-kappa B signaling. Our results suggested that PACAP could be a possible treatment option for DN through the use of anti-inflammation effects on glomerular podocytes.
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Affiliation(s)
- Kenichi Sakamoto
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
- Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Japan
| | - Kyoko Kuno
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
| | - Minoru Takemoto
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
- Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Japan
- *Minoru Takemoto:
| | - Peng He
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
| | - Takahiro Ishikawa
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
- Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Japan
| | - Shunichiro Onishi
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
- Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Japan
| | - Ryoichi Ishibashi
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
- Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Japan
| | - Emiko Okabe
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
- Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Japan
| | - Mayumi Shoji
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
- Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Japan
| | - Akiko Hattori
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
- Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Japan
| | - Masaya Yamaga
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
- Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Japan
| | - Kazuki Kobayashi
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
- Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Japan
| | - Harukiyo Kawamura
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
- Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Japan
| | - Hirotake Tokuyama
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
- Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Japan
| | - Yoshiro Maezawa
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
- Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Japan
| | - Koutaro Yokote
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, Japan
- Division of Diabetes, Metabolism and Endocrinology, Chiba University Hospital, Japan
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Hato T, Dagher PC. How the Innate Immune System Senses Trouble and Causes Trouble. Clin J Am Soc Nephrol 2014; 10:1459-69. [PMID: 25414319 DOI: 10.2215/cjn.04680514] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The innate immune system is the first line of defense in response to nonself and danger signals from microbial invasion or tissue injury. It is increasingly recognized that each organ uses unique sets of cells and molecules that orchestrate regional innate immunity. The cells that execute the task of innate immunity are many and consist of not only "professional" immune cells but also nonimmune cells, such as renal epithelial cells. Despite a high level of sophistication, deregulated innate immunity is common and contributes to a wide range of renal diseases, such as sepsis-induced kidney injury, GN, and allograft dysfunction. This review discusses how the innate immune system recognizes and responds to nonself and danger signals. In particular, the roles of renal epithelial cells that make them an integral part of the innate immune apparatus of the kidney are highlighted.
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Affiliation(s)
- Takashi Hato
- Department of Medicine, Indiana University, Indianapolis, Indiana
| | - Pierre C Dagher
- Department of Medicine, Indiana University, Indianapolis, Indiana
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33
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Schlondorff J. How many Achilles' heels does a podocyte have? An update on podocyte biology: Table 1. Nephrol Dial Transplant 2014; 30:1091-7. [DOI: 10.1093/ndt/gfu214] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 05/07/2014] [Indexed: 11/15/2022] Open
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34
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Ponticelli C, Moroni G, Glassock RJ. De novo glomerular diseases after renal transplantation. Clin J Am Soc Nephrol 2014; 9:1479-87. [PMID: 24700797 DOI: 10.2215/cjn.12571213] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Glomerular diseases developing in the kidney allograft are more often recurrences of the original disease affecting the native kidneys. However, in an undefined number of cases de novo, glomerular diseases unrelated to the original disease in the native kidneys can develop in the transplanted kidney. The clinical presentation and histologic features of de novo diseases are often similar to those features observed in patients with primary or secondary GN in the native kidneys. However, in transplanted kidneys, the glomerular, vascular, and tubulointerstitial changes are often intertwined with structural abnormalities already present at the time of transplant or caused by antibody- or cell-mediated allograft rejection, immunosuppressive drugs, or superimposed infection (most often of a viral nature). The pathophysiology of de novo glomerular diseases is quite variable. In rare cases of de novo minimal change disease, circulating factors increasing the glomerular permeability likely participate. Maladaptive hemodynamic changes and tissue fibrosis caused by calcineurin inhibitors or other factors may be involved in the pathogenesis of de novo FSGS. The exposure of cryptic podocyte antigens may favor the development of de novo membranous nephropathy. Many cases of de novo membranoproliferative GN are related to hepatitis C virus infection. Patients with Alport syndrome lacking antigenic epitopes in their glomerular basement membrane may develop antibodies against these glomerular basement membrane antigens expressed in the transplanted kidney. Infection may cause acute GN to have a heterogeneous clinical presentation and outcome. De novo pauci-immune GN in renal transplant is rare. Preexisting or acquired intolerance to glucose may, in the long term, cause diabetic nephropathy. The prognosis of de novo diseases depends on the type of GN, the severity of lesions caused by the alloimmune response, or the efficacy of immunosuppressive therapy. In most cases, the management of de novo glomerular diseases is empirical or elusive.
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Affiliation(s)
- Claudio Ponticelli
- Division of Nephrology, Humanitas Scientific Institute, Rozzano, Milan, Italy;
| | - Gabriella Moroni
- Division of Nephrology, Fondazione Ca' Granda Ospedale Maggiore Istituto Scientifico, Milan, Italy; and
| | - Richard J Glassock
- Department of Medicine, Geffen School of Medicine at the University of California at Los Angeles, Laguna Niguel, California
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35
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Fiorina P, Vergani A, Bassi R, Niewczas MA, Altintas MM, Pezzolesi MG, D'Addio F, Chin M, Tezza S, Ben Nasr M, Mattinzoli D, Ikehata M, Corradi D, Schumacher V, Buvall L, Yu CC, Chang JM, La Rosa S, Finzi G, Solini A, Vincenti F, Rastaldi MP, Reiser J, Krolewski AS, Mundel PH, Sayegh MH. Role of podocyte B7-1 in diabetic nephropathy. J Am Soc Nephrol 2014; 25:1415-29. [PMID: 24676639 DOI: 10.1681/asn.2013050518] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Podocyte injury and resulting albuminuria are hallmarks of diabetic nephropathy, but targeted therapies to halt or prevent these complications are currently not available. Here, we show that the immune-related molecule B7-1/CD80 is a critical mediator of podocyte injury in type 2 diabetic nephropathy. We report the induction of podocyte B7-1 in kidney biopsy specimens from patients with type 2 diabetes. Genetic and epidemiologic studies revealed the association of two single nucleotide polymorphisms at the B7-1 gene with diabetic nephropathy. Furthermore, increased levels of the soluble isoform of the B7-1 ligand CD28 correlated with the progression to ESRD in individuals with type 2 diabetes. In vitro, high glucose conditions prompted the phosphatidylinositol 3 kinase-dependent upregulation of B7-1 in podocytes, and the ectopic expression of B7-1 in podocytes increased apoptosis and induced disruption of the cytoskeleton that were reversed by the B7-1 inhibitor CTLA4-Ig. Podocyte expression of B7-1 was also induced in vivo in two murine models of diabetic nephropathy, and treatment with CTLA4-Ig prevented increased urinary albumin excretion and improved kidney pathology in these animals. Taken together, these results identify B7-1 inhibition as a potential therapeutic strategy for the prevention or treatment of diabetic nephropathy.
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Affiliation(s)
- Paolo Fiorina
- Nephrology Division, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts; Department of Medicine, San Raffaele Scientific Institute, Milan, Italy;
| | - Andrea Vergani
- Nephrology Division, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts; Department of Medicine, San Raffaele Scientific Institute, Milan, Italy
| | - Roberto Bassi
- Nephrology Division, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts; Department of Medicine, San Raffaele Scientific Institute, Milan, Italy; DiSTeBA, Universita' del Salento, Lecce, Italy
| | - Monika A Niewczas
- Section on Genetics and Epidemiology, Research Division, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Mehmet M Altintas
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
| | - Marcus G Pezzolesi
- Section on Genetics and Epidemiology, Research Division, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Francesca D'Addio
- Nephrology Division, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts; Department of Medicine, San Raffaele Scientific Institute, Milan, Italy
| | - Melissa Chin
- Nephrology Division, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Sara Tezza
- Nephrology Division, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Moufida Ben Nasr
- Nephrology Division, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Deborah Mattinzoli
- Renal Research Laboratory, Fondazione IRCCS Ospedale Maggiore Policlinico and Fondazione D'Amico per la Ricerca sulle Malattie Renali, Milan, Italy
| | - Masami Ikehata
- Renal Research Laboratory, Fondazione IRCCS Ospedale Maggiore Policlinico and Fondazione D'Amico per la Ricerca sulle Malattie Renali, Milan, Italy
| | - Domenico Corradi
- Department of Biomedical, Biotechnological and Translational Sciences, Unit of Pathology, University of Parma, Parma, Italy
| | - Valerie Schumacher
- Nephrology Division, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Lisa Buvall
- Nephrology Division, Massachusetts General Hospital, Boston, Massachusetts
| | - Chih-Chuan Yu
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Internal Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Jer-Ming Chang
- Department of Internal Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | | | - Giovanna Finzi
- Pathology Department, Ospedale di Circolo, Varese, Italy
| | - Anna Solini
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Flavio Vincenti
- Kidney Transplant Service, University of San Francisco, San Francisco, California
| | - Maria Pia Rastaldi
- Renal Research Laboratory, Fondazione IRCCS Ospedale Maggiore Policlinico and Fondazione D'Amico per la Ricerca sulle Malattie Renali, Milan, Italy
| | - Jochen Reiser
- Department of Medicine, Rush University Medical Center, Chicago, Illinois
| | - Andrzej S Krolewski
- Section on Genetics and Epidemiology, Research Division, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Peter H Mundel
- Nephrology Division, Massachusetts General Hospital, Boston, Massachusetts
| | - Mohamed H Sayegh
- Transplantation Research Center, Brigham and Women's Hospital, Boston, Massachusetts; and American University of Beirut, Beirut, Lebanon
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Sethi S, Glassock RJ, Fervenza FC. Focal segmental glomerulosclerosis: towards a better understanding for the practicing nephrologist. Nephrol Dial Transplant 2014; 30:375-84. [PMID: 24589721 DOI: 10.1093/ndt/gfu035] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Focal and segmental glomerulosclerosis (FSGS) is a common histopathological lesion that can represent a primary podocytopathy, or occur as an adaptive phenomenon consequent to nephron mass reduction, a scar from a healing vasculitic lesion, direct drug toxicity or viral infection among other secondary causes. Thus, the presence of an FSGS lesion in a renal biopsy does not confer a disease diagnosis, but rather represents the beginning of an exploratory process, hopefully leading ultimately to identification of a specific etiology and its appropriate treatment. We define primary FSGS as a 'primary' podocytopathy characterized clinically by the presence of nephrotic syndrome in a patient with an FSGS lesion on light microscopy and widespread foot process effacement on electron microscopy (EM). Secondary FSGS is commonly characterized by the absence of nephrotic syndrome and the presence of segmental foot process effacement on EM. Failure to accurately differentiate between the primary and secondary forms of FSGS has resulted in many patients undergoing unnecessary immunosuppressive treatment. Here, we review some key points that may assist the practicing nephrologist to distinguish between primary and secondary FSGS.
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Affiliation(s)
- Sanjeev Sethi
- Division of Anatomic Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | | | - Fernando C Fervenza
- Division of Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, MN, USA
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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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38
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O’Neill AC, Ricardo SD. Human kidney cell reprogramming: applications for disease modeling and personalized medicine. J Am Soc Nephrol 2013; 24:1347-56. [PMID: 23949797 PMCID: PMC3752950 DOI: 10.1681/asn.2012121199] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The ability to reprogram fully differentiated cells into a pluripotent embryonic state, termed induced pluripotent stem cells (iPSCs), has been met with great excitement. iPSC technology has advanced the fundamental study of disease modeling with the potential for cell-replacement therapy, especially in the neuronal and cardiac fields. However, renal medicine as of yet has not benefited from similar advancements. This review summarizes the unique characteristics of iPSCs and their potential applications for modeling kidney disease. Pioneering such endeavors could yield constructs that recapitulate disease phenotypes, open avenues for more targeted drug development, and potentially serve as replenishable sources for replacement of kidney cells in the setting of human disease.
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Affiliation(s)
- Adam C. O’Neill
- Department of Pediatrics, Dunedin School of Medicine, Otago University, Dunedin, New Zealand, and
| | - Sharon D. Ricardo
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
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Goldwich A, Burkard M, Olke M, Daniel C, Amann K, Hugo C, Kurts C, Steinkasserer A, Gessner A. Podocytes are nonhematopoietic professional antigen-presenting cells. J Am Soc Nephrol 2013; 24:906-16. [PMID: 23539760 DOI: 10.1681/asn.2012020133] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Podocytes are essential to the structure and function of the glomerular filtration barrier; however, they also exhibit increased expression of MHC class II molecules under inflammatory conditions, and they remove Ig and immune complexes from the glomerular basement membrane (GBM). This finding suggests that podocytes may act as antigen-presenting cells, taking up and processing antigens to initiate specific T cell responses, similar to professional hematopoietic cells such as dendritic cells or macrophages. Here, MHC-antigen complexes expressed exclusively on podocytes of transgenic mice were sufficient to activate CD8+ T cells in vivo. In addition, deleting MHC class II exclusively on podocytes prevented the induction of experimental anti-GBM nephritis. Podocytes ingested soluble and particulate antigens, activated CD4+ T cells, and crosspresented exogenous antigen on MHC class I molecules to CD8+ T cells. In conclusion, podocytes participate in the antigen-specific activation of adaptive immune responses, providing a potential target for immunotherapies of inflammatory kidney diseases and transplant rejection.
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Affiliation(s)
- Andreas Goldwich
- Department of Immunemodulation at the Dermatology, University Hospital Erlangen, Erlangen, Germany.
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Hogan J, Radhakrishnan J. The treatment of minimal change disease in adults. J Am Soc Nephrol 2013; 24:702-11. [PMID: 23431071 DOI: 10.1681/asn.2012070734] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Minimal change disease (MCD) is the etiology of 10%-25% of cases of nephrotic syndrome in adults. The mainstay of treatment for adult MCD, oral glucocorticoids, is based on two randomized controlled trials and extensive observational data in adults, and this treatment leads to remission in over 80% of cases. Relapses are common, and some patients become steroid-resistant (SR), steroid-dependent (SD), or frequently relapsing (FR). The data guiding the treatment of these patients are limited. Here, we review MCD in adults with particular focus on the evidence for immunosuppressive therapy in these patients.
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Affiliation(s)
- Jonathan Hogan
- Columbia University Medical Center-Internal Medicine, Division of Nephrology, 622 West 168th Street, PH 4-124, New York, NY 10025, USA
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Ao Q, Cheng Q, Ma Q, Wang X, Liu S. Inhibition of calcium(2+)/calmodulin-dependent protein kinase type IV ameliorates experimental nephrotic syndrome. Intern Med 2013; 52:1035-41. [PMID: 23676587 DOI: 10.2169/internalmedicine.52.9574] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVE Evidence has demonstrated that Ca(2+)/calmodulin-dependent protein kinase type IV (CaMKIV) contributes to altered cytokine production by promoting the production of inflammatory cytokines. This study aimed to explore the protective role and underlying mechanisms of CaMKIV inhibition in experimental nephrotic syndrome. METHODS BALB/c mice received single intravenous injections of adriamycin (10 mg/kg) then were sacrificed at two, four and six weeks. In the second study, treatment with KN-93, a CaMKIV inhibitor, or vehicle administered via intraperitoneal injection was started five days after adriamycin injection. Functional and pathologic parameters, the presence of inflammatory infiltration and the expressions of pro-inflammatory cytokines were assessed. RESULTS The CaMKIV protein expression levels were upregulated in the mice with adriamycin nephropathy, which was significantly inhibited by KN-93 (p<0.01). As compared with the vehicle-treated controls, KN-93 treatment resulted in marked suppression of proteinuria and serum creatinine at week 6 (p<0.01), but not at two weeks after induction of the disease. KN-93 inhibited glomerulosclerosis and the development of tubulointerstitial lesions. The renal alpha-smooth muscle actin (α-SMA) expression was also significantly suppressed by KN-93 treatment at week 6 (p<0.01). Moreover, KN-93 inhibited the renal monocyte chemoattractant protein-1 (MCP-1) expression, paralleled by a reduction in the interstitial infiltration of macrophages and T-cells (p<0.01). CONCLUSION Our findings suggest that activation of CaMKIV signaling is involved in the progression of glomerular diseases with a proteinuric state. Our data therefore justify the development of small molecule CaMKIV inhibitors for the treatment of clinical nephrotic syndrome.
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Affiliation(s)
- Qiangguo Ao
- Department of Geriatric Nephrology, Institute of Gerontology, Chinese PLA General Hospital, China
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42
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Ishimoto T, Shimada M, Gabriela G, Kosugi T, Sato W, Lee PY, Lanaspa MA, Rivard C, Maruyama S, Garin EH, Johnson RJ. Toll-like receptor 3 ligand, polyIC, induces proteinuria and glomerular CD80, and increases urinary CD80 in mice. Nephrol Dial Transplant 2012; 28:1439-46. [PMID: 23262434 DOI: 10.1093/ndt/gfs543] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND We have reported that children with biopsy-proven minimal change disease (MCD) express CD80 (also known as B7.1) in their podocytes and excrete high levels of CD80 in their urine during active nephrotic syndrome. We also reported that polyIC, a Toll-like receptor 3 ligand, increases CD80 mRNA and protein expression in cultured human podocytes dose-dependently, with actin re-organization and a reduction in synaptopodin expression. METHODS To determine the effect of polyIC in the kidney, we subjected mice to systemic injection of polyIC or phosphate buffered saline. RESULTS Mice injected with polyIC developed significant proteinuria with increased urinary CD80 excretion. Glomeruli from mice injected with polyIC were normal by light microscopic examination, but showed increased CD80 production in podocytes by immunofluorescence staining. In isolated glomeruli from mice injected with polyIC, expressions of CD80 and interleukin 10 significantly increased with a mild non-significant increase in CTLA-4, and synaptopodin expression decreased significantly. CONCLUSIONS Our study demonstrates that systemically administered polyIC can induce transient proteinuria and urinary CD80 excretion with an increase in CD80 production in podocytes, increased glomerular CD80 and reduced synaptopodin expression. These findings may be relevant to the pathogenesis of proteinuria in MCD.
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Affiliation(s)
- Takuji Ishimoto
- Division of Renal diseases and Hypertension, University of Colorado Denver, Aurora, CO, USA.
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Koya M, Pichler R, Jefferson JA. Minimal-change disease secondary to etanercept. Clin Kidney J 2012; 5:420-3. [PMID: 26019819 PMCID: PMC4432405 DOI: 10.1093/ckj/sfs081] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 06/18/2012] [Indexed: 01/15/2023] Open
Abstract
Etanercept is a soluble tumor necrosis factor alpha (TNFα) receptor which is widely used in the treatment of rheumatoid arthritis, psoriasis and other autoimmune inflammatory disorders. It is known for its relative lack of nephrotoxicity; however, there are reports on the development of nephrotic syndrome associated with the treatment with TNFα antagonists. Here, we describe a patient with psoriasis who developed biopsy-proven minimal-change disease (MCD) shortly after initiating etanercept. Our case is unique in that the MCD resolved after discontinuation of this medication, notably without the use of corticosteroids, strongly suggesting a drug-related phenomenon.
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Affiliation(s)
- Mariko Koya
- Department of Internal Medicine , University of Washington , Seattle, WA , USA
| | - Raimund Pichler
- Department of Nephrology , University of Washington , Seattle, WA , USA
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Is the antiproteinuric effect of cyclosporine a independent of its immunosuppressive function in T cells? Int J Nephrol 2012; 2012:809456. [PMID: 22778954 PMCID: PMC3384901 DOI: 10.1155/2012/809456] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 04/20/2012] [Accepted: 05/03/2012] [Indexed: 12/21/2022] Open
Abstract
The antiproteinuric effect of cyclosporine A(CsA) has been believed to result from its immunosuppressive effect on the transcription factor NFAT in T cells. However, current evidences supporting this hypothesis are missing. A recent study showed that CsA has a direct antiproteinuric effect on podocytes, suggesting a novel non-immunosuppressive mechanism for CsA's antiproteinuric effect. Conditional NFATc1 activation in podoyctes per se is sufficient to induce proteinuria in mice, indicating that NFAT activation in podocytes is a critical pathogenic molecular event leading to podocyte injury and proteinuria. Meanwhile, evidence showed that TRPC6-mediated Ca(2+) influx stimulates NFAT-dependent TRPC6 expression. Altogether, these advances in podocyte research indicate that calcineurin-NFAT signal or calcineurin-synaptopodin axis has a direct proteinuric effect on podocytes which raises the possibility of developing specific antiproteinuric drugs that lack the unwanted effects of calcineurin or NFAT inhibition.
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Coppo R, Camilla R, Porcellini MG, Peruzzi L, Gianoglio B, Amore A, Daprà V, Loiacono E, Fonsato V, Dal Canton A, Esposito C, Esposito P, Tovo PA. Saquinavir in steroid-dependent and -resistant nephrotic syndrome: a pilot study. Nephrol Dial Transplant 2012; 27:1902-10. [PMID: 22431705 DOI: 10.1093/ndt/gfs035] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Some difficult cases of idiopathic nephrotic syndrome (NS) have been treated with a HIV protease inhibitor provided with proteasome-inhibiting activity. The objective of this study was to limit nuclear factor κB (NF-κB) activation which is up-regulated in these patients, aiming at decreasing proteinuria and prednisone need. METHODS Ten cases with long-lasting (up to 15 years) history of NS with steroid dependence (six cases, of which three with secondary steroid resistance) or resistance to steroids (four cases) unsuccessfully treated with multiple immunosuppressive drugs, accepted a treatment with the protease inhibitor saquinavir. p50/p65 NF-κB nuclear localization and immunoproteasome/proteasome messenger RNA (mRNA) were monitored in peripheral blood mononuclear cells (PBMCs). The effects of saquinavir on NF-κB nuclear localization in cultured PBMCs and in immortalized human podocytes were assessed. RESULTS After a median follow-up of 14.7 months (6-68.7), 1/4 primary steroid-resistant NS (SRNS) and 5/6 steroid-dependent NS or secondary SRNS became infrequent (5) or frequent (1) relapsers, with 63% prednisone reduction (from 25.3 to 8.4 mg/kg/month, P = 0.015). Saquinavir was effective in association with low doses of calcineurin inhibitors (cyclosporine 2 mg/kg/day or tacrolimus 0.01-0.06 mg/kg/day). No side effects were observed apart from transitory mild diarrhoea. In PBMCs, NF-κB was down-regulated, while MECL-1 immunoproteasome/beta2 proteasome mRNA ratio was reversed to normal values. In culture, saquinavir blunted NF-κB activation in human podocytes and in PBMCs. CONCLUSIONS In this pilot study, a HIV antiprotease drug reduced proteinuria and had a steroid-sparing effect in some multidrug-resistant/-dependent NS. This observation warrants further investigation.
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Affiliation(s)
- Rosanna Coppo
- Nephrology, Dialysis and Transplantation Unit, Regina Margherita University Hospital, Turin, Italy.
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Minimal-Change Disease Secondary to Borrelia burgdorferi Infection. Case Rep Nephrol 2012; 2012:294532. [PMID: 24527240 PMCID: PMC3914252 DOI: 10.1155/2012/294532] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 01/26/2012] [Indexed: 11/17/2022] Open
Abstract
Lyme borreliosis is a chronic illness caused by tick-transmitted spirochete Borrelia burgdorferi. Borreliosis can be extremely threatening if it is not diagnosed and treated in early stages. Kidneys are not typically involved in the disease. However, in infected dogs, Lyme nephritis is present in 5–10% of cases. It is associated with rapidly progressing renal failure. Histopathological examination shows mesangial proliferative glomerulonephritis with diffuse tubular necrosis, (Dambach et al. (1997)). In available literature, there were reports of human's glomerulonephritis associated with Borrelia burgdorferi infection. These cases refer to membranous and mesangial proliferative glomerulonephritis (Kirmizis and Chatzidimitriou (2010), Zachäus (2008), and Kirmizis et al. (2004)). In this paper, we present the case of minimal-change disease (MCD) as a result of Borrelia burgdorferi infection.
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Couser WG. Basic and translational concepts of immune-mediated glomerular diseases. J Am Soc Nephrol 2012; 23:381-99. [PMID: 22282593 DOI: 10.1681/asn.2011030304] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Genetically modified immune responses to infections and self-antigens initiate most forms of GN by generating pathogen- and danger-associated molecular patterns that stimulate Toll-like receptors and complement. These innate immune responses activate circulating monocytes and resident glomerular cells to release inflammatory mediators and initiate adaptive, antigen-specific immune responses that collectively damage glomerular structures. CD4 T cells are needed for B cell-driven antibody production that leads to immune complex formation in glomeruli, complement activation, and injury induced by both circulating inflammatory and resident glomerular effector cells. Th17 cells can also induce glomerular injury directly. In this review, information derived from studies in vitro, well characterized experimental models, and humans summarize and update likely pathogenic mechanisms involved in human diseases presenting as nephritis (postinfectious GN, IgA nephropathy, antiglomerular basement membrane and antineutrophil cytoplasmic antibody-mediated crescentic GN, lupus nephritis, type I membranoproliferative GN), and nephrotic syndrome (minimal change/FSGS, membranous nephropathy, and C3 glomerulopathies). Advances in understanding the immunopathogenesis of each of these entities offer many opportunities for future therapeutic interventions.
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Affiliation(s)
- William G Couser
- Division of Nephrology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA.
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Zhang B, Xie S, Shi W, Yang Y. Amiloride off-target effect inhibits podocyte urokinase receptor expression and reduces proteinuria. Nephrol Dial Transplant 2011; 27:1746-55. [PMID: 22076430 DOI: 10.1093/ndt/gfr612] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The urokinase receptor (uPAR) and its soluble form play a key role in the pathogenesis of focal segmental glomerulosclerosis (FSGS). The modification of uPAR pathological actions on podocytes will become an important task for the development of improved nephroprotective therapeutics. Here we show that podocyte uPAR expression can be reduced using amiloride. Amiloride has a significant role in the reduction of podocyte cell motility in vitro and proteinuria in mice. Amiloride inhibited the induction of uPAR protein and PLAUR messenger RNA (encoding uPAR) and with that it reduced uPAR-mediated β3 integrin activation in lipopolysaccharide (LPS)-treated podocytes. Transwell migration assay and wound healing assay showed that directed and random podocyte motility of LPS-treated podocytes were increased and substantially reduced by amiloride. The off-target effect of amiloride was independent of its function as epithelial sodium channel blocker and different from triamterene. Amiloride was also effective in the LPS mouse model of transient proteinuria (LPS mice) and in the 5/6 nephrectomy rat FSGS model (NTX) by significantly inhibiting podocyte uPAR induction, reducing proteinuria. In addition, amiloride attenuated glomerulosclerosis, as determined by glomerulosclerotic index. Thus, our observations show that amiloride inhibits podocyte uPAR induction and reduces proteinuria in NTX rats and LPS mice. Given the pathological relevance of the uPAR-β3 integrin signaling axis in FSGS, amiloride may be utilized in patients with FSGS.
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Affiliation(s)
- Bin Zhang
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
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49
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Abstract
As an integral member of the filtration barrier in the kidney glomerulus, the podocyte is in a unique geographical position: It is exposed to chemical signals from the urinary space (Bowman's capsule), it receives and transmits chemical and mechanical signals to/from the glomerular basement membrane upon which it elaborates, and it receives chemical and mechanical signals from the vascular space with which it also communicates. As with every cell, the ability of the podocyte to receive signals from the surrounding environment and to translate them to the intracellular milieu is dependent largely on molecules residing on the cell membrane. These molecules are the first-line soldiers in the ongoing battle to sense the environment, to respond to friendly signals, and to defend against injurious foes. In this review, we take a membrane biologist's view of the podocyte, examining the many membrane receptors, channels, and other signaling molecules that have been implicated in podocyte biology. Although we attempt to be comprehensive, our goal is not to capture every membrane-mediated pathway but rather to emphasize that this approach may be fruitful in understanding the podocyte and its unique properties.
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Affiliation(s)
- Anna Greka
- Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, USA.
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50
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Shimada M, Ishimoto T, Lee PY, Lanaspa MA, Rivard CJ, Roncal-Jimenez CA, Wymer DT, Yamabe H, Mathieson PW, Saleem MA, Garin EH, Johnson RJ. Toll-like receptor 3 ligands induce CD80 expression in human podocytes via an NF-κB-dependent pathway. Nephrol Dial Transplant 2011; 27:81-9. [PMID: 21617192 DOI: 10.1093/ndt/gfr271] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Recent studies suggest that CD80 (also known as B7.1) is expressed on podocytes in minimal-change disease (MCD) and may have a role in mediating proteinuria. CD80 expression is known to be induced by Toll-like receptor (TLR) ligands in dendritic cells. We therefore evaluated the ability of TLR to induce CD80 in human cultured podocytes. METHODS Conditionally immortalized human podocytes were evaluated for TLR expression. Based on high expression of TLR3, we evaluated the effect of polyinosinic-polycytidylic acid (polyIC), a TLR3 ligand, to induce CD80 expression in vitro. RESULTS TLR1-6 and 9 messenger RNA (mRNA) were expressed in podocytes. Among TLR ligands 1-9, CD80 mRNA expression was significantly induced by polyIC and lipopolysaccharide (TLR4 ligand) with the greatest stimulation by polyIC (6.8 ± 0.7 times at 6 h, P < 0.001 versus control). PolyIC induced increased expression of Cathepsin L, decreased synaptopodin expression and resulted in actin reorganization which suggested a similar injury pattern as observed with lipopolyssaccharide. PolyIC induced type I and type II interferon signaling, nuclear factor kappa B (NF-κB) activation and the induction of CD80 expression. Knockdown of CD80 protected against actin reorganization and reduced synaptopodin expression in response to polyIC. Dexamethasone, a corticosteroid commonly used to treat MCD, also blocked both basal and polyIC-stimulated CD80 expression, as did inhibition of NF-κB. CONCLUSIONS Activation of TLR3 on cultured human podocytes induces CD80 expression and phenotypic change via an NF-κB-dependent mechanism and is partially blocked by dexamethasone. These studies provide a mechanism by which viral infections may cause proteinuria.
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Affiliation(s)
- Michiko Shimada
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, CO, USA.
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