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Sheng A, Liu F, Wang Q, Fu H, Mao J. The roles of TRPC6 in renal tubular disorders: a narrative review. Ren Fail 2024; 46:2376929. [PMID: 39022902 PMCID: PMC11259070 DOI: 10.1080/0886022x.2024.2376929] [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: 01/05/2024] [Accepted: 07/02/2024] [Indexed: 07/20/2024] Open
Abstract
The transient receptor potential canonical 6 (TRPC6) channel, a nonselective cation channel that allows the passage of Ca2+, plays an important role in renal diseases. TRPC6 is activated by Ca2+ influx, oxidative stress, and mechanical stress. Studies have shown that in addition to glomerular diseases, TRPC6 can contribute to renal tubular disorders, such as acute kidney injury, renal interstitial fibrosis, and renal cell carcinoma (RCC). However, the tubule-specific physiological functions of TRPC6 have not yet been elucidated. Its pathophysiological role in ischemia/reperfusion (I/R) injury is debatable. Thus, TRPC6 may have dual roles in I/R injury. TRPC6 induces renal fibrosis and immune cell infiltration in a unilateral ureteral obstruction (UUO) mouse model. Additionally, TRPC6 overexpression may modify G2 phase transition, thus altering the DNA damage checkpoint, which can cause genomic instability and RCC tumorigenesis and can control the proliferation of RCC cells. This review highlights the importance of TRPC6 in various conditions of the renal tubular system. To better understand certain renal disorders and ultimately identify new therapeutic targets to improve patient care, the pathophysiology of TRPC6 must be clarified.
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Affiliation(s)
- Aiqin Sheng
- Department of Nephrology, Children’s Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Fei Liu
- Department of Nephrology, Children’s Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Qianhui Wang
- Department of Nephrology, Children’s Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Haidong Fu
- Department of Nephrology, Children’s Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jianhua Mao
- Department of Nephrology, Children’s Hospital, Zhejiang University School of Medicine, Hangzhou, China
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2
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Bărar AA, Pralea IE, Maslyennikov Y, Munteanu R, Berindan-Neagoe I, Pîrlog R, Rusu I, Nuțu A, Rusu CC, Moldovan DT, Potra AR, Tirinescu D, Ticala M, Elec FI, Iuga CA, Kacso IM. Minimal Change Disease: Pathogenetic Insights from Glomerular Proteomics. Int J Mol Sci 2024; 25:5613. [PMID: 38891801 PMCID: PMC11171934 DOI: 10.3390/ijms25115613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 05/13/2024] [Accepted: 05/15/2024] [Indexed: 06/21/2024] Open
Abstract
The mechanism underlying podocyte dysfunction in minimal change disease (MCD) remains unknown. This study aimed to shed light on the potential pathophysiology of MCD using glomerular proteomic analysis. Shotgun proteomics using label-free quantitative mass spectrometry was performed on formalin-fixed, paraffin-embedded (FFPE) renal biopsies from two groups of samples: control (CTR) and MCD. Glomeruli were excised from FFPE renal biopsies using laser capture microdissection (LCM), and a single-pot solid-phase-enhanced sample preparation (SP3) digestion method was used to improve yield and protein identifications. Principal component analysis (PCA) revealed a distinct separation between the CTR and MCD groups. Forty-eight proteins with different abundance between the two groups (p-value ≤ 0.05 and |FC| ≥ 1.5) were identified. These may represent differences in podocyte structure, as well as changes in endothelial or mesangial cells and extracellular matrix, and some were indeed found in several of these structures. However, most differentially expressed proteins were linked to the podocyte cytoskeleton and its dynamics. Some of these proteins are known to be involved in focal adhesion (NID1 and ITGA3) or slit diaphragm signaling (ANXA2, TJP1 and MYO1C), while others are structural components of the actin and microtubule cytoskeleton of podocytes (ACTR3 and NES). This study suggests the potential of mass spectrometry-based shotgun proteomic analysis with LCM glomeruli to yield valuable insights into the pathogenesis of podocytopathies like MCD. The most significantly dysregulated proteins in MCD could be attributable to cytoskeleton dysfunction or may be a compensatory response to cytoskeleton malfunction caused by various triggers.
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Affiliation(s)
- Andrada Alina Bărar
- Department of Nephrology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (A.A.B.); (Y.M.); (C.C.R.); (D.T.M.); (A.R.P.); (D.T.); (M.T.); (I.M.K.)
| | - Ioana-Ecaterina Pralea
- Department of Proteomics and Metabolomics, Research Center for Advanced Medicine–MedFuture, “Iuliu Hațieganu” University of Medicine and Pharmacy Cluj-Napoca, Louis Pasteur Street 4-6, 400349 Cluj-Napoca, Romania;
| | - Yuriy Maslyennikov
- Department of Nephrology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (A.A.B.); (Y.M.); (C.C.R.); (D.T.M.); (A.R.P.); (D.T.); (M.T.); (I.M.K.)
| | - Raluca Munteanu
- Department of In Vivo Studies, Research Center for Advanced Medicine–MedFuture, “Iuliu Hațieganu” University of Medicine and Pharmacy Cluj-Napoca, Louis Pasteur Street 6, 400349 Cluj-Napoca, Romania;
| | - Ioana Berindan-Neagoe
- Research Center for Functional Genomics, Biomedicine and Translational Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400337 Cluj-Napoca, Romania; (I.B.-N.); (R.P.); (A.N.)
| | - Radu Pîrlog
- Research Center for Functional Genomics, Biomedicine and Translational Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400337 Cluj-Napoca, Romania; (I.B.-N.); (R.P.); (A.N.)
| | - Ioana Rusu
- Department of Pathology, Regional Institute of Gastroenterology and Hepatology, 400394 Cluj-Napoca, Romania;
| | - Andreea Nuțu
- Research Center for Functional Genomics, Biomedicine and Translational Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400337 Cluj-Napoca, Romania; (I.B.-N.); (R.P.); (A.N.)
| | - Crina Claudia Rusu
- Department of Nephrology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (A.A.B.); (Y.M.); (C.C.R.); (D.T.M.); (A.R.P.); (D.T.); (M.T.); (I.M.K.)
| | - Diana Tania Moldovan
- Department of Nephrology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (A.A.B.); (Y.M.); (C.C.R.); (D.T.M.); (A.R.P.); (D.T.); (M.T.); (I.M.K.)
| | - Alina Ramona Potra
- Department of Nephrology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (A.A.B.); (Y.M.); (C.C.R.); (D.T.M.); (A.R.P.); (D.T.); (M.T.); (I.M.K.)
| | - Dacian Tirinescu
- Department of Nephrology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (A.A.B.); (Y.M.); (C.C.R.); (D.T.M.); (A.R.P.); (D.T.); (M.T.); (I.M.K.)
| | - Maria Ticala
- Department of Nephrology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (A.A.B.); (Y.M.); (C.C.R.); (D.T.M.); (A.R.P.); (D.T.); (M.T.); (I.M.K.)
| | - Florin Ioan Elec
- Department of Urology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania;
| | - Cristina Adela Iuga
- Department of Proteomics and Metabolomics, Research Center for Advanced Medicine–MedFuture, “Iuliu Hațieganu” University of Medicine and Pharmacy Cluj-Napoca, Louis Pasteur Street 4-6, 400349 Cluj-Napoca, Romania;
- Department of Pharmaceutical Analysis, Faculty of Pharmacy, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400349 Cluj-Napoca, Romania
| | - Ina Maria Kacso
- Department of Nephrology, Faculty of Medicine, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (A.A.B.); (Y.M.); (C.C.R.); (D.T.M.); (A.R.P.); (D.T.); (M.T.); (I.M.K.)
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Pukajło-Marczyk A, Zwolińska D. The Role of TNF-α in the Pathogenesis of Idiopathic Nephrotic Syndrome and Its Usefulness as a Marker of the Disease Course. J Clin Med 2024; 13:1888. [PMID: 38610653 PMCID: PMC11012282 DOI: 10.3390/jcm13071888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Revised: 03/03/2024] [Accepted: 03/21/2024] [Indexed: 04/14/2024] Open
Abstract
Background: The pathogenesis of idiopathic nephrotic syndrome (INS) has not been fully explained. Among the likely factors, tumor necrosis factor - alpha (TNF-α) is considered. We aimed to evaluate the TNF-α (sTNF-α, uTNF-α) levels in the serum and urine of INS children, with the aim of determining its association with proteinuria, and of determining its usefulness as a marker of the disease severity. Methods: Fifty-one examined patients were divided into subgroups depending on the number of relapses as follows: group IA-first episode; group IB-more than two relapses, and according to treatment modality; group IIA-glucocorticosteroids (GS) alone; and group IIB-GS with immunosuppressants. Healthy age-matched children served as the control group. Results: sTNF-α and uTNF-α levels were significantly increased in active phases in the whole INS group compared to the control group. They decreased in remission, but remained significantly higher when compared to the control group. During remission in the IB group, sTNF-α levels were significantly higher than in IA, whereas, in the relapse phase, these values were similar. In the IA group, a positive correlation between proteinuria and sTNF-α was demonstrated. Conclusions: Our findings suggest that TNF-α plays a role in the development of INS, and may be used as a prognostic marker, as well as an indicator for the continuation of therapy. Additional research is required to verify this statement.
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Affiliation(s)
- Agnieszka Pukajło-Marczyk
- Department of Pediatric Nephrology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw, Poland;
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Cara-Fuentes G, Verma R, Venkatareddy M, Bauer C, Piani F, Aksoy ST, Vazzalwar N, Garcia GE, Banks M, Ordoñez FA, de Lucas-Collantes C, Bjornstad P, González Rodríguez JD, Johnson RJ, Garg P. β1-Integrin blockade prevents podocyte injury in experimental models of minimal change disease. Nefrologia 2024; 44:90-99. [PMID: 37150673 DOI: 10.1016/j.nefroe.2023.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 11/10/2022] [Indexed: 05/09/2023] Open
Abstract
INTRODUCTION Activation of the focal adhesion kinase (FAK) in podocytes is involved in the pathogenesis of minimal change disease (MCD), but the pathway leading to its activation in this disease is unknown. Here, we tested whether podocyte β1 integrin is the upstream modulator of FAK activation and podocyte injury in experimental models of MCD-like injury. METHODS We used lipopolysaccharide (LPS) and MCD sera to induce MCD-like changes in vivo and in cultured human podocytes, respectively. We performed functional studies using specific β1 integrin inhibitors in vivo and in vitro, and integrated histological analysis, western blotting, and immunofluorescence to assess for morphological and molecular changes in podocytes. By ELISA, we measured serum LPS levels in 35 children with MCD or presumed MCD (idiopathic nephrotic syndrome [INS]) and in 18 healthy controls. RESULTS LPS-injected mice showed morphological (foot process effacement, and normal appearing glomeruli on light microscopy) and molecular features (synaptopodin loss, nephrin mislocalization, FAK phosphorylation) characteristic of human MCD. Administration of a β1 integrin inhibitor to mice abrogated FAK phosphorylation, and ameliorated proteinuria and podocyte injury following LPS. Children with MCD/INS in relapse had higher serum LPS levels than controls. In cultured human podocytes, β1 integrin blockade prevented cytoskeletal rearrangements following exposure to MCD sera in relapse. CONCLUSIONS Podocyte β1 integrin activation is an upstream mediator of FAK phosphorylation and podocyte injury in models of MCD-like injury.
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Salfi G, Casiraghi F, Remuzzi G. Current understanding of the molecular mechanisms of circulating permeability factor in focal segmental glomerulosclerosis. Front Immunol 2023; 14:1247606. [PMID: 37795085 PMCID: PMC10546017 DOI: 10.3389/fimmu.2023.1247606] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 09/05/2023] [Indexed: 10/06/2023] Open
Abstract
The pathogenetic mechanisms underlying the onset and the post-transplant recurrence of primary focal segmental glomerulosclerosis (FSGS) are complex and remain yet to be fully elucidated. However, a growing body of evidence emphasizes the pivotal role of the immune system in both initiating and perpetuating the disease. Extensive investigations, encompassing both experimental models and patient studies, have implicated T cells, B cells, and complement as crucial actors in the pathogenesis of primary FSGS, with various molecules being proposed as potential "circulating factors" contributing to the disease and its recurrence post kidney-transplantation. In this review, we critically assessed the existing literature to identify essential pathways for a comprehensive characterization of the pathogenesis of FSGS. Recent discoveries have shed further light on the intricate interplay between these mechanisms. We present an overview of the current understanding of the engagement of distinct molecules and immune cells in FSGS pathogenesis while highlighting critical knowledge gaps that require attention. A thorough characterization of these intricate immune mechanisms holds the potential to identify noninvasive biomarkers that can accurately identify patients at high risk of post-transplant recurrence. Such knowledge can pave the way for the development of targeted and personalized therapeutic approaches in the management of FSGS.
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Affiliation(s)
| | - Federica Casiraghi
- Istituto di Ricerche Farmacologiche Mario Negri Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Bergamo, Italy
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Vivarelli M, Gibson K, Sinha A, Boyer O. Childhood nephrotic syndrome. Lancet 2023; 402:809-824. [PMID: 37659779 DOI: 10.1016/s0140-6736(23)01051-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 05/04/2023] [Accepted: 05/19/2023] [Indexed: 09/04/2023]
Abstract
Idiopathic nephrotic syndrome is the most common glomerular disease in children. Corticosteroids are the cornerstone of its treatment, and steroid response is the main prognostic factor. Most children respond to a cycle of oral steroids, and are defined as having steroid-sensitive nephrotic syndrome. Among the children who do not respond, defined as having steroid-resistant nephrotic syndrome, most respond to second-line immunosuppression, mainly with calcineurin inhibitors, and children in whom a response is not observed are described as multidrug resistant. The pathophysiology of nephrotic syndrome remains elusive. In cases of immune-mediated origin, dysregulation of immune cells and production of circulating factors that damage the glomerular filtration barrier have been described. Conversely, up to a third of cases of steroid-resistant nephrotic syndrome have a monogenic origin. Multidrug resistant nephrotic syndrome often leads to kidney failure and can cause relapse after kidney transplant. Although steroid-sensitive nephrotic syndrome does not affect renal function, most children with steroid-sensitive nephrotic syndrome have a relapsing course that requires repeated steroid cycles with significant side-effects. To minimise morbidity, some patients require steroid-sparing immunosuppressive agents, including levamisole, mycophenolate mofetil, calcineurin inhibitors, anti-CD20 monoclonal antibodies, and cyclophosphamide. Close monitoring and preventive measures are warranted at onset and during relapse to prevent acute complications (eg, hypovolaemia, acute kidney injury, infections, and thrombosis), whereas long-term management requires minimising treatment-related side-effects. A subset of patients have active disease into adulthood.
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Affiliation(s)
- Marina Vivarelli
- Division of Nephrology, Laboratory of Nephrology, Bambino Gesù Children's Hospital IRCCS, Rome, Italy.
| | - Keisha Gibson
- Division of Nephrology and Hypertension, University of North Carolina Kidney Center, University of North Carolina at Chapel Hill, NC, USA
| | - Aditi Sinha
- Division of Nephrology, Indian Council of Medical Research Center for Advanced Research in Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Olivia Boyer
- Néphrologie Pédiatrique, Centre de Référence Maladies Rénales Héréditaires de l'Enfant et de l'Adulte, Hôpital Necker - Enfants Malades, Assistance Publique Hôpitaux de Paris, Inserm U1163, Institut Imagine, Université Paris Cité, Paris, France
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Ye Q, Wang DJ, Lan B, Mao JH. T-cell and B-cell repertoire diversity are selectively skewed in children with idiopathic nephrotic syndrome revealed by high-throughput sequencing. World J Pediatr 2023; 19:273-282. [PMID: 36449136 DOI: 10.1007/s12519-022-00640-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 10/12/2022] [Indexed: 12/05/2022]
Abstract
BACKGROUND Clinical studies suggest that the dysfunction of T cells and B cells may play an essential role in the pathogenesis of idiopathic nephrotic syndrome (INS), but laboratory evidence is lacking. Therefore, this study explored T-cell receptor (TCR) and B-cell receptor (BCR) profiling in children with idiopathic nephrotic syndrome. METHODS High-throughput sequencing technology was used to profile the TCR and BCR repertoires in children with INS. Peripheral blood was collected from ten INS patients, including five vinculin autoantibody-positive patients and five vinculin autoantibody-negative patients, before and after treatment. TCR and BCR libraries were constructed by 5'-RACE and sequenced by a DNBSEQ-T7 sequencer, and sequence analyses were performed using ReSeqTools, FastP, MiXCR, and VDJtools. RESULTS The TRA (T-cell receptor α), TRG (T-cell receptor γ), and IGH (immunoglobulin heavy chain) repertoires of the INS group were occupied by highly abundant clonotypes, whereas small clonotypes occupied the healthy group, especially TRA. A significant increase in the Shannon-Weaver index was observed for the TRA and TRG repertoires after treatment in vinculin autoantibody-negative patients, but a significant increase in the IGH repertoire after treatment was observed in vinculin autoantibody-positive patients. The frequency of some V-J pairs was significantly enriched in steroid-sensitive nephrotic syndrome patients. The usage frequency of the V and J genes was skewed in patients, which seemed not related to immunosuppressive therapy. However, after effective treatment, dynamic changes in the size of the individual clonotype were observed. CONCLUSION T-cell and B-cell immunity contribute to the pathogenesis of different INSs. Video: (MP4 99,786 KB).
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Affiliation(s)
- Qing Ye
- Department of Clinical Laboratory, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Children's Regional Medical Center, Hangzhou, 310052, China
| | - Dong-Jie Wang
- Department of Nephrology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Children's Regional Medical Center, Hangzhou, 310052, China
| | - Bing Lan
- Department of Nephrology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Children's Regional Medical Center, Hangzhou, 310052, China
| | - Jian-Hua Mao
- Department of Nephrology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Children's Regional Medical Center, Hangzhou, 310052, China.
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Therapeutic trials in difficult to treat steroid sensitive nephrotic syndrome: challenges and future directions. Pediatr Nephrol 2023; 38:17-34. [PMID: 35482099 PMCID: PMC9048617 DOI: 10.1007/s00467-022-05520-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 02/07/2022] [Accepted: 02/24/2022] [Indexed: 01/10/2023]
Abstract
Steroid sensitive nephrotic syndrome is a common condition in pediatric nephrology, and most children have excellent outcomes. Yet, 50% of children will require steroid-sparing agents due to frequently relapsing disease and may suffer consequences from steroid dependence or use of steroid-sparing agents. Several steroid-sparing therapeutic agents are available with few high quality randomized controlled trials to compare efficacy leading to reliance on observational data for clinical guidance. Reported trials focus on short-term outcomes such as time to first relapse, relapse rates up to 1-2 years of follow-up, and few have studied long-term remission. Trial designs often do not consider inter-individual variability, and differing response to treatments may occur due to heterogeneity in pathogenic mechanisms, and genetic and environmental influences. Strategies are proposed to improve the quantity and quality of trials in steroid sensitive nephrotic syndrome with integration of biomarkers, novel trial designs, and standardized outcomes, especially for long-term remission. Collaborative efforts among international trial networks will help move us toward a shared goal of finding a cure for children with nephrotic syndrome.
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Hada I, Shimizu A, Takematsu H, Nishibori Y, Kimura T, Fukutomi T, Kudo A, Ito-Nitta N, Kiuchi Z, Patrakka J, Mikami N, Leclerc S, Akimoto Y, Hirayama Y, Mori S, Takano T, Yan K. A Novel Mouse Model of Idiopathic Nephrotic Syndrome Induced by Immunization with the Podocyte Protein Crb2. J Am Soc Nephrol 2022; 33:2008-2025. [PMID: 35985815 PMCID: PMC9678040 DOI: 10.1681/asn.2022010070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 07/25/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The cause of podocyte injury in idiopathic nephrotic syndrome (INS) remains unknown. Although recent evidence points to the role of B cells and autoimmunity, the lack of animal models mediated by autoimmunity limits further research. We aimed to establish a mouse model mimicking human INS by immunizing mice with Crb2, a transmembrane protein expressed at the podocyte foot process. METHODS C3H/HeN mice were immunized with the recombinant extracellular domain of mouse Crb2. Serum anti-Crb2 antibody, urine protein-to-creatinine ratio, and kidney histology were studied. For signaling studies, a Crb2-expressing mouse podocyte line was incubated with anti-Crb2 antibody. RESULTS Serum anti-Crb2 autoantibodies and significant proteinuria were detected 4 weeks after the first immunization. The proteinuria reached nephrotic range at 9-13 weeks and persisted up to 29 weeks. Initial kidney histology resembled minimal change disease in humans, and immunofluorescence staining showed delicate punctate IgG staining in the glomerulus, which colocalized with Crb2 at the podocyte foot process. A subset of mice developed features resembling FSGS after 18 weeks. In glomeruli of immunized mice and in Crb2-expressing podocytes incubated with anti-Crb2 antibody, phosphorylation of ezrin, which connects Crb2 to the cytoskeleton, increased, accompanied by altered Crb2 localization and actin distribution. CONCLUSION The results highlight the causative role of anti-Crb2 autoantibody in podocyte injury in mice. Crb2 immunization could be a useful model to study the immunologic pathogenesis of human INS, and may support the role of autoimmunity against podocyte proteins in INS.
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Affiliation(s)
- Ichiro Hada
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - Akira Shimizu
- Department of Analytic Human Pathology, Nippon Medical School, Tokyo, Japan
| | - Hiromu Takematsu
- Department of Molecular Cell Biology, Faculty of Medical Technology, Graduate School of Health Sciences, Fujita Health University, Toyoake, Japan
| | - Yukino Nishibori
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - Toru Kimura
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Tokyo, Japan
| | - Toshiyuki Fukutomi
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Tokyo, Japan
| | - Akihiko Kudo
- Department of Microscopic Anatomy, Kyorin University School of Medicine, Tokyo, Japan
| | - Noriko Ito-Nitta
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - Zentaro Kiuchi
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - Jaakko Patrakka
- KI/AZ Integrated Cardio Metabolic Center, Department of Laboratory Medicine, Karolinska Institutet at Karolinska University Hospital, Stockholm, Sweden
| | - Naoaki Mikami
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
| | - Simon Leclerc
- Department of Medicine, Division of Nephrology, Research Institute of the McGill University Health Centre, Montreal, Canada
| | - Yoshihiro Akimoto
- Department of Microscopic Anatomy, Kyorin University School of Medicine, Tokyo, Japan
| | - Yoshiaki Hirayama
- Vaccine & Reagent, R&D Department, Denka Co., Ltd, Gosen-City, Japan
| | - Satoka Mori
- Denka Innovation Center, Denka Co., Ltd, Machida, Japan
| | - Tomoko Takano
- Department of Medicine, Division of Nephrology, Research Institute of the McGill University Health Centre, Montreal, Canada
| | - Kunimasa Yan
- Department of Pediatrics, Kyorin University School of Medicine, Tokyo, Japan
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Liu J, Guan F. B cell phenotype, activity, and function in idiopathic nephrotic syndrome. Pediatr Res 2022:10.1038/s41390-022-02336-w. [PMID: 36316536 DOI: 10.1038/s41390-022-02336-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 09/14/2022] [Accepted: 09/20/2022] [Indexed: 11/05/2022]
Abstract
Idiopathic nephrotic syndrome (INS) is the most frequent glomerular disease in childhood. However, its underlying etiology mechanism lacks thorough understanding. Previous studies have described INS as a T cell functional disorder resulting in increased plasma lymphocyte-derived permeability factors. In children with frequent relapses of nephrotic syndrome, the mechanism underlying the therapeutic efficacy of CD20 monoclonal antibodies in depleting B cells may provide additional evidence in exploring the critical role of B lymphocytes in INS pathogenesis. Previous studies have proposed that RTX bound to CD20 through antibody-dependent and complement-dependent cytotoxicity and led to lytic clearance of B cells. Additionally, RTX exerted an effect by blocking the interaction between B and T cells or regulating homeostasis and functions of T cell subsets. Recent studies on the development, differentiation, and activation of B-lymphocytes in glomerular diseases have suggested that the B-lymphocytes participate in the INS pathogenesis through interaction with T cells, secretion of antibodies, or production of cytokines. In this study, we aimed to provide a detailed description of the current knowledge on the development, differentiation, activity, functions, and related regulating factors of B cells involved in INS. Thus, further understanding of the immunopathogenesis of INS may offer some opportunities in precisely targeting B cells during therapeutic interventions. IMPACT: The topic "B cells play a role in glomerular disease" is a novel point, which is not completely described previously. We described interactions between T and B cells and immunoglobulin, IgG, IgM, IgE, etc. as well in glomerular disease. The research of regulatory factors associated with B cell's function, like BAFF, is a hot topic in other diseases; however, it is rare in glomerular disease.
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Affiliation(s)
- Junhan Liu
- Department of Pediatrics, Affiliated Hospital of Xuzhou Medical University, 221002, Xuzhou, Jiangsu, China
| | - Fengjun Guan
- Department of Pediatrics, Affiliated Hospital of Xuzhou Medical University, 221002, Xuzhou, Jiangsu, China.
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Cara-Fuentes G, Andres-Hernando A, Bauer C, Banks M, Garcia GE, Cicerchi C, Kuwabara M, Shimada M, Johnson RJ, Lanaspa MA. Pulmonary surfactants and the respiratory-renal connection in steroid-sensitive nephrotic syndrome of childhood. iScience 2022; 25:104694. [PMID: 35847557 PMCID: PMC9284382 DOI: 10.1016/j.isci.2022.104694] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 05/23/2022] [Accepted: 06/24/2022] [Indexed: 01/21/2023] Open
Abstract
Steroid-sensitive nephrotic syndrome (SSNS) in childhood is usually due to minimal change disease (MCD). Unlike many glomerular conditions, SSNS/MCD is commonly precipitated by respiratory infections. Of interest, pulmonary inflammation releases surfactants in circulation which are soluble agonists of SIRPα, a podocyte receptor that regulates integrin signaling. Here, we characterized this pulmonary-renal connection in MCD and performed studies to determine its importance. Children with SSNS/MCD in relapse but not remission had elevated plasma surfactants and urinary SIRPα. Sera from relapsing subjects triggered podocyte SIRPα signaling via tyrosine phosphatase SHP-2 and nephrin dephosphorylation, a marker of podocyte activation. Further, addition of surfactants to MCD sera from patients in remission replicated these findings. Similarly, nasal instillation of toll-like receptor 3 and 4 agonists in mice resulted in elevated serum surfactants and their binding to glomeruli triggering proteinuria. Together, our data document a critical pulmonary-podocyte signaling pathway involving surfactants and SIRPα signaling in SSNS/MCD.
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Affiliation(s)
| | - Ana Andres-Hernando
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, CO, USA,Division of Nephrology and Hypertension, Oregon Health & Science University, Portland, OR, USA
| | - Colin Bauer
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, CO, USA
| | - Mindy Banks
- Rocky Mountain Pediatric Kidney Center, Denver, CO, USA
| | - Gabriela E. Garcia
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, CO, USA
| | - Christina Cicerchi
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, CO, USA
| | - Masanari Kuwabara
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, CO, USA
| | - Michiko Shimada
- Department of Cardiology and Nephrology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Richard J. Johnson
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, CO, USA
| | - Miguel A. Lanaspa
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, CO, USA,Division of Nephrology and Hypertension, Oregon Health & Science University, Portland, OR, USA,Corresponding author
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12
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Sun IO, Bae YU, Lee H, Kim H, Jeon JS, Noh H, Choi JS, Doh KO, Kwon SH. Circulating miRNAs in extracellular vesicles related to treatment response in patients with idiopathic membranous nephropathy. J Transl Med 2022; 20:224. [PMID: 35568952 PMCID: PMC9107687 DOI: 10.1186/s12967-022-03430-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 05/05/2022] [Indexed: 12/29/2022] Open
Abstract
Background Extracellular vesicle (EV)-microRNAs (miRNAs) are potential biomarkers for various renal diseases. This study attempted to identify the circulating EV-miRNA signature not only for discriminating idiopathic membranous nephropathy (IMN) from idiopathic nephrotic syndrome (INS), but also to predict the treatment response of patients with IMN. Methods We prospectively enrolled 60 participants, including those with IMN (n = 19) and INS (n = 21) and healthy volunteers (HVs; n = 20) in this study. Using RNA sequencing, we assessed the serum EV-miRNA profiles of all participants. To identify the EV-miRNAs predictive of treatment response in IMN, we also analyzed EV-miRNAs among patients with IMN with and without clinical remission. Results The expression levels of 3 miRNAs differed between IMN patients, INS patients and HVs. In addition, compared to HVs, RNA sequencing revealed differential expression of 77 and 44 EV-miRNAs in patients with IMN without and with remission, respectively. We also identified statistically significant (|fold change ≥ 2, p < 0.05) differences in the expression levels of 23 miRNAs in IMN without remission. Biological pathway analysis of miRNAs in IMN without remission indicated that they are likely involved in various pathways, including renal fibrosis. Conclusion Our study identified EV-miRNAs associated with IMN as well as those associations with therapeutic response. Therefore, these circulating EV-miRNAs may be used as potential markers for the diagnosis and prediction of treatment response in patients with IMN. Supplementary Information The online version contains supplementary material available at 10.1186/s12967-022-03430-7.
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Affiliation(s)
- In O Sun
- Division of Nephrology, Department of Internal Medicine, Presbyterian Medical Center, Jeonju, Republic of Korea
| | - Yun-Ui Bae
- Department of Internal Medicine, Keimyung University Dongsan Hospital, Keimyung University School of Medicine, Daegu, Republic of Korea
| | - Haekyung Lee
- Division of Nephrology, Soonchunhyang University Seoul Hospital, 59 Daesagwan-ro, Youngsan-gu, Seoul, 04401, Republic of Korea
| | - Hyoungnae Kim
- Division of Nephrology, Soonchunhyang University Seoul Hospital, 59 Daesagwan-ro, Youngsan-gu, Seoul, 04401, Republic of Korea
| | - Jin Seok Jeon
- Division of Nephrology, Soonchunhyang University Seoul Hospital, 59 Daesagwan-ro, Youngsan-gu, Seoul, 04401, Republic of Korea
| | - Hyunjin Noh
- Division of Nephrology, Soonchunhyang University Seoul Hospital, 59 Daesagwan-ro, Youngsan-gu, Seoul, 04401, Republic of Korea
| | - Jong-Soo Choi
- Department of Physiology, College of Medicine, Yeungnam University, Daegu, 42415, Republic of Korea
| | - Kyung-Oh Doh
- Department of Physiology, College of Medicine, Yeungnam University, Daegu, 42415, Republic of Korea.
| | - Soon Hyo Kwon
- Division of Nephrology, Soonchunhyang University Seoul Hospital, 59 Daesagwan-ro, Youngsan-gu, Seoul, 04401, Republic of Korea.
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13
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Association between gaseous air pollutants and idiopathic nephrotic syndrome in children: a 12-year population-based cohort study. Ital J Pediatr 2022; 48:70. [PMID: 35549987 PMCID: PMC9097133 DOI: 10.1186/s13052-022-01269-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 05/03/2022] [Indexed: 12/02/2022] Open
Abstract
Background To date, there is insufficient knowledge about the association of air pollution and childhood nephrotic syndrome in the real world. This study aimed to evaluate the effects of the three common gaseous air pollutants, including sulfur dioxide, total hydrocarbon, and methane, on the risk of idiopathic nephrotic syndrome (INS) in children. Methods We collected data from the Taiwan National Health Insurance Research Database and Taiwan Air Quality-Monitoring Database. Children younger than 18 years old, identified from January 1, 2000, were followed up until the first diagnosis of INS was established or until December 31, 2012. We measured the incidence rates and hazard ratios for INS stratified based on the quartiles (Q1–Q4) of air pollutant concentration. Multivariate Cox proportional hazards models were also applied by adjusting age, sex, monthly income, and urbanization. Results Compared with participants exposed to Q1 concentrations, the adjusted hazard ratios (aHRs) for INS increased progressively along the four quartiles of sulfur dioxide, total hydrocarbon, and methane, from 1 (Q1) to 1.78 (Q4), 1 (Q1) to 3.49 (Q4), 1 (Q1) to 7.83 (Q4), respectively. Conclusions Our study revealed that children with exposure to higher concentrations of sulfur dioxide, total hydrocarbon, and methane was associated with an increased risk of INS. Supplementary Information The online version contains supplementary material available at 10.1186/s13052-022-01269-8.
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Second and Third Generational Advances in Therapies of the Immune-Mediated Kidney Diseases in Children and Adolescents. CHILDREN 2022; 9:children9040536. [PMID: 35455580 PMCID: PMC9030090 DOI: 10.3390/children9040536] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/06/2022] [Accepted: 04/08/2022] [Indexed: 11/17/2022]
Abstract
Therapy of immune-mediated kidney diseases has evolved during recent decades from the non-specific use of corticosteroids and antiproliferative agents (like cyclophosphamide or azathioprine), towards the use of more specific drugs with measurable pharmacokinetics, like calcineurin inhibitors (cyclosporine A and tacrolimus) and mycophenolate mofetil, to the treatment with biologic drugs targeting detailed specific receptors, like rituximab, eculizumab or abatacept. Moreover, the data coming from a molecular science revealed that several drugs, which have been previously used exclusively to modify the upregulated adaptive immune system, may also exert a local effect on the kidney microstructure and ameliorate the functional instability of podocytes, reducing the leak of protein into the urinary space. The innate immune system also became a target of new therapies, as its specific role in different kidney diseases has been de novo defined. Current therapy of several immune kidney diseases may now be personalized, based on the detailed diagnostic procedures, including molecular tests. However, in most cases there is still a space for standard therapies based on variable protocols including usage of steroids with the steroid-sparing agents. They are used as a first-line treatment, while modern biologic agents are selected as further steps in cases of lack of the efficacy or toxicity of the basic therapies. In several clinical settings, the biologic drugs are effective as the add-on therapy.
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15
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Colucci M, Oniszczuk J, Vivarelli M, Audard V. B-Cell Dysregulation in Idiopathic Nephrotic Syndrome: What We Know and What We Need to Discover. Front Immunol 2022; 13:823204. [PMID: 35140723 PMCID: PMC8819007 DOI: 10.3389/fimmu.2022.823204] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 01/04/2022] [Indexed: 11/18/2022] Open
Abstract
The therapeutic efficacy of B-cell depletion by anti-CD20 treatment in pediatric and, more recently, in adult idiopathic nephrotic syndrome patients suggests a key role of B cells in the pathogenesis of the disease. However, their exact role is still unclear. B cells are able to secrete a large variety of antibodies that can protect against infections. However, B-cell dysregulation is well-established in a variety of autoimmune diseases. In parallel with their ability to produce antibodies, pathogenic B cells display altered effector functions by expressing activating surface molecules, which can strongly modify the immune homeostasis, or by producing specific cytokines, which can directly affect either podocyte structure and functions or modulate T-cell homeostasis. Herein, we report the most relevant clinical and experimental evidences of a pathogenic role of B cells in idiopathic nephrotic syndrome. We further highlight similarities and differences between children and adults affected by non-genetic forms of the disease and discuss what needs to be investigated in order to define the exact mechanisms underlying the pathogenic role of B cells and to identify more tailored therapeutic approaches.
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Affiliation(s)
- Manuela Colucci
- Renal Diseases Research Unit, Genetics and Rare Diseases Research Area, Bambino Gesù Children’s Hospital, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
- *Correspondence: Manuela Colucci,
| | - Julie Oniszczuk
- Assistance Publique des Hôpitaux de Paris, Hôpitaux Universitaires Henri-Mondor, Service de Néphrologie et Transplantation, Centre de Référence Maladie Rare “Syndrome Néphrotique Idiopathique”, Fédération Hospitalo-Universitaire, Innovative Therapy for Immune Disorders, Créteil, France
- Univ Paris Est Créteil, Institut National de la Santé et de la Recherche Médicale (INSERM) U955, Institut Mondor de Recherche Biomédicale (IMRB), Créteil, France
| | - Marina Vivarelli
- Division of Nephrology, Department of Pediatric Subspecialties, Bambino Gesù Children’s Hospital, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
| | - Vincent Audard
- Assistance Publique des Hôpitaux de Paris, Hôpitaux Universitaires Henri-Mondor, Service de Néphrologie et Transplantation, Centre de Référence Maladie Rare “Syndrome Néphrotique Idiopathique”, Fédération Hospitalo-Universitaire, Innovative Therapy for Immune Disorders, Créteil, France
- Univ Paris Est Créteil, Institut National de la Santé et de la Recherche Médicale (INSERM) U955, Institut Mondor de Recherche Biomédicale (IMRB), Créteil, France
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16
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Purohit S, Piani F, Ordoñez FA, de Lucas-Collantes C, Bauer C, Cara-Fuentes G. Molecular Mechanisms of Proteinuria in Minimal Change Disease. Front Med (Lausanne) 2022; 8:761600. [PMID: 35004732 PMCID: PMC8733331 DOI: 10.3389/fmed.2021.761600] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 10/15/2021] [Indexed: 11/13/2022] Open
Abstract
Minimal change disease (MCD) is the most common type of idiopathic nephrotic syndrome in childhood and represents about 15% cases in adults. It is characterized by massive proteinuria, edema, hypoalbuminemia, and podocyte foot process effacement on electron microscopy. Clinical and experimental studies have shown an association between MCD and immune dysregulation. Given the lack of inflammatory changes or immunocomplex deposits in the kidney tissue, MCD has been traditionally thought to be mediated by an unknown circulating factor(s), probably released by T cells that directly target podocytes leading to podocyte ultrastructural changes and proteinuria. Not surprisingly, research efforts have focused on the role of T cells and podocytes in the disease process. Nevertheless, the pathogenesis of the disease remains a mystery. More recently, B cells have been postulated as an important player in the disease either by activating T cells or by releasing circulating autoantibodies against podocyte targets. There are also few reports of endothelial injury in MCD, but whether glomerular endothelial cells play a role in the disease remains unexplored. Genome-wide association studies are providing insights into the genetic susceptibility to develop the disease and found a link between MCD and certain human haplotype antigen variants. Altogether, these findings emphasize the complex interplay between the immune system, glomerular cells, and the genome, raising the possibility of distinct underlying triggers and/or mechanisms of proteinuria among patients with MCD. The heterogeneity of the disease and the lack of good animal models of MCD remain major obstacles in the understanding of MCD. In this study, we will review the most relevant candidate mediators and mechanisms of proteinuria involved in MCD and the current models of MCD-like injury.
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Affiliation(s)
- Shrey Purohit
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.,Department of Pediatrics, Section of Pediatric Nephrology, Children's Hospital Colorado, Aurora, CO, United States
| | - Federica Piani
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.,Department of Medicine and Surgery Sciences, Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Flor A Ordoñez
- Division of Pediatric Nephrology, Hospital Universitario Central de Asturias, Oviedo, Spain
| | | | - Colin Bauer
- Department of Pediatrics, Section of Pediatric Nephrology, Children's Hospital Colorado, Aurora, CO, United States
| | - Gabriel Cara-Fuentes
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.,Department of Pediatrics, Section of Pediatric Nephrology, Children's Hospital Colorado, Aurora, CO, United States
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17
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da Silva Filha R, Burini K, Pires LG, Brant Pinheiro SV, Simões E Silva AC. Idiopathic Nephrotic Syndrome in Pediatrics: An Up-to-date. Curr Pediatr Rev 2022; 18:251-264. [PMID: 35289253 DOI: 10.2174/1573396318666220314142713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/31/2021] [Accepted: 12/12/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Idiopathic or Primary Nephrotic Syndrome (INS) is a common glomerular disease in pediatric population, characterized by proteinuria, edema and hypoalbuminemia with variable findings in renal histopathology. OBJECTIVE This review aims to summarize current data on the etiopathogenesis diagnosis, protocols of treatment and potential therapeutic advances in INS. METHODS This narrative review searched for articles on histopathology, physiopathology, genetic causes, diagnosis and treatment of INS in pediatric patients. The databases evaluated were PubMed and Scopus. RESULTS INS is caused by an alteration in the permeability of the glomerular filtration barrier with unknown etiology. There are several gaps in the etiopathogenesis, response to treatment and clinical course of INS that justify further investigation. Novel advances include the recent understanding of the role of podocytes in INS and the identification of genes associated with the disease. The role of immune system cells and molecules has also been investigated. The diagnosis relies on clinical findings, laboratory exams and renal histology for selected cases. The treatment is primarily based on steroids administration. In case of failure, other medications should be tried. Recent studies have also searched for novel biomarkers for diagnosis and alternative therapeutic approaches. CONCLUSION The therapeutic response to corticosteroids still remains the main predictive factor for the prognosis of the disease. Genetic and pharmacogenomics tools may allow the identification of cases not responsive to immunosuppressive medications.
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Affiliation(s)
- Roberta da Silva Filha
- Faculty of Medicine, Interdisciplinary Laboratory of Medical Investigation, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Kassia Burini
- Faculty of Medicine, Interdisciplinary Laboratory of Medical Investigation, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Laura Gregório Pires
- Faculty of Medicine, Interdisciplinary Laboratory of Medical Investigation, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | | | - Ana Cristina Simões E Silva
- Faculty of Medicine, Interdisciplinary Laboratory of Medical Investigation, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil.,Department of Pediatrics, Unit of Pediatric Nephrology, Faculty of Medicine, UFMG, Belo Horizonte, MG, Brazil
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18
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Horinouchi T, Nozu K, Iijima K. An updated view of the pathogenesis of steroid-sensitive nephrotic syndrome. Pediatr Nephrol 2022; 37:1957-1965. [PMID: 35006356 PMCID: PMC9307535 DOI: 10.1007/s00467-021-05401-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 11/01/2021] [Accepted: 11/24/2021] [Indexed: 11/28/2022]
Abstract
Idiopathic nephrotic syndrome is the most common childhood glomerular disease. Most forms of this syndrome respond to corticosteroids at standard doses and are, therefore, defined as steroid-sensitive nephrotic syndrome (SSNS). Immunological mechanisms and subsequent podocyte disorders play a pivotal role in SSNS and have been studied for years; however, the precise pathogenesis remains unclear. With recent advances in genetic techniques, an exhaustive hypothesis-free approach called a genome-wide association study (GWAS) has been conducted in various populations. GWASs in pediatric SSNS peaked in the human leukocyte antigen class II region in various populations. Additionally, an association of immune-related CALHM6/FAM26F, PARM1, BTNL2, and TNFSF15 genes, as well as NPHS1, which encodes nephrin expressed in podocytes, has been identified as a locus that achieves genome-wide significance in pediatric SSNS. However, the specific mechanism of SSNS development requires elucidation. This review describes an updated view of SSNS pathogenesis from immunological and genetic aspects, including interactions with infections or allergies, production of circulating factors, and an autoantibody hypothesis.
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Affiliation(s)
- Tomoko Horinouchi
- grid.31432.370000 0001 1092 3077Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kandai Nozu
- grid.31432.370000 0001 1092 3077Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kazumoto Iijima
- Hyogo Prefectural Kobe Children's Hospital, Kobe, Japan. .,Department of Advanced Pediatric Medicine, Kobe University Graduate School of Medicine, Minatojimaminami-machi 1-6-7, Chuo-ku, Kobe, 650-0047, Japan.
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19
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Hackl A, Zed SEDA, Diefenhardt P, Binz-Lotter J, Ehren R, Weber LT. The role of the immune system in idiopathic nephrotic syndrome. Mol Cell Pediatr 2021; 8:18. [PMID: 34792685 PMCID: PMC8600105 DOI: 10.1186/s40348-021-00128-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Accepted: 11/09/2021] [Indexed: 12/12/2022] Open
Abstract
Idiopathic nephrotic syndrome (INS) in children is characterized by massive proteinuria and hypoalbuminemia and usually responds well to steroids. However, relapses are frequent, which can require multi-drug therapy with deleterious long-term side effects. In the last decades, different hypotheses on molecular mechanisms underlying INS have been proposed and several lines of evidences strongly indicate a crucial role of the immune system in the pathogenesis of non-genetic INS. INS is traditionally considered a T-cell-mediated disorder triggered by a circulating factor, which causes the impairment of the glomerular filtration barrier and subsequent proteinuria. Additionally, the imbalance between Th17/Tregs as well as Th2/Th1 has been implicated in the pathomechanism of INS. Interestingly, B-cells have gained attention, since rituximab, an anti-CD20 antibody demonstrated a good therapeutic response in the treatment of INS. Finally, recent findings indicate that even podocytes can act as antigen-presenting cells under inflammatory stimuli and play a direct role in activating cellular pathways that cause proteinuria. Even though our knowledge on the underlying mechanisms of INS is still incomplete, it became clear that instead of a traditionally implicated cell subset or one particular molecule as a causative factor for INS, a multi-step control system including soluble factors, immune cells, and podocytes is necessary to prevent the occurrence of INS. This present review aims to provide an overview of the current knowledge on this topic, since advances in our understanding of the immunopathogenesis of INS may help drive new tailored therapeutic approaches forward.
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Affiliation(s)
- Agnes Hackl
- Department of Pediatrics, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany. .,Department of Internal Medicine II and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.
| | - Seif El Din Abo Zed
- Department of Pediatrics, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.,Department of Internal Medicine II and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Paul Diefenhardt
- Department of Internal Medicine II and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Julia Binz-Lotter
- Department of Internal Medicine II and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Rasmus Ehren
- Department of Pediatrics, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Lutz Thorsten Weber
- Department of Pediatrics, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
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20
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Pukajło-Marczyk A, Zwolińska D. Involvement of Hemopexin in the Pathogenesis of Proteinuria in Children with Idiopathic Nephrotic Syndrome. J Clin Med 2021; 10:3160. [PMID: 34300326 PMCID: PMC8303445 DOI: 10.3390/jcm10143160] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 06/29/2021] [Accepted: 07/15/2021] [Indexed: 01/01/2023] Open
Abstract
Hemopexin (Hpx) is considered a factor in the pathogenesis of idiopathic nephrotic syndrome (INS). The aim of the study was to evaluate the serum and urine values of Hpx (sHpx and uHpx) in children with INS, analyze the role of Hpx, and assess its usefulness as a marker of the disease course. 51 children with INS and 18 age-matched controls were examined. Patients were divided into subgroups depending on the number of relapses (group IA-the first episode of INS, group IB-with relapses) and according to method of treatment (group IIA treated with gluco-corticosteroids (GCS), group IIB treated with GCS and other immunosuppressants). Hpx concentrations were determined by enzyme-linked immunosorbent assay (ELISA). sHpx and uHpx values in relapse were elevated in the whole INS group versus controls (p < 0.000). In remission their levels decreased, but still remained higher than in the control group (p < 0.000). In group IB uHpx levels were increased during remission as compared to group IA (p < 0.006). No significant impact of immuno-suppressants on sHpx was observed, but uHpx excretion in group IIA was higher in relapse (p < 0.026) and lower in remission (p < 0.0017) as compared to group IIB. The results suggest the role of Hpx in the pathogenesis of INS. Hpx may be a useful indicator for continuation of treatment, but it requires confirmation by further controlled studies.
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Affiliation(s)
- Agnieszka Pukajło-Marczyk
- Department of Pediatric Nephrology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw, Poland;
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21
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Chen J, Qiao XH, Mao JH. Immunopathogenesis of idiopathic nephrotic syndrome in children: two sides of the coin. World J Pediatr 2021; 17:115-122. [PMID: 33660135 DOI: 10.1007/s12519-020-00400-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 11/25/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Idiopathic nephrotic syndrome is a common form of glomerular nephropathy in children, with an incidence rate of 1.15-16.9/100,000 depending on different nationalities and ethnicities. The etiological factors and mechanisms of childhood idiopathic nephrotic syndrome have not yet been fully elucidated. This review summarizes the progress of the immunopathogenesis of idiopathic nephrotic syndrome in children. DATA SOURCES We review the literature on the immunopathogenesis of idiopathic nephrotic syndrome in children. Databases including Medline, Scopus, and Web of Science were searched for studies published in any language with the terms "children", "idiopathic nephrotic syndrome", "immunopathogenesis", "T cells", "circulating permeability factors", and "B cells". RESULTS Dysfunction in T lymphocytes and pathogenic circulatory factors were indicated to play key roles in the pathogenesis of idiopathic nephrotic syndrome. Recently, some studies have shown that cellular immune dysfunction may also be involved in the pathogenesis of idiopathic nephrotic syndrome. CONCLUSIONS Both T- and B-cell dysfunction may play significant roles in the pathogenesis of idiopathic nephrotic syndrome, like two sides of one coin, but the role of B cell seems more important than T cells.
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Affiliation(s)
- Jing Chen
- Department of Nephrology, Ningbo Women and Children's Hospital, 339 LiutingRd, Ningbo, 315012, China
| | - Xiao-Hui Qiao
- Department of Nephrology, Ningbo Women and Children's Hospital, 339 LiutingRd, Ningbo, 315012, China.
| | - Jian-Hua Mao
- Department of Nephrology, Children's Hospital, Zhejiang University School of Medicine, 57 Zhuganxiang, Hangzhou, 310003, China
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22
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Zheng Y, Hou L, Wang XL, Zhao CG, Du Y. A review of nephrotic syndrome and atopic diseases in children. Transl Androl Urol 2021; 10:475-482. [PMID: 33532335 PMCID: PMC7844495 DOI: 10.21037/tau-20-665] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Pediatric nephrotic syndrome (NS) is a common and recurrent glomerular disease in childhood. Furthermore, 50–70% of children with NS have increased total IgE in peripheral blood and a variety of clinical manifestations of atopic diseases. Hence, NS has many similarities with atopic diseases. However, no study has revealed a clear link between these two diseases. The present review discusses the correlation between pediatric NS and atopic diseases in children from three aspects: pathogenesis, cytokine change, and treatment. There are similar changes in T cells in terms of pathogenesis, with Th1/Th2 dysfunction and Treg cell function downregulation. Cytokine changes are similar and manifest as an increase in Th2 cytokines, TNF-α and TGF-β1, and a decrease in IL-10. Glucocorticoids, immunosuppressants and biological agents are used for the treatment of these two diseases. Therefore, it was speculated that NS and atopic diseases may be the same kind of disease, have a similar pathogenesis, and only exhibit different clinical manifestations due to different affected parts of the disease.
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Affiliation(s)
- Yue Zheng
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Ling Hou
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Xiu-Li Wang
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Cheng-Guang Zhao
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yue Du
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
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Chen Y, Wang Z, Li Q, Yu L, Zhu Y, Wang J, Sun S. oxLDL promotes podocyte migration by regulating CXCL16, ADAM10 and ACTN4. Mol Med Rep 2020; 22:1976-1984. [PMID: 32705248 PMCID: PMC7411416 DOI: 10.3892/mmr.2020.11292] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 05/22/2020] [Indexed: 01/19/2023] Open
Abstract
Nephrotic syndrome (NS) is one of the most common causes of chronic kidney disease in the pediatric population. Hyperlipidemia is one of the main features of NS. The present study investigated the role of CXC motif chemokine ligand 16 (CXCL16) and ADAM metallopeptidase domain 10 (ADAM10) in oxidized low-density lipoprotein (oxLDL)-stimualted podocytes and the underlying mechanisms. CXCL16 and ADAM10 expression levels in oxLDL-treated podocytes were measured via reverse transcription-quantitative PCR and western blotting. Cell migration assays were conducted to assess the migration of oxLDL-treated podocytes. CXCL16 or ADAM10 overexpression and knockdown assays were conducted. The results indicated that oxLDL stimulation increased ADAM10 and CXCL16 expression levels, and enhanced podocyte migration compared with the control group. Moreover, CXCL16 and ADAM10 overexpression significantly increased podocyte migration and the expression of actinin-α4 (ACTN4) compared with the control groups. By contrast, CXCL16 and ADAM10 knockdown significantly reduced podocyte migration and the expression of ACTN4 compared with the control groups. The results suggested that oxLDL promoted podocyte migration by regulating CXCL16 and ADAM10 expression, as well as by modulating the actin cytoskeleton. Therefore, CXCL16 and ADAM10 may serve as novel therapeutic targets for primary nephrotic syndrome in children.
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Affiliation(s)
- Yuan Chen
- Department of Pediatrics, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250021, P.R. China
| | - Zhiyi Wang
- Department of Hepatobiliary Surgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, P.R. China
| | - Qian Li
- Department of Pediatrics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, P.R. China
| | - Lichun Yu
- Department of Pediatrics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, P.R. China
| | - Yanji Zhu
- Department of Pediatrics, People's Hospital of Rizhao, Rizhao, Shandong 276800, P.R. China
| | - Jing Wang
- Department of Pediatrics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, P.R. China
| | - Shuzhen Sun
- Department of Pediatrics, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250021, P.R. China
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24
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Chizinga M, Hussain M, Taylor K, Kalra S, Gupte A, Canales M. First case of minimal change nephrotic syndrome resolving with antifungal therapy for isolated pleural cryptococcal infection. IDCases 2020; 21:e00838. [PMID: 32509527 PMCID: PMC7265054 DOI: 10.1016/j.idcr.2020.e00838] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 05/19/2020] [Accepted: 05/19/2020] [Indexed: 11/30/2022] Open
Abstract
We report the case of a 71-year-old male with poorly controlled diabetes mellitus who presented with lower extremity edema and acute renal failure. He was diagnosed with nephrotic syndrome secondary to minimal change disease (MCD). Treatment with steroids was withheld due to concern for hyperglycemia in the context of his poorly controlled diabetes mellitus. A week after discharge, he was subsequently re-hospitalized four times within a month with pleural effusions, dyspnea, and fever. Work up revealed isolated pleural cryptococcosis, demonstrated on two separate admissions. There was neither evidence of disseminated disease nor immunocompromising condition. Immunosuppression was not initiated for the treatment of MCD in the setting of poorly controlled diabetes and active infection. After six months of treatment with fluconazole 400 mg/day, the nephrotic syndrome, renal failure, and cryptococcal pleuritis resolved. This case is the first to our knowledge of isolated pleural cryptococcosis associated with nephrotic syndrome. The patient’s course lends further support to the hypothesis that there may be causal relationship between cryptococcosis and nephrotic syndrome.
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Affiliation(s)
- Mwelwa Chizinga
- Division of Pulmonary& Critical Care, University of Florida, College of Medicine, United States
| | - Manzar Hussain
- Division of Nephrology, University of Florida, College of Medicine, United States
| | - Katie Taylor
- Division of Infectious Diseases and Global Medicine, University of Florida, College of Medicine, United States
| | - Saminder Kalra
- Division of Pulmonary& Critical Care, University of Florida, College of Medicine, United States
| | - Asmita Gupte
- Division of Infectious Diseases and Global Medicine, University of Florida, College of Medicine, United States.,Malcom Randall VA Medical center, Gainesville, Florida
| | - Muna Canales
- Division of Nephrology, University of Florida, College of Medicine, United States.,Malcom Randall VA Medical center, Gainesville, Florida
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Keisuke S, Kohei M, Takuji E, Tomoki M, Yuichi M, Rina O, Tsukasa T, Mitsuru O. Role of cathepsin L in idiopathic nephrotic syndrome in children. Med Hypotheses 2020; 141:109718. [PMID: 32289645 DOI: 10.1016/j.mehy.2020.109718] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 04/06/2020] [Indexed: 01/12/2023]
Abstract
Nephrotic syndrome (NS) is one of the most common glomerular diseases in children. Glomerular podocyte dysfunction can result in proteinuria, the presence of a large amount of protein in the urine. Podocytes are unique epithelial cells that divide into 3 separate structural and functional segments: a cell body, major processes, and foot processes. Since synaptopodin, dynamin, and actin are crucial components of the podocyte cytoskeleton, degradation of these proteins is associated with cytoskeleton instability, resulting in the development of proteinuria. Cathepsin L (CatL), a cysteine proteinase, plays a crucial role in various renal diseases. CatL expression is elevated in rats with puromycin aminonucleoside-induced nephropathy, which is used as a model of minimal change NS. In CatL-deficient mice, which do not develop proteinuria, dynamin is retained through the escape of CatL-mediated decomposition, resulting in no changes in the filtration barrier of podocytes. However, there is limited information on the roles of CatL in NS. Based on these data, CatL might play an important role in the development of proteinuria. Furthermore, identifying the functions of CatL may contribute to a better understanding of the pathogenesis of childhood-onset NS. We hypothesize that high levels of CatL can lead to cytoskeletal instability of podocytes, resulting in proteinuria in childhood-onset NS.
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Affiliation(s)
- Sugimoto Keisuke
- Department of Pediatrics, Kindai University, Faculty of Medicine, Osaka, Japan.
| | - Miyazaki Kohei
- Department of Pediatrics, Kindai University, Faculty of Medicine, Osaka, Japan
| | - Enya Takuji
- Department of Pediatrics, Kindai University, Faculty of Medicine, Osaka, Japan
| | - Miyazawa Tomoki
- Department of Pediatrics, Kindai University, Faculty of Medicine, Osaka, Japan
| | - Morimoto Yuichi
- Department of Pediatrics, Kindai University, Faculty of Medicine, Osaka, Japan
| | - Oshima Rina
- Department of Pediatrics, Kindai University, Faculty of Medicine, Osaka, Japan
| | - Takemura Tsukasa
- Department of Pediatrics, Kushimoto Municipality Hospital, Wakayama, Japan
| | - Okada Mitsuru
- Department of Pediatrics, Kindai University, Faculty of Medicine, Osaka, Japan
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Evidences for Expression and Location of ANGPTL8 in Human Adipose Tissue. J Clin Med 2020; 9:jcm9020512. [PMID: 32069954 PMCID: PMC7074245 DOI: 10.3390/jcm9020512] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Accepted: 02/10/2020] [Indexed: 12/25/2022] Open
Abstract
The metabolism of triglycerides (TGs) is regulated, among others, by the lipoprotein lipase (LPL) that hydrolyses the TGs on endothelial cells. In turn, LPL is inhibited by the ANGPTLs family of proteins, such as ANGPTL3, 4, and, 8; the latter is the least known. In this work, we have tried to establish the expression and localisation of the Angiopoietin-like 8 (ANGPTL8) protein in the visceral adipose tissue (VAT) of morbid-obese and non-obese patients. 109 subjects (66 women and 43 men) undergoing laparoscopic surgery participated in this study. A blood sample and a portion of the VAT were obtained, and the patients were classified according to their Body Mass Index (BMI) as non-obese (19.5–30 kg/m2) and morbid-obese (40–50 kg/m2). No significant changes in ANGPTL8 plasma levels were determined by EIA in obese patients. The immunocytochemistry and Western blotting showed the presence of increased ANGPTL8 in morbid-obese patients (p < 0.05). In-situ hybridisation and a real time polymerase chain reaction (RT-PCR) confirmed that the mRNA that encodes ANGPTL8 was present in adipocytes, without differences in their nutritional state (p = 0.89), and even in the endothelial cells. Our data suggests that ANGPT8 plasmatic levels do not change significantly in patients with morbid obesity, although there is a modest difference related to gender. Besides, we demonstrate that in visceral adipose tissue, ANGPTL8 is well defined in the cytoplasm of adipocytes coexisting with perilipin-1 and its mRNA, also is present in endothelial cells. These findings suggest the possibility that among other functions, ANGPTL8 could perform either a paracrine and/or an endocrine role in the adipose tissue.
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Nephrotic syndrome in a dish: recent developments in modeling in vitro. Pediatr Nephrol 2020; 35:1363-1372. [PMID: 30820702 PMCID: PMC7316697 DOI: 10.1007/s00467-019-4203-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 12/20/2018] [Accepted: 01/16/2019] [Indexed: 01/05/2023]
Abstract
Nephrotic syndrome is a heterogeneous disease, and one of the most frequent glomerular disorders among children. Depending on the etiology, it may result in end-stage renal disease and the need for renal replacement therapy. A dysfunctional glomerular filtration barrier, comprising of endothelial cells, the glomerular basement membrane and podocytes, characterizes nephrotic syndrome. Podocytes are often the primary target cells in the pathogenesis, in which not only the podocyte function but also their crosstalk with other glomerular cell types can be disturbed due to a myriad of factors. The pathophysiology of nephrotic syndrome is highly complex and studying molecular mechanisms in vitro requires state-of-the-art cell-based models resembling the in vivo situation and preferably a fully functional glomerular filtration barrier. Current advances in stem cell biology and microfluidic platforms have heralded a new era of three-dimensional (3D) cultures that might have the potential to recapitulate the glomerular filtration barrier in vitro. Here, we highlight the molecular basis of nephrotic syndrome and discuss requirements to accurately study nephrotic syndrome in vitro, including an overview of specific podocyte markers, cutting-edge stem cell organoids, and the implementation of microfluidic platforms. The development of (patho) physiologically relevant glomerular models will accelerate the identification of molecular targets involved in nephrotic syndrome and may be the harbinger of a new era of therapeutic avenues.
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Al Rushood M, Al-Eisa AA, Haider MZ. Interleukin-4 and Interleukin-13 Gene Polymorphisms in Children With Idiopathic Nephrotic Syndrome. Front Pediatr 2020; 8:591349. [PMID: 33330285 PMCID: PMC7710803 DOI: 10.3389/fped.2020.591349] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 10/28/2020] [Indexed: 11/23/2022] Open
Abstract
Background: Idiopathic Nephrotic syndrome (INS) is an immune-mediated disease in which a number of cytokines, including IL-4 and IL-13, have been implicated in the pathogenesis. Cytokine gene polymorphisms might affect their levels and activity. Therefore, may affect INS susceptibility and response to treatment. The aim of the study was to determine the association of IL-4 and IL-13 gene polymorphisms and INS susceptibility and their effects on steroid responsiveness in children. Methods: The polymorphisms in IL-4 and IL-13 genes were detected by PCR-RFLP in 155 INS patients and 64 controls. Results: A total of 132 steroid-sensitive (SS) and 23 steroid resistance (SR) INS patients; mean age 7.3 ± 4.0 years, were included. Male: Female ratio was 2:1. No significant statistical differences were detected in the frequency of CC, CT, and TT genotypes of IL-4 gene compared to controls (P = 0.57, 0.61, and 1.00, respectively). There was no significant difference in the T and C-allele frequencies, in SS and SR subgroups. Analysis of IL-13 gene polymorphism also did not show significant statistical differences in the frequency of QQ, RQ, and RR genotypes compared to controls (P = 0.74, 1.00, and 0.68, respectively). No significant difference was found in the Q and R-allele frequency. However, the heterozygous RQ genotype of the IL13 gene was significantly higher in SS INS patients compared to the SR INS cases (P = 0.04). Conclusion: Our findings did not show an association between IL-4 and IL-13 gene polymorphisms and INS susceptibility. However, IL-13 RQ genotype was expressed more in children with INS who are steroid sensitive.
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Affiliation(s)
- Maysoun Al Rushood
- Department of Pediatrics, Faculty of Medicine, Health Sciences Center, Kuwait University, Kuwait City, Kuwait
| | - Amal A Al-Eisa
- Department of Pediatrics, Faculty of Medicine, Health Sciences Center, Kuwait University, Kuwait City, Kuwait
| | - Mohammad Z Haider
- Department of Pediatrics, Faculty of Medicine, Health Sciences Center, Kuwait University, Kuwait City, Kuwait
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Bensimhon AR, Williams AE, Gbadegesin RA. Treatment of steroid-resistant nephrotic syndrome in the genomic era. Pediatr Nephrol 2019; 34:2279-2293. [PMID: 30280213 PMCID: PMC6445770 DOI: 10.1007/s00467-018-4093-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 09/13/2018] [Accepted: 09/18/2018] [Indexed: 12/25/2022]
Abstract
The pathogenesis of steroid-resistant nephrotic syndrome (SRNS) is not completely known. Recent advances in genomics have elucidated some of the molecular mechanisms and pathophysiology of the disease. More than 50 monogenic causes of SRNS have been identified; however, these genes are responsible for only a small fraction of SRNS in outbred populations. There are currently no guidelines for genetic testing in SRNS, but evidence from the literature suggests that testing should be guided by the genetic architecture of the disease in the population. Notably, most genetic forms of SRNS do not respond to current immunosuppressive therapies; however, a small subset of patients with monogenic SRNS will achieve partial or complete remission with specific immunomodulatory agents, presumably due to non-immunosuppressive effects of these agents. We suggest a pragmatic approach to the therapy of genetic SRNS, as there is no evidence-based algorithm for the management of the disease.
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Affiliation(s)
- Adam R. Bensimhon
- Department of Pediatrics, Division of Nephrology, Duke University Medical Center, Durham, NC 27710, USA
| | - Anna E. Williams
- Department of Pediatrics, Division of Nephrology, Duke University Medical Center, Durham, NC 27710, USA
| | - Rasheed A. Gbadegesin
- Department of Pediatrics, Division of Nephrology, Duke University Medical Center, Durham, NC 27710, USA,Department of Medicine, Division of Nephrology, Duke University Medical Center, Durham, NC 27710, USA,Duke Molecular Physiology Institute, Durham, NC, USA
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30
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Molecular stratification of idiopathic nephrotic syndrome. Nat Rev Nephrol 2019; 15:750-765. [DOI: 10.1038/s41581-019-0217-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2019] [Indexed: 01/03/2023]
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31
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Dryer SE, Roshanravan H, Kim EY. TRPC channels: Regulation, dysregulation and contributions to chronic kidney disease. Biochim Biophys Acta Mol Basis Dis 2019; 1865:1041-1066. [PMID: 30953689 DOI: 10.1016/j.bbadis.2019.04.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 12/20/2018] [Accepted: 01/06/2019] [Indexed: 12/13/2022]
Abstract
Mutations in the gene encoding canonical transient receptor potential-6 (TRPC6) channels result in severe nephrotic syndromes that typically lead to end-stage renal disease. Many but not all of these mutations result in a gain in the function of the resulting channel protein. Since those observations were first made, substantial work has supported the hypothesis that TRPC6 channels can also contribute to progression of acquired (non-genetic) glomerular diseases, including primary and secondary FSGS, glomerulosclerosis during autoimmune glomerulonephritis, and possibly in type-1 diabetes. Their regulation has been extensively studied, especially in podocytes, but also in mesangial cells and other cell types present in the kidney. More recent evidence has implicated TRPC6 in renal fibrosis and tubulointerstitial disease caused by urinary obstruction. Consequently TRPC6 is being extensively investigated as a target for drug discovery. Other TRPC family members are present in kidney. TRPC6 can form a functional heteromultimer with TRPC3, and it has been suggested that TRPC5 may also play a role in glomerular disease progression, although the evidence on this is contradictory. Here we review literature on the expression and regulation of TRPC6, TRPC3 and TRPC5 in various cell types of the vertebrate kidney, the evidence that these channels are dysregulated in disease models, and research showing that knock-out or pharmacological inhibition of these channels can reduce the severity of kidney disease. We also summarize several areas that remain controversial, and some of the large gaps of knowledge concerning the fundamental role of these proteins in regulation of renal function.
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Affiliation(s)
- Stuart E Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA; Department of Internal Medicine, Division of Nephrology, Baylor College of Medicine, Houston, TX, USA.
| | - Hila Roshanravan
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Eun Young Kim
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
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32
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Lane BM, Cason R, Esezobor CI, Gbadegesin RA. Genetics of Childhood Steroid Sensitive Nephrotic Syndrome: An Update. Front Pediatr 2019; 7:8. [PMID: 30761277 PMCID: PMC6361778 DOI: 10.3389/fped.2019.00008] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 01/11/2019] [Indexed: 12/12/2022] Open
Abstract
Advances in genome science in the last 20 years have led to the discovery of over 50 single gene causes and genetic risk loci for steroid resistant nephrotic syndrome (SRNS). Despite these advances, the genetic architecture of childhood steroid sensitive nephrotic syndrome (SSNS) remains poorly understood due in large part to the varying clinical course of SSNS over time. Recent exome and genome wide association studies from well-defined cohorts of children with SSNS identified variants in multiple MHC class II molecules such as HLA-DQA1 and HLA-DQB1 as risk factors for SSNS, thus stressing the central role of adaptive immunity in the pathogenesis of SSNS. However, evidence suggests that unknown second hit risk loci outside of the MHC locus and environmental factors also make significant contributions to disease. In this review, we examine what is currently known about the genetics of SSNS, the implications of recent findings on our understanding of pathogenesis of SSNS, and how we can utilize these results and findings from future studies to improve the management of children with nephrotic syndrome.
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Affiliation(s)
- Brandon M Lane
- Division of Nephrology, Departments of Pediatrics, Duke University Medical Center, Durham, NC, United States.,Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, United States
| | - Rachel Cason
- Division of Nephrology, Departments of Pediatrics, Duke University Medical Center, Durham, NC, United States
| | | | - Rasheed A Gbadegesin
- Division of Nephrology, Departments of Pediatrics, Duke University Medical Center, Durham, NC, United States.,Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, United States
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33
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Trachtman H, Gipson DS, Lemley KV, Troost JP, Faul C, Morrison DJ, Vento SM, Ahn DH, Goldberg JD. Plasma Zonulin Levels in Childhood Nephrotic Syndrome. Front Pediatr 2019; 7:197. [PMID: 31157195 PMCID: PMC6532587 DOI: 10.3389/fped.2019.00197] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 04/29/2019] [Indexed: 01/01/2023] Open
Abstract
Objective: We conducted this study to test the hypothesis that plasma zonulin levels are elevated in pediatric patients with nephrotic syndrome compared to healthy controls. Study Design: Plasma zonulin levels were measured by ELISA in 114 children enrolled in the NEPTUNE study. Clinical and laboratory data were retrieved from the NEPTUNE database. Results: The median age of the patients was 10 (IQR = 5 to 14) years, 59 were male, 64 had minimal change disease, 47 focal segmental glomerulosclerosis, median eGFR was 96 (IQR = 80 to 114) ml/min/1.73 m2, and median urine protein:creatinine ratio was 0.5 (IQR = 0.1 to 3.4) (g:g). The plasma zonulin level was 14.2 ± 5.0 vs. 10.2 ± 2.5 ng/ml in healthy adults in a report using the same assay kit, P = 0.0025. These findings were confirmed in an independent cohort of children with nephrotic syndrome compared to healthy age-matched controls, P = 0.01. Zonulin concentrations did not differ in children with minimal change disease vs. focal segmental glomerulosclerosis, frequently relapsing vs. steroid-dependent vs. steroid-resistant clinical course, and were not influenced by the immunosuppressive treatment regimen. There was no relationship between plasma zonulin levels and the absolute or percentage change in proteinuria from enrollment until the time of the zonulin assay. Conclusion: Plasma zonulin levels are elevated in childhood nephrotic syndrome regardless of level of proteinuria or specific treatment. The cause of the high plasma zonulin levels and whether zonulin contributes to glomerular injury requires further study.
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Affiliation(s)
- Howard Trachtman
- Division of Nephrology, Department of Pediatrics, NYU School of Medicine, New York, NY, United States
| | - Debbie S Gipson
- Division of Nephrology, Department of Pediatrics, University of Michigan, Ann Arbor, MI, United States
| | - Kevin V Lemley
- Division of Nephrology, Department of Pediatrics, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Jonathan P Troost
- Division of Nephrology, Department of Pediatrics, University of Michigan, Ann Arbor, MI, United States
| | - Christian Faul
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | | | - Suzanne M Vento
- Division of Nephrology, Department of Pediatrics, NYU School of Medicine, New York, NY, United States
| | - Dong-Hyun Ahn
- Department of Population Health, NYU School of Medicine, New York, NY, United States
| | - Judith D Goldberg
- Department of Population Health, NYU School of Medicine, New York, NY, United States
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Kienzl‐Wagner K, Rosales A, Scheidl S, Giner T, Bösmüller C, Rudnicki M, Oberhuber R, Margreiter C, Soleiman A, Öfner D, Waldegger S, Schneeberger S. Successful management of recurrent focal segmental glomerulosclerosis. Am J Transplant 2018; 18:2818-2822. [PMID: 29962080 PMCID: PMC6220932 DOI: 10.1111/ajt.14998] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 06/20/2018] [Accepted: 06/22/2018] [Indexed: 01/25/2023]
Abstract
Primary focal segmental glomerulosclerosis (FSGS) recurs in up to 55% of patients after kidney transplantation. Herein we report the successful management of recurrent FSGS. A 5-year-old boy with primary FSGS received a deceased donor renal transplant. Immediate and fulminant recurrence of FSGS caused anuric graft failure that was resistant to plasmapheresis and rituximab. After exclusion of structural or immunologic damage to the kidney by repeated biopsies, the allograft was retrieved from the first recipient on day 27 and transplanted into a 52-year-old second recipient who had vascular nephropathy. Immediately after retransplantation, the allograft regained function with excellent graft function persistent now at 3 years after transplant. After 2 years on hemodialysis, the boy was listed for kidney retransplantation. To prevent FSGS recurrence, pretreatment with ofatumumab was performed. Nephrotic range proteinuria still occurred after the second transplantation, which responded, however, to daily plasma exchange in combination with ofatumumab. At 8 months after kidney retransplantation graft function is good. The clinical course supports the hypothesis of a circulating permeability factor in the pathogenesis of FSGS. Successful ofatumumab pretreatment implicates a key role of B cells. Herein we provide a description of successful management of kidney failure by FSGS, carefully avoiding waste of organs.
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Affiliation(s)
- Katrin Kienzl‐Wagner
- Department of Visceral, Transplant and Thoracic SurgeryMedical University of InnsbruckInnsbruckAustria
| | - Alejandra Rosales
- Department of PediatricsMedical University of InnsbruckInnsbruckAustria
| | - Stefan Scheidl
- Department of Visceral, Transplant and Thoracic SurgeryMedical University of InnsbruckInnsbruckAustria
| | - Thomas Giner
- Department of PediatricsMedical University of InnsbruckInnsbruckAustria
| | - Claudia Bösmüller
- Department of Visceral, Transplant and Thoracic SurgeryMedical University of InnsbruckInnsbruckAustria
| | - Michael Rudnicki
- Department of Internal MedicineMedical University of InnsbruckInnsbruckAustria
| | - Rupert Oberhuber
- Department of Visceral, Transplant and Thoracic SurgeryMedical University of InnsbruckInnsbruckAustria
| | - Christian Margreiter
- Department of Visceral, Transplant and Thoracic SurgeryMedical University of InnsbruckInnsbruckAustria
| | | | - Dietmar Öfner
- Department of Visceral, Transplant and Thoracic SurgeryMedical University of InnsbruckInnsbruckAustria
| | | | - Stefan Schneeberger
- Department of Visceral, Transplant and Thoracic SurgeryMedical University of InnsbruckInnsbruckAustria
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35
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Siligato R, Cernaro V, Nardi C, De Gregorio F, Gembillo G, Costantino G, Conti G, Buemi M, Santoro D. Emerging therapeutic strategies for minimal change disease and focal and segmental glomerulosclerosis. Expert Opin Investig Drugs 2018; 27:839-879. [PMID: 30360670 DOI: 10.1080/13543784.2018.1540587] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
INTRODUCTION Minimal change disease (MCD) and Focal and segmental glomerulosclerosis (FSGS) are two of the major causes of nephrotic syndrome (NS) in children and adults. According to KDIGO (Kidney Disease: Improving Global Outcomes) guidelines, the treatment of adult primary MCD and FSGS should be based on immunosuppressants and antiproteinuric drugs. Recently, Rituximab, a humanized monoclonal antibody (mAb) has emerged as a potential treatment for steroid or calcineurin inhibitor-dependent patients; it has however demonstrated lower efficacy in those with nephrotic syndrome that is resistant to the above indicated drugs. AREAS COVERED Analysis of ongoing and already completed clinical trials, retrieved from clinicaltrials.gov, clinicaltrialsregister.eu and PubMed involving new therapies for nephrotic syndrome secondary to MCD and FSGS. EXPERT OPINION The most promising drugs under investigation for MCD and FSGS are mAbs. We are hopeful that new therapeutic options to treat multi-drug resistant MCD and FSGS will emerge from currently ongoing studies. What appears certain is the difficulty in enrolling patients affected by orphan renal diseases and the selection of valid endpoints in clinical trials, such as kidney failure.
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Affiliation(s)
- Rossella Siligato
- a Unit of Nephrology and Dialysis, Department of Internal Medicine , Messina , Italy
| | - Valeria Cernaro
- a Unit of Nephrology and Dialysis, Department of Internal Medicine , Messina , Italy
| | - Chiara Nardi
- a Unit of Nephrology and Dialysis, Department of Internal Medicine , Messina , Italy
| | - Francesca De Gregorio
- a Unit of Nephrology and Dialysis, Department of Internal Medicine , Messina , Italy
| | - Guido Gembillo
- a Unit of Nephrology and Dialysis, Department of Internal Medicine , Messina , Italy
| | - Giuseppe Costantino
- a Unit of Nephrology and Dialysis, Department of Internal Medicine , Messina , Italy
| | - Giovanni Conti
- b Unit of Pediatric Nephrology and Rheumatology , University of Messina , Messina , Italy
| | - Michele Buemi
- a Unit of Nephrology and Dialysis, Department of Internal Medicine , Messina , Italy
| | - Domenico Santoro
- a Unit of Nephrology and Dialysis, Department of Internal Medicine , Messina , Italy
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Tullus K, Webb H, Bagga A. Management of steroid-resistant nephrotic syndrome in children and adolescents. THE LANCET CHILD & ADOLESCENT HEALTH 2018; 2:880-890. [PMID: 30342869 DOI: 10.1016/s2352-4642(18)30283-9] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 08/18/2018] [Accepted: 08/21/2018] [Indexed: 02/08/2023]
Abstract
More than 85% of children and adolescents (majority between 1-12 years old) with idiopathic nephrotic syndrome show complete remission of proteinuria following daily treatment with corticosteroids. Patients who do not show remission after 4 weeks' treatment with daily prednisolone are considered to have steroid-resistant nephrotic syndrome (SRNS). Renal histology in most patients shows presence of focal segmental glomerulosclerosis, minimal change disease, and (rarely) mesangioproliferative glomerulonephritis. A third of patients with SRNS show mutations in one of the key podocyte genes. The remaining cases of SRNS are probably caused by an undefined circulating factor. Treatment with calcineurin inhibitors (ciclosporin and tacrolimus) is the standard of care for patients with non-genetic SRNS, and approximately 70% of patients achieve a complete or partial remission and show satisfactory long-term outcome. Additional treatment with drugs that inhibit the renin-angiotensin axis is recommended for hypertension and for reducing remaining proteinuria. Patients with SRNS who do not respond to treatment with calcineurin inhibitors or other immunosuppressive drugs can show declining kidney function and are at risk for end-stage renal failure. Approximately a third of those who undergo renal transplantation show recurrent focal segmental glomerulosclerosis in the allograft and often respond to combined treatment with plasma exchange, rituximab, and intensified immunosuppression.
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Affiliation(s)
- Kjell Tullus
- Nephrology Unit, Great Ormond Street Hospital for Children, Great Ormond Street, London, UK.
| | - Hazel Webb
- Nephrology Unit, Great Ormond Street Hospital for Children, Great Ormond Street, London, UK
| | - Arvind Bagga
- Division of Nephrology, Indian Council of Medical Research Advanced Center for Research in Nephrology, All India Institute of Medical Sciences, New Delhi, India
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Abramowicz D, Oberbauer R, Heemann U, Viklicky O, Peruzzi L, Mariat C, Crespo M, Budde K, Oniscu GC. Recent advances in kidney transplantation: a viewpoint from the Descartes advisory board. Nephrol Dial Transplant 2018; 33:1699-1707. [PMID: 29342289 PMCID: PMC6168736 DOI: 10.1093/ndt/gfx365] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 11/10/2017] [Indexed: 02/06/2023] Open
Abstract
Transplantation medicine is a rapidly evolving field. Keeping afloat of the published literature to offer the best clinical care to our patients is a daunting task. As part of its educational mission, the Descartes advisory board identified seven topics in kidney transplantation where there has been substantial progresses over the last years: kidney allocation within Eurotransplant; kidney exchange strategies; kidney machine perfusion strategies; the changing landscape of anti-human leukocyte antigen (HLA) antibodies; the new immunosuppressive drugs in the pipeline; strategies for immunosuppression minimization; and the continuous enigma of focal segmental glomerular sclerosis recurrence after transplantation. Here, we have summarized the main knowledge and the main challenges of these seven topics with the aim to provide transplant professionals at large with key bullet points to successfully understand these new concepts.
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Affiliation(s)
- Daniel Abramowicz
- Department of Nephrology, Universitair Ziekenhuis Antwerpen, Edegem, Belgium
| | - Rainer Oberbauer
- Department of Nephrology, Medical University of Vienna, Vienna, Austria
- Department of Nephrology, KH Elisabethinen, Linz, Austria
| | - Uwe Heemann
- Department of Nephrology, Klinikum Rechts der Isar, München, Germany
| | - Ondrej Viklicky
- Department of Nephrology, Institute for Clinical and Experimental Medicine, Prague 4, Czech Republic
| | - Licia Peruzzi
- Nephrology and Dialysis Department, Regina Margherita Hospital, Torino, Italy
| | - Christophe Mariat
- Department of Nephrological Intensive Care, University Jean Monnet, Saint Etienne, France
| | - Marta Crespo
- Department of Nephrology, Hospital del Mar Barcelona, Barcelona, Spain
| | - Klemens Budde
- Department of Nephrology, Charité—Universitätsmedizin Berlin, Berlin, Germany
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38
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Mechanisms underlying modulation of podocyte TRPC6 channels by suPAR: Role of NADPH oxidases and Src family tyrosine kinases. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3527-3536. [PMID: 30293571 DOI: 10.1016/j.bbadis.2018.08.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 08/02/2018] [Accepted: 08/06/2018] [Indexed: 01/10/2023]
Abstract
The soluble urokinase receptor (suPAR) has been implicated in the pathogenesis of chronic kidney diseases (CKD) and may function as a circulating "permeability factor" driving primary focal and segmental glomerulosclerosis (FSGS). Here we examined the mechanisms whereby suPAR causes mobilization and increased activation of Ca2+-permeable TRPC6 channels, which are also implicated in FSGS. Treatment of immortalized mouse podocytes with recombinant suPAR for 24 h caused a marked increase in cytosolic reactive oxygen species (ROS) that required signaling through integrins. This effect was associated with increased assembly of active cell surface NADPH oxidase 2 (Nox2) complexes and was blocked by the Nox2 inhibitor apoycynin. Treatment with suPAR also evoked a functionally measurable increase in TRPC6 channels that was blocked by concurrent treatment with the ROS-quencher TEMPOL as well as by inhibition of Rac1, an essential component of active Nox2 complexes. Elevated ROS evoked by exposing cells to suPAR or H2O2 caused a marked increase in the abundance of tyrosine-phosphorylated proteins including Src, and suPAR-evoked Src activation was blocked by TEMPOL. Moreover, mobilization and increased activation of TRPC6 by suPAR or H2O2 was blocked by concurrent exposure to PP2, an inhibitor of Src family tyrosine kinases. These data suggest that suPAR induces oxidative stress in podocytes that in turn drives signaling through Src family kinases to upregulate TRPC6 channels. The combination of oxidative stress and altered Ca2+ signaling may contribute to loss of podocytes and progression of various forms of CKD.
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39
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Debiec H, Dossier C, Letouzé E, Gillies CE, Vivarelli M, Putler RK, Ars E, Jacqz-Aigrain E, Elie V, Colucci M, Debette S, Amouyel P, Elalaoui SC, Sefiani A, Dubois V, Simon T, Kretzler M, Ballarin J, Emma F, Sampson MG, Deschênes G, Ronco P. Transethnic, Genome-Wide Analysis Reveals Immune-Related Risk Alleles and Phenotypic Correlates in Pediatric Steroid-Sensitive Nephrotic Syndrome. J Am Soc Nephrol 2018; 29:2000-2013. [PMID: 29903748 PMCID: PMC6050942 DOI: 10.1681/asn.2017111185] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 04/09/2018] [Indexed: 12/20/2022] Open
Abstract
Background Steroid-sensitive nephrotic syndrome (SSNS) is a childhood disease with unclear pathophysiology and genetic architecture. We investigated the genomic basis of SSNS in children recruited in Europe and the biopsy-based North American NEPTUNE cohort.Methods We performed three ancestry-matched, genome-wide association studies (GWAS) in 273 children with NS (Children Cohort Nephrosis and Virus [NEPHROVIR] cohort: 132 European, 56 African, and 85 Maghrebian) followed by independent replication in 112 European children, transethnic meta-analysis, and conditional analysis. GWAS alleles were used to perform glomerular cis-expression quantitative trait loci studies in 39 children in the NEPTUNE cohort and epidemiologic studies in GWAS and NEPTUNE (97 children) cohorts.Results Transethnic meta-analysis identified one SSNS-associated single-nucleotide polymorphism (SNP) rs1063348 in the 3' untranslated region of HLA-DQB1 (P=9.3×10-23). Conditional analysis identified two additional independent risk alleles upstream of HLA-DRB1 (rs28366266, P=3.7×10-11) and in the 3' untranslated region of BTNL2 (rs9348883, P=9.4×10-7) within introns of HCG23 and LOC101929163 These three risk alleles were independent of the risk haplotype DRB1*07:01-DQA1*02:01-DQB1*02:02 identified in European patients. Increased burden of risk alleles across independent loci was associated with higher odds of SSNS. Increased burden of risk alleles across independent loci was associated with higher odds of SSNS, with younger age of onset across all cohorts, and with increased odds of complete remission across histologies in NEPTUNE children. rs1063348 associated with decreased glomerular expression of HLA-DRB1, HLA-DRB5, and HLA-DQB1.Conclusions Transethnic GWAS empowered discovery of three independent risk SNPs for pediatric SSNS. Characterization of these SNPs provide an entry for understanding immune dysregulation in NS and introducing a genomically defined classification.
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Affiliation(s)
- Hanna Debiec
- Sorbonne Université, UPMC Paris 06, Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche S 1155, Paris, France
| | | | - Eric Letouzé
- Pediatric Pharmacology and Pharmacogenetics, CIC1426, Hôpital Robert Debré, Paris, France
- Université Paris Diderot, Institut Universitaire d'Hématologie, Paris, France
| | - Christopher E Gillies
- Pediatric Nephrology, University of Michigan School of Medicine, Ann Arbor, Michigan
| | - Marina Vivarelli
- Nephrology and Dialysis Department, Istituto di Ricovero e Cura a Carattere Scientifico Ospedale Pediatrico Bambino Gesù, Rome, Italy
| | - Rosemary K Putler
- Pediatric Nephrology, University of Michigan School of Medicine, Ann Arbor, Michigan
| | - Elisabet Ars
- Molecular Biology Laboratory, Fundació Puigvert, Instituto de Investigaciones Biomédicas Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Evelyne Jacqz-Aigrain
- Pediatric Pharmacology and Pharmacogenetics, CIC1426, Hôpital Robert Debré, Paris, France
| | - Valery Elie
- Pediatric Pharmacology and Pharmacogenetics, CIC1426, Hôpital Robert Debré, Paris, France
| | - Manuela Colucci
- Nephrology and Dialysis Department, Istituto di Ricovero e Cura a Carattere Scientifico Ospedale Pediatrico Bambino Gesù, Rome, Italy
| | - Stéphanie Debette
- University of Bordeaux, Institut National de la Santé et de la Recherche Médicale, Bordeaux Population Health Research Center, Unité Mixte de Recherche 1219, CHU Bordeaux, Bordeaux, France
| | - Philippe Amouyel
- University of Lille, Institut National de la Santé et de la Recherche Médicale, CHU Lille, Institut Pasteur de Lille, U1167 RID-AGE, Lille, France
| | - Siham C Elalaoui
- Department of Medical Genetics, Institut National d'Hygiène, Rabat, Morocco
| | - Abdelaziz Sefiani
- Human Genomic Center, Faculté de Médecine et de Pharmacie Rabat, Université Mohamed V. Rabat, Rabat, Morocco
| | - Valérie Dubois
- Etablissement Français du Sang Rhone-Alpes, Lyon, Rhone-Alpes, France
| | - Tabassome Simon
- Assistance Publique-Hôpitaux de Paris, Hôpital Saint Antoine, Department of Clinical Pharmacology, Unité de Recherche Clinique, Paris, France
- Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche S1148, Paris, France
| | - Matthias Kretzler
- Department of Internal Medicine and Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan;
| | - Jose Ballarin
- Department of Nephrology, Fundación Puigvert, Barcelona, Spain
| | - Francesco Emma
- Pediatric Nephrology, University of Michigan School of Medicine, Ann Arbor, Michigan
| | - Matthew G Sampson
- Pediatric Nephrology, University of Michigan School of Medicine, Ann Arbor, Michigan;
| | - Georges Deschênes
- Department of Paediatric Nephrology and
- Institut National de la Santé et de la Recherche Médicale U1149, Unité de Formation et de Recherche de Médecine Xavier Bichat, Université Sorbonne Paris Cité, Paris, France; and
| | - Pierre Ronco
- Sorbonne Université, UPMC Paris 06, Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche S 1155, Paris, France;
- Assistance Publique-Hôpitaux de Paris, Nephrology and Dialysis Department, Tenon Hospital, Paris, France
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40
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Trpc6 inactivation confers protection in a model of severe nephrosis in rats. J Mol Med (Berl) 2018; 96:631-644. [PMID: 29785489 PMCID: PMC6015123 DOI: 10.1007/s00109-018-1648-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 04/25/2018] [Accepted: 05/07/2018] [Indexed: 12/11/2022]
Abstract
Abstract Mutations in canonical transient receptor potential-6 (TRPC6) channels give rise to rare familial forms of focal and segmental glomerulosclerosis (FSGS). Here we examined a possible role for TRPC6 in the progression of chronic puromycin aminonucleoside (PAN) nephrosis in Sprague-Dawley rats, a classic model of acquired nephrotic syndromes. We used CRISPR/Cas9 technology to delete a 239-bp region within exon 2 of the Trpc6 gene (Trpc6del allele). Trpc6del/del rats expressed detectable Trpc6 transcripts missing exon 2, and TRPC6 proteins could be detected by immunoblot of renal cortex. However, the abundance of Trpc6 transcripts and TRPC6 protein in renal cortex was much lower than in Trpc6wt/wt littermates, and functional TRPC6 channels could not be detected in whole-cell recordings from glomerular cells cultured from Trpc6del/del animals, possibly because of disruption of ankyrin repeats 1 and 2. During the chronic phase of PAN nephrosis, Trpc6del/del rats had reduced urine albumin excretion, reduced serum cholesterol and triglycerides, and improved azotemia compared to wild-type Trpc6wt/wt littermates. Glomerulosclerosis was severe during chronic PAN nephrosis in Trpc6wt/wt rats but was markedly reduced in Trpc6del/del littermates. Trpc6del/del animals also had less severe tubulointerstitial fibrosis as assessed by several biochemical and histological analyses, as well as reduced foot process effacement and glomerular basement thickening compared to Trpc6wtt/wt controls. None of the manipulations in this study affected the abundance of TRPC5 channels in renal cortex. TRPC3 was increased in PAN nephrosis and in Trpc6del/del rats. These data support a role for TRPC6 channels in driving an acquired form of secondary FSGS. Key messages We examined aminonucleoside nephrosis in rats with wild type and inactivated TRPC6. TRPC6 channels were inactivated by CRISPR/Cas9 editing of the Trpc6 gene. TRPC6 inactivation reduced albuminuria in the chronic but not the acute phase. TRPC6 inactivation reduced glomerulosclerosis and ultrastructural changes. TRPC6 inactivation also reduced interstitial changes and renal fibrosis.
Electronic supplementary material The online version of this article (10.1007/s00109-018-1648-3) contains supplementary material, which is available to authorized users.
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41
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Immunology of idiopathic nephrotic syndrome. Pediatr Nephrol 2018; 33:573-584. [PMID: 28451893 DOI: 10.1007/s00467-017-3677-5] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 04/05/2017] [Accepted: 04/07/2017] [Indexed: 12/18/2022]
Abstract
The pathogenesis of idiopathic nephrotic syndrome (INS) is as yet unknown, but several lines of evidence indicate that the immune system may play a crucial pathogenic role in non-genetic INS. The most important of these are, first, the effectiveness of therapy based on immunosuppression and, second, a vast body of data derived both from experimental models and from patient studies that implicate T cells and more recently B cells as major players in INS pathogenesis. However, recent findings also suggest a direct role of podocytes as drivers of the disease process, and the interplay between the glomerulus and the immune system is still being elucidated. In this review we provide an overview of current knowledge on the role of different components of the immune system in determining disease. Advances in our understanding of the pathogenesis of INS may help drive new, more tailored therapeutic approaches.
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42
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Dorval G, Gribouval O, Martinez-Barquero V, Machuca E, Tête MJ, Baudouin V, Benoit S, Chabchoub I, Champion G, Chauveau D, Chehade H, Chouchane C, Cloarec S, Cochat P, Dahan K, Dantal J, Delmas Y, Deschênes G, Dolhem P, Durand D, Ekinci Z, El Karoui K, Fischbach M, Grunfeld JP, Guigonis V, Hachicha M, Hogan J, Hourmant M, Hummel A, Kamar N, Krummel T, Lacombe D, Llanas B, Mesnard L, Mohsin N, Niaudet P, Nivet H, Parvex P, Pietrement C, de Pontual L, Noble CP, Ribes D, Ronco P, Rondeau E, Sallee M, Tsimaratos M, Ulinski T, Salomon R, Antignac C, Boyer O. Clinical and genetic heterogeneity in familial steroid-sensitive nephrotic syndrome. Pediatr Nephrol 2018; 33:473-483. [PMID: 29058154 DOI: 10.1007/s00467-017-3819-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Revised: 09/05/2017] [Accepted: 09/07/2017] [Indexed: 10/18/2022]
Abstract
BACKGROUND Familial steroid-sensitive nephrotic syndrome (SSNS) is a rare condition. The disease pathophysiology remains elusive. However, bi-allelic mutations in the EMP2 gene were identified, and specific variations in HLA-DQA1 were linked to a high risk of developing the disease. METHODS Clinical data were analyzed in 59 SSNS families. EMP2 gene was sequenced in families with a potential autosomal recessive (AR) inheritance. Exome sequencing was performed in a subset of 13 families with potential AR inheritance. Two variations in HLA-DQA1 were genotyped in the whole cohort. RESULTS Transmission was compatible with an AR (n = 33) or autosomal dominant (AD, n = 26) inheritance, assuming that familial SSNS is a monogenic trait. Clinical features did not differ between AR and AD groups. All patients, including primary (n = 7) and secondary steroid resistant nephrotic syndrone (SRNS), (n = 13) were sensitive to additional immunosuppressive therapy. Both HLA-DQA1 variations were found to be highly linked to the disease (OR = 4.34 and OR = 4.89; p < 0.001). Exome sequencing did not reveal any pathogenic mutation, neither did EMP2 sequencing. CONCLUSIONS Taken together, these results highlight the clinical and genetic heterogeneity in familial SSNS. Clinical findings sustain an immune origin in all patients, whatever the initial steroid-sensitivity. The absence of a variant shared by two families and the HLA-DQA1 variation enrichments suggest a complex mode of inheritance.
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Affiliation(s)
- Guillaume Dorval
- INSERM UMR1163, Laboratory of Hereditary Kidney Diseases, Imagine Institute, 24 Boulevard du Montparnasse, 75015, Paris, France. .,Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Paris, France.
| | - Olivier Gribouval
- INSERM UMR1163, Laboratory of Hereditary Kidney Diseases, Imagine Institute, 24 Boulevard du Montparnasse, 75015, Paris, France.,Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Paris, France
| | - Vanesa Martinez-Barquero
- INSERM UMR1163, Laboratory of Hereditary Kidney Diseases, Imagine Institute, 24 Boulevard du Montparnasse, 75015, Paris, France.,Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Paris, France
| | - Eduardo Machuca
- INSERM UMR1163, Laboratory of Hereditary Kidney Diseases, Imagine Institute, 24 Boulevard du Montparnasse, 75015, Paris, France
| | - Marie-Josèphe Tête
- INSERM UMR1163, Laboratory of Hereditary Kidney Diseases, Imagine Institute, 24 Boulevard du Montparnasse, 75015, Paris, France.,Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Paris, France
| | - Véronique Baudouin
- Department of Pediatric Nephrology, Assistance Publique-Hôpitaux de Paris, Robert Debré Hospital, Paris, France
| | - Stéphane Benoit
- Department of Nephrology, University Hospital of Tours, Tours, France
| | - Imen Chabchoub
- Department of Pediatrics, Sfax University, Sfax, Tunisia
| | - Gérard Champion
- Department of Pediatrics, University Hospital of Angers, Angers, France
| | - Dominique Chauveau
- Department of Nephrology and Organ Transplantation, University Hospital Rangueil, Toulouse, France
| | - Hassib Chehade
- Department of Pediatrics, Division of Pediatric Nephrology, Lausanne University Hospital, Lausanne, Switzerland
| | - Chokri Chouchane
- Department of Pediatrics, Monastir University, Monastir, Tunisia
| | - Sylvie Cloarec
- Department of Nephrology, University Hospital of Tours, Tours, France
| | - Pierre Cochat
- Department of Pediatric Nephrology, Claude-Bernard Lyon 1 University, Bron, France
| | - Karin Dahan
- Department of Human Genetics, Institute of Pathology and Genetics, Gosselies, Belgium
| | - Jacques Dantal
- Nephrology and Immunology Department, University Hospital of Nantes, Nantes, France
| | - Yahsou Delmas
- Department of Nephrology, University Hospital of Bordeaux, Bordeaux, France
| | - Georges Deschênes
- Department of Pediatric Nephrology, Assistance Publique-Hôpitaux de Paris, Robert Debré Hospital, Paris, France
| | - Phillippe Dolhem
- Department of Pediatrics, Saint-Quentin Hospital, Saint-Quentin, France
| | - Dominique Durand
- Department of Nephrology and Organ Transplantation, University Hospital Rangueil, Toulouse, France
| | | | - Khalil El Karoui
- Department of Nephrology, Assistance Publique-Hôpitaux de Paris, Necker-Enfants Malades Hospital, Paris, France
| | - Michel Fischbach
- Nephrology Dialysis Transplantation Children's Unit, University Hospital Hautepierre, Strasbourg, France
| | - Jean-Pierre Grunfeld
- Department of Nephrology, Assistance Publique-Hôpitaux de Paris, Necker-Enfants Malades Hospital, Paris, France
| | - Vincent Guigonis
- Department of Pediatrics, University Hospital of Limoges, Limoges, France
| | | | - Julien Hogan
- Department of Pediatric Nephrology, Assistance Publique-Hôpitaux de Paris, Armand Trousseau Hospital, Paris, France
| | - Maryvonne Hourmant
- Nephrology and Immunology Department, University Hospital of Nantes, Nantes, France
| | - Aurélie Hummel
- Department of Nephrology, Assistance Publique-Hôpitaux de Paris, Necker-Enfants Malades Hospital, Paris, France
| | - Nassim Kamar
- Department of Nephrology and Organ Transplantation, University Hospital Rangueil, Toulouse, France
| | - Thierry Krummel
- Department of Nephrology, University Hospital Hautepierre, Strasbourg, France
| | - Didier Lacombe
- Department of Genetics, University Hospital of Bordeaux, Bordeaux, France
| | - Brigitte Llanas
- Department of Pediatrics, University Hospital of Bordeaux, Bordeaux, France
| | - Laurent Mesnard
- Department of Nephrology and Dialysis, Assistance Publique-Hôpitaux de Paris, Tenon Hospital, Paris, France.,Sorbonne University, UPMC University Paris 06, Paris, France.,INSERM, UMR_S 1155, 75020, Paris, France
| | - Nabil Mohsin
- College of Medicine, Sultan Qaboos University, Muscat, Oman
| | - Patrick Niaudet
- Department of Pediatric Nephrology, Centre de référence du syndrome néphrotique idiopathique de l'enfant et l'adulte, Assistance Publique-Hôpitaux de Paris, Necker-Enfants Malades Hospital, Paris, France.,Centre de Référence Syndrome Néphrotique Idiopathique de l'enfant et de l'adulte, Paris, France
| | - Hubert Nivet
- Department of Nephrology, University Hospital of Tours, Tours, France
| | - Paloma Parvex
- Department of Pediatrics, Division of Pediatric Nephrology, Geneva University Hospital, Geneva, Switzerland
| | - Christine Pietrement
- Departement of Pediatrics, Nephrology Unit, University Hospital of Reims, Reims, France.,Faculty of Medicine, Laboratory of Biochemistry and Molecular Biology, UMR, CNRS/URCA n°7369, University of Champagne-Ardenne, Reims, France
| | - Loic de Pontual
- Department of Pediatrics, Assistance Publique-Hôpitaux de Paris, Jean Verdier Hospital, Bondy, France
| | - Claire Pouteil Noble
- Department of Nephrology and Transplantation, University Hospital of Lyon, Lyon, France
| | - David Ribes
- Department of Nephrology and Organ Transplantation, University Hospital Rangueil, Toulouse, France
| | - Pierre Ronco
- Department of Nephrology and Dialysis, Assistance Publique-Hôpitaux de Paris, Tenon Hospital, Paris, France.,Sorbonne University, UPMC University Paris 06, Paris, France.,INSERM, UMR_S 1155, 75020, Paris, France
| | - Eric Rondeau
- Department of Nephrology and Dialysis, Assistance Publique-Hôpitaux de Paris, Tenon Hospital, Paris, France
| | - Marion Sallee
- Department of Nephrology and Kidney Transplantation, The Conception Hospital, Marseille, France
| | - Michel Tsimaratos
- Department of Multidisciplinary Pediatrics Timone, Assistance Publique Hôpitaux de Marseille, Aix-Marseille University, Marseille, France
| | - Tim Ulinski
- Department of Pediatric Nephrology, Assistance Publique-Hôpitaux de Paris, Armand Trousseau Hospital, Paris, France
| | - Rémi Salomon
- INSERM UMR1163, Laboratory of Hereditary Kidney Diseases, Imagine Institute, 24 Boulevard du Montparnasse, 75015, Paris, France.,Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Paris, France.,Department of Pediatric Nephrology, Centre de référence du syndrome néphrotique idiopathique de l'enfant et l'adulte, Assistance Publique-Hôpitaux de Paris, Necker-Enfants Malades Hospital, Paris, France.,Centre de Référence Syndrome Néphrotique Idiopathique de l'enfant et de l'adulte, Paris, France
| | - Corinne Antignac
- INSERM UMR1163, Laboratory of Hereditary Kidney Diseases, Imagine Institute, 24 Boulevard du Montparnasse, 75015, Paris, France.,Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Paris, France.,Centre de Référence Syndrome Néphrotique Idiopathique de l'enfant et de l'adulte, Paris, France.,Department of Genetics, Assistance Publique-Hôpitaux de Paris, Necker-Enfants malades Hospital, Paris, France
| | - Olivia Boyer
- INSERM UMR1163, Laboratory of Hereditary Kidney Diseases, Imagine Institute, 24 Boulevard du Montparnasse, 75015, Paris, France.,Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Paris, France.,Department of Pediatric Nephrology, Centre de référence du syndrome néphrotique idiopathique de l'enfant et l'adulte, Assistance Publique-Hôpitaux de Paris, Necker-Enfants Malades Hospital, Paris, France.,Centre de Référence Syndrome Néphrotique Idiopathique de l'enfant et de l'adulte, Paris, France
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Doublier S, Zennaro C, Musante L, Spatola T, Candiano G, Bruschi M, Besso L, Cedrino M, Carraro M, Ghiggeri GM, Camussi G, Lupia E. Soluble CD40 ligand directly alters glomerular permeability and may act as a circulating permeability factor in FSGS. PLoS One 2017; 12:e0188045. [PMID: 29155846 PMCID: PMC5695800 DOI: 10.1371/journal.pone.0188045] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 10/31/2017] [Indexed: 12/17/2022] Open
Abstract
CD40/CD40 ligand (CD40L) dyad, a co-stimulatory bi-molecular complex involved in the adaptive immune response, has also potent pro-inflammatory actions in haematopoietic and non-haematopoietic cells. We describe here a novel role for soluble CD40L (sCD40L) as modifier of glomerular permselectivity directly acting on glomerular epithelial cells (GECs). We found that stimulation of CD40, constitutively expressed on GEC cell membrane, by the sCD40L rapidly induced redistribution and loss of nephrin in GECs, and increased albumin permeability in isolated rat glomeruli. Pre-treatment with inhibitors of CD40-CD40L interaction completely prevented these effects. Furthermore, in vivo injection of sCD40L induced a significant reduction of nephrin and podocin expression in mouse glomeruli, although no significant increase of urine protein/creatinine ratio was observed after in vivo injection. The same effects were induced by plasma factors partially purified from post-transplant plasma exchange eluates of patients with focal segmental glomerulosclerosis (FSGS), and were blocked by CD40-CD40L inhibitors. Moreover, 17 and 34 kDa sCD40L isoforms were detected in the same plasmapheresis eluates by Western blotting. Finally, the levels of sCD40Lwere significantly increased in serum of children both with steroid-sensitive and steroid-resistant nephrotic syndrome (NS), and in adult patients with biopsy-proven FSGS, compared to healthy subjects, but neither in children with congenital NS nor in patients with membranous nephropathy. Our results demonstrate that sCD40L directly modifies nephrin and podocin distribution in GECs. Moreover, they suggest that sCD40L contained in plasmapheresis eluates from FSGS patients with post-transplant recurrence may contribute, presumably cooperating with other mediators, to FSGS pathogenesis by modulating glomerular permeability.
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Affiliation(s)
- Sophie Doublier
- Department of Oncology, University of Turin, Turin, Italy
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Cristina Zennaro
- Department of Medical, Surgery and Health Sciences, University of Trieste, Trieste, Italy
| | - Luca Musante
- Nephrology, Dialysis, Transplantation and Laboratory on Pathophysiology of Uremia, G. Gaslini Children Hospital, Genoa, Italy
| | - Tiziana Spatola
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Giovanni Candiano
- Nephrology, Dialysis, Transplantation and Laboratory on Pathophysiology of Uremia, G. Gaslini Children Hospital, Genoa, Italy
| | - Maurizio Bruschi
- Nephrology, Dialysis, Transplantation and Laboratory on Pathophysiology of Uremia, G. Gaslini Children Hospital, Genoa, Italy
| | - Luca Besso
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Massimo Cedrino
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Michele Carraro
- Department of Medical, Surgery and Health Sciences, University of Trieste, Trieste, Italy
| | - Gian Marco Ghiggeri
- Nephrology, Dialysis, Transplantation and Laboratory on Pathophysiology of Uremia, G. Gaslini Children Hospital, Genoa, Italy
| | - Giovanni Camussi
- Department of Medical Sciences, University of Turin, Turin, Italy
- * E-mail: (EL); (GC)
| | - Enrico Lupia
- Department of Medical Sciences, University of Turin, Turin, Italy
- * E-mail: (EL); (GC)
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44
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Jiang X, Shen W, Xu X, Shen X, Li Y, He Q. Immunosuppressive therapy for steroid-resistant nephrotic syndrome: a Bayesian network meta-analysis of randomized controlled studies. Clin Exp Nephrol 2017; 22:562-569. [PMID: 29080118 DOI: 10.1007/s10157-017-1484-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 09/04/2017] [Indexed: 11/28/2022]
Abstract
BACKGROUND The purpose of this study was to conduct a meta-analysis examining the efficacy of cyclophosphamide, cyclosporin, and tacrolimus in treating steroid resistant nephrotic syndrome. METHODS Medline, Cochrane, EMBASE, and Google Scholar were searched until May 02, 2017 using the keywords: immunosuppressive therapy, steroid-resistant nephrotic syndrome, cyclophosphamide, cyclosporine A, and tacrolimus. Inclusion criteria were randomized controlled trials (RCTs) including patients with SRNS treated with an immunosuppressive therapy or placebo. RESULTS Seven RCTs were included, and the number of patients ranged from 30 to 131. Conventional pair-wise meta-analysis indicated a higher odds of complete or partial remission with tacrolimus as compared to cyclophosphamide [odds ratio (OR) 4.908, 95% confidence interval (CI) 2.278-10.576, P < 0.001], and cyclophosphamide (OR 0.143, 95% CI 0.028-0.721, P = 0.019) and placebo (OR 0.043, 95% CI 0.012-0.157, P < 0.001) were associated with a lower likelihood of complete or partial remission than cyclosporine. Bayesian analysis indicated that tacrolimus and cyclosporine were the best and the second-best agents for inducing a complete or partial remission (rank probability = 0.53 for tacrolimus and 0.46 for cyclosporine). CONCLUSION As compared to cyclophosphamide and cyclosporin, tacrolimus is more effective at inducing remission in patients with SRNS.
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Affiliation(s)
- Xinxin Jiang
- Department of Nephrology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, 158 Shangtang Road, Xiachen District, Hangzhou, 310014, Zhejiang, People's Republic of China
| | - Wei Shen
- Department of Nephrology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, 158 Shangtang Road, Xiachen District, Hangzhou, 310014, Zhejiang, People's Republic of China
| | - Xiujun Xu
- Department of Nephrology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, 158 Shangtang Road, Xiachen District, Hangzhou, 310014, Zhejiang, People's Republic of China
| | - Xiaogang Shen
- Department of Nephrology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, 158 Shangtang Road, Xiachen District, Hangzhou, 310014, Zhejiang, People's Republic of China
| | - Yiwen Li
- Department of Nephrology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, 158 Shangtang Road, Xiachen District, Hangzhou, 310014, Zhejiang, People's Republic of China
| | - Qiang He
- Department of Nephrology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, 158 Shangtang Road, Xiachen District, Hangzhou, 310014, Zhejiang, People's Republic of China.
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45
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A randomized clinical trial indicates that levamisole increases the time to relapse in children with steroid-sensitive idiopathic nephrotic syndrome. Kidney Int 2017; 93:510-518. [PMID: 29054532 DOI: 10.1016/j.kint.2017.08.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 07/25/2017] [Accepted: 08/10/2017] [Indexed: 11/23/2022]
Abstract
Levamisole has been considered the least toxic and least expensive steroid-sparing drug for preventing relapses of steroid-sensitive idiopathic nephrotic syndrome (SSINS). However, evidence for this is limited as previous randomized clinical trials were found to have methodological limitations. Therefore, we conducted an international multicenter, placebo-controlled, double-blind, randomized clinical trial to reassess its usefulness in prevention of relapses in children with SSINS. The efficacy and safety of one year of levamisole treatment in children with SSINS and frequent relapses were evaluated. The primary analysis cohort consisted of 99 patients from 6 countries. Between 100 days and 12 months after the start of study medication, the time to relapse (primary endpoint) was significantly increased in the levamisole compared to the placebo group (hazard ratio 0.22 [95% confidence interval 0.11-0.43]). Significantly, after 12 months of treatment, six percent of placebo patients versus 26 percent of levamisole patients were still in remission. During this period, the most frequent serious adverse event (four of 50 patients) possibly related to levamisole was asymptomatic moderate neutropenia, which was reversible spontaneously or after treatment discontinuation. Thus, in children with SSINS and frequent relapses, levamisole prolonged the time to relapse and also prevented recurrence during one year of treatment compared to prednisone alone. However, regular blood controls are necessary for safety issues.
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46
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Kim EY, Roshanravan H, Dryer SE. Changes in podocyte TRPC channels evoked by plasma and sera from patients with recurrent FSGS and by putative glomerular permeability factors. Biochim Biophys Acta Mol Basis Dis 2017; 1863:2342-2354. [PMID: 28629718 PMCID: PMC5557291 DOI: 10.1016/j.bbadis.2017.06.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 06/13/2017] [Accepted: 06/15/2017] [Indexed: 12/13/2022]
Abstract
Primary forms of focal and segmental glomerulosclerosis (FSGS) are driven by circulating factors that cause dysfunction or loss podocytes. Rare genetic forms of FSGS can be caused by mutations in TRPC6, which encodes a Ca2+-permeable cationic channel expressed in mesangial cells and podocytes; and NPHS2, which encodes podocin, a TRPC6-binding protein expressed in podocyte slit diaphragm domains. Here we observed that exposing immortalized mouse podocytes to serum or plasma from recurrent FSGS patients for 24h increased the steady-state cell-surface abundance of TRPC6, accompanied by an increase in currents through endogenous TRPC6 channels evoked by a hypoosmotic stretch stimulus. These effects were mimicked by the soluble urokinase receptor (suPAR) and by tumor necrosis factor (TNF), circulating factors implicated in nephrotic syndromes. Most but not all of the recurrent FSGS plasma samples that we examined also caused a loss of podocin over a period of several hours. The loss of podocin was also seen following exposure to suPAR but not TNF. However, TNF increased the effects of suPAR on TRPC6 and podocin, and TNF and suPAR are required for the full effects of one of the recurrent FSGS plasma samples. The actions of FSGS plasma, suPAR and TNF on surface abundance of TRPC6 were blocked by cilengitide, an inhibitor of αvβ3-integrin signaling. These data suggest that primary FSGS is a heterogeneous condition mediated by multiple circulating factors, and support TRPC6 and αvβ3-integrin as potential therapeutic targets.
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Affiliation(s)
- Eun Young Kim
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Hila Roshanravan
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Stuart E Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA; Department of Medicine, Division of Nephrology, Baylor College of Medicine, Houston, TX, USA.
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Karp AM, Gbadegesin RA. Genetics of childhood steroid-sensitive nephrotic syndrome. Pediatr Nephrol 2017; 32:1481-1488. [PMID: 27470160 PMCID: PMC5276801 DOI: 10.1007/s00467-016-3456-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 06/27/2016] [Accepted: 06/29/2016] [Indexed: 02/07/2023]
Abstract
The pathogenesis of childhood-onset nephrotic syndrome (NS), disparity in incidence of NS among races, and variable responses to therapies in children with NS have defied explanation to date. In the last 20 years over 50 genetic causes of steroid-resistant nephrotic syndrome (SRNS) have been identified, and at least two disease loci for two pathologic variants of SRNS (focal segmental glomerulosclerosis and membranous nephropathy) have been defined. However, the genetic causes and risk loci for steroid-sensitive nephrotic syndrome (SSNS) remain elusive, partly because SSNS is relatively rare and also because cases of SSNS vary widely in phenotypic expression over time. A recent study of a well-defined modest cohort of children with SSNS identified variants in HLA-DQA1 as a risk factor for SSNS. Here we review what is currently known about the genetics of SSNS and also discuss how recent careful phenotypic and genomic studies reinforce the role of adaptive immunity in the molecular mechanisms of SSNS.
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Affiliation(s)
- Alana M. Karp
- Department of Pediatrics, Division of Nephrology, Emory University, Atlanta, GA, USA
| | - Rasheed A. Gbadegesin
- Department of Pediatrics, Division of Nephrology, Duke University Medical Center, Durham, NC,Duke Molecular Physiology Institute, Duke University, Durham, NC,To whom correspondence should be addressed:
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48
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Peruzzi L, Albiani R, Giancaspero K. Plasma exchange in kidney transplantation: Still a valuable option for nephrotic syndrome recurrence. Transfus Apher Sci 2017; 56:525-530. [PMID: 28830667 DOI: 10.1016/j.transci.2017.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
About 30% of the cases of steroid resistant nephrotic syndrome display a genetically determined disease and will not recur after kidney transplant; the other cases with fully or partially immunological pathogenesis display a high risk of post transplant recurrence. Although lots of studies were carried out in the last 50 years the pathogenetic mechanism is still obscure and the therapeutic approach mostly empirical. The cornerstones principles of the therapies are based on removal of a still undefined "permeability factor" through plasma-exchange or other apheresis techniques and inhibition of its synthesis by the immunological system through different drugs. The probability of successfully inducing persistant remission is nowadays around 30%through the different schemes experimented so far which mostly include plasmapheresis. Rituximab in the last years has significantly increased the efficacy of the treatments. Non responders are rapidly evolving to graft loss and will most probably recur also in subsequent transplant. Apart from genetics no other risk factors are predictive for recurrence.
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Affiliation(s)
- Licia Peruzzi
- Pediatric Nephrology Unit, Regina Margherita Children's Hospital, Città della Salute e della Scienza di Torino, Turin, Italy.
| | - Roberto Albiani
- Apheresis Unit, Regina Margherita Children's Hospital, Città della Salute e della Scienza di Torino, Turin, Italy
| | - Karol Giancaspero
- Apheresis Unit, Regina Margherita Children's Hospital, Città della Salute e della Scienza di Torino, Turin, Italy
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49
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Role of gut microbiota in idiopathic nephrotic syndrome in children. Med Hypotheses 2017; 108:35-37. [PMID: 29055396 DOI: 10.1016/j.mehy.2017.07.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 07/31/2017] [Indexed: 12/20/2022]
Abstract
Nephrotic syndrome characterized by heavy proteinuria and edema is the most common chronic kidney disease in children. It is classified into three categories, of which the idiopathic type accounts for the vast majority of cases. As indicated by the name, the etiology of idiopathic nephrotic syndrome remains unknown though it has been suggested that impaired T cell function is involved. Recently, evidence has mounted to suggest that dysfunction in regulatory T cells plays an important role in the development of allergic disease, a recognized comorbid condition for children with idiopathic nephrotic syndrome. It is known that regulatory T cells are mainly induced by short chain fatty acids produced by gut microbiota and that children with allergy are reported to have aberrant gut microbiota. On this basis, we hypothesize that an aberrant microbiota, i.e., dysbiosis in the gut resulting in defective induction of regulatory T cells, is also involved in the etiology of idiopathic nephrotic syndrome in children. Our hypothesis can be directly tested by metagenome analysis using bacterial DNA extracted from the feces of patients with idiopathic nephrotic syndrome. Indirect evidence could be obtained by epidemiological survey, such as a comparative study of the environmental factors influencing the initial colonization of gut microbiota between patients with idiopathic nephrotic syndrome and age-matched healthy children. Factors that may disrupt this colonization include a cesarean delivery, formula feeding, excessive use of antibiotics, or the introduction of inappropriate solid foods containing a high amount of saturated fat. Based on this hypothesis, we suggest it would be clinically worthwhile to study whether administration of probiotics composed of commensal bacteria known to efficiently induce regulatory T cells in vitro could control the exacerbation or relapse of INS.
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50
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Müller-Deile J, Schiffer M. Podocytes from the diagnostic and therapeutic point of view. Pflugers Arch 2017; 469:1007-1015. [PMID: 28508947 DOI: 10.1007/s00424-017-1993-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 05/04/2017] [Indexed: 01/23/2023]
Abstract
The central role of podocytes in glomerular diseases makes this cell type an interesting diagnostic tool as well as a therapeutic target. In this review, we discuss the current literature on the use of podocytes and podocyte-specific markers as non-invasive diagnostic tools in different glomerulopathies. Furthermore, we highlight the direct effects of drugs currently used to treat primary glomerular diseases and describe their direct cellular effects on podocytes. A new therapeutic potential is seen in drugs targeting the podocytic actin cytoskeleton which is essential for podocyte foot process structure and function. Incubation of cultured human podocyte cell lines with sera from patients with active glomerular diseases is currently also used to identify novel circulating factors with pathophysiological relevance for the glomerular filtration barrier. In addition, treatment of detached urinary podocytes from patients with substances that restore their cytoskeleton might serve as a novel personalized tool to estimate their potential for podocyte recovery ex vivo.
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Affiliation(s)
- Janina Müller-Deile
- Department of Nephrology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| | - Mario Schiffer
- Department of Nephrology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
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