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Bezdicka M, Cinek O, Semjonov V, Polackova K, Sladkova E, Zieg J, Saleem MA, Soucek O. Nephrotic syndrome sera induce different transcriptomes in podocytes based on the steroid response. Physiol Rep 2024; 12:e15932. [PMID: 38307723 PMCID: PMC10837055 DOI: 10.14814/phy2.15932] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 12/14/2023] [Accepted: 01/01/2024] [Indexed: 02/04/2024] Open
Abstract
As the molecular mechanism of nephrotic syndrome remains largely undiscovered, patients continue to be exposed to the pros and cons of uniform glucocorticoid treatment. We explored whether the exposure of in vitro-cultivated podocytes to sera from children with steroid-sensitive or steroid-resistant nephrotic syndrome induces differences in gene expression profiles, which could help to elucidate the pathogenesis of the steroid response. Human immortalized podocytes were cultivated with patient sera for 3 days. After cell lysis, RNA extraction, 3'-mRNA libraries were prepared and sequenced. There were 34 significantly upregulated and 14 downregulated genes (fold difference <0.5 and >2.0, respectively, and false discovery rate-corrected p < 0.05) and 22 significantly upregulated and 6 downregulated pathways (false discovery rate-corrected p < 0.01) in the steroid-sensitive (n = 9) versus steroid-resistant group (n = 4). The observed pathways included upregulated redox reactions, DNA repair, mitosis, protein translation and downregulated cholesterol biosynthesis. Sera from children with nephrotic syndrome induce disease subtype-specific transcriptome changes in human podocytes in vitro. However, further exploration of a larger cohort is needed to verify whether clinically distinct types of nephrotic syndrome or disease activity may be differentiated by specific transcriptomic profiles and whether this information may help to elucidate the pathogenesis of the steroid response.
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Affiliation(s)
- Martin Bezdicka
- Vera Vavrova Lab/VIAL, Department of Pediatrics, Second Faculty of MedicineCharles University and Motol University HospitalPragueCzech Republic
| | - Ondrej Cinek
- Department of Pediatrics, Second Faculty of MedicineCharles University and Motol University HospitalPragueCzech Republic
| | - Valerij Semjonov
- Department of Pediatrics, Second Faculty of MedicineCharles University and Motol University HospitalPragueCzech Republic
| | - Katerina Polackova
- Vera Vavrova Lab/VIAL, Department of Pediatrics, Second Faculty of MedicineCharles University and Motol University HospitalPragueCzech Republic
| | - Eva Sladkova
- Children's Clinic, Faculty of Medicine in PilsenUniversity Hospital in Pilsen, Charles UniversityPilsenCzech Republic
| | - Jakub Zieg
- Department of Pediatrics, Second Faculty of MedicineCharles University and Motol University HospitalPragueCzech Republic
| | - Moin A. Saleem
- Bristol Renal and Bristol Royal Hospital for ChildrenUniversity of Bristol Medical SchoolBristolUK
| | - Ondrej Soucek
- Vera Vavrova Lab/VIAL, Department of Pediatrics, Second Faculty of MedicineCharles University and Motol University HospitalPragueCzech Republic
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2
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Hayward S, Parmesar K, Saleem MA. What is circulating factor disease and how is it currently explained? Pediatr Nephrol 2023; 38:3513-3518. [PMID: 36952039 PMCID: PMC10514121 DOI: 10.1007/s00467-023-05928-8] [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: 01/13/2023] [Revised: 02/15/2023] [Accepted: 02/20/2023] [Indexed: 03/24/2023]
Abstract
Nephrotic syndrome (NS) consists of the clinical triad of hypoalbuminaemia, high levels of proteinuria and oedema, and describes a heterogeneous group of disease processes with different underlying drivers. The existence of circulating factor disease (CFD) as a driver of NS has been epitomised by a subset of patients who exhibit disease recurrence after transplantation, alongside laboratory work. Several circulating factors have been proposed and studied, broadly grouped into protease components such as soluble urokinase-type plasminogen activator (suPAR), hemopexin (Hx) and calcium/calmodulin-serine protease kinase (CASK), and other circulating proteases, and immune components such as TNF-α, CD40 and cardiotrophin-like cytokine-1 (CLC-1). While currently there is no definitive way of assessing risk of CFD pre-transplantation, promising work is emerging through the study of 'multi-omic' bioinformatic data from large national cohorts and biobanks.
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Affiliation(s)
- Samantha Hayward
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.
- MRC Integrative Epidemiology Unit, Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.
| | - Kevon Parmesar
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Moin A Saleem
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
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3
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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: 5] [Impact Index Per Article: 5.0] [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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5
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Vinogradov AA, Chebotareva NV, Bugrova AE, Brzhozovskiy AG, Krasnova TN, Nasibullina KZ, Kononikhin AS, Moiseev SV. [Study of urinary markers of different podocytopathies by proteomic analysis]. TERAPEVT ARKH 2023; 95:457-461. [PMID: 38158963 DOI: 10.26442/00403660.2023.06.202266] [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: 08/14/2023] [Accepted: 08/14/2023] [Indexed: 01/03/2024]
Abstract
BACKGROUND Focal segmental glomerulosclerosis (FSGS) is a primary podocytopathy characterized by primary podocyte detection and high proteinuria. The search for biomarkers and factors associated with the progression of this disease is an important task nowdays. AIM To assess the proteomic profile of urine in patients with FSGS and to isolate urinary biomarkers of podocytopathies. MATERIALS AND METHODS The study included 41 patients diagnosed with chronic glomerulonephritis, 27 men and 14 women. According to the morphological study, 28 patients were diagnosed with FSGS, 9 with steroid-sensitive nephrotic syndrome and 14 with steroid-resistant nephrotic syndrome. The comparison group included 13 patients with membranous nephropathy. The study of the urinary proteome was carried out by targeted liquid chromatography-mass spectrometry using multiple reaction monitoring with synthetic stable isotope labelled peptide standards. RESULTS The main differences in the protein profile of urine were found in the subgroups of steroid-sensitive (SS) and steroid-resistant (SR) FSGS. In the FSGS SR group, at the onset of the disease, there was a high concentration of proteins reflecting damage to the glomerular filter (apo-lipoprotein A-IV, orosomucoid, cadherin, hemopexin, vitronectin), as well as proteins associated with tubulo-interstitial inflammation and accumulation of extracellular matrix (retinol- and vitamin D-binding proteins, kininogen-1, lumican and neurophilin-2). Compared with the membranous nephropathy group, FSGS patients had significantly higher urinary concentrations of carnosinase, orosomucoid, cadherin-13, tenascin X, osteopontin, and zinc-alpha-2-glycoprotein. CONCLUSION Thus, in patients with SR FSGS, the proteomic profile of urine includes more proteins at elevated concentrations, which reflects severe damage to various parts of the nephron compared with patients with SS FSGS and membranous nephropathy.
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Affiliation(s)
| | - N V Chebotareva
- Sechenov First Moscow State Medical University (Sechenov University)
| | | | | | - T N Krasnova
- Lomonosov Moscow State University
- Sechenov First Moscow State Medical University (Sechenov University)
| | - K Z Nasibullina
- Sechenov First Moscow State Medical University (Sechenov University)
| | | | - S V Moiseev
- Sechenov First Moscow State Medical University (Sechenov University)
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6
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Vincenti F, Angeletti A, Ghiggeri GM. State of the art in childhood nephrotic syndrome: concrete discoveries and unmet needs. Front Immunol 2023; 14:1167741. [PMID: 37503337 PMCID: PMC10368981 DOI: 10.3389/fimmu.2023.1167741] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 06/21/2023] [Indexed: 07/29/2023] Open
Abstract
Nephrotic syndrome (NS) is a clinical entity characterized by proteinuria, hypoalbuminemia, and peripheral edema. NS affects about 2-7 per 100,000 children aged below 18 years old yearly and is classified, based on the response to drugs, into steroid sensitive (SSNS), steroid dependent, (SDNS), multidrug dependent (MDNS), and multidrug resistant (MRNS). Forms of NS that are more difficult to treat are associated with a worse outcome with respect to renal function. In particular, MRNS commonly progresses to end stage renal failure requiring renal transplantation, with recurrence of the original disease in half of the cases. Histological presentations of NS may vary from minimal glomerular lesions (MCD) to focal segmental glomerulosclerosis (FSGS) and, of relevance, the histological patterns do not correlate with the response to treatments. Moreover, around half of MRNS cases are secondary to causative pathogenic variants in genes involved in maintaining the glomerular structure. The pathogenesis of NS is still poorly understood and therapeutic approaches are mostly based on clinical experience. Understanding of pathogenetic mechanisms of NS is one of the 'unmet needs' in nephrology and represents a significant challenge for the scientific community. The scope of the present review includes exploring relevant findings, identifying unmet needs, and reviewing therapeutic developments that characterize NS in the last decades. The main aim is to provide a basis for new perspectives and mechanistic studies in NS.
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Affiliation(s)
- Flavio Vincenti
- Division of Nephrology, Department of Medicine and Department of Surgery, University of California San Francisco, San Francisco, CA, United States
| | - Andrea Angeletti
- Nephrology Dialysis and Transplantation, Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS) Istituto Giannina Gaslini, Genoa, Italy
| | - Gian Marco Ghiggeri
- Nephrology Dialysis and Transplantation, Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS) Istituto Giannina Gaslini, Genoa, Italy
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7
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Cook J, Greene ES, Ramser A, Mullenix G, Dridi JS, Liyanage R, Wideman R, Dridi S. Comparative- and network-based proteomic analysis of bacterial chondronecrosis with osteomyelitis lesions in broiler's proximal tibiae identifies new molecular signatures of lameness. Sci Rep 2023; 13:5947. [PMID: 37045932 PMCID: PMC10097873 DOI: 10.1038/s41598-023-33060-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 04/06/2023] [Indexed: 04/14/2023] Open
Abstract
Bacterial Chondronecrosis with Osteomyelitis (BCO) is a specific cause of lameness in commercial fast-growing broiler (meat-type) chickens and represents significant economic, health, and wellbeing burdens. However, the molecular mechanisms underlying the pathogenesis remain poorly understood. This study represents the first comprehensive characterization of the proximal tibia proteome from healthy and BCO chickens. Among a total of 547 proteins identified, 222 were differentially expressed (DE) with 158 up- and 64 down-regulated proteins in tibia of BCO vs. normal chickens. Biological function analysis using Ingenuity Pathways showed that the DE proteins were associated with a variety of diseases including cell death, organismal injury, skeletal and muscular disorder, immunological and inflammatory diseases. Canonical pathway and protein-protein interaction network analysis indicated that these DE proteins were involved in stress response, unfolded protein response, ribosomal protein dysfunction, and actin cytoskeleton signaling. Further, we identified proteins involved in bone resorption (osteoclast-stimulating factor 1, OSFT1) and bone structural integrity (collagen alpha-2 (I) chain, COL2A1), as potential key proteins involved in bone attrition. These results provide new insights by identifying key protein candidates involved in BCO and will have significant impact in understanding BCO pathogenesis.
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Affiliation(s)
- Jennifer Cook
- Department of Poultry Science, University of Arkansas, 1260 W. Maple Street, Fayetteville, AR, 72701, USA
| | - Elizabeth S Greene
- Department of Poultry Science, University of Arkansas, 1260 W. Maple Street, Fayetteville, AR, 72701, USA
| | - Alison Ramser
- Department of Poultry Science, University of Arkansas, 1260 W. Maple Street, Fayetteville, AR, 72701, USA
| | - Garrett Mullenix
- Department of Poultry Science, University of Arkansas, 1260 W. Maple Street, Fayetteville, AR, 72701, USA
| | - Jalila S Dridi
- École Universitaire de Kinésithérapie, Université d'Orléans, Rue de Chartres, 45100, Orléans, France
| | - Rohana Liyanage
- Department of Poultry Science, University of Arkansas, 1260 W. Maple Street, Fayetteville, AR, 72701, USA
| | - Robert Wideman
- Department of Poultry Science, University of Arkansas, 1260 W. Maple Street, Fayetteville, AR, 72701, USA
| | - Sami Dridi
- Department of Poultry Science, University of Arkansas, 1260 W. Maple Street, Fayetteville, AR, 72701, USA.
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Fan X, Zhang X, Liu LC, Zhang S, Pelger CB, Lughmani HY, Haller ST, Gunning WT, Cooper CJ, Gong R, Dworkin LD, Gupta R. Hemopexin accumulates in kidneys and worsens acute kidney injury by causing hemoglobin deposition and exacerbation of iron toxicity in proximal tubules. Kidney Int 2022; 102:1320-1330. [PMID: 36007598 DOI: 10.1016/j.kint.2022.07.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 06/29/2022] [Accepted: 07/11/2022] [Indexed: 01/12/2023]
Abstract
Hemopexin, a heme scavenging protein, accumulates in the kidneys during acute kidney injury (AKI). However, the function of this accumulated hemopexin in the kidney is unclear. In both the cisplatin-induced and the unilateral kidney ischemia-reperfusion injury models of AKI, we found accumulation of hemoglobin and hemopexin in the kidneys localized to the proximal tubules. Next, hemopexin wild-type and knockout mice were compared in both AKI models and hemopexin wild type mice had significantly worse kidney injury. Furthermore, there was increased kidney expression of kidney injury molecule-1 (a biomarker of AKI) and heme oxygenase-1 (an indicator of oxidative stress) in hemopexin wild type compared with knockout mice in both models of AKI. Next, the interaction of hemopexin and hemoglobin in vitro was investigated using cultured proximal tubular cells. Co-incubation of hemopexin with hemoglobin resulted in hemoglobin deposition and exaggerated hemoglobin-induced injury. Deferoxamine, an iron chelator, and ferrostatin-1, a ferroptosis inhibitor, inhibited this deleterious effect of hemoglobin and hemopexin in proximal tubular cells, implicating iron toxicity in the mechanism of hemopexin mediated injury. Furthermore, the protective effect of deferoxamine in cisplatin-induced AKI was apparent in hemopexin wild type, but not in hemopexin knockout mice, further implicating hemopexin as a mediator of iron toxicity in AKI. Thus, our findings demonstrate that hemopexin accumulates in the kidneys and worsens kidney injury in AKI by increasing hemoglobin deposition on proximal tubular cells to exaggerate hemoglobin-induced cell injury.
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Affiliation(s)
- Xiaoming Fan
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio, USA
| | - Xiaolu Zhang
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio, USA
| | - Lijun C Liu
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio, USA
| | - Shungang Zhang
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio, USA
| | - Cole B Pelger
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio, USA
| | - Haroon Y Lughmani
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio, USA
| | - Steven T Haller
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio, USA
| | - William T Gunning
- Department of Pathology, University of Toledo College of Medicine, Toledo, Ohio, USA
| | - Christopher J Cooper
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio, USA
| | - Rujun Gong
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio, USA
| | - Lance D Dworkin
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio, USA
| | - Rajesh Gupta
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio, USA.
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Potential Urine Proteomic Biomarkers for Focal Segmental Glomerulosclerosis and Minimal Change Disease. Int J Mol Sci 2022; 23:ijms232012607. [PMID: 36293475 PMCID: PMC9604469 DOI: 10.3390/ijms232012607] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 09/25/2022] [Accepted: 10/06/2022] [Indexed: 11/23/2022] Open
Abstract
Primary focal segmental glomerulosclerosis (FSGS), along with minimal change disease (MCD), are diseases with primary podocyte damage that are clinically manifested by the nephrotic syndrome. The pathogenesis of these podocytopathies is still unknown, and therefore, the search for biomarkers of these diseases is ongoing. Our aim was to determine of the proteomic profile of urine from patients with FSGS and MCD. Patients with a confirmed diagnosis of FSGS (n = 30) and MCD (n = 9) were recruited for the study. For a comprehensive assessment of the severity of FSGS a special index was introduced, which was calculated as follows: the first score was assigned depending on the level of eGFR, the second score—depending on the proteinuria level, the third score—resistance to steroid therapy. Patients with the sum of these scores of less than 3 were included in group 1, with 3 or more—in group 2. The urinary proteome was analyzed using liquid chromatography/mass spectrometry. The proteome profiles of patients with severe progressive FSGS from group 2, mild FSGS from group 1 and MCD were compared. Results of the label free analysis were validated using targeted LC-MS based on multiple reaction monitoring (MRM) with stable isotope labelled peptide standards (SIS) available for 47 of the 76 proteins identified as differentiating between at least one pair of groups. Quantitative MRM SIS validation measurements for these 47 proteins revealed 22 proteins with significant differences between at least one of the two group pairs and 14 proteins were validated for both comparisons. In addition, all of the 22 proteins validated by MRM SIS analysis showed the same direction of change as at the discovery stage with label-free LC-MS analysis, i.e., up or down regulation in MCD and FSGS1 against FSGS2. Patients from the FSGS group 2 showed a significantly different profile from both FSGS group 1 and MCD. Among the 47 significantly differentiating proteins, the most significant were apolipoprotein A-IV, hemopexin, vitronectin, gelsolin, components of the complement system (C4b, factors B and I), retinol- and vitamin D-binding proteins. Patients with mild form of FSGS and MCD showed lower levels of Cystatin C, gelsolin and complement factor I.
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10
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Bauer C, Piani F, Banks M, Ordoñez FA, de Lucas-Collantes C, Oshima K, Schmidt EP, Zakharevich I, Segarra A, Martinez C, Roncal-Jimenez C, Satchell SC, Bjornstad P, Lucia MS, Blaine J, Thurman JM, Johnson RJ, Cara-Fuentes G. Minimal Change Disease Is Associated With Endothelial Glycocalyx Degradation and Endothelial Activation. Kidney Int Rep 2022; 7:797-809. [PMID: 35497798 PMCID: PMC9039905 DOI: 10.1016/j.ekir.2021.11.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 11/03/2021] [Accepted: 11/29/2021] [Indexed: 01/05/2023] Open
Abstract
Introduction Minimal change disease (MCD) is considered a podocyte disorder triggered by unknown circulating factors. Here, we hypothesized that the endothelial cell (EC) is also involved in MCD. Methods We studied 45 children with idiopathic nephrotic syndrome (44 had steroid sensitive nephrotic syndrome [SSNS], and 12 had biopsy-proven MCD), 21 adults with MCD, and 38 healthy controls (30 children, 8 adults). In circulation, we measured products of endothelial glycocalyx (EG) degradation (syndecan-1, heparan sulfate [HS] fragments), HS proteoglycan cleaving enzymes (matrix metalloprotease-2 [MMP-2], heparanase activity), and markers of endothelial activation (von Willebrand factor [vWF], thrombomodulin) by enzyme-linked immunosorbent assay (ELISA) and mass spectrometry. In human kidney tissue, we assessed glomerular EC (GEnC) activation by immunofluorescence of caveolin-1 (n = 11 MCD, n = 5 controls). In vitro, we cultured immortalized human GEnC with sera from control subjects and patients with MCD/SSNS sera in relapse (n = 5 per group) and performed Western blotting of thrombomodulin of cell lysates as surrogate marker of endothelial activation. Results In circulation, median concentrations of all endothelial markers were higher in patients with active disease compared with controls and remained high in some patients during remission. In the MCD glomerulus, caveolin-1 expression was higher, in an endothelial-specific pattern, compared with controls. In cultured human GEnC, sera from children with MCD/SSNS in relapse increased thrombomodulin expression compared with control sera. Conclusion Our data show that alterations involving the systemic and glomerular endothelium are nearly universal in patients with MCD and SSNS, and that GEnC can be directly activated by circulating factors present in the MCD/SSNS sera during relapse.
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Affiliation(s)
- Colin Bauer
- Section of Pediatric Nephrology, Department of Pediatrics, Children's Hospital Colorado, Aurora, Colorado, USA
| | - Federica Piani
- Section of Pediatric Nephrology, Department of Pediatrics, Children's Hospital Colorado, Aurora, Colorado, USA
- Department of Medicine and Surgery Sciences, Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Mindy Banks
- Division of Pediatric Nephrology, Rocky Mountain Children's Hospital, Denver, Colorado, USA
| | - Flor A Ordoñez
- Division of Pediatric Nephrology, Hospital Universitario Central de Asturias, Oviedo, Spain
| | | | - Kaori Oshima
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Eric P Schmidt
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Igor Zakharevich
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Alfons Segarra
- Department of Nephrology, Hospital Universitario Arnau de Vilanova, Lleida, Spain
- Lleida Institute for Biomedical Research Dr. Pifarré Foundation, Lleida, Spain
- Division of Nephrology, Hospital General Vall d'Hebron, Barcelona, Spain
| | - Cristina Martinez
- Lleida Institute for Biomedical Research Dr. Pifarré Foundation, Lleida, Spain
| | - Carlos Roncal-Jimenez
- Department of Medicine, Division of Renal Diseases and Hypertension, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | | | - Petter Bjornstad
- Department of Medicine, Division of Renal Diseases and Hypertension, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Pediatrics, Section of Pediatric Endocrinology, Children's Hospital Colorado and University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Marshall Scott Lucia
- Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Judith Blaine
- Department of Medicine, Division of Renal Diseases and Hypertension, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Joshua M Thurman
- Department of Medicine, Division of Renal Diseases and Hypertension, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Richard J Johnson
- Department of Medicine, Division of Renal Diseases and Hypertension, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Gabriel Cara-Fuentes
- Section of Pediatric Nephrology, Department of Pediatrics, Children's Hospital Colorado, Aurora, Colorado, USA
- Department of Medicine, Division of Renal Diseases and Hypertension, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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11
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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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12
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Divergent roles of haptoglobin and hemopexin deficiency for disease progression of Shiga-toxin-induced hemolytic-uremic syndrome in mice. Kidney Int 2022; 101:1171-1185. [PMID: 35031328 DOI: 10.1016/j.kint.2021.12.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 12/05/2021] [Accepted: 12/16/2021] [Indexed: 02/06/2023]
Abstract
Thrombotic microangiopathy, hemolysis and acute kidney injury are typical clinical characteristics of hemolytic-uremic syndrome (HUS), which is predominantly caused by Shiga-toxin-producing Escherichia coli. Free heme aggravates organ damage in life-threatening infections, even with a low degree of systemic hemolysis. Therefore, we hypothesized that the presence of the hemoglobin- and the heme-scavenging proteins, haptoglobin and hemopexin, respectively impacts outcome and kidney pathology in HUS. Here, we investigated the effect of haptoglobin and hemopexin deficiency (haptoglobin-/-, hemopexin-/-) and haptoglobin treatment in a murine model of HUS-like disease. Seven-day survival was decreased in haptoglobin-/- (25%) compared to wild type mice (71.4%), whereas all hemopexin-/- mice survived. Shiga-toxin-challenged hemopexin-/- mice showed decreased kidney inflammation and attenuated thrombotic microangiopathy, indicated by reduced neutrophil recruitment and platelet deposition. These observations were associated with supranormal haptoglobin plasma levels in hemopexin-/- mice. Low dose haptoglobin administration to Shiga-toxin-challenged wild type mice attenuated kidney platelet deposition and neutrophil recruitment, suggesting that haptoglobin at least partially contributes to the beneficial effects. Surrogate parameters of hemolysis were elevated in Shiga-toxin-challenged wild type and haptoglobin-/- mice, while signs for hepatic hemoglobin degradation like heme oxygenase-1, ferritin and CD163 expression were only increased in Shiga-toxin-challenged wild type mice. In line with this observation, haptoglobin-/- mice displayed tubular iron deposition as an indicator for kidney hemoglobin degradation. Thus, haptoglobin and hemopexin deficiency play divergent roles in Shiga-toxin-mediated HUS, suggesting haptoglobin is involved, and hemopexin is redundant for the resolution of HUS pathology.
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13
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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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14
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Tamura H. Trends in pediatric nephrotic syndrome. World J Nephrol 2021; 10:88-100. [PMID: 34631479 PMCID: PMC8477269 DOI: 10.5527/wjn.v10.i5.88] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 05/15/2021] [Accepted: 08/10/2021] [Indexed: 02/06/2023] Open
Abstract
Nephrotic syndrome (NS) is relatively common in children, with most of its histological types being minimal changed disease. Its etiology has long been attributed to lymphocyte (especially T-cell) dysfunction, while T-cell-mediated vascular hyperpermeability increases protein permeability in glomerular capillaries, leading to proteinuria and hypoproteinemia. Based on this etiology, steroids and immunosuppressive drugs that are effective against this disease have also been considered to correct T-cell dysfunction. However, in recent years, this has been questioned. The primary cause of NS has been considered damage to glomerular epithelial cells and podocyte-related proteins. Therefore, we first describe the changes in expression of molecules involved in NS etiology, and then describe the mechanism by which abnormal expression of these molecules induces proteinuria. Finally, we consider the mechanism by which infection causes the recurrence of NS.
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Affiliation(s)
- Hiroshi Tamura
- Department of Pediatrics, Kumamoto University, Kumamoto 8608556, Japan
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15
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Detsika MG, Lianos EA. Hemopexin Modulates Expression of Complement Regulatory Proteins in Rat Glomeruli. Curr Issues Mol Biol 2021; 43:1081-1089. [PMID: 34563046 PMCID: PMC8928991 DOI: 10.3390/cimb43020077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/29/2021] [Accepted: 09/02/2021] [Indexed: 11/17/2022] Open
Abstract
In systemic hemolysis and in hematuric forms of kidney injury, the major heme scavenging protein, hemopexin (HPX), becomes depleted, and the glomerular microvasculature (glomeruli) is exposed to high concentrations of unbound heme, which, in addition to causing oxidative injury, can activate complement cascades; thus, compounding extent of injury. It is unknown whether unbound heme can also activate specific complement regulatory proteins that could defend against complement-dependent injury. Isolated rat glomeruli were incubated in media supplemented with HPX-deficient (HPX-) or HPX-containing (HPX+) sera as a means of achieving different degrees of heme partitioning between incubation media and glomerular cells. Expression of heme oxygenase (HO)-1 and of the complement activation inhibitors, decay-accelerating factor (DAF), CD59, and complement receptor-related gene Y (Crry), was assessed by western blot analysis. Expression of HO-1 and of the GPI-anchored DAF and CD59 proteins increased in isolated glomeruli incubated with HPX- sera with no effect on Crry expression. Exogenous heme (hemin) did not further induce DAF but increased Crry expression. HPX modulates heme-mediated induction of complement activation controllers in glomeruli. This effect could be of translational relevance in glomerular injury associated with hematuria.
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Affiliation(s)
- Maria G. Detsika
- 1st Department of Critical Care Medicine and Pulmonary Services, G. P. Livanou and M. Simou Laboratories, School of Medicine, National and Kapodistrian University of Athens, Evangelismos Hospital, 10675 Athens, Greece
| | - Elias A. Lianos
- Veterans Affairs Medical Center and Virginia Tech., Carilion School of Medicine, 1970 Roanoke Blvd, Salem, VA 24153, USA;
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16
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Cara-Fuentes G, Smoyer WE. Biomarkers in pediatric glomerulonephritis and nephrotic syndrome. Pediatr Nephrol 2021; 36:2659-2673. [PMID: 33389089 DOI: 10.1007/s00467-020-04867-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 10/16/2020] [Accepted: 11/18/2020] [Indexed: 12/21/2022]
Abstract
Glomerular diseases are often chronic or recurring and thus associated with a tremendous physical, psychological, and economic burden. Their etiologies are often unknown, and their pathogeneses are frequently poorly understood. The diagnoses and management of these diseases are therefore based on clinical features, traditional laboratory markers, and, often, kidney pathology. However, the clinical presentation can be highly variable, the kidney pathology may not establish a definitive diagnosis, and the therapeutic responses and resulting clinical outcomes are often unpredictable. To try to address these challenges, significant research efforts have been made over the last decade to identify potential biomarkers that can help clinicians optimize the diagnosis and prognosis at clinical presentation, as well as help predict long-term outcomes. Unfortunately, these efforts have to date only identified a single biomarker for glomerular disease that has been fully validated and developed for widespread clinical use (anti-PLA2R antibodies to diagnose membranous nephropathy). In this manuscript, we review the definitions and development of biomarkers, as well as the current knowledge on both historical and novel candidate biomarkers of glomerular disease, with an emphasis on those associated with idiopathic nephrotic syndrome.
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Affiliation(s)
- Gabriel Cara-Fuentes
- Department of Pediatrics, Division of Pediatric Nephrology, University of Colorado, 12700 E 19th Ave, R2 building, Room 7420D, Aurora, CO, 80045, USA.
| | - William E Smoyer
- Center for Clinical and Translational Research, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.,Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, OH, USA
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17
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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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18
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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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19
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MicroRNAs as Biomarkers for Nephrotic Syndrome. Int J Mol Sci 2020; 22:ijms22010088. [PMID: 33374848 PMCID: PMC7795691 DOI: 10.3390/ijms22010088] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 12/19/2020] [Accepted: 12/22/2020] [Indexed: 12/15/2022] Open
Abstract
Nephrotic syndrome represents the clinical situation characterized by presence of massive proteinuria and low serum protein caused by a variety of diseases, including minimal change nephrotic syndrome (MCNS), focal segmental glomerulosclerosis (FSGS) and membranous glomerulonephropathy. Differentiating between diagnoses requires invasive renal biopsies in general. Even with the biopsy, we encounter difficulties to differentiate MCNS and FSGS in some cases. There is no other better option currently available for the diagnosis other than renal biopsy. MicroRNAs (miRNAs) are no-coding RNAs of approximately 20 nucleotides in length, which regulate target genes in the post-transcriptional processes and have essential roles in many diseases. MiRNAs in serum and urine have been shown as non-invasive biomarkers in multiple diseases, including renal diseases. In this article, we summarize the current knowledge of miRNAs as the promising biomarkers for nephrotic syndrome.
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20
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Korakas E, Ikonomidis I, Markakis K, Raptis A, Dimitriadis G, Lambadiari V. The Endothelial Glycocalyx as a Key Mediator of Albumin Handling and the Development of Diabetic Nephropathy. Curr Vasc Pharmacol 2020; 18:619-631. [PMID: 31889495 DOI: 10.2174/1570161118666191224120242] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/20/2019] [Accepted: 11/20/2019] [Indexed: 02/06/2023]
Abstract
The endothelial glycocalyx is a complex mesh of proteoglycans, glycoproteins and other soluble components, which cover the vascular endothelium. It plays an important role in many physiological processes including vascular permeability, transduction of shear stress and interaction of blood cells and other molecules with the vascular wall. Its complex structure makes its precise assessment challenging, and many different visualization techniques have been used with varying results. Diabetes, one of the main disease models where disorders of the glycocalyx are present, causes degradation of the glycocalyx through a variety of molecular pathways and especially through oxidative stress due to the action of reactive oxygen species. As the glycocalyx has been primarily studied in the glomerular endothelium, more evidence points towards a vital role in albumin handling and, consequently, in diabetic nephropathy. Therefore, the maintenance or restoration of the integrity of the glycocalyx seems a promising therapeutic target. In this review, we consider the structural and functional capacities of the endothelial glycocalyx, the available methods for its evaluation, the mechanisms through which diabetes leads to glycocalyx degradation and albuminuria, and possible treatment options targeting the glycocalyx.
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Affiliation(s)
- Emmanouil Korakas
- Second Department of Internal Medicine, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Ignatios Ikonomidis
- Second Cardiology Department, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Konstantinos Markakis
- Second Department of Internal Medicine, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Athanasios Raptis
- Second Department of Internal Medicine, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - George Dimitriadis
- Second Department of Internal Medicine, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Vaia Lambadiari
- Second Department of Internal Medicine, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
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21
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Jung HY, Lee CH, Choi JY, Cho JH, Park SH, Kim YL, Moon PG, Baek MC, Berm Park J, Hoon Kim Y, Ha Chung B, Lee SH, Kim CD. Potential urinary extracellular vesicle protein biomarkers of chronic active antibody-mediated rejection in kidney transplant recipients. J Chromatogr B Analyt Technol Biomed Life Sci 2020; 1138:121958. [DOI: 10.1016/j.jchromb.2019.121958] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 01/01/2023]
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Agrawal S, Merchant ML, Kino J, Li M, Wilkey DW, Gaweda AE, Brier ME, Chanley MA, Gooding JR, Sumner SJ, Klein JB, Smoyer WE. Predicting and Defining Steroid Resistance in Pediatric Nephrotic Syndrome Using Plasma Proteomics. Kidney Int Rep 2020; 5:66-80. [PMID: 31922062 PMCID: PMC6943770 DOI: 10.1016/j.ekir.2019.09.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 09/09/2019] [Indexed: 02/03/2023] Open
Abstract
INTRODUCTION Nephrotic syndrome (NS) is a characterized by massive proteinuria, edema, hypoalbuminemia, and dyslipidemia. Glucocorticoids (GCs), the primary therapy for >60 years, are ineffective in approximately 50% of adults and approximately 20% of children. Unfortunately, there are no validated biomarkers able to predict steroid-resistant NS (SRNS) or to define the pathways regulating SRNS. METHODS We performed proteomic analyses on paired pediatric NS patient plasma samples obtained both at disease presentation before glucocorticoid initiation and after approximately 7 weeks of GC therapy to identify candidate biomarkers able to either predict steroid resistance before treatment or define critical molecular pathways/targets regulating steroid resistance. RESULTS Proteomic analyses of 15 paired NS patient samples identified 215 prevalent proteins, including 13 candidate biomarkers that predicted SRNS before GC treatment, and 66 candidate biomarkers that mechanistically differentiated steroid-sensitive NS (SSNS) from SRNS. Ingenuity Pathway Analyses and protein networking pathways approaches further identified proteins and pathways associated with SRNS. Validation using 37 NS patient samples (24 SSNS/13 SRNS) confirmed vitamin D binding protein (VDB) and APOL1 as strong predictive candidate biomarkers for SRNS, and VDB, hemopexin (HPX), adiponectin (ADIPOQ), sex hormone-binding globulin (SHBG), and APOL1 as strong candidate biomarkers to mechanistically distinguish SRNS from SSNS. Logistic regression analysis identified a candidate biomarker panel (VDB, ADIPOQ, and matrix metalloproteinase 2 [MMP-2]) with significant ability to predict SRNS at disease presentation (P = 0.003; area under the receiver operating characteristic curve = 0.78). CONCLUSION Plasma proteomic analyses and immunoblotting of serial samples in childhood NS identified a candidate biomarker panel able to predict SRNS at disease presentation, as well as candidate molecular targets/pathways associated with clinical steroid resistance.
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Affiliation(s)
- Shipra Agrawal
- The Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, USA
- The Ohio State University, Columbus, Ohio, USA
| | | | - Jiro Kino
- The Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, USA
| | - Ming Li
- Kidney Disease Program, University of Louisville, Louisville, Kentucky, USA
| | - Daniel W. Wilkey
- Kidney Disease Program, University of Louisville, Louisville, Kentucky, USA
| | - Adam E. Gaweda
- Kidney Disease Program, University of Louisville, Louisville, Kentucky, USA
| | - Michael E. Brier
- Kidney Disease Program, University of Louisville, Louisville, Kentucky, USA
| | - Melinda A. Chanley
- The Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, USA
| | - Jessica R. Gooding
- National Institutes of Health Eastern Regional Comprehensive Metabolomics Resource Core at UNC, Chapel Hill, North Carolina, USA
- Discovery, Science and Technology, RTI International, Research Triangle Park, North Carolina, USA
| | - Susan J. Sumner
- National Institutes of Health Eastern Regional Comprehensive Metabolomics Resource Core at UNC, Chapel Hill, North Carolina, USA
- Nutrition Research Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Jon B. Klein
- Kidney Disease Program, University of Louisville, Louisville, Kentucky, USA
- Robley Rex VA Medical Center, Louisville, Kentucky, USA
| | - William E. Smoyer
- The Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, USA
- The Ohio State University, Columbus, Ohio, USA
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Nishimoto M, Murashima M, Kokubu M, Matsui M, Eriguchi M, Samejima KI, Akai Y, Tsuruya K. Pre-operative proteinuria and post-operative acute kidney injury in noncardiac surgery: the NARA-Acute Kidney Injury cohort study. Nephrol Dial Transplant 2019; 35:2111-2116. [DOI: 10.1093/ndt/gfz269] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 11/13/2019] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Little is known about the association between pre-operative proteinuria and post-operative acute kidney injury (AKI) in noncardiac surgery.
Methods
This is a retrospective cohort study. Adults who underwent noncardiac surgery under general anesthesia from 2007 to 2011 at Nara Medical University Hospital were included. Those with obstetric or urological surgery, missing data for analyses or pre-operative dialysis were excluded. Exposure of interest was pre-operative proteinuria, defined as (+) or more by dipstick test. The outcome variable was post-operative AKI, defined by Kidney Disease: Improving Global Outcomes criteria, within 1 week after surgery. Multivariable logistic regression analyses were performed.
Results
Among 5168 subjects, 309 (6.0%) developed AKI. Pre-operative proteinuria was independently associated with post-operative AKI, with an odds ratio (OR) [95% confidence interval (CI)] of 1.80 (1.30–2.51). A sensitivity analysis restricted to elective surgery yielded a similar result. As proteinuria increased, the association with AKI became stronger [OR (95% CI) 1.14 (0.75–1.73), 1.24 (0.79–1.95), 2.75 (1.74–4.35) and 3.95 (1.62–9.62) for urinary protein (+/−), (+), (2+) and (3+), respectively]. Subgroup analyses showed proteinuria was especially associated with post-operative AKI among subjects with renin–angiotensin system inhibitors, other anti-hypertensives, hypoalbuminemia or impaired renal function (P for interaction = 0.05, 0.003, 0.09 or 0.02, respectively).
Conclusions
In noncardiac surgery, pre-operative proteinuria was independently associated with post-operative AKI. Subjects with proteinuria should be managed with caution to avoid AKI peri-operatively.
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Affiliation(s)
| | - Miho Murashima
- Department of Nephrology, Nara Medical University, Nara, Japan
- Department of Nephrology, Nagoya City University Graduate School of Medical Science, Aichi, Japan
| | - Maiko Kokubu
- Department of Nephrology, Nara Prefecture General Medical Center, Nara, Japan
| | - Masaru Matsui
- Department of Nephrology, Nara Prefecture General Medical Center, Nara, Japan
| | | | | | - Yasuhiro Akai
- Department of Nephrology, Nara Medical University, Nara, Japan
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Candelier JJ, Lorenzo HK. Idiopathic nephrotic syndrome and serum permeability factors: a molecular jigsaw puzzle. Cell Tissue Res 2019; 379:231-243. [PMID: 31848752 DOI: 10.1007/s00441-019-03147-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 11/19/2019] [Indexed: 12/14/2022]
Abstract
Nephrotic syndrome is traditionally defined using the triad of edema, hypoalbuminemia, and proteinuria, but this syndrome is very heterogeneous and difficult to clarify. Its idiopathic form (INS) is probably the most harmful and essentially comprises two entities: minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS). We will consider some hypotheses regarding the mechanisms underlying INS: (i) the presence of several glomerular permeability factors in the sera of patients that alter the morphology and function of podocytes leading to proteinuria, (ii) the putative role of immune cells. Thanks to recent data, our understanding of these disorders is evolving towards a more multifactorial origin. In this context, circulating factors may be associated according to sequential kinetic mechanisms or micro-environmental changes that need to be determined. In addition, the resulting proteinuria may trigger more proteinuria enhancing the glomerular destabilization.
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Affiliation(s)
- Jean-Jacques Candelier
- INSERM U1197, Hôpital Paul Brousse, 14 Avenue Paul Vaillant Couturier, 94800, Villejuif, France.,Université Paris-Saclay, Campus Universitaire d'Orsay, 91405, Orsay, France
| | - Hans-Kristian Lorenzo
- INSERM U1197, Hôpital Paul Brousse, 14 Avenue Paul Vaillant Couturier, 94800, Villejuif, France. .,Université Paris-Saclay, Campus Universitaire d'Orsay, 91405, Orsay, France. .,Service de Néphrologie, Hôpital Bicêtre, Faculté de Médecine Paris-Saclay, 94270, Le Kremlin-Bicêtre, France.
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25
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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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26
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Stone H, Magella B, Bennett MR. The Search for Biomarkers to Aid in Diagnosis, Differentiation, and Prognosis of Childhood Idiopathic Nephrotic Syndrome. Front Pediatr 2019; 7:404. [PMID: 31681707 PMCID: PMC6805718 DOI: 10.3389/fped.2019.00404] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 09/18/2019] [Indexed: 12/13/2022] Open
Abstract
Identification of genes associated with childhood-onset nephrotic syndrome has significantly advanced our understanding of the pathogenesis of this complex disease over the past two decades, however the precise etiology in many cases remains unclear. At this time, we still rely on invasive kidney biopsy to determine the underlying cause of nephrotic syndrome in adults. In children, response to steroid therapy has been shown to be the best indicator of prognosis, and therefore all children are treated initially with corticosteroids. Because this strategy exposes a large number of children to the toxicities of steroids without providing any benefit, many researchers have sought to find a marker that could predict a patient's response to steroids at the time of diagnosis. Additionally, the identification of such a marker could provide prognostic information about a patient's response to medications, progression to end stage renal disease, and risk of disease recurrence following transplantation. Major advances have been made in understanding how genetic biomarkers can be used to predict a patient's response to therapies and disease course, especially after transplantation. Research attempting to identify urine- and serum-based biomarkers which could be used for the diagnosis, differentiation, and prognosis of nephrotic syndrome has become an area of emphasis. In this review, we explore the most exciting biomarkers and their potential clinical applications.
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Affiliation(s)
- Hillarey Stone
- Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Bliss Magella
- Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Michael R Bennett
- Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States
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27
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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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28
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Idiopathic Nephrotic Syndrome: Characteristics and Identification of Prognostic Factors. J Clin Med 2018; 7:jcm7090265. [PMID: 30205613 PMCID: PMC6162818 DOI: 10.3390/jcm7090265] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 09/03/2018] [Accepted: 09/07/2018] [Indexed: 12/12/2022] Open
Abstract
There are various histopathological forms of idiopathic nephrotic syndrome, including minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS). Whereas some relapse predictor factors have been identified in renal transplantation, the clinical future of idiopathic nephrotic syndrome in the native kidney remains uncertain. We designed a multicentric retrospective descriptive cohort study including all patients aged 15 years and over whose renal biopsy confirmed MCD or FSGS between January 2007 and December 2014. We studied 165 patients with idiopathic nephrotic syndrome; 97 with MCD and 68 with FSGS. In the MCD cohort, 91.7% of patients were treated with corticosteroids for a median total duration of 13 months. During 45 months of follow-up, 92.8% of patients achieved remission and 45.5% experienced relapse. In this cohort, 5% of patients experienced terminal kidney disease. With respect to FSGS patients, 51.5% were treated with corticosteroids for a median total duration of 15 months. During 66 months of follow-up, 73.5% of patients achieved remission and 20% experienced relapse. In this cohort, 26.5% of patients experienced terminal kidney disease. No statistical association was observed between clinical and biological initial presentation and relapse occurrence. This study describes the characteristics of a cohort of patients with the nephrotic idiopathic syndromes of MCD and FSGS from the time of renal biopsy and throughout follow-up.
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29
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Dumas De La Roque C, Combe C, Rigothier C. [Up to date of pathophysiology mechanism of idiopathic nephrotic syndromes: Minimal change disease and focal and segmental glomerulosclerosis]. Nephrol Ther 2018; 14:501-506. [PMID: 30150079 DOI: 10.1016/j.nephro.2018.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 06/03/2018] [Indexed: 01/27/2023]
Abstract
Idiopathic nephrotic syndrome represents up to 30% of adult glomerulopathies. However, its prognosis according to remission, relapse and renal failure remains unchanged since the 80s and prediction remains difficult. Physiopathology of adult idiopathic nephrotic syndrome is complex and multifactorial, including immunologic and environmental factors and a putative permeability-circulating factor, still unknown. In this point of view, we propose to summarize actual knowledge about idiopathic minimal change disease and focal and segmental glomerulosclerosis physiopathology.
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Affiliation(s)
- Charlotte Dumas De La Roque
- Service de néphrologie transplantation et dialyse, centre hospitalier universitaire de Bordeaux, 33076 Bordeaux, France.
| | - Christian Combe
- Service de néphrologie transplantation et dialyse, centre hospitalier universitaire de Bordeaux, 33076 Bordeaux, France; Inserm U1026, université de Bordeaux, 33076 Bordeaux, France
| | - Claire Rigothier
- Service de néphrologie transplantation et dialyse, centre hospitalier universitaire de Bordeaux, 33076 Bordeaux, France; Inserm U1026, université de Bordeaux, 33076 Bordeaux, France
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30
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Ozeki T, Ando M, Yamaguchi M, Katsuno T, Kato S, Yasuda Y, Tsuboi N, Maruyama S. Treatment patterns and steroid dose for adult minimal change disease relapses: A retrospective cohort study. PLoS One 2018; 13:e0199228. [PMID: 29912938 PMCID: PMC6005527 DOI: 10.1371/journal.pone.0199228] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 06/04/2018] [Indexed: 01/10/2023] Open
Abstract
Background In patients with adult minimal change disease (MCD), proteinuria relapse is a problem to solve. However, the optimal relapse treatment regimen remains unclear regarding steroid dose. We described the treatment pattern of adult MCD patients and evaluated the appropriate steroid dose for relapse treatment. Methods This retrospective multicenter cohort study included 192 patients with adult biopsy-proven MCD from 14 hospitals in Japan. The prescription pattern of immunosuppressive drugs in relapse was reviewed. To assess the association between steroid dose used for relapse and subsequent outcomes, data of patients with tapered prednisolone (PSL) dosage to <10 mg/day before the first relapse in whom the dose was subsequently increased to ≥10 mg/day were extracted and assigned to the High-PSL or Low-PSL groups, based on the median dose of 20 mg/day. Multivariate Cox proportional hazard model and propensity score analysis with multiple imputations were conducted to compare their clinical course. Results During a median observation period of 37.6 months, 186/192 (96.9%) patients achieved complete remission (CR) and 100 (52.1%) relapsed. The median urinary protein level at the first relapse was 3.12 g/gCr or g/day. The proportion of non-steroidal immunosuppressant use increased with relapses; cyclosporine was the most common. No significant differences were found in the second relapse, frequent relapses, or adverse events between High-PSL (n = 34) and Low-PSL (n = 36) groups. A multivariate Cox proportional hazard model revealed that the hazard ratios adjusted with propensity score for the second relapse were 0.94 (High-PSL vs. Low-PSL; 95% confidence interval, 0.42–2.10; P = 0.88) and 0.82 (PSL dose per 10 mg/day; 95% confidence interval, 0.58–1.16; P = 0.25). Conclusions Among patients in CR with PSL dose <10 mg/day, higher steroid dose (PSL >20 mg/day) was not associated with favorable outcomes after the first relapse as compared to lower dose (10–20 mg/day).
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Affiliation(s)
- Takaya Ozeki
- Department of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masahiko Ando
- Center for Advanced Medicine and Clinical Research, Nagoya University Hospital, Nagoya, Japan
| | - Makoto Yamaguchi
- Department of Nephrology, Yokkaichi Municipal Hospital, Yokkaichi, Japan
| | - Takayuki Katsuno
- Department of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Sawako Kato
- Department of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshinari Yasuda
- Department of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Naotake Tsuboi
- Department of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shoichi Maruyama
- Department of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan
- * E-mail:
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31
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Bertelli R, Bonanni A, Caridi G, Canepa A, Ghiggeri GM. Molecular and Cellular Mechanisms for Proteinuria in Minimal Change Disease. Front Med (Lausanne) 2018; 5:170. [PMID: 29942802 PMCID: PMC6004767 DOI: 10.3389/fmed.2018.00170] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 05/15/2018] [Indexed: 12/15/2022] Open
Abstract
Minimal Change Disease (MCD) is a clinical condition characterized by acute nephrotic syndrome, no evident renal lesions at histology and good response to steroids. However, frequent recurrence of the disease requires additional therapies associated with steroids. Such multi-drug dependence and frequent relapses may cause disease evolution to focal and segmental glomerulosclerosis (FSGS) over time. The differences between the two conditions are not well defined, since molecular mechanisms may be shared by the two diseases. In some cases, genetic analysis can make it possible to distinguish MCD from FSGS; however, there are cases of overlap. Several hypotheses on mechanisms underlying MCD and potential molecular triggers have been proposed. Most studies were conducted on animal models of proteinuria that partially mimic MCD and may be useful to study glomerulosclerosis evolution; however, they do not demonstrate a clear-cut separation between MCD and FSGS. Puromycin Aminonucleoside and Adriamycin nephrosis are models of glomerular oxidative damage, characterized by loss of glomerular basement membrane polyanions resembling MCD at the onset and, at more advanced stages, by glomerulosclerosis resembling FSGS. Also Buffalo/Mna rats present initial lesions of MCD, subsequently evolving to FSGS; this mechanism of renal damage is clearer since this rat strain inherits the unique characteristic of overexpressing Th2 cytokines. In Lipopolysaccharide nephropathy, an immunological condition of renal toxicity linked to B7-1(CD80), mice develop transient proteinuria that lasts a few days. Overall, animal models are useful and necessary considering that they reproduce the evolution from MCD to FSGS that is, in part, due to persistence of proteinuria. The role of T/Treg/Bcells on human MCD has been discussed. Many cytokines, immunomodulatory mechanisms, and several molecules have been defined as a specific cause of proteinuria. However, the hypothesis of a single cell subset or molecule as cause of MCD is not supported by research and an interactive process seems more logical. The implication or interactive role of oxidants, Th2 cytokines, Th17, Tregs, B7-1(CD80), CD40/CD40L, c-Mip, TNF, uPA/suPAR, Angiopoietin-like 4 still awaits a definitive confirmation. Whole genome sequencing studies could help to define specific genetic features that justify a definition of MCD as a “clinical-pathology-genetic entity.”
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Affiliation(s)
| | | | | | - Alberto Canepa
- Nephrology, Dialysis, Transplantation Unit, Integrated Department of Pediatrics and Hemato-Oncology Sciences, Istituto Giannina Gaslini IRCCS, Genoa, Italy
| | - G M Ghiggeri
- Laboratory of Molecular Nephrology, Genoa, Italy.,Nephrology, Dialysis, Transplantation Unit, Integrated Department of Pediatrics and Hemato-Oncology Sciences, Istituto Giannina Gaslini IRCCS, Genoa, Italy
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32
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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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33
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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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Downie ML, Gallibois C, Parekh RS, Noone DG. Nephrotic syndrome in infants and children: pathophysiology and management. Paediatr Int Child Health 2017; 37:248-258. [PMID: 28914167 DOI: 10.1080/20469047.2017.1374003] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Nephrotic syndrome is defined by nephrotic-range proteinuria (≥40 mg/m2/hour or urine protein/creatinine ratio ≥200 mg/mL or 3+ protein on urine dipstick), hypoalbuminaemia (<25 g/L) and oedema. This review focuses on the classification, epidemiology, pathophysiology, management strategies and prognosis of idiopathic nephrotic syndrome of childhood, and includes a brief overview of the congenital forms.
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Affiliation(s)
- Mallory L Downie
- a Department of Paediatrics , Univeristy of Toronto , Toronto , Canada.,b Division of Nephrology , The Hospital for Sick Children , Toronto , Canada.,c Department of Paediatrics , University of Toronto , Toronto , Canada
| | - Claire Gallibois
- d Department of Medicine , Royal College of Surgeons in Ireland , Dublin , Ireland
| | - Rulan S Parekh
- a Department of Paediatrics , Univeristy of Toronto , Toronto , Canada.,b Division of Nephrology , The Hospital for Sick Children , Toronto , Canada.,c Department of Paediatrics , University of Toronto , Toronto , Canada.,d Department of Medicine , Royal College of Surgeons in Ireland , Dublin , Ireland.,e Child Health Evaluative Sciences, Research Institute , The Hospital for Sick Children , Toronto , Canada.,f Division of Nephrology , University Health Network , Toronto , Canada.,g Dalla Lana School of Public Health , University of Toronto , Toronto , Canada
| | - Damien G Noone
- a Department of Paediatrics , Univeristy of Toronto , Toronto , Canada.,b Division of Nephrology , The Hospital for Sick Children , Toronto , Canada.,c Department of Paediatrics , University of Toronto , Toronto , Canada
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35
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Interaction of CD80 with Neph1: a potential mechanism of podocyte injury. Clin Exp Nephrol 2017; 22:508-516. [PMID: 29022109 DOI: 10.1007/s10157-017-1489-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 09/14/2017] [Indexed: 12/27/2022]
Abstract
BACKGROUND The induction of CD80 on podocytes has been shown in animal models of podocyte injury and in certain cases of nephrotic syndrome. In a lipopolysaccharide (LPS)-induced mouse model of albuminuria, we have recently shown a signalling axis of LPS-myeloid cell activation-TNFα production-podocyte CD80 induction-albuminuria. Therefore, in this report, we investigated the cellular and molecular consequences of TNFα addition and CD80 expression on cultured podocytes. METHODS A murine podocyte cell line was used for TNFα treatment and for over-expressing CD80. Expression and localization of various podocyte proteins was analysed by reverse transcriptase-polymerase chain reaction, western blotting and immunofluorescence. HEK293 cells were used to biochemically characterize interactions. RESULTS Podocytes treated with LPS in vitro did not cause CD80 upregulation but TNFα treatment was associated with an increase in CD80 levels, actin derangement and poor wound healing. Podocytes stably expressing CD80 showed actin derangement and co-localization with Neph1. CD80 and Neph1 interaction was confirmed by pull down assays of CD80 and Neph1 transfected in HEK293 cells. CONCLUSION Addition of TNFα to podocytes causes CD80 upregulation, actin reorganization and podocyte injury. Overexpressed CD80 and Neph1 interact via their extracellular domain. This interaction implies a mechanism of slit diaphragm disruption and possible use of small molecules that disrupt CD80-Neph1 interaction as a potential for treatment of nephrotic syndrome associated with CD80 upregulation.
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36
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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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37
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Multiple Targets for Novel Therapy of FSGS Associated with Circulating Permeability Factor. BIOMED RESEARCH INTERNATIONAL 2017; 2017:6232616. [PMID: 28951873 PMCID: PMC5603123 DOI: 10.1155/2017/6232616] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 05/10/2017] [Accepted: 06/15/2017] [Indexed: 01/13/2023]
Abstract
A plasma component is responsible for altered glomerular permeability in patients with focal segmental glomerulosclerosis. Evidence includes recurrence after renal transplantation, remission after plasmapheresis, proteinuria in infants of affected mothers, transfer of proteinuria to experimental animals, and impaired glomerular permeability after exposure to patient plasma. Therapy may include decreasing synthesis of the injurious agent, removing or blocking its interaction with cells, or blocking signaling or enhancing cell defenses to restore the permeability barrier and prevent progression. Agents that may prevent the synthesis of the permeability factor include cytotoxic agents or aggressive chemotherapy. Extracorporeal therapies include plasmapheresis, immunoadsorption with protein A or anti-immunoglobulin, or lipopheresis. Oral or intravenous galactose also decreases Palb activity. Studies of glomeruli have shown that several strategies prevent the action of FSGS sera. These include blocking receptor-ligand interactions, modulating cell reactions using indomethacin or eicosanoids 20-HETE or 8,9-EET, and enhancing cytoskeleton and protein interactions using calcineurin inhibitors, glucocorticoids, or rituximab. We have identified cardiotrophin-like cytokine factor 1 (CLCF-1) as a candidate for the permeability factor. Therapies specific to CLCF-1 include potential use of cytokine receptor-like factor (CRLF-1) and inhibition of Janus kinase 2. Combined therapy using multiple modalities offers therapy to reverse proteinuria and prevent scarring.
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Glucocorticoid therapy regulates podocyte motility by inhibition of Rac1. Sci Rep 2017; 7:6725. [PMID: 28751734 PMCID: PMC5532274 DOI: 10.1038/s41598-017-06810-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 06/19/2017] [Indexed: 02/03/2023] Open
Abstract
Nephrotic syndrome (NS) occurs when the glomerular filtration barrier becomes excessively permeable leading to massive proteinuria. In childhood NS, immune system dysregulation has been implicated and increasing evidence points to the central role of podocytes in the pathogenesis. Children with NS are typically treated with an empiric course of glucocorticoid (Gc) therapy; a class of steroids that are activating ligands for the glucocorticoid receptor (GR) transcription factor. Although Gc-therapy has been the cornerstone of NS management for decades, the mechanism of action, and target cell, remain poorly understood. We tested the hypothesis that Gc acts directly on the podocyte to produce clinically useful effects without involvement of the immune system. In human podocytes, we demonstrated that the basic GR-signalling mechanism is intact and that Gc induced an increase in podocyte barrier function. Defining the GR-cistrome identified Gc regulation of motility genes. These findings were functionally validated with live-cell imaging. We demonstrated that treatment with Gc reduced the activity of the pro-migratory small GTPase regulator Rac1. Furthermore, Rac1 inhibition had a direct, protective effect on podocyte barrier function. Our studies reveal a new mechanism for Gc action directly on the podocyte, with translational relevance to designing new selective synthetic Gc molecules.
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Abstract
Podocytes, the postmitotic and highly branched epithelial cells of the glomerulus, play a pivotal role for the function of the glomerular filtration barrier and the development of chronic kidney disease. It has long been discussed whether podocytes in vivo are motile and can laterally migrate in a coordinated way along the capillaries until they reach the position of naked glomerular basement membrane often found in podocytopathies. Such motility would also be the prerequisite for the replacement of lost podocytes by progenitor cells. Additionally, the change of the podocyte foot processes from a normal to an effaced morphology, like it is found in many kidney diseases, would require a dynamic behavior of podocytes. Since the actin cytoskeleton is expressed in podocytes in vitro and in vivo and the morphology of podocytes is highly dependent on actin, actin-associated, and actin-regulating proteins, it was assumed that podocytes are dynamic and motile. After earlier technical limitations had been overcome and novel microscopic techniques like multiphoton microscopy had been developed, it became possible to continuously study the behavior of podocytes in living rodents and zebrafish larvae under physiological and pathological conditions. Recent in vivo microscopic studies in different model organisms suggest that lateral migration of podocytes in situ is a very unlikely event and only dynamic apical cell protrusions can be observed under pathological conditions. This review discusses recent findings concerning different forms of motility (like lateral translocative (LTM), apical translocative (ATM), and stationary motility (SM)) and their role for podocytopathies.
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Affiliation(s)
- Nicole Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17487, Greifswald, Germany. .,Institut für Anatomie und Zellbiologie, Universitätsmedizin Greifswald, Friedrich-Loeffler-Str. 23c, 17487, Greifswald, Germany.
| | - Florian Siegerist
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17487, Greifswald, Germany
| | - Karlhans Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17487, Greifswald, Germany
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Abstract
The role of complement (C) in the pathogenesis or progression of focal segmental glomerulosclerosis (FSGS) is uncertain. The present study assessed the relationship between serum C3, the baseline characteristics, and the progression of FSGS in the cohort and identified the clinical implications of serum C3 levels in patients with FSGS. Compared to the patients with C3 ≥ 85 mg/dL (N = 474), those with C3 < 85 mg/dL (N = 117) presented a higher level of serum creatinine, lower levels of eGFR, hemoglobin, proteinuria, triglyceride, cholesterol, IgA, as well as, severe tubulointerstitial injury (TI). Of the 221 patients with a mean follow-up of 53.3 months, the risk of reaching end-stage renal disease (ESRD) was significantly higher in patients with low serum C3 level (p < 0.001). An additional 40 patients with primary FSGS revealed a significant correlation between MAC and AP (p = 0.003), MAC and serum C3 (p = 0.018), and AP and serum C3 (p = 0.028). Compared to patients with none-to-mild TI, those with moderate-to-severe TI exhibited a lower level of serum C3 and AP, and a higher level of serum MAC. In conclusion, complement activation occurring in patients with FSGS is associated with clinical and histological severities. Low serum C3 was an independent risk factor for poor renal outcome in patients with FSGS.
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Abstract
Idiopathic nephrotic syndrome (INS) is one of the most common glomerular diseases in children and adults, and the central event is podocyte injury. INS is a heterogeneous disease, and treatment is largely empirical and in many cases unsuccessful, and steroids are the initial mainstay of therapy. Close to 70% of children with INS have some response to steroids and are labelled as steroid-‘sensitive’, and the rest as steroid-‘resistant’ (also termed focal segmental glomerulosclerosis), and single-gene mutations underlie a large proportion of the latter group. The burden of morbidity is enormous, both to patients with lifelong chronic disease and to health services, particularly in managing dialysis and transplantation. The target cell of nephrotic syndrome is the glomerular podocyte, and podocyte biology research has exploded over the last 15 years. Major advances in genetic and biological understanding now put clinicians and researchers at the threshold of a major reclassification of the disease and testing of targeted therapies both identified and novel. That potential is based on complete genetic analysis, deep clinical phenotyping, and the introduction of mechanism-derived biomarkers into clinical practice. INS can now be split off into those with a single-gene defect, of which currently at least 53 genes are known to be causative, and the others. Of the others, the majority are likely to be immune-mediated and caused by the presence of a still-unknown circulating factor or factors, and whether there is a third (or more) mechanistic group or groups remains to be discovered. Treatment is therefore now being refined towards separating out the monogenic cases to minimise immunosuppression and further understanding how best to stratify and appropriately direct immunosuppressive treatments within the immune group. Therapies directed specifically towards the target cell, the podocyte, are in their infancy but hold considerable promise for the near future.
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Affiliation(s)
| | - Moin Saleem
- University of Bristol, Bristol Royal Hospital for Children, Bristol, UK
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Abstract
Minimal change disease (MCD) is a major cause of idiopathic nephrotic syndrome (NS), characterized by intense proteinuria leading to edema and intravascular volume depletion. In adults, it accounts for approximately 15% of patients with idiopathic NS, reaching a much higher percentage at younger ages, up to 70%-90% in children >1 year of age. In the pediatric setting, a renal biopsy is usually not performed if presentation is typical and the patient responds to therapy with oral prednisone at conventional doses. Therefore, in this setting steroid-sensitive NS can be considered synonymous with MCD. The pathologic hallmark of disease is absence of visible alterations by light microscopy and effacement of foot processes by electron microscopy. Although the cause is unknown and it is likely that different subgroups of disease recognize a different pathogenesis, immunologic dysregulation and modifications of the podocyte are thought to synergize in altering the integrity of the glomerular basement membrane and therefore determining proteinuria. The mainstay of therapy is prednisone, but steroid-sensitive forms frequently relapse and this leads to a percentage of patients requiring second-line steroid-sparing immunosuppression. The outcome is variable, but forms of MCD that respond to steroids usually do not lead to chronic renal damage, whereas forms that are unresponsive to steroids may subsequently reveal themselves as FSGS. However, in a substantial number of patients the disease is recurrent and requires long-term immunosuppression, with significant morbidity because of side effects. Recent therapeutic advances, such as the use of anti-CD20 antibodies, have provided long-term remission off-therapy and suggest new hypotheses for disease pathogenesis.
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Affiliation(s)
- Marina Vivarelli
- Division of Nephrology and Dialysis, Bambino Gesù Children’s Hospital, IRCCS, Rome, Italy; and
| | - Laura Massella
- Division of Nephrology and Dialysis, Bambino Gesù Children’s Hospital, IRCCS, Rome, Italy; and
| | - Barbara Ruggiero
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò”, IRCCS – Istituto di Ricerche Farmacologiche Mario Negri, Ranica, Bergamo, Italy
| | - Francesco Emma
- Division of Nephrology and Dialysis, Bambino Gesù Children’s Hospital, IRCCS, Rome, Italy; and
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Jasim DA, Murphy S, Newman L, Mironov A, Prestat E, McCaffey J, Meńard-Moyon C, Rodrigues AF, Bianco A, Haigh S, Lennon R, Kostarelos K. The Effects of Extensive Glomerular Filtration of Thin Graphene Oxide Sheets on Kidney Physiology. ACS NANO 2016; 10:10753-10767. [PMID: 27936585 PMCID: PMC7614378 DOI: 10.1021/acsnano.6b03358] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Understanding how two-dimensional (2D) nanomaterials interact with the biological milieu is fundamental for their development toward biomedical applications. When thin, individualized graphene oxide (GO) sheets were administered intravenously in mice, extensive urinary excretion was observed, indicating rapid transit across the glomerular filtration barrier (GFB). A detailed analysis of kidney function, histopathology, and ultrastructure was performed, along with the in vitro responses of two highly specialized GFB cells (glomerular endothelial cells and podocytes) following exposure to GO. We investigated whether these cells preserved their unique barrier function at doses 100 times greater than the dose expected to reach the GFB in vivo. Both serum and urine analyses revealed that there was no impairment of kidney function up to 1 month after injection of GO at escalating doses. Histological examination suggested no damage to the glomerular and tubular regions of the kidneys. Ultrastructural analysis by transmission electron microscopy showed absence of damage, with no change in the size of podocyte slits, endothelial cell fenestra, or the glomerular basement membrane width. The endothelial and podocyte cell cultures regained their full barrier function after >48 h of GO exposure, and cellular uptake was significant in both cell types after 24 h. This study provided a previously unreported understanding of the interaction between thin GO sheets with different components of the GFB in vitro and in vivo to highlight that the glomerular excretion of significant amounts of GO did not induce any signs of acute nephrotoxicity or glomerular barrier dysfunction.
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Affiliation(s)
- Dhifaf A. Jasim
- Nanomedicine Laboratory, Faculty of Biology, Medicine and Health, Manchester M13 9NT, United Kingdom
- National Graphene Institute, Manchester M13 9NT, United Kingdom
| | - Stephanie Murphy
- Wellcome Trust Centre for Cell-Matrix Research, Manchester M13 9NT, United Kingdom
| | - Leon Newman
- Nanomedicine Laboratory, Faculty of Biology, Medicine and Health, Manchester M13 9NT, United Kingdom
- National Graphene Institute, Manchester M13 9NT, United Kingdom
| | | | - Eric Prestat
- National Graphene Institute, Manchester M13 9NT, United Kingdom
- School of Materials, University of Manchester, Manchester M13 9PL, United Kingdom
| | - James McCaffey
- Wellcome Trust Centre for Cell-Matrix Research, Manchester M13 9NT, United Kingdom
- Department of Pediatric Nephrology, Royal Manchester Children’s Hospital, Central Manchester University Hospitals NHS Foundation Trust (CMFT), Manchester Academic Health Science Centre, Manchester M13 9NT, United Kingdom
| | - Cećilia Meńard-Moyon
- University of Strasbourg, CNRS, Immunopathology and Therapeutic Chemistry, UPR 3572, 67000 Strasbourg, France
| | - Artur Filipe Rodrigues
- Nanomedicine Laboratory, Faculty of Biology, Medicine and Health, Manchester M13 9NT, United Kingdom
- National Graphene Institute, Manchester M13 9NT, United Kingdom
| | - Alberto Bianco
- University of Strasbourg, CNRS, Immunopathology and Therapeutic Chemistry, UPR 3572, 67000 Strasbourg, France
| | - Sarah Haigh
- National Graphene Institute, Manchester M13 9NT, United Kingdom
- School of Materials, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Rachel Lennon
- Wellcome Trust Centre for Cell-Matrix Research, Manchester M13 9NT, United Kingdom
- Department of Pediatric Nephrology, Royal Manchester Children’s Hospital, Central Manchester University Hospitals NHS Foundation Trust (CMFT), Manchester Academic Health Science Centre, Manchester M13 9NT, United Kingdom
- Corresponding Authors
| | - Kostas Kostarelos
- Nanomedicine Laboratory, Faculty of Biology, Medicine and Health, Manchester M13 9NT, United Kingdom
- National Graphene Institute, Manchester M13 9NT, United Kingdom
- Corresponding Authors
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44
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Pathogenesis of proteinuria in idiopathic minimal change disease: molecular mechanisms. Pediatr Nephrol 2016; 31:2179-2189. [PMID: 27384691 DOI: 10.1007/s00467-016-3379-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/07/2016] [Accepted: 03/14/2016] [Indexed: 12/13/2022]
Abstract
Minimal change disease (MCD) is the most common type of nephrotic syndrome in children and adolescents. The pathogenesis of proteinuria in this condition is currently being reassessed. Following the Shalhoub hypothesis, most efforts have been placed on identifying the putative circulating factor, but recent advancement in podocyte biology has focused attention on the molecular changes at the glomerular capillary wall, which could explain the mechanism of proteinuria in MCD. This report critically reviews current knowledge on the different postulated mechanisms at the glomerular capillary wall level for increased permeability to plasma proteins in MCD. The report helps describe the rationale behind novel therapies and suggests future targeted therapies for MCD.
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45
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Zea AH, Stewart T, Ascani J, Tate DJ, Finkel-Jimenez B, Wilk A, Reiss K, Smoyer WE, Aviles DH. Activation of the IL-2 Receptor in Podocytes: A Potential Mechanism for Podocyte Injury in Idiopathic Nephrotic Syndrome? PLoS One 2016; 11:e0157907. [PMID: 27389192 PMCID: PMC4936730 DOI: 10.1371/journal.pone.0157907] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 06/07/2016] [Indexed: 12/16/2022] Open
Abstract
The renal podocyte plays an important role in maintaining the structural integrity of the glomerular basement membrane. We have previously reported that patients with idiopathic nephrotic syndrome (INS) have increased IL-2 production. We hypothesized that podocytes express an IL-2 receptor (IL-2R) and signaling through this receptor can result in podocyte injury. To confirm the presence of the IL-2R, we tested a conditionally immortalized murine podocyte cell line by flow cytometry, qPCR, and Western blot. To test for the presence of the IL-2R in vivo, immunohistochemical staining was performed on human renal biopsies in children with FSGS and control. Podocytes were stimulated with IL-2 in vitro, to study signaling events via the JAK/STAT pathway. The results showed that stimulation with IL-2 resulted in increased mRNA and protein expression of STAT 5a, phosphorylated STAT 5, JAK 3, and phosphorylated JAK 3. We then investigated for signs of cellular injury and the data showed that pro-apoptotic markers Bax and cFLIP were significantly increased following IL-2 exposure, whereas LC3 II was decreased. Furthermore, mitochondrial depolarization and apoptosis were both significantly increased following activation of the IL-2R. We used a paracellular permeability assay to monitor the structural integrity of a podocyte monolayer following IL-2 exposure. The results showed that podocytes exposed to IL-2 have increased albumin leakage across the monolayer. We conclude that murine podocytes express the IL-2R, and that activation through the IL-2R results in podocyte injury.
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Affiliation(s)
- Arnold H. Zea
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Tyrus Stewart
- Department of Pediatric Nephrology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Jeannine Ascani
- Department of Research Ochsner Biobank, Ochsner Health System, New Orleans, Louisiana, United States of America
| | - David J. Tate
- Eurofins Central Analytical Laboratories, New Orleans, Louisiana, United States of America
| | - Beatriz Finkel-Jimenez
- Department of Medical Microbiology and Immunology, American University of the Caribbean School of Medicine, Coral Gables, Florida, United States of America
| | - Anna Wilk
- Department of Genetics, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Krzysztof Reiss
- Department of Genetics, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - William E. Smoyer
- Department of Nephrology, Nationwide Children’s Hospital, Columbus, Ohio, United States of America
| | - Diego H. Aviles
- Department of Pediatric Nephrology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
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46
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Schrödl W, Büchler R, Wendler S, Reinhold P, Muckova P, Reindl J, Rhode H. Acute phase proteins as promising biomarkers: Perspectives and limitations for human and veterinary medicine. Proteomics Clin Appl 2016; 10:1077-1092. [PMID: 27274000 DOI: 10.1002/prca.201600028] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/09/2016] [Accepted: 06/01/2016] [Indexed: 12/23/2022]
Abstract
Acute phase proteins (APPs) are highly conserved plasma proteins that are increasingly secreted by the liver in response to a variety of injuries, independently of their location and cause. APPs favor the systemic regulation of defense, coagulation, proteolysis, and tissue repair. Various APPs have been applied as general diagnostic parameters for a long time. Through proteomic techniques, more and more APPs have been discovered to be differentially altered. Since they are not consistently explainable by a stereotypic hepatic expression of sets of APPs, most of these results have unfortunately been neglected or attributed to the nonspecificity of the acute phase reaction. Moreover, it appears that various extrahepatic tissues are also able to express APPs. These extrahepatic APPs show focally specific roles in tissue homeostasis and repair and are released primarily into interstitial and distal fluids. Since these focal proteins might leak into the circulatory system, mixtures of hepatic and extrahepatic APP species can be expected in blood. Hence, a selective alteration of parts of APPs might be expected. There are several hints on multiple molecular forms and fragments of tissue-derived APPs. These differences offer the chance for multiple selective determinations. Thus, specific proteoforms might indeed serve as tissue-specific disease indicators.
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Affiliation(s)
- Wieland Schrödl
- Institute of Bacteriology and Mycology, Veterinary Faculty, University Leipzig, Germany
| | - Rita Büchler
- Institute of Biochemistry I, University Hospital Jena, Germany
| | - Sindy Wendler
- Institute of Biochemistry I, University Hospital Jena, Germany
| | - Petra Reinhold
- Institute of Molecular Pathogenesis at 'Friedrich Loeffler Institut', Federal Research Institute for Animal Health, Jena, Germany
| | - Petra Muckova
- Institute of Biochemistry I, University Hospital Jena, Germany.,Clinic of Neurology, University Hospital Jena, Germany
| | - Johanna Reindl
- Institute of Biochemistry I, University Hospital Jena, Germany
| | - Heidrun Rhode
- Institute of Biochemistry I, University Hospital Jena, Germany
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47
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Kim SH, Park SJ, Han KH, Kronbichler A, Saleem MA, Oh J, Lim BJ, Shin JI. Pathogenesis of minimal change nephrotic syndrome: an immunological concept. KOREAN JOURNAL OF PEDIATRICS 2016; 59:205-11. [PMID: 27279884 PMCID: PMC4897155 DOI: 10.3345/kjp.2016.59.5.205] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 03/20/2015] [Accepted: 11/26/2015] [Indexed: 01/08/2023]
Abstract
Idiopathic nephrotic syndrome (INS) in children is characterized by massive proteinuria and hypoalbuminemia. Minimal change nephrotic syndrome (MCNS) is the most common form of INS in children. The pathogenesis of MCNS still remains unclear, however, several hypotheses have been recently proposed. For several decades, MCNS has been considered a T-cell disorder, which causes the impairment of the glomerular filtration barrier with the release of different circulating factors. Increased levels of several cytokines are also suggested. Recently, a "two-hit" theory was proposed that included the induction of CD80 (B7-1) and regulatory T-cell (Treg) dysfunction, with or without impaired autoregulatory functions of the podocyte. In contrast to the well-established involvement of T cells, the role of B cells has not been clearly identified. However, B-cell biology has recently gained more attention, because rituximab (a monoclonal antibody directed against CD20-bearing cells) demonstrated a very good therapeutic response in the treatment of childhood and adult MCNS. Here, we discuss recent insights into the pathogenesis of MCNS in children.
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Affiliation(s)
- Seong Heon Kim
- Department of Pediatrics, Pusan National University Children's Hospital, Yangsan, Korea
| | - Se Jin Park
- Department of Pediatrics, Daewoo General Hospital, Ajou University School of Medicine, Geoje, Korea
| | - Kyoung Hee Han
- Department of Pediatrics, Jeju National University School of Medicine, Jeju, Korea
| | - Andreas Kronbichler
- Department of Internal Medicine IV (Nephrology and Hypertension), Medical University Innsbruck, Innsbruck, Austria
| | - Moin A Saleem
- Children's and Academic Renal Unit, Dorothy Hodgkin Building-University of Bristol, Bristol, UK
| | - Jun Oh
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Beom Jin Lim
- Department of Pathology, Yonsei University College of Medicine, Seoul, Korea
| | - Jae Il Shin
- Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
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Wada Y, Abe M, Moritani H, Mitori H, Kondo M, Tanaka-Amino K, Eguchi M, Imasato A, Inoki Y, Kajiyama H, Mimura T, Tomura Y. Original Research: Potential of urinary nephrin as a biomarker reflecting podocyte dysfunction in various kidney disease models. Exp Biol Med (Maywood) 2016; 241:1865-76. [PMID: 27216597 DOI: 10.1177/1535370216651937] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 04/26/2016] [Indexed: 01/01/2023] Open
Abstract
Urinary nephrin is a potential non-invasive biomarker of disease. To date, however, most studies of urinary nephrin have been conducted in animal models of diabetic nephropathy, and correlations between urinary nephrin-to-creatinine ratio and other parameters have yet to be evaluated in animal models or patients of kidney disease with podocyte dysfunction. We hypothesized that urinary nephrin-to-creatinine ratio can be up-regulated and is negatively correlated with renal nephrin mRNA levels in animal models of kidney disease, and that increased urinary nephrin-to-creatinine ratio levels are attenuated following administration of glucocorticoids. In the present study, renal nephrin mRNA, urinary nephrin-to-creatinine ratio, urinary protein-to-creatinine ratio, and creatinine clearance ratio were measured in animal models of adriamycin nephropathy, puromycin aminonucleoside nephropathy, anti-glomerular basement membrane glomerulonephritis, and 5/6 nephrectomy. The effects of prednisolone on urinary nephrin-to-creatinine ratio and other parameters in puromycin aminonucleoside (single injection) nephropathy rats were also investigated. In all models tested, urinary nephrin-to-creatinine ratio and urinary protein-to-creatinine ratio increased, while renal nephrin mRNA and creatinine clearance ratio decreased. Urinary nephrin-to-creatinine ratio exhibited a significant negative correlation with renal nephrin mRNA in almost all models, as well as a significant positive correlation with urinary protein-to-creatinine ratio and a significant negative correlation with creatinine clearance ratio. Urinary protein-to-creatinine ratio exhibited a significant negative correlation with renal nephrin mRNA. Following the administration of prednisolone to puromycin aminonucleoside (single injection) nephropathy rats, urinary nephrin-to-creatinine ratio was significantly suppressed and exhibited a significant positive correlation with urinary protein-to-creatinine ratio. In addition, the decrease in number of glomerular Wilms tumor antigen-1-positive cells was attenuated, and urinary nephrin-to-creatinine ratio exhibited a significant negative correlation in these cells. In conclusion, these results suggest that urinary nephrin-to-creatinine ratio level is a useful and reliable biomarker for predicting the amelioration of podocyte dysfunction by candidate drugs in various kidney disease models with podocyte dysfunction. This suggestion will also be validated in a clinical setting in future studies.
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Affiliation(s)
- Yusuke Wada
- Drug Discovery Research, Astellas Pharma Inc., Tasukuba-shi, Ibaraki 3058585, Japan
| | - Masaki Abe
- Drug Discovery Research, Astellas Pharma Inc., Tasukuba-shi, Ibaraki 3058585, Japan
| | - Hiroshi Moritani
- Drug Discovery Research, Astellas Pharma Inc., Tasukuba-shi, Ibaraki 3058585, Japan
| | - Hikaru Mitori
- Drug Discovery Research, Astellas Pharma Inc., Tasukuba-shi, Ibaraki 3058585, Japan
| | - Mitsuhiro Kondo
- Drug Discovery Research, Astellas Pharma Inc., Tasukuba-shi, Ibaraki 3058585, Japan
| | - Keiko Tanaka-Amino
- Drug Discovery Research, Astellas Pharma Inc., Tasukuba-shi, Ibaraki 3058585, Japan
| | - Megumi Eguchi
- Drug Discovery Research, Astellas Pharma Inc., Tasukuba-shi, Ibaraki 3058585, Japan
| | - Akira Imasato
- Drug Discovery Research, Astellas Pharma Inc., Tasukuba-shi, Ibaraki 3058585, Japan
| | - Yutaka Inoki
- Drug Discovery Research, Astellas Pharma Inc., Tasukuba-shi, Ibaraki 3058585, Japan
| | - Hiroshi Kajiyama
- Department of Rheumatology and Applied Immunology, Faculty of Medicine, Saitama Medical University, Moroyama 3500495, Japan
| | - Toshihide Mimura
- Department of Rheumatology and Applied Immunology, Faculty of Medicine, Saitama Medical University, Moroyama 3500495, Japan
| | - Yuichi Tomura
- Drug Discovery Research, Astellas Pharma Inc., Tasukuba-shi, Ibaraki 3058585, Japan
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49
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Xu W, Ge Y, Liu Z, Gong R. Glycogen synthase kinase 3β dictates podocyte motility and focal adhesion turnover by modulating paxillin activity: implications for the protective effect of low-dose lithium in podocytopathy. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 184:2742-56. [PMID: 25239564 DOI: 10.1016/j.ajpath.2014.06.027] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 05/19/2014] [Accepted: 06/10/2014] [Indexed: 12/27/2022]
Abstract
Aberrant focal adhesion turnover is centrally involved in podocyte actin cytoskeleton disorganization and foot process effacement. The structural and dynamic integrity of focal adhesions is orchestrated by multiple cell signaling molecules, including glycogen synthase kinase 3β (GSK3β), a multitasking kinase lately identified as a mediator of kidney injury. However, the role of GSK3β in podocytopathy remains obscure. In doxorubicin (Adriamycin)-injured podocytes, lithium, a GSK3β inhibitor and neuroprotective mood stabilizer, obliterated the accelerated focal adhesion turnover, rectified podocyte hypermotility, and restored actin cytoskeleton integrity. Mechanistically, lithium counteracted the doxorubicin-elicited GSK3β overactivity and the hyperphosphorylation and overactivation of paxillin, a focal adhesion-associated adaptor protein. Moreover, forced expression of a dominant negative kinase dead mutant of GSK3β highly mimicked, whereas ectopic expression of a constitutively active GSK3β mutant abolished, the effect of lithium in doxorubicin-injured podocytes, suggesting that the effect of lithium is mediated, at least in part, through inhibition of GSK3β. Furthermore, paxillin interacted with GSK3β and served as its substrate. In mice with doxorubicin nephropathy, a single low dose of lithium ameliorated proteinuria and glomerulosclerosis. Consistently, lithium therapy abrogated GSK3β overactivity, blunted paxillin hyperphosphorylation, and reinstated actin cytoskeleton integrity in glomeruli associated with an early attenuation of podocyte foot process effacement. Thus, GSK3β-modulated focal adhesion dynamics might serve as a novel therapeutic target for podocytopathy.
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Affiliation(s)
- Weiwei Xu
- National Clinical Research Center of Kidney Disease, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China; Division of Kidney Disease and Hypertension, Department of Medicine, Rhode Island Hospital, Brown University School of Medicine, Providence, Rhode Island
| | - Yan Ge
- Division of Kidney Disease and Hypertension, Department of Medicine, Rhode Island Hospital, Brown University School of Medicine, Providence, Rhode Island
| | - Zhihong Liu
- National Clinical Research Center of Kidney Disease, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Rujun Gong
- Division of Kidney Disease and Hypertension, Department of Medicine, Rhode Island Hospital, Brown University School of Medicine, Providence, Rhode Island.
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Pudur S, Srivastava T, Sharma M, Sharma R, Tarima S, Dai H, McCarthy ET, Savin VJ. Serum glomerular albumin permeability activity: association with rapid progression to end-stage renal disease in focal segmental glomerulosclerosis. SPRINGERPLUS 2016; 5:432. [PMID: 27104120 PMCID: PMC4828406 DOI: 10.1186/s40064-016-2077-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 03/30/2016] [Indexed: 01/21/2023]
Abstract
BACKGROUND Focal segmental glomerulosclerosis (FSGS) is a major cause of renal failure. Sera of some FSGS patients increase glomerular albumin permeability (Palb) during in vitro testing and cause proteinuria in experimental animals. OBJECTIVES To determine whether permeability activity of FSGS serum (Palb activity) is associated with rate of progression to renal replacement therapy (RRT). DESIGN This is an observational study based on medical and demographic information and Palb activity testing. SETTING Studies were performed at Medical College of Wisconsin. PATIENTS Serum was submitted by patients' nephrologists for measurement of Palb activity. Each patient had had a biopsy diagnosis of FSGS, had reached ESRD and was on dialysis or had a functioning transplant. MEASUREMENTS Palb activity, clinical characteristics and time between biopsy diagnosis and RRT (T-RRT) were recorded for each patient. METHODS Palb activity was measured using established in vitro techniques. RESULTS Palb and T-RRT were inversely correlated. Neither Palb nor T-RRT varied with demographics or medications. Kaplan-Meier survival curves showed that patients with Palb ≥ 0.5 progressed to RRT more rapidly than others. LIMITATIONS Only patients who had reached RRT were included. Limited clinical information was available for each patient. Central verification of biopsy characteristics was not performed and detailed descriptions of renal histology were not available. CONCLUSIONS Palb activity is associated with the rate of progression to RRT in patients with FSGS. Additional observations will be needed to verify that Palb activity predicts prognosis and is useful in stratifying patients for clinical decision making or treatment trials.
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Affiliation(s)
| | - Tarak Srivastava
- Section of Nephrology, Children's Mercy Hospital, University of Missouri at Kansas City, 2401 Gillham Road, Kansas City, MO 64108 USA
| | - Mukut Sharma
- Kansas City Veterans Hospital, Kansas City, MO USA
| | - Ram Sharma
- Kansas City Veterans Hospital, Kansas City, MO USA
| | - Sergey Tarima
- Division of Biostatistics, Medical College of Wisconsin, Milwaukee, WI USA
| | - Hongying Dai
- Section of Nephrology, Children's Mercy Hospital, University of Missouri at Kansas City, 2401 Gillham Road, Kansas City, MO 64108 USA
| | - Ellen T McCarthy
- Kidney Institute, University of Kansas Medical Center, Kansas City, KS USA
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