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Desideri S, Onions KL, Qiu Y, Ramnath RD, Butler MJ, Neal CR, King MLR, Salmon AE, Saleem MA, Welsh GI, Michel CC, Satchell SC, Salmon AHJ, Foster RR. A novel assay provides sensitive measurement of physiologically relevant changes in albumin permeability in isolated human and rodent glomeruli. Kidney Int 2018; 93:1086-1097. [PMID: 29433915 PMCID: PMC5912930 DOI: 10.1016/j.kint.2017.12.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 12/05/2017] [Accepted: 12/13/2017] [Indexed: 01/06/2023]
Abstract
Increased urinary albumin excretion is a key feature of glomerular disease but has limitations as a measure of glomerular permeability. Here we describe a novel assay to measure the apparent albumin permeability of single capillaries in glomeruli, isolated from perfused kidneys cleared of red blood cells. The rate of decline of the albumin concentration within the capillary lumen was quantified using confocal microscopy and used to calculate apparent permeability. The assay was extensively validated and provided robust, reproducible estimates of glomerular albumin permeability. These values were comparable with previous in vivo data, showing this assay could be applied to human as well as rodent glomeruli. To confirm this, we showed that targeted endothelial glycocalyx disruption resulted in increased glomerular albumin permeability in mice. Furthermore, incubation with plasma from patients with post-transplant recurrence of nephrotic syndrome increased albumin permeability in rat glomeruli compared to remission plasma. Finally, in glomeruli isolated from rats with early diabetes there was a significant increase in albumin permeability and loss of endothelial glycocalyx, both of which were ameliorated by angiopoietin-1. Thus, a glomerular permeability assay, producing physiologically relevant values with sufficient sensitivity to measure changes in glomerular permeability and independent of tubular function, was developed and validated. This assay significantly advances the ability to study biology and disease in rodent and human glomeruli.
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Affiliation(s)
- Sara Desideri
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Karen L Onions
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Yan Qiu
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Raina D Ramnath
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Matthew J Butler
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Christopher R Neal
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Matthew L R King
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Andrew E Salmon
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Moin A Saleem
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Gavin I Welsh
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | | | - Simon C Satchell
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Andrew H J Salmon
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK
| | - Rebecca R Foster
- Bristol Renal, Bristol Medical School, University of Bristol, Bristol, UK.
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α-asarone reduce proteinuria by restoring antioxidant enzymes activities and regulating necrosis factor κB signaling pathway in doxorubicin-induced nephrotic syndrome. Biomed Pharmacother 2018; 98:318-324. [DOI: 10.1016/j.biopha.2017.12.051] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 12/09/2017] [Accepted: 12/13/2017] [Indexed: 12/11/2022] Open
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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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