title: Proteomic analysis of the kidney filtration barrier--Problems and perspectives.
abstract: Diseases of the glomerular filter of the kidney are a leading cause of end-stage renal failure. The kidney filter is localized within the renal glomeruli, small microvascular units that are responsible for ultrafiltration of about 180 liters of primary urine every day. The renal filter consists of three layers, fenestrated endothelial cells, glomerular basement membrane, and the podocytes, terminally differentiated, arborized epithelial cells. This review demonstrates the use of proteomics to generate insights into the regulation of the renal filtration barrier at a molecular level. The advantages and disadvantages of different glomerular purification methods are examined, and the technical limitations that have been significantly improved by in silico or biochemical approaches are presented. We also comment on phosphoproteomic studies that have generated considerable molecular-level understanding of the physiological regulation of the kidney filter. Lastly, we conclude with an analysis of urinary exosomes as a potential filter-derived resource for the noninvasive discovery of glomerular disease mechanisms.
authors.affiliation: Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.|Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.|Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany.
authors.forename: Markus M
authors.initials: MM
authors.lastname: Rinschen
authors.affiliation: Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.|Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.|Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Benzing
authors.affiliation: Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Kavee
authors.initials: K
authors.lastname: Limbutara
authors.affiliation: Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Trairak
authors.initials: T
authors.lastname: Pisitkun
mesh_terms: D053000:Analytic Sample Preparation Methods; D000818:Animals; D055354:Exosomes / Q000378:metabolism; D060730:Glomerular Filtration Barrier / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D011499:Protein Processing, Post-Translational; D040901:Proteomics / Q000379:methods*
keywords: Glomeruli; Kidney; Phosphorylation; Physiology; Sample preparation; Signaling