title: Proteomic analysis of podocyte exosome-enriched fraction from normal human urine.
abstract: Urine results from a coordinated activity of glomerular and tubular compartments of the kidney. As a footprint of these cellular functional processes, urinary exosomes, and 40-80 nm membrane vesicles released after fusion with the plasma membrane into the extracellular environment by renal epithelial cells, are a source for identification of proteins and investigation of their role in the kidney. The aim of the present study was the identification of podocyte exosome proteins based on urine immunoabsorption using podocyte-specific CR1-immunocoated beads followed by proteomic analysis using LC MS/MS techniques. This methodology allowed the identification of 1195 proteins. By using a bioinformatic approach, 27 brain-expressed proteins were identified, in which 14 out of them were newly demonstrated to be expressed in the kidney at a mRNA level, and, one of them, the COMT protein, was demonstrated to be expressed in podocytes at a protein level. These results, attesting the reliability of the methodology to identify podocyte proteins, need now to be completed by further experiments to analyze more precisely their biological function(s) in the podocytes.
authors: Institute of Clinical Pathology, Geneva University Hospitals, Geneva CH-1211, Switzerland. marco.prunotto@gmail.com
authors: Marco
authors: M
authors: Prunotto
authors: Annarita
authors: A
authors: Farina
authors: Lydie
authors: L
authors: Lane
authors: Agnès
authors: A
authors: Pernin
authors: Jürg
authors: J
authors: Schifferli
authors: Denis F
authors: DF
authors: Hochstrasser
authors: Pierre
authors: P
authors: Lescuyer
authors: Solange
authors: S
authors: Moll
mesh_terms: D055354:Exosomes / Q000378:metabolism*; D005260:Female; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D008875:Middle Aged; D050199:Podocytes / Q000378:metabolism*; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D014556:Urine
chemical_list: D020543:Proteome