title: Urinary extracellular vesicles as reservoirs of altered proteins during the pathogenesis of polycystic kidney disease.
abstract: OBJECTIVE
  Recent findings indicate that urinary extracellular vesicles (EVs) might reflect the pathophysiological state of urinary system; and that EVs-induced ciliary signaling is a possible mechanism of intercellular communication within the tract. Here, we aimed to analyze the protein expression of urinary EVs during autosomal dominant polycystic kidney disease (ADPKD).
  
  
  METHODS
  EVs were isolated from pooled urine samples of healthy control and ADPKD patients at two different stages of the disease and under tolvaptan treatment using the double-cushion ultracentrifugation method. Proteins were identified and quantified by iTRAQ and multidimensional protein identification technology (MudPIT)-based quantitative proteomics.
  
  
  RESULTS
  Quantitative analyses identified 83 differentially expressed EV proteins. Many of these have apical membrane origin and are involved in signal transduction pathways of primary cilia, Ca(2+) -activated signaling, cell-cycle regulation, and cell differentiation.
  
  
  CONCLUSIONS
  The reduced AQP-2 and the increased APO-A1 levels observed in all ADPKD-affected groups may reflects the impaired renal concentrating capability of these patients and correlated with estimated glomerular filtration rate decline. The levels of some upregulated proteins involved in Ca(2+) -activated signaling declined upon tolvaptan treatment. The results obtained suggest that the quantitative proteomics of urinary EVs might be useful to monitor proteins difficult to access noninvasively, and thus advance our understanding of urinary tract physiology and pathology.
authors.affiliation: Mass Spectrometry and Proteomics, Institute of Biosciences and BioResources, National Research Council of Italy, Naples, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Pocsfalvi
authors.affiliation: Mass Spectrometry and Proteomics, Institute of Biosciences and BioResources, National Research Council of Italy, Naples, Italy.
authors.forename: Delfin A A
authors.initials: DA
authors.lastname: Raj
authors.affiliation: Mass Spectrometry and Proteomics, Institute of Biosciences and BioResources, National Research Council of Italy, Naples, Italy.
authors.forename: Immacolata
authors.initials: I
authors.lastname: Fiume
authors.affiliation: Mass Spectrometry and Proteomics, Institute of Biosciences and BioResources, National Research Council of Italy, Naples, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Vilasi
authors.affiliation: Division of Nephrology, Department of Cardio-Vascular Sciences, Second University of Naples, Naples, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Trepiccione
authors.affiliation: Division of Nephrology, Department of Cardio-Vascular Sciences, Second University of Naples, Naples, Italy.
authors.forename: Giovambattista
authors.initials: G
authors.lastname: Capasso
mesh_terms: D000328:Adult; D000368:Aged; D065092:Antidiuretic Hormone Receptor Antagonists / Q000494:pharmacology / Q000627:therapeutic use; D051399:Aquaporin 2 / Q000652:urine; D001552:Benzazepines / Q000494:pharmacology / Q000627:therapeutic use; D015415:Biomarkers / Q000652:urine; D002135:Calcium-Binding Proteins / Q000652:urine; D016022:Case-Control Studies; D000067128:Extracellular Vesicles / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D007690:Polycystic Kidney Diseases / Q000188:drug therapy / Q000652:urine*; D020543:Proteome / Q000378:metabolism; D000077602:Tolvaptan; D060449:Wnt Signaling Pathway; D055815:Young Adult
chemical_list: C496023:AQP2 protein, human; D065092:Antidiuretic Hormone Receptor Antagonists; D051399:Aquaporin 2; D001552:Benzazepines; D015415:Biomarkers; D002135:Calcium-Binding Proteins; D020543:Proteome; D000077602:Tolvaptan
keywords: Ciliary signaling pathway; Extracellular vesicles; Kidney physiology; Polycystic kidney disease; Quantitative proteomics