title: Human urinary exosome proteome unveils its aerobic respiratory ability.
abstract: Exosomes are 40-100-nm vesicles released by most cell types after fusion of multivesicular endosomes with the plasma membrane. Exosomes, ubiquitary in body fluids including urines, contain proteins and RNA species specific of the tissue of origin. Exosomes from urine have been extensively studied as a promising reservoir for disease biomarkers. Here, we report the proteome analysis of urinary exosomes compared to urinoma, studied by Orbitrap mass spectrometry. A discovery approach was utilized on the sample. 3429 proteins were present, with minimal overlapping among exosome and urinoma. 959 proteins (28%) in exosome and 1478 proteins (43%) in urinoma were exclusively present in only one group. By cytoscape analysis, the biological process gene ontology was correlated to their probability (P ≤ 0.05) to be functional. This was never studied before and showed a significant clustering around metabolic functions, in particular to aerobic ATP production. Urinary exosomes carry out oxidative phosphorylation, being able to synthesize ATP and consume oxygen. A previously unsuspected function emerges for human urinary exosomes as bioactive vesicles that consume oxygen to aerobically synthesize ATP. Determination of normal human urine proteome can help generate the healthy urinary protein database for comparison, useful for various renal diseases.
  
  
  CONCLUSIONS
  The findings reported represent a significant advance in the understanding of the healthy human urinary proteome. The methodology utilized to analyze the collection of proteomic data allowed the assessment of the unique composition of urinary exosomes with respect to urinoma and to elucidate the presence in the former of molecular pathways previously unknown. The paper has the potential to impact its field of research, due to the biological relevance of the metabolic capacity of urinary exosomes, which may represent their important general feature.
authors: Division of Nephrology, Dialysis, and Transplantation and Laboratory on Pathophysiology of Uremia, Istituto Giannina Gaslini, Genoa, Italy.
authors: Maurizio
authors: M
authors: Bruschi
authors: Division of Nephrology, Dialysis, and Transplantation and Laboratory on Pathophysiology of Uremia, Istituto Giannina Gaslini, Genoa, Italy.
authors: Laura
authors: L
authors: Santucci
authors: Dipartimento di Farmacia, Laboratorio di Biochimica, Università di Genova, Genoa, Italy.
authors: Silvia
authors: S
authors: Ravera
authors: Division of Nephrology, Dialysis, and Transplantation and Laboratory on Pathophysiology of Uremia, Istituto Giannina Gaslini, Genoa, Italy.
authors: Giovanni
authors: G
authors: Candiano
authors: Laboratory of Mass Spectrometry - Core Facilities, Istituto Giannina Gaslini, Genova, Italy.
authors: Martina
authors: M
authors: Bartolucci
authors: Dipartimento di Farmacia, Laboratorio di Biochimica, Università di Genova, Genoa, Italy.
authors: Daniela
authors: D
authors: Calzia
authors: Laboratory of Mass Spectrometry - Core Facilities, Istituto Giannina Gaslini, Genova, Italy.
authors: Chiara
authors: C
authors: Lavarello
authors: Laboratory of Mass Spectrometry - Core Facilities, Istituto Giannina Gaslini, Genova, Italy.
authors: Elvira
authors: E
authors: Inglese
authors: Neonatal Intensive Care Unit, Istituto Giannina Gaslini, Genoa, Italy.
authors: Luca A
authors: LA
authors: Ramenghi
authors: Laboratory of Mass Spectrometry - Core Facilities, Istituto Giannina Gaslini, Genova, Italy.
authors: Andrea
authors: A
authors: Petretto
authors: Division of Nephrology, Dialysis, and Transplantation and Laboratory on Pathophysiology of Uremia, Istituto Giannina Gaslini, Genoa, Italy.
authors: Gian Marco
authors: GM
authors: Ghiggeri
authors: Dipartimento di Farmacia, Laboratorio di Biochimica, Università di Genova, Genoa, Italy. Electronic address: isabellapanfoli@gmail.com.
authors: Isabella
authors: I
authors: Panfoli
mesh_terms: D000328:Adult; D055354:Exosomes / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D020543:Proteome / Q000378:metabolism*; D053584:Urinoma / Q000652:urine*
chemical_list: D020543:Proteome
keywords: Exosomes; F(o)F(1)-ATP synthase; Mass spectrometry; Oxidative phosphorylation; Proteomics; Respiratory complexes; Urinoma