title: Endothelial progenitor cell-derived extracellular vesicles protect from complement-mediated mesangial injury in experimental anti-Thy1.1 glomerulonephritis.
abstract: BACKGROUND
  Endothelial progenitor cells (EPCs) are known to induce tissue repair by paracrine mechanisms including the release of growth factors and extracellular vesicles (EVs), nanoparticles able to carry proteins and genetic information to target cells. The aim of this study was to evaluate whether EVs derived from EPCs may protect from complement-mediated mesangial injury in experimental anti-Thy1.1 glomerulonephritis.
  
  
  METHODS
  EVs were isolated by serial ultracentrifugation from supernatants of cultured human EPCs and characterized for their protein and RNA content. In vivo, EVs were injected i.v. in the experimental rat model of mesangiolytic anti-Thy1.1 glomerulonephritis evaluating renal function, proteinuria, complement activity and histological lesions. In vitro, the biological effects of EPC-derived EVs were studied in cultured rat mesangial cells incubated with anti-Thy1.1 antibody and rat or human serum as complement source.
  
  
  RESULTS
  After i.v. injection in Thy1.1-treated rats, EVs localized within injured glomeruli and inhibited mesangial cell activation, leucocyte infiltration and apoptosis, decreased proteinuria, increased serum complement haemolytic activity (CH50) and ameliorated renal function. EV treatment decreased intraglomerular deposition of the membrane attack complex (MAC or C5b-9) and expression of smooth muscle cell actin and preserved the endothelial antigen RECA-1 and the podocyte marker synaptopodin. The protective effect of EVs was significantly reduced by pre-treatment with a high dose of RNase (1 U/mL), suggesting a key role for EV-carried RNAs in these mechanisms. Indeed, EPC-derived EVs contained different mRNAs coding for several anti-apoptotic molecules and for the complement inhibitors Factor H, CD55 and CD59 and the related proteins. The in vitro experiments aimed to investigate the mechanisms of EV protection indicated that EVs transferred to mesangial cell mRNAs coding for Factor H, CD55 and CD59 and inhibited anti-Thy1.1 antibody/complement-induced apoptosis and C5b-9/C3 mesangial cell deposition.
  
  
  CONCLUSIONS
  EVs derived from EPCs exert a protective effect in Thy1.1 glomerulonephritis by inhibition of antibody- and complement-mediated injury of mesangial cells.
authors.affiliation: Nephrology, Dialysis and Kidney Transplantation Unit and Center for Experimental Medical Research (CeRMS), Department of Medical Sciences, University of Torino, Torino, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Cantaluppi
authors.affiliation: Nephrology, Dialysis and Kidney Transplantation Unit and Center for Experimental Medical Research (CeRMS), Department of Medical Sciences, University of Torino, Torino, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Medica
authors.affiliation: Department of Pharmacology, University of Pisa, Pisa, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Mannari
authors.affiliation: Department of Pharmacology, University of Pisa, Pisa, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Stiaccini
authors.affiliation: Nephrology, Dialysis and Kidney Transplantation Unit and Center for Experimental Medical Research (CeRMS), Department of Medical Sciences, University of Torino, Torino, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Figliolini
authors.affiliation: Nephrology, Dialysis and Kidney Transplantation Unit and Center for Experimental Medical Research (CeRMS), Department of Medical Sciences, University of Torino, Torino, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Dellepiane
authors.affiliation: Nephrology, Dialysis and Kidney Transplantation Unit and Center for Experimental Medical Research (CeRMS), Department of Medical Sciences, University of Torino, Torino, Italy.
authors.forename: Alessandro Domenico
authors.initials: AD
authors.lastname: Quercia
authors.affiliation: Nephrology and Dialysis Unit, Ospedale Versilia, Camaiore, LU, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Migliori
authors.affiliation: Nephrology and Dialysis Unit, Ospedale Versilia, Camaiore, LU, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Panichi
authors.affiliation: Department of Pharmacology, University of Pisa, Pisa, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Giovannini
authors.affiliation: Nephrology, Dialysis and Kidney Transplantation Unit and Center for Experimental Medical Research (CeRMS), Department of Medical Sciences, University of Torino, Torino, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Bruno
authors.affiliation: EMEALA Medical Board, Fresenius Medical Care, Bad Homburg, Germany.
authors.forename: Ciro
authors.initials: C
authors.lastname: Tetta
authors.affiliation: Nephrology, Dialysis and Kidney Transplantation Unit and Center for Experimental Medical Research (CeRMS), Department of Medical Sciences, University of Torino, Torino, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Biancone
authors.affiliation: Nephrology, Dialysis and Kidney Transplantation Unit and Center for Experimental Medical Research (CeRMS), Department of Medical Sciences, University of Torino, Torino, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Camussi
mesh_terms: D000818:Animals; D017209:Apoptosis; D002478:Cells, Cultured; D015938:Complement Membrane Attack Complex / Q000276:immunology*; D066026:Endothelial Progenitor Cells / Q000276:immunology*; D000067128:Extracellular Vesicles / Q000276:immunology*; D005260:Female; D005455:Fluorescent Antibody Technique; D005920:Glomerular Mesangium / Q000276:immunology* / Q000293:injuries / Q000473:pathology; D005921:Glomerulonephritis / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007518:Isoantibodies / Q000276:immunology*; D011507:Proteinuria / Q000276:immunology*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D015938:Complement Membrane Attack Complex; D007518:Isoantibodies; D012333:RNA, Messenger; C035678:anti-Thy antibody
keywords: apoptosis; complement inhibitors; endothelial progenitor cells; extracellular vesicles; glomerulonephritis