title: Riboflavin and ultraviolet light treatment potentiates vasodilator-stimulated phosphoprotein Ser-239 phosphorylation in platelet concentrates during storage.
abstract: BACKGROUND
  Pathogen reduction technologies (PRTs) were developed to improve the safety of platelet concentrates (PCs) for transfusion purposes; however, several studies report a negative impact on the in vitro and in vivo platelet (PLT) quality. Therefore, analyses of the underlying molecular processes triggered by PRT treatments are necessary to understand their effects on PLT function.
  
  
  METHODS
  In two separate two-arm studies PCs prepared in plasma for storage either by the leukoreduced buffy coat (BC-PCs) or by the leukoreduced apheresis (AP-PCs) method were treated with or without riboflavin and ultraviolet (UV) light (Mirasol; 6.24 J/mL; 265-375 nm). Samples were drawn after treatment and after 1, 4, and 6 days of storage with subsequent analyses performed using in vitro measurements for PLT quality monitoring. Semiquantitative proteomic studies identified proteins that changed in band intensities in response to treatment or storage. Protein validation and subsequent biochemical studies were carried out by immunoblot analyses.
  
  
  RESULTS
  The proteomic results identified changes mainly of proteins associated with the structure and regulation of the cytoskeleton. Focusing on the vasodilator-stimulated phosphoprotein (VASP) in AP-PCs revealed a storage-dependent, but treatment-independent, delocalization and a strong treatment-dependent phosphorylation at Ser-239 that was also present, but to a much lesser degree in BC-PCs. This modification correlated exponentially with PLT activation as determined by P-selectin expression.
  
  
  CONCLUSIONS
  Treatment of PCs with Mirasol leads to the amplification of VASP Ser-239 phosphorylation, which is linked to actin dynamics and regulation of integrin α(IIb) β(3) activation. This change offers one explanation for Mirasol's impact on PLT in vitro quality measures. The Ser-239 phosphorylation level of VASP might be a useful protein marker for riboflavin and UV light-mediated PLT compromise.
authors.affiliation: Canadian Blood Services, Centre for Blood Research and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Schubert
authors.forename: Brankica
authors.initials: B
authors.lastname: Culibrk
authors.forename: Danielle
authors.initials: D
authors.lastname: Coupland
authors.forename: Ken
authors.initials: K
authors.lastname: Scammell
authors.forename: Maria
authors.initials: M
authors.lastname: Gyongyossy-Issa
authors.forename: Dana V
authors.initials: DV
authors.lastname: Devine
mesh_terms: D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D001793:Blood Preservation / Q000009:adverse effects / Q000379:methods; D015815:Cell Adhesion Molecules / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D008421:Materials Management, Hospital; D008840:Microfilament Proteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D015539:Platelet Activation / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D010976:Platelet Count; D017713:Platelet Transfusion; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D040901:Proteomics; D011786:Quality Control; D012256:Riboflavin / Q000009:adverse effects / Q000494:pharmacology*; D012694:Serine / Q000737:chemistry / Q000378:metabolism; D014466:Ultraviolet Rays / Q000009:adverse effects; D015854:Up-Regulation / Q000187:drug effects / Q000528:radiation effects; D000098662:Vasodilator-Stimulated Phosphoprotein
chemical_list: D015415:Biomarkers; D015815:Cell Adhesion Molecules; D008840:Microfilament Proteins; D010750:Phosphoproteins; D000098662:Vasodilator-Stimulated Phosphoprotein; D012694:Serine; D017346:Protein Serine-Threonine Kinases; D012256:Riboflavin