title: Platelet-rich plasma stimulates dermal microvascular endothelial cells and adipose derived stem cells after external radiation.
abstract: BACKGROUND
  Platelet-rich plasma (PRP) products are currently suggested in the treatment of chronic wounds due to possible pro-angiogenic effects. Microvascular compromise represents the major component in radiogenic wound healing complications. The effects of PRP on irradiated cells of the cutaneous wound healing process are still poorly understood.
  
  
  METHODS
  Human dermal microvascular endothelial cells (HDMEC) and human adipose derived stem cells (hASC) were cultured and irradiated with doses of 2 to 12 Gy. PRP was activated, characterized and added to the incubation media in different concentrations after external radiation. Cell count was determined 48 h after radiation using a semi-automated cell counting system. Levels of interleukin-6 (IL-6), basic fibroblast growth factor (bFGF) and soluble intercellular adhesion molecule-1 (sICAM-1) in the supernatants of HDMEC and hASC co-cultures were determined by enzyme-linked immunosorbent assay (ELISA). Non-irradiated hASC and HDMEC served as controls.
  
  
  RESULTS
  The employed PRP preparations were characterized and contained platelet derived growth factor (PDGF-AB), vascular endothelial growth factor (VEGF), bFGF and high levels of sICAM-1. Addition of PRP to irradiated cultures of HDMEC and hASC prevented profound radiation-induced decline in cell numbers. 10% PRP restored cell numbers to levels of untreated, non-irradiated cultures. Basic FGF expression was decreased significantly in hASC monocultures treated with 10% PRP without external radiation and after irradiation with 6 and 12 Gy. These inhibitory effects of PRP were also observed in HDMEC. In contrast, co-cultures of HDMEC-ASC showed a dose-dependent increase in bFGF expression when treated with 5 or 10% PRP. Doses of 6 and 12 Gy increased IL-6 expression in cultures stimulated with 5% PRP.
  
  
  CONCLUSIONS
  Use of PRP in co-cultures of hASC and HDMEC restores proliferative defects caused by external radiation probably by induction of bFGF. Under irradiated conditions, PRP might induce pro-inflammatory stimuli which could be beneficial in treatment of chronic wounds where healing processes are defective. Combined use of hASC and PRP products might be helpful in the treatment of radiogenic wounds.
authors.affiliation: Department of Otorhinolaryngology, Division of Facial Plastic Surgery, University of Regensburg, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Haubner
authors.affiliation: Department of Otorhinolaryngology, Division of Facial Plastic Surgery, University of Regensburg, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Muschter
authors.affiliation: Department of Otorhinolaryngology, Division of Facial Plastic Surgery, University of Regensburg, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Schuster
authors.affiliation: Department of Radiotherapy, University of Regensburg, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Pohl
authors.affiliation: Department of Clinical Chemistry and Laboratory Medicine, University of Regensburg, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Ahrens
authors.affiliation: Center for Plastic, Aesthetic, Hand & Reconstructive Surgery, University Hospital Regensburg, Regensburg, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Prantl
authors.affiliation: Department of Otorhinolaryngology, Division of Facial Plastic Surgery, University of Regensburg, Germany.
authors.forename: H G
authors.initials: HG
authors.lastname: Gassner
mesh_terms: D000273:Adipose Tissue / Q000166:cytology / Q000502:physiology*; D020405:Dermis / Q000098:blood supply* / Q000528:radiation effects; D042783:Endothelial Cells / Q000502:physiology* / Q000528:radiation effects; D006801:Humans; D055806:Microvessels / Q000502:physiology* / Q000528:radiation effects; D053657:Platelet-Rich Plasma; D013234:Stem Cells / Q000502:physiology* / Q000528:radiation effects; D014945:Wound Healing / Q000502:physiology* / Q000528:radiation effects
keywords: Microvascular endothelial cells; adhesion molecules; cytokines; endothelial dysfunction; growth factors; human adipose-derived stem cells; radiation therapy