title: Hyaluronan fragments improve wound healing on in vitro cutaneous model through P2X7 purinoreceptor basal activation: role of molecular weight.
abstract: BACKGROUND
  hyaluronan biopolymer is used in dermatology but the underlying mechanism and the impact of its molecular weight have not yet been investigated in skin wound healing. The aim of our work was to study the role of HA molecular weight in the proliferative phase of wound healing and to understand how this physiological biopolymer acts to promote wound healing on a human keratinocyte in vitro model.
  
  
  RESULTS
  wound healing closure was evaluated using scratch test assay, cell proliferation by counting cell with haemocytometer, expression of CD44 and ZO-1 (protein present in tight junctions specific of epithelia) using flow cytometry, and P2X7 receptor activation on living using a cytoflurometric method. Our study showed that medium hyaluronan fragment (MMW-HA, between 100 and 300 kDa) induced a significant increase in wound closure, increased ZO-1 protein expression and induced a slight activation of P2X7 receptor, contrary to high (between 1000 and 1400 kDa) and low (between 5 and 20 kDa) molecular hyaluronan fragments that had no healing effects. Basal activation of P2X7 receptor is already known to stimulate cell proliferation and this activation in our model plays a pivotal role in MMW-HA-induced wound healing. Indeed, we showed that use of BBG, a specific inhibitor of P2X7 receptor, blocked completely the beneficial effects of MMW-HA on wound healing.
  
  
  CONCLUSIONS
  taken together, our results showed for the first time the relationship between P2X7 receptor and hyaluronan in wound healing, and that topical use of MMW-HA (fragment between 100 and 300 kDa) could represent a new therapeutic strategy to promote healing.
authors.affiliation: Chimie-Toxicologie Analytique et Cellulaire-EA 4463, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, Paris, France.
authors.forename: Kamelia
authors.initials: K
authors.lastname: Ghazi
authors.forename: Uriell
authors.initials: U
authors.lastname: Deng-Pichon
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Warnet
authors.forename: Patrice
authors.initials: P
authors.lastname: Rat
mesh_terms: D001481:Basal Metabolism / Q000187:drug effects*; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D006820:Hyaluronic Acid / Q000737:chemistry* / Q000494:pharmacology*; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008970:Molecular Weight; D058486:Receptors, Purinergic P2X7 / Q000378:metabolism*; D012867:Skin / Q000166:cytology*; D019108:Tight Junctions / Q000187:drug effects / Q000378:metabolism; D014945:Wound Healing / Q000187:drug effects*; D062826:Zonula Occludens-1 Protein / Q000378:metabolism
chemical_list: D018960:Hyaluronan Receptors; D058486:Receptors, Purinergic P2X7; C569042:TJP1 protein, human; D062826:Zonula Occludens-1 Protein; D006820:Hyaluronic Acid