title: Changes in epidermal hyaluronan metabolism following UVB irradiation.
abstract: BACKGROUND
  Hyaluronan (HA) plays a role in keratinocyte proliferation and differentiation, and have shown different biological activities depending on its molecular mass. While many studies have shown changes in the amount of HA after UVB irradiation, molecular mass change remains to be elucidated.
  
  
  OBJECTIVE
  To investigate the change in the molecular mass of HA after UVB irradiation in mouse epidermis.
  
  
  METHODS
  The mice were irradiated with a single dose of UVB (0.15J/cm(2)). The amount of HA was examined using HABP sandwich assay. The molecular mass distribution was estimated by Sephacryl S-1000 chromatography. Has and Hyal mRNA expressions were detected by real-time PCR.
  
  
  RESULTS
  On day 2 after UVB irradiation, both the amount of HA and the up-regulation of Has3 mRNA expression reached their maximum. The average HA molecular mass was about 1000 kDa, a level similar to that of the non-irradiated epidermis. On day 3, the average HA molecular mass drastically decreased to 100 kDa, while Hyal1, Hyal2, and Hyal3 mRNA expressions slightly increased. The amount of HA, however, remained high. On days 4 and 5, the amount of HA gradually decreased, but the molecular mass of HA remained low. A drastic reduction of the HA molecular mass after UVB irradiation was confirmed.
  
  
  CONCLUSIONS
  UVB irradiation elicits remarkable changes in the molecular mass of HA, as well as amount. These qualitative and quantitative changes of HA might play an important role in UVB-induced cell proliferation and differentiation. Further study will be required to resolve the mechanism of HA degradation in the epidermis.
authors.affiliation: Innovative Beauty Science Laboratory, Kanebo Cosmetics Inc., Odawara, Japan. tobiishi.megumi@kanebocos.co.jp
authors.forename: Megumi
authors.initials: M
authors.lastname: Tobiishi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Sayo
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yoshida
authors.forename: Ayumi
authors.initials: A
authors.lastname: Kusaka
authors.forename: Keigo
authors.initials: K
authors.lastname: Kawabata
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Sugiyama
authors.forename: Osamu
authors.initials: O
authors.lastname: Ishikawa
authors.forename: Shintaro
authors.initials: S
authors.lastname: Inoue
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D004817:Epidermis / Q000378:metabolism* / Q000528:radiation effects*; D058851:GPI-Linked Proteins / Q000096:biosynthesis; D014453:Glucuronosyltransferase / Q000096:biosynthesis; D018960:Hyaluronan Receptors / Q000096:biosynthesis; D000076002:Hyaluronan Synthases; D006820:Hyaluronic Acid / Q000378:metabolism*; D006821:Hyaluronoglucosaminidase / Q000096:biosynthesis; D015603:Keratinocytes / Q000166:cytology; D008297:Male; D051379:Mice; D008954:Models, Biological; D010539:Permeability; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D014466:Ultraviolet Rays
chemical_list: D058851:GPI-Linked Proteins; D018960:Hyaluronan Receptors; D006820:Hyaluronic Acid; D014453:Glucuronosyltransferase; C491356:Has3 protein, mouse; D000076002:Hyaluronan Synthases; C469220:Hyal1 protein, mouse; C469221:Hyal2 protein, mouse; D006821:Hyaluronoglucosaminidase