title: Differential regulation of hyaluronan metabolism in the epidermal and dermal compartments of human skin by UVB irradiation.
abstract: Hyaluronan (HA), a major component of the cutaneous extracellular-matrix, is involved in tissue repair. Human skin is exposed to and damaged by UVB-irradiation. Here, we investigate the regulation of HA metabolism in human skin during acute UVB-induced inflammation. Expression of HA synthesizing (HAS) and degrading enzymes hyaluronidase (HYAL) as evaluated by quantitative reverse transcribed PCR in response to UVB differed when fibroblasts and HaCaT-keratinocytes, representative cell types in dermis and epidermis, respectively, were compared. Both demonstrated temporally different expression patterns of these genes 3- and 24-hours post-irradiation. This resulted 24-hours post-irradiation in an increase in HAS gene expression in both fibroblasts and HaCaT-keratinocytes, and an increase in HYAL expression only in fibroblasts. HA-production as analyzed by the HA content of conditioned medium was reduced in HaCaT and fibroblast cultures 3-hours post-irradiation, whereas HA increased in HaCaT-cultures 24-hours post-irradiation but remained suppressed in fibroblasts-cultures. Consistently, immunohistochemical staining for HA in human skin 24-hours post-irradiation demonstrated an increased epidermal HA, but a decrease in the dermal compartment. Moreover, analysis of the HA content of dermal microdialysis-fluid revealed increased accumulation of HA degradation products 24-hours post-irradiation. These data demonstrate that there is a complex temporal and spatial regulation of HA-metabolism in skin in response to UVB irradiation.
authors.affiliation: Department of Dermatology, Venerology and Allergology, Leipzig University Medical Center, Leipzig, Germany. marco.averbeck@medizin.uni-leipzig.de
authors.forename: Marco
authors.initials: M
authors.lastname: Averbeck
authors.forename: Carl A
authors.initials: CA
authors.lastname: Gebhardt
authors.forename: Susanne
authors.initials: S
authors.lastname: Voigt
authors.forename: Simone
authors.initials: S
authors.lastname: Beilharz
authors.forename: Ulf
authors.initials: U
authors.lastname: Anderegg
authors.forename: Christian C
authors.initials: CC
authors.lastname: Termeer
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Sleeman
authors.forename: Jan C
authors.initials: JC
authors.lastname: Simon
mesh_terms: D002478:Cells, Cultured; D020405:Dermis / Q000378:metabolism* / Q000528:radiation effects; D004817:Epidermis / Q000378:metabolism* / Q000528:radiation effects; D005347:Fibroblasts / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D006820:Hyaluronic Acid / Q000378:metabolism*; D015603:Keratinocytes / Q000378:metabolism; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D012867:Skin / Q000166:cytology / Q000378:metabolism* / Q000528:radiation effects*; D012879:Skin Physiological Phenomena; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D012333:RNA, Messenger; D006820:Hyaluronic Acid