title: Expression of vitamin D receptor in cultured human keratinocytes and fibroblasts is not altered by corticosteroids.
abstract: Topical vitamin D3 therapy is one of the mainstays of psoriasis treatment. However, the effectiveness of combination therapy with topical vitamin D3 and corticosteroids is still controversial. It has been reported that topical vitamin D3 treatment following topical corticosteroids is less effective than that without preceding corticosteroid treatment. We hypothesized that vitamin D receptor (VDR) in the skin is down-regulated by topical corticosteroids. To obtain support for this hypothesis, we determined VDR protein levels in cultured keratinocytes and fibroblasts after corticosteroid treatment. VDR levels were quantified by Western blot analysis with a Fluorolmager. Keratinocytes and fibroblasts were obtained from four psoriasis patients and four normal controls. VDR levels were altered in neither normal nor psoriatic keratinocytes by 2-day incubation with dexamethasone (1x10(-9)-1x10(-6) M) or clobetasol propionate (1x10(-9)-1x10(-6) M). Similarly, VDR levels in normal and psoriatic fibroblasts were not affected by 2-day incubation with dexamethasone (1x10(-6) M). These findings suggest that down-regulation of VDR by topical corticosteroids in keratinocytes and fibroblasts of psoriasis is unlikely.
authors.affiliation: Department of Dermatology, Ehime University School of Medicine, Shigenobucho, Onsengun, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Midorikawa
authors.forename: K
authors.initials: K
authors.lastname: Sayama
authors.forename: Y
authors.initials: Y
authors.lastname: Shirakata
authors.forename: Y
authors.initials: Y
authors.lastname: Hanakawa
authors.forename: L
authors.initials: L
authors.lastname: Sun
authors.forename: K
authors.initials: K
authors.lastname: Hashimoto
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000368:Aged; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D015153:Blotting, Western; D002478:Cells, Cultured; D002990:Clobetasol / Q000031:analogs & derivatives* / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology*; D015536:Down-Regulation / Q000187:drug effects; D005260:Female; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D005938:Glucocorticoids; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011565:Psoriasis / Q000378:metabolism / Q000473:pathology; D018167:Receptors, Calcitriol / Q000096:biosynthesis*; D012867:Skin / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D005938:Glucocorticoids; D018167:Receptors, Calcitriol; D003907:Dexamethasone; D002990:Clobetasol