title: Upregulation of histidine decarboxylase mRNA expression in scleroderma skin.
abstract: The involvement of histamine in the pathogenesis of systemic sclerosis (SSc) has been suggested. Possible involvement of histamine and histidine decarboxylase (HDC), the synthesizing enzyme for histamine, in the formation of the skin abnormalities in SSc was studied. Skin histamine concentrations in SSc were significantly lower than in normal controls (P < 0.02). In situ hybridization with an HDC probe revealed that the expression of the HDC gene in SSc was greater than in normal controls. The number of cells and the mean grain number per cell expressing HDC mRNA were both significantly greater in SSc than in normal controls (both P < 0.01). These results show a reduction in histamine concentration and an elevated HDC gene expression in SSc skin, indicating an increase in both histamine release and HDC gene expression. The upregulation of histamine turnover appears to be involved in the formation of the skin abnormalities of SSc.
authors.affiliation: Department of Dermatology, Dokkyo University School of Medicine, Mibu, Tochigi, Japan. tohtsuka@dokkyomed.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Ohtsuka
authors.forename: H
authors.initials: H
authors.lastname: Ohtake
authors.forename: S
authors.initials: S
authors.lastname: Matsuzaki
authors.forename: K
authors.initials: K
authors.lastname: Ichimura
authors.forename: A
authors.initials: A
authors.lastname: Ichikawa
authors.forename: A
authors.initials: A
authors.lastname: Yamakage
authors.forename: S
authors.initials: S
authors.lastname: Yamazaki
mesh_terms: D000328:Adult; D015152:Blotting, Northern; D005260:Female; D015870:Gene Expression; D006632:Histamine / Q000378:metabolism; D006640:Histidine Decarboxylase / Q000235:genetics*; D006801:Humans; D017403:In Situ Hybridization; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D012333:RNA, Messenger / Q000378:metabolism*; D012595:Scleroderma, Systemic / Q000378:metabolism* / Q000503:physiopathology; D012867:Skin / Q000378:metabolism*; D014018:Tissue Distribution; D015854:Up-Regulation
chemical_list: D012333:RNA, Messenger; D006632:Histamine; D006640:Histidine Decarboxylase