title: Interleukin-4 suppresses the enhancement of ceramide synthesis and cutaneous permeability barrier functions induced by tumor necrosis factor-alpha and interferon-gamma in human epidermis.
abstract: Ceramide is an integral part of the extracellular lipid bilayer of the stratum corneum (SC) that forms the permeability barrier of the skin. The production of SC ceramides is catalyzed by sphingomyelinase (SMase) and glucocerebrosidase (GCase). Acid-ceramidase (acid-CDase) catalyzes the hydrolysis of ceramide in the SC. We examined the effects of T helper (Th)1 and Th2 cytokines on levels of transcripts of genes for acid-CDase, acid-SMase, and GCase, on levels of ceramide, and on the extent of transepidermal water loss (TEWL) in the human epidermis in an effort to determine whether these cytokines affect the permeability barrier functions. Levels of transcripts for acid-SMase and GCase and the amount of ceramide in human epidermal sheets were enhanced by tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma and these effects were inhibited in the presence of interleukin (IL)-4. In epidermal keratinocytes cultured under submerged conditions, however, no similar inhibitory effects of IL-4 were observed. Consistent with these results, TEWL was suppressed by TNF-alpha and IFN-gamma, and these effects were also inhibited by IL-4. The balance between Th1 and Th2 might affect the construction and/or the repair of the epidermal permeability barrier via regulation of the production of ceramide.
authors.affiliation: Department of Anatomy, Biology and Medicine (Dermatology), Faculty of Medicine, Oita University, Oita, Japan. HATANO@med.oita-u.ac.jp
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Hatano
authors.forename: Hiroto
authors.initials: H
authors.lastname: Terashi
authors.forename: Shoko
authors.initials: S
authors.lastname: Arakawa
authors.forename: Kazumoto
authors.initials: K
authors.lastname: Katagiri
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D002518:Ceramides / Q000096:biosynthesis*; D004347:Drug Interactions; D004817:Epidermis / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D002517:Galactosylgalactosylglucosylceramidase / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects / Q000276:immunology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000276:immunology; D005962:Glucosylceramidase / Q000235:genetics; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D015847:Interleukin-4 / Q000494:pharmacology*; D009924:Organ Culture Techniques; D010539:Permeability / Q000187:drug effects; D012333:RNA, Messenger / Q000032:analysis; D013108:Sphingomyelin Phosphodiesterase / Q000235:genetics; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D014867:Water / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D002518:Ceramides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D014867:Water; D015847:Interleukin-4; D007371:Interferon-gamma; C112980:acid sphingomyelinase-1; D013108:Sphingomyelin Phosphodiesterase; D005962:Glucosylceramidase; D002517:Galactosylgalactosylglucosylceramidase