title: In vitro assessment of IL-4- or IL-13-mediated changes in the structural components of keratinocytes in mice and humans.
abstract: T helper type 2 (Th2) cytokines, IL-4 and IL-13, attenuate the expression of genes that regulate epidermal cellular structures and the barrier function at the terminal stage of keratinocyte differentiation. However, whether these Th2 cytokines act at earlier stages remains unknown. We investigated the roles of cytokines in expression levels of mRNAs and/or proteins in primary mouse keratinocytes and human keratinocyte HaCaT cells at earlier stages. We showed that IL-4 downregulated the expression levels of Krt1, Krt10, Dsg1, and Dsc1 via IL-4Rα- and signal transducer and activator of transcription factor 6 (STAT6)-dependent mechanisms in differentiating mouse keratinocytes at early stages. As the expression levels of keratin-1 and -10 in the keratinocytes transiently expressing an active form of STAT6 were not downregulated, STAT6 and other IL-4-induced molecules may synergistically regulate this expression. The restoration of the downregulated expression levels of Krt1 and Krt10 induced by IL-4 with the MEK (mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase kinase) inhibitor U0126 indicated the involvement of the p44/42 MAPK signaling pathway in the attenuated expression. IL-13 also downregulated the expression of the four genes. Furthermore, IL-4 or IL-13 caused the downregulation of these genes in HaCaT cells and promoted the fragmentation of cell sheets with mechanical stress. Our results showed that IL-4 or IL-13 acted on differentiating keratinocytes in vitro at early stages to attenuate the gene expression.
authors.affiliation: Department of Microbiology and Immunology, Tokyo Women's Medical University, Tokyo, Japan. Electronic address: momorim@research.twmu.ac.jp.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Omori-Miyake
authors.affiliation: Laboratory of Medical Genomics, Department of Human Genome Research, Kazusa DNA Research Institute, Kisarazu, Chiba, Japan.
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Yamashita
authors.affiliation: Department of Dermatology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Tsunemi
authors.affiliation: Department of Dermatology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kawashima
authors.affiliation: Department of Microbiology and Immunology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Yagi
mesh_terms: D000818:Animals; D002460:Cell Line; D003876:Dermatitis, Atopic / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D051187:Desmocollins / Q000235:genetics / Q000378:metabolism; D051183:Desmoglein 1 / Q000235:genetics / Q000378:metabolism; D000078404:Epidermal Cells; D004817:Epidermis / Q000502:physiology; D006801:Humans; D018793:Interleukin-13 / Q000378:metabolism*; D007377:Interleukin-3 / Q000378:metabolism*; D015847:Interleukin-4 / Q000378:metabolism*; D053556:Keratin-1 / Q000235:genetics / Q000378:metabolism; D053550:Keratin-10 / Q000235:genetics / Q000378:metabolism; D015603:Keratinocytes / Q000166:cytology / Q000502:physiology*; D053564:Keratins, Hair-Specific / Q000235:genetics / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000502:physiology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D061251:Primary Cell Culture; D018418:Th2 Cells / Q000166:cytology / Q000502:physiology*
chemical_list: C081560:DSC1 protein, human; C495297:DSG1 protein, human; D051187:Desmocollins; D051183:Desmoglein 1; C489910:Dsc1 protein, mouse; C495299:Dsg1a protein, mouse; C578095:IL13 protein, human; C508598:IL4 protein, human; D018793:Interleukin-13; D007377:Interleukin-3; C491616:KRT1 protein, human; C507493:KRT10 protein, human; D053556:Keratin-1; D053564:Keratins, Hair-Specific; C507530:Krt1 protein, mouse; C507491:Krt10 protein, mouse; D008562:Membrane Glycoproteins; D053550:Keratin-10; D015847:Interleukin-4