title: Inhibition of transcription factor specificity protein 1 alters the gene expression profile of keratinocytes leading to upregulation of kallikrein-related peptidases and thymic stromal lymphopoietin.
abstract: Transcription factor specificity protein 1 (Sp1) is involved in diverse cellular functions. We recently found that Sp1 was significantly decreased in skin biopsy samples obtained from patients with atopic dermatitis (AD) and had an even greater reduction in AD patients with a history of eczema herpeticum. In the current study, we sought to better understand the role of Sp1 in skin biological processes by using a small-interfering RNA (siRNA) technique to knock down Sp1 gene expression in normal human keratinocytes (NHKs) and investigated the genome-wide gene expression profiling of Sp1-silenced NHKs. The gene arrays revealed that 53 genes had greater than 3-fold changes in the expression in Sp1-silenced NHKs as compared with scrambled siRNA-silenced cells. Strikingly, six kallikrein (KLK)-related peptidase genes, namely KLK5, KLK6, KLK7, KLK8, KLK10, and KLK12, were upregulated in NHKs following Sp1 silencing. Functionally, protease activity was significantly enhanced in Sp1-silenced keratinocytes as compared with scrambled siRNA-silenced keratinocytes. Moreover, thymic stromal lymphopoietin (TSLP), an epithelial-derived T(H)2-promoting cytokine, was induced in Sp1-silenced keratinocytes because of elevated KLK activity. These results indicate that Sp1 expression deficiency leads to abnormally increased KLK protease activity in keratinocytes and may contribute to T(H)2 immune responses in the skin by inducing TSLP.
authors.affiliation: Department of Pediatrics, National Jewish Health, Denver, Colorado 80206, USA.
authors.forename: Lianghua
authors.initials: L
authors.lastname: Bin
authors.forename: Byung E
authors.initials: BE
authors.lastname: Kim
authors.forename: Clifton F
authors.initials: CF
authors.lastname: Hall
authors.forename: Sonia M
authors.initials: SM
authors.lastname: Leach
authors.forename: Donald Y M
authors.initials: DY
authors.lastname: Leung
mesh_terms: D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism*; D020869:Gene Expression Profiling; D020868:Gene Silencing / Q000502:physiology; D006801:Humans; D007610:Kallikreins / Q000378:metabolism*; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D016329:Sp1 Transcription Factor / Q000037:antagonists & inhibitors* / Q000172:deficiency / Q000187:drug effects; D015854:Up-Regulation / Q000502:physiology*; D000094632:Thymic Stromal Lymphopoietin
chemical_list: D016207:Cytokines; D034741:RNA, Small Interfering; D016329:Sp1 Transcription Factor; D010447:Peptide Hydrolases; D007610:Kallikreins; D000094632:Thymic Stromal Lymphopoietin