43 KB1142 KB41 KB199220252003Blumenberg, Miroslav Lj.Kaneko, TakehikoLong, Wendy SRao, Larmi S.številka:1letnik:12str. 3-14ISSN:1318-4458COBISSID:16233689URN:URN:NBN:SI:doc-X7YGLYKVenSlovene Welding SocietyActa dermatovenerologica Alpina, Pannonica et AdriaticabiokemijaBlot, WesternBlotting, WesterndermatologijaDrug EffectsElectrophoresis, Polyacrylamide GelElektroforeza, poliakrilamid gelGrowth SubstancesKeratinocitiKeratinocytesneoplasmNF-kapa BNf-Kappa BProto-Oncogene Proteins C-FosProto-Oncogene Proteins C-JunProto-onkogene beljakovine c-fosProto-onkogene beljakovine c-junRastne snoviTranscription Factor Ap-1Transcription Factor, Sp1Transcription FactorsTranskripcija, faktorjiTranskripcijski faktor AP-1Transkripcijski faktor Sp1tumorTumor Necrosis FactorTumor nekrotizirajoči faktorRegulation of transcription factor activity by extracellular signals in epidermal keratinocytes|Environmental signals, such as growth factors and cytokines, modulate the activity of nuclear transcription factors, thus regulating gene expression. This regulation is of particular importance in skin where a large variety of signals, especially in activated keratinocytes associated with disease states or wound healing, stimulate new gene expression in keratinocytes. In this study, we used electrophoretic mobilityshift assays (EMSA) to define the changes in DNA binding activity of transcription factors in such activated keratinocytes. Normal human epidermal keratinocytes were grown in a serum-freemedium and treated with 10% fetal calf serum, EGF, TNFa or Oncostatin M (OsM) for different periods of time. Wholecell extracts, without purification of the nuclei, were prepared and combined with a series of 32-P-labeled synthetic oligonucleotide probes containing consensus binding sequences for the transcription factors AP1, NF`, C/EBPbeta, and Sp1. Serum activates all four transcription factors in keratinocytes; TNFa activates APi,NF` and C/EBPbeta, but not Spi, whereas EGF activates AP1 and NF`, but notC/EBP/` or Sp1. On the other hand, OsM specifically activates Sp1. The activation of transcription factors is transient, usually reaching a peak 20 to 60 minutes after stimulation and returning to the basal level after two hours. We conclude that different signaling pathways are activated in responseto various extracellular signals. This orchestrates the activity of transcription factors on the promoters of regulated genes in epidermis thus determining the levels of gene expressionTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaZdruženje slovenskih dermatovenerologov