title: The possible separation of 12-O-tetradecanoylphorbol-13-acetate-induced skin inflammation and hyperplasia by compound A.
abstract: Activated glucocorticoid receptor (GR) acts via two different mechanisms: transcriptional regulation that requires DNA-binding, and protein-protein interaction between GR and other transcription factors, such as nuclear factor kappa B (NF-κB) or activator protein 1 (AP-1). It has been postulated that many important effects of glucocorticoids, including their anti-inflammatory properties, depend on GR's transrepressive effects on NF-κB and AP-1. In the present study, we have employed a TPA-induced model of skin inflammation and epidermal hyperplasia to determine whether partial activation of the glucocorticoid receptor by compound A (CpdA) is sufficient to reverse the effect of TPA treatment. CpdA is a nonsteroidal GR modulator with high binding affinity, is capable of partial activation of GR. Topical application of TPA twice per week for 2 wk results in inflammation and epidermal hyperplasia. TPA treatment also elevates levels of c-jun (AP-1 component), cyclooxygenase-2 (COX-2), p50 (NF-κB component), interleukin-6 (IL-6), and tumor necrosis factor (TNF) in the skin. Fluocinolone acetonide (FA) (a full GR agonist) was able to completely reverse the above effects of TPA. When applied alone, CpdA increased the epidermal thickness and keratinocyte proliferation as well as levels of c-jun, COX-2, IL-6, and IFN-γ. However, CpdA treatment resulted in a decrease in the number of p50 positive cells induced by TPA, suggesting its role in inhibition of NF-κB. The level of metallothionein-1 mRNA, regulated by GR was also significantly decreased in skin samples treated with CpdA. Our results suggest that CpdA is able to inhibit GR transactivation and activate only some transrepression properties of GR.
authors.affiliation: Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
authors.forename: Piotr
authors.initials: P
authors.lastname: Kowalczyk
authors.forename: Magdalena C
authors.initials: MC
authors.lastname: Kowalczyk
authors.forename: Jacob J
authors.initials: JJ
authors.lastname: Junco
authors.forename: Olga
authors.initials: O
authors.lastname: Tolstykh
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kinjo
authors.forename: Ha
authors.initials: H
authors.lastname: Truong
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Walaszek
authors.forename: Margaret
authors.initials: M
authors.lastname: Hanausek
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Slaga
mesh_terms: D000085:Acetates / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D051546:Cyclooxygenase 2 / Q000032:analysis / Q000235:genetics; D016207:Cytokines / Q000032:analysis / Q000276:immunology; D003875:Drug Eruptions / Q000188:drug therapy* / Q000235:genetics / Q000276:immunology / Q000473:pathology*; D004817:Epidermis / Q000187:drug effects / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D005260:Female; D006965:Hyperplasia / Q000139:chemically induced / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D051379:Mice; D018632:Mice, Inbred SENCAR; D016328:NF-kappa B / Q000032:analysis / Q000235:genetics; D016755:Proto-Oncogene Proteins c-jun / Q000032:analysis / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D011965:Receptors, Glucocorticoid / Q000819:agonists / Q000235:genetics / Q000276:immunology*; D012867:Skin / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D013755:Tetradecanoylphorbol Acetate; D015533:Transcriptional Activation / Q000187:drug effects; D014439:Tyramine / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: C104564:2-(4-acetoxyphenyl)-2-chloro-N-methylethylamine; D000085:Acetates; D016207:Cytokines; D016328:NF-kappa B; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D011965:Receptors, Glucocorticoid; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2; D013755:Tetradecanoylphorbol Acetate; D014439:Tyramine