title: Dexamethasone Suppresses Oxysterol-Induced Differentiation of Monocytic Cells.
abstract: Oxysterol like 27-hydroxycholesterol (27OHChol) has been reported to induce differentiation of monocytic cells into a mature dendritic cell phenotype. We examined whether dexamethasone (Dx) affects 27OHChol-induced differentiation using THP-1 cells. Treatment of monocytic cells with Dx resulted in almost complete inhibition of transcription and surface expression of CD80, CD83, and CD88 induced by 27OHChol. Elevated surface levels of MHC class I and II molecules induced by 27OHChol were reduced to basal levels by treatment with Dx. A decreased endocytosis ability caused by 27OHChol was recovered by Dx. We also examined effects of Dx on expression of CD molecules involved in atherosclerosis. Increased levels of surface protein and transcription of CD105, CD137, and CD166 by treatment with 27OHChol were significantly inhibited by cotreatment with Dx. These results indicate that Dx inhibits 27OHChol-induced differentiation of monocytic cells into a mature dendritic cell phenotype and expression of CD molecules whose levels are associated with atherosclerosis. In addition, we examined phosphorylation of AKT induced by 27OHChol and effect of Dx, where cotreatment with Dx inhibited the phosphorylation of AKT. The current study reports that Dx regulates oxysterol-mediated dendritic cell differentiation of monocytic cells.
authors.affiliation: Department of Pharmacology, Pusan National University School of Medicine, Yangsan, Gyeongnam 50612, Republic of Korea.
authors.forename: Yonghae
authors.initials: Y
authors.lastname: Son
authors.affiliation: Department of Pharmacology, Pusan National University School of Medicine, Yangsan, Gyeongnam 50612, Republic of Korea.
authors.forename: Bo-Young
authors.initials: BY
authors.lastname: Kim
authors.affiliation: College of Veterinary Medicine and Bio-Safety Research Institute, Chonbuk National University, Iksan, Jeonbuk 54596, Republic of Korea.
authors.forename: Seong-Kug
authors.initials: SK
authors.lastname: Eo
authors.affiliation: Department of Microbiology & Immunology, Pusan National University School of Medicine, Yangsan, Gyeongnam 50612, Republic of Korea.
authors.forename: Young Chul
authors.initials: YC
authors.lastname: Park
authors.affiliation: Department of Pharmacology, Pusan National University School of Medicine, Yangsan, Gyeongnam 50612, Republic of Korea.
authors.forename: Koanhoi
authors.initials: K
authors.lastname: Kim
mesh_terms: D002454:Cell Differentiation; D003907:Dexamethasone / Q000494:pharmacology*; D006801:Humans; D009000:Monocytes / Q000378:metabolism; D000072376:Oxysterols / Q000009:adverse effects*
chemical_list: D000072376:Oxysterols; D003907:Dexamethasone