title: Dexamethasone affects mouse olfactory mucosa gene expression and attenuates genes related to neurite outgrowth.
abstract: BACKGROUND
  Olfaction is one of the important senses for humans. Systemic glucocorticoids are the most commonly used medications for olfactory loss because of their strong anti-inflammatory effects. However, their effect on olfactory function is still controversial and the precise mechanism is not clear. To gain a global view of the effect of systematic glucocorticoid treatment on gene expression in the olfactory mucosa (OM), we profiled these changes in a murine model of olfaction in order to identify underlying molecular mechanisms.
  
  
  METHODS
  C57BL/6 mice were injected daily for 2 weeks (WK2) with dexamethasone (DEX, intraperitoneally, 1 mg/kg body weight) vs 1 day of DEX (D1) vs controls, which received saline (Ctrl) (n = 9/group). Total RNA from the OM was used to analyze global gene expression. Genes showing changes in expression were compared using the Database for Annotation, Visualization and Integrated Discovery (DAVID, v6.7) and the General Olfactory Sensitivity Database (GOSdb; http://genome.weizmann.ac.il/GOSdb).
  
  
  RESULTS
  Between the WK2 and Ctrl groups, 3351 genes were differentially expressed, of which 236 genes were related to olfactory function. Genes involved in axon guidance, cell projection, and inflammation were enriched and overlapped significantly with those in the GOSdb.
  
  
  CONCLUSIONS
  Systemic glucocorticoids exert effects on transcription of a notable number of genes in the OM and appear to orchestrate changes related to axon guidance, cell projection, and inflammation. Further examination may allow targeted therapies that lack the side effects of this category of medication.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Tian
authors.affiliation: Section of Otolaryngology-Head and Neck Surgery, Department of Surgery, The University of Chicago, Chicago, IL.
authors.forename: Jayant M
authors.initials: JM
authors.lastname: Pinto
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xin
authors.affiliation: Peking University Hepatology Institute, Peking University People's Hospital, Beijing, China.
authors.forename: Henghui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
authors.forename: Zhifu
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
authors.forename: Yongxiang
authors.initials: Y
authors.lastname: Wei
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D003907:Dexamethasone / Q000008:administration & dosage*; D015870:Gene Expression / Q000187:drug effects; D020869:Gene Expression Profiling; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D023421:Models, Animal; D009414:Nerve Growth Factors / Q000235:genetics*; D009831:Olfactory Mucosa / Q000187:drug effects* / Q000502:physiology; D012903:Smell / Q000187:drug effects* / Q000235:genetics
chemical_list: D000893:Anti-Inflammatory Agents; D009414:Nerve Growth Factors; D003907:Dexamethasone
keywords: corticosteroid use; epithelial cell; microarray; olfaction; olfactory disorders