Aim: To study the effects of dexamethasone (Dex) on expression of Th17 transcription factor retinoic acid-related orphan receptor gamma t(RORgammat)in asthma.
Methods: The BALB/c mice asthma model was induced by ovalbumin(OVA) with classic method.Thirty female mice were randomly divided into control group, asthmatic group and Dex treated group. The level of IL-17 in mice bronchoalveolar lavage fluid (BALF) and serum was measured by enzyme-linked immunosorbent assay(ELISA). Airway Responsiveness to acetylcholine chloride(Ach) was measured by a modified non-invasive method; The airway inflammation was evaluated by HE staining.The expression of RORgammat mRNA was measured by reverse transcription-polymerase chain reaction(RT-PCR).
Results: The level of RORgammat mRNA, IL-17 of asthmatic group were significantly higher than those of control group(P<0.01), which were significantly reduced by Dex compared with the asthmatic group(P<0.05).
Conclusion: Dex can inhibit the release of IL-17, whose mechanism may be the blockade of TH17 differentiation in asthmatic models by inhibit the RORgammat expression.