The Impact Of Progesterone On Airway Inflammation,Airway Remodeling,and The Mechanisms Of Steroid Resistance In Chronic Oxidative Stress Mice Models

OBJECTIVE:The aims of our research are to explore whether progesterone,or synergistically with glucocorticoids,attenuates the chronic airway inflammation and airway remodeling in a murine modeling of exposing to ozone（O₃）,and further to explore the potential effect of progesterone on glucocorticoid resistance.MATERIALS AND METHODS:70 C57/BL6 mice were divided randomly into 7groups as follows:air+phosphate buffer solution（PBS）,O₃+PBS,O₃+budesonide（BUD）,O₃+low progesterone,O₃+high progesterone,O₃+BUD+low progesterone and O₃+BUD+high progesterone.Respiratory function was detected using an animal ventilator.The mean linear intercept and the average bronchial wall thickness were measured by hematoxylin–eosin（HE）staining.The peribronchial collagen deposition was measured.The protein levels of interleukin（IL）-1β,IL-6,IL-8,IL-17A,tumor necrosis factor（TNF）-α,matrix metalloproteinase（MMP）8 and MMP9 in bronchoalveolar lavage fluid（BALF）were assessed via Enzyme linked immunosorbent assay（ELISA）.Western blot analysis was used to detect the levels of nuclear factor-κappa B（NF-κB）,IL-17A,glucocorticoids receptor（GR）,phospho-p38 mitogen activated protein kinase（MAPK）,and total p38 MAPK,hypoxia-inducible factor-1α（HIF-1α）,vascular endothelial growth factor（VEGF）,a-smooth muscle actin（α-SMA）,glycogen synthase kinase-3β（GSK-3β）.The expression of transforming growth factor（TGF）-β₁,MMP8,MMP9,VEGF and histone deacetylase 2（HDAC2）in lung tissue were determined by Immunohistochemical analyses.RESULTS:In O₃-exposed group,the levels of oxidative stress-related airway inflammatory cells infiltration density,mean linear intercept（Lm）,IL-1β,IL-6,IL-8,IL-17A,MMP8,MMP9,HIF-1α,VEGF,α-SMA,GSK-3β,activated NF-κB,and p38MAPK were greatly increased.FEV₂₅,GR,and HDAC2 were markedly decreased.Progesterone treatment dose-dependently led to a significant reduction of airway inflammatory cells infiltration density,mean linear intercept（Lm）,IL-1β,IL-6,IL-8,IL-17A,activated NF-κB and p38MAPK,and an increase of FEV₂₅ and GR.Progesterone combined with BUD resulted in dramatic changes,compared to monotherapy of BUD or progesterone.Progesterone attenuates the peribronchial collagen deposition,as well as the expression of MMP8,MMP9,HIF-1α,VEGF,α-SMA,and GSK-3βin BALF or lung tissues.Progesterone or BUD monotherapy has no effect on HDAC2 and GR production.Progesterone combines with BUD induce dramatically enhanced effects.CONCLUSION:Our findings demonstrate that chronic O₃ exposure has profound effects on airway inflammation and airway remodeling counteracted by progesterone.Progesterone acts synergistically with glucocorticoids in attenuating the airway inflammation and airway remodeling with dose-independent.Additionally,progesterone may,to some extent,improve the glucocorticoid resistance.