Changes of glucocorticoid receptor expression and activity in rat alveolar macrophages induced by lipopolysaccharide
- VernacularTitle:脂多糖作用大鼠肺泡巨噬细胞糖皮质激素受体表达及活性变化
- Author:
Pin QIAN
;
Fang ZHANG
;
Guisheng QIAN
;
Weizhong CHEN
- Publication Type:Journal Article
- Keywords:
alveolar macrophage;
lipopolysaccharide;
glucocorticoid receptor;
dexamethasone;
glucocorticoid resistance
- From:Journal of Third Military Medical University
2003;0(22):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate changes of glucocorticoid receptor (GR) expression and activity in rat alveolar macrophages (AMs) induced by lipopolysaccharide (LPS) within 24 h. Methods Primary cultured AMs were divided randomly into LPS treatment group and LPS+Dex treatment group. The expressions of GR mRNA and GR protein in AMs at different time points were detected by RT-PCR and Western blot. Electrophoretic mobility shift assay (EMSA) was used to measure the GR activity in AMs. Results The expression level of GR mRNA decreased after LPS treatment, but returned to the normal level at 24 h after LPS treatment. The expression level of GR also decreased and reached the lowest level at 4 h after LPS treatment. GR activity also decreased, reached the lowest level at 1 h after LPS treatment, but was still lower than that in the normal control group at 24 h after treatment. Dexamethasone treatment had no obvious effect on GR activity during the late period of treatment. Conclusion LPS treatment (100 ng/ml) down-regulates the protein expression of GR, which maybe associated with the decreased expression of mRNA and accelerate degradation of GR protein. The activity of GR is inhibited sharply, resulting in glucocorticoid resistance.
