摘要
目的:在模拟大鼠肺泡巨噬细胞炎症合并糖皮质激素治疗的条件下,阐明Bcl-2相关抗凋亡蛋白-1(BAG-1)的表达变化及其对糖皮质激素受体(GR)功能的调节作用。方法:Western blot检测脂多糖(LPS)和地塞米松(Dex)作用大鼠肺泡巨噬细胞BAG-1表达变化;免疫共沉淀法检测核蛋白中BAG-1与GR相互结合作用;相对荧光素酶法检测GR转录激活活性。结果:LPS和Dex作用后,细胞总蛋白中BAG-1 L表达增加,BAG-1 S表达无变化;核蛋白中只能检测到BAG-1 L,表达量在LPS作用24 h内逐渐增加;细胞核内BAG-1 L与GR在LPS和Dex作用后存在着相互结合,同时GR转录激活活性逐渐降低,其变化与核蛋白中BAG-1 L表达变化呈负相关。结论:LPS和Dex作用大鼠肺泡巨噬细胞BAG-1 L表达增加,与GR结合后共同转核,并抑制GR活性。该机制可能是感染条件下糖皮质激素抵抗的重要因素。
Objective： To investigate the expression changes of Bcl-2-associated athanogene 1 （BAG- 1 ） and its regulatory effect on the glucocorticoid receptor （GR） activity in rat alveolar macrophages in conditions of cell inflammation and glucocorticoid therapy. Methods ： The expression changes of BAG- 1 were detected by Western blot after lipopolysaccharide （LPS） and Dexamethasone （Dex） treatment of rat alveolar macrophages （AMs）, the interaction between BAG-1 and GR determined by immune copre cipitation experiment, and the transcriptional activation of GR measured by relative luciferase activity assay. Results：After LPS and Dex treatment, the expression of BAG-1 L in total protein increased but that of BAG-1S remained changed, BAG-1L rather than BAG-1S was detected in nuclear protein and its expression increased gradually within 24 hours, the interaction between BAG-1L and GR was observed in nucleoli, and the transcriptional activation of GR decreased, with a negative correlation between BAG-1L expression and GR activity. Conclusion：LPS and Dex acting on rat alveolar macrophages, the expression of BAG-1L increases, which, coupled with GR, translocates into nucleoli and inhibits GR activity. This might be the important mechanism that underlies glucocorticoid resistance in inflammation.
出处
《医学研究生学报》
CAS
2007年第11期1155-1158,1162,共5页
Journal of Medical Postgraduates
基金
中国博士后科学基金项目(批准号:20070411050)
江苏省博士后科研资助计划项目(批准号:0701023B)
