DOWN-REGULATION OF CYTOKINE SECRETION AND REPRESSION OF APOPTOSIS hDaxx IN MACROPHAGES  

作　　者：刘安元 万艳平 谭立志 吴移谋 余敏君 刘传爱 尹卫国 

机构地区：[1]Pathogenic Biology Institute, Nanhua University, Hengyang 421001

出　　处：《Chinese Journal of Cancer Research》2005年第1期44-48,共5页中国癌症研究（英文版）

基　　金：This work was supported by a grant from theEducation Committee of Hunan Province(No.02C391)

摘　　要：Objective: To investigate the regulation effects on LPS-mediated cytokine secretion and dexamethasone- induced apoptosis in macrophages by transient overexpression of hDaxx. Methods: An eukaryotic expression vector pEGFP/hDaxx, which could express a fusion protein GFP-Daxx, was transfected into macrophages. The expression and localization of GFP-hDaxx fusion protein was analyzed by fluorescent microscope and western blot. The effects of transient overexpression of GFP-hDaxx fusion protein on the lipopolysaccharide(LPS)-mediated secretion of TNF-α and IL-1β were determined by ELISA. Moreover, the dexamethasone-induced apoptosis was determined morphologically by Giemsa stain. Results: The results observed showed that GFP-hDaxx fusion protein overexpressed in macrophages and localized in nuclei but GFP in cytoplasm under fluorescent microscope. The overexpression of GFP-hDaxx fusion protein could be detected by Western blot with an antibody against C-terminal of hDaxx. In the group with overexpressed GFP-hDaxx fusion protein, the LPS-mediated cytokine secretion decreased remarkably at 1 h, 3 h, 6 h respectively after LPS stimulation, and the dexamethasone- induced apoptosis reduced notably at 6 h, 12 h and 24 h respectively after addition of dexamethasone. There were remarkable difference between pEGFP/hDaxx group and control group (P<0.01) at different time. Conclusion: Transient overexpression of hDaxx down-regulates LPS-mediated cytokine secretion in macrophages and inhibits dexamethasone-induced macrophages apoptosis.Objective: To investigate the regulation effects on LPS-mediated cytokine secretion and dexamethasone- induced apoptosis in macrophages by transient overexpression of hDaxx. Methods: An eukaryotic expression vector pEGFP/hDaxx, which could express a fusion protein GFP-Daxx, was transfected into macrophages. The expression and localization of GFP-hDaxx fusion protein was analyzed by fluorescent microscope and western blot. The effects of transient overexpression of GFP-hDaxx fusion protein on the lipopolysaccharide(LPS)-mediated secretion of TNF-α and IL-1β were determined by ELISA. Moreover, the dexamethasone-induced apoptosis was determined morphologically by Giemsa stain. Results: The results observed showed that GFP-hDaxx fusion protein overexpressed in macrophages and localized in nuclei but GFP in cytoplasm under fluorescent microscope. The overexpression of GFP-hDaxx fusion protein could be detected by Western blot with an antibody against C-terminal of hDaxx. In the group with overexpressed GFP-hDaxx fusion protein, the LPS-mediated cytokine secretion decreased remarkably at 1 h, 3 h, 6 h respectively after LPS stimulation, and the dexamethasone- induced apoptosis reduced notably at 6 h, 12 h and 24 h respectively after addition of dexamethasone. There were remarkable difference between pEGFP/hDaxx group and control group (P<0.01) at different time. Conclusion: Transient overexpression of hDaxx down-regulates LPS-mediated cytokine secretion in macrophages and inhibits dexamethasone-induced macrophages apoptosis.

关 键 词：HDAXX Cytokine secretion APOPTOSIS MACROPHAGES 

分 类 号：R96[医药卫生—药理学]