IkappaBbeta在炎症反应期间抑制和激活基因表达
Ping Rao1, Mathew S Hayden, Meixiao Long
1Department of Immunobiology and Department of Molecular Biophysics & Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
Nature
|August 27, 2010
概括
卡帕Bβ抑制剂 (IkappaBβ) 在炎症中起着双重作用. 虽然它的降解促进了亲炎性基因表达,但它的核形式延长了瘤亡因子-α (TNF-α) 的产生,提供了治疗点.
科学领域:
- 免疫学 免疫学 免疫学
- 分子生物学分子生物学
- 细胞信号传输 细胞信号传输
背景情况:
- 核因子-kappaB (NF-kappaB) 的激活驱动促炎性基因表达.
- 包括IkappaBbeta在内的kappaB (IkappaB) 蛋白的抑制剂,调节NF-kappaB的局部化.
- 在炎症反应中IkappaBbeta的精确体内功能仍然不完全理解.
研究的目的:
- 阐明在炎症反应过程中体内IkappaBbeta的特定生物作用.
- 研究IkappaBbeta影响NF-kappaB基因表达的机制,特别是TNF-alpha.
- 评估向IkappaBbeta在炎症性疾病中的治疗潜力.
主要方法:
- 产生和分析IkappaBbeta缺陷 (IkappaBbeta(-/-)) 的小鼠.
- 脂聚糖 (LPS) 刺激以诱导炎症反应.
- 对NF-kappaB激活,TNF-α mRNA表达和蛋白质水平进行定量分析.
- 染色体免疫沉 (ChIP) 测试用于检测基因促进体中的核NF-kappaB:IkappaBbeta复合体.
主要成果:
- 伊卡帕-贝塔降解释放NF-kappaB二次体,上调TNF-alpha等促炎基因.
- 矛盾的是,IkappaBbeta的缺失导致TNF-α表达显著减少,尽管NF-kappaB的激活正常.
- 核,低酸化IkappaBbeta与p65:c-Rel异构体形成复合体,结合TNF-alpha促进体并维持长时间的TNF-alpha表达.
- 伊卡帕Bbeta(-/-) 小鼠对LPS诱导的败血症冲击和原诱导的关节炎表现出耐药性.
结论:
- 伊卡帕贝塔表现出双重功能,既抑制又促进炎症反应.
- 核IkappaBbeta对于通过p65:c-Rel异构体持续产生TNF-alpha至关重要.
- 向IkappaBbeta为选择性抑制炎症条件下的慢性TNF-alpha产生提供了一个潜在的策略.
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