宿主体转录因子Irx5建立了小鼠心室心室再极化梯度
Danny L Costantini1, Eric P Arruda, Pooja Agarwal
1Program in Cardiovascular Research, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada.
Cell
|October 22, 2005
概括
宿主体转录因子Irx5通过抑制Kv4.2通道表达来建立心脏再极化梯度. 这种梯度对于协调心脏再极化和预防致命心律失常至关重要.
科学领域:
- 心血管生理学心血管生理学
- 分子心脏病学分子心脏病学
- 心脏电生理学 心脏电生理学
背景情况:
- 节奏性心脏收缩依赖于有组织的电波前线传播.
- 在由电流驱动的心脏再极化中,空间异质性至关重要.
- 反极化梯度的破坏与心脏病和心律失常有关.
研究的目的:
- 阐明建立心脏再极化梯度的机制.
- 研究同居域转录因子Irx5在再极化中的作用.
- 了解再极化梯度干扰如何导致心律失常.
主要方法:
- 使用了缺乏Irx5基因的小鼠模型.
- 在心肌组织中评估Kv4.2通道表达.
- 测量了短暂的外向电流,I{\displaystyle I}到f{\displaystyle f} .
- 研究了Irx5,Kv4.2和转录抑制剂mbop之间的相互作用.
主要成果:
- 缺少Irx5可以消除心脏再极化梯度.
- 缺少Irx5导致内心肌中的Kv4.2表达增加.
- 这导致I{\to,f}升高,并增加了对心律失常的敏感性.
- Irx5 形成了一个与 Kv4.2 相反的梯度,并通过 mBop.抑制其表达.
结论:
- 一个Irx5抑制剂梯度负面调节心脏通道基因表达.
- 这就建立了对协调复极化至关重要的反向I{\displaystyle I}到f{\displaystyle I}梯度.
- 适当的心脏再极化梯度可以预防心律失常并维持心律.
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