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在小鼠的急性junctophilin敲击后,破坏了结节膜综合体和过度活跃的诺丁受体
Ralph J van Oort1, Alejandro Garbino, Wei Wang
1Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX 77030, USA.
Circulation
|February 23, 2011
概括
非林-2 (JPH2) 对于心脏功能至关重要,调节释放和肌肉收缩. 降低JPH2水平会损害心脏收缩性,导致心力衰竭和死亡率增加.
科学领域:
- 心血管生物学 心血管生物学
- 分子心脏病学分子心脏病学
- 肌肉生理学 肌肉生理学
背景情况:
- 条纹肌肉中的刺激-收缩合依赖于电压激活的Ca2+通道和sarcoplasmic网膜 Ca2+释放通道之间的通信.
- 之前的研究表明,在生殖系的junctophilin-2 (JPH2) 淘汰小鼠中,胚胎死亡率很高,但其在心脏结膜复合体形成和Ca2+诱导的Ca2+释放中的具体作用尚不清楚.
- 在患有多变性心肌病的患者中,已经确定了JPH2中的功能丧失突变.
研究的目的:
- 阐明Junctophilin-2 (JPH2) 在心脏功能中的重要作用.
- 研究降低JPH2水平对兴奋 - 收缩合和心脏收缩性的影响.
主要方法:
- 开发了一种新的心脏特异性RNA干扰方法,以有条件地降低junctophilin-2 (JPH2) 蛋白质水平.
- 利用短毛RNA (shRNA) 介导的淘汰来准心脏肌细胞中的JPH2表达.
主要成果:
- 心脏特异性的JPH2敲击导致心脏收缩能力受损,心力衰竭和死亡率增加.
- JPH2 缺陷导致激发-收缩合增益的损失.
- 观察到连接膜复合体的减少和等离子体lemma-sarcoplasmic网膜距离的变异性增加.
结论:
- 失去JPH2显著影响心脏肌细胞中的Ca2+释放通道不活化,这表明它具有新的调节作用.
- 俊菲林-2在心脏内细胞内Ca2+释放中起着至关重要的作用.
- 条件淘汰JPH2突出了它在维持心脏收缩性和预防心力衰竭方面的重要功能.
相关概念视频
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01:29Relaxation of Skeletal Muscles
The period of muscle contraction primarily influences the duration of stimulation at the neuromuscular junction (NMJ), the presence of free calcium ions in the sarcoplasm, and the availability of energy or ATP to support contractions.
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open.
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open.