中国神经再生研究(英文版) ›› 2017, Vol. 12 ›› Issue (3): 358-361.doi: 10.4103/1673-5374.202922

• 综述:脑损伤修复保护与再生 • 上一篇    下一篇

大脑中的端粒酶和mTOR:线粒体连接

  

  • 收稿日期:2017-03-07 出版日期:2017-03-15 发布日期:2017-03-15

Telomerase and mTOR in the brain: the mitochondria connection

Satomi Miwa, Gabriele Saretzki   

  1. Ageing Biology Centre and Institute for Cell and Molecular Biosciences, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK
  • Received:2017-03-07 Online:2017-03-15 Published:2017-03-15
  • Contact: Gabriele Saretzki, Ph.D.,gabriele.saretzki@newcastle.ac.uk.

摘要:

端粒酶复合物由端粒酶RNA和催化蛋白亚基TERT(端粒酶逆转录酶)以及各种相关蛋白组成。端粒酶的常规功能是抵抗端粒缩短,因此酶端粒酶活性是分裂细胞的主要特征。然而,TERT蛋白存在各种非端粒功能。这些非常规功能之一是TERT蛋白对细胞抗氧化应激的保护作用,其通过穿梭到细胞器中并定位于细胞器内而对线粒体产生影响。高等生物的TERT蛋白质具有线粒体定位序列作用,用于将TERT蛋白穿梭到细胞核外并进入线粒体中的最好已知刺激是氧化应激:急性或慢性,通过应用H2O2,高氧或辐照或固有外在性,例如衰老相关的细胞ROS水平增加。文中研究已经证明了线粒体定位的TERT可减少细胞氧化应激,并带来较低的核和线粒体DNA损伤水平和较少的凋亡。虽然本文已经提出了端粒酶复合物的各种功能,例如TERT与mtDNA的结合,通过与线粒体RNA复合来增加线粒体复合物I活性和TERT的逆转录酶活性,但是这些有益效果的确切机制尚不完全清楚。但已有研究表示这些不同线粒体功能的TERT和其线粒体内的保护功能之间没有直接的因果关系,并且对大多数这些功能进行了体外细胞系统研究。

ORCID:0000-0003-2100-8223(Gabriele Saretzki)

Abstract:

Telomerase is an enzyme that maintains telomeres in dividing cells using a template on its inherent RNA component. Additionally, the protein part TERT (Telomerase Reverse Transcriptase) has various non-canonical functions. For example, it can localize to mitochondria under increased stress and protect cells in vitro from oxidative stress, DNA damage and apoptosis. Recently it has been demonstrated that TERT protein persists in adult neurons in the brain and data emerge suggesting that it might have a protective function in these post-mitotic cells as well. We have recently published that TERT protein accumulated in mitochondria from brain tissue of mice that have undergone short-term dietary restriction (DR) and rapamycin treatment. This localization correlated to lower levels of oxidative stress in these brain mitochondria. Since rapamycin treatment decreases mTOR signaling which is also thought to play an important role for the beneficial effects of DR, we conclude that the mTOR pathway might be involved in the TERT localization and its effects in brain mitochondria in vivo. These data are in line with previous findings from our group about increased mitochondrial localization of TERT in Alzheimer’s disease (AD) brains and a protective function of TERT protein in neurons in vitro against pathological tau.

Key words: telomerase, brain, neuron, mitochondria, mTOR, ROS, dietary restriction, rapamycin