Centromere protein A dynamics in human pluripotent stem cell self-renewal, differentiation and DNA damage.
Centromere protein A dynamics in human pluripotent stem cell self-renewal, differentiation and DNA damage.
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DOI：
10.1093/hmg/ddq312
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发表时间：
2010-10-15
影响因子：
3.5
通讯作者：
Clark AT
中科院分区：
文献类型：
--
作者：
Ambartsumyan G;Gill RK;Perez SD;Conway D;Vincent J;Dalal Y;Clark AT
人类多能干细胞(HPSCs)在再生医学或作为了解人类胚胎发育的模型方面具有重要的前景。然而，hPSC增殖和自我更新所需的基本机制尚未完全揭示。所有真核生物的增殖都依赖于组蛋白H3变异着丝粒蛋白A(CENP-A)的高度调控表达。在目前的研究中，我们证明了hPSCs具有体细胞成纤维细胞中没有的CENP-A的独特信使核糖核酸(MRNA)储备。使用短发夹状RNA技术减少但不能去除CENP-A，我们发现CENP-A缺失的hPSCs仍然能够保持功能的着丝粒标记，而成纤维细胞则不能。然而，在诱导分化或DNA损伤时，CENP-A缺失的hPSCs停滞在G2/M期，并发生凋亡。HPSCDNA损伤后CENP-A的动态分析表明，照射60min后，在与γH_2AX和CENP-C相互排斥的多个小核灶中发现了CENP-A。此外，照射后6h，CENP-A缺失的hPSCs出现正常的凋亡反应；而在照射后24 h，CENP-A缺失的hPSCs的凋亡率明显高于对照组。综上所述，我们的结果表明，hPSCs通过灵活地减少在自我更新条件下维持功能着丝粒所需的CENP-A的量，并保持CENP-A mRNA的储备来重建分化或DNA损伤后的着丝粒，从而显示出维持基因组完整性的独特机制。
Human pluripotent stem cells (hPSCs) hold significant promise for use in regenerative medicine, or as a model to understand human embryo development. However, the basic mechanisms required for proliferation and self-renewal of hPSCs have not been fully uncovered. Proliferation in all eukaryotes is dependent upon highly regulated expression of the histone H3 variant Centromere protein A (CENP-A). In the current study, we demonstrate that hPSCs have a unique messenger ribonucleic acid (mRNA) reserve of CENP-A not found in somatic fibroblasts. Using short hairpin RNA technology to reduce but not ablate CENP-A, we show that CENP-A-depleted hPSCs are still capable of maintaining a functional centromeric mark, whereas fibroblasts are not. However, upon induction of differentiation or DNA damage, hPSCs with depleted CENP-A arrest in G2/M and undergo apoptosis. Analysis of CENP-A dynamics following DNA damage in hPSCs reveals that 60 min after irradiation, CENP-A is found in multiple small nuclear foci that are mutually exclusive to γH2AX as well as CENP-C. Furthermore, following irradiation, hPSCs with depleted CENP-A mount a normal apoptotic response at 6 h; however at 24 h, apoptosis is significantly increased in CENP-A-depleted hPSCs relative to control. Taken together, our results indicate that hPSCs exhibit a unique mechanism for maintaining genomic integrity by possessing the flexibility to reduce the amount of CENP-A required to maintain a functional centromere under self-renewing conditions, and maintaining a reserve of CENP-A mRNA to rebuild the centromere following differentiation or DNA damage.
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影响因子：
9.8
作者：
Dalal Y;Wang H;Lindsay S;Henikoff S
通讯作者：
Henikoff S
影响因子：
56.9
作者：
Humpherys, D;Eggan, K;Jaenisch, R
通讯作者：
Jaenisch, R
影响因子：
64.8
作者：
Gaspar-Maia A;Alajem A;Polesso F;Sridharan R;Mason MJ;Heidersbach A;Ramalho-Santos J;McManus MT;Plath K;Meshorer E;Ramalho-Santos M
通讯作者：
Ramalho-Santos M
DOI：
10.1073/pnas.0603227103
发表时间：
2006-09-19
影响因子：
11.1
作者：
Kocabas, Arif Murat;Crosby, Javier;Cibelli, Jose Bernardo
通讯作者：
Cibelli, Jose Bernardo
影响因子：
7.8
作者：
Jansen, Lars E. T.;Black, Ben E.;Foltz, Daniel R.;Cleveland, Don W.
通讯作者：
Cleveland, Don W.