Shi Xiaoyan, Wu Yongyan, Ai Zhiying, Liu Xin, Yang Liping, Du Juan, Shao Jingjing, Guo Zekun, Zhang Yong
College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China.
Cell Physiol Biochem. 2013;32(2):459-75. doi: 10.1159/000354451. Epub 2013 Aug 27.
BACKGROUND/AIMS: [corrected] Embryonic stem cells (ES cells) have the capacity to propagate indefinitely, maintain pluripotency, and differentiate into any cell type under defined conditions. As a result, they are considered to be the best model system for research into early embryonic development. AICA ribonucleotide (AICAR) is an activator of AMP-activated protein kinase (AMPK) that is thought to affect ES cell function, but its role in ES cell fate decision is unclear.
In this study, we performed microarray analysis to investigate AICAR downstream targets and further understand its effect on ES cells.
Our microarray data demonstrated that AICAR can significantly up-regulate pluripotency-associated genes and down-regulate differentiation-associated transcription factors. Although AICAR cannot maintain ES cell identity without LIF, it can antagonize the action of RA-induced differentiation. Using those differentially expressed genes identified, we performed gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis with the Database for Annotation, Visualization and Integrated Discovery (DAVID) online system. AICAR was not only shown to influence the AMPK pathway, but also act on other signaling pathways such as BMP, MAPK and TGF-β, to maintain the stemness of J1 ES cells. Furthermore, AICAR modulated ES cell epigenetic modification by altering the expression of epigenetic-associated proteins, including Dnmt3a, Dnmt3b, Smarca2, Mbd3, and Arid1a, or through regulating the transcription of long intervening non-coding RNA (lincRNA).
Taken together, our work suggests that AICAR is capable of maintaining ES cell self-renewal and pluripotency, which could be useful in future medical treatment.
背景/目的：胚胎干细胞（ES细胞）能够无限增殖、维持多能性，并在特定条件下分化为任何细胞类型。因此，它们被认为是研究早期胚胎发育的最佳模型系统。AICA核糖核苷酸（AICAR）是AMP激活的蛋白激酶（AMPK）的激活剂，被认为会影响ES细胞功能，但其在ES细胞命运决定中的作用尚不清楚。
在本研究中，我们进行了微阵列分析，以研究AICAR的下游靶点，并进一步了解其对ES细胞的影响。
我们的微阵列数据表明，AICAR可显著上调多能性相关基因，并下调分化相关转录因子。虽然没有白血病抑制因子（LIF）时AICAR不能维持ES细胞特性，但它可以拮抗视黄酸（RA）诱导的分化作用。利用鉴定出的那些差异表达基因，我们使用在线注释可视化整合发现数据库（DAVID）系统进行了基因本体论（GO）和京都基因与基因组百科全书（KEGG）通路分析。结果表明，AICAR不仅影响AMPK通路，还作用于其他信号通路，如骨形态发生蛋白（BMP）、丝裂原活化蛋白激酶（MAPK）和转化生长因子-β（TGF-β）通路，以维持J1 ES细胞的干性。此外，AICAR通过改变表观遗传相关蛋白（包括DNA甲基转移酶3a（Dnmt3a）、DNA甲基转移酶3b（Dnmt3b）、Smarca2、甲基化CpG结合结构域蛋白3（Mbd3）和AT丰富相互作用域1A（Arid1a））的表达，或通过调节长链居间非编码RNA（lincRNA）的转录，来调节ES细胞的表观遗传修饰。
综上所述，我们的研究表明AICAR能够维持ES细胞的自我更新和多能性，这可能对未来的医学治疗有用。
