近期,，北京大學(xué)研究者揭示了miRNA在調(diào)節(jié)細(xì)胞周期中的起到的重要作用,，相關(guān)研究發(fā)表在The International Journal of Biochemistry & Cell Biology雜志上。
懷孕期間,，母體中葉酸的攝取不全會干擾胚胎的正常的發(fā)育及發(fā)育缺陷,。北京大學(xué)研究者證實了這種葉酸缺乏導(dǎo)致的哺乳動物胚胎發(fā)育缺陷是由miRNA特異性調(diào)控而導(dǎo)致,。研究者以小鼠胚胎干細(xì)胞(mESC)為研究模型，在葉酸缺乏培養(yǎng)基及完全培養(yǎng)基培養(yǎng)中分別進行細(xì)胞培養(yǎng),。結(jié)果表明,，葉酸缺乏培養(yǎng)基中的小鼠胚胎干細(xì)胞的凋亡率顯著升高，G1/G0期的細(xì)胞顯著積累,，且不能增殖,。隨后，經(jīng)表達(dá)譜分析的深入研究顯示,，葉酸缺乏的細(xì)胞中有12種miRNA表達(dá)量有顯著差異,。基因網(wǎng)絡(luò)構(gòu)建及GO信息學(xué)分析,，成功預(yù)測出miR-302a的靶基因Lats2可能是調(diào)節(jié)細(xì)胞增殖及周期性死亡的重要因子,。
為證實這一設(shè)想，研究者將miR-302a前體基因構(gòu)建至銳博生物特殊表達(dá)載體中(pmiR-RB-REPORT? vector),，經(jīng)轉(zhuǎn)錄加工形成成熟的miR-302a分子,，完全模擬內(nèi)源性分子的作用方式，證實miR-302a靶定Lats2 3’-UTR并抑制其基因的表達(dá),。通過轉(zhuǎn)染miR-302a mimcs(miR-Ribo? mimics)的進一步實驗表明,，miR-302a在轉(zhuǎn)錄水平影響Lats2的表達(dá)，影響胚胎形成過程中小鼠胚胎干細(xì)胞增殖及差異化發(fā)育,。這一系列研究,，揭示了改變胚胎干細(xì)胞特定的miRNA的表達(dá)將調(diào)節(jié)哺乳動物的生長，可能是響應(yīng)營養(yǎng)脅迫早期的調(diào)控器,。
這一研究通過構(gòu)建miRNA及miRNA mimics轉(zhuǎn)染,，成功的驗證了miRNA在細(xì)胞發(fā)育過程中的重要作用。銳博生物經(jīng)驗豐富的研發(fā)團隊提供的miRNA mimic,、miRNA inhibitor,、miRNA agomir、miRNA antagomir,、miRNA 表達(dá)譜芯片,、miRNA 新一代高通量測序等簡單高效的miRNA研究工具，為研究者解開miRNA參與的生命之謎提供有力的支持,。（生物谷Bioon.com)
DOI:10.1016/j.biocel.2012.07.014,
PMC:
PMID:
Mechanism of folate deficiency-induced apoptosis in mouse embryonic stem cells: Cell cycle arrest/apoptosis in G1/G0 mediated by microRNA-302a and tumor suppressor gene Lats2
Yan Lianga, b, , Yuanyuan Lib, , Zhengli Lib, , Zhuo Liub, , Zhiping Zhangc, , Shaoyan Changd, , Jianxin Wua, b, , ,
Deficiencies in maternal diet, such as inadequate intake of folate, can inhibit normal development and lead to developmental defects. MicroRNAs (miRNAs) may play a role in mediating the effects of folate deficiency in the growing mammalian embryo, although conclusive evidences to support that possibility are not yet available. The goal of the present study was to investigate whether and how folate deprivation alters the properties of mouse embryonic stem cells (mESCs) in culture. For this purpose, mESCs were cultured in folate-deficient or complete culture medium. The results show that folate-deficient mESCs have a significantly higher rate of apoptosis, accumulate in G0/G1 and fail to proliferate. Expression profiling revealed several miRs and many mRNAs are differently expressed in folate-deficient cells. RT-PCR data confirmed differential expressions of 12 miRNAs in folate-deficient cells. Furthermore, bioinformatics analyses and in vitro studies suggested that miR-302a plays a critical role in mediating the effects of folate on cell proliferation and cell cycle-specific apoptosis by targeting Lats2 gene. Together, these results suggest that the effects of folate deficiency on mammalian development may be mediated by miRNAs that regulate proliferation and/or cell cycle progression in ESCs.
