Wang Lin-Lin, Zhang Zhaofeng, Li Qiong, Yang Ruiyue, Pei Xinrong, Xu Yajun, Wang Junbo, Zhou Shu-Feng, Li Yong
Department of Nutrition and Food Hygiene, School of Public Health, Peking University, Beijing 100191, PR China.
Hum Reprod. 2009 Mar;24(3):562-79. doi: 10.1093/humrep/den439. Epub 2008 Dec 17.
microRNAs (miRNAs) play an important role in development and are associated with birth defects. Data are scant on the role of miRNAs in birth defects arising from exposure to environmental factors such as alcohol.
In this study, we determined the expression levels of 509 mature miRNAs in fetal mouse brains with or without prenatal ethanol exposure using a miRNA microarray technique, verified by northern blot and PCR. Mouse embryos in culture were used to examine the effect of ethanol treatment on expression of the putative target genes of miR-10a (Hoxa1 and other Hox members) at mRNA and protein level. Open field and Morris water maze tests were also performed at post-natal day 35.
Ethanol treatment induced major fetal teratogenesis in mice and caused mental retardation in their offspring, namely lower locomotor activity (P < 0.01) and impaired task acquisition. Of the screened miRNAs, miR-10a, miR-10b, miR-9, miR-145, miR-30a-3p and miR-152 were up-regulated (fold change >1.5) in fetal brains with prenatal ethanol exposure, whereas miR-200a, miR-496, miR-296, miR-30e-5p, miR-362, miR-339, miR-29c and miR-154 were down-regulated (fold change <0.67). Both miR-10a and miR-10b were significantly up-regulated (P < 0.01) in brain after prenatal ethanol exposure. Ethanol treatment also caused major obstruction in the development of cultured embryos, with down-regulated Hoxa1. Co-incubation with folic acid blocked ethanol-induced teratogenesis, with up-regulated Hoxa1 and down-regulated miR-10a (P < 0.01).
The study provided new insights into the role of miRNAs and their target genes in the pathogenesis of fetal alcohol syndrome.
微小RNA（miRNA）在发育过程中发挥重要作用，且与出生缺陷相关。关于miRNA在因暴露于酒精等环境因素而导致的出生缺陷中所起作用的数据很少。
在本研究中，我们使用miRNA微阵列技术测定了产前暴露于乙醇或未暴露于乙醇的胎鼠大脑中509种成熟miRNA的表达水平，并通过Northern印迹和PCR进行验证。使用培养的小鼠胚胎在mRNA和蛋白质水平上检测乙醇处理对miR-10a（Hoxa1和其他Hox成员）假定靶基因表达的影响。在出生后第35天还进行了旷场试验和莫里斯水迷宫试验。
乙醇处理诱导小鼠出现严重的胎儿畸形，并导致其后代智力发育迟缓，即运动活性降低（P < 0.01）和任务获取受损。在筛选出的miRNA中，产前暴露于乙醇的胎鼠大脑中miR-10a、miR-10b、miR-9、miR-145、miR-30a-3p和miR-152上调（倍数变化>1.5），而miR-200a、miR-496、miR-296、miR-30e-5p、miR-362、miR-339、miR-29c和miR-154下调（倍数变化<0.67）。产前暴露于乙醇后，大脑中的miR-10a和miR-10b均显著上调（P < 0.01）。乙醇处理还导致培养胚胎发育出现严重障碍，Hoxa1表达下调。与叶酸共同孵育可阻断乙醇诱导的致畸作用，使Hoxa1上调且miR-10a下调（P < 0.01）。
该研究为miRNA及其靶基因在胎儿酒精综合征发病机制中的作用提供了新的见解。
