Ethanol exposure induces differential microRNA and target gene expression and teratogenic effects which can be suppressed by folic acid supplementation.
BACKGROUND
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.


METHODS
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.


RESULTS
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).


CONCLUSIONS
The study provided new insights into the role of miRNAs and their target genes in the pathogenesis of fetal alcohol syndrome.
Wang
Lin-Lin
LL
Department of Nutrition and Food Hygiene, School of Public Health, Peking University, Beijing 100191, PR China.
Zhang
Zhaofeng
Z
Li
Qiong
Q
Yang
Ruiyue
R
Pei
Xinrong
X
Xu
Yajun
Y
Wang
Junbo
J
Zhou
Shu-Feng
SF
Li
Yong
Y
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D019587:Dietary Supplements; D000431:Ethanol / Q000378:metabolism / Q000494:pharmacology*; D005260:Female; D005492:Folic Acid / Q000627:therapeutic use*; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000378:metabolism; D007150:Immunohistochemistry / Q000379:methods; D018782:Maze Learning; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs; D012333:RNA, Messenger / Q000378:metabolism; D013723:Teratogens
D018398:Homeodomain Proteins; D035683:MicroRNAs; D012333:RNA, Messenger; D013723:Teratogens; D000431:Ethanol; D005492:Folic Acid