title: Retinoic acid downregulates microRNAs to induce abnormal development of spinal cord in spina bifida rat model.
abstract: OBJECTIVE
  MicroRNAs have been found in the developing central nervous system, but little is known about their functions in development, especially in the abnormal development of spinal cord in spina bifida. To this end, we have studied the mechanism of microRNAs involved in the morphogenesis of the spinal cord in all-trans-retinoic acid (RA)-treated spina bifida rat fetus.
  
  
  METHODS
  Timed-pregnant rats were gavage-fed RA, and embryos were obtained on 13.5, 15.5, 17.5, and 19.5 days. MicroRNAs' expression profile was analyzed by Northern blot. In situ apoptosis detection and microRNA in situ hybridization methods on sections of paraffin-embedded tissues were employed to explore the mechanism.
  
  
  CONCLUSIONS
  Administration of RA reduced the size of the spinal cord, probably as a consequence of increased cell death. There is a dramatic decrease in the expression of miR-9/9*, miR-124a and miR-125b, and Bcl2 and P53 as well in the sacral cord from E13.5 to E19.5 days post coitum. Our data showed that expression of these microRNAs was dysregulated in RA-treated spinal cord during embryonic development, suggesting that they may be involved in the development of the spinal cord.
authors.affiliation: Department of Genetics, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100005, China.
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Zhao
authors.forename: Da-Guang
authors.initials: DG
authors.lastname: Sun
authors.forename: Ju
authors.initials: J
authors.lastname: Wang
authors.forename: Shu-Rong
authors.initials: SR
authors.lastname: Liu
authors.forename: Chang-Yong
authors.initials: CY
authors.lastname: Zhang
authors.forename: Mei-Xiang
authors.initials: MX
authors.lastname: Zhu
authors.forename: Xu
authors.initials: X
authors.lastname: Ma
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000009:adverse effects*; D004195:Disease Models, Animal; D015536:Down-Regulation / Q000187:drug effects*; D004622:Embryo, Mammalian; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D008297:Male; D035683:MicroRNAs / Q000145:classification / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000002:abnormalities / Q000187:drug effects / Q000196:embryology; D016135:Spinal Dysraphism / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology; D014212:Tretinoin / Q000009:adverse effects*
chemical_list: D000970:Antineoplastic Agents; D035683:MicroRNAs; D014212:Tretinoin