title: Retinoic acid down-regulates bone morphogenetic protein 7 expression in rat with cleft palate.
abstract: OBJECTIVE
  To evaluate the effects of retinoic acid (RA) on expression of bone morphogenetic protein 7 (BMP-7) in rat fetus with cleft palate, and the effects of RA on proliferation and apoptosis of osteoblasts.
  
  
  METHODS
  All-trans RA (ATRA) was used to induce congenital cleft palate in Wistar rat BMP-7 mRNA expression in maxillary bone tissue of fetal rats was measured by Northern blotting analysis. Flow cytometry and MTT assay were used to measure the apoptosis and proliferation of ATRA-treated MC-3T3-E1 cells. BMP-7 mRNA and protein expressions in ATRA-treated MC-3T3-E1 cells were detected by RT-PCR and Western blotting analysis.
  
  
  RESULTS
  ATRA could induce cleft palate of rat fetus. The incidence rate of cleft palate induced by 100 mg/kg AT-RA (45.5%) was significantly higher than 50 mg/kg ATRA (12.5%, P < 0.05). BMP-7 mRNA expression decreased in maxillary bone tissue of rat fetus with cleft palate. MC-3T3-E1 cells proliferation treated with 1 x 10(-6) mol/L ATRA decreased by 60%, the cell apoptosis increased by 2 times. BMP-7 mRNA and protein levels in MC-3T3-E1 cells treated with 1 x 10(-6) mol/L ATRA decreased by 60% and 80%, respectively, compared with ATRA-untreated cells (P < 0.05).
  
  
  CONCLUSIONS
  BMP-7 may play an important role in embryonic palate development RA may possess the ability to down-regulate cell proliferation through regulation of BMP-7 gene expression.
authors.affiliation: Department of Orthopedic Surgery, the First Affiliated Hospital, China Medical University, Shenyang 110001. g572@sina.com
authors.forename: Lei
authors.initials: L
authors.lastname: Guo
authors.forename: Yu-yan
authors.initials: YY
authors.lastname: Zhao
authors.forename: Shi-liang
authors.initials: SL
authors.lastname: Zhang
authors.forename: Kui
authors.initials: K
authors.lastname: Liu
authors.forename: Xiao-yu
authors.initials: XY
authors.lastname: Gao
mesh_terms: D016475:3T3 Cells; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001483:Base Sequence; D015152:Blotting, Northern; D055419:Bone Morphogenetic Protein 7 / Q000235:genetics*; D049109:Cell Proliferation / Q000187:drug effects; D002972:Cleft Palate / Q000235:genetics*; D017931:DNA Primers; D015536:Down-Regulation / Q000187:drug effects*; D005260:Female; D051379:Mice; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014212:Tretinoin / Q000494:pharmacology*
chemical_list: D055419:Bone Morphogenetic Protein 7; D017931:DNA Primers; D014212:Tretinoin