title: [7-Dehydrocholesterol reductase regulated the palatal development by the sonic hedgehog-bone morphogenetic protein 2 signal pathway].
abstract: OBJECTIVE
  To investigate the effect of 7- dehydrocholesterol reductas (Dhcr-7) gene silencing on the palatal development by sonic hedgehog (Shh)-bone morphogenetic protein2(BMP-2) signal pathway in vitro.
  
  
  METHODS
  A total of 60 pairs of palatal shelves fromgestation day (GD) 13.5 mouse embryos were divided into three groups (A, B, C) of 20 randomly. In group A (control), palatal shelves were cultured with medium containing no cholesterol.In group B (Dhcr-7-siRNA), palatal shelves were cultured without cholesterol medium but containing Dhcr-7 siRNA adenovirus. After 48h, the culture medium of groups A and B were changed with medium without cholesterol. In group C (cholesterol), palatal shelves were cultured without cholesterol medium but containing Dhcr-7 siRNA adenovirus. After 48h, the culture medium of group C was changed with medium containing 600 mg/L cholesterol. After 72h again, tissues dyeing and scanning electron microscope (SEM) technique were used to observe morphological changes of palates. Both RT-PCR and Western blottingtechniques were used to measure mRNA and protein expressions for Dhcr-7, Shh, and BMP-2, respectively.
  
  
  RESULTS
  The tissues dyeing and SEM showedthat the palates fusedin groups A and Candthe palates did not fuse in group B eventually. The expression of both mRNA and proteins for Shh and BMP-2 in group B wasdecreased with the Dhcr-7 reduction. In group B, the mRNA and protein expression of Shh was separately 0.063±0.018 and 0.092±0.065;the mRNA and protein expression quantity of BMP- 2 was separately 0.054±0.018 and 0.049±0.021. In group A, the mRNA and protein expression of Shh was separately 0.667±0.093 and 0.639±0.078;the mRNA and protein expression of BMP-2 was separately 0.591 ± 0.043 and 0.569 ± 0.081. The difference of Shh and BMP- 2 mRNA and protein expression between A and B group were statistically significant separately (P < 0.05). The expression of both mRNA and protein for Dhcr-7 (0.074±0.034 and 0.075±0.028) did not changebasicallyin group C, compared with the Dhcr- 7expression of mRNA and protein (0.083±0.045; 0.067±0.065) in group B, the difference wasnot statistically significant(P > 0.05). In group C, the mRNA and protein expressionof Shh (0.649±0.085 and 0.608±0.092) and BMP-2 (0.578±0.062 and 0.548±0.065) were significantly increased. The difference of Shh and BMP-2 mRNA and protein expression between B and C group were statistically significant separately (P < 0.05).
  
  
  CONCLUSIONS
  Dhcr-7 could influence the expression of Shh and BMP-2. Dhcr-7 reductase regulated the palatal development by the Shh-BMP-2 signal pathway.
authors.affiliation: Department of Paediatric Dentistry, The Affiliated Hospital of Qingdao University, Qingdao Shandong 266003, China.
authors.forename: Daizun
authors.initials: D
authors.lastname: Zhang
authors.forename: Yaoxiang
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Email: wenlinxiao@sina.com.
authors.forename: Wenlin
authors.initials: W
authors.lastname: Xiao
authors.forename: Cuizhu
authors.initials: C
authors.lastname: Zhuang
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000235:genetics / Q000378:metabolism*; D002784:Cholesterol; D017077:Culture Media, Conditioned / Q000737:chemistry / Q000494:pharmacology; D053823:Hedgehog Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000378:metabolism*; D010159:Palate / Q000254:growth & development* / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D011897:Random Allocation; D015398:Signal Transduction
chemical_list: D055396:Bone Morphogenetic Protein 2; D017077:Culture Media, Conditioned; D053823:Hedgehog Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C509239:SHH protein, human; D002784:Cholesterol; D044925:Oxidoreductases Acting on CH-CH Group Donors; C019995:7-dehydrocholesterol reductase