[7-Dehydrocholesterol reductase regulated the palatal development by the sonic hedgehog-bone morphogenetic protein 2...

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.

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.

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).

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.