Dhcr7 Regulates Palatal Shelf Fusion through Regulation of Shh and Bmp2 Expression

Abstract

The aim of this study was to investigate the effect of the 7-dehydrocholesterol reductase (Dhcr7) gene and identify signaling pathways involved in regulation of embryonic palatogenesis. The expression ofDhcr7and its protein product were examined during murine normal embryonic palatogenesis via a reverse transcription polymerase chain reaction (RT-PCR) and Western blot (WB). RNA interference (RNAi) technology was used to inhibitDhcr7expression in a palatal shelf culturein vitro. The effects of Dhcr7 on palatogenesis and palatal fusion were examined by scanning electron microscopy (SEM). The expression changes of Dhcr7, Sonic Hedgehog (Shh), and bone morphogenetic protein-2 (Bmp2) were measured by RT-PCR and WB afterDhcr7gene silencing and the addition of exogenous cholesterol. The results showed that the palatal shelf failed to complete normal development and fusion whenDhcr7expression was inhibited. The inhibitory effect study of RNAi on the development of the palatal shelf supported that cholesterol supplementation did not alter the silencing of Dhcr7. Shh and Bmp2 expressions were reduced afterDhcr7gene silencing, and administration of exogenous cholesterol did not affect Dhcr7 expression; however Shh and Bmp2 expressions increased. We conclude thatDhcr7plays a role in growth of the palatal shelf and can regulate palatogenesis through alterations in the levels of Shh and Bmp2.