[Mechanism of GLI3 gene transcription regulation in idiopathic congenital talipes equinovarus].

ABSTRACT

OBJECTIVE: To investigate the mechanism of transcription regulation of GLI3 gene in idiopathic congenital talipes equinovarus. METHODS: pGL3-Gli3 luciferase report vectors were constructed, and the activity of Gli3 promoter was explored. A P-Match software was used to analyze the sequence upstream of the transcription start site of rat Gli3 gene, which was subsequently verified with chromatin immunoprecipitation assay (CHIP) and electrophoretic mobility shift assay (EMSA). Expression of the Gli3 gene was analyzed in L6 cells transfected with Hoxd13 small interference RNA(siRNA) and Hoxd13 expression vectors. RESULTS: The 5' region of rat Gli3 gene contains two potential binding sites for the Hoxd13 protein. CHIP and EMSA assays both confirmed that Hoxd13 can directly bind with site 2. As shown in L6 cells, expression of Gli3 may be enhanced with silencing of Hoxd13, whilst exogenous expression of Hoxd13 can down-regulate transcription of Gli3. CONCLUSION: Hoxd13 can directly regulate the expression of Gli3 gene through a Hoxd13 binding site in the limb of rat embryo.