Msx1在小鼠腭板发育中的作用及机制研究

Functional Analysis and Molecular Mechanism of Msx1 in Mouse Palate Development

哺乳动物腭板发育受到多个信号通路以及转录因子的精密调控,参与该过程的基因突变常常会导致腭裂.Msx1是腭板发育调控的关键基因,其突变与腭裂密切相关.本研究利用条件性Msx1过表达小鼠,采用HE染色分析Msx1过表达小鼠腭板的表型,采用免疫组化研究Msx1过表达小鼠腭板的细胞增殖和腭板骨分化情况,利用RNA-seq测序分析Msx1过表达小鼠腭板基因表达变化.结果表明:小鼠间充质过表达Msx1会导致腭裂,腭板细胞中增殖特异性标志物PHH3表达明显下调,成骨细胞分化的调节因子SP7表达显著下调,成骨细胞分化调节因子RUNX2水平无显著变化.过表达Msx1导致颅面部器官发育的重要调节因子FOX、ALX、BMP、WNT、TBX等家族分子的基因表达发生显著变化.Msx1在腭板发育的细胞增殖、细胞分化等方面起关键调控作用,并对多种颅面器官发育的重要基因表达起调控作用.

The development of mammalian palatal shelves is regulated by multiple signaling pathways and transcription factors.Mutations of the genes that involved in this process often lead to cleft palate.The transcription factor Msx1 is a key gene in the regulation of palatal organogenesis,and mutations of Msx1 are closely related to cleft palate.In this study,a conditional Msx1 was used to overexpress mouse allele.Furthermore,we analyzed the palatal phenotype by HE staining,investigated the cell proliferation and differentiation by immunohistochemistry,and evaluated the gene expression changes by RNA-seq.Results showed that overexpression of Msx1 in mouse mesenchymal cells could result in cleft palate,decrease expression of the proliferation-specific marker PHH3,and significantly reduce expression of SP7.By contrast,the level of RUNX2 expression had no significantly changes.RNA-seq analysis revealed that overexpression of Msx1 leaded to significant changes in the gene expression of family molecules such as FOX,ALX,BMP,WNT,and TBX,which are important regulators of craniofacial organ development.In summary,Msx1 plays an important role in the cell proliferation and differentiation of palatal plate development,as well as in regulating the expression of multiple key genes of craniofacial organ development.