Mouse Models of Orofacial Clefts: SHH and TGF-β Pathways.

Birth defects have always been one of the most important diseases in medical research as they affect the quality of the birth population. Orofacial clefts (OFCs) are common birth defects that place a huge burden on families and society. Early screening and prevention of OFCs can promote better natal and prenatal care and help to solve the problem of birth defects. OFCs are the result of genetic and environmental interactions; many genes are involved, but the current research has not clarified the specific pathogenesis. The mouse animal model is commonly used for research into OFCs; common methods of constructing OFC mouse models include transgenic, chemical induction, gene knockout, gene knock-in and conditional gene knockout models. Several main signal pathways are involved in the pathogenesis of OFCs, including the Sonic hedgehog (SHH) and transforming growth factor (TGF)-β pathways. The genes and proteins in each molecular pathway form a complex network to jointly regulate the formation and development of the lip and palate. When one or more genes, proteins or interactions is abnormal, OFCs will form. This paper summarises the mouse models of OFCs formed by different modelling methods, as well as the key pathogenic genes from the SHH and TGF-β pathways, to help to clarify the pathogenesis of OFCs and develop targets for early screening and prevention.