Abstract

Core binding factor {beta} (Cbfb) is a cofactor of Runx transcription factors. Among Runx transcription factors, Runx1 is a prerequisite for anterior-specific palatal fusion. However, whether Cbfb serves as a modulator or obligatory factor in Runx signaling that regulates palatogenesis is unclear. We herein report that Cbfb is essential and indispensable in anterior palatogenesis. Palatal fusion in Cbfb mutants is disturbed due to failed disintegration of the fusing epithelium specifically at the anterior portion, as is observed in Runx1 mutants. In this mutants, the Tgfb3 expression is disturbed at the corresponding area of the failed palatal fusion, where phosphorylation of Stat3 is also disturbed. TGFB3 protein rescues the palatal fusion in vitro. Strikingly, the anterior cleft palate in Cbfb mutants is further rescued by pharmaceutical application of folic acid that activates suppressed Stat3 phosphorylation and Tgfb3 expression in vitro. With these findings, we provide the first evidence that Cbfb is a prerequisite for anterior palatogenesis as an obligatory cofactor in the Runx1/Cbfb-Stat3-Tgfb3 signaling axis. Furthermore, the rescue of the mutant cleft palate using folic acid may elucidate potential therapeutic targets by Stat3 modification for the prevention and pharmaceutical intervention of cleft palate.\n\nSummary StatementEpithelial deletion of Cbfb results in an anterior cleft palate with impaired fusion of the palatal process and folic acid application rescues the mutant phenotype with Stat3 activation in vitro.