Dexamethasone Induces Apoptosis of Embryonic Palatal Mesenchymal Cells Through the GATA-6/Bone Morphogenetic Protein-2/p38 MAPK Pathway.

Exposure to dexamethasone (DEX) causes cleft palate at high rates. Our previous studies proved that GATA binding protein 6 (GATA-6)/bone morphogenetic protein-2 (BMP-2) mediated apoptosis is related to DEX-induced cleft palate, but the specific mechanism is still unclear. The goal of this research was to understand the mechanism of apoptosis in cleft palate formation induced by DEX. Palatal mesenchymal cells from mouse embryos on embryonic day 13 were isolated as the experimental group, GATA-6 was silenced by GATA-6 small interfering Ribonucleic Acid (RNA). Cell Counting Kit-8, flow cytometry and Western Blot were applied to detect cell proliferation ability, cell cycle, the proportion of apoptotic cells, and the expression of apoptosis- related proteins of GATA-6 knockdown palatal mesenchymal cells. Further proteins on the BMP-2/Mitogen-activated protein kinase (MAPK) pathways were detected using Western Blot. T results showed that knockdown of GATA-6 by siRNA significantly decreased cell proliferation and increased the expression of apoptosis-related proteins. Bone morphogenetic protein-2/P38 mitogen Activated protein kinase (P38 MARK) pathway proteins decreased significantly among the GATA-6 knockdown group, DEX-cleft palate group and control +DEX groups. The results indicated that the GATA-6/BMP-2/P38 MAPK athway was involved in the apoptosis caused by GATA-6 silencing, which may be the possible mechanism of DEX inducing cleft palate.