Abstract: Objective： To study the effects of rapamycin on the cytological properties of mouse embryonic palatal cells (MEPCs). Methods： MEPCs were isolated from E13.5 mice embryos and treated with different concentrations of rapamycin (0, 5, 10, 50, 100 nmol/L) for 0, 3, 6, 12, 24, 48 h to observe cell viability, apoptosis, migration, and osteogenic differentiation capacity, while the most effective concentration was selected. Western blot method is used to detect LC3Ⅱ and p62/SQSTM1 expression level in the concentration. Results： Compared with the control group, rapamycin promoted cell proliferation, and the effect of 10 nmol/L rapamycin was the most obvious in 6 h. After 6 h, the inhibition of rapamycin was in a time-dependent manner for MEPCs proliferation. The longer the time was, the stronger the inhibition. Compared with the control group, rapamycin inhibited cell apoptosis and 10 nmol/L rapamycin had the most obvious effect in 6 h, and after 6 h, rapamycin promoted cell apoptosis. Rapamycin significantly promoted MEPCs migration in a dose- and time-dependent manner. Rapamycin inhibited the osteogenesis of MEPCs which was shown by ALP activity, Alizarin red staining and calcium ion in a time-dependent manner; RT-PCR assays showed that the expression of bone sialoprotein and osteocalcin was lower than the control group. Compared with control group, LC3 Ⅱ expression was increased, the expression of p62/SQSTM1 was significantly decreased, rapamycin induced autophagy in a time-dependent manner. Conclusions： Rapamycin can affect the cytological properties of palatal cells, which may be related to the induction of autophagy.

Key words: rapamycin, embryonic palatal cells, autophagy, mouse