Abstract:

Objective

To study the mechanism of folic acid rescue of ATRA-induced Cleft Palate by restoring the TGF-β signal and inhibiting apoptosis.

Methods

Use palatal shelf organ culture. The experiment was divided into 3 groups， such as the FA group， ATRA group， ATRA+FA group. After 24， 48， 72 hours， the palate shelves were stained with HE， and the numbers of palatal shelf fusion were observed in each experimental group. TUNEL assay was used to detect apoptosis.Immunohistochemistry staining was used to detect the expression of caspase-9， TGF-β3 and TGFβRⅡin the palatal shelf in each experimental group.

Results

After cultured for 24， 48， 72 hours， the numbers of palatal shelf fusion were 3， 8， 8 in the FA group， and 3， 6， 7 in the ATRA+FA group， compared with nearly no fusion in ATRA group， there was a significant difference （P＜0.05）. A higher apoptosis rate and caspase-9 in MEPM cells were detected in the ATRA group than in the FA or the ATRA+FA group. Compared with the FA and the ATRA+FA group， ATRA had little effect on TGF-β3 in MEPM cells but significantly inhibited TGF-β receptorⅡ.

Conclusion

Folic acid can rescue the cultured palates to continue developing and fusing that were inhibited and resulted in cleft palate by ATRA. Apoptosis and TGF-β signaling in MEPM cells were involved in folic acid rescued ATRA-induced cleft palate.

Key words: Apoptosis, Cleft palate, Folic acid, Retinoic acid, Transforming growth factor-β signal