Abstract:

Objective

To establish mouse palatal organ culture model and investigate the mechanism of all-trans retinoic acid （atRA） inducing cleft palate.

Methods

The mouse palate organ culture model was established according to the previous studies.3.0 μmol/L atRA（experimental group） or absolute ethanol （control group） was directly added to the culture medium.For whole mount palate observation and apoptosis detaction， the cultured palates were determined by acridine orange（AO） and TUNNEL.The immunohistochemistry analysis of Smad 2/3 was performed， too.

Results

The mouse palatal organ culture model was successfully founded in vitro and fusion rate was 82.30%（93/113）.After palate shelves contact， apoptosis was detected in the medial edge epithelial （MEE）， but only in the adhered region.Smad 2/3-positive cells were constantly observed in the medial edge seam （MES） after 24 h' culture， while few positive cells were observed in 48 h.If contact of palate shelf was avoided， the apoptosis in MEE disappeared.Apoptosis in MEE could not be observed when 3.0 μmol/L atRA was added into the culture medium.The fusion of palate shelves was disturbed and the MES could not disappear.Moreover， Smad 2/3-positive cells could not be detected in MES after 3.0 μmol/L atRA treated.

Conclusions

Mouse palatal organ culture model was successfully founded in vitro.It was certificated that Smad2/3 was involved in the atRA-induced disturbing of palate fusion in vitro.

Key words: All-trans retinoic acid, Cleft palate, Embryonic palate medial edge epithelial cells, Apoptosis, Smad2/3