Ma Li1, Shi Bing2, Zheng Qian2. 1. Dept. of Stomatology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, China;State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Dept. of Cleft Lip and Palate Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China. 2. State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Dept. of Cleft Lip and Palate Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China.
Abstract
OBJECTIVE: This study aims to investigate whether dexamethasone (DEX) can down-regulate the PAR complex and disrupt the cell polarity in the palatal epithelium during palatal fusion. METHODS: Pregnant rats were randomly divided into control and DEX groups, which were injected intraperitoneally with 0.9% sodium chloride (0.1 mL) and DEX (6 mg·kg ⁻¹), respectively, every day from E10 to E12. The palatal epithelial morphology was observed using hematoxylin and eosin staining and scanning electron microscopy. Immunofluorescence staining, Western Blot analysis, and real-time polymerase chain reaction were performed to detect the expression of PAR3, PAR6, and aPKC. RESULTS: The incidence of cleft palate in DEX group (46.15%) was significantly higher than that in control group (3.92%), and the difference was statistically significant (χ2=24.335, P=0.00). DEX can also retard the growth of the palatal shelves and the short palatal shelves. The morphology and arrangement of MEE cells changed from polarized bilayer cells to nonpolarized monolayer ones. Additionally, the spherical structure decreased, which caused the cleft palate. PAR3 and PAR6 were only detected in the palatal epithelium, and aPKC was expressed in the palatal epithelium and mesenchyme. DEX can reduce the expression levels of PAR3, PAR6, and aPKC in the protein and gene levels. CONCLUSIONS: DEX can down-regulate the complex gene expression in the MEE cells, thereby destroying the cell polarity and causing cleft palate.
OBJECTIVE: This study aims to investigate whether dexamethasone (DEX) can down-regulate the PAR complex and disrupt the cell polarity in the palatal epithelium during palatal fusion. METHODS: Pregnant rats were randomly divided into control and DEX groups, which were injected intraperitoneally with 0.9% sodium chloride (0.1 mL) and DEX (6 mg·kg ⁻¹), respectively, every day from E10 to E12. The palatal epithelial morphology was observed using hematoxylin and eosin staining and scanning electron microscopy. Immunofluorescence staining, Western Blot analysis, and real-time polymerase chain reaction were performed to detect the expression of PAR3, PAR6, and aPKC. RESULTS: The incidence of cleft palate in DEX group (46.15%) was significantly higher than that in control group (3.92%), and the difference was statistically significant (χ2=24.335, P=0.00). DEX can also retard the growth of the palatal shelves and the short palatal shelves. The morphology and arrangement of MEE cells changed from polarized bilayer cells to nonpolarized monolayer ones. Additionally, the spherical structure decreased, which caused the cleft palate. PAR3 and PAR6 were only detected in the palatal epithelium, and aPKC was expressed in the palatal epithelium and mesenchyme. DEX can reduce the expression levels of PAR3, PAR6, and aPKC in the protein and gene levels. CONCLUSIONS:DEX can down-regulate the complex gene expression in the MEE cells, thereby destroying the cell polarity and causing cleft palate.
Entities:
Keywords:
PAR complex; cell polarity; cleft palate; dexamethasone; palatal shelves
Authors: A Suzuki; T Yamanaka; T Hirose; N Manabe; K Mizuno; M Shimizu; K Akimoto; Y Izumi; T Ohnishi; S Ohno Journal: J Cell Biol Date: 2001-03-19 Impact factor: 10.539