Mechanism of cleft palate in C57BL/6N mice induced by 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin.
10.3760/cma.j.cn112144-20220113-00014
- Author:
Yang WU
1
;
Yu Wei ZHANG
2
;
Hao Di YUE
2
;
Su Hua GAO
2
;
Zhi Dong HE
3
;
Yao CHEN
3
;
Zeng Li YU
3
;
Xiao Zhuan LIU
2
Author Information
1. Department of Stomatology, Henan Provincial People's Hospital, Zhengzhou 450003, China.
2. Clinical Medical Research Center, Henan Provincial People's Hospital, Zhengzhou 450003, China.
3. Public Health College, Zhengzhou University, Zhengzhou 450001, China.
- Publication Type:Randomized Controlled Trial, Veterinary
- MeSH:
Animals;
Bromodeoxyuridine;
Cleft Palate/genetics*;
Female;
Mice;
Mice, Inbred C57BL;
Palate/metabolism*;
Polychlorinated Dibenzodioxins/toxicity*;
Pregnancy
- From:
Chinese Journal of Stomatology
2022;57(4):397-402
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To explore the molecular mechanism of cleft palate in mice induced by 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD). Methods: The pregnant mice were randomly divided into TCDD-treated group (n=42) and control group (n=42). TCDD-treated group was given by gavage a single dose of TCDD (64 μg/kg) at 8: 00 AM on gestation day 10 (GD10) and the control group was given by gavage the isopyknic corn oil. At GD13-GD15, the fetal mice palate development was observed by HE staining. The mouse embryonic palatal mesenchymal cell proliferation was detected by 5-bromo-2-deoxyuridine (BrdU) immunofluorescence. The localization and expression of maternally expressed gene3 (MEG3) in mouse embryonic palatal mesenchymal cells was detected by situ hybridization and real-time PCR (RT-PCR). The key protein expressions of transforming growth factor-β (TGF-β)/Smad signaling pathway in mouse embryonic palatal mesenchyme were analyzed by Western blotting. The interaction of MEG3 and TGF-β receptor Ⅰ (TGF-βRⅠ) was examined by RNA binding protein immunoprecipitation (RIP). Results: At GD13 and GD14, compared with the control group, the ratio of BrdU-positive cells in the palatal mesenchyme of TCDD-treated fetuses decreased significantly (GD13, t=6.66, P=0.003; GD14, t=6.56, P=0.003). However, at GD15, the ratio of BrdU-positive cells was significantly increased (t=-5.98, P=0.004). MEG3 was mainly expressed in the nuclei of fetal mouse palatal mesenchymal cells, and the expression of MEG3 in TCDD group was significantly increased at GD13, GD14 and GD15(GD13, t=39.28, P=0.012; GD14, t=18.75, P=0.042; GD15, t=28.36, P=0.045). At GD14, TCDD decreased the levels of p-Smad2 and Smad4 in embryonic palate mesenchymal cells (p-Smad2, t=9.48, P=0.001;Smad4, t=63.10, P=0.001), whereas the expression of Smad7 was significantly increased at GD14 (t=30.77, P<0.001). The results of the RIP experiment showed that the amount of TGF-βRⅠ-bound MEG3 in mouse embryonic palatal mesenchymal cells in the TCDD group (23.940±1.301) was higher than that in the control group (8.537±1.523)(t=24.55, P<0.001). Conclusions: MEG3 is involved in the suppression of mouse embryonic palatal mesenchymal cell proliferation, functioning at least in part via interacting with the TGF-βRⅠ protein and thereby suppressing Smad signaling in the context of TCDD induced cleft palate.
