State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Cleft Lip and Palate Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Biochemistry & Molecular Biology, University of North Dakota School of Medicine & Health Sciences, Grand Forks, ND 58203, USA.
J Zhejiang Univ Sci B. 2014 Mar;15(3):289-94. doi: 10.1631/jzus.B1300083.
The purpose of this study was to investigate the effect of vitamin B12 on palatal development by co-administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and dexamethasone (DEX). We examined the morphological and histological features of the palatal shelf and expression levels of key signaling molecules (transforming growth factor-β3 (TGF-β3) and TGF-β type I receptor (activin receptor-like kinase 5, ALK5)) during palatogenesis among a control group (Group A), TCDD+DEX exposed group (Group B), and TCDD+DEX+vitamin B12 exposed group (Group C). While we failed to find that vitamin B12 decreased the incidence of cleft palate induced by TCDD+DEX treatment, the expression levels of key signaling molecules (TGF-β3 and ALK5) during palatogenesis were significantly modulated. In TCDD+DEX exposed and TCDD+DEX+vitamin B12 exposed groups, palatal shelves could not contact in the midline due to their small sizes. Our results suggest that vitamin B12 may inhibit the expression of some cleft palate inducers such as TGF-β3 and ALK5 in DEX+TCDD exposed mice, which may be beneficial against palatogenesis to some degree, even though we were unable to observe a protective role of vitamin B12 in morphological and histological alterations of palatal shelves induced by DEX and TCDD.
本研究旨在通过联合给予 2,3,7,8-四氯二苯并对二恶英（TCDD）和地塞米松（DEX）来研究维生素 B12 对腭发育的影响。我们检查了对照组（A 组）、TCDD+DEX 暴露组（B 组）和 TCDD+DEX+维生素 B12 暴露组（C 组）在腭发生过程中腭突的形态和组织学特征，以及关键信号分子（转化生长因子-β3（TGF-β3）和 TGF-β 型 I 受体（激活素受体样激酶 5，ALK5））的表达水平。虽然我们未能发现维生素 B12 降低了 TCDD+DEX 处理引起的腭裂发生率，但关键信号分子（TGF-β3 和 ALK5）在腭发生过程中的表达水平明显受到调节。在 TCDD+DEX 暴露和 TCDD+DEX+维生素 B12 暴露组中，由于腭突较小，无法在中线接触。我们的结果表明，维生素 B12 可能抑制 DEX+TCDD 暴露小鼠中某些腭裂诱导物如 TGF-β3 和 ALK5 的表达，这可能在某种程度上有益于腭发生，尽管我们未能观察到维生素 B12 在 DEX 和 TCDD 诱导的腭突形态和组织学改变中具有保护作用。
