地塞米松和维生素B12干预下小鼠胚胎腭突Shh相关信号因子的研究

Study on the Shh related signal factors in mouse embryonic palatal process interfered by dexamethasone and vitamin B12

摘要:

目的： 探讨地塞米松及其拮抗剂维生素B₁₂干预妊娠关键期孕鼠后，小鼠胚胎腭突上Shh信号通路重要因子、细胞周期调控因子及初级纤毛解聚相关因子的调控及三者间的变化关系。方法： 予特定孕期C57BL/6J孕鼠腹腔注射一定剂量的生理盐水（空白对照组）、地塞米松（地塞米松组）、维生素B₁₂（维生素B₁₂组）、地塞米松+维生素B₁₂（地塞米松+维生素B₁₂组），观察妊娠17.5 d和13.5 d各组小鼠胚胎腭突融合情况；Western blot检测妊娠13.5 d各组小鼠胚胎腭突中Smo、Ptch1、Cyclin D1、Aurora A的表达变化并进行统计学分析。结果： 地塞米松延缓胚胎腭突发育而导致腭裂发生，而维生素B₁₂干预后，可部分恢复胚胎腭突发育。Western blot结果显示，与对照组相比，Ptch 1、Aurora A、Cyclin D1的表达在地塞米松组中明显降低（均P=0.000），Smo无明显改变（P=0.695）；地塞米松+维生素B₁₂组中Ptch 1、Aurora A、Cyclin D1的表达与地塞米松组相比，均不同程度上调（均P=0.000），Smo无明显改变（P=0.818）；维生素B₁₂组中各目的蛋白表达与对照组无统计学差异（P=0.879、0.399、0.645、0.168）。结论： 地塞米松影响小鼠胚胎腭突Shh下游信号传递和初级纤毛解聚，从而抑制Cyclin D1表达使小鼠胚胎腭突细胞增殖降低，维生素B₁₂可通过上调相关因子蛋白含量拮抗这一抑制效果。

Abstract:

Objective: To explore the regulation between the Shh related signal pathway cytokines, cell cycle regulator and primary cilia depolymerization factors as well as the changing relationship among them after the treatment of dexamethasone and its antagonist vitamin B₁₂intervention in the key period of pregnancy. Methods: C57BL/6J pregnant mice at specific period of pregnancy were intraperitoneally injected with a certain dose of saline (control group), dexamethasone (dexamethasone group), vitamin B₁₂ (vitamin B₁₂ group), vitamin B₁₂+dexamethasone (dexamethasone+vitamin B₁₂group), and they were observed for the fusion of embryo and palatal process in each group on 13.5 and 17.5 days of pregnancy. The expression changes of Smo, Ptch1, Cyclin D1 and Aurora A in the palatal process of mice on 13.5 days of pregnancy in each group were detected by Western blot, and analyzed statistically. Results: Dexamethasone retarded the development of the embryonic palatal process leading to cleft palate, while vitamin B₁₂intervention partially restored the development of the embryonic palatal process. Western blot results showed that, compared with the control group, the expressions of Ptch 1, Aurora A and Cyclin D1 were significantly decreased in dexamethasone group (all P=0.000), but the expression of Smo had no significant change (P=0.695). Compared with dexamethasone group, the expressions of Ptch 1, Aurora A and Cyclin D1 in dexamethasone+vitamin B₁₂group were upregulated in different degrees (all P=0.000), but the expression of Smo had no significant change (P=0.818). There was no significant difference in the expressions of each target protein between the vitamin B₁₂group and the control group (P=0.879, 0.399, 0.645, 0.168). Conclusion: Dexamethasone influences Shh downstream signal transmission and primary cilia depolymerization in the embryonic palatal process of mice, thereby inhibiting the expression of Cyclin D1 and reducing the proliferation of mouse embryonic palatal process cells. Vitamin B₁₂can antagonize the inhibitory effect by up-regulating the content of related factor proteins.