Guangdong Provincial Key Laboratory of Stomatology, Sun Yat‑sen University, Guangzhou, Guangdong 510055, P.R. China.
Mol Med Rep. 2017 Nov;16(5):5915-5923. doi: 10.3892/mmr.2017.7327. Epub 2017 Aug 22.
The current study was designed to elucidate the mechanism of retinol binding protein 4 (RBP4) in cleft palate induced by all‑trans retinoic acid (atRA). To establish a cleft palate model in C57BL/6J mice, pregnant mice were administered atRA (100 mg/kg) by gavage at the tenth embryonic stage (E10.0). Control groups were given the equivalent volume of corn oil. Pregnant mice were dissected at E12.5, E13.5 and E14.5 to obtain the embryonic palates. The expression levels of RBP4 in the embryonic palatal mesenchyme (EPM) were determined by immunohistochemistry, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blotting. Human embryonic palatal mesenchymal cells were exposed to atRA to detect the variation in RBP4 induced by atRA in vitro. Small interfering RNA was used to suppress the expression of RBP4, and a plasmid overexpressing RBP4 was used to examine upregulated expression. The cell counting kit‑8 assay was used to evaluate the effect of RBP4 on cell proliferation. The expression levels of p27 and cyclin D1 were determined by RT‑qPCR and western blotting, while the expression levels of extracellular signal‑related kinase (ERK) 1/2 and protein kinase B (AKT) were assessed by western blotting. At E14.5, RBP4 was strongly expressed in the EPM, while it was downregulated following atRA treatment, which induced cleft palate in vivo. In vitro experiments indicated that atRA suppressed the expression of RBP4 and altered the expression of p27 and cyclin D1 to cause growth inhibition. Knockdown of RBP4 resulted in decreased expression of cyclin D1 and increased p27, and suppressed proliferation. Overexpression of RBP4 reversed the inhibitory effect of atRA and promoted proliferation via the ERK1/2 and AKT signaling pathways. These results suggested that RBP4 was involved in cleft palate induced by atRA and it can be suppressed by atRA to cause growth inhibition in the embryonic palate.
本研究旨在阐明全反式视黄酸(atRA)诱导腭裂形成过程中视黄醇结合蛋白 4(RBP4)的作用机制。通过灌胃给予妊娠第 10 天(E10.0)的 C57BL/6J 孕鼠 100mg/kg 的 atRA 建立腭裂模型,对照组给予等体积玉米油。在 E12.5、E13.5 和 E14.5 时剖取胚胎腭,免疫组化、逆转录-定量聚合酶链反应(RT-qPCR)和 Western blot 检测胚胎腭间质中 RBP4 的表达水平。体外给予人胚胎腭间充质细胞 atRA 以检测 atRA 诱导的 RBP4 变化。用小干扰 RNA 抑制 RBP4 的表达,过表达 RBP4 的质粒检测上调表达。细胞计数试剂盒-8 检测 RBP4 对细胞增殖的影响。通过 RT-qPCR 和 Western blot 检测 p27 和细胞周期蛋白 D1 的表达水平,Western blot 检测细胞外信号调节激酶(ERK)1/2 和蛋白激酶 B(AKT)的表达水平。在 E14.5 时,RBP4 在 EPM 中强烈表达,而在 atRA 处理后表达下调,导致体内腭裂形成。体外实验表明,atRA 抑制 RBP4 的表达,并改变 p27 和细胞周期蛋白 D1 的表达,导致生长抑制。敲低 RBP4 导致细胞周期蛋白 D1 表达减少和 p27 增加,并抑制增殖。过表达 RBP4 逆转了 atRA 的抑制作用,并通过 ERK1/2 和 AKT 信号通路促进增殖。这些结果表明,RBP4 参与了 atRA 诱导的腭裂形成,它可以被 atRA 抑制,导致胚胎腭生长抑制。