Zhang Ping, Wang Guang, Lin Zhuangling, Wu Yushi, Zhang Jing, Liu Meng, Lee Kenneth Ka Ho, Chuai Manli, Yang Xuesong
Key Laboratory for Regenerative Medicine of the Ministry of Education, Division of Histology & Embryology, Medical College, Jinan University, Guangzhou 510632, China.
Key Laboratory for Regenerative Medicine of the Ministry of Education, School of Biomedical Sciences, Chinese University of Hong Kong, Shatin, Hong Kong.
Toxicol Lett. 2017 Nov 5;281:53-64. doi: 10.1016/j.toxlet.2017.09.010. Epub 2017 Sep 14.
Excess alcohol consumption during pregnancy could lead to fetal alcohol syndrome (FAS). However, the molecular mechanism leading to craniofacial abnormality, a feature of FAS, is still poorly understood. The cranial neural crest cells (NCCs) contribute to the formation of the craniofacial bones. Therefore, NCCs exposed to ethanol was investigated - using chick embryos and in vitro explant culture as experimental models. We demonstrated that exposure to 2% ethanol induced craniofacial defects, which includes parietal defect, in the developing chick fetus. Immunofluorescent staining revealed that ethanol treatment downregulated Ap-2ɑ, Pax7 and HNK-1 expressions by cranial NCCs. Using double-immunofluorescent stainings for Ap-2ɑ/pHIS3 and Ap-2ɑ/c-Caspase3, we showed that ethanol treatment inhibited cranial NCC proliferation and increased NCC apoptosis, respectively. Moreover, ethanol treatment of the dorsal neuroepithelium increased Laminin, N-Cadherin and Cadherin 6B expressions while Cadherin 7 expression was repressed. In situ hybridization also revealed that ethanol treatment up-regulated Cadherin 6B expression but down-regulated slug, Msx1, FoxD3 and BMP4 expressions. In summary, our experimental results demonstrated that ethanol treatment interferes with the production of cranial NCCs by affecting the proliferation and apoptosis of these cells. In addition, ethanol affected the delamination, epithelial-mesenchymal transition (EMT) and cell migration of cranial NCCs, which may have contributed to the etiology of the craniofacial defects.
孕期过量饮酒可能导致胎儿酒精综合征（FAS）。然而，导致FAS特征之一颅面异常的分子机制仍知之甚少。颅神经嵴细胞（NCCs）参与颅面骨的形成。因此，以鸡胚和体外植块培养为实验模型，对暴露于乙醇的NCCs进行了研究。我们证明，暴露于2%乙醇会导致发育中的鸡胎儿出现颅面缺陷，包括顶骨缺陷。免疫荧光染色显示，乙醇处理会下调颅神经嵴细胞中Ap-2ɑ、Pax7和HNK-1的表达。通过对Ap-2ɑ/pHIS3和Ap-2ɑ/c-Caspase3进行双重免疫荧光染色，我们表明乙醇处理分别抑制了颅神经嵴细胞的增殖并增加了其凋亡。此外，对背侧神经上皮进行乙醇处理会增加层粘连蛋白、N-钙黏蛋白和钙黏蛋白6B的表达，而钙黏蛋白7的表达则受到抑制。原位杂交还显示，乙醇处理上调了钙黏蛋白6B的表达，但下调了蛞蝓蛋白、Msx1、FoxD3和骨形态发生蛋白4的表达。总之，我们的实验结果表明，乙醇处理通过影响颅神经嵴细胞的增殖和凋亡来干扰其产生。此外，乙醇影响了颅神经嵴细胞的分层、上皮-间质转化（EMT）和细胞迁移，这可能是颅面缺陷病因的一部分。
