小鼠下颌下腺发育中转化生长因子β受体的表达

背景：小鼠的下颌下腺是研究唾液腺的发育的良好模型,转化生长因子β是器官发育和疾病中重要的生长因子,但是在下颌下腺中转化生长因子β受体的表达以及作用机制至今并不明确。 目的：观察胚胎小鼠下颌下腺发育过程中转化生长因子βⅠ型受体和Ⅱ型受体以及p-ERK1/2的表达,揭示转化生长因子β在小鼠涎腺发育中的作用。 方法：取C57BL/6J小鼠胚胎期第14.5天的标本,使用转化生长因子βⅠ型受体和Ⅱ型受体以及p-ERK1/2抗体,对小鼠的下颌下腺进行免疫组化染色。取新生小鼠标本,大体观察下颌下腺,并且使用苏木精-伊红染色观察其形态。 结果与结论：①小鼠出生时,下颌下腺位于下颌骨下方;苏木精-伊红染色发现小鼠下颌下腺的腺泡、导管和闰管细胞也已经分化完成。②在胚胎期第14.5天,转化生长因子βⅠ型和Ⅱ型受体在腺泡上皮和导管上皮内高表达,而腺体上皮细胞外的间充质没有表达。③p-ERK1/2主要也是表达在下颌下腺的上皮细胞中,与转化生长因子βⅠ型受体和Ⅱ型受体在下颌下腺中的表达基本一致。说明在小鼠下颌下腺的发育过程中,转化生长因子β蛋白可能通过与上皮细胞表面的受体结合,激活ERK信号通路来调节涎腺腺泡和导管的发育。

Expression of transforming growth factor beta receptor during mouse submandibular gland development

BACKGROUND:The submandibular gland in mice is a typical study model for salivary development. Transforming growth factor beta is an essential growth factor during development and diseases. Till now the receptor of transforming growth factor beta and its function during salivary development has not been known well. OBJECTIVE:To observe the expression of transforming growth factor beta typeⅠreceptor (Tgfbr1), transforming growth factor beta type Ⅱ receptor (Tgfbr2) and phospholated extracellular signal-regulated kinase 1/2 in mouse submandibular glands in order to uncover the mechanism of transforming growth factor beta signaling in gland development. METHODS:Male and female C57BL/6J mice were mated to get embryos at embryonic day 14.5 (E14.5) and newborn stage. The samples were fixed in 4% paraformaldehyde and processed into paraffin embedded serial sections. The sections were stained with hematoxylin and eosin and immunohistochemistry by the antibodies of Tgfbr1, Tgfbr2 and phospholated extracellular signal-regulated kinase 1/2 using standard procedures. RESULTS AND CONCLUSION:(1) At newborn stage, the submandibular gland was located under the mandible in mice. The submandibular gland alveolus, gland duct including intercalary duct developed well. (2) At E14.5, Tgfbr1 and Tgfbr2 were expressed strongly in the submandibular glands epithelium, but not in the mesenchyme. (3) Expression of phospholated extracellular signal-regulated kinase 1/2, similar to Tgfbr1 and Tgfbr2, was only detected in the epithelium. Therefore, transforming growth factor beta might regulate extracellular signal-regulated kinase signaling in epithelial cells of the submandibular glands in order to control the submandibular gland development.