催乳素对奶山羊移植乳腺干细胞向乳腺组织分化调控机制研究

In each lactation period，Mammary stem cells to differentiate into breast tissue under the relevant genes and hormone regulation,and the degree of differentiation determines the level of lactation, therefore, to study the differentiation of regulatory mechanisms to improve milk production of low milk production is significant. In this project team Gland stem cell co-culture promote epithelial cell proliferation and stem cells promote animal growth and tracking research of transplanted stem cell marker on, mammary gland development model is established with milk goats, The mark of mammary stem cells transplanted into the mammary gland of dairy goat model, Analysis of the impact of exogenous stem cells through regulation of prolactin levels affect the development of breast tissue in the physical level, At the cellular level, the analysis of breast stem cells in breast milk goats colonization pathways by in vivo imaging, Detection of breast stem cell paracrine level, And differentiation of progenitor cells to the law under the influence of prolactin, At the molecular level, were silenced by the prolactin receptor pathway, Analysis of changes in the abundance of prolactin receptor expression, analyze the expression and regulation of stem cell transplantation in breast milk-related functional genes; Raised prolactin transplanted mammary stem cells into mammary epithelial cells may be regulatory mechanisms, In order to improve the level of breast tissue development, Increase the amount of milk to provide a theoretical basis for research.

在每个泌乳周期，乳腺干细胞在相关基因和激素调控下分化成乳腺组织，且分化程度决定了泌乳水平，因此研究其分化调控机制对改善中低产奶牛奶产量有重要意义。项目在本团队乳腺干细胞共培养促进上皮细胞增殖、干细胞促进动物生长发育及移植干细胞标记追踪研究基础上，用奶山羊建立乳腺发育模型，将标记的乳腺干细胞移植到模型奶山羊乳腺中，在生理层面上分析外源性干细胞通过影响催乳素水平调控乳腺组织发育影响；在细胞层面上通过活体成像分析乳腺干细胞奶山羊乳腺中的定殖途径，检测乳腺干细胞旁分泌水平，以及在催乳素影响下向祖细胞的分化规律；在分子层面上通过分别沉默催乳素受体通路，分析催乳素受体表达丰度变化,分析移植乳腺干细胞对泌乳相关功能基因的表达调控；提出催乳素对移植乳腺干细胞分化为乳腺上皮细胞可能的调控机制，为提高乳腺组织发育水平，提高泌乳量提供理论研究基础。

1）分析并提出了移植外源性乳腺干细胞、血清中催乳素水平和乳腺细胞分化发育三者之间的影响。研究结果表明，向奶山羊乳腺中移植乳腺干细胞可显著增加血清中催乳素水平，在干奶期结束后，加速乳腺干细胞G0期向S期的分化，提高乳腺细胞分化数量和分化速度。.2)探明了外源植入性乳腺干细胞在移植后迁移的路径和定殖位置；研究结果表明外源性植入途径中乳腺静脉注射法优于耳静脉注射法，移植的干细胞经肺动脉循环后，可在乳腺基底部进行定殖。.3)分析了血清中PRL水平和乳腺上皮细胞 PRLR 表达丰度对乳腺细胞的增殖速度的影响；结果表明，在体外培养条件下，添加25 g/mL的 IGF-后，乳腺上皮细胞 PRLR 表达丰度极显著增加，在12h时极显著缩短了细胞周期，乳腺细胞增殖速度增加。.4)提出了奶山羊乳腺干细胞向乳腺上皮细胞分化调控 PRLR 的主要通路对乳腺干细胞增殖水平的影响途径；通过分别阻断MAPK/ERK相关通路的蛋白发现，IGF-作为一种多功能生长因子，可以通过MAPK/ERK信号通路对奶牛乳腺上皮细胞及乳成分相关基因的合成起到调控作用。.5）通过外源植入性乳腺干细胞，分析血清中 PRL、GH、E2 和 P4 水平，分析移植乳腺干细胞对乳腺上皮细胞 PRLR 表达丰度及相关功能性基因表达量的影响；外源性植入乳腺干细胞后，血清中PRL水平增加到271.02ng/ml，GH水平增加到79.72ng/ml，E2增加到29.59ng/ml，P4增加到0.86ng/ml，均显著高于对照组。移植乳腺干细胞后，上调了乳腺上皮细胞甘油三酯（TG）、α-酪蛋白（CSN1）、κ-酪蛋白（CSN3）相关基因的表达量。.6)已发表中文核心期刊 9篇；还有1篇SCI论文，3篇中文核心期刊在投。