Normal mammary development and function in mice with Ift88 deleted in MMTV- and K14-Cre expressing cells.
Normal mammary development and function in mice with Ift88 deleted in MMTV- and K14-Cre expressing cells.
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DOI：
10.1186/2046-2530-3-4
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发表时间：
2014-03-04
期刊：
影响因子：
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通讯作者：
Serra, Rosa
中科院分区：
文献类型：
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作者：
Mitchell, Elizabeth H;Serra, Rosa
背景：初级纤毛(PC)是一种几乎存在于所有细胞类型中的非运动性微管细胞器，是多种信号通路的重要组织中心，对胚胎和出生后的发育至关重要。HH通路是研究最多的受PC调控的信号通路，它的改变影响乳腺发育以及干细胞和祖细胞数量的维持。结果：我们建立了PC缺失的小鼠模型，分别通过MMTV-CRE、K14-CRE和PRX1-CRE介导的缺失来评价PC在乳腺发育中的作用。用ROSA26证实了Cre的活性。乳腺干细胞和祖细胞在乳房生长过程中得到丰富。腺病毒-Cre介导的Ift88缺失被用来确定PC在该细胞群体中的作用。用聚合酶链式反应和免疫荧光方法证实Ift88和PC基因被破坏。PRX1-Cre；Ift88Del小鼠在青春期表现出末端芽缺陷。然而，当移植到野生型宿主体内时，这些Ift88Del腺体表现出典型的末端芽形成和正常的导管组织学，表明所观察到的表型不是乳腺固有的。此外，在MMTV-Cre-或K14-Cre；Ift88Del系中没有观察到明显的乳房发育变化。这些小鼠能够喂养和支持几窝幼崽，尽管PC被证实广泛耗尽。在乳腺培养中生长的细胞富含PC细胞，提示PC在乳腺干细胞和祖细胞上优先表达。乳腺上皮细胞中Ift88基因的缺失导致原发乳房的建立数量显著减少，而PC缺失的细胞中次生乳房的生长没有影响。结论：PC调节影响青春期早期乳房发育的系统因素。表达MMTV或K14的上皮细胞上的PC不是正常乳腺发育或功能所必需的。在乳房培养中，PC在细胞上高水平表达。PC可能是细胞在培养中建立乳房所必需的；然而，PC不是更新培养所必需的。
BACKGROUND: Primary cilia (PC) are non-motile microtubule based organelles present on almost every cell type and are known to serve as critical organizing centers for several signaling pathways crucial to embryonic and postnatal development. Alterations in the Hh pathway, the most studied signaling pathway regulated by PC, affect mammary gland development as well as maintenance of the stem and progenitor cell populations.RESULTS: We developed mouse models with deletion of PC in mammary luminal epithelial, basal epithelial, and stromal cells for evaluation of the function of PC in mammary development via MMTV-Cre, K14-Cre, and Prx1-Cre mediated deletion, respectively. The activity of Cre was confirmed using ROSA26 reporters. Mammary stem and progenitor cells were enriched through growth as mammospheres. Adenovirus-Cre mediated deletion of Ift88 was used to determine a role for PC in this population of cells. Disruption of Ift88 and PC were confirmed in using PCR and immunofluorescent methods. Prx1-Cre; Ift88Del mice demonstrated defects in terminal end buds during puberty. However, these Ift88Del glands exhibited typical terminal end bud formation as well as normal ductal histology when transplanted into wild type hosts, indicating that the phenotype observed was not intrinsic to the mammary gland. Furthermore, no discernable alterations to mammary development were observed in MMTV-Cre- or K14-Cre; Ift88Del lines. These mice were able to feed and support several litters of pups even though wide spread depletion of PC was confirmed. Cells grown in mammosphere culture were enriched for PC containing cells suggesting PC are preferentially expressed on mammary stem and progenitor cells. Deletion of Ift88 in mammary epithelial cells resulted in a significant reduction in the number of primary mammospheres established; however, there was no effect on outgrowth of secondary mammospheres in PC-depleted cells.CONCLUSIONS: PC regulate systemic factors that can affect mammary development in early puberty. PC on MMTV- or K14-expressing epithelial cells are not required for normal mammary development or function. PC are expressed at high levels on cells in mammosphere cultures. PC may be required for cells to establish mammospheres in culture; however, PC are not required for renewal of the cultures.