Endothelial cell regulation of salivary gland epithelial patterning
Endothelial cell regulation of salivary gland epithelial patterning
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DOI：
10.1242/dev.142497
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发表时间：
2017-01-15
期刊：
影响因子：
4.6
通讯作者：
Larsen, Melinda
中科院分区：
文献类型：
--
作者：
Kwon, Hae Ryong;Nelson, Deirdre A.;Larsen, Melinda
在器官发育和再生过程中，脉管系统对上皮模式形成的灌注独立调节对于恢复器官功能的应用具有很大的意义。在小鼠颌下唾液腺发育过程中，脉管系统在分支形态发生过程中与上皮共同发育。然而，尚不清楚脉管系统是否对上皮有指导作用。在胚胎器官外植体中使用药理学抑制剂和 siRNA 敲低，我们确定唾液腺上皮图案形成需要 VEGFR2 依赖性信号传导。为了直接测试指导性上皮图案化中内皮细胞的需求，我们开发了一种新型的离体细胞分级/重构测定。该测定中 CD31(+) 内皮细胞的免疫耗竭证实了腺体上皮模式中对内皮细胞的需求。器官外植体中内皮细胞的耗竭或 VEGFR2 信号传导的抑制导致表达导管蛋白 K19 和 K7 的细胞异常增加，同时重建腺体终芽中的 Kit+ 祖细胞减少。向重建的腺体中添加外源内皮细胞可以恢复上皮模式，补充内皮细胞调节的间充质因子 IGFBP2 和 IGFBP3 也是如此。我们的结果表明，内皮细胞促进 Kit(+) 祖细胞的扩增并抑制早期发育的胚胎颌下唾液腺芽中的过早导管分化。
Perfusion-independent regulation of epithelial pattern formation by the vasculature during organ development and regeneration is of considerable interest for application in restoring organ function. During murine submandibular salivary gland development, the vasculature co-develops with the epithelium during branching morphogenesis; however, it is not known whether the vasculature has instructive effects on the epithelium. Using pharmacological inhibitors and siRNA knockdown in embryonic organ explants, we determined that VEGFR2-dependent signaling is required for salivary gland epithelial patterning. To test directly for a requirement for endothelial cells in instructive epithelial patterning, we developed a novel ex vivo cell fractionation/reconstitution assay. Immunodepletion of CD31(+) endothelial cells in this assay confirmed a requirement for endothelial cells in epithelial patterning of the gland. Depletion of endothelial cells or inhibition of VEGFR2 signaling in organ explants caused an aberrant increase in cells expressing the ductal proteins K19 and K7, with a reduction in Kit+ progenitor cells in the endbuds of reconstituted glands. Addition of exogenous endothelial cells to reconstituted glands restored epithelial patterning, as did supplementation with the endothelial cell-regulated mesenchymal factors IGFBP2 and IGFBP3. Our results demonstrate that endothelial cells promote expansion of Kit(+) progenitor cells and suppress premature ductal differentiation in early developing embryonic submandibular salivary gland buds.