Human placental villi contain stromal macrovesicles associated with networks of stellate cells
Human placental villi contain stromal macrovesicles associated with networks of stellate cells
复制标题
DOI：
10.1111/joa.13082
复制
发表时间：
2019-09-11
影响因子：
2.4
通讯作者：
Lewis, R. M.
中科院分区：
文献类型：
--
作者：
Palaiologou, E.;Etter, O.;Lewis, R. M.
胎盘功能对胎儿发育和建立终身健康的基础至关重要。胎盘绒毛间质是支持胎儿毛细血管和绒毛滋养细胞的结缔组织层。所有通过胎盘的营养物质也必须通过基质，但对这一区域知之甚少。本研究使用高分辨率三维成像技术来探索胎盘绒毛内该区域的结构复杂性。采用连续块面扫描电镜和共聚焦显微镜对胎盘绒毛间质进行三维成像。利用透射电子显微镜（TEM）生成高分辨率二维图像。立体学方法被用来量化基质成分的体积。三维成像发现间质细胞外囊泡，占绒毛间质体积的3.9%。这些间质细胞外囊泡呈卵形，中位长度为2750 nm（范围350-7730 nm）， TEM成像证实它们被脂质双分子层包围。59%的细胞外囊泡与成纤维细胞样星状细胞接触，这些囊泡明显大于未观察到接触的囊泡。这些星状细胞形成局部网络，在接触点观察到粘附连接。本研究表明，绒毛间质含有细胞外大泡，比以前在组织或血浆中描述的任何大泡都要大得多。绒毛间质中这些大泡的大小和丰度突出了细胞外泡生物学的多样性及其在结缔组织中的作用。
Placental function is essential for fetal development and establishing the foundations for lifelong health. The placental villous stroma is a connective tissue layer that supports the fetal capillaries and villous trophoblast. All the nutrients that cross the placenta must also cross the stroma, and yet little is known about this region. This study uses high-resolution three-dimensional imaging to explore the structural complexity of this region within the placental villi. Serial block-face scanning electron microscopy and confocal microscopy were used to image the placental villous stroma in three-dimensions. Transmission electron microscopy (TEM) was used to generate high resolution two-dimensional images. Stereological approaches were used to quantify volumes of stromal constituents. Three-dimensional imaging identified stromal extracellular vesicles, which constituted 3.9% of the villous stromal volume. These stromal extracellular vesicles were ovoid in shape, had a median length of 2750 nm (range 350-7730 nm) and TEM imaging confirmed that they were bounded by a lipid bilayer. Fifty-nine per cent of extracellular vesicles were in contact with a fibroblast-like stellate cell and these vesicles were significantly larger than those where no contact was observed. These stellate cells formed local networks with adherent junctions observed at contact points. This study demonstrates that the villous stroma contains extracellular macrovesicles which are considerably larger than any previously described in tissue or plasma. The size and abundance of these macrovesicles in the villous stroma highlight the diversity of extracellular vesicle biology and their roles within connective tissues.