Stimulated release of intraluminal vesicles from Weibel-Palade bodies
Stimulated release of intraluminal vesicles from Weibel-Palade bodies
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DOI：
10.1182/blood-2018-09-874552
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发表时间：
2019-06-20
期刊：
影响因子：
20.3
通讯作者：
Carter, Tom
中科院分区：
文献类型：
--
作者：
Streetley, James;Fonseca, Ana-Violeta;Carter, Tom
韦贝尔-帕拉德小体（WPBs）是含有血管性血友病因子和p选择素的分泌颗粒，这两种分子分别调节止血和炎症。CD63/LAMP3存在于WPBs的限制膜中，导致它们被分类为溶酶体相关细胞器。许多溶酶体相关细胞器含有富含CD63的腔内囊泡（ILVs），这些囊泡在细胞活化过程中分泌到细胞外环境中，介导细胞间的通讯。到目前为止，还没有关于wpb包含或释放ilv的报告。通过光镜和活细胞成像，我们发现CD63在WPBs的微结构域中富集。细胞外抗体循环研究表明，WPB微域内的CD63可来源于质膜。通过冷冻水合内皮细胞的低温电子断层扫描，我们确定了内囊泡是WPB管腔的新结构特征。通过活细胞荧光显微镜，我们直接观察到EGFP-CD63 ILVs作为单个WPBs的离散颗粒的胞外释放。WPB胞吐作用为内皮细胞刺激过程中ILVs的释放提供了一条新的途径。
Weibel-Palade bodies (WPBs) are secretory granules that contain von Willebrand factor and P-selectin, molecules that regulate hemostasis and inflammation, respectively. The presence of CD63/LAMP3 in the limiting membrane of WPBs has led to their classification as lysosome-related organelles. Many lysosome-related organelles contain intraluminal vesicles (ILVs) enriched in CD63 that are secreted into the extracellular environment during cell activation to mediate intercellular communication. To date, there are no reports that WPBs contain or release ILVs. By light microscopy and live-cell imaging, we show that CD63 is enriched in microdomains within WPBs. Extracellular antibody recycling studies showed that CD63 in WPB microdomains can originate from the plasma membrane. By cryo-electron tomography of frozen-hydrated endothelial cells, we identify internal vesicles as novel structural features of the WPB lumen. By live-cell fluorescence microscopy, we directly observe the exocytotic release of EGFP-CD63 ILVs as discrete particles from individual WPBs. WPB exocytosis provides a novel route for release of ILVs during endothelial cell stimulation.