The life cycle of platelet granules.
The life cycle of platelet granules.
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DOI：
10.12688/f1000research.13283.1
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Flaumenhaft R
中科院分区：
文献类型：
--
作者：
Sharda A;Flaumenhaft R
血小板颗粒在其含量和生命周期方面在分泌囊泡中都是独一无二的。血小板含有三种主要的颗粒类型：致密颗粒、α-颗粒和溶酶体，尽管也有其他颗粒类型的报道。致密颗粒和α-颗粒是研究最多、生理上最重要的。在转运到血小板之前，血小板颗粒在称为巨核细胞的大的多分叶细胞中形成。致密颗粒和α-颗粒的生物发生涉及共同但又不同的途径。两者均由反式高尔基网络和早期核内体形成，并在多泡体中成熟，但致密颗粒的形成需要不同于α-颗粒的运输机制。在巨核细胞体内形成后，在新生血小板释放到血流之前，两种颗粒类型都在血小板前延伸中被运输并成熟。颗粒仍然储存在循环血小板中，直到血小板激活触发其内容物的胞吐。可溶性n -乙基马来酰亚胺敏感因子附着蛋白受体（SNARE）蛋白位于颗粒和靶膜上，提供机械能，使颗粒形成和胞外分泌过程中的膜融合成为可能。这些核心融合引擎的功能由SNARE调节器控制，它指导这些SNARE相互作用的位置、时间和程度，从而产生膜融合。在这篇综述中，我们评估了血小板颗粒研究的新进展，从它们的产生到它们的胞吐。
Platelet granules are unique among secretory vesicles in both their content and their life cycle. Platelets contain three major granule types—dense granules, α-granules, and lysosomes—although other granule types have been reported. Dense granules and α-granules are the most well-studied and the most physiologically important. Platelet granules are formed in large, multilobulated cells, termed megakaryocytes, prior to transport into platelets. The biogenesis of dense granules and α-granules involves common but also distinct pathways. Both are formed from the trans-Golgi network and early endosomes and mature in multivesicular bodies, but the formation of dense granules requires trafficking machinery different from that of α-granules. Following formation in the megakaryocyte body, both granule types are transported through and mature in long proplatelet extensions prior to the release of nascent platelets into the bloodstream. Granules remain stored in circulating platelets until platelet activation triggers the exocytosis of their contents. Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, located on both the granules and target membranes, provide the mechanical energy that enables membrane fusion during both granulogenesis and exocytosis. The function of these core fusion engines is controlled by SNARE regulators, which direct the site, timing, and extent to which these SNAREs interact and consequently the resulting membrane fusion. In this review, we assess new developments in the study of platelet granules, from their generation to their exocytosis.