The release of microparticles by apoptotic cells and their effects on macrophages
The release of microparticles by apoptotic cells and their effects on macrophages
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DOI：
10.1007/s10495-005-2941-5
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发表时间：
2005-08-01
期刊：
影响因子：
7.2
通讯作者：
Pisetsky, DS
中科院分区：
文献类型：
--
作者：
Distler, JHW;Huber, LC;Pisetsky, DS
微粒是通过外源出芽从细胞膜上释放出来的小膜泡。为了阐明微粒与巨噬细胞的相互作用，测定了从Jurkat T细胞释放的微粒对RAW 264.7细胞的作用。通过差速离心分离微粒，使用膜联蛋白V和细胞表面标志物进行FACS分析以进行鉴定。细胞凋亡的各种诱导剂增加微粒从Jurkat细胞的释放高达5倍。然后将释放的微粒与RAW 264.7细胞一起培养。如共聚焦显微镜和FACS分析所示，RAW 264.7巨噬细胞通过吞噬作用清除微粒。此外，微粒以剂量依赖性方式诱导RAW 264.7细胞凋亡，膜联蛋白V阳性细胞增加多达5倍，半胱天冬酶3活性增加9倍。通过MTT试验测定的细胞增殖也降低。此外，微粒刺激从巨噬细胞释放微粒。这些作用对巨噬细胞是特异性的，因为在NIH 3T3和L929细胞中没有观察到细胞凋亡。这些发现表明，微粒可以诱导巨噬细胞进行凋亡，从而导致微粒的进一步增加。因此，从凋亡细胞释放微粒可能代表了一种新的细胞死亡放大环。
Microparticles are small membrane vesicles released from the cell membrane by exogenous budding. To elucidate the interactions of microparticles with macrophages, the effect of microparticles released from Jurkat T cells on RAW 264.7 cells was determined. Microparticles were isolated by differential centrifugation, using FACS analysis with annexin V and cell surface markers for identification. Various inducers of apoptosis increased the release of microparticles from Jurkat cells up to 5-fold. The released microparticles were then cultured with RAW 264.7 cells. As shown by confocal microscopy and FACS analysis, RAW 264.7 macrophages cleared microparticles by phagocytosis. In addition, microparticles induced apoptosis in RAW 264.7 cells in a dose-dependent manner with up to a 5-fold increase of annexin V positive cells and 9-fold increase in caspase 3 activity. Cell proliferation as determined by the MTT test was also reduced. Furthermore, microparticles stimulated the release of microparticles from macrophages. These effects were specific for macrophages, since no apoptosis was observed in NIH 3T3 and L929 cells. These findings indicate that microparticles can induce macrophages to undergo apoptosis, in turn resulting in a further increase of microparticles. The release of microparticles from apoptotic cells may therefore represent a novel amplification loop of cell death.