Argonaute 2 complexes selectively protect the circulating microRNAs in cell-secreted microvesicles.
Argonaute 2 complexes selectively protect the circulating microRNAs in cell-secreted microvesicles.
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DOI：
10.1371/journal.pone.0046957
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Zen K
中科院分区：
文献类型：
--
作者：
Li L;Zhu D;Huang L;Zhang J;Bian Z;Chen X;Liu Y;Zhang CY;Zen K
细胞分泌的miRNAs是高度稳定的，可以作为各种疾病的生物标志物和细胞间通讯的信号分子。然而，循环miRNA稳定性的机制仍然不完全清楚。在这里，我们表明Argonaute 2（Ago 2）复合物和微泡（MV）分别为细胞分泌的MV中的miRNA提供特异性和非特异性保护。首先，MV包裹的miRNA对RNaseA的抗性既依赖于MV的完整囊泡结构，又依赖于蛋白酶敏感性。第二，使用与人miR-16互补的探针的免疫沉淀测定，主要位于MV中的miRNA，对RNaseA显示出强烈的蛋白酶敏感性抗性，将Ago 2鉴定为主要的miR-16相关蛋白。与无蛋白的miR-16相比，Ago 2相关的miR-16对RNaseA具有剂量和时间依赖性。第三，当用色氨酸破坏miR-16/Ago 2复合物时，miR-16对RNaseA的抗性降低。相反，当在细胞凋亡期间增加miR-16与Ago 2复合物的缔合时，尽管miR-16和Ago 2的总量保持不变，但MV中miR-16对RNaseA的抗性增强。在全反式维甲酸（ATRA）诱导的早幼粒细胞HL 60细胞分化过程中，观察到miR-223/Ago 2缔合增加与miR-223对RNaseA的抗性之间存在类似的相关性。总之，miRNA与Ago 2复合物的结合（与细胞功能状态相关的事件）在稳定细胞分泌的MV中的循环miRNA中起关键作用。
Cell-secreted miRNAs are highly stable and can serve as biomarkers for various diseases and signaling molecules in intercellular communication. The mechanism underlying the stability of circulating miRNAs, however, remains incompletely understood. Here we show that Argonaute 2 (Ago2) complexes and microvesicles (MVs) provide specific and non-specific protection for miRNA in cell-secreted MVs, respectively. First, the resistance of MV-encapsulated miRNAs to RNaseA was both depended on intact vesicular structure of MVs and protease-sensitive. Second, an immunoprecipitation assay using a probe complementary to human miR-16, a miRNA primarily located in the MVs and showed a strong, protease-sensitive resistance to RNaseA, identified Ago2 as a major miR-16-associated protein. Compared with protein-free miR-16, Ago2-associated miR-16 was resistant to RNaseA in a dose- and time-dependent fashion. Third, when the miR-16/Ago2 complex was disrupted by trypaflavine, the resistance of miR-16 to RNaseA was decreased. In contrast, when the association of miR-16 with the Ago2 complexes was increased during cell apoptosis, although the total amount of miR-16 and Ago2 remained unchanged, the resistance of miR-16 to RNaseA in the MVs was enhanced. A similar correlation between the increase of miR-223/Ago2 association and the resistance of miR-223 against RNaseA was observed during all trans retinoic acid (ATRA)-induced cell differentiation of promyelocytic HL60 cells. In conclusion, the association of miRNAs with Ago2 complexes, an event that is linked to cell functional status, plays a critical role in stabilizing the circulating miRNAs in cell-secreted MVs.
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影响因子：
3.7
作者：
Collino F;Deregibus MC;Bruno S;Sterpone L;Aghemo G;Viltono L;Tetta C;Camussi G
通讯作者：
Camussi G
影响因子：
20.3
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影响因子：
64.8
作者：
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通讯作者：
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影响因子：
3.7
作者：
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通讯作者：
Marsh, Clay B.
影响因子：
21.3
作者：
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通讯作者：
Breakefield, Xandra O.