MicroRNA-30 inhibits antiapoptotic factor Mcl-1 in mouse and human hematopoietic cells after radiation exposure.
MicroRNA-30 inhibits antiapoptotic factor Mcl-1 in mouse and human hematopoietic cells after radiation exposure.
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DOI：
10.1007/s10495-016-1238-1
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发表时间：
2016-06
期刊：
影响因子：
--
通讯作者：
Xiao M
中科院分区：
文献类型：
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作者：
Li XH;Ha CT;Xiao M
我们先前报道了microRNA-30（miR-30）的表达是由辐射诱导的小鼠和人类造血细胞中的促炎因子IL-1β和NF κ B激活启动的。然而，miR-30的下游效应子及其在辐射诱导的细胞死亡中的具体作用还不清楚。在本研究中，我们评估了辐射对体内小鼠和体外人造血细胞中miR-30表达和内在凋亡途径Bcl-2家族因子激活的影响。将CD 2F 1小鼠和人CD 34+细胞暴露于不同剂量的γ辐射。除了存活研究之外，在照射后4小时和1、3和4天收集小鼠血液、骨髓（BM）和脾细胞以及人CD 34+细胞，以确定凋亡和应激反应信号。我们的研究结果表明，小鼠血清miR-30，骨髓中的DNA损伤标记物γ-H2 AX，以及骨髓和/或脾细胞中Bim，Bax和巴克的表达，细胞色素c的释放，以及caspase-3和-7的活化均以辐射剂量依赖性方式上调。抗凋亡因子Mcl-1的显着下调，而Bcl-2的变化较小或在照射的小鼠细胞和人CD 34+细胞不变。此外，在Mcl-1 mRNA的3′ UTR处发现了一个可能的miR-30结合位点。miR-30通过与其靶序列结合直接抑制Mcl-1的表达，这通过荧光素酶报告基因测定以及在miR-30敲低的CD 34+细胞中Mcl-1不受辐射抑制的发现来证明。Bcl-2表达不受miR-30的影响。我们的数据表明miR-30通过直接靶向造血细胞中的Mcl-1在辐射诱导的细胞凋亡中起关键作用。
We previously reported that microRNA-30 (miR-30) expression was initiated by radiation-induced proinflammatory factor IL-1β and NFkB activation in mouse and human hematopoietic cells. However, the downstream effectors of miR-30 and its specific role in radiation-induced cell death are not well understood. In the present study, we evaluated effects of radiation on miR-30 expression and activation of intrinsic apoptotic pathway Bcl-2 family factors in in vivo mouse and in vitro human hematopoietic cells. CD2F1 mice and human CD34+ cells were exposed to different doses of gamma-radiation. In addition to survival studies, mouse blood, bone marrow (BM) and spleen cells and human CD34+ cells were collected at 4 h, and 1, 3 and 4 days after irradiation to determine apoptotic and stress response signals. Our results showed that mouse serum miR-30, DNA damage marker γ-H2AX in BM, and Bim, Bax and Bak expression, cytochrome c release, and caspase-3 and -7 activation in BM and/or spleen cells were upregulated in a radiation dose-dependent manner. Antiapoptotic factor Mcl-1 was significantly downregulated, whereas Bcl-2 was less changed or unaltered in the irradiated mouse cells and human CD34+ cells. Furthermore, a putative miR-30 binding site was found in the 3′ UTR of Mcl-1 mRNA. miR-30 directly inhibits the expression of Mcl-1 through binding to its target sequence, which was demonstrated by a luciferase reporter assay, and the finding that Mcl-1 was uninhibited by irradiation in miR-30 knockdown CD34+ cells. Bcl-2 expression was not affected by miR-30. Our data suggest miR-30 plays a key role in radiation-induced apoptosis through directly targeting Mcl-1in hematopoietic cells.