Terminally differentiated neutrophils predominantly express survivin-2α, a dominant-negative isoform of survivin
Terminally differentiated neutrophils predominantly express survivin-2α, a dominant-negative isoform of survivin
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DOI：
10.1189/jlb.0507282
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发表时间：
2008-02-01
影响因子：
5.5
通讯作者：
Kimura, Junko
中科院分区：
文献类型：
--
作者：
Hu, Huiyuan;Shikama, Yayoi;Kimura, Junko
Survivin是凋亡抑制蛋白家族的一员，最初发现于未成熟细胞和癌细胞中，但在非肿瘤性成人组织中不存在。随后鉴定出其他四种具有不同功能和定位的选择性剪接变体，表明生存素亚型的不同作用。最近发现，终末分化的中性粒细胞中的生存素的一种未指明的异构体被延长中性粒细胞寿命的细胞因子如GM-CSF和G-CSF诱导，这表明生存素在阻断中性粒细胞凋亡中的重要性。为了研究生存素抑制中性粒细胞凋亡的机制，我们试图在HL 60细胞系中通过GM-CSF/G-CSF诱导生存素，该细胞系通过全反式维甲酸和DMSO分化为中性粒细胞和新鲜分离的人中性粒细胞。抗凋亡亚型“生存素”，这是减少在分化过程中，重新诱导GM-CSF在嗜中性粒细胞样，分化HL 60。与此相反，在正常的中性粒细胞，生存素mRNA的观察自发增加后，24小时的孵育，并没有额外的海拔诱导的GM-CSF/G-CSF，发挥其抗中性粒细胞凋亡的作用，在6小时，尽管缺乏生存素诱导。PCR和Western印迹检测到Survivin-2 α，抗凋亡Survivin的显性阴性，在新鲜分离或孵育的中性粒细胞中没有其他亚型。我们的研究表明，HL 60衍生的中性粒细胞和正常的中性粒细胞之间表达的异构体和对GM-CSF的反应是不同的，其主要表达Survivin-2 α，不可能参与GM-CSF/G-CSF的凋亡抑制。
Survivin, which is a member of the inhibitor of apoptosis protein family, was found originally in immature cells and cancer cells but not in non-neoplastic adult tissues. The subsequent identification of four other alternative splice variants that possess distinct functions and localizations suggested the diverse roles of survivin isoforms. An unspecified isoform of survivin was found recently to be induced in terminally differentiated neutrophils by cytokines that prolong the neutrophil life-span, such as GM-CSF and G-CSF, suggesting the importance of survivin in blocking apoptosis in neutrophils. To examine the mechanism by which survivin inhibits neutrophil apoptosis, we attempted to induce survivin by GM-CSF/G-CSF in an HL60 cell line that was differentiated into neutrophils by all-trans retinoic acid and DMSO and freshly isolated human neutrophils. The antiapoptotic isoform "Survivin," which was decreased during differentiation, was re-induced by GM-CSF in neutrophil-like, differentiated HL60. In contrast, in normal neutrophils, survivin mRNA was observed to increase spontaneously after 24 h incubation, and no additional elevation was induced by GM-CSF/G-CSF, which exerted their antiapoptotic effects on the neutrophils in 6 h, despite the lack of survivin induction. PCR and Western blotting detected Survivin-2 alpha, a dominant-negative of antiapoptotic Survivin, with no other isoforms in the freshly isolated or incubated neutrophils. Our study revealed that the expressed isoforms and the response to GM-CSF were different between the HL60-derived and normal neutrophils, which predominantly expressed Survivin-2 alpha, not likely involved in apoptosis inhibition by GM-CSF/G-CSF.