Protein kinase CK2 regulates cytoskeletal reorganization during ionizing radiation-induced senescence of human mesenchymal stem cells.
Protein kinase CK2 regulates cytoskeletal reorganization during ionizing radiation-induced senescence of human mesenchymal stem cells.
复制标题
蛋白激酶CK2在电离辐射引起的人间充质干细胞衰老过程中调节细胞骨架重组。
DOI：
10.1158/0008-5472.can-09-1976
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发表时间：
2009-10-15
期刊：
影响因子：
11.2
通讯作者：
Jang DJ
中科院分区：
文献类型：
--
作者：
Wang D;Jang DJ
人类间充质干细胞（hMSC）对于组织再生至关重要。hMSC如何对遗传毒性应激作出反应并可能导致衰老和癌症仍有待研究。我们证明，电离辐射诱导细胞衰老的hMSC在一段时间内的10天，显示了一个关键的过渡之间的第3天和第6天。衰老相关β-半乳糖苷酶（SA-β-gal）染色、关键细胞周期调节因子（视网膜母细胞瘤（Rb）蛋白、p53、p21 waf 1/Cip 1和p16 INK 4A）的蛋白表达谱以及衰老相关分泌表型（SASP）（IL-8、IL-12、GRO和MDC）证实了这一点。我们观察到显着的细胞骨架重组hMSC通过减少肌球蛋白-10，肌球蛋白-9的重新分配，和profilin-1的分泌。使用基于SILAC的磷酸化蛋白质组学方法，我们检测到肌球蛋白-9在Ser 1943磷酸化的显着减少，与其重新分布一致。重要的是，通过细胞渗透性抑制剂（（4，5，6，7-四溴-1H-苯并三唑（TBB）和2-二甲氨基-4，5，6，7-四溴-1H-苯并咪唑（DMAT））的治疗，以及使用RNA干扰的基因敲除，我们确定了CK 2，一种负责肌球蛋白-9磷酸化的激酶，在Ser 1943，作为一个关键因素，有助于辐射诱导的hMSC衰老。我们发现单独敲低CK 2催化亚基CK 2 α和CK 2 α′可诱导hMSC衰老。然而，只有CK 2 α的敲低导致类似于辐射诱导衰老的形态表型。这些结果表明，CK 2 α和CK 2 α′在hMSC衰老过程中发挥不同的作用，其相对表达可能是一种新的CK 2活性调节机制。
Human mesenchymal stem cells (hMSC) are critical for tissue regeneration. How hMSC respond to genotoxic stresses and potentially contribute to aging and cancer remain underexplored. We demonstrated that ionizing radiation induced cellular senescence of hMSC over a period of 10 days, showing a critical transition between day 3 and day 6. This was confirmed by senescence-associated beta-galactosidase (SA-β-gal) staining, protein expression profiles of key cell cycle regulators (retinoblastoma (Rb) protein, p53, p21waf1/Cip1, and p16INK4A), and senescence-associated secretory phenotypes (SASPs) (IL-8, IL-12, GRO, and MDC). We observed dramatic cytoskeletal reorganization of hMSC through reduction of myosin-10, redistribution of myosin-9, and secretion of profilin-1. Using a SILAC-based phosphoproteomics method, we detected significant reduction of myosin-9 phosphorylation at Ser1943, coinciding with its redistribution. Importantly, through treatment with cell permeable inhibitors ((4,5,6,7-tetrabromo-1H-benzotriazole (TBB) and 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole (DMAT)), and gene knockdown using RNA interference, we identified CK2, a kinase responsible for myosin-9 phosphorylation at Ser1943, as a key factor contributing to the radiation-induced senescence of hMSC. We showed that individual knockdown of CK2 catalytic subunits CK2α and CK2α′ induced hMSC senescence. However, only knockdown of CK2α resulted in morphological phenotypes resembling those of radiation-induced senescence. These results suggest that CK2α and CK2α′ play differential roles in hMSC senescence progression, and their relative expression might represent a novel regulatory mechanism for CK2 activity.