Manganese chloride-induced G0/G1 and S phase arrest in A549 cells
Manganese chloride-induced G0/G1 and S phase arrest in A549 cells
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氯化锰诱导 A549 细胞 G0/G1 和 S 期阻滞
DOI：
10.1016/j.tox.2008.05.016
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发表时间：
2008-08-19
期刊：
影响因子：
4.5
通讯作者：
Zhou, Zongcan
中科院分区：
文献类型：
--
作者：
Zhao, Peng;Zhong, Weijian;Zhou, Zongcan
在本研究中，我们研究了氯化锰（MnCl（2））对A549细胞的细胞周期进程的影响，作为锰诱导的肺毒性模型。用不同浓度的MnCl（2）（0，0.01. 0.1、0.5、1.0或2.0 mM）作用24、48或72 h。MTT法和有丝分裂指数法检测细胞增殖，流式细胞仪检测细胞凋亡。结果表明，MnCl（2）对A549细胞的增殖有明显的抑制作用，且呈剂量和时间依赖性，并能诱导A549细胞凋亡。当通过血清饥饿获得的G 0/G1细胞在10%血清存在下与0.5mM MnCl（2）孵育几个时间间隔时，观察到细胞周期进程的中断。MnCl（2）处理16 h后，细胞出现G 0/G1期阻滞，阻滞持续8 h。在G 0/G1期阻滞后，MnCl（2）在28 h将细胞阻滞于S期，并使S期阻滞持续至少4 h。此外，蛋白酶体抑制剂MG 132还能延长MnCl（2）诱导的G 0/G1阻滞时间。Western blotting结果显示，锰处理20和28 h后，细胞内Cdk 4、Cdk 2和磷酸化Cdk 2（Thr 160）水平均下降。MnCl（2）处理20 h后，Cyclin A水平下降，p53和WAF 1/p21比值升高。在锰处理20和28 h后，Cyclin D1、Cyclin E和Cdc 25 A蛋白的表达没有改变。结果表明，MnCl（2）依次诱导A549细胞发生G 0/G1期和S期阻滞，Cdk 4、Cdk 2和Cyclin A的表达减少，p53和Cdks抑制剂WAF 1/p21的表达增加可能是导致G 0/G1期阻滞的原因，Cdk 4和Cdk 2的表达减少可能是导致S期阻滞的原因。(C)2008爱思唯尔爱尔兰有限公司保留所有权利。
In the present study, we investigated the effects of manganese chloride (MnCl(2)) on cell cycle progression in A549 cells used as a model of Mn-induced lung toxicity. Cells were treated with various concentrations of MnCl(2) (0, 0.01. 0.1, 0.5, 1.0 or 2.0 mM) for 24,48 or 72 h. Cell proliferation was determined with MTT assay and mitotic index measurement and apoptosis was measured by flow cytometer. The results showed that MnCl(2) inhibited A549 cells proliferation in a dose- and time-dependent manner, and induced apoptosis in A549 cells. When G0/G1 cells obtained by serum starvation were incubated with 0.5 mM of MnCl(2) in the presence of 10% serum for several time intervals, the disruption of cell cycle progression was observed. The G0/G1 arrest was induced by MnCl(2) treatment at 16 h and the arrest maintained for 8 h. Following the G0/G1 arrest, MnCl(2) blocked the cells at S phase at 28 h and the S phase arrest maintained for at least 4 h. And moreover, proteasome inhibitor MG132 was able to prolong the duration of G0/G1 arrest induced by MnCl(2) treatment. Results of western blotting assay revealed that cellular Cdk4, Cdk2 and phospho-Cdk2 (Thr160) levels decreased in manganese-treated cells at both 20 and 28 h. In addition, the decreasing of Cyclin A level and the increasing of p53 and WAF1/p21 were also induced by MnCl(2) treatment at 20 h. The expression of Cyclin D1, Cyclin E and Cdc25A proteins was not altered in manganese-treated cells at both 20 and 28 h. Our results indicate that MnCl(2) orderly induces G0/G1 and S phase arrest in A549 cells, the decreasing of Cdk4, Cdk2 and Cyclin A, and the increasing of p53 and Cdks inhibitor WAF1/p21 might be responsible for the G0/G1 arrest, and the decreasing of Cdk4 and Cdk2 levels for the S phase arrest. (C) 2008 Elsevier Ireland Ltd. All rights reserved.