p53 Plays an important role in cell fate determination after exposure to microcystin-LR.
p53 Plays an important role in cell fate determination after exposure to microcystin-LR.
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DOI：
10.1289/ehp.1001899
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发表时间：
2010-09
影响因子：
10.4
通讯作者：
Takeuchi T
中科院分区：
文献类型：
--
作者：
Takumi S;Komatsu M;Furukawa T;Ikeda R;Sumizawa T;Akenaga H;Maeda Y;Aoyama K;Arizono K;Ando S;Takeuchi T
微囊藻毒素lr是一种环七肽，具有抑制丝氨酸/苏氨酸蛋白磷酸酶PP1和PP2A的能力，因此表现出急性肝细胞毒性。此外，微囊藻毒素lr还能诱导细胞增殖，从而在肝细胞中产生促肿瘤活性。然而，微囊藻毒素- lr治疗后调节细胞死亡和增殖平衡的机制尚不清楚。我们研究了转录因子p53，以及微囊藻毒素lr的肝脏摄取转运体，有机阴离子转运多肽1B3 (OATP1B3)，对细胞对微囊藻毒素lr暴露的反应的贡献。我们使用稳定转染了SLCO1B3 （HEK293- oatp1b3）的HEK293人胚胎肾细胞，通过免疫印迹和实时逆转录酶聚合酶链反应技术分析了细胞内对微囊素- lr的信号反应。此外，我们利用3-（4,5-二甲基噻唑-2-基）-2,5-二苯基溴化四唑（MTT）试验分析了p53抑制剂聚氟乙烯-α对p53功能的抑制和p53 mRNA的敲低对微囊藻毒素- lr细胞毒性的影响。微囊藻毒素- lr诱导HEK293-OATP1B3细胞中p53的磷酸化和积累，导致p53转录靶蛋白p21和7 in absentia homolog 1 （siah-1）的表达上调。此外，微囊蛋白lr通过磷酸化Akt和糖原合成酶激酶3β激活Akt信号。虽然Akt信号被激活，但50 nM微囊藻素- lr处理24小时后，p53的积累导致细胞凋亡。用聚氰菊酯-α抑制p53转录因子活性和用小发夹RNA敲低p53均可减弱HEK293-OATP1B3细胞对微囊藻毒素- lr的敏感性。本研究证明了p53在暴露于微囊藻毒素- lr后调控细胞命运中的重要性。我们的研究结果表明，在p53失活（包括p53突变）的条件下，长期暴露于低剂量微囊藻毒素lr可能通过激活Akt信号导致细胞增殖。本研究结果可能有助于微囊藻毒素- lr中毒的化学预防和化学治疗方法的发展。
Microcystin-LR, a cyclic heptapeptide, possesses the ability to inhibit the serine/threonine protein phosphatases PP1 and PP2A and, consequently, exhibits acute hepatocytotoxicity. Moreover, microcystin-LR induces cellular proliferation, resulting in tumor-promoting activity in hepatocytes. However, mechanisms that regulate the balance between cell death and proliferation after microcystin-LR treatment remain unclear. We examined the contribution of the transcription factor p53, as well as that of the hepatic uptake transporter for microcystin-LR, organic anion transporting polypeptide 1B3 (OATP1B3), to the cellular response to microcystin-LR exposure. We analyzed intracellular signaling responses to microcystin-LR by immunoblotting and real-time reverse-transcriptase polymerase chain reaction techniques using HEK293 human embryonic kidney cells stably transfected with SLCO1B3 (HEK293-OATP1B3). In addition, we analyzed the effect of attenuation of p53 function, via the p53 inhibitor pifithrin-α, and knockdown of p53 mRNA on the cytotoxicity of microcystin-LR using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Microcystin-LR induced the phosphorylation and accumulation of p53 in HEK293-OATP1B3 cells, which resulted in up-regulation of the expression of p53 transcript targets, including p21 and seven in absentia homolog 1 (siah-1). In addition, microcystin-LR activated Akt signaling through the phosphorylation of Akt and glycogen synthase kinase 3β. Although Akt signaling was activated, the accumulation of p53 led cells to apoptosis after treatment with 50 nM microcystin-LR for 24 hr. Both pharmacological inhibition of transcription factor activity of p53 by pifithrin-α and knockdown of p53 with small hairpin RNA attenuated the susceptibility of HEK293-OATP1B3 cells to microcystin-LR. This study demonstrates the importance of p53 in the regulation of cell fate after exposure to microcystin-LR. Our results suggest that, under conditions of p53 inactivation (including p53 mutation), chronic exposure to low doses of microcystin-LR may lead to cell proliferation through activation of Akt signaling. Results of this study may contribute to the development of chemoprevention and chemotherapeutic approaches to microcystin-LR poisoning.
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影响因子：
8.8
作者：
Chong, MWK;Gu, KD;Fong, WF
通讯作者：
Fong, WF
影响因子：
64.8
作者：
Green, Douglas R.;Kroemer, Guido
通讯作者：
Kroemer, Guido
影响因子：
4.8
作者：
Ding, VW;Chen, RH;McCormick, F
通讯作者：
McCormick, F
DOI：
10.1006/bbrc.2002.6453
发表时间：
2002-02-22
影响因子：
3.1
作者：
Ding, WX;Shen, HM;Ong, CN
通讯作者：
Ong, CN
影响因子：
3.7
作者：
Bordonaro, Michael;Lazarova, Darina L.;Sartorelli, Alan C.
通讯作者：
Sartorelli, Alan C.