Role of TRPM2 and TRPV1 cation channels in cellular responses to radiation-induced DNA damage
Role of TRPM2 and TRPV1 cation channels in cellular responses to radiation-induced DNA damage
复制标题
DOI：
10.1016/j.bbagen.2013.02.020
复制
发表时间：
2013-06-01
影响因子：
3
通讯作者：
Kojima, Shuji
中科院分区：
文献类型：
--
作者：
Masumoto, Kanako;Tsukimoto, Mitsutoshi;Kojima, Shuji
背景：辐射暴露导致DNA损伤，DNA修复系统对于挽救受损细胞至关重要。尽管DNA损伤或氧化应激激活瞬时受体电位melastatin 2（TRPM 2）和香草素1（TRPV 1）阳离子通道，但尚未确定这些TRP通道是否参与辐射诱导的DNA损伤的细胞反应。方法：用γ射线（2.0戈伊）或UVB（5-10 mJ/cm（2））照射人肺癌A549细胞，观察TRPM 2和TRPV 1通道对γ射线和UVB诱导的细胞DNA损伤反应的影响。通过免疫荧光染色评价γ H2 AX病灶、ATM活化、53 BP 1积累和EGFR表达。细胞外ATP浓度用荧光素酶法测定。结果：TRPM 2和TRPV 1通道的表达下调可抑制γ射线诱导的γ H2 AX灶形成、ATM激活、53 BP 1积聚和EGFR核转位等与DNA修复相关的过程。ATP的释放，介导DNA损伤反应相关的P2 Y受体的激活，抑制预处理与过氧化氢酶或TRPM 2通道，但不TRPV 1通道的敲低。同样，TRPM 2和TRPV 1基因敲低的细胞中UVB诱导的γ H2 AX焦点形成也受到抑制，而TRPM 2基因敲低的细胞中UVB诱导的ATP释放则受到阻断，而TRPV 1基因敲低的细胞中则没有。结论：我们的结果表明，TRPM 2通道和TRPV 1通道的激活在γ射线和UVB照射诱导的DNA损伤的细胞反应中起着重要作用。我们的研究结果提供了一个新的见解TRP通道的功能，从辐射生物学的观点。(c)2013爱思唯尔有限公司版权所有。
Background: Radiation exposure causes DNA damage, and DNA repair systems are essential to rescue damaged cells. Although DNA damage or oxidative stress activates transient receptor potential melastatin 2 (TRPM2) and vanilloid 1 (TRPV1) cation channels, it has not been established whether these TRP channels are involved in cellular responses to radiation-induced DNA damage. Here, we investigated the contribution of TRPM2 and TRPV1 channels to gamma-irradiation- and UVB-induced DNA damage responses in human lung cancer A549 cells.Methods: A549 cells were irradiated with gamma-rays (2.0 Gy) or UVB (5-10 mJ/cm(2)). gamma H2AX foci, ATM activation, 53BP1 accumulation and EGFR expression were evaluated by immunofluorescence staining. Extracellular ATP concentration was measured by luciferin-luciferase assay. Knockdown of TRPM2 and TRPV1 expression was done by siRNA transfection.Results: gamma-Irradiation-induced gamma H2AX focus formation, ATM activation, 53BP1 accumulation and EGFR nuclear translocation, which are all associated with DNA repair, were suppressed by knockdown of TRPM2 and TRPV1 channels in A549 cells. Release of ATP, which mediates DNA damage response-associated activation of P2Y receptors, was suppressed by pre-treatment with catalase or knockdown of TRPM2 channel, but not TRPV1 channel. Similarly, UVB-induced gamma H2AX focus formation was suppressed in TRPM2- and TRPV1-knockdown cells, while UVB-induced ATP release was blocked in TRPM2- but not TRPV1-knockdown cells.Conclusion: Our results suggest that the activation of TRPM2 channel, which mediates ATP release, and TRPV1 channel plays significant roles in the cellular responses to DNA damage induced by y-irradiation and UVB irradiation.General significance: Our results provide a new insight into the function of TRP channels from the viewpoint of radiation biology. (c) 2013 Elsevier B.V. All rights reserved.