Role of TRPM2 and TRPV1 cation channels in cellular responses to radiation-induced DNA damage |
| |
Authors: | Kanako Masumoto Mitsutoshi Tsukimoto Shuji Kojima |
| |
Affiliation: | Department of Radiation Biosciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-0022, Japan |
| |
Abstract: | BackgroundRadiation 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 γ-irradiation- and UVB-induced DNA damage responses in human lung cancer A549 cells.MethodsA549 cells were irradiated with γ-rays (2.0 Gy) or UVB (5–10 mJ/cm2). γH2AX 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.Resultsγ-Irradiation-induced γH2AX 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 γH2AX focus formation was suppressed in TRPM2- and TRPV1-knockdown cells, while UVB-induced ATP release was blocked in TRPM2- but not TRPV1-knockdown cells.ConclusionOur 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 γ-irradiation and UVB irradiation.General significanceOur results provide a new insight into the function of TRP channels from the viewpoint of radiation biology. |
| |
Keywords: | ADPR, adenine 5&prime -diphosphoribose 2-APB, 2-aminoethoxydiphenyl borate ATM, ataxia telangiectasia mutated 53BP1, tumor suppressor p53-binding protein 1 CAP, capsaicin CPZ, capsazepine DPQ, 3,4-dihydro-5-[4-(1-piperidinyl)butoxy]-1(2H)-isoquinolinone EGFR, epithelial growth factor receptor γH2AX, phosphorylated histone variant H2AX NAD, nicotinamide adenine dinucleotide LET, linear energy transfer PARP, poly(ADP-ribose) polymerase SSB, single strand break TRPM2, transient receptor potential melastatin type 2 TRPV1, transient receptor potential vanilloid type 1 UVB, ultraviolet B |
本文献已被 ScienceDirect 等数据库收录! |
|