Knockdown of the nucleoporin Nup50 protects cells against ionizing radiation through enhancing DNA-PKcs-mediated DNA damage repair  

作　　者：Zhijie Wan Jingwen Gu Songyun Zhao Hang Jia Tingting Liu Yuanyuan Chen Yanyong Yang 

机构地区：[1]Department of Radiation Medicine,Faculty of Naval Medicine,Naval Medical University,Shanghai,200433,China [2]Department of Respiratory and Critical Care Medicine,the Second Naval Hospital of Southern Theater Command,Sanya,Hainan,572000,China [3]Department of Colorectal Surgery,Changhai Hospital,Naval Medical University,Shanghai,200433,China

出　　处：《Radiation Medicine and Protection》2024年第3期194-200,共7页放射医学与防护（英文）

基　　金：supported by grants from Shanghai Rising Start Program(23QA1411600);the Hainan Provincial Natural Science Foundation of China(824QN408);Three-year Action Plan for strengthening the Construction of the public health system in Shanghai(GWVI-11.2-YQ47),China.

摘　　要：Objective:To investigate the effect and mechanism of Nup50 on radiation-induced DNA damage repair to radiation and explore the potential role of Nup50 as radioprotective target.Methods:The Nup50 gene was knocked down in HUVEC cells using lentiviruses.Colony formation,CCK-8,and flow cytometry were performed to determine the viability,proliferation and apoptosis of HUVEC cells treated withγ-rays,respectively.The extent of DNA damage was evaluated by using comet assay and immu-nofluorescence staining againstγ-H2AX.In addition,we explored the role of Nup50 in DNA damage response(DDR)pathways through western blotting assay.Finally,nuclear and chromatin fractionation were performed to determine the potential molecular mechanism underlying the radiation protection function of Nup50 knockdown.Results:Nup50 knockdown increased the cellular resistance to ionizing radiation.The CCK-8 data showed that cell viability was significantly increased in the Nup50 knockdown group after radiation(t=4.23,P<0.01).The Nup50 knockdown group also showed more survived colonies(t=10.06,P<0.001),less apoptosis rate(t=3.78,P<0.05)and less unrepaired DNA damage.Furthermore,Nup50 knockdown increased radiation-activated phosphorylation levels of DNA-PKcs in HUVEC cells.Finally,the nuclear and chromatin fractionation data showed that inhibiting Nup50 increased the recruitment of DNA-PKcs to chromatin after DNA damage.Conclusions:Our findings revealed that Nup50 knockdown promoted radioresistance in normal HUVEC cells by regulating DNA-PKcs pathway,suggesting Nup50 as a potential target for radiation protection.

关 键 词：damage protective P50 

分 类 号：R81[医药卫生—放射医学]