miR-769-5p在急性中长波紫外线旁观者效应中的作用

The Role of miR-769-5p in the Acute UVA/UVB-radiation Induced Bystander Effect

目的 探讨miR-769-5p在急性中长波紫外线旁观者效应中的作用。方法 用miR-769-5p mimics转染人真皮成纤维细胞,培养24 h后取培养上清孵育旁观者细胞,培养48 h后检测细胞增殖率、凋亡率及氧化损伤水平。预先用miR-769-5p inhibitor下调细胞中miR-769-5p的表达,24 h后与辐射条件培养基共孵育,48 h后检测细胞的增殖率、凋亡率及氧化损伤水平。结果 miR-769-5p mimics可上调细胞中miR-769-5p的表达,过表达的miR-769-5p可通过上清在细胞间转移,且旁观者细胞的增殖水平明显降低,凋亡率和氧化损伤水平明显升高。使用miR-769-5p inhibitor下调细胞中miR-769-5p的表达,可以观察到急性中长波紫外线旁观者效应的减弱,即接受辐射条件培养基共孵育后,inhibitor预处理组的增殖水平明显高于对照组,凋亡率和氧化损伤水平明显降低。结论 过表达的miR-769-5p能够被旁观者细胞摄取,并介导紫外线旁观者效应。

Objective To investigate the role of miR-769-5p in acute UVA/UVB-radiation induced bystander effect.Methods Human dermal fibroblasts were transfected with miR-769-5p mimics, and 24 h later bystander cells were cultured supernatants obtained.After 48 h of culture,the cell proliferation rate,apoptosis rate and oxidative damage were detected.The expression of miR-769-5p was down-regulated by transfection of miR-769-5p inhibitor.After 24 h,it was incubated with radiation-conditioned medium.After 48 h,the biological indicators as above were detected.Results miR-769-5p mimics up-regulated the expression of miR-769-5p in cells.Overexpression of miR-769-5p could transfer between cells,and the proliferation of bystander cells was significantly decreased.Apoptosis rate and the level of oxidative damage were significantly increased.Using miR-769-5p inhibitor to down-regulate the expression of miR-769-5p in advance could offset the UVA/UVB-radiation induced bystander effects to some extent including increasing proliferation level,reducing apoptotic rate and oxidative damage level.Conclusion Overexpressed miR-769-5p can be uptaken by bystander cells and mediate the UV-radiation induced bystander effects.