超高剂量率放疗和常规放疗对小鼠脾脏辐射损伤的转录组学比较研究

Transcriptome Study on Effects of Ultra-high Dose Rate Radiotherapy and Conventional Radiotherapy on Spleen Injury in Mice

为揭示FLASH-RT的潜在作用机制,本文研究了超高剂量率放疗(FLASH-RT)和常规放疗(CONV-RT)对小鼠脾脏基因表达谱的影响。将11只C57BL/6J雄性小鼠按照随机数字法分为健康对照组(Ctrl组)、常规照射组(CONV-RT组)和超高剂量率照射组(FLASH-RT组)。CONV-RT组和FLASH-RT组采用相应的方式对小鼠进行腹部照射,剂量均为12 Gy,照后将小鼠脱颈处死,收集脾脏组织,提取总RNA。通过转录组测序技术和生物信息学分析方法,探究小鼠受照后脾脏组织基因表达谱的变化。结果显示:FLASH-RT组与CONV-RT组之间共有936个差异表达基因(DEGs),其中上调基因321个、下调基因615个;FLASH-RT组与Ctrl组之间共有1337个差异表达基因,其中上调基因322个、下调基因1015个;CONV-RT组与Ctrl组之间共有1082个差异表达基因,其中上调基因445个、下调基因637个。基因本体论(GO)分析显示,FLASH-RT组与CONV-RT组中的DEGs主要涉及对其他生物的防御反应及与其他生物细胞和双链RNA结合等功能,FLASH-RT组与Ctrl组中的DEGs主要涉及对其他生物的防御反应及与宿主细胞细胞质和双链RNA结合等功能。京都基因与基因组百科数据库(KEGG)分析显示,FLASH-RT组与CONV-RT组之间小鼠脾脏组织的差异基因涉及NOD样受体信号通路及抗原加工提呈等多种通路,FLASH-RT组与Ctrl组之间小鼠脾脏组织的差异基因涉及单纯疱疹感染及NOD样受体信号通路等多种KEGG通路。本研究展示了FLASH-RT和CONV-RT可引起小鼠脾脏组织中基因表达谱的改变,这些DEGs涉及多种放射生物学相关的功能通路,FLASH-RT可以降低辐射引起的脾损伤,其机制可能与免疫应答引起的辐射抵抗有关。

In order to study the effect of FLASH radiotherapy(FLASH-RT)and conventional radiotherapy(CONV-RT)on gene expression profile in mouse spleen,and to provide theoretical basis for revealing the potential mechanisms of FLASH-RT,the mice experiments were carried out in different conditions.A total of 11C57BL/6Jmale mice were divided into healthy control group(Ctrl group),CONV-RT group and FLASHRT group according to random number table method.CONV-RT and FLASH-RT groups were irradiated in the abdomen of mice in the corresponding ways,with the dose of 12Gy for both groups.And then the mice in 3groups were killed by neck removal,spleen tissues were collected,and total RNA was extracted.Transcriptome sequencing(RNA-Seq)and bio-informatics analysis were used to investigate the changes of gene expression profiles in spleen tissue of mice after exposure.936differentially expressed genes(DEGs)are identified in group FLASH-RT vs CONV-RT.Among them,321 genes are up-regulated and 615genes are down-regulated.1337DEGs are identified in group FLASH-RT vs Ctrl.Among them,322genes are up-regulated and 1015genes are down-regulated.1082DEGs are identified in groups of CONV-RT vs Ctrl.Among them,445genes are up-regulated and 637genes are down-regulated.According to gene ontology(GO)analysis,these DEGs from group FLASH-RT vs CONV-RT involved various functions including defense response to other organism,other organisms cell,double-stranded RNA binding and so on.These DEGs from groups of FLASH-RT vs Ctrl involved various functions including defense response to other organisms,host cell cytoplasm,double-stranded RNA binding and so on.These DEGs from groups of FLASH-RT vs CONV-RT involved in several Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways including NOD-like receptor signaling pathway,antigen processing and presentation and so on.These DEGs from groups of FLASH-RT vs Ctrl involved in several KEGG pathways including Herpes simplex infection,NOD-like receptor signaling pathway and so on.Irf7is likely to be activated by FLASH radiation.Gene expression profiles in mouse spleen tissues could be altered by FLASH radiation and CONV-RT radiation,and these DEGs involve multiple radiobiologically relevant functional pathways.FLASH-RT reduces radiation-induced spleen injury,and the mechanisms may be related to tissue immune response-induced radiation resistance.