Effect of total body 137Cs γ-irradiation on the m 6A modification profile of circRNA in mouse bone marrow cells / 中华放射医学与防护杂志

ABSTRACT

Objective:To investigate the effect of ionizing radiation on the N 6-methyladenine (m 6A) modification profile of circular RNA (circRNA) in mouse bone marrow cells and provide scientific basis for revealing the relationship between RNA epigenetic modification and hematopoietic radiation injury. Methods:A total of twenty four C57BL/6 J mice were randomly divided into two groups the healthy control group ( n=12), and ionizing radiation group ( n=12) irradiated in total body with 4 Gy of 137Cs γ-rays. At 5 min after irradiation, mice were killed and bone marrow cells were collected from the femur. Total RNAs were extracted and the changes in circRNA m6A modification profiles were investigated by RNA immunoprecipitation-high-throughput sequencing (MeRIP-Seq) technology and bioinformatics analysis. The representative alterations of m 6A peaks were validated by MeRIP-PCR assay. Results:325 and 455 m 6A sites were identified on circRNAs in the healthy control group and ionizing radiation group (178 common sites, 147 specific sites in the healthy control group and 277 specific sites in ionizing radiation group), respectively. 1 275 and 1 017 deriving genes of m 6A-circRNAs were identified in the healthy control group and ionizing radiation group (767 common genes, 508 specific genes in the healthy control group and 250 specific genes in ionizing radiation group), respectively. Compared with the control healthy group, 414 (178) m 6A peaks was significantly up- (down-) regulated in the ionizing radiation group( P < 10 -10; fold-change cut-off > 5). Moreover, Gene Ontology (GO) assay revealed that the deriving genes of circRNAs with differentially methylated m 6A sites between two groups involves various functions including chromatin regulation, ciliary transition fiber and poly (A)-specific ribonuclease activity. Kyoto Encyclopedia of Genes and Genomes (KEGG) assay revealed that the deriving genes of circRNAs with differentially methylated m 6A sites between two groups included numerous pathways such as platelet activation, Fc γ R-mediated phagocytosis and B cell receptor signaling pathway. Conclusions:Ionizing radiation triggers rapid alterations in the m 6A modification profile of circRNA in mouse bone marrow cells. The deriving genes of differentially methylated circRNAs are associated with a variety of functions and signaling pathways of hematopoietic radiobiology.