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.