Abstract: To screen the differentially expression genes (DEGs) in peripheral blood lymphocytes and verify the dose-response and temporal response, and to explore the feasibility of DEGs as a radiation biological dosimeter. Human peripheral blood samples from 3 adult volunteers were exposed to X-rays at doses of 0, 0.1, 0.2, 0.5, 1, 2 and 4 Gy. RNA-sequencing and bioinformatics analyses were performed. DEGs were screened out under the conditions of log₂|Fold Change| ≥2,P<0.05. The cluster heat map analysis, Gene Ontology (GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were applied for the identification of DEGs. Among these DEGs, EDA2R, ACER2, CD70, ACTA2, MGAT3, MAMDC4 were verified for the dose response and temporal response to ionizing radiation by qRT-PCR. We identified 37 DEGs at doses of 0, 0.1, 0.2, 0.5, 1, 2 and 4 Gy at 8 h post-irradiation. The GO analysis of DEGs was mainly enriched in cellular process, single-organism process, cell, cell part, binding. KEGG pathway analysis highlighted the significance of cell growth and death. Doses of 0, 0.1, 0.2, 0.5, 1, 2 and 4 Gy led to a dose-dependent increase in the mRNA levels of EDA2R, ACER2, CD70, ACTA2. The mRNA expression of ACTA2 after 2 Gy X-ray irradiation was shown to be elevated in a time-dependent manner, revealed a temporal response to ionizing radiation. A dose-dependent increase in expression of EDA2R, ACER2, CD70, ACTA2,and a time-dependent increase in ACTA2 in human peripheral lymphocyte samples were demonstrated, indicating the potential of these genes to be biomarkers of human radiation exposure.

Key words: ionizing radiation, peripheral blood lymphocyte, differentially expression gene, dose-response relationship