In a large-scale radiological incident, rapid and high-throughput biodosimetry would be needed. Gene expression-based biodosimetry is a promising approach to determine the dose received after radiation exposure. We previously identified 35 candidate genes as biodosimetry markers based on a systematic review. The goal of the current study was to establish and validate a specific gene expression-based radiological biodosimetry using a panel of highly radioresponsive genes in human peripheral blood for improving the accuracy of dose estimation. Human peripheral blood samples from 30 adult donors were irradiated to 0, 0.5, 1, 2, 3, 4, 6 and 8 Gy with 60 Co γ rays at a dose rate of 1 Gy/min. We examined the expression patterns of candidate genes using real-time polymerase chain reaction (qRT-PCR) at 6, 12, 24 and 48 h postirradiation. Stepwise regression analysis was employed to develop the gene expression-based dosimetry models at each time point. Samples from another 10 healthy donors (blind samples) and four total-body irradiated (TBI) patients were used to validate the radiation dosimetry models. We observed significant linear dose-response relationships of CDKN1A , BAX , MDM2 , XPC , PCNA , FDXR , GDF-15 , DDB2 , TNFRSF10B , PHPT1 , ASTN2 , RPS27L , BBC3 , TNFSF4 , POLH , CCNG1 , PPM1D and GADD45A in human peripheral blood at the various time points. However, the expression levels of these genes were affected by inter-individual variations and gender. We found that the gender-dependent regression models could explain 0.85 of variance at 24 h postirradiation and could also accurately estimate the absorbed radiation doses with dose range of 0–5 Gy, in human peripheral blood samples irradiated ex vivo and from TBI patients, respectively. This study demonstrates that developing gender-specific biodosimetry based on a panel of highly radioresponsive genes may help advance the application of gene expression signature for dose estimation in the event of a radiological accident or in clinical treatment.

Cell death and tissue injury occur as a result of radiation accidents and radiotherapy. The role of endothelial cell damage in mediating radiation-induced acute tissue injury has been extensively studied. We previously demonstrated that ferulic acid (FA) mitigates radiation-induced hematopoietic injury in mice and lessens radiation-induced oxidative damage in human umbilical vein endothelial cells (HUVECs). The purpose of the current study was to determine whether FA can protect HUVECs from radiation toxicity in a cell model via the thrombomodulin (Thbd) pathway, an anti-radiation pathway with anticoagulant, anti-inflammatory and antioxidant properties. HUVEC culture media was supplemented with FA 12 h before 4 Gy 60 Co gamma irradiation. At 30 min postirradiation, the FA media was refreshed, then renewed once daily. HUVEC injury was assessed at day 5 postirradiation through cell proliferation analysis. Ferulic acid significantly ameliorated HUVEC radiation injury, as evidenced by increases in cell viability and angiogenesis and decreases in G 2 /M cell cycle arrest and levels of high mobility group box 1 protein (HMGB1), interleukin (IL)-6 and IL-8. These findings can be attributed to the effect of FA on the Thbd promoter, resulting in increased expression of Thbd and activated protein C with associated radioprotection. These observations indicate that FA intervention significantly ameliorates HUVEC radiation injury via the Thbd pathway. Therefore, FA could be further developed as a potential agent to mitigate radiation-induced damage.