Abstract

Purpose

For triage purposes following a nuclear accident or a terrorist event, gene expression biomarkers in blood have been demonstrated to be good bioindicators of ionizing radiation (IR) exposure and can be used to assess the dose received by exposed individuals. Many IR-sensitive genes are regulated by the DNA damage response pathway, and modulators of this pathway could potentially affect their expression level and therefore alter accurate dose estimations. In the present study, we addressed the potential influence of temperature, sample transport conditions and the blood cell fraction analyzed on the transcriptional response of the following radiation-responsive genes: FDXR, CCNG1, MDM2, PHPT1, APOBEC3H, DDB2, SESN1, P21, PUMA, and GADD45.

Materials and Methods

Whole blood from healthy donors was exposed to a 2 Gy X-ray dose with a dose rate of 0.5 Gy/min (output 13 mA, 250 kV peak, 0.2 mA) and incubated for 24 h at either 37, 22, or 4 °C. For mimicking the effect of transport conditions at different temperatures, samples incubated at 37 °C for 24 h were kept at 37, 22 or 4 °C for another 24 h. Comparisons of biomarker responses to IR between white blood cells (WBCs), peripheral blood mononuclear cells (PBMCs) and whole blood were carried out after a 2 Gy X-ray exposure and incubation at 37 °C for 24 hours.

Results

Hypothermic conditions (22 or 4 °C) following irradiation drastically inhibited transcriptional responses to IR exposure. However, sample shipment at different temperatures did not affect gene expression level except for SESN1. The transcriptional response to IR of specific genes depended on the cell fraction used, apart from FDXR, CCNG1, and SESN1.

Conclusion

In conclusion, temperature during the incubation period and cell fraction but not the storing conditions during transport can influence the transcriptional response of specific genes. However, FDXR and CCNG1 showed a consistent response under all the different conditions tested demonstrating their reliability as individual biological dosimetry biomarkers.

中文翻译：

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血液衍生细胞组分、温度和样品运输对基于基因表达的生物剂量测定的作用

摘要

目的

出于核事故或恐怖事件后的分类目的，血液中的基因表达生物标志物已被证明是电离辐射 (IR) 暴露的良好生物指标，可用于评估暴露个体接受的剂量。许多 IR 敏感基因受 DNA 损伤反应通路的调控，该通路的调节剂可能会影响它们的表达水平，从而改变准确的剂量估计。在本研究中，我们讨论了温度、样品运输条件和血细胞分数对以下辐射响应基因转录反应的潜在影响：FDXR、CCNG1、MDM2、PHPT1、APOBEC3H、DDB2、SESN1、P21、 PUMA 和 GADD45。

材料和方法

来自健康供体的全血暴露于 2 Gy X 射线剂量，剂量率为 0.5 Gy/min（输出 13 mA，250 kV 峰值，0.2 mA），并在 37、22 或 4°下孵育 24 小时C。为了模拟不同温度下运输条件的影响，在 37 °C 下孵育 24 小时的样品在 37、22 或 4 °C 下再保持 24 小时。白细胞 (WBC)、外周血单核细胞 (PBMC) 和全血对 IR 的生物标志物反应进行了 2 Gy X 射线照射和 37°C 孵育 24 小时的比较。

结果

辐照后的低温条件（22 或 4 °C）显着抑制了对 IR 暴露的转录反应。然而，不同温度下的样品运输不会影响除 SESN1 之外的基因表达水平。除 FDXR、CCNG1 和 SESN1 外，特定基因对 IR 的转录反应取决于所使用的细胞组分。

结论

总之，潜伏期的温度和细胞分数而不是运输过程中的储存条件会影响特定基因的转录反应。然而，FDXR 和 CCNG1 在所有不同的测试条件下表现出一致的响应，证明它们作为个体生物剂量测定生物标志物的可靠性。