Serum microRNA as noninvasive indicator for space radiation

Abstract Ionizing radiation in space is one of the major barriers to long-term or deep-space exploration for human. Although physical dosimeters and biomarkers have been developed to assess the exposure risk during the space flight, there are some limitations existing in these methods such as lack of individual specificity and time-consuming. Serum microRNAs (miRNAs) are ideal biomarkers because they are stable in responding to changes of environments, conservative in different species and easy for collection and detection. The purpose of this study was to identify a set of serum miRNAs which could serve as convenient and sensitive indicators to evaluate the exposure risk of ionizing radiation in space. Eight-week-old Kunming mice were total-body exposed to different doses of carbon ions and X-rays. Serum samples were collected at 24 h after exposure, and miRNAs associated with immune system and hematopoietic system were detected by miRNA PCR array. The serum miRNA expression profiles showed that the levels of 2 miRNAs (let-7a-5p, miR-200b-5p) in irradiated mice were 2 times higher than that in non-irradiated mice ( P