Preliminary Study On The Changes Of Gene Expressions Of Pig3and Gdf15in Human Blood Lymphocytes As A Biological Dosimeter

Objective:As more and more nuclear activities are involved for human, the possibility of nuclear and radiation accident exposure and nuclear terrorism has been increased. The traditional biological dose estimation method, dicentric and centromeric ring analysis, could not meet the demand of rapid biological dose estimation when a large number of populations exposed to irradiation. It is necessary to find rapid and high-throughput biomarkers for biological dose estimation when a large number of populations exposed to irradiation. Therefore, the present study attempts to use the advanced quantification methods such as real-time PCR and ELISA and so on to analyze the changes of gene expressions of pig3and gdf15in human blood lymphocytes. It will contribute to clarify the ionizing radiation biological effects and its molecular mechanisms. It will provide a new biomarker for radiation damage studies. Also it will accumulate sufficient theoretical evidence for finding more effective, rapid and high-throughput biological dosimeter.Methods.1. The background gene expression levels of pig3and gdf15in peripheral blood lymphocytes of73normal human were analyzed using Taqman MGB method. 2. The peripheral blood samples from three volunteers were cultured4h,12h,24h,48h and72h, respectively after irradiated with0Gy,3Gy,5Gy and8Gy in order to detect the dose-effect and time-effect relationship. The gene expressions of pig3and gdf15in lymphocytes were detected by Taqman MGB and ELISA methods.3. SD rat peripheral blood lymphocytes were irradiated with60Co γ-rays at doses of0Gy,2Gy,4Gy or6Gy in vitro and in vivo. The gene expression changes were analyzed.Results:1. At the mRNA level, the gene expressions of pig3and gdf15in human blood lymphocytes showed no statistically significant difference in different gender groups and different age groups.2. At the mRNA level, the gene expressions of pig3and gdf15in human blood lymphocytes, which were cultured4h-48h after irradiation, showed a good dose-effect relationship in the dose range of0-8Gy and could fitted linear dose-response curves with high R2values. The expression of the two genes has been increased first and then decreased for the lymphocytes which cultured72h after irradiation.3. At the protein level, the PIG3protein level in human blood lymphocytes showed a good dose-effect relationship in certain range of doses that cultured48h and72h after irradiation, which could fitted linear dose-response curves with high R2values. Other time-points could not show a good dose-effect relationship.Conclusions:1. The background gene expression levels of pig3and gdf15in normal human blood lymphocytes are not affected by gender and age. This is the basic aspects of biological dosimeter.2. The mRNA of pig3and gdfl5in normal human blood lymphocytes, which detected with Taqman MGB probe, showed a good dose-effect relationship with0-8Gy irradiation in8-48h time-points. This consolidates that pig3and gdfl5gene expression changes have potential to become a biological dosimeter.3. The PIG3protein levels in normal human blood lymphocytes, which detected with ELISA, showed a good dose-effect relationship with0-5Gy irradiation in48h and72h time-point.