Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Kanzaki, Norie; Sakoda, Akihiro; Kataoka, Takahiro*; Ishida, Tsuyoshi; Tanaka, Hiroshi; Yamaoka, Kiyonori*
no journal, ,
The aim of this study is to develop a novel radiation risk assessment for the evaluation of radiation-induced "health-loss" by means of Taguchi method that is known as Quality Engineering. In this study, radiation risk was defined as "health-loss", and then we assessed the effects of irradiation in mice with lipopolysaccharide (LPS) induced inflammation using Taguchi's loss function for the formulation of both harmful effects and beneficial effects. LPS 25 and 100 ug were found to be non-lethal dose and lethal dose 46%, respectively. The CRP levels of LPS-treated mice were increased significantly. Next, we assessed the effects of irradiation 4 hours after normal mice were irradiated with X-ray of 0.1, 0.5, or 3.0 Gy. In the case of only irradiation without LPS administration, CRP was not changed. CRP of LPS and X-ray treated mice had a greater tendency to increase than that of LPS treated mice, although the opposite trend was observed in LPS (100 ug) and X-ray (0.1 Gy) treated mice. Finally, we set the conditions of treatments to mouse as the controllable factors and calculated Taguchi's SN-ratio for the smaller the better. Therefore, we found that low-dose irradiation inhibited inflammation because SN-ratio of 0.1 Gy irradiation group was the maximum.
Shimada, Mikio*; Tsukada, Kaima*; Miyake, Tomoko*; Kanzaki, Norie; Yanagihara, Hiromi*; Matsumoto, Yoshihisa*
no journal, ,
Induced pluripotent stem cells (iPSCs) are generated by transduction of reprogramming transcriptional factors. iPSCs have multipotency to differentiate all organs and expected for the application of regenerative medicine. However, it is reported that cancer risk of iPSCs, because of expression of reprogramming factors increased DNA damage. It is important to analysis DNA damage response of iPSCs to prevent chromosomal abnormality and tumor formation. In this study, we attempted to elucidate the molecular mechanism of maintenance of genome stability in iPSCs. RNA-seq analysis by the next generation sequencer showed increased expression of genome maintenance genes such as DNA repair, cell cycle checkpoint and apoptosis. Interestingly, expression level of these genes was decreased after differentiation to the neural stem cells. Furthermore, colony formation assay showed high sensitivity and apoptosis activity to the IR exposure in iPSCs. These results suggested that instead of DNA repair, increasing of apoptosis activity maintain cell population having accurate genome DNA. These molecular insight have important implication for safety medical application of iPSCs.