Ozeki Ayumi, Suzuki Keiji, Suzuki Masatoshi, Ozawa Hiroki, Yamashita Shunichi
Department of Radiation Medical Sciences, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
Neuroreport. 2012 Mar 28;23(5):290-3. doi: 10.1097/WNR.0b013e3283509a79.
Neural stem cells (NSCs) are highly susceptible to DNA double-strand breaks; however, little is known about the effects of radiation in cells surviving radiation. Although the nestin-positive NSCs predominantly became glial fibrillary acidic protein (GFAP)-positive in differentiation-permissive medium, little or no cells were GFAP positive in proliferation-permissive medium. We found that more than half of the cells surviving X-rays became GFAP positive in proliferation-permissive medium. Moreover, localized irradiation stimulated differentiation of cells outside the irradiated area. These results indicate for the first time that ionizing radiation is able to stimulate astrocyte-specific differentiation of surviving NSCs, whose process is mediated both by the direct activation of nuclear factor-κB and by the indirect bystander effect induced by X-irradiation.
神经干细胞（NSCs）对DNA双链断裂高度敏感；然而，关于辐射对辐射后存活细胞的影响却知之甚少。尽管在允许分化的培养基中，巢蛋白阳性的神经干细胞主要变为胶质纤维酸性蛋白（GFAP）阳性，但在允许增殖的培养基中，很少或没有细胞呈GFAP阳性。我们发现，在允许增殖的培养基中，超过一半的经X射线照射后存活的细胞变为GFAP阳性。此外，局部照射刺激了照射区域外细胞的分化。这些结果首次表明，电离辐射能够刺激存活神经干细胞向星形胶质细胞特异性分化，其过程由核因子-κB的直接激活和X射线照射诱导的间接旁观者效应介导。
