A Mouse Ear Model for Bystander Studies Induced by Microbeam Irradiation.
A Mouse Ear Model for Bystander Studies Induced by Microbeam Irradiation.
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DOI：
10.1667/rr14057.1
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发表时间：
2015-08
影响因子：
3.4
通讯作者：
Brenner DJ
中科院分区：
文献类型：
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作者：
Buonanno M;Randers-Pehrson G;Smilenov LB;Kleiman NJ;Young E;Ponnayia B;Brenner DJ
辐射诱导的旁观者效应已在体外和细胞及组织培养模型中观察到，然而，很少有报道表明这些效应在体内。据我们所知，这是第一次报道的旁观者效应的研究微束照射诱导的完整的活的哺乳动物。使用3 MeV质子微束（LET 13.1 keV/µm），在皮肤中的范围约为135 µm，使用小鼠耳朵研究辐射诱导的角质形成细胞旁观者效应。使用定制设计的保持器，通过轻轻抽吸使麻醉的C57 BL/6 J小鼠的耳朵变平，并放置在微束端口上，以沿着沿着35 µm宽、6 mm长的路径照射细胞。组织切片中γ-H2 AX焦点形成的免疫组织化学分析显示，与对照组织相比，在小鼠耳朵的两个表皮层之一中质子诱导的γ-H2 AX焦点形成。引人注目的是，比预期更高数量的细胞显示出来自直接照射效应的病灶。虽然质子辐照的线宽约35 µm，但γ-H2 AX阳性细胞跨越的平均宽度超过150 µm。与γ-H2 AX阳性区域相对的表皮层中或相邻的细胞未显示病灶。这些研究结果验证了这种哺乳动物模型作为一个可行的系统，在一个完整的活生物体中研究辐射诱导的旁观者效应。
Radiation-induced bystander effects have been observed in vitro and in cell and tissue culture models, however, there are few reported studies showing these effects in vivo. To our knowledge, this is the first reported study on bystander effects induced by microbeam irradiation in an intact living mammal. The mouse ear was used to investigate radiation-induced bystander effects in keratinocytes, utilizing a 3 MeV proton microbeam (LET 13.1 keV/µm) with a range in skin of about 135 µm. Using a custom-designed holder, the ear of an anesthetized C57BL/6J mouse was flattened by gentle suction and placed over the microbeam port to irradiate cells along a 35 µm wide, 6 mm long path. Immunohistochemical analysis of γ-H2AX foci formation in tissue sections revealed, compared to control tissue, proton-induced γ-H2AX foci formation in one of the two epidermal layers of the mouse ear. Strikingly, a higher number of cells than expected showed foci from direct irradiation effects. Although the proton-irradiated line was ~35 µm wide, the average width spanned by γ-H2AX-positive cells exceeded 150 µm. Cells adjacent to or in the epidermal layer opposite the γ-H2AX-positive region did not exhibit foci. These findings validate this mammalian model as a viable system for investigating radiation-induced bystander effects in an intact living organism.