The study of Migration of Bone Marrow Derived Microglia (BMDM) to the Cerebellum in Adult Mice induced by Cranial Irradiation.

最近的研究表明，在胚胎第8天之前产生的原始髓系祖细胞衍生的成年小胶质细胞和出生后的造血祖细胞对成年小鼠脑内小胶质细胞的稳态几乎没有贡献。另一方面，一些研究表明，“全身照射”诱导骨髓细胞如小胶质细胞（BMDM）向大脑迁移。从表达增强GFP的转基因小鼠获得供体骨髓细胞（BM）。将表达GFP的BM细胞移植到成年小鼠体内。骨髓移植4周后，一组接受13 Gy的颅脑照射（n = 5），另一组不接受照射（n = 5）。颅脑辐照8周后，获得50mm脑振动体切片。在接受全身和头部照射的组切片中，表达gfp的细胞弥漫性地存在于整个小脑。相比之下，仅接受全身照射的组中仅检测到少量表达gfp的细胞。我们的研究结果表明，在成年小鼠中，颅照射而不是全身照射可诱导外周BMDM向大脑迁移。

Recent studies have shown that adult microglia derived from primitive myeloid progenitors arising prior to embryonic day 8, and postnatal hematopoietic progenitors little contribute to microglia homeostasis in the brain of adult mice. On the other hand, some studies have suggested that “whole body irradiation" induced migration of bone marrow cells like microglia (BMDM) to the brain. Donor bone marrow cells (BM) were obtained from transgenic mice expressing the enhanced GFP. The GFP expressing BM cells were transplanted into adult mice. Four weeks after the BM transplant, one group received cranial irradiation of 13 Gy (n = 5), while another group was observed without irradiation (n = 5). Eight weeks after the cranial irradiation, 50-mm vibratome sections of the brain were obtained. In the sections of the group received whole body and cranial irradiation, GFP-expressing cells were present diffusely throughout the cerebellum. In contrast, only a few GFP-expressing cells were detected in the group received just whole body irradiation. Our results suggest that cranial irradiation, not whole body irradiation, induces migration of peripheral BMDM to the brain in adult mice.