Institute of Molecular Medicine, Department of Neurobiology Research, University of Southern Denmark, Odense, Denmark.
J Neuropathol Exp Neurol. 2011 Jun;70(6):481-94. doi: 10.1097/NEN.0b013e31821db3aa.
Current understanding of microglial involvement in disease is influenced by the observation that recruited bone marrow (BM)-derived cells contribute to reactive microgliosis in BM-chimeric mice. In contrast, a similar phenomenon has not been reported for BM-chimeric rats. We investigated the recruitment and microglial transformation of BM-derived cells in radiation BM-chimeric mice and rats after transient global cerebral ischemia, which elicits a characteristic microglial reaction. Both species displayed microglial hyperplasia and rod cell transformation in the hippocampal CA1 region. In mice, a subpopulation of lesion-reactive microglia originated from transformed BM-derived cells. By contrast, no recruitment or microglial transformation of BM-derived cells was observed in BM-chimeric rats. These results suggest that reactive microglia in rats originate from resident microglia, whereas they have a mixed BM-derived and resident origin in mice, depending on the severity of ischemic tissue damage.
目前对于小胶质细胞在疾病中作用的理解受到这样一种观察结果的影响，即募集的骨髓（BM）衍生细胞有助于 BM 嵌合小鼠中的反应性小胶质细胞增生。相比之下，对于 BM 嵌合大鼠，尚未报道类似的现象。我们研究了短暂全脑缺血后 BM 嵌合小鼠和大鼠中 BM 衍生细胞的募集和小胶质细胞转化，这种情况会引发特征性的小胶质细胞反应。两种物种的海马 CA1 区都显示出小胶质细胞增生和杆状细胞转化。在小鼠中，病变反应性小胶质细胞的亚群来源于转化的 BM 衍生细胞。相比之下，在 BM 嵌合大鼠中未观察到 BM 衍生细胞的募集或小胶质细胞转化。这些结果表明，大鼠中的反应性小胶质细胞来源于固有小胶质细胞，而在小鼠中，它们具有 BM 衍生和固有来源的混合体，这取决于缺血性组织损伤的严重程度。
