Targeting of hematopoietic stem cells to the CNS and differentiation into glia and neurons

最近的研究表明，骨髓来源的细胞迁移到中枢神经系统（CNS）的血脑屏障和分化成小胶质细胞，星形胶质细胞和可能的神经元。这些报告表明，造血干细胞可用于，第一，以取代神经变性后失去的脑细胞，第二，作为一种天然的车辆迁移通过血脑屏障进入中枢神经系统的可能性。本项目将评估基因工程造血干细胞在小鼠体内的迁移和分化。通过流式细胞术从在β-肌动蛋白启动子下表达绿色荧光蛋白（GFP）的小鼠分离的造血干细胞（lin-、c-kit+、sca-1+）将用神经分化因子（例如FGF-2、EGF）引发短时间，并逆转录病毒转导以表达结合CNS衍生趋化因子的趋化因子受体（例如CX 3CR 1）。然后将GFP标记的细胞静脉注射到小鼠体内，然后通过免疫组织化学，流式细胞术和电生理学分析脑组织。如果成功，该技术将提供一种将造血干细胞靶向CNS的方法，以及它们在包括神经胶质细胞和神经元在内的常驻脑细胞中的可能分化。

Recent studies demonstrate the migration of bone marrow derived cells into the central nervous system (CNS) past the blood-brain barrier and their differentiation into microglia, astrocytes and possibly neurons. These reports suggest the possibility that hematopoietic stem cells may be used, first, to replace brain cells lost following neurodegeneration and, second, as a natural vehicle to migrate through the blood-brain barrier into the CNS. This project will assess the migration and differentiation of genetically engineered hematopoietic stem cells in mice. Hematopoietic stem cells (lin-, c-kit+, sca-1+), isolated by flow cytometry from mice expressing green fluorescenent protein (GFP) under the ß-actin promotor, will be primed for a short time period with neural differentiation factors (e.g. FGF-2, EGF) and retrovirally transduced to express chemokine receptors (e.g. CX3CR1), which bind CNS-derived chemokines. The GFP-marked cells will then be applied intravenously into mice and later analyzed in the brain tissue by immunohistochemistry, flow cytometry and electrophysiology. If successful, this technique will provide a method for targeting of hematopoietic stem cells to the CNS and their possible differentiation in resident brain cells including glial cells and neurons.