کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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6018529 | 1186520 | 2012 | 12 صفحه PDF | دانلود رایگان |
It is widely accepted that the immune system plays important functional roles in regeneration after injury to the spinal cord. Immune response towards injury involves a complex interplay of immune system cells, such as neutrophils, macrophages and microglia, T- and B-lymphocytes. We investigated the influence of the lymphocyte component of the immune system on the locomotor outcome of severe spinal cord injury in a genetic mouse model of immune suppression. Transgenic mice lacking mature T- and Bâlymphocytes due to the recombination activating gene 2 gene deletion (RAG2â/â mice) were subjected to severe compression of the lower thoracic spinal cord, with the wild-type mice of the same inbred background serving as controls. According to both the Basso Mouse Scale score and single frame motion analysis, the RAG2â/â mice showed improved recovery in comparison to control mice at six weeks after injury. Better locomotor function was associated with enhanced catecholaminergic and cholinergic reinnervation of the spinal cord caudal to injury and increased axonal regrowth/sprouting at the site of injury. Myelination of axons in the ventral column measured as g-ratio was more extensive in RAG2â/â than in control mice 6Â weeks after injury. Additionally, the number of microglia/macrophages was decreased in the lumbar spinal cord of RAG2â/â mice after injury, whereas the number of astrocytes was increased compared with controls. We conclude that T- and B-lymphocytes restrict functional recovery from spinal cord injury by increasing numbers of microglia/macrophages as well as decreasing axonal sprouting and myelination.
⺠RAG2â/â mice show improved motor recovery after lower thoracic spinal cord injury. ⺠Numbers of microglia caudal to injury are lower in RAG2â/â mice than in controls. ⺠Myelination rostral to the lesion site is better in RAG2â/â mice than in controls.
Journal: Experimental Neurology - Volume 237, Issue 2, October 2012, Pages 274-285