Prewitt C M, Niesman I R, Kane C J, Houlé J D
Department of Anatomy, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA.
Exp Neurol. 1997 Dec;148(2):433-43. doi: 10.1006/exnr.1997.6694.
A prominent role for phagocytic cells in the regenerative response to CNS or PNS injury has been suggested by numerous studies. In the present work we tested whether increasing the presence of phagocytic cells at a spinal cord injury site could enhance the regeneration of sensory axons from cut dorsal roots. Nitrocellulose membranes treated with TGF-beta or coated with microglial cells were cotransplanted with fetal spinal cord tissue into an injured adult rat spinal cord. Cut dorsal roots were apposed to both sides of the nitrocellulose. Four weeks later, animals were sacrificed and spinal cord tissue sections were processed for immunocytochemical detection of calcitonin gene-related peptide (CGRP-ir) to identify regenerated sensory axons. Adjacent sections were processed with the antibody ED-1 or the lectin GSA-B4 for detection of macrophage/microglial cells in association with the regrowing axons. Qualitative and quantitative data indicate a correlation between the pattern and extent of axonal regeneration and the presence of phagocytic cells along the nitrocellulose implant. Axonal regeneration could be experimentally limited by implanting a nitrocellulose strip treated with macrophage inhibitory factor. These results indicate that increasing the presence of activated macrophage/microglial cells at a spinal cord injury site can provide an environment beneficial to the promotion of regeneration of sensory axons, possibly by the release of cytokines and interaction with other nonneuronal cells in the immediate vicinity.
众多研究表明，吞噬细胞在中枢神经系统（CNS）或周围神经系统（PNS）损伤的再生反应中起重要作用。在本研究中，我们测试了增加脊髓损伤部位吞噬细胞的数量是否能促进切断的背根感觉轴突的再生。将经转化生长因子-β（TGF-β）处理或包被有小胶质细胞的硝酸纤维素膜与胎儿脊髓组织共同移植到成年大鼠损伤的脊髓中。切断的背根置于硝酸纤维素膜的两侧。四周后，处死动物，对脊髓组织切片进行免疫细胞化学检测，以检测降钙素基因相关肽（CGRP-ir），从而识别再生的感觉轴突。用抗体ED-1或凝集素GSA-B4处理相邻切片，以检测与再生轴突相关的巨噬细胞/小胶质细胞。定性和定量数据表明，轴突再生的模式和程度与硝酸纤维素植入物周围吞噬细胞的存在之间存在相关性。通过植入经巨噬细胞抑制因子处理的硝酸纤维素条，可在实验中限制轴突再生。这些结果表明，增加脊髓损伤部位活化的巨噬细胞/小胶质细胞数量可提供有利于促进感觉轴突再生的环境，这可能是通过细胞因子的释放以及与附近其他非神经元细胞的相互作用实现的。
