SPINAL-CORD MICROGLIAL CELLS AND DRG SATELLITE CELLS RAPIDLY RESPOND TO TRANSECTION OF THE RAT SCIATIC-NERVE
SPINAL-CORD MICROGLIAL CELLS AND DRG SATELLITE CELLS RAPIDLY RESPOND TO TRANSECTION OF THE RAT SCIATIC-NERVE
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DOI：
10.3233/rnn-1991-245605
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发表时间：
1991-07-01
影响因子：
2.8
通讯作者：
KREUTZBERG, GW
中科院分区：
文献类型：
--
作者：
GEHRMANN, J;MONACO, S;KREUTZBERG, GW
横断大鼠坐骨神经可引起背根神经节（DRG）神经元和腰椎L4-L6脊髓节段腹侧灰质运动神经元的逆行变化。在同侧灰质背侧和同侧股薄核中，损伤的DRG神经元中央突出轴突终末场发生跨神经节改变。免疫细胞化学显示，神经元反应与腰髓和股薄核的小胶质细胞的快速增殖和激活有关。反应性小胶质细胞早在坐骨截骨后24小时检测到。小胶质细胞反应在病变后第7天左右达到高峰，在切除后6周左右消失。除光镜外，免疫电镜还在腹侧灰质中发现了活化的神经元周围小胶质细胞。在DRG中，卫星细胞组成性地表达主要组织相容性复合体（MHC） II类抗原。坐骨截骨导致卫星细胞的增殖，特别是MHC II类分子的表达增加。这种卫星细胞反应在开颅24小时后开始，并逐渐增加，直到病变后约6周。在DRG间质组织中，通过单核细胞/巨噬细胞标记物的表达检测到常驻巨噬细胞，也对坐骨截骨有反应。我们的数据表明(1)坐骨截骨术导致腰脊髓腹侧和背侧灰质以及同侧股薄核的小胶质细胞快速反应；(2)坐骨轴突切开术后激活小胶质细胞的免疫表型与颅神经（如面神经）轴突切开术后观察到的免疫表型相当；(3) DRG卫星细胞组成性表达MHCⅱ类分子；(4)坐骨轴突切开术导致坐骨轴突切除DRG中卫星细胞和间质巨噬细胞的快速激活。
Transection of the rat sciatic nerve induces retrograde changes in the dorsal root ganglia (DRG) neurons and in the motoneurons in the ventral grey matter of the lumbar L4-L6 spinal cord segments. In the ipsilateral dorsal grey matter and in the ipsilateral nucleus gracilis, transganglionic changes occur in the terminal fields of the centrally projecting axons of injured DRG neurons. As revealed by immunocytochemistry, the neuronal reactions were associated with a rapid proliferation and activation of microglial cells in the lumbar spinal cord as well as in the nucleus gracilis. Reactive microglial cells were detected as early as 24 h after sciatic axotomy. The microglial reaction had a maximum around day 7 postlesion and disappeared around 6 weeks after axotomy. In addition to light microscopy, activated, perineuronal microglia were identified by immuno-electron microscopy in the ventral grey matter.In the DRG, satellite cells constitutively expressed major histocompatibility complex (MHC) class II antigens. Sciatic axotomy led to a proliferation of satellite cells and an increased expression of MHC class II molecules in particular. This satellite cell reaction started 24 h after axotomy and continued to increase gradually until about 6 weeks after the lesion. Resident macrophages, detected in the DRG interstitial tissue by their expression of monocyte/macrophage markers, also reacted to sciatic axotomy.Our data suggest that (1) sciatic axotomy leads to a rapid microglial reaction in both the ventral and dorsal grey matter of the lumbar spinal cord and in the ipsilateral nucleus gracilis; (2) the immunophenotype of activated microglia following sciatic axotomy is comparable with that observed after axotomy of cranial nerves, e.g. the facial nerve; (3) satellite cells in DRG constitutively express MHC class II molecules; and (4) sciatic axotomy leads to a rapid activation of satellite cells and interstitial macrophages in the axotomized DRG.