摘要
目的:周围神经再生过程中巨噬细胞发挥了重要的作用,然而目前对于神经内内源性和外源性巨噬细胞的具体作用了解的却很少,因此本实验研究了小鼠坐骨神经损伤后早期再生过程中内源性和外源性巨噬细胞数量比例变化的情况,探索周围神经再生的规律。方法:移植CAG-EGFP转基因小鼠的全骨髓有核细胞到骨髓灭活野生型C57Bl/6小鼠体内建立嵌合体小鼠模型。待移植成功3个月后夹伤小鼠一侧坐骨神经,并在损伤后第2、7、14和28天取材、切片,使用巨噬细胞特异性抗体CD68进行免疫荧光染色,分析损伤神经段中内源性巨噬细胞(CD68+/EGFP-)、外源性巨噬细胞(CD68+/EGFP+)的数量及其比例变化情况。结果:①夹伤骨髓移植模型小鼠坐骨神经后,参与坐骨神经损伤修复的巨噬细胞可分为两类,即内源性巨噬细胞(CD68+/EGFP-)和外源性巨噬细胞(CD68+/EGFP+);②夹伤坐骨神经后,浸润的总巨噬细胞数量从第2天开始逐渐增加,到第14天达到高峰,约为正常情况下的60倍,随后逐渐减少;③起初外、内源性巨噬细胞间的比例是1:1,差值最大出现在损伤后第14天为4:1。结论:小鼠坐骨神经夹伤后,内外源性巨噬细胞共同参与了受损神经组织远心段的修复和再生过程,损伤初期发挥作用的主要是内源性巨噬细胞,随后大量浸润的外源性巨噬细胞占主导作用。本实验首次连续观察并定量分析了神经损伤后早期内源性和外源性巨噬细胞的数量改变,证实了瓦勒氏变性过程中内源性和外源性巨噬细胞在不同阶段对巨噬细胞总量的贡献作用。
Objective： Macrophages play an important role in peripheral nerve regeneration, but little is known about the specific functions of endogenous and hematogenous macrophages. In this experiment we investigated the quantitative changes of endogenous and hematogenous macrophages in the early repair and regeneration of sciatic nerve crush injury and explored the rule of peripheral nerve re- generation. Methods： The chimeric mouse model were established by transplanting all the marrow nucleated cells of CAG-EGFP trans- genic mice to the normal wild-type C57B1/6 mice, sciatic nerves of those were transected 3 months after successful transplantation. And then, the damage nerves were collected to examine EGFP＋ cell infiltration situation on the 2rd, 7th, 14th and 28th day after transection. The macrophage marker CD68 for immunofluorescence staining was Used to assess the quantitative changes of endogenous （CD68＋/ EGFP-） and hematogenous （CD68＋/EGFP＋） macrophages which had infiltrated nerve tissues. Results： （1） The macrophage having infil- trated injured sciatic nerves could be divided into two categories which were endogenous macrophages （CD68＋/EGFP-） and hematoge- nous macrophages （CD68＋/EGFP＋）.（2）Throughout all time points examined, macrophages were abundant andpeaked 14 days after sciatic nerves crush injury, with the maximum number reaching 60-fold above baseline. （3） In normal sciatic nerve, the ratio of hematogenous macrophages to endogenous macrophages was 1：1 and it reached the maximum number 4：1 after 14 days. Conclusions： After sciatic nerves crush injury, both endogenous and hematogenous macrophages infiltrate injured nerve tissue and participate in nerve repair and re- generation. Pivotal roles are played by the endogenous macrophages in the early nerve regeneration, and subsequently by the infiltrated hematogenous macrophages. In this research, we characterized the quantitative changes of endogenous and hematogenous macrophages during peripheral nerve reg
出处
《现代生物医学进展》
CAS
2013年第25期4805-4809,共5页
Progress in Modern Biomedicine
基金
国家自然科学基金面上项目(30973050)
关键词
周围神经再生
瓦勒氏变性
巨噬细胞
骨髓移植
Peripheral nerve regeneration
Wallerian degeneration
Macrophages
Bone marrow transplantation
