Fang Ping, Pan Hong-Chao, Lin Stanley Li, Zhang Wen-Qing, Rauvala Heikki, Schachner Melitta, Shen Yan-Qin
Center for Neuroscience, Shantou University Medical College, 22 Xinling Road, Shantou, 515041, China.
Mol Neurobiol. 2014 Feb;49(1):472-83. doi: 10.1007/s12035-013-8533-4. Epub 2013 Aug 31.
High mobility group box 1 (HMGB1, also called amphoterin) facilitates neurite outgrowth in early development, yet can exacerbate pathology and inhibit regeneration by inducing adverse neuroinflammation when released from dying cells, suggesting that HMGB1 plays a critical, yet undefined role in neuroregeneration. We explored whether HMGB1 contributes to recovery after complete spinal cord transection in adult zebrafish. Quantitative PCR and in situ hybridization revealed that HMGB1 mRNA levels decreased between 12 h to 11 days after spinal cord injury (SCI), then returned to basal levels by 21 days. Western blot and immunohistological analyses indicated that the time course of HMGB1 protein expression after SCI parallels that of mRNA. Immunofluorescence staining revealed that HMGB1 translocates from nuclei into the cytoplasm of spinal motoneurons at 4 and 12 h (acute stage) following SCI, then accumulates in the nuclei of motoneurons during the ensuing chronic stage (after 6 days following SCI). Immunohistology of transgenic zebrafish, expressing green fluorescent protein in blood vessels, showed enhanced HMGB1 expression in blood vessels in the vicinity of motoneurons. Application of anti-sense HMGB1 morpholinos inhibited locomotor recovery by 34 % and decreased axonal regeneration by 34 % compared to fish treated with a control morpholino. The present study shows that HMGB1 expression increases in both endothelial cells and motoneurons, suggesting that HMGB1 promotes recovery from SCI not only through enhancing neuroregeneration, but also by increasing angiogenesis. The inflammatory effects of HMGB1 are minimized through the decrease in HMGB1 expression during the acute stage.
高迁移率族蛋白B1（HMGB1，也称为双调蛋白）在早期发育中促进神经突生长，但当从死亡细胞中释放时，可通过诱导不良神经炎症加剧病理变化并抑制再生，这表明HMGB1在神经再生中起关键但尚未明确的作用。我们探讨了HMGB1是否有助于成年斑马鱼脊髓完全横断后的恢复。定量PCR和原位杂交显示，脊髓损伤（SCI）后12小时至11天，HMGB1 mRNA水平下降，然后在21天时恢复到基础水平。蛋白质印迹和免疫组织学分析表明，SCI后HMGB1蛋白表达的时间进程与mRNA平行。免疫荧光染色显示，SCI后4小时和12小时（急性期），HMGB1从脊髓运动神经元的细胞核转移到细胞质中，然后在随后的慢性期（SCI后6天）积聚在运动神经元的细胞核中。在血管中表达绿色荧光蛋白的转基因斑马鱼的免疫组织学显示，运动神经元附近血管中的HMGB1表达增强。与用对照吗啉代处理的鱼相比，应用反义HMGB1吗啉代抑制运动恢复34%，并使轴突再生减少34%。本研究表明，HMGB1在内皮细胞和运动神经元中均增加表达，这表明HMGB1不仅通过增强神经再生，而且通过增加血管生成来促进SCI后的恢复。在急性期，通过HMGB1表达的降低，可将HMGB1的炎症作用降至最低。
