氯膦酸盐脂质体通过消耗巨噬细胞延缓周围神经损伤后功能性修复的实验研究

Clodronate liposome alleviates functional regeneration after peripheral nerve injury via depleting macrophages

目的探究巨噬细胞消耗对周围神经损伤修复的影响。方法实验组小鼠腹腔注射氯膦酸盐脂质体消耗巨噬细胞后制备坐骨神经夹伤模型,另外部分小鼠注射空载脂质体后神经损伤作为对照组。术后7 d利用免疫荧光检测F4/80阳性巨噬细胞和GAP43阳性再生轴突。术后28 d再次进行免疫荧光检测F4/80阳性巨噬细胞,并通过行为学、神经电生理检测运动功能和神经传导功能,腓肠肌称重和HE染色评估靶区肌萎缩。结果术后7 d和28 d,实验组神经夹伤远端巨噬细胞消耗效率均达到70%以上,术后7 d神经远端的GAP43阳性再生轴突比对照组更少、更短。术后28 d,实验组小鼠的运动能力和神经传导强度显著下降,神经传导潜伏期延长,腓肠肌湿重比和肌纤维面积显著变小。结论氯膦酸盐脂质体通过巨噬细胞消耗可导致神经损伤后的再生修复能力下降。

Objective To investigate the role of macrophage depletion in functional regeneration after peripheral nerve injury.Methods Adult mice in the experimental group were intraperitoneally injected with the clodronate liposome to exhaust the macrophages and then were subjected a sciatic nerve crush injury model.The mice in the control group were administrated with the control liposome to replace the clodronate.Seven days post injury(dpi),immunofluorescence staining was performed to illustrate the F4/80positive macrophages and the GAP43 positive regenerating axons.At 28 dpi,immunofluorescence staining was used to detect the F4/80 positive macrophages,behavior tests and neuroelectrophysiology were conducted to assay the motor function and nerve conduction.The wet weight of gastrocnemius muscle and their myofiber's size were measured to reflex the myoatrophy in the target muscles.Results The macrophages in the injured nerves were exhausted more than 70% at both 7 dpi and 28 dpi,and GAP43-positive regenerating axons in length at 7dpi were less and shorter in the experimental group than those of the control group.At 28 dpi,compared with the control group,the motor ability and nerve conduction intensity were significantly decreased,the latency of nerve conduction was prolonged,and the wet weight ratio and myofiber size were significantly reduced in the experimental group.Conclusions The clodronate liposome can alleviate the functional regeneration after peripheral nerve injury through exhausting macrophages.