小鼠坐骨神经低温等离子消融后的可逆性损伤与自主修复*

Reversible injury and spontaneous repair after sciatic nerve low temperature plasma ablation model in mice

摘要:

目的：低温等离子消融术(low temperature plasma ablation, LTPA)是治疗神经病理性疼痛的常用微创介入手术，通过消融神经纤维来中断疼痛传导通路，本研究旨在通过建立小鼠坐骨神经LTPA模型并观察神经可逆性损伤和自主修复情况，初步探索LTPA的神经损伤作用和相关不良反应的转归机制。 方法：将54只C57BL/6雌性小鼠随机分为3组：LTPA组使用等离子刀头消融坐骨神经、慢性压迫性损伤模型组(CCI)使用肠铬线结扎、假手术组(Sham)仅暴露和分离，每组18只小鼠。在造模前后3d、7d、14d、21d、28d进行行为学测试（Von Fery测试、热板实验和转棒疲劳实验）观察机械痛阈(mechanical withdrawal threshold, MWT)、热痛阈值((hot withdrawal threshold, HWT)、转棒掉落潜伏期(rotarod fall latency, RFL)以评估感觉和运动功能恢复情况，选取L4 ~ 6背根神经节(Dorsal root ganglion, DRG)进行免疫荧光染色，检测ATF3的平均染色强度。 结果： LTPA组在术后3 ~ 21天MWT高于术前且HWT低于术前，在术后21 ~ 28天明显恢复到术前和Sham水平，RFL在术后3 ~ 28天仍未恢复。而CCI的HWT、MWT、RFL在术后3 ~ 28天维持异常状态。LTPA组和CCI组DRG中ATF3平均染色强度在术后3天后迅速上调，CCI组在3 ~ 28天维持高水平，LTPA组在术后21 ~ 28天下调至Sham组水平。 结论：LTPA可以造成小鼠坐骨神经的可逆性损伤，并在短时间内实现自主修复，且不会产生痛觉超敏现象。这为其临床应用和神经损伤相关不良反应的转归现象提供了理论支撑。

Abstract:

Objective: Low temperature plasma ablation (LTPA) is a commonly used minimally invasive interventional procedure for the treatment of neuropathic pain. A sciatic nerve LTPA model in mice was established to evaluate nerve injury and spontaneous repair status to primitively explore the mechanisms of nerve injury and associated adverse events induced by LTPA. Methods: Fifty-four C57BL/6 female mice were randomly divided into three groups: LTPA group used a plasma knife head to ablate the sciatic nerve, chronic compression injury (CCI) model group used chromic gut ligation, and Sham group was exposed and isolated only, with 18 mice in each group. Behavioral tests (Von Fery test, hot plate test, and rotarod fatigue test) were performed at 3d, 7d, 14d, 21d, and 28d before and after modeling to observe mechanical withdrawal threshold (MWT), hot withdrawal threshold (HWT), and rotarod fall latency (RFL) to assess the recovery of sensory and motor function. and the average staining intensity of ATF3 was detected by immunofluorescence staining of the L4-6 dorsal root ganglion (DRG). Results: In the LTPA group, MWT was higher than the preoperative level and HWT was lower than the preoperative level from 3 to 21 days postoperatively. It recovered significantly to the preoperative and sham levels from 21 to 28 days after surgery, while the RFL did not recover from 3 to 28 days. The MWT, HWT, and RFL of the CCI group remained abnormal from 3 to 28 days postoperatively. The average staining intensity of ATF3 in the DRG of the LTPA and CCI groups was rapidly upregulated after 3 days after surgery. The CCI group maintained a high level from 3 to 28 days, and the LTPA group decreased to the level of Sham group from postoperative 21 to 28 days. Conclusion: LTPA induces a sciatic nerve reversible injury in mice, which repair spontaneously over a short period without inducing pain hypersensitivity. The results provide theoretical support for its clinical application and functional recovery from nerve injury related adverse events.