侧脑室注射NGF抗体通过拮抗触液核NGF/ERK信号通路减轻CCI大鼠神经病理性疼痛

ntracerebroventricular injection of NGF antibody alleviate CCI rats neuropathic pain through Inhibition of NGF/ERK pathway of the CSF-CN

摘要:

目的 观察神经生长因子（NGF）在坐骨神经慢性压迫性损伤（CCI）大鼠触液核的表达以及拮抗触液核内NGF对CCI大鼠行为学和触液核ERK表达的影响。方法 首先通过侧脑室注射CB-HRP逆行示踪触液核，结合免疫荧光双标观察正常大鼠是否表达NGF和ERK。 SPF级雄性SD大鼠，体重200-300g，随机分为5组：sham组，CCI 1、3、7、14d组，术前1 d、术后1 d、4 d、7 d、14 d测定mechanical withdrawal threshold (MWT) 和thermal hyperalgesia (TWL)后处死并取触液核并进行Western Blot观察NGF的表达变化情况。第二步实验SD大鼠随机分为六组，CCI+NGF抗体组（NGF antibody组），CCI+PBS组，CCI+对照抗体组（control IgG），sham+NGF抗体组，sham+PBS组，sham+对照抗体组，CCI大鼠第六日在立体定位仪下侧脑室分别注射NGF抗体，PBS及对照抗体，测MWT 和TWL后处死并取触液核并进行Western Blot观察ERK的表达变化情况。结果 正常大鼠触液核表达NGF和ERK。 CCI组大鼠的MWT和TWL明显低于sham组，侧脑室注射NGF抗体后CCI+NGF抗体组大鼠的痛阈 较CCI+PBS组和CCI+对照抗体组明显提高，并且其p-ERK表达较其他两组也明显降低。结论 触液核NGF/ERK信号通路可能参与了大鼠神经病理性疼痛，侧脑室注射NGF抗体可能通过拮抗触液核NGF/ERK信号通路减轻大鼠神经病理性疼痛。

Abstract:

Aim To observe the expression of NGF in cerebrospinal fluid-contacting nucleus (CSF -CN) of neuropathic pain rats,and to study the effect of Intracerebroventricular injection of NGF antibody on CCI rats’ pain behavior and p-ERK in the CSF-CN.Methods We first labeled the distal CSF-CNs using CB-HRP,combinding double-labeled immunofluorescence technique to verify whether normal rats exsist NGF and p-ERK. Male Sprague-Dawley SPF rats, 200-300g were randomly assigned into five groups：sham，CCI 1,3,7,14d. We conducted the test of the mechanical withdrawal threshold (MWT) and thermal hyperalgesia (TWL)on 1d before CCI surgery and 1d, 3d, 7d, and 14d after CCI.We next randomly assigned the rats into six groups: CCI+NGF antibody，CCI+PBS，CCI+control IgG，sham+NGF antibody，sham+PBS，sham+ control IgG，CCI rats were immobilized in a stereotaxic apparatus. NGF antibody,PBS or control IgG was injected lateral intraventricularlly in each rat on day 6. After Von Frey Test and Thermal Plantar Test , the CSF-CN portion of rat brain was isolated to observe the expression of p-ERK.Result normal rats exsisted NGF and ERK.MWT and TWL of CCI rats were lower than sham rats, Intracerebroventricular injection of NGF antibody increased the MWT and TWL of CCI rats and decreased the expression of p-ERK in CSF-CN.Conclusion NGF/ERK pathway in the CSF-CN may participate in the neuropathic, Intracerebroventricular injection of NGF antibody may alleviate CCI rats neuropathic pain through Inhibition of NGF/ERK pathway of the CSF-CN.