酪氨酸家族激酶在大鼠脊髓背角LTP中的作用及其机制

摘要

AIM: To investigate the role of Src - family kinases ( SFKs ) in long - term potentiation ( LTP ) of C - fiber - evoked potentials in rat spinal dorsal horn and the underlying mechanism.METHODS: The effect of SFKs inhibitors on spinal LTP induced by high - frequency stimulation of sciatic nerve was determined by electrophysiological method.The levels of phosphorylated SFKs ( p - SFKs ) in spinal dorsal horn were measured by Western blotting at different time points after LTP induction.The cell types that expressed p - SFKs following LTP induction were determined by double - labeled immunofluorescence staining.RESULTS: Electrophysiological data revealed that pretreatment with SFKs inhibitors ( PP2 or SU6656 ) enabled high - frequency stimulation to induce long - term depression ( LTD ) rather than LTP in spinal dorsal horn.Western blotting analysis showed that the level of p - SFKs in ipsilateral spinal dorsal horn increased at 15 min after LTP induction.Double - labeled immunofluorescence staining demonstrated that p - SFKs were highly restricted to spinal microglia.CONCLUSION: SFKs in microglia play a critical role in the induction of LTP in spinal dorsal horn.Inhibition of SFKs and the downstream molecules may be helpful for curing neuropathic pain.%目的:探讨酪氨酸家族激酶(SFKs)在大鼠脊髓背角C纤维诱发电位的长时程增强(LTP)中的作用及其机制.方法:用在体电生理方法检测SFKs抑制剂对高频刺激坐骨神经诱导的脊髓背角LTP的影响;用Western blotting方法检测高频刺激诱导脊髓LTP的不同时点大鼠脊髓背角磷酸化SFKs的表达情况;用免疫荧光双染方法检测高频刺激诱导脊髓LTP后大鼠脊髓背角磷酸化SFKs表达的细胞学定位.结果:SFKs的抑制剂(PP2或SU6656)可以完全阻断LTP的诱导,甚至将LTP逆转为长时程抑制(LTD);高频电刺激大鼠坐骨神经诱导脊髓LTP后15 min开始,刺激同侧的脊髓背角中磷酸化SFKs表达明显增加,并且这些高表达的磷酸化SFKs仅仅存在于脊髓小胶质细胞中.结论:在脊髓背角,小胶质细胞中的SFKs 是诱导LTP的必要条件,抑制SFKs及其下游分子可能有助于治疗病理性疼痛.