电针干预痛转化效应及其外周蛋白激酶Cε通路调控机制

When the pain transition from acute to chronic, the clinical treatment effect was reducing. Elucidation the mechanism of the transition may lead to new insights into how chronic pain could potentially be reversed. High expression of protein kinase C epsilon (PKCε) in dorsal root ganglion (DRG) was believed playing key role in the transition from acute to choronic pain. Electroacupuncture (EA) was used in treating acute and chronic pain for tens of years. EA could regulate the pain transiton from acute to chronic according to our preliminary work results and these effect probably related with EA’s regulatory effect on PKCε pathway activation in DRG. In this study, the hyperalgesia priming rats model will be produced. The changes of mechanical allodynia and thermal hyperalgesia are observed when the pain transiton from acute to chronic. The activation of PKCε-TRPA1 and PKCε-TRPV1 pathways in DRG are tested. Above all, the relationship between PKCε pathways activation and the changes of mechanical allodynia and thermal hyperalgesia, when transiton from acute to chronic pain, will be demonstration by pharmacology. EA’s regulatory effect on pain transition and PKCε-TRPA1/TRPV1 are investigated by EA administrated at different time point. Finally, the hypothesis that EA regulated transtion from acute to chronic pain via PKCε-TRPA1/TRPV1 in DRG, is demonstrate by using patch clamp and pharmacology. The present project will indicate the effect and periphery mechanism of EA on regulation pain transition from acute to chronic, which will provide scientific insight of new treatment strategy in acupuncture clinical based on treating choronic pain.

痛转化指疼痛由急性向慢性转化的过程。干预痛转化的发生，有助于减少或减轻慢性痛的发生与程度。背根神经节（DRG）中蛋白激酶Cε（PKCε）通路活化已被认为是痛转化产生的关键环节。电针对各类急慢性痛均有良好的治疗效果。前期工作提示电针具有调控痛转化的初步效应，电针极有可能通过调节DRG中PKCε通路的活化发挥该作用。本研究拟建立痛觉敏化诱发大鼠模型，观察痛转化现象和在痛转化中机械痛阈和热痛阈改变规律，DRG中PKCε-TRPA1和PKCε-TRPV1通路活化与痛转化的相关性，并使用药理学手段进行验证。通过不同时间电针介入，观察电针对痛转化的干预效应及其对PKCε-TRPA1/TRPV1通路的调控作用。进一步运用药理学手段和膜片钳技术，验证电针通过DRG中PKCε-TRPA1/TRPV1通路调控痛转化的机制。本研究旨在探索电针干预急性痛向慢性痛转变的效应及其外周机制，为针灸防治慢性痛提供新思路。

痛转化指急性痛向慢性痛转化的过程。预防痛转化的发生，有助于提升慢性痛治疗效果，减轻患者痛苦。DRG水平PKCε通路活化是痛转化产生的关键环节。电针是针灸临床常用的镇痛手段，对各类急/慢性痛均有良好的治疗效果。课题早期实验中发现，电针可能具有调控痛转化的作用，但其机制并不明确。课题组认为，电针可能通过调节DRG水平PKCε通路的活化发挥痛转化调节作用。本研究通过建立痛觉敏化诱发大鼠模型，探索并验证DRG中PKCε-TRPV1通路的活化与痛转化机械痛阈和热痛阈改变之间的关系。通过系统介入不同电针治疗方案，评估电针对痛转化的干预效应及其对PKCε-TRPV1通路的调控作用。在此基础上，运用药理学手段验证DRG中PKCε-TRPV1在痛转化中的作用，以及电针调控痛转化的外周PKCε通路机制。研究结果提示：1.痛转化过程中，外周机械痛和热痛均会明显降低。L4-L6 DRG中PKCε和TRVP1的表达会有明显的提升。2.电针干预能有效反转由于痛转化导致的机械痛和热痛降低。且能一定程度抑制PKCε和TRVP1的高表达。3.激活腰段DRG中PKCε的表达，能诱导出近似痛转化的机械痛和热痛降低，且能提升L4-L6 DRG中的TRPV1表达。抑制腰段DRG中PKCε的表达，不仅能缓解痛转化导致的机械痛和热痛降低，也能抑制TRPV1的表达。4.电针对PKCε激活诱导的痛转化同样具有干预效应，且能抑制由PKCε激活导致的L4-L6 DRG中TRPV1高表达。5.不论是在痛转化前，痛转化后介入电针均对慢性疼痛有一定的干预作用。6.mGluR5和EP1作为PKCε和TRPV1的上游参与痛转化，其在DRG中高表达是痛转化的潜在机制。电针对mGluR5和EP1高表达的干预，是其干预痛转化的机制之一。本研究旨在探索电针干预急性痛向慢性痛转变的作用，初步揭示电针干预痛转化的外周神经机制，为临床针灸镇痛提供新的思路和策略。