PIRT调节TRPV1介导的骨癌痛机理研究

Bone cancer pain, occurs in the late stage of osteosarcoma and bone metastases, seriously affects patients’ living quality. It is suggested that TRPV1, the transient receptor potential vanilloid 1, plays an important role in the generation of bone cancer pain. PIRT, as a membrane protein expressed in the sensory neurons, is essential for the activity of TRPV1. Our prelimilary data showed that in a bone cancer pain mouse model, mechanical pain behavior was reduced in the PIRT knockout mice. We speculate that PIRT participates in the regulation of bone cancer pain via TRPV1. To test our hypothesis, PIRT KO mice and wild-type mice are generated into bone cancer pain mouse model. We want to test the differences of pain behavior, and test the sensitivity of sensory neurons to capsaicin in between wild-type and PIRT KO mice of bone cancer pain by calcium imgaging and electrophysiology. Also, in the bone cancer pain mouse model, we want to test the expression of PIRT, TRPV1, calcitonin gene-related peptide and substance P in cancer tissue as well as the dorsal root ganglia which innervate the bone cancer tissue by immunohistochemistry, Western blot assay, and real-time PCR. The study of PIRT in the bone cancer pain mouse model will provide new ideas for the treatment targets for bone cancer pain in clinical.

骨癌痛好发于晚期骨肉瘤或肿瘤骨转移患者，其产生的剧烈疼痛常难以控制，严重影响患者生活质量。瞬时受体电位离子通道1（TRPV1）在骨癌痛发生中具有重要作用，PIRT为TRPV1介导痛觉传导的重要调节蛋白，共表达于感觉神经元的细胞膜上。我们预实验表明，Pirt基因敲除小鼠（Pirt-/-）的骨癌痛模型中，其机械痛明显下降。据此推测， PIRT通过TRPV1参与骨癌痛的调节。本研究将基于Pirt-/-小鼠与Pirt+/+小鼠的骨癌痛模型，通过行为学实验研究疼痛行为的差异；通过钙成像与膜片钳技术比较感觉神经元对辣椒素（TRPV1激动剂）反应敏感性的差异；通过免疫组织化学、Western blot以及实时荧光定量PCR研究支配肿瘤骨组织的感觉神经元及其神经纤维中PIRT、TRPV1、钙基因相关调节肽与P物质的表达情况。研究PIRT在骨癌痛发生中的调节作用，为骨癌痛的研究和治疗提供新思路。

骨癌痛好发于晚期骨肉瘤或肿瘤骨转移患者，其产生的剧烈疼痛常难以控制，严重影响患者生活质量。瞬时受体电位离子通道1（TRPV1）在骨癌痛发生中具有重要作用，PIRT为TRPV1介导痛觉传导的重要调节蛋白，共表达于感觉神经元的细胞膜上。行为学结果显示Pirt基因敲除骨癌痛模型小鼠热痛、冷痛和机械痛都明显降低；形态学结果显示Pirt和TRPV1共表达于ATF3阳性的DRG神经元上；Western Blot以及实时荧光定量PCR结果显示Pirt基因敲除小鼠（Pirt-/-）TRPV1表达下降，未造模组没有变化；钙成像结果显示骨癌痛模型小鼠DRG神经元对辣椒素（TRPV1激动剂）反应敏感性明显增加，反应细胞和反应大小都明显增加，Pirt敲除组反应敏感性降低，电生理结果显示骨癌痛模型小鼠Pirt基因敲除组辣椒素引起的内向电流明显降低；Pirt基因敲除小鼠使用TRPV1阻断剂，小鼠疼痛行为明显减低，比起单独Pirt敲除和TRPV1阻断疼痛都更为明显。此外我们还发现骨癌痛模型小鼠DRG和坐骨神经P物质表达明显增高，此现象为我们未来的研究提供了新思路。研究PIRT在骨癌痛发生中的调节作用，为骨癌痛的研究和治疗提供新思路。通过上述研究，我们发表SCI论文4篇，其中1篇文章获得南京市优秀科技论文奖。此外还申请了国家专利3项。