Therapy for intractable pain by intrathecal administration of antisense oligonucleotides of neurotrophic factor

1.研究大鼠足底切开后脊髓背角c-Fos蛋白(Fos)表达的时空变化规律及局麻药预处理的影响。我们的结果表明，尽管局麻药预处理在术后几天内抑制Fos的表达，但镇痛效果仅在预期的局麻药使用时间内观察到。2.我们检测了脊髓环氧合酶(COX)-2和TrkB受体的mRNAs，以及后爪注射福尔马林后背根节(DRG)中脑源性神经营养因子(BDNF)的表达。我们还检测了脊髓c-FOS mRNA的表达，以阐明中枢通路中神经元活动的变化。C-fos研究表明，SNL诱导的神经病后脊髓神经元对炎症性疼痛的活性降低，可能在急性疼痛知觉的改变中起重要作用。SNL诱导的神经病变后BDNF的mRNA表达增加，提示脊髓中BDNF的过度表达可以减轻福尔马林诱导的疼痛。3.建立了脊髓水平的实时荧光定量PCR方法。因此，我们能够量化非常少量的神经营养因子。此外，我们还获得了原位杂交和鞘内给药的技术。神经营养因子的反义RNA可以在神经病理性疼痛模型中鞘内注射。

1.We investigated the spatial and temporal patterns of c-Fos protein (Fos) expression in the dorsal horn of the spinal cord caused by plantar incision in the rat and the effects of pretreatment with local anesthetics. Our results indicate that although pretreatment with local anesthetics suppresses Fos expression for several days in the postoperative period, the analgesic effect is observed only for the expected duration of the local anesthetic used.2.We measured the mRNAs of cyclooxygenase(COX)-2, and trkB receptor in the spinal cord, and also brain-derived neurotrophic factor(BDNF) in the dorsal root ganglion(DRG) after an injection of formalin in the hind paw of a rat with L5 spinal nerve ligation(SNL)-induced neuropathy. We also measured c-fos mRNA expression in the spinal cord to clarify changes in neuronal activities in the central pathways. c-fos study indicates that the decrease in neuronal activities to inflammation pain in the spinal cord after SNL-induced neuropathy may play an important role in changing in the perception of acute pain. Increase in mRNA of BDNF after SNL-induced neuropathy suggests that overexpression of BDNF in the spinal cord could alleviate formalin-induced pain.3.We established the real-time PCR method to quantify mRNA in the spinal level. Consequently, we became able to quantify a very small amount of neurotrophic factors. Furthermore, we got a technique of in situ hybridization and intrathecal administration of drugs. Antisense RNA of neurotrophic factors can be administered intrathecally in the neuropathic pain model.