Searching for Genes Responsibile for Neuropathic Pain

描述（由申请人提供）：由周围神经损伤引起的神经性疼痛是影响牙科患者生活质量的各种牙科和口腔面部疾病的重要组成部分。神经性疼痛障碍的分子机制尚不清楚。药理学和生理学研究表明，感觉神经元中功能蛋白或基因表达的改变在神经损伤后异常感觉加工中起着重要作用。因此，表征神经损伤后的这些变化是我们更好地理解神经性疼痛和开发神经性疼痛治疗的特定治疗药物或策略的关键一步。然而，在蛋白质水平上研究基因表达的工具受到其特异性和可用性的限制。由于mRNA是编码蛋白的蓝图，而基因芯片技术可用于在mRNA水平上大规模鉴定基因表达的改变，我们建议使用这种新技术来鉴定神经损伤后感觉神经元中表达改变与神经性疼痛发展相关的基因。利用一种定义明确的大鼠神经性疼痛模型：L5/L6腰脊神经紧密结扎，将利用Gone chip分析来鉴定与假手术大鼠相比，神经损伤大鼠腰背根神经节（DRG，包含感觉神经元）中表达改变的基因。为了区分与神经性疼痛相关的潜在靶基因与仅与神经损伤相关的基因，我们将比较神经损伤的Harlan和Holzman大鼠，不同物种对神经性疼痛的易感或抗性，在DRG中的基因表达模式；神经损伤的哈兰大鼠，有神经性疼痛或完全从神经性疼痛中恢复。将通过RNase保护、Western blot分析和原位杂交对神经损伤大鼠靶基因表达的改变进行初步验证。

DESCRIPTION (provided by applicant): Neuropathic pain resulting from peripheral nerve injury represents an important component of various dental and orofacial disorders affecting the quality of life of dental patients. The molecular mechanisms of neuropathic pain disorders are not well understood. Pharmacological and physiological studies have suggested that altered production offimctional proteins, or expression of genes, in sensory neurons plays an important role in abnormal sensory processing after nerve injury. Thus, characterizing these changes after nerve injury is a critical step toward our better understanding of neuropathic pain and development of specific therapeutic agents or strategies for neuropathic pain treatment. However, tools for studying gene expression at the protein level are limited by their specificity and availability. Since mRNAs are blueprints of encoded proteins and gene chip technology is available for large scale identification of altered gene expression at the mRNA level, we propose to use this new technique to identify genes whose altered expression in sensory neurons following nerve injury correlates with neuropathic pain development. Gone chip analyses will be used to identify genes with altered expression in lumbar dorsal root ganglia (DRG, containing sensory neurons) from nerve-injured rats compared to that in sham-operated rats using a well defined rat neuropathic pain model: tight ligation of L5/L6 lumbar spinal nerves. To distinguish potential target genes linked to neuropathic pain from those linked to nerve injury only, gene expression patterns in DRG will be compared between nerve injured Harlan and Holzman rats, different species either susceptible or resistant to neuropathic pain development, respectively; and between nerve injured Harlan rats either with neuropathic pain or fully recovered from neuropathic pain. Preliminary validations of altered target gene expression in nerve injured rats will be performed with RNase protection, Western blot analyses and in situ hybridization.