Biochemical Modulation of Nociceptive Circuits

描述（由申请人提供）：神经性疼痛是一种慢性和使人衰弱的疾病，难以用现有的镇痛药治疗。最近的研究揭示了溶血磷脂酸（LPA）受体激活在引起神经病理性疼痛中的关键作用。我们发现，许多小直径，推测伤害性，背根神经节（DRG）和三叉神经元表达一种跨膜定位磷酸酶，去磷酸化LPA。基于这些观察，我们的长期研究目标是证明这种磷酸酶调节LPA受体信号在体外，使用培养的感觉神经元，在体内，使用小鼠神经病理性疼痛模型。为了实现这一点，我们将首先使用免疫组织化学来表征表达这种磷酸酶的感觉神经元，并确定受含磷酸酶传入神经支配的外周组织。接下来，我们将使用钙成像和荧光素酶报告基因测定来检验这种磷酸酶调节细胞系和解离的小鼠DRG神经元中LPA受体信号传导的假设。我们将使用表达绿色荧光蛋白的转基因小鼠来鉴定表达这种磷酸酶的DRG神经元。最后，我们将测试的假设，这种磷酸酶调节野生型和磷酸酶基因敲除小鼠的神经病理性疼痛行为。

DESCRIPTION (provided by applicant): Neuropathic pain is a chronic and debilitating disease that is difficult to treat with existing analgesics. Recent studies reveal a critical role for lysophosphatidic acid (LPA) receptor activation in causing neuropathic pain. We found that many small diameter, presumably nociceptive, dorsal root ganglia (DRG) and trigeminal neurons express a transmembrane-localized phosphatase that dephosphorylates LPA. Based on these observations, our long term research objectives are to demonstrate that this phosphatase modulates LPA receptor signaling in vitro, using cultured sensory neurons, and in vivo, using mouse neuropathic pain models. To accomplish this, we will first use immunohistochemistry to characterize the sensory neurons that express this phosphatase and identify the peripheral tissues that are innervated by phosphatase-containing afferents. Next, we will test the hypothesis that this phosphatase modulates LPA receptor signaling in cell lines and in dissociated mouse DRG neurons using calcium imaging and luciferase reporter gene assays. We will use genetically modified mice expressing Green Fluorescent Protein to identify the DRG neurons that express this phosphatase. Finally, we will test the hypothesis that this phosphatase modulates neuropathic pain behaviors in wild-type and phosphatase knockout mice.