Biochemical Modulation of Nociceptive Circuits

描述（由申请人提供）：神经性疼痛是一种慢性衰弱性疾病，难以用现有镇痛药治疗。最近的研究揭示了溶血磷脂酸（LPA）受体的激活在引起神经性疼痛中的关键作用。我们发现许多小直径的，可能是伤害性的，背根神经节（DRG）和三叉神经神经元表达一种跨膜定位的磷酸酶，使LPA去磷酸化。基于这些观察，我们的长期研究目标是证明这种磷酸酶在体外通过培养感觉神经元调节LPA受体信号，在体内通过小鼠神经性疼痛模型调节LPA受体信号。为了实现这一目标，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，并识别受含磷酸酶传入神经支配的外周组织。接下来，我们将通过钙成像和荧光素酶报告基因检测来验证这种磷酸酶在细胞系和解离小鼠DRG神经元中调节LPA受体信号的假设。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，我们将验证这种磷酸酶调节野生型和磷酸酶敲除小鼠的神经性疼痛行为的假设。

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.