Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
J Pharmacol Sci. 2013;121(2):89-94. doi: 10.1254/jphs.12r14cp. Epub 2013 Jan 22.
Neuropathic pain is a highly debilitating chronic pain state that is a consequence of nerve injury or of diseases such as diabetes, cancer, infection, autoimmune disease, or trauma. Neuropathic pain is often resistant to currently available analgesics. There is a rapidly growing body of evidence indicating that signalings from spinal microglia play crucial roles in the pathogenesis of neuropathic pain. After peripheral nerve injury, microglia transform to reactive states through the expression of various genes such as cell-surface receptors (including purinergic receptors) and proinflammatory cytokines that enhance synaptic transmission in dorsal horn neurons. Inhibiting function or expression of these microglial molecules strongly suppresses pain hypersensitivity to innocuous mechanical stimuli (tactile allodynia), a hallmark symptom of neuropathic pain. A recent study also reveals that the transcription factor IRF8 (interferon regulatory factor 8) is a critical regulator of the nerve injury-induced gene expression in microglia. The present review article highlights the recent advances in our understanding of spinal microglia in neuropathic pain.
神经病理性疼痛是一种高度使人虚弱的慢性疼痛状态，是神经损伤或糖尿病、癌症、感染、自身免疫性疾病或创伤等疾病的后果。神经病理性疼痛通常对目前可用的镇痛药有抵抗力。越来越多的证据表明，脊髓小胶质细胞的信号在神经病理性疼痛的发病机制中起着至关重要的作用。外周神经损伤后，小胶质细胞通过表达各种基因（包括嘌呤能受体）和促炎细胞因子来转化为反应状态，从而增强背角神经元的突触传递。抑制这些小胶质细胞分子的功能或表达可强烈抑制对无害机械刺激（触觉过敏）的疼痛敏感性，这是神经病理性疼痛的一个标志症状。最近的一项研究还揭示了转录因子 IRF8（干扰素调节因子 8）是小胶质细胞中神经损伤诱导基因表达的关键调节剂。本文综述了我们对神经病理性疼痛中小胶质细胞的最新认识进展。
