Down-regulation of spinal D-amino acid oxidase expression blocks formalin-induced tonic pain
Down-regulation of spinal D-amino acid oxidase expression blocks formalin-induced tonic pain
复制标题
下调脊髓 D-氨基酸氧化酶表达可阻止福尔马林诱导的强直性疼痛
DOI：
10.1016/j.bbrc.2012.04.030
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发表时间：
2012-05-11
影响因子：
3.1
通讯作者：
Wang, Yong-Xiang
中科院分区：
文献类型：
--
作者：
Chen, Xiao-Ling;Li, Xin-Yan;Wang, Yong-Xiang
D-氨基酸氧化酶（DAAO）抑制剂对福尔马林引起的强直性疼痛、神经病理性疼痛和骨癌性疼痛等慢性疼痛具有特异性阻断作用。本研究使用RNA干扰技术进一步验证脊髓DAAO介导福尔马林诱导的疼痛的概念。为了靶向DAAO，设计了在聚醚酰亚胺（PEI）复合物中配制的siRNA/DAAO和在重组腺病毒载体中表达的shRNA/DAAO（shDAAO，在细胞内加工后具有与siRNA/DAAO相同的序列）。与非特异性寡核苷酸相比，siRNA/DAAO可有效阻断NRK-52 E大鼠肾小管上皮细胞中DAAO的表达。此外，每天多次鞘内注射siRNA/DAAO和Ad-shDAAO持续7天，如通过实时定量PCR和Western印迹所测量的，显著抑制脊髓DAAO表达50-80%，并且阻断脊髓DAAO酶活性约60%。同时，siRNA/DAAO和Ad-shDAAO均使福尔马林诱导的强直相疼痛预防约60%。每天多次鞘内注射siRNA/DAAO和Ad-shDAAO也阻断了超过30%的GFAP脊髓表达，GFAP是星形胶质细胞活化的生物标志物。这些结果进一步表明，脊髓DAAO表达和酶活性的下调导致镇痛，其机制可能与脊髓中星形胶质细胞的激活有关。(C)2012 Elsevier Inc. All rights reserved.
A series of inhibitors of D-amino acid oxidase (DAAO) are specific in blocking chronic pain, including formalin-induced tonic pain, neuropathic pain and bone cancer pain. This study used RNA interference technology to further validate the notion that spinal DAAO mediates formalin-induced pain. To target DAAO, a siRNA/DAAO formulated in polyetherimide (PEI) complexation and a shRNA/DAAO (shDAAO, with the same sequence as siRNA/DAAO after intracellular processing) expressed in recombinant adenoviral vectors were designed. The siRNA/DAAO was effective in blocking DAAO expression in NRK-52E rat kidney tubule epithelial cells, compared to the nonspecific oligonucleotides. Furthermore, multiple-daily intrathecal injections of both siRNA/DAAO and Ad-shDAAO for 7 days significantly inhibited spinal DAAO expression by 50-80% as measured by real-time quantitative PCR and Western blot, and blocked spinal DAAO enzymatic activity by approximately 60%. Meanwhile, both siRNA/DAAO and Ad-shDAAO prevented formalin-induced tonic phase pain by approximately 60%. Multiple-daily intrathecal injections of siRNA/DAAO and Ad-shDAAO also blocked more than 30% spinal expression of GFAP, a biomarker for the activation of astrocytes. These results further suggest that down-regulation of spinal DAAO expression and enzymatic activity leads to analgesia with its mechanism potentially related to activation of astrocytes in the spinal cord. (C) 2012 Elsevier Inc. All rights reserved.