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Down-regulation of spinal d-amino acid oxidase expression blocks formalin-induced tonic pain
- Source :
-
Biochemical & Biophysical Research Communications . May2012, Vol. 421 Issue 3, p501-507. 7p. - Publication Year :
- 2012
-
Abstract
- Abstract: 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 7days 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. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 0006291X
- Volume :
- 421
- Issue :
- 3
- Database :
- Academic Search Index
- Journal :
- Biochemical & Biophysical Research Communications
- Publication Type :
- Academic Journal
- Accession number :
- 75165116
- Full Text :
- https://doi.org/10.1016/j.bbrc.2012.04.030