Reactive oxygen species contribute to neuropathic pain and locomotor dysfunction via activation of CamKII in remote segments following spinal cord contusion injury in rats
- PMID: 23707296
- DOI: 10.1016/j.pain.2013.05.018
Reactive oxygen species contribute to neuropathic pain and locomotor dysfunction via activation of CamKII in remote segments following spinal cord contusion injury in rats
Abstract
In this study, we examined whether blocking spinal cord injury (SCI)-induced increases in reactive oxygen species (ROS) by a ROS scavenger would attenuate below-level central neuropathic pain and promote recovery of locomotion. Rats with T10 SCI developed mechanical allodynia in both hind paws and overproduction of ROS, as assayed by Dhet intensity, in neurons in the lumbar 4/5 dorsal horn ((∗)P<0.05). To scavenge ROS, phenyl-N-tert-butylnitrone (PBN, a ROS scavenger) was administered immediately after SCI and for 7 consecutive days (early treatment) by either intrathecal (it; 1 and 3mg) or systemic (ip; 10, 50 and 100mg) injections. In addition, the high doses of it (3mg) or ip (100mg) injections were performed at 35 days (delayed treatment) after SCI. High doses of PBN (ip, 100mg, and it, 3mg) significantly attenuated mechanical allodynia in both hind paws at both early and delayed treatments, respectively ((∗)P<0.05). The abnormal hyperexcitability of wide dynamic range neurons after SCI was significantly attenuated by both early and delayed PBN treatment ((∗)P<0.05). Early PBN treatment (100mg, ip, and 3mg, it) attenuated overproduction of ROS in neurons in the lumbar 4/5 dorsal horn. In addition, it and ip t-BOOH (ROS donor) treatment dose-dependently produced mechanical allodynia in both hind paws ((∗)P<0.05). Both SCI and t-BOOH treatment groups showed significantly increased phospho-CamKII (pCamKII) expression in neurons and KN-93 (an inhibitor of pCamKII) significantly attenuated mechanical allodynia ((∗)P<0.05). In addition, high doses of PBN significantly promoted the recovery of locomotion ((∗)P<0.05). In conclusion, the present data suggest that overproduction of ROS contribute to sensory and motor abnormalities in remote segments below the lesion after thoracic SCI.
Keywords: Below-level central neuropathic pain; CamKII; Hyperexcitability; Reactive oxygen species; Spinal cord injury.
Published by Elsevier B.V.
References
-
- Agudo-López A, Miguel BG, Fernández I, Martínez AM. Role of protein kinase C and mitochondrial permeability transition pore in the neuroprotective effect of ceramide in ischemia-induced cell death. FEBS Lett 2011;585:99-103.
-
- Bains M, Hall ED. Antioxidant therapies in traumatic brain and spinal cord injury. Biochim Biophys Acta 2012;1822:675-684.
-
- Bao F, Dekaban GA, Weaver LC. Anti-CD11d antibody treatment reduces free-radical formation and cell death in the injured spinal cord of rats. J Neurochem 2005;94:1361-1373.
-
- Barth BM, Stewart-Smeets S, Kuhn TB. Proinflammatory cytokines provoke oxidative damage to actin in neuronal cells mediated by Rac1 and NADPH oxidase. Mol Cell Neurosci 2009;41:274-285.
-
- Basso DM, Beattie MS, Bresnahan JC. A sensitive and reliable locomotor rating scale for open field testing in rats. J Neurotrauma 1995;12:1-21.
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