Nicotine attenuates oxidative stress, activation of redox-regulated transcription factors and induction of proinflammatory genes in compressive spinal cord trauma

• Published in: Brain research. Molecular brain research. 2004-05, Vol.124 (2), p.188-198
• Main Authors: Ravikumar, R., Flora, Govinder, Geddes, James W., Hennig, Bernhard, Toborek, Michal
• Format: Article
• Language: English
• Subjects: Animals; Binding, Competitive - drug effects; Binding, Competitive - genetics; Biological and medical sciences; Chemokine CCL2 - metabolism; Chemokines; CREB; Cyclic AMP Response Element-Binding Protein - metabolism; Cytokines; Disease Models, Animal; Dose-Response Relationship, Drug; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation - drug effects; Gene Expression Regulation - genetics; Inflammation - drug therapy; Inflammation - genetics; Inflammation - metabolism; Inflammation Mediators - metabolism; Male; NF-kappa B - drug effects; NF-kappa B - metabolism; NF-κB, AP-1; Nicotine; Nicotine - pharmacology; Nicotine - therapeutic use; Nicotinic Antagonists - pharmacology; Oxidation-Reduction; Oxidative stress; Oxidative Stress - drug effects; Oxidative Stress - physiology; Rats; Rats, Long-Evans; Receptors, Nicotinic - drug effects; Receptors, Nicotinic - metabolism; RNA, Messenger - drug effects; RNA, Messenger - metabolism; Spinal Cord Compression - drug therapy; Spinal Cord Compression - genetics; Spinal Cord Compression - metabolism; Transcription Factor AP-1 - metabolism; Transcription Factors - drug effects; Transcription Factors - genetics; Treatment Outcome; Tumor Necrosis Factor-alpha - drug effects; Tumor Necrosis Factor-alpha - metabolism; Up-Regulation - drug effects; Up-Regulation - genetics; Vertebrates: nervous system and sense organs
• ISSN: 0169-328X; 1872-6941
• DOI: 10.1016/j.molbrainres.2004.02.018

Pathophysiology of neurodegeneration following spinal cord injury (SCI) involves alterations of cellular redox status, activation of transcription factors and induction of proinflammatory genes. In addition, recent evidence indicates that nicotine can induce potent neuroprotective effects. To study the influence of nicotine on the redox signaling pathways in relationship to SCI, moderate contusions of spinal cords at the level of T-10 were induced in rats treated or untreated with nicotine. Cellular oxidative stress, DNA binding activity of redox-responsive transcription factors (AP-1, NF-κB and CREB) as well as mRNA levels of inflammatory genes (MCP-1 and TNF-α) were determined in the thoracic and lumbar regions of the spinal cords. Nicotine was administrated 2 h after the SCI in a single i.p. injection at the dose of 0.35, 3.5 or 7 mg/kg, and rats were sacrificed 3 h following such an injection. Spinal cord trauma was associated with a significant increase in oxidative stress, and activation of NF-κB, AP-1 and CREB, as well as overexpression of MCP-1 and TNF-α in both the thoracic and lumbar regions. Nicotine administration following the SCI markedly attenuated, especially in the lumbar region, these oxidative and proinflammatory responses. These protective effects of nicotine were fully reversed by inhibition of neuronal nicotinic receptors by mecamylamine. The present results indicate that nicotine administration can attenuate the oxidative injury to spinal cords and suggest that neuronal nicotinic receptors can be attractive targets for neuroprotective therapy.