Effects of alpha-7 nicotinic acetylcholine receptor positive allosteric modulator on lipopolysaccharide-induced neuroinflammatory pain in mice

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• 作者：Muzaffar Abbas ; Shafiqur Rahman ; ^{shafiqur.rahman@sdstate.edu" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Nicotinic receptor ; Alpha- 7 positive allosteric modulator ; Neuroinflammatory pain ; Microglia ; Hippocampus ; Mice
• 刊名：European Journal of Pharmacology
• 出版年：2016
• 出版时间：15 July 2016
• 年：2016
• 卷：783
• 期：Complete
• 页码：85-91
• 全文大小：797 K

文摘

Evidence indicates that microglial activation contributes to the pathophysiology and maintenance of neuroinflammatory pain involving central nervous system alpha-7 nicotinic acetylcholine receptors. The objective of the present study was to determine the effects of 3a,4,5,9b-Tetrahydro-4-(1-naphthalenyl)-3H-cyclopentan[c]quinoline-8-sulfonamide (TQS), an alpha-7 nicotinic acetylcholine receptor positive allosteric modulator (PAM), on tactile allodynia and thermal hyperalgesia following lipopolysaccharide (LPS)-induced microglial activation in hippocampus, a neuroinflammatory pain model in mice. In addition, we examined the effects of TQS on microglial activation marker, an ionized calcium-binding adapter molecule 1 (Iba-1), in the hippocampus may be associated with neuroinflammatory pain. Pretreatment of TQS (4 mg/kg) significantly reduced LPS (1 mg/kg)-induced tactile allodynia and thermal hyperalgesia. Moreover, pretreatment of methyllycaconitine (3 mg/kg) significantly reversed TQS-induced antiallodynic and antihyperalgesic responses indicating the involvement of alpha-7 nicotinic acetylcholine receptor. Pretreatment of TQS significantly decreased LPS-induced increased in hippocampal Iba-1 expression. Overall, these results suggest that TQS reduces LPS-induced neuroinflammatory pain like symptoms via modulating microglial activation likely in the hippocampus and/or other brain region by targeting alpha-7 nicotinic acetylcholine receptor. Therefore, alpha-7 nicotinic acetylcholine receptor PAM such as TQS could be a potential drug candidate for the treatment of neuroinflammatory pain.