Alpha7 nicotinic ACh receptor mediated neuroprotective action by nicotine and GTS-21: An approach by the hippocampal organotypic slice cultures.
Year: 2011
Type: article
Abstract: Nicotine, main constituent of tabaco, is known as a nicotinic acetylcholine receptor (nAChR) agonist and increases cognitive performance. 3-(2,4-dimethoxybenzylidene)-anabaseine (GTS-21) is derived from the marine worm toxin, anabaseine, and is alpha7-selective nAChR (D7-nAChR) agonist. Both nicotine and GTS-21 were expected as therapeutic agents of Alzheimer’s disease. Several studies showed that nicotine and GTS-21 protected neuron by activating nAChR, especially D7-nAChR. It has been reported that D7-nAChR has been shown to be an essential regulator of inflammation. The purpose of this study is to examine the neuroprotective and anti-inflammatory effects of nicotine and GTS-21 using organotypic hippocampal slice cultures. Kainic acid (KA, 5-50µM) induced concentration- and time-dependent neuronal cell death in the hippocampal organotypic slice cultures. The pretreatment with nicotine and GTS-21 tended to decrease in KA toxicity. In a CA3 area-specific analysis, pretreatment with nicotine resulted in significant inhibition of KA-induced neurotoxicity. The results suggest that nicotine may protect KA-induced neuronal cell death via D7-nAChR. We also examined anti-inflammatory effects of nicotine and GTS-21. Hippocampal slices were pretreated with nicotine or GTS-21, and then treated with lipopolysaccharide (LPS). LPS treatment induced concentration-dependent increases in TNFD and IL-1E gene expressions. LPS-induced TNFD gene expression, but not IL-1E was suppressed by GTS-21 pretreatment. These results suggest that D7-nAChR might be involved in the microglia activation towards a neuroprotective role by suppressing inflammatory cytokine.
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W601855133