Liu_2020_Acta.Pharm.Sin.B_10_1926

Acetylcholine (ACh) regulates inflammation via alpha7 nicotinic acetylcholine receptor (alpha7 nAChR). Acetylcholinesterase (AChE), an enzyme hydrolyzing ACh, is expressed in immune cells suggesting non-classical function in inflammatory responses. Here, the expression of PRiMA-linked G4 AChE was identified on the surface of macrophages. In lipopolysaccharide-induced inflammatory processes, AChE was upregulated by the binding of NF-kappaB onto the ACHE promotor. Conversely, the overexpression of G4 AChE inhibited ACh-suppressed cytokine release and cell migration, which was in contrast to that of applied AChE inhibitors. AChEmt, a DNA construct without enzymatic activity, was adopted to identify the protein role of AChE in immune system. Overexpression of G4 AChEmt induced cell migration and inhibited ACh-suppressed cell migration. The co-localization of alpha7 nAChR and AChE was found in macrophages, suggesting the potential interaction of alpha7 nAChR and AChE. Besides, immunoprecipitation showed a close association of alpha7 nAChR and AChE protein in cell membrane. Hence, the novel function of AChE in macrophage by interacting with alpha7 nAChR was determined. Together with hydrolysis of ACh, AChE plays a direct role in the regulation of inflammatory response. As such, AChE could serve as a novel target to treat age-related diseases by anti-inflammatory responses.