Interacting with 7 nAChR is a new mechanism for AChE to enhance the inflammatory response in macrophages.

Acetylcholine (ACh) regulates inflammation 7 nicotinic acetylcholine receptor (7 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-B onto the 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 7 nAChR and AChE was found in macrophages, suggesting the potential interaction of 7 nAChR and AChE. Besides, immunoprecipitation showed a close association of 7 nAChR and AChE protein in cell membrane. Hence, the novel function of AChE in macrophage by interacting with 7 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.