Gong_2016_Mol.Med.Rep_14_2257

The functional expression of recombinant alpha7 nicotinic acetylcholine receptors in human embryonic kidney (HEK) 293 cells has presented a challenge. Resistance to inhibitors of cholinesterase 3 (RIC3) has been confirmed to act as a molecular chaperone of nicotinic acetylcholine receptors. The primary objectives of the present study were to investigate whether the coexpression of human (h)RIC3 with human alpha7 nicotinic acetylcholine receptor in HEK 293 cells facilitates functional expression of the alpha7 nicotinic acetylcholine receptor. Subsequent to transfection, western blotting and polymerase chain reaction were used to test the expression of alpha7 nicotinic acetylcholine receptor and RIC-3. The alpha7 nicotinic acetylcholine receptor was expressed alone or coexpressed with hRIC3 in the HEK 293 cells. Drugcontaining solution was then applied to the cells via a gravitydriven perfusion system. Calcium influx in the cells was analyzed using calcium imaging. Nicotine did not induce calcium influx in the HEK 293 cells expressing human alpha7 nicotinic acetylcholine receptor only. However, in the cells coexpressing human RIC3 and alpha7 nicotinic acetylcholine receptor, nicotine induced calcium influx via the alpha7 nicotinic acetylcholine receptor in a concentrationdependent manner (concentration required to elicit 50% of the maximal effect=29.21 microM). Taken together, the results of the present study suggested that the coexpression of RIC3 in HEK 293 cells facilitated the functional expression of the alpha7 nicotinic acetylcholine receptor.