Attenuation of nicotine-evoked Ca²⁺ influx by antibody to the nicotinic acetylcholine receptor α3 subunits in human embryonic kidney cells

Shota Kobayashi, Shigeru Yokoyama, Takahiro Maruta, Akiko Muroyama, Hiroaki Yoshikawa, Yasuhide Mitsumoto

Department of Biophysical Genetics, Kanazawa University Graduate School of Medicine, Kanazawa, Japan.
Department of Neurology and Neurobiology of Aging, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan.
Laboratory of Alternative Medicine and Experimental Therapeutics, Department of Clinical Pharmacy, Faculty of Pharmaceutical Sciences, Hokuriku University, Kanazawa, Japan.
Neurological Center, Kanazawa Nishi Hospital, Kanazawa, Japan.

DOI: 10.4236/abb.2013.46A002                

Abstract

Autoantibody against neuronal nicotinic acetylcholine receptor (nAChR) α3 subunit is implicated in severe autonomic dysfunction in the patients with autoimmune autonomic ganglionopathy (AAG). Although this autoantibody has been revealed to impair fast excitatory synaptic transmission in autonomic ganglia, its precise mechanism remains unknown. Here, we show that antibody-induced reduction of cell-surface α3 subunits result in impairment of nicotine-evoked Ca²⁺ influx in stably transfected human embryonic kidney cells. These effects of the antibody were remarkably inhibited by interfering with the endocytic machinery at low-temperature. We conclude that reduction of nAChR in autonomic ganglia can be mediated by the endocytosis of α3 subunits, and resulted in autonomic failure in AAG patients.

Keywords

Nicotinic Acetylcholine Receptor α3 Subunit; Antibody; Endocytosis; Ca²⁺ Influx; Autoimmune Autonomic Ganglionopathy

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	McKeon, A., Lennon, V.A., Lachance, D.H., Fealey, R.D. and Pittock, S.J. (2009) Ganglionic acetylcholine receptor autoantibody: Oncological, neurological, and serological accompaniments. Archives of Neurology, 66, 735-741. doi:10.1001/archneurol.2009.78
[2]	Vernino, S., Low, P.A., Fealey, R.D., Stewart, J.D., Farrugia, G. and Lennon, V.A. (2000) Autoantibodies to ganglionic acetylcholine receptors in autoimmune autonomic neuropathies. The New England Journal of Medicine, 343, 847-855. doi:10.1056/NEJM200009213431204
[3]	Skok, V.I. (2002) Nicotinic acetylcholine receptors in autonomic ganglia. Autonomic Neuroscience, 97, 1-11. doi:10.1016/S1566-0702(01)00386-1
[4]	Albuquerque, E.X., Pereira, E.F., Alkondon, M. and Rogers, S.W. (2009) Mammalian nicotinic acetylcholine receptors: From structure to function. Physiological Reviews, 89, 73-120. doi:10.1152/physrev.00015.2008
[5]	Lennon, V.A., Ermilov, L.G., Szurszewski, J.H. and Vernino, S. (2003) Immunization with neuronal nicotinic acetylcholine receptor induces neurological autoimmune disease. The Journal of Clinical Investigation, 111, 907913. doi:10.1172/JCI200317429
[6]	Vernino, S., Ermilov, L.G., Sha, L., Szurszewski., J.H., Low, P.A. and Lennon, V.A. (2004) Passive transfer of autoimmune autonomic neuropathy to mice. The Journal of Neuroscience, 24, 7037-7042. doi:10.1523/JNEUROSCI.1485-04.2004
[7]	Vernino, S., Lindstrom, J., Hopkins, S., Wang, Z. and Low, P.A. (2008) Characterization of ganglionic acetylcholine receptor autoantibodies. Journal of Neuroimmunology, 197, 63-69. doi:10.1016/j.jneuroim.2008.03.017
[8]	Kobayashi, S., Yokoyama, S., Maruta, T., Negami, M., Muroyama, A., Mitsumoto, Y., Iwasa, K., Yamada, M. and Yoshikawa, H. (2013) Autoantibody-induced internalization of nicotinic acetylcholine receptor α3 subunit exogenously expressed in human embryonic kidney cells. Journal of Neuroimmunology, 257, 102-106. doi:10.1016/j.jneuroim.2012.12.010
[9]	Wang, Z., Low, P.A., Jordan, J., Freeman, R., Gibbons, C.H., Schroeder, C., Sandroni, P. and Vernino, S. (2007) Autoimmune autonomic ganglionopathy: IgG effects on ganglionic acetylcholine receptor current. Neurology, 68, 1917-1921. doi:10.1212/01.wnl.0000263185.30294.61
[10]	Arancibia-Carcamo, I.L., Fairfax, B.P., Moss, S.J. and Kittler, J.T. (2006) Studying the localization, surface stability and endocytosis of neurotransmitter receptors by antibody labeling and biotinylation approaches. The dynamic synapse: Molecular methods in ionotropic receptor biology, Frontiers in Neuroscience. CRC Press, Boca Raton.