Potential independent action of sigma receptor ligands through inhibition of the Kv2.1 channel.

Abstract

The sigma-1 receptor (σ1-R) and sigma-2 receptor (σ2-R) are potential drug targets for treatment of cancer, pain, depression, retinal degeneration and other neuronal diseases. Previous reports show that sigma-1 receptor modulates the activities of multiple channels. We are interested in possible sigma receptor modulation of Kv2.1, a K+ channel abundant in retinal photoreceptors. We tested the effect of established sigma receptor ligands on Kv2.1 channels which were stably expressed in HEK293 cells. Surprisingly, σ1-R antagonists inhibited Kv2.1 currents in both wild type and σ1-R knockout HEK293 cells that we engineered using the CRISPR/Cas9 technology. Moreover, PB28, a σ1-R antagonist and also σ2-R agonist, inhibited Kv2.1 in σ1-R knockout cells, but this action was not blocked by the σ2-R antagonists that did not have an effect on Kv2.1. We also observed inhibition of electroretinogram by PB28 in wild type as well as σ1-R knockout mice. Thus, the results in this study indicate that the Kv2.1-inhibiting function of the sigma ligands is not sigma receptor dependent, suggesting a direct effect of these ligands on the Kv2.1 channel.

• Authors: Xinying Liu, Yingmei Fu, Huan Yang, Timur Mavlyutov, Jun Li, Christopher R McCurdy, Lian-Wang Guo, Bikash R Pattnaik
• Journal: Oncotarget (Oncotarget) Vol. 8 Issue 35 Pg. 59345-59358 (Aug 29 2017) ISSN: 1949-2553 [Electronic] United States
• PMID: 28938641 (Publication Type: Journal Article)