Novel DCPIB analogs as dual inhibitors of VRAC/TREK1 channels reduced cGAS-STING mediated interferon responses

Abstract

The enzyme cyclic GMP-AMP synthase (cGAS) senses cytosolic DNA and catalyzes the formation of 2'3'-cyclic-GMP-AMP (cGAMP), which in turn triggers interferon (IFN) production. Inappropriate activation of cGAS and production of cGAMP have been linked to a diversity of autoimmune diseases. The volume-regulated anion channels (VRACs) have been recently demonstrated to permeate cGAMP, thus making the channel essential for the activation of the cGAS-cGAMP-STING axis. DCPIB, a prominent inhibitor of VRAC channel, has been recently reported to also significantly activate TREK1 channel. Herein, in this study, we have designed and synthesized a series of novel DCPIB derivatives and investigated their potential regulatory effects on VRAC/TREK1 channels. Our results manifested that compound 6u was a dual inhibitor of VRAC/TREK1 channels with IC₅₀s of 7.11 ± 0.94 μM and 4.43 ± 0.90 μM, respectively. On top of that, our data demonstrated that 6u impaired interferon production in a concentration-dependently manner by dampening cGAS-cGAMP-STING pathway without any cytotoxicity when it comes to herpes simplex virus type 1 (HSV1) infection. To sum up, our study not only discovered a novel DCPIB analog with dual inhibitory effects on VRAC/TREK1 channels but also provided a new strategy for the design and development of newly potent VRAC inhibitors, which benefits the treatment of cGAS-STING related autoimmune and inflammatory diseases.

Keywords: DCPIB; Innate immunity; Ion channels; STING; VRAC channel; cGAMP; cGAS.