Rhodojaponin VI indirectly targets Cav2.2 channels via N-ethylmaleimide-sensitive fusion protein to alleviate neuropathic pain

Abstract

Neuropathic pain is a chronic disease that severely afflicts the life and emotional status of patients, but currently available treatments are often ineffective. Novel therapeutic targets for the alleviation of neuropathic pain are urgently needed. Rhodojaponin VI, a grayanotoxin from Rhododendron molle, showed remarkable antinociceptive efficacy in models of neuropathic pain, but its biotargets and mechanisms are unknown. Given the reversible action of rhodojaponin VI and the narrow range over which its structure can be modified, we perforwmed thermal proteome profiling of the rat dorsal root ganglion to determine the protein target of rhodojaponin VI. N-Ethylmaleimide-sensitive fusion (NSF) was confirmed as the key target of rhodojaponin VI through biological and biophysical experiments. Functional validation showed for the first time that NSF facilitated trafficking of the Cav2.2 channel to induce an increase in Ca²⁺ current intensity, whereas rhodojaponin VI reversed the effects of NSF. In conclusion, rhodojaponin VI represents a unique class of analgesic natural products targeting Cav2.2 channels via NSF.