Kv1.3 Channel Blockade by Dalfampridine Attenuates NLRP3 Inflammasome‐Driven Demyelination via the NEK7/Ripk1/FADD Pathway, Matching the Efficacy of Broad P2X7 Antagonism by Suramin in EAE

Abstract

facilitated by different channels such as Panx1, TWIK2, or Kv1.3, is a danger signal that activates programmed cell death in oligodendrocytes via NLRP3 inflammasome and pyroptosis in multiple sclerosis (MS). ATP triggers P2X7 purinergic receptors, which coordinate TWIK-2 and Panx-1 channels. Given this hierarchical signaling architecture, the present study postulated that strategic Kv1.3 intervention using Dalfampridine (Dal) could mirror comprehensive P2X7 blockade with Suramin (Sur) in the experimental autoimmune encephalomyelitis (EAE) as MS animal model. EAE mice received either Dal (10 µg/mouse/day, oral for 2 weeks) or a single Sur injection (100 mg/kg, intraperitoneal). Both interventions demonstrated comparable efficacy in restoring motor function in open field and rotarod tests, preserving myelin integrity under Luxol fast blue stain, and attenuating neuroinflammatory infiltrates within spinal tissues. Molecular profiling confirmed EAE-associated hyperactivation of the ATP-P2X7R-K⁺ efflux cascade. Sur exerted broad-spectrum inhibition, suppressing ATP accumulation, P2X7R overexpression, and all three channels. Conversely, Dal specifically reduced Kv1.3 expression while leaving ATP levels, P2X7R, TWIK-2, and pannexin-1 unchanged. Remarkably, both compounds achieved equivalent disruption of NEK7/Ripk1/FADD/NLRP3 inflammasome complex and pyroptotic machinery, including pro-caspas1 activation and subsequent gasdermin-D cleavage. These findings suggest that Kv1.3 may serve as a contributory node where downstream channel modulation can deliver neuroprotection equivalent to the upstream pathway intervention. By modulating this potential checkpoint, Kv1.3-targeted therapy may reduce collateral effects associated with pan-purinergic blockade, offering a potential streamlined therapeutic corridor for demyelinating neuroinflammation with enhanced specificity and reduced systemic burden.