Drofenine as a Kv2.1 inhibitor alleviated AD-like pathology in mice through A β/Kv2.1/microglial NLRP3/neuronal tau axis / 中国药理学与毒理学杂志

ABSTRACT

OBJECTIVE Alzheimer disease(AD)is a neurodegenerative disease with clinical hallmarks of pro-gressive cognitive impairment.Synergistic effects of Aβ-tau cascade reaction are tightly implicated in AD patholo-gy,and microglial NLRP3 inflammasome activation drives neuronal tauopathy through microglia and neurons cross-talk.However,the underlying mechanism of how Aβ medi-ates NLRP3 inflammasome remains unclear.Shab related potassium channel member 1(Kv2.1)as a voltage gated po-tassium channel widely distributed in the central nervous system and plays an important role in regulating the out-ward potassium flow in neurons and glial cells.In current work,we aimed to explore the underlying mechanism of Kv2.1 in regulating Aβ/NLRP3 inflammasome/tau axis by using a determined Kv2.1 inhibitor drofenine(Dfe).METHODS Cell-based assays including Western blot-ting and immunofluorescence staining against primary microglia or neurons were carried out to expound the role of Kv2.1 channel in NLRP3 inflammasome activa-tion and subsequent neuronal tau hyperphosphorylation.For animal studies,new object recognition,Y-maze and Morris water maze were performed to evaluate the ame-lioration of Kv2.1 inhibition through either Kv2.1 inhibitor Dfe treatment or adeno-associated virus AAV-ePHP-si-Kv2.1injectionon5×FADADmodel mice.Assays of histol-ogy and immunostaining of tissue sections and Western blotting of brain tissues were performed to verify the con-clusion of cellular assays.RESULTS We reported that oligomeric Aβ(o-Aβ)bound to microglial Kv2.1 and pro-moted Kv2.1-dependent potassium leakage to activate NLRP3 inflammasome through JNK/NF-κB pathway sub-sequently resulting in neuronal tauopathy.Treatment of either Kv2.1 inhibitor Dfe or AAV-ePHP-si-Kv2.1 for brain-specific Kv2.1 knockdown deprived o-A β of its capability in inducing microglial NLRP3 inflammasome activation and neuronal tau hyperphosphorylation,while improved the cognitive impairment of 5×FAD AD model mice.CONCLUSION Our results have highly addressed that Kv2.1 channel is required for o-Aβ driving NLRP3 inflammasome activation and neuronal tauopathy in AD model mice and highlighted that Kv2.1 inhibition is a prom-ising therapeutical strategy for AD and Dfe as a Kv2.1 inhibitor shows potential in the treatment of this disease.