TARGETING THE NAV1.2 CHANNEL TO FIND NOVEL ANTICONVULSANT DRUGS: A STRUCTUREBASED DRUG REPOSITIONING APPROACH

LLANOS MANUEL; ENRIQUE, NICOLÁS; MARIA LAURA SBARAGLINI; TALEVI ALAN; MILESI VERONICA; GAVERNET LUCIANA; ALAN TALEVI

Conferencia; Reunion conjunta de sociedades de biociencias; 2023

Epilepsy is the second most common neurological disease globally, affecting nearly 50 million people worldwide. While pharmacotherapy is the first-line treatment for this pathology, current anticonvulsant drugs (ACDs) fail to control seizures in over 30% of patients. In thisregard, our objective was to repurpose existing drugs as safer and better-tolerated ACDs, which overcome the drug resistance problem. To this end, we focused on the voltage-gated sodium channel isoform 1.2 (NaV1.2), a classical target for anticonvulsant drug discovery. Starting from the NaV1.2 Cryo-EM structure, we used Rosetta to sample a conformational ensemble around the initial conformation. Then, a dataset of compounds evaluated against thetarget (323) was docked on every structure of the ensemble (101),systematically exploring several docking conditions. The final model, able to identify compounds binding to the channel’s pore domain, was applied in a virtual screening campaign over the DrugBank database. Three hits: Montelukast (MTK), Cinnarizine (CNZ), and Novobiocin (NVB) were selected for experimental testing by the patchclamp technique on NaV1.2 channels heterologously expressed inHEK293 cells. MTK and CNZ were the most potent inhibitors, blocking 95.3±4.2% (n=6) and 98.1±1.5% (n=6) of the sodium current at 10 μM concentration, respectively. Moreover, all compounds were able to stabilize the inactivated state of NaV1.2 channels, left-shifting the h-curve by -25.66±3.21mV (n=6), -3.32±0.86mV (n=5), and -30.75±3.00mV (n=5) for MTK, NVB and CNZ, respectively. Additionally, in vivo experiments showed that the three candidates presented anticonvulsant effects in three animal models of seizures:the Maximal Electroshock Seizure, 6-Hz psychomotor, and Pentylenetetrazol tests. Altogether, the experimental results validate the high predictive power of the docking model developed, and furthersupport the computer-aided drug repositioning approach as a promising strategy to find novel ACDs