Despite the availability of new drugs on the clinics in recent years, drug-resistant epilepsy remains an unresolved challenge for healthcare, and one-third of epilepsy patients remain refractory to anti-seizure medications. Gene therapy in experimental models has emerged as effective treatment targeting specific neuronal populations in the epileptogenic focus. When combined with an external chemical activator using chemogenetics, it also becomes an "on-demand" treatment. Here, we evaluate a targeted and specific chemogenetic therapy, the PSAM/PSEM system, which holds promise as a potential candidate for clinical application in treating drug-resistant epilepsy. We show that the inert ligand uPSEM817, which selectively activates the chloride-permeable channel PSAM4-GlyR, effectively reduces the number of depolarization-induced action potentials in vitro. This effect is likely due to the shunting of depolarizing currents, as evidenced by decreased membrane resistance in these cells. In organotypic slices, uPSEM817 decreased the number of bursts and peak amplitude of events of spontaneous epileptiform activity. Although administration of uPSEM817 in vivo did not significantly alter electrographic seizures in a male mouse model of temporal lobe epilepsy, it did demonstrate a strong trend toward reducing the frequency of interictal epileptiform discharges. These findings indicate that PSAM4-GlyR-based chemogenetics holds potential as an anti-seizure strategy, although further refinement is necessary to enhance its efficacy.

• MeSH
• akční potenciály účinky léků   MeSH
• chemogenetika MeSH
• epilepsie temporálního laloku * terapie   genetika   MeSH
• epilepsie * terapie   genetika   MeSH
• genetická terapie * metody   MeSH
• hipokampus * metabolismus   patofyziologie   účinky léků   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Epilepsy is a complex disorder affecting the central nervous system and is characterised by spontaneously recurring seizures (SRSs). Epileptic patients undergo symptomatic pharmacological treatments, however, in 30% of cases, they are ineffective, mostly in patients with temporal lobe epilepsy. Therefore, there is a need for developing novel treatment strategies. Transplantation of cells releasing γ-aminobutyric acid (GABA) could be used to counteract the imbalance between excitation and inhibition within epileptic neuronal networks. We generated GABAergic interneuron precursors from human embryonic stem cells (hESCs) and grafted them in the hippocampi of rats developing chronic SRSs after kainic acid-induced status epilepticus. Using whole-cell patch-clamp recordings, we characterised the maturation of the grafted cells into functional GABAergic interneurons in the host brain, and we confirmed the presence of functional inhibitory synaptic connections from grafted cells onto the host neurons. Moreover, optogenetic stimulation of grafted hESC-derived interneurons reduced the rate of epileptiform discharges in vitro. We also observed decreased SRS frequency and total time spent in SRSs in these animals in vivo as compared to non-grafted controls. These data represent a proof-of-concept that hESC-derived GABAergic neurons can exert a therapeutic effect on epileptic animals presumably through establishing inhibitory synapses with host neurons.

• Klíčová slova
• GABA, cell integration, epilepsy, human embryonic stem cells, interneurons, optogenetics, synaptic integration,
• MeSH
• GABA metabolismus   MeSH
• hipokampus metabolismus   patologie   MeSH
• interneurony cytologie   metabolismus   MeSH
• kmenové buňky cytologie   metabolismus   MeSH
• krysa rodu Rattus MeSH
• kultivované buňky MeSH
• kyselina kainová škodlivé účinky   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• recidiva MeSH
• status epilepticus chemicky indukované   metabolismus   patologie   terapie   MeSH
• transplantace kmenových buněk metody   MeSH
• záchvaty chemicky indukované   metabolismus   patologie   terapie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• GABA MeSH
• kyselina kainová MeSH