RESUMEN

Epilepsy is a chronic neurological disorder characterized by episodic dysfunction of central nervous system. The most basic mechanism of epilepsy falls to the imbalance between excitation and inhibition. In adults, GABAA receptor (GABAAR) is the main inhibitory receptor to prevent neurons from developing hyperexcitability, while its inhibition relies on the low intracellular chloride anion concentration ([Cl-]i). Neuronal-specific electroneutral K+-Cl- cotransporter (KCC2) can mediate chloride efflux to lower [Cl-]i for GABAAR mediated inhibition. Our previous study has revealed that the coordinated downregulation of KCC2 and GABAAR participates in epilepsy. According to a high-throughout screen for compounds that reduce [Cl-]i, CLP290 turns out to be a specific KCC2 functional modulator. In current study, we first confirmed that CLP290 could dose-dependently suppress convulsant-induced seizures in mice in vivo as well as the epileptiform burst activities in cultured hippocampal neurons in vitro. Then, we discovered that CLP290 functioned through preventing the downregulation of the KCC2 phosphorylation at Ser940 and hence the KCC2 membrane expression during convulsant stimulation, and consequently restored the GABA inhibition. In addition, while CLP290 was given in early epileptogenesis period, it also effectively decreased the spontaneous recurrent seizures. Generally, our current results demonstrated that CLP290, as a specific KCC2 modulator by enhancing KCC2 function, not only inhibits the occurrence of the ictal seizures, but also suppresses the epileptogenic process. Therefore, we believe KCC2 may be a suitable target for future anti-epileptic drug development.

Asunto(s)

Anticonvulsivantes , Hipocampo , Cotransportadores de K Cl , Neuronas , Convulsiones , Simportadores , Animales , Simportadores/metabolismo , Convulsiones/tratamiento farmacológico , Convulsiones/metabolismo , Ratones , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Masculino , Anticonvulsivantes/farmacología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Receptores de GABA-A/metabolismo , Relación Dosis-Respuesta a Droga , Células Cultivadas , Tiazolidinas

RESUMEN

Most 1,4,5,8-naphthalenediimide (NDI) derivatives, especially those with mild π-acidity cannot achieve photoinduced electron-transfer (PET). Here we report our investigations on the binding interactions of a NDI diammonium dichloride salt (NDI·Cl2) with cucurbit[n]uril (CB[n], n = 8, 10) and the formation process of a NDI radical anion upon photoexcitation of the NDI derivative in the presence of CB[n] (n = 8, 10). As a comparison, the influence of CB[7] on the PET process was also evaluated. The results show that the NDI core can be partially or fully encapsulated in CB[8] or CB[10] to form inclusion complexes at molar ratios of 1 : 1 (CB[8]·NDI2+) or 1 : 2 (CB[10]·2NDI2+). In the presence of the host, quick formation of the NDI radical anion was observed with respect to no radical anion formation without the host. According to the spectral results, interesting CB[8]-promoted charge-transfer interactions between the NDI radical anion and NDI2+ are assumed during UV irradiation. Moreover, from the UV/Vis and EPR spectra, the observation of intense signals of the NDI radical anion in the presence of CB[10], could presumably be related to a much better stabilized NDI radical anion encapsulated in CB[10].