title: The effects of JM-20 on the glutamatergic system in synaptic vesicles, synaptosomes and neural cells cultured from rat brain.
abstract: JM-20 (3-ethoxycarbonyl-2-methyl-4-(2-nitrophenyl)-4,11-dihydro-1H-pyrido[2,3-b][1,5]benzodiazepine) is a novel benzodiazepine dihydropyridine hybrid molecule, which has been shown to be a neuroprotective agent in brain disorders involving glutamate receptors. However, the effect of JM-20 on the functionality of the glutamatergic system has not been investigated. In this study, by using different in vitro preparations, we investigated the effects of JM-20 on (i) rat brain synaptic vesicles (L-[(3)H]-glutamate uptake, proton gradient built-up and bafilomycin-sensitive H(+)-ATPase activity), (ii) rat brain synaptosomes (glutamate release) and (iii) primary cultures of rat cortical neurons, astrocytes and astrocyte-neuron co-cultures (L-[(3)H]-glutamate uptake and glutamate release). We observed here that JM-20 impairs H(+)-ATPase activity and consequently reduces vesicular glutamate uptake. This molecule also inhibits glutamate release from brain synaptosomes and markedly increases glutamate uptake in astrocytes alone, and co-cultured neurons and astrocytes. The impairment of vesicular glutamate uptake by inhibition of the H(+)-ATPase caused by JM-20 could decrease the amount of the transmitter stored in synaptic vesicles, increase the cytosolic levels of glutamate, and will thus down-regulate neurotransmitter release. Together, these results contribute to explain the anti-excitotoxic effect of JM-20 and its strong neuroprotective effect observed in different in vitro and in vivo models of brain ischemia.
authors.affiliation: Centro de Investigación y Desarrollo de Medicamentos, Ave 26, No. 1605 Boyeros y Puentes Grandes, CP 10600, Ciudad Habana, Cuba.
authors.forename: Yanier
authors.initials: Y
authors.lastname: Nuñez-Figueredo
authors.affiliation: Centro de Estudio para las Investigaciones y Evaluaciones Biológicas, Instituto de Farmacia y Alimentos, Universidad de La Habana, ave. 23 # 21425 e/214 y 222, La Coronela, La Lisa, CP 13600, Ciudad Habana, Cuba. Electronic address: gpardo@ifal.uh.cu.
authors.forename: Gilberto L
authors.initials: GL
authors.lastname: Pardo Andreu
authors.affiliation: Departamento de Bioquímica, PPG em Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 anexo, Porto Alegre, RS 90035-003, Brazil.
authors.forename: Samanta
authors.initials: S
authors.lastname: Oliveira Loureiro
authors.affiliation: Departamento de Bioquímica, PPG em Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 anexo, Porto Alegre, RS 90035-003, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Ganzella
authors.affiliation: Centro de Investigación y Desarrollo de Medicamentos, Ave 26, No. 1605 Boyeros y Puentes Grandes, CP 10600, Ciudad Habana, Cuba.
authors.forename: Jeney
authors.initials: J
authors.lastname: Ramírez-Sánchez
authors.affiliation: Laboratorio de Síntesis Orgánica de La Facultad de Química de La Universidad de La Habana (Zapata s/n entre G y Carlitos Aguirre, Vedado Plaza de la Revolución, CP 10400, Ciudad de la Habana, Cuba.
authors.forename: Estael
authors.initials: E
authors.lastname: Ochoa-Rodríguez
authors.affiliation: Laboratorio de Síntesis Orgánica de La Facultad de Química de La Universidad de La Habana (Zapata s/n entre G y Carlitos Aguirre, Vedado Plaza de la Revolución, CP 10400, Ciudad de la Habana, Cuba.
authors.forename: Yamila
authors.initials: Y
authors.lastname: Verdecia-Reyes
authors.affiliation: Centro de Investigación y Desarrollo de Medicamentos, Ave 26, No. 1605 Boyeros y Puentes Grandes, CP 10600, Ciudad Habana, Cuba.
authors.forename: René
authors.initials: R
authors.lastname: Delgado-Hernández
authors.affiliation: Departamento de Bioquímica, PPG em Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 anexo, Porto Alegre, RS 90035-003, Brazil. Electronic address: diogo@ufrgs.br.
authors.forename: Diogo O
authors.initials: DO
authors.lastname: Souza
mesh_terms: D000818:Animals; D001569:Benzodiazepines / Q000494:pharmacology*; D001921:Brain / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002478:Cells, Cultured; D018698:Glutamic Acid / Q000378:metabolism*; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D009525:Niacin / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013572:Synaptic Vesicles / Q000187:drug effects* / Q000378:metabolism; D013574:Synaptosomes / Q000187:drug effects* / Q000378:metabolism
chemical_list: C000591456:3-ethoxycarbonyl-2-methyl-4-(2-nitrophenyl)-4,11-dihydro-1H-pyrido(2,3-b)(1,5)benzodiazepine; D001569:Benzodiazepines; D009525:Niacin; D018698:Glutamic Acid
keywords: Astrocytes; Glutamatergic system; JM-20; Neurons; Synaptic vesicle; Synaptosomes