RESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
Neurodegenerative diseases, including Alzheimer's and Parkinson's disease, are characterized by increased protein aggregation in the brain, progressive neuronal loss, increased inflammation, and neurogenesis impairment. We analyzed the effects of a new purine derivative drug, PDD005, in attenuating mechanisms involved in the pathogenesis of neurodegenerative diseases, using both in vivo and in vitro models. We show that PDD005 is distributed to the brain and can rescue cognitive deficits associated with aging in mice. Treatment with PDD005 prevents impairment of neurogenesis by increasing sex-determining region Y-box 2, nestin, and also enhances synaptic function through upregulation of synaptophysin and postsynaptic density protein 95. PDD005 treatment also reduced neuro-inflammation by decreasing interleukin-1ß expression, activation of astrocytes, and microglia. We identified prohibitin as a potential target in mediating the therapeutic effects of PDD005 for the treatment of cognitive deficit in aging mice. Additionally, in the current study, glycogen synthase kinase appears to attenuate tau pathology.
Assuntos
Transtornos Cognitivos/prevenção & controle , Hipocampo/efeitos dos fármacos , Terapia de Alvo Molecular , Proteínas do Tecido Nervoso/antagonistas & inibidores , Fármacos Neuroprotetores/farmacologia , Proteínas Repressoras/antagonistas & inibidores , Tauopatias/prevenção & controle , Envelhecimento/psicologia , Animais , Barreira Hematoencefálica , Encéfalo/metabolismo , Células Cultivadas , Transtornos Cognitivos/tratamento farmacológico , Donepezila/farmacologia , Avaliação Pré-Clínica de Medicamentos , Células Endoteliais/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Glicogênio Sintase Quinase 3 beta/biossíntese , Glicogênio Sintase Quinase 3 beta/genética , Interleucina-1beta/biossíntese , Interleucina-1beta/genética , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mitocôndrias/efeitos dos fármacos , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/genética , Neurogênese/efeitos dos fármacos , Neuroglia/efeitos dos fármacos , Plasticidade Neuronal/efeitos dos fármacos , Fármacos Neuroprotetores/farmacocinética , Fosforilação/efeitos dos fármacos , Proibitinas , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteínas Repressoras/biossíntese , Proteínas Repressoras/genética , Tauopatias/tratamento farmacológico , Proteínas tau/metabolismoRESUMO
Proteolytic cleavage of the amyloid-ß protein precursor (AßPP) by secretases leads to extracellular release of amyloid-ß (Aß) peptides. Increased production of Aß42 over Aß40 and aggregation into oligomers and plaques constitute an Alzheimer's disease (AD) hallmark. Identifying products of the 'human chemical exposome' (HCE) able to induce Aß42 production may be a key to understanding some of the initiating causes of AD and to generate non-genetic, chemically-induced AD animal models. A cell model was used to screen HCE libraries for Aß42 inducers. Out of 3500+ compounds, six triazine herbicides were found that induced a ß- and γ-secretases-dependent, 2-10 fold increase in the production of extracellular Aß42 in various cell lines, primary neuronal cells, and neurons differentiated from human-induced pluripotent stem cells (iPSCs). Immunoprecipitation/mass spectrometry analyses show enhanced production of Aß peptides cleaved at positions 42/43, and reduced production of peptides cleaved at positions 38 and lower, a characteristic of AD. Neurons derived from iPSCs obtained from a familial AD (FAD) patient (AßPP K724N) produced more Aß42 versus Aß40 than neurons derived from healthy controls iPSCs (AßPP WT). Triazines enhanced Aß42 production in both control and AD iPSCs-derived neurons. Triazines also shifted the cleavage pattern of alcadeinα, another γ-secretase substrate, suggesting a direct effect of triazines on γ-secretase activity. In conclusion, several widely used triazines enhance the production of toxic, aggregation prone Aß42/Aß43 amyloids, suggesting the possible existence of environmental "Alzheimerogens" which may contribute to the initiation and propagation of the amyloidogenic process in late-onset AD.
Assuntos
Peptídeos beta-Amiloides/biossíntese , Herbicidas/química , Herbicidas/farmacologia , Fragmentos de Peptídeos/biossíntese , Triazinas/química , Triazinas/farmacologia , Adulto , Peptídeos beta-Amiloides/agonistas , Animais , Células CHO , Linhagem Celular Tumoral , Células Cultivadas , Cricetinae , Cricetulus , Feminino , Células HEK293 , Humanos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/metabolismo , Masculino , Camundongos , Pessoa de Meia-Idade , Fragmentos de Peptídeos/agonistas , RatosRESUMO
Limited information is available regarding the cellular mechanisms of oxaliplatin-induced painful neuropathy during exposure of patients to this drug. We therefore determined oxidative stress in cultured cells and evaluated its occurrence in C57BL/6 mice. Using both cultured neuroblastoma (SH-SY5Y) and macrophage (RAW 264.7) cell lines and also brain tissues of oxaliplatin-treated mice, we investigated whether oxaliplatin (OXA) induces oxidative stress and apoptosis. Cultured cells were treated with 2-200 µM OXA for 24 h. The effects of pharmacological inhibitors of oxidative stress or inflammation (N-acetyl cysteine, ibuprofen, acetaminophen) were also tested. Inhibitors were added 30 min before OXA treatment and then in combination with OXA for 24 h. In SH-SY5Y cells, OXA caused a significant dose-dependent decrease in viability, a large increase in ROS and NO production, lipid peroxidation and mitochondrial impairment as assessed by a drop in mitochondrial membrane potential, which are deleterious for the cell. An increase in levels of negatively charged phospholipids such as cardiolipin but also phosphatidylserine and phosphatidylinositol, was also observed. Additionally, OXA caused concentration-dependent P2X7 receptor activation, increased chromatin condensation and caspase-3 activation associated with TNF-α and IL-6 release. The majority of these toxic effects were equally observed in Raw 264.7 which also presented high levels of PGE2. Pretreatment of SH-SY5Y cells with pharmacological inhibitors significantly reduced or blocked all the neurotoxic OXA effects. In OXA-treated mice (28 mg/kg cumulated dose) significant cold hyperalgesia and oxidative stress in the tested brain areas were shown. Our study suggests that targeting P2X7 receptor activation and mitochondrial impairment might be a potential therapeutic strategy against OXA-induced neuropathic pain.