RESUMO
Premature ovarian failure (POF) is a leading cause of women's infertility without effective treatment. Here we show that intravenous injection of Ab4B19, an agonistic antibody for the BDNF receptor TrkB, penetrates into ovarian follicles, activates TrkB signaling, and promotes ovary development. In both natural aging and cyclophosphamide-induced POF models, treatment with Ab4B19 completely reverses the reduction of pre-antral and antral follicles, and normalizes gonadal hormone. Ab4B19 also attenuates gonadotoxicity and inhibits apoptosis in cyclophosphamide-induced POF ovaries. Further, treatment with Ab4B19, but not BDNF, restores the number and quality of oocytes and enhances fertility. In human, BDNF levels are high in granulosa cells and TrkB levels increase in oocytes as they mature. Moreover, BDNF expression is down-regulated in follicles of aged women, and Ab4B19 activates TrkB signaling in human ovary tissue ex vivo. These results identify TrkB as a potential target for POF with differentiated mechanisms, and confirms superiority of TrkB activating antibody over BDNF as therapeutic agents.
Assuntos
Fármacos para a Fertilidade Feminina/farmacologia , Glicoproteínas de Membrana/agonistas , Ovário/efeitos dos fármacos , Insuficiência Ovariana Primária/tratamento farmacológico , Receptor trkB/agonistas , Adulto , Envelhecimento/fisiologia , Animais , Apoptose/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/agonistas , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Linhagem Celular Tumoral , Ciclofosfamida/toxicidade , Modelos Animais de Doenças , Feminino , Fertilidade/efeitos dos fármacos , Fármacos para a Fertilidade Feminina/uso terapêutico , Humanos , Masculino , Glicoproteínas de Membrana/metabolismo , Camundongos , Pessoa de Meia-Idade , Técnicas de Cultura de Órgãos , Ovário/patologia , Ovário/fisiopatologia , Insuficiência Ovariana Primária/induzido quimicamente , Insuficiência Ovariana Primária/patologia , Insuficiência Ovariana Primária/fisiopatologia , Receptor trkB/metabolismo , Adulto JovemRESUMO
A Doença de Alzheimer (DA) é a principal forma de demência e um dos grandes desafios no sistema de saúde do século 21. O Comprometimento Cognitvo Leve (CCL) é um estágio que antecede a DA e que compartilha algumas vias metabólicas em comum. A fisiopatologia da DA é caracterizada pela ampla morte neuronal e pela presença de placas neuríticas e emaranhados neurofibrilares, respectivamente relacionadas ao acúmulo de peptídeo beta amiloide (Aß) em tecidos cerebrais e alterações no citoesqueleto que se originam da hiperfosforilação da proteína tau nos neurônios. Algumas linhas de evidência sustentam a hipótese de que o estresse oxidativo, nitrosativo e a inflamação tenham um papel importante na patogênese tanto do DA como do CCL. O selênio, mineral essencial ao ser humano, encontra-se incorporado ao sítio ativo de 25 selenoproteínas, das quais pelo menos um terço apresenta papel antioxidante, além de potencialmente modularem o sistema inflamatório. Deste modo, o estado nutricional adequado dos indivíduos relativo ao selênio, parece exercer efeito neuroprotetor, reduzindo o risco para o CCL e DA e retardando a progressão destas doenças. A entrega de selênio para o cérebro se dá pela interação da selenoproteína P (SELENOP) com o receptor de apolipoproteína E2 (ApoER2). A apolipoproteína E (ApoE) também interage com o ApoER2 no metabolismo de lipídeos. Assim, pode-se pensar que indivíduos portadores do polimorfismo do gene da apolipoproteína E ε4 (APOE ε4), o principal polimorfismo genético para o aumento no risco de desenvolvimento de DA, possam ter essa entrega de selênio prejudicada para o cérebro uma vez que os receptores ApoER2 dos portadores do polimorfismo de APOE ε4 são sequestrados para compartimentos intracelulares, sendo menos expressos na membrana plasmática e portanto diminuindo a interação com a SELENOP. Este trabalho teve por objetivo avaliar se a distribuição do selênio no plasma e líquor de indivíduos portadores de CCL e DA é afetada pelo alelo APOE ε4, avaliar se o estado nutricional do indivíduo em relação ao selênio afeta marcadores de assinatura biológica para DA (peptídeo beta amilóide, proteína tau e proteína tau fosforilada) e concentrações de citocinas inflamatórias. Para tanto, foram selecionadas amostras de plasma e líquor do banco de material biológico do Instituto de Psiquiatria da FMUSP, sendo 14 indivíduos do grupo CCL, 28 indivíduos do grupo DA e 28 indivíduos controles, de ambos os gêneros, com idade acima de 60 anos e residentes na cidade de São Paulo. Foram avaliados os seguintes marcadores: concentrações de selênio no plasma e líquor, concentrações SELENOP no plasma e líquor, citocinas inflamatórias, fator neurotrófico derivado do cérebro (BDNF) e marcadores de assinatura biológica para DA. Não foi evidenciada diferença entre os três diferentes grupos em relação ao selênio e a SELENOP da mesma forma que não houve influência do genótipo APOE ε4 nas concentrações de selênio e SELENOP, porém houve uma tendência de menores concentrações de selênio plasmático nos carreadores do alelo APOE ε4. Também houve uma tendência a uma menor pontuação nos testes MMSE e CAMCOG em indivíduos com menores concentrações plasmáticas de selênio. Não se evidenciou que o estado nutricional dos indivíduos em relação ao selênio influencie as concentrações de marcadores para assinatura biológica para DA e de citocinas inflamatórias, com exceção da IL-10 que apresentou correlação positiva com SELENOP plasmática. A partir desses resultados, conclui-se que o estado nutricional dos indivíduos relativo ao selênio parece não ter influencia significativa em aspectos do CCL e DA e que sua distribuição não é alterada pelo genótipo APOE ε4
Alzheimer's disease (AD) is the main form of dementia and one of the major challenges in the healthcare system of the 21st century. Mild Cognitive Impairment (MCI) is a stage that precedes AD and shares common metabolic pathways. The pathophysiology of AD is characterized by extensive neuronal death, presence of neuritic plaques and neurofibrillary tangles, respectively related to the accumulation of amyloid beta peptide (Aß) in brain tissues and changes in the cytoskeleton that originate from hyperphosphorylation of the Tau protein in neurons. Some lines of evidence support the hypothesis that oxidative, nitrosative stress and inflammation play an important role in the pathogenesis of both AD and MCI. Selenium, an essential mineral to humans, is incorporated into the active site of 25 selenoproteins, of which at least one third has an antioxidant role, in addition to its potential in modulating the inflammatory system. Therefore, the appropriate nutritional status related to selenium seems to exert a neuroprotective effect, reducing the risk for MCI and AD and decreasing the progression of these diseases. Selenium is delivered to the brain by the interaction of selenoprotein P (SELENOP) with the ApoE2 receptor (ApoER2). Apolipoprotein E (ApoE) also interacts with ApoER2 in lipid metabolism. Thus, it can be speculated that individuals that carry apolipoprotein E ε4 gene (APOE ε4), the main genetic polymorphism that increases the risk of AD, may have impaired selenium delivery to the brain since ApoER2 receptors of the APOE ε4 carriers are sequestered to intracellular compartments, being less expressed in the plasma membrane decreasing its interaction with SELENOP. This study aimed to assess whether the distribution of selenium in the plasma and CSF of subjects with MCI and AD is affected by the APOE ε4 allele, evaluate whether the nutritional status of selenium affects biological signature markers for AD (amyloid beta peptide, tau protein and phosphorylated tau protein) and to asses the concentrations of inflammatory cytokines. For this purpose, plasma and cerebrospinal fluid (CSF) samples were selected from the biological material bank of the Institute of Psychiatry of FMUSP, with 14 subjects from the MCI group, 28 from the DA group and 28 from control subjects, both genders, aged over 60 years and São Paulo residents. The following markers were evaluated: selenium concentrations in plasma and CSF, SELENOP concentrations in plasma and CSF, inflammatory cytokines, brain-derived neurotrophic factor (BDNF) and biological signature for AD. There was no difference between the three different groups in relation to selenium and SELENOP; in addition, there was no influence of the APOE ε4 genotype on selenium and SELENOP concentrations, but there was a tendency towards lower plasma selenium concentrations in the APOE ε4 carriers. There was also a tendency for lower scores on the MMSE and CAMCOG tests in subjects with lower plasma selenium concentrations. It was not shown that selenium nutritional status influences the concentrations of biological signature for AD and inflammatory cytokines, with the exception of IL-10 which showed a positive correlation with plasma SELENOP. From these results, we concluded that selenium nutritional status does not seem to have a significant influence in aspects of MCI and DA and that its distribution is not altered by the APOE genotype ε4
Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Selênio/análise , Estado Nutricional/genética , Doença de Alzheimer/patologia , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/patologia , Pessoas/classificação , Fator Neurotrófico Derivado do Encéfalo/agonistas , Selenoproteína P/efeitos adversos , Apolipoproteína E4/agonistas , Fatores de Crescimento Neural/efeitos adversosRESUMO
Of the seven P2X receptor subtypes, P2X4 receptor (P2X4R) is widely distributed in the central nervous system, including in neurons, astrocytes, and microglia. Accumulating evidence supports roles for P2X4R in the central nervous system, including regulating cell excitability, synaptic transmission, and neuropathic pain. However, little information is available about the distribution and function of P2X4R in the peripheral nervous system. In this study, we find that P2X4R is mainly localized in the lysosomes of Schwann cells in the peripheral nervous system. In cultured Schwann cells, TNF-a not only enhances the synthesis of P2X4R protein but also promotes P2X4R trafficking to the surface of Schwann cells. TNF-a-induced BDNF secretion in Schwann cells is P2X4R dependent. in vivo experiments reveal that expression of P2X4R in Schwann cells of injured nerves is strikingly upregulated following nerve crush injury. Moreover, overexpression of P2X4R in Schwann cells by genetic manipulation promotes motor and sensory functional recovery and accelerates nerve remyelination via BDNF release following nerve injury. Our results suggest that enhancement of P2X4R expression in Schwann cells after nerve injury may be an effective approach to facilitate the regrowth and remyelination of injured nerves.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Traumatismos dos Nervos Periféricos/metabolismo , Receptores Purinérgicos P2X4/biossíntese , Recuperação de Função Fisiológica/fisiologia , Remielinização/fisiologia , Células de Schwann/metabolismo , Animais , Animais Recém-Nascidos , Fator Neurotrófico Derivado do Encéfalo/agonistas , Células Cultivadas , Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Traumatismos dos Nervos Periféricos/patologia , Ratos , Ratos Sprague-Dawley , Receptores Purinérgicos P2X4/genética , Recuperação de Função Fisiológica/efeitos dos fármacos , Remielinização/efeitos dos fármacos , Células de Schwann/efeitos dos fármacos , Células de Schwann/patologia , Fator de Necrose Tumoral alfa/toxicidadeRESUMO
We studied the effects of light and non-specific sound stimulation of domestic chick embryos on their filial preference as well as on the expression of two transcriptional factors c-Fos and Egr-1 and neurotrophin BDNF in the embryo brain. Prenatal light stimulation increased preference of the "natural" object, thus producing a priming effect. In the brain of E19 embryos, c-Fos and Egr-1 were expressed at a high basal level and neither light nor sound stimulation affected the number of cells expressing these factors. BDNF mRNA was also present in a number of brain areas of non-stimulated embryos, but light and sound stimulation enhanced the expression of BDNF mRNA in brain structures associated with filial imprinting. These findings suggest that BDNF is probably involved in the effects of prenatal priming on the development of species-specific behavior.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/genética , Encéfalo/efeitos da radiação , Galinhas/genética , Proteína 1 de Resposta de Crescimento Precoce/genética , Reconhecimento Visual de Modelos/efeitos da radiação , Proteínas Proto-Oncogênicas c-fos/genética , Estimulação Acústica , Animais , Comportamento Animal/efeitos da radiação , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Química Encefálica , Fator Neurotrófico Derivado do Encéfalo/agonistas , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Embrião de Galinha , Galinhas/crescimento & desenvolvimento , Galinhas/metabolismo , Comportamento de Escolha/efeitos da radiação , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Luz , Estimulação Luminosa , Proteínas Proto-Oncogênicas c-fos/metabolismo , Transdução de Sinais , SomRESUMO
Glioma is the most common and aggressive of malignant brain tumours. MicroRNAs (miRNAs/miRs) are involved in tumour development of various human cancers, including glioma. Therefore, miRNAs may have potential tumour diagnostic, prognostic and therapeutic values in human glioma. miR103 is abnormally expressed in various human cancer types. However, the detailed expression pattern, biological functions and underlying molecular mechanism of miR103 in glioma remain unclear. Therefore, the present study aimed to investigate the expression, biological roles and underlying mechanisms of miR103 in glioma. Results of the present study demonstrated that miR103 was significantly downregulated in glioma tissues and cell lines. Functional experiments demonstrated that miR103 overexpression inhibited the proliferation and invasion of glioma cells in vitro. Additionally, brainderived neurotrophic factor (BDNF) was identified as a direct functional target of miR103 in glioma. Furthermore, mRNA and protein expression levels of BDNF were highly upregulated in glioma tissues compared with normal brain tissues. Spearman's correlation analysis indicated a negative association between miR103 and BDNF mRNA expression levels in glioma tissues. Furthermore, rescue experiments demonstrated that BDNF upregulation reversed the suppressive effects of miR103 on glioma cell proliferation and invasion. Therefore, the authors of the present study hypothesized that the interaction between miR103 and BDNF serves a role in glioma progression and, in the future, may serve as a therapeutic target for glioma treatment.
Assuntos
Lesões Encefálicas Traumáticas/genética , Neoplasias Encefálicas/genética , Fator Neurotrófico Derivado do Encéfalo/genética , Regulação Neoplásica da Expressão Gênica , Glioma/genética , MicroRNAs/genética , Adulto , Idoso , Antagomirs/genética , Antagomirs/metabolismo , Sequência de Bases , Sítios de Ligação , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/patologia , Lesões Encefálicas Traumáticas/cirurgia , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/cirurgia , Fator Neurotrófico Derivado do Encéfalo/agonistas , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Linhagem Celular Tumoral , Ensaios de Migração Celular , Movimento Celular , Proliferação de Células , Feminino , Genes Reporter , Glioma/metabolismo , Glioma/patologia , Glioma/cirurgia , Humanos , Luciferases/genética , Luciferases/metabolismo , Masculino , MicroRNAs/agonistas , MicroRNAs/antagonistas & inibidores , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Oligorribonucleotídeos/genética , Oligorribonucleotídeos/metabolismo , Plasmídeos/química , Plasmídeos/metabolismo , Transdução de SinaisRESUMO
The pathogenesis of vascular dementia (VD) is associated with neuronal degeneration, apoptosis or necrosis following ischemic brain injury. Lbutylphthalide (LNBP), has been demonstrated to exhibit potent antiischemic and antiVD effects, however the associated specific mechanism remains to be elucidated. The present study generated a VD rat model, in which the effect of LNBP on neurological function and expression levels of brainderived neurotrophic factor (BDNF) and tyrosine kinase receptor B (TrkB) were observed. A total of 90 male Sprague Dawley rats were randomly divided into sham, model and LNBP groups (n=30). The VD model was generated by ligation of bilateral common carotid artery. A Morris water maze was used to test learning and memory functions. Animals were then sacrificed and cortical and hippocampal tissues were extracted. Hematoxylin and Eosin staining was used to observe brain tissue injury, and reverse transcriptionquantitative polymerase chain reaction was employed to measure BDNF and TrkB mRNA levels. Western blotting was employed to measure BDNF, TrkB and serinethreonine protein kinase (Akt) protein levels. Immunohistochemistry staining was used to detect the NmethylDaspartate receptor (NMDAR) levels. VD rats exhibited elongated escape latency and lower crossing times, with significant neuronal damage. LNBP treatment shortened escape latency, increased crossing times and improved cortical and hippocampal injury. BDNF, TrkB, Akt and NMDAR expressions in the treatment group were significantly increased compared with the model group (P<0.05). LNBP may therefore enhance hippocampal expression of BDNF, TrkB, Akt and NMDAR, decrease ischemic injury of VD rats, and improve learning and memory.
Assuntos
Benzofuranos/farmacologia , Fator Neurotrófico Derivado do Encéfalo/genética , Demência Vascular/tratamento farmacológico , Demência Vascular/genética , Fármacos Neuroprotetores/farmacologia , Receptor trkB/genética , Animais , Fator Neurotrófico Derivado do Encéfalo/agonistas , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Artéria Carótida Primitiva/cirurgia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Córtex Cerebral/fisiopatologia , Demência Vascular/metabolismo , Demência Vascular/fisiopatologia , Modelos Animais de Doenças , Regulação da Expressão Gênica , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Ligadura , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Memória de Curto Prazo/efeitos dos fármacos , Memória de Curto Prazo/fisiologia , Proteínas Proto-Oncogênicas c-akt/agonistas , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor trkB/agonistas , Receptor trkB/metabolismo , Receptores de N-Metil-D-Aspartato/agonistas , Receptores de N-Metil-D-Aspartato/genética , Receptores de N-Metil-D-Aspartato/metabolismo , Transdução de SinaisRESUMO
Kai-xin-san (KXS) is a famous Chinese medicinal formula applied for treating stress-related psychiatric diseases with the symptoms such as depression, forgetfulness and dizziness. In clinic, the composition ratio of KXS is always varied and KXS series formulae are created. Here, we aim to compare the anti-depressive effect of different ratios of KXS and reveal its action mechanism on regulation of neurotrophic factor system. Firstly, daily intra-gastric administration of chemically standardized extracts of KXS series formulae for seven days significantly alleviated the depressive symptoms of chronic unpredictable mild stressed mice displayed by enhanced sucrose consumptions and decreased immobile time of forced swimming coupled with increased locomotor activities. KXS might fulfill this effect by up-regulating the expressions of NGF, BDNF and Trk receptors in hippocampus, which were confirmed by the treatment of corresponding blockers tPA-stop and K252a. The ratio with higher amounts of Ginseng Radix et Rhizoma and Polygalae Radix exerted most profound effect on anti-depression and regulation enzymes in metabolic pathway of neurotrophic factors. These findings suggested that KXS was beneficial for enhancing supplies, up-regulating receptors, and restoring the dysfunction of metabolic pathway of neurotrophic factors, which might account for its anti-depression effect.
Assuntos
Antidepressivos/farmacologia , Depressão/tratamento farmacológico , Medicamentos de Ervas Chinesas/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Estresse Psicológico/tratamento farmacológico , Animais , Antidepressivos/química , Fator Neurotrófico Derivado do Encéfalo/agonistas , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Carbazóis/farmacologia , Depressão/genética , Depressão/metabolismo , Depressão/fisiopatologia , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/química , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Humanos , Alcaloides Indólicos/farmacologia , Locomoção/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos ICR , Fator de Crescimento Neural/agonistas , Fator de Crescimento Neural/genética , Fator de Crescimento Neural/metabolismo , Receptor trkA/agonistas , Receptor trkA/antagonistas & inibidores , Receptor trkA/genética , Receptor trkA/metabolismo , Estresse Psicológico/genética , Estresse Psicológico/metabolismo , Estresse Psicológico/fisiopatologia , NataçãoRESUMO
The protective potential of ethyl pyruvate (EP) on neuron has been investigated previously. This study was intended to investigate the effects of EP on the severity of oxygen-glucose deprivation (OGD)-induced injury in neural-like PC12 cells. PC12 cells were exposed to OGD condition with or without EP treatment. Then, cell viability, apoptosis, and the expressions of neurotrophic factors were detected. Further, Sprague-Dawley rats were intravenously administered with 5mg/kg EP for 14 days post-middle cerebral artery occlusion (MCAO). The effects of EP on the infarct volumes and neurological functions of MCAO rats were then assessed. Result showed that EP alleviated OGD-diminished cells viability, OGD-induced apoptosis, and OGD-reduced expressions of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF) and Nestin in PC-12 cells. EP blocked OGD-activated the Notch1 and nuclear factor Kappa B (NF-κB) signaling pathways in PC12 cells. Besides, in vivo data demonstrated that EP treatment decreased infarct volume and mNSS score, and increased the time spent on the rota-rod apparatus of MCAO rats. To conclude, EP protected neural-like PC12 cells from cerebral ischemia-reperfusion injury by suppressing apoptosis and promoting neural restoration. Notch1 and NF-κB pathway might implicated in the functions of EP on neuron.
Assuntos
Apoptose/efeitos dos fármacos , Isquemia Encefálica/tratamento farmacológico , Encéfalo/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Piruvatos/uso terapêutico , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Comportamento Animal/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Isquemia Encefálica/etiologia , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Fator Neurotrófico Derivado do Encéfalo/agonistas , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Infarto da Artéria Cerebral Média/fisiopatologia , Injeções Intravenosas , Masculino , Fator de Crescimento Neural/agonistas , Fator de Crescimento Neural/genética , Fator de Crescimento Neural/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Nestina/agonistas , Nestina/genética , Nestina/metabolismo , Neurônios/metabolismo , Neurônios/patologia , Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/farmacologia , Piruvatos/administração & dosagem , Piruvatos/farmacologia , Distribuição Aleatória , Ratos Sprague-Dawley , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Organismos Livres de Patógenos EspecíficosRESUMO
Three new natural products, corallocins A-C (1-3), along with two known compounds were isolated from the mushroom Hericium coralloides. Their benzofuranone and isoindolinone structures were elucidated by spectral methods. All corallocins induced nerve growth factor and/or brain-derived neurotrophic factor expression in human 1321N1 astrocytes. Furthermore, corallocin B showed antiproliferative activity against HUVEC and human cancer cell lines MCF-7 and KB-3-1.
Assuntos
Agaricales/química , Benzofuranos/isolamento & purificação , Benzofuranos/farmacologia , Fator Neurotrófico Derivado do Encéfalo/agonistas , Fatores de Crescimento Neural/agonistas , Animais , Astrócitos/efeitos dos fármacos , Benzofuranos/química , Alemanha , Humanos , Estrutura Molecular , Proteínas do Tecido Nervoso , Ressonância Magnética Nuclear Biomolecular , Células PC12 , RatosRESUMO
In vegetarian population, vitamin B12 deficiency coexists with suboptimal levels of omega-3 fatty acids. Studies indicate a need for supplementation/fortification of vitamin B12 and omega-3 fatty acids to reduce the risk of brain disorders. We have described the effects of vitamin B12 and omega-3 fatty acid supplementation on brain development in F1 generation animals. The current study investigates the effects of vitamin B12 and omega-3 fatty acids supplementation on brain function and cognition. Pregnant Wistar rats were assigned the following groups: control, vitamin B12 deficient (BD), vitamin B12 deficient + omega-3 fatty acid (BDO), vitamin B12 supplemented (BS), vitamin B12 supplemented + omega-3 fatty acid (BSO). The same diets were continued for two generations. BDO group showed higher (P < 0.05) levels of BDNF (brain derived neurotrophic factor) and DHA (docosahexaenoic acid) in the cortex and hippocampus as compared with the BD group. The cognitive performance was also normalized in this group. BS showed comparable levels of DHA, BDNF (protein and mRNA), and CREB mRNA (cAMP response element-binding protein) to that of control group while Tropomyosin receptor kinase mRNA levels were higher. The combined vitamin B12 and omega-3 fatty acid supplementation further enhanced the levels of DHA (P < 0.05) and BDNF (P < 0.05) in the hippocampus and CREB mRNA (P < 0.01) in the cortex as compared with BS group. The cognitive performance of these animals was higher (P < 0.05) as compared with BS group. Our data indicates the beneficial effects of vitamin B12 and omega-3 fatty acid supplementation across two generations on brain development and function.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/genética , Cognição/efeitos dos fármacos , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/metabolismo , Ácidos Graxos Ômega-3/administração & dosagem , Vitamina B 12/administração & dosagem , Animais , Fator Neurotrófico Derivado do Encéfalo/agonistas , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proteína de Ligação a CREB/genética , Proteína de Ligação a CREB/metabolismo , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Feminino , Alimentos Formulados , Expressão Gênica , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Receptor trkA/genética , Receptor trkA/metabolismoRESUMO
Recent evidence has shown that Ras homolog enriched in brain (Rheb) is dysregulated in Alzheimer's disease (AD) brains. However, it is still unclear whether Rheb activation contributes to the survival and protection of hippocampal neurons in the adult brain. To assess the effects of active Rheb in hippocampal neurons in vivo, we transfected neurons in the cornu ammonis 1 (CA1) region in normal adult rats with an adeno-associated virus containing the constitutively active human Rheb (hRheb(S16H)) and evaluated the effects on thrombin-induced neurotoxicity. Transduction with hRheb(S16H) significantly induced neurotrophic effects in hippocampal neurons through activation of mammalian target of rapamycin complex 1 (mTORC1) without side effects such as long-term potentiation impairment and seizures from the alteration of cytoarchitecture, and the expression of hRheb(S16H) prevented thrombin-induced neurodegeneration in vivo, an effect that was diminished by treatment with specific neutralizing antibodies against brain-derived neurotrophic factor (BDNF). In addition, our results showed that the basal mTORC1 activity might be insufficient to mediate the level of BDNF expression, but hRheb(S16H)-activated mTORC1 stimulated BDNF production in hippocampal neurons. These results suggest that viral vector transduction with hRheb(S16H) may have therapeutic value in the treatment of neurodegenerative diseases such as AD.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/biossíntese , Região CA1 Hipocampal/metabolismo , Proteínas Monoméricas de Ligação ao GTP/genética , Neurônios/metabolismo , Neuropeptídeos/genética , Transdução Genética/métodos , Animais , Anticorpos Neutralizantes/farmacologia , Fator Neurotrófico Derivado do Encéfalo/agonistas , Fator Neurotrófico Derivado do Encéfalo/antagonistas & inibidores , Fator Neurotrófico Derivado do Encéfalo/genética , Região CA1 Hipocampal/citologia , Região CA1 Hipocampal/efeitos dos fármacos , Dependovirus/genética , Dependovirus/metabolismo , Expressão Gênica , Vetores Genéticos/administração & dosagem , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Complexos Multiproteicos/agonistas , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neuropeptídeos/metabolismo , Proteína Enriquecida em Homólogo de Ras do Encéfalo , Ratos , Ratos Sprague-Dawley , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Trombina/antagonistas & inibidores , Trombina/toxicidadeRESUMO
BACKGROUND: Oxidative stress is one of the mechanisms underlying pathogenesis in neurodegenerative diseases such as Alzheimer's disease. Generally, oxidative stress represents cell toxicity; however, we recently found that oxidative stress promotes the expression of growth factor progranulin (PGRN) in HT22 murine hippocampus cells, thereby protecting the HT22 cells. In this study, we attempted to clarify whether a similar system exists in the other neuronal cell model, rat pheochromocytoma (PC12) cells. RESULTS: After confirming that high concentrations of hydrogen peroxide (H2O2; 100-250 µM) initiate PC12 cell death, we analyzed growth factor expressional changes after H2O2 treatment. We found, intriguingly, that gene expression of brain-derived neurotrophic factor (BDNF), but not PGRN was significantly induced by H2O2. Although little expression of the high affinity BDNF receptor tropomyosin-related kinase TrkB was observed in PC12 cells, expression of low affinity neurotrophin receptor, p75NTR, was clearly observed. This BDNF signaling appeared to contribute to PC12 cell protection, since PC12 cell death was significantly attenuated by BDNF treatment. CONCLUSIONS: Based on our results, we conclude that the induction of BDNF by subtoxic levels of H2O2 and its signaling may have roles in PC12 cell protection.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/genética , Regulação da Expressão Gênica , Peróxido de Hidrogênio/farmacologia , Animais , Fator Neurotrófico Derivado do Encéfalo/agonistas , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Morte Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas do Tecido Nervoso , Estresse Oxidativo , Células PC12 , Progranulinas , Ratos , Receptor trkB/genética , Receptor trkB/metabolismo , Receptores de Fatores de Crescimento , Receptores de Fator de Crescimento Neural/genética , Receptores de Fator de Crescimento Neural/metabolismo , Transdução de SinaisRESUMO
Amphotericin B (AmB) is a polyene antibiotic and reported to have therapeutic effects on prion diseases, in which the microglial activation has been suggested to play important roles by proliferating and producing various factors such as nitric oxide, proinflammatory cytokines, and so on. However, the therapeutic mechanism of AmB on prion diseases remains elusive. In the present study, we investigated the effects of AmB on cellular functions of rat primary cultured microglia. We found that AmB, similarly as lipopolysaccharide (LPS), could activate microglia to produce nitric oxide via inducible nitric oxide synthase. Both AmB and LPS also induced mRNA expressions of interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha in microglia. AmB also changed the expression levels of neurotrophic factors mRNAs. AmB and LPS significantly down-regulated the level of ciliary neurotrophic factor mRNA. However, AmB, but not LPS, significantly up-regulated the level of glial cell-line derived neurotrophic factor mRNA in microglia. In addition, brain-derived neurotrophic factor mRNA expression level was tending upward by treatment with AmB, but not with LPS. Taken together, these results suggest that AmB regulates the microglial activation in different manner from LPS and that microglia may participate in the therapeutic effects of AmB on prion diseases by controlling the expression and production of such mediators.
Assuntos
Anfotericina B/farmacologia , Gliose/tratamento farmacológico , Inflamação/tratamento farmacológico , Microglia/efeitos dos fármacos , Doenças Priônicas/tratamento farmacológico , Anfotericina B/uso terapêutico , Animais , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Fator Neurotrófico Derivado do Encéfalo/agonistas , Fator Neurotrófico Derivado do Encéfalo/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Citocinas/agonistas , Citocinas/genética , Fator Neurotrófico Derivado de Linhagem de Célula Glial/agonistas , Fator Neurotrófico Derivado de Linhagem de Célula Glial/genética , Gliose/metabolismo , Gliose/fisiopatologia , Inflamação/metabolismo , Inflamação/fisiopatologia , Interleucina-1beta/agonistas , Interleucina-1beta/genética , Interleucina-6/agonistas , Interleucina-6/genética , Microglia/metabolismo , Fatores de Crescimento Neural/agonistas , Fatores de Crescimento Neural/genética , Neurotoxinas/agonistas , Neurotoxinas/metabolismo , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase/efeitos dos fármacos , Óxido Nítrico Sintase/metabolismo , Doenças Priônicas/metabolismo , Doenças Priônicas/fisiopatologia , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Fator de Necrose Tumoral alfa/agonistas , Fator de Necrose Tumoral alfa/genética , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genéticaRESUMO
Tyrosine kinase receptor B (TrkB) mediates neurotrophic effects of brain-derived neurotrophic factor (BDNF) to increase neuronal survival, differentiation, synaptic plasticity, and neurogenesis. The therapeutic potential of TrkB activation using BDNF has been demonstrated well in several preclinical models of CNS diseases, validating TrkB as a promising drug target. Therefore, we aimed to develop TrkB-specific receptor agonists by using a monoclonal antibody approach. After generation of hybridoma clones and assessment of their binding and functional activity, we identified five mouse monoclonal antibodies that show highly selective binding to TrkB and that induce robust activation of TrkB signaling. Epitope mapping studies using competition analysis showed that each of the monoclonal antibodies recognizes a unique binding site on TrkB, some of which are distinct from BDNF docking sites. These antibodies behave as true agonists based on their ability to both activate proximal and secondary signaling molecules downstream of TrkB receptors and promote neuronal survival and neurite outgrowth. The binding affinities and the functional efficacy of these antibodies are comparable to those of BDNF, whereas they do not bind to the p75 low-affinity neurotrophin receptor at all. Therefore, they could represent novel reagents to explore the pathophysiological roles of TrkB and its potential therapeutic utility in treating CNS disorders.