RESUMO
Psychedelic compounds have potentially rapid, long-lasting anxiolytic, antidepressive and anti-inflammatory effects. We investigated whether the psychedelic compound (R)-2,5-dimethoxy-4-iodoamphetamine [(R)-DOI], a selective 5-HT2A receptor partial agonist, decreases stress-related behavior in male mice exposed to repeated social aggression. Additionally, we explored the likelihood that these behavioral changes are related to anti-inflammatory properties of [(R)-DOI]. Animals were subjected to the Stress Alternatives Model (SAM), an escapable social stress paradigm in which animals develop reactive coping strategies - remaining in the SAM arena (Stay) with a social aggressor, or dynamically initiated stress coping strategies that involve utilizing the escape holes (Escape) to avoid aggression. Mice expressing these behavioral phenotypes display behaviors like those in other social aggression models that separate animals into stress-vulnerable (as for Stay) or stress-resilient (as for Escape) groups, which have been shown to have distinct inflammatory responses to social stress. These results show that Stay animals have heightened cytokine gene expression, and both Stay and Escape mice exhibit plasma and neural concentrations of the inflammatory cytokine tumor necrosis factor-α (TNFα) compared to unstressed control mice. Additionally, these results suggest that a single administration of (R)-DOI to Stay animals in low doses, can increase stress coping strategies such as increasing attention to the escape route, promoting escape behavior, and reducing freezing during socially aggressive interaction in the SAM. Lower single doses of (R)-DOI, in addition to shifting behavior to suggest anxiolytic effects, also concomitantly reduce plasma and limbic brain levels of the inflammatory cytokine TNFα.
Assuntos
Adaptação Psicológica , Agressão , Anfetaminas , Alucinógenos , Estresse Psicológico , Animais , Masculino , Estresse Psicológico/tratamento farmacológico , Estresse Psicológico/metabolismo , Alucinógenos/administração & dosagem , Alucinógenos/farmacologia , Adaptação Psicológica/efeitos dos fármacos , Adaptação Psicológica/fisiologia , Camundongos , Agressão/efeitos dos fármacos , Agressão/fisiologia , Anfetaminas/farmacologia , Anfetaminas/administração & dosagem , Camundongos Endogâmicos C57BL , Fator de Necrose Tumoral alfa/metabolismo , Agonistas do Receptor 5-HT2 de Serotonina/farmacologia , Agonistas do Receptor 5-HT2 de Serotonina/administração & dosagem , Reação de Fuga/efeitos dos fármacos , Capacidades de EnfrentamentoRESUMO
Trophic factors are secreted proteins that can modulate neuronal integrity, structure, and function. Previous preclinical studies have shown synergistic effects on decreasing apoptosis and improving behavioral performance after stroke when combining two such trophic factors, erythropoietin (EPO) and insulin-like growth factor-1 (IGF-1). However, EPO can elevate the hematocrit level, which can be life-threatening for non-anemic individuals. A chemically engineered derivative of EPO, carbamoylated EPO (CEPO), does not impact hematological parameters but retains neurotrophic effects similar to EPO. To obtain insight into CEPO and IGF-1 combination signaling, we examined immediate early gene (IEG) expression after treatment with CEPO, IGF-1, or CEPO + IGF-1 in rat pheochromocytoma (PC-12) cells and found that combining CEPO and IGF-1 produced a synergistic increase in IEG expression. An in vivo increase in the protein expression of Npas4 and Nptx2 was also observed in the rat hippocampus. We also examined which kinase signaling pathways might be mediating these effects and found that while AKT inhibition did not alter the pattern of IEG expression, both ERK and JAK2 inhibition significantly decreased IEG expression. These results begin to define the molecular effects of combining CEPO and IGF-1 and indicate the potential for these trophic factors to produce positive, synergistic effects.
RESUMO
INTRODUCTION: Carbamoylated erythropoietin (CEPO) is a chemically engineered, nonhematopoietic derivative of erythropoietin (EPO) that retains its antidepressant and pro-cognitive effects, which are attributed to the increased expression of neurotrophic factors like brain derived neurotrophic factor (BDNF), in the central nervous system. However, the chemical modification process which produces CEPO from erythropoietin (EPO) requires pure EPO as raw material, is challenging to scale-up and can also cause batch-to-batch variability. To address these key limitations while retaining its behavioral effects, we designed, expressed and analyzed a triple, glutamine, substitution recombinant mimetic of CEPO, named QPO. METHODS AND MATERIALS: We employ a combination of computational structural biology, molecular, cellular and behavioral assays to design, produce, purify and test QPO. RESULTS: QPO was shown to be a nonhematopoietic polypeptide with significant antidepressant-like and pro-cognitive behavioral effects in rodent assays while significantly upregulating BDNF expression in-vitro and in-vivo. The in-silico binding affinity analysis of QPO bound to the EPOR/EPOR homodimer receptor shows significantly decreased binding to Active Site 2, but not Active Site 1, of EPOR. DISCUSSION: The results of the behavioral and gene expression analysis imply that QPO is a successful CEPO mimetic protein and potentially acts via a similar neurotrophic mechanism, making it a drug development target for psychiatric disorders. The decreased binding to Active Site 2 could imply that this active site is not involved in neuroactive signaling and could allow the development of a functional innate repair receptor (IRR) model. Substituting the three glutamine substitution residues with arginine (RPO) resulted in the loss of behavioral activity, indicating the importance of glutamine residues at those positions.
Assuntos
Antidepressivos/uso terapêutico , Desenvolvimento de Medicamentos , Transtornos Mentais/tratamento farmacológico , Fatores de Crescimento Neural/uso terapêutico , Animais , Antidepressivos/química , Antidepressivos/isolamento & purificação , Linhagem Celular Tumoral , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Fatores de Crescimento Neural/química , Fatores de Crescimento Neural/isolamento & purificação , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismoRESUMO
The two strains of inbred mice, BALB/c and C57BL/6, are widely used in pre-clinical psychiatry research due to their differences in stress susceptibility. Gene profiling studies in these strains have implicated the inflammation pathway as the main contributor to these differences. We focused our attention on female mice and tested their response to 5- or 10-day exposure to restraint stress. We examined the stress induced changes in the regulation of 11 inflammatory cytokine genes and 12 glutamate receptor genes in the hippocampus of female BALB/c and C57BL/6 mice using quantitative PCR. Elevated proinflammatory cytokine genes include Tumor Necrosis Factor alpha (TNFa), nuclear factor kappa-light-chain-enhancer of activated B cells (NFKB), Interleukin 1 alpha (IL1a), Interleukin 1 receptor (IL1R), Interleukin 10 receptor alpha subunit (IL10Ra), Interleukin 10 receptor beta subunit (IL10Rb), and tumor necrosis factor (TNF) super family members. Our results show that BALB/c and C57BL/6 mice differ in the genes induced in response to stress exposure and the level of gene regulation change. Our results show that the gene regulation in female BALB/c and C57BL/6 mice differs between strains in the genes regulated and the magnitude of the changes.
RESUMO
Erythropoietin (EPO), a cytokine molecule, is best-known for its role in erythropoiesis. Preclinical studies have demonstrated that EPO has robust neuroprotective effects that appear to be independent of erythropoiesis. It is also being clinically tested for the treatment of neuropsychiatric illnesses due to its behavioral actions. A major limitation of EPO is that long-term administration results in excessive red blood cell production and increased blood viscosity. A chemical modification of EPO, carbamoylated erythropoietin (CEPO), reproduces the behavioral response of EPO in animal models but does not stimulate erythropoiesis. The molecular mechanisms involved in the behavioral effects of CEPO are not known. To obtain molecular insight we examined CEPO induced gene expression in neuronal cells. PC-12 cells were treated with CEPO followed by genome-wide microarray analysis. We investigated the functional significance of the gene profile by unbiased bioinformatics analysis. The Ingenuity pathway analysis (IPA) software was employed. The results revealed activation of functions such as neuronal number and long-term potentiation. Regulated signaling cascades included categories such as neurotrophin, CREB, NGF and synaptic long-term potentiation signaling. Some of the regulated genes from these pathways are CAMKII, EGR1, FOS, GRIN1, KIF1B, NOTCH1. We also comparatively examined EPO and CEPO-induced gene expression for a subset of genes in the rat dentate gyrus. The CEPO gene profile shows the induction of genes and signaling cascades that have roles in neurogenesis and memory formation, mechanisms that can produce antidepressant and cognitive function enhancing activity.
Assuntos
Eritropoetina/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Fatores de Crescimento Neural/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Animais , Diferenciação Celular , Perfilação da Expressão Gênica , Microdissecção e Captura a Laser , Masculino , Análise em Microsséries , Fatores de Crescimento Neural/genética , Proteínas do Tecido Nervoso/genética , Sistema Nervoso/efeitos dos fármacos , Sistema Nervoso/metabolismo , Células PC12 , Carbamilação de Proteínas , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacosRESUMO
BACKGROUND: Erythropoietin (EPO), a pleiotropic cytokine, binds to its receptor (EPOR) in bone marrow, activating a signaling cascade that results in red blood cell proliferation. A recently discovered naturally occurring EPO mutation (R150Q) at active site 1 (AS1) of the protein was shown to attenuate its canonical downstream signaling, eliminating its hematopoietic effects and causing a fatal anemia. The purpose of this work was to analyze the EPO-EPOR complex computationally to provide a structural explanation for this signaling change. MATERIALS AND METHODS: Computational structural biology analyses and molecular dynamics simulations were used to determine key interaction differences between the R150Q mutant and the wild-type form of EPO. Both were compared to another variant mutated at the same position, R150E, which also lacks hematopoietic activity. RESULTS: The ligand-receptor interactions of the R150Q and R150E mutants showed significant variations in how they interacted with EPOR at AS1 of the EPO-EPOR complex. Both lost specific reported salt bridges previously associated with full complex activation. CONCLUSION: This work describes how the ligand-receptor interactions at AS1 of the EPO- EPOR complex respond to mutations at the 150th position. The interactions at AS1 were used to propose a potential mechanism by which the binding of EPO to the extracellular domain of EPOR influences its cytosolic domain and the resulting signaling cascade.
RESUMO
The inbred mouse strains, C57BL/6 and BALB/c have been used widely in preclinical psychiatric research. The differences in stress susceptibility of available strains has provided a useful platform to test pharmacological agents and behavioral responses. Previous brain gene profiling efforts have indicated that the inflammation and immune response gene pathway is the predominant gene network in the differential stress response of BALB/c and C57BL/6 mice. The implication is that a composite stress paradigm that includes a sequence of extended, varied and unpredictable stressors induces inflammation-related genes in the hippocampus. We hypothesized that the regulation of inflammation genes in the brain could constitute a primary stress response and tested this by employing a simple stress protocol, repeated exposure to the same stressor for 10 days, 2 h of restraint per day. We examined stress-induced regulation of 13 proinflammatory cytokine genes in male BALB/c and C57BL/6 mice using quantitative PCR. Elevated cytokine genes included tumor necrosis factor alpha (TNFα), interleukin 6 (IL6), interleukin 10 (IL10), tumor necrosis factor (TNF) super family members and interleukin 1 receptor 1 (IL1R1). In addition, we examined restraint stress-induced regulation of 12 glutamate receptor genes in both strains. Our results show that restraint stress is sufficient to elevate the expression of inflammation-related genes in the hippocampus of both BABLB/c and C57BL/6 mice, but they differ in the genes that are induced and the magnitude of change. Cell types that are involved in this response include endothelial cells and astrocytes. Lay summary Repeated exposure to a simple restraint stress altered the activities of genes involved in inflammation and the functions of the excitatory neurotransmitter, glutamate. These changes in the hippocampus of the mouse brain showed differences that were dependent on the strain of mice and the length of the stress exposure. The effects of stress on activity of these genes may lead to alterations in behavior.
Assuntos
Regulação da Expressão Gênica , Hipocampo/metabolismo , Inflamação/metabolismo , Receptores de Glutamato/metabolismo , Estresse Psicológico/metabolismo , Animais , Inflamação/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Receptores de Glutamato/genética , Restrição Física , Especificidade da Espécie , Estresse Psicológico/genéticaRESUMO
Overexpression of the oncoprotein mortalin in cancer cells and its protein partners enables mortalin to promote multiple oncogenic signaling pathways and effectively antagonize chemotherapy-induced cell death. A UBX-domain-containing protein, UBXN2A, acts as a potential mortalin inhibitor. This current study determines whether UBXN2A effectively binds to and occupies mortalin's binding pocket, resulting in a direct improvement in the tumor's sensitivity to chemotherapy. Molecular modeling of human mortalin's binding pocket and its binding to the SEP domain of UBXN2A followed by yeast two-hybrid and His-tag pull-down assays revealed that three amino acids (PRO442, ILE558, and LYS555) within the substrate-binding domain of mortalin are crucial for UBXN2A binding to mortalin. As revealed by chase experiments in the presence of cycloheximide, overexpression of UBXN2A seems to interfere with the mortalin-CHIP E3 ubiquitin ligase and consequently suppresses the C-terminus of the HSC70-interacting protein (CHIP)-mediated destabilization of p53, resulting in its stabilization in the cytoplasm and upregulation in the nucleus. Overexpression of UBXN2A causes a significant inhibition of cell proliferation and the migration of colon cancer cells. We silenced UBXN2A in the human osteosarcoma U2OS cell line, an enriched mortalin cancer cell, followed by a clinical dosage of the chemotherapeutic agent 5-fluorouracil (5-FU). The UBXN2A knockout U2OS cells revealed that UBXNA is essential for the cytotoxic effect achieved by 5-FU. UBXN2A overexpression markedly increased the apoptotic response of U2OS cells to the 5-FU. In addition, silencing of UBXN2A protein suppresses apoptosis enhanced by UBXN2A overexpression in U2OS. The knowledge gained from this study provides insights into the mechanistic role of UBXN2A as a potent mortalin inhibitor and as a potential chemotherapy sensitizer for clinical application.
Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Fluoruracila/farmacologia , Proteínas de Choque Térmico HSP70/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Ubiquitinas/metabolismo , Apoptose/efeitos dos fármacos , Sítios de Ligação , Linhagem Celular Tumoral , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Proteínas de Choque Térmico HSP70/química , Humanos , Simulação de Acoplamento Molecular , Neoplasias/genética , Neoplasias/patologia , Osteossarcoma/tratamento farmacológico , Osteossarcoma/genética , Osteossarcoma/metabolismo , Osteossarcoma/patologia , Ligação Proteica , Domínios Proteicos , Interferência de RNA , Proteína Supressora de Tumor p53/metabolismo , Ubiquitinas/química , Ubiquitinas/genéticaRESUMO
Major depressive disorder (MDD) has been linked to changes in function and activity of the hippocampus, one of the central limbic regions involved in regulation of emotions and mood. The exact cellular and molecular mechanisms underlying hippocampal plasticity in response to stress are yet to be fully characterized. In this study, we examined the genetic profile of micro-dissected subfields of post-mortem hippocampus from subjects diagnosed with MDD and comparison subjects matched for sex, race and age. Gene expression profiles of the dentate gyrus and CA1 were assessed by 48K human HEEBO whole genome microarrays and a subgroup of identified genes was confirmed by real-time polymerase chain reaction (qPCR). Pathway analysis revealed altered expression of several gene families, including cytoskeletal proteins involved in rearrangement of neuronal processes. Based on this and evidence of hippocampal neuronal atrophy in MDD, we focused on the expression of cytoskeletal, synaptic and glutamate receptor genes. Our findings demonstrate significant dysregulation of synaptic function/structure related genes SNAP25, DLG2 (SAP93), and MAP1A, and 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl)propanoic acid receptor subunit genes GLUR1 and GLUR3. Several of these human target genes were similarly dysregulated in a rat model of chronic unpredictable stress and the effects reversed by antidepressant treatment. Together, these studies provide new evidence that disruption of synaptic and glutamatergic signalling pathways contribute to the pathophysiology underlying MDD and provide interesting targets for novel therapeutic interventions.
Assuntos
Transtorno Depressivo Maior/genética , Hipocampo/metabolismo , Hipocampo/patologia , Proteínas do Tecido Nervoso/genética , Receptores de Glutamato/genética , Sinapses/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Transtorno Depressivo Maior/metabolismo , Transtorno Depressivo Maior/patologia , Feminino , Regulação da Expressão Gênica , Guanilato Quinases/biossíntese , Guanilato Quinases/genética , Humanos , Masculino , Proteínas Associadas aos Microtúbulos/biossíntese , Proteínas Associadas aos Microtúbulos/genética , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/biossíntese , Ratos , Ratos Sprague-Dawley , Receptores de AMPA/biossíntese , Receptores de AMPA/genética , Receptores de Glutamato/biossíntese , Sinapses/metabolismo , Proteína 25 Associada a Sinaptossoma/biossíntese , Proteína 25 Associada a Sinaptossoma/genética , Proteínas Supressoras de Tumor/biossíntese , Proteínas Supressoras de Tumor/genéticaRESUMO
BACKGROUND: Chronic electroconvulsive seizure (chr-ECS), one of the most efficacious treatments for depressed patients, increases the levels of transcription factor cyclic adenosine monophosphate response element binding protein (CREB) in rodent models and mediates the effects of chronic antidepressant treatment. The objective of this study was to determine the changes in CREB occupancy at gene promoters and subsequent gene expression changes induced by chr-ECS. METHODS: We use chromatin immunoprecipitation followed by microarray analysis to identify CREB binding promoters that are influenced by chr-ECS (n = 6/group). Selected genes are confirmed by secondary validation techniques, and the functional significance of one target was tested in behavioral models (n = 8/group) by viral mediated inhibition of gene expression. RESULTS: The results demonstrate that chr-ECS enhances CREB binding and activity at a select population of genes in the hippocampus, effects that could contribute to the efficacy of chr-ECS. Viral vector-mediated inhibition of one of the CREB-target genes regulated by chr-ECS, Fzd6, produced anxiety and depressive-like effects in behavioral models of depression. CONCLUSIONS: The results identify multiple gene targets differentially regulated by CREB binding in the hippocampus after chr-ECS and demonstrate the role of Fzd6, a Wnt receptor in behavioral models of depression.
Assuntos
Depressão/genética , Eletroconvulsoterapia , Receptores Frizzled/genética , Animais , Proteína de Ligação a CREB , Imunoprecipitação da Cromatina , Depressão/terapia , Modelos Animais de Doenças , Reação de Fuga/fisiologia , Jejum , Preferências Alimentares/fisiologia , Receptores Frizzled/metabolismo , Regulação da Expressão Gênica/fisiologia , Vetores Genéticos/fisiologia , Hipocampo , Humanos , Masculino , Aprendizagem em Labirinto , Análise em Microsséries , Atividade Motora/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/uso terapêutico , Ratos , Ratos Sprague-Dawley , Fatores de TempoRESUMO
The lifetime prevalence (â¼16%) and the economic burden ($100 billion annually) associated with major depressive disorder (MDD) make it one of the most common and debilitating neurobiological illnesses. To date, the exact cellular and molecular mechanisms underlying the pathophysiology of MDD have not been identified. Here we use whole-genome expression profiling of postmortem tissue and show significantly increased expression of mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1, encoded by DUSP1, but hereafter called MKP-1) in the hippocampal subfields of subjects with MDD compared to matched controls. MKP-1, also known as dual-specificity phosphatase-1 (DUSP1), is a member of a family of proteins that dephosphorylate both threonine and tyrosine residues and thereby serves as a key negative regulator of the MAPK cascade, a major signaling pathway involved in neuronal plasticity, function and survival. We tested the role of altered MKP-1 expression in rat and mouse models of depression and found that increased hippocampal MKP-1 expression, as a result of stress or viral-mediated gene transfer, causes depressive behaviors. Conversely, chronic antidepressant treatment normalizes stress-induced MKP-1 expression and behavior, and mice lacking MKP-1 are resilient to stress. These postmortem and preclinical studies identify MKP-1 as a key factor in MDD pathophysiology and as a new target for therapeutic interventions.
Assuntos
Depressão/enzimologia , Fosfatase 1 de Especificidade Dupla/metabolismo , Animais , Antidepressivos/farmacologia , Comportamento Animal/efeitos dos fármacos , Dependovirus/efeitos dos fármacos , Dependovirus/genética , Depressão/genética , Modelos Animais de Doenças , Feminino , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos , Camundongos Knockout , Análise de Sequência com Séries de Oligonucleotídeos , Mudanças Depois da Morte , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND: Despite recent interest in glycogen synthase kinase-3beta (GSK-3beta) as a target for the treatment of mood disorders, there has been very little work related to these illnesses on the upstream signaling molecules that regulate this kinase as well as downstream targets. METHODS: With a focused microarray approach we examined the influence of different classes of antidepressants on Wnt signaling that controls GSK-3beta activity as well as the transcription factors that contribute to the actions of GSK-3beta. RESULTS: The results demonstrate that Wnt2 is a common target of different classes of antidepressants and also show differential regulation of Wnt-GSK-3beta signaling genes. Increased expression and function of Wnt2 was confirmed by secondary measures. Moreover, with a viral vector approach we demonstrate that increased expression of Wnt2 in the hippocampus is sufficient to produce antidepressant-like behavioral actions in well-established models of depression and treatment response. CONCLUSIONS: These findings demonstrate that Wnt2 expression and signaling is a common target of antidepressants and that increased Wnt2 is sufficient to produce antidepressant effects.
Assuntos
Antidepressivos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Proteína Wnt2/biossíntese , Animais , Antidepressivos/administração & dosagem , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Dependovirus/genética , Eletrochoque/métodos , Regulação da Expressão Gênica/genética , Técnicas de Transferência de Genes , Vetores Genéticos , Hipocampo/metabolismo , Masculino , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Proteína Wnt2/fisiologiaRESUMO
BACKGROUND: Postpartum depression (PPD) affects approximately 10% to 20% of women during the first 4 weeks of the postpartum period and is characterized by labile mood with prominent anxiety and irritability, insomnia, and depressive mood. During the postpartum period, elevated ovarian hormones abruptly decrease to the early follicular phase levels that are postulated to play a major role in triggering PPD. However, the underlying neurobiological mechanisms that contribute to PPD have not been determined. METHODS: In the present study, we examined the effect of ovarian steroids, administered at levels that occur during human pregnancy followed by rapid withdrawal to simulate postpartum conditions, on behavior and gene expression in the rat. RESULTS: The results of behavioral testing reveal that the hormone-simulated postpartum treatment results in the development of a phenotype relevant to PPD, including vulnerability for helplessness, increased anxiety, and aggression. Real-time quantitative polymerase chain reaction (PCR) demonstrated transient regulation of several genes, including Ca(2+)/calmodulin-dependent protein kinase II (CAMKII), serotonin transporter (SERT), myocyte enhancer factor 2A (MEF2A), brain-derived neurotrophic factor (BDNF), gamma-aminobutyric acid type A receptor alpha 4 (GABAARA4), mothers against decapentaplegic homolog 4 (SMAD4), and aquaporin 4 (AQP4) that could underlie these behavioral effects. CONCLUSIONS: These studies provide an improved understanding of the effects of withdrawal from high doses of ovarian hormones on behavior and gene expression changes in the brain that could contribute to the pathophysiology of PPD.
Assuntos
Comportamento Animal/fisiologia , Depressão Pós-Parto , Regulação da Expressão Gênica/fisiologia , Período Pós-Parto/metabolismo , Esteroides/metabolismo , Análise de Variância , Animais , Aquaporina 4/genética , Aquaporina 4/metabolismo , Comportamento Animal/efeitos dos fármacos , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Depressão Pós-Parto/etiologia , Depressão Pós-Parto/genética , Depressão Pós-Parto/psicologia , Modelos Animais de Doenças , Estradiol/farmacologia , Comportamento Exploratório/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Desamparo Aprendido , Fatores de Transcrição MEF2 , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Fatores de Regulação Miogênica/genética , Fatores de Regulação Miogênica/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Ovariectomia/métodos , Ratos , Ratos Sprague-Dawley , Receptores de GABA-A/genética , Receptores de GABA-A/metabolismo , NataçãoRESUMO
Exercise has many health benefits, including antidepressant actions in depressed human subjects, but the mechanisms underlying these effects have not been elucidated. We used a custom microarray to identify a previously undescribed profile of exercise-regulated genes in the mouse hippocampus, a brain region implicated in mood and antidepressant response. Pathway analysis of the regulated genes shows that exercise upregulates a neurotrophic factor signaling cascade that has been implicated in the actions of antidepressants. One of the most highly regulated target genes of exercise and of the growth factor pathway is the gene encoding the VGF nerve growth factor, a peptide precursor previously shown to influence synaptic plasticity and metabolism. We show that administration of a synthetic VGF-derived peptide produces a robust antidepressant response in mice and, conversely, that mutation of VGF in mice produces the opposite effects. The results suggest a new role for VGF and identify VGF signaling as a potential therapeutic target for antidepressant drug development.
Assuntos
Antidepressivos/farmacologia , Transtorno Depressivo/metabolismo , Exercício Físico , Perfilação da Expressão Gênica , Hipocampo/metabolismo , Neuropeptídeos/metabolismo , Condicionamento Físico Animal , Animais , Desenho de Fármacos , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Fatores de Crescimento Neural , Análise de Sequência com Séries de Oligonucleotídeos , Células PC12 , RatosRESUMO
Electroconvulsive shock (ECS) is the most effective treatment for depression, but the mechanism underlying the therapeutic action of this treatment is still unknown. To better understand the molecular changes that may be necessary for the clinical effectiveness of ECS we have combined the technologies of gene expression profiling using cDNA microarrays with T7-based RNA amplification and laser microdissection to identify regulated genes in the dentate gyrus granule cell layer of the hippocampus. We have identified genes previously reported to be up-regulated following ECS, including brain-derived neurotrophic factor, neuropeptide Y, and thyrotrophin releasing hormone, as well as several novel genes. Notably, we have identified additional genes that are known to be involved in neuroprotection, such as growth arrest DNA damage inducible beta (Gadd45beta), and the excitatory amino acid transporter-1 (EAAC1/Slc1A1). In addition, via in situ hybridization we show that EAAC1 is specifically up-regulated in the dentate gyrus, but not in other hippocampal subfields. This study demonstrates the utility of microarray analysis of microdissected subregions of limbic brain regions and identifies novel ECS-regulated genes.
Assuntos
Giro Denteado/metabolismo , Transtorno Depressivo/terapia , Eletrochoque , Proteínas do Tecido Nervoso/genética , Neurônios/metabolismo , Animais , Antígenos de Diferenciação/análise , Antígenos de Diferenciação/genética , Antígenos de Diferenciação/metabolismo , Fator Neurotrófico Derivado do Encéfalo/análise , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Transtorno Depressivo/genética , Transtorno Depressivo/metabolismo , Modelos Animais de Doenças , Transportador 3 de Aminoácido Excitatório/análise , Transportador 3 de Aminoácido Excitatório/genética , Transportador 3 de Aminoácido Excitatório/metabolismo , Expressão Gênica/fisiologia , Perfilação da Expressão Gênica/métodos , Ácido Glutâmico/metabolismo , Masculino , Proteínas do Tecido Nervoso/análise , Proteínas do Tecido Nervoso/metabolismo , Neuropeptídeo Y/análise , Neuropeptídeo Y/genética , Neuropeptídeo Y/metabolismo , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Hormônio Liberador de Tireotropina/análise , Hormônio Liberador de Tireotropina/genética , Hormônio Liberador de Tireotropina/metabolismoRESUMO
Electroconvulsive seizure has a proven therapeutic application in the treatment of severe depression and treatment-resistant depression. Despite the efficacy of electroconvulsive seizure as a non-chemical antidepressant treatment, the mechanism of action is unclear. Elevation in hippocampal trophic factor expression and concomitant cellular proliferation are thought to play a role in its action. We examined whether the reported induction of angiogenic factors and endothelial cell proliferation leads to an increase in vascular density. Two hippocampal regions, the dentate gyrus and the stratum lacunosum moleculare (SLM), were examined employing a combination of vascular density quantification, angiogenic gene expression analysis and immunohistochemistry. A 6% increase in vascular density was observed in the dentate gyrus but this did not achieve statistical significance. The SLM of the hippocampus exhibited a robust 20-30% increase in vascular density and was accompanied by an increase in expression of inhibitor of differentiation-3. There was also an induction of the angiogenesis markers alphaVbeta3 integrin and Del1. Increases in the vascular density of the SLM could be in response to enhanced metabolic activity in this region. This is supported by the induction of glutamine synthetase and the glutamate transporter GLT1.
Assuntos
Vasos Sanguíneos/metabolismo , Transtorno Depressivo/terapia , Eletroconvulsoterapia , Hipocampo/irrigação sanguínea , Hipocampo/metabolismo , Neovascularização Fisiológica/fisiologia , Animais , Biomarcadores/metabolismo , Proteínas de Ligação ao Cálcio , Proteínas de Transporte/metabolismo , Moléculas de Adesão Celular , Giro Denteado/irrigação sanguínea , Giro Denteado/metabolismo , Transtorno Depressivo/fisiopatologia , Transportador 2 de Aminoácido Excitatório/metabolismo , Glutamato-Amônia Ligase/metabolismo , Ácido Glutâmico/metabolismo , Proteínas Inibidoras de Diferenciação/metabolismo , Integrina alfaVbeta3/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular , Masculino , Ratos , Ratos Sprague-Dawley , Regulação para Cima/fisiologiaRESUMO
Previous studies demonstrate that chronic, but not acute electroconvulsive seizures (ECS), increases levels of deltaFosB, a long-lasting transcription factor, in the hippocampus, and this effect correlates with the slow onset and long-lasting clinical effects of antidepressant treatment. To understand how deltaFosB mediates long-term plasticity in the hippocampus, we analyzed the gene expression profile of inducible transgenic mice expressing deltaFosB with a highly sensitive microarray assay and a customized computer analysis program. The CCAAT-enhancing binding protein-beta (C/EBPbeta) was identified as one of the genes downregulated by deltaFosB in the hippocampus. The downregulation of C/EBPbeta in the inducible deltaFosB transgenic mice was confirmed by other quantitative assays including real-time RT-PCR and low density dot blotting. Analysis of the C/EBPbeta expression in the hippocampus of rats treated with ECS revealed that the C/EBPbeta mRNA was also downregulated by chronic, but not acute ECS administration, the most effective treatment for depression. Given the reported role of C/EBPbeta in behavioral conditioning models, it is possible that the deltaFosB-mediated downregulation of C/EBPbeta in the hippocampus may be a molecular mechanism by which antidepressants alleviate some of the symptoms of depressed patients.
Assuntos
Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Regulação para Baixo , Eletrochoque , Proteínas Proto-Oncogênicas c-fos/metabolismo , Animais , Southern Blotting , Western Blotting , Proteína beta Intensificadora de Ligação a CCAAT/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Hipocampo/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-fos/genética , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodosRESUMO
BACKGROUND: Beta-catenin was discovered as a cytoskeletal protein, constituting a link between the cadherins to the actin cytoskeleton. Aside from this function, beta-catenin is a key effector molecule in the Wnt signaling pathway, serving as a downstream transcription factor. METHODS: In this study, we examined the influence of electroconvulsive seizures (ECS) on the expression of beta-catenin, as well as expression of Wnt-2, in rat hippocampus. Repeated administration of generalized seizures increased levels of beta-catenin immunoreactivity in the subgranular zone of the hippocampus. To assess the relationship of beta-catenin to cell division in the dentate gyrus of the adult rat hippocampus, colocalization of beta-catenin with a marker of cell division was examined. RESULTS: Beta-catenin immunoreactivity was consistently localized in newborn cells in this region, indicating a possible role in cell division and differentiation in adult hippocampus. We also found that ECS treatment significantly increased levels of Wnt-2, one of the ligands that activates beta-catenin signaling. CONCLUSIONS: These results demonstrate that ECS increases Wnt-beta-catenin signaling and suggest that this pathway could mediate in part the neuronal adaptations underlying the therapeutic action of this treatment paradigm.
Assuntos
Proteínas do Citoesqueleto/metabolismo , Eletrochoque/métodos , Hipocampo/metabolismo , Transativadores/metabolismo , Animais , Western Blotting , Bromodesoxiuridina/metabolismo , Contagem de Células , Hipocampo/citologia , Hipocampo/efeitos da radiação , Imuno-Histoquímica/métodos , Hibridização In Situ/métodos , Masculino , Proteínas Proto-Oncogênicas/metabolismo , RNA Mensageiro/biossíntese , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/fisiologia , Transdução de Sinais/efeitos da radiação , Frações Subcelulares/metabolismo , Frações Subcelulares/efeitos da radiação , Tempo , Fatores de Tempo , Regulação para Cima/efeitos da radiação , Proteína Wnt2 , beta CateninaRESUMO
Activation of the cAMP/protein kinase A (PKA) pathway has been proposed as a mechanism for improving age-related cognitive deficits based on studies of hippocampal function. However, normal aging also afflicts prefrontal cortical cognitive functioning. Here, we report that agents that increase PKA activity impair rather than improve prefrontal cortical function in aged rats and monkeys with prefrontal cortical deficits. Conversely, PKA inhibition ameliorates prefrontal cortical cognitive deficits. Western blot and immunohistochemical analyses of rat brain further indicate that the cAMP/PKA pathway becomes disinhibited in the prefrontal cortex with advancing age. These data demonstrate that PKA inhibition, rather than activation, is the appropriate strategy for restoring prefrontal cortical cognitive abilities in the elderly.