RESUMO
(R,S)-ketamine elicits rapid-acting and sustained antidepressant actions in treatment-resistant patients with depression. (R)-ketamine produces longer-lasting antidepressant effects than (S)-ketamine in rodents; however, the precise molecular mechanisms underlying antidepressant actions of (R)-ketamine remain unknown. Using isobaric Tag for Relative and Absolute Quantification, we identified nuclear receptor-binding protein 1 (NRBP1) that could contribute to different antidepressant-like effects of the two enantiomers in chronic social defeat stress (CSDS) model. NRBP1 was localized in the microglia and neuron, not astrocyte, of mouse medial prefrontal cortex (mPFC). (R)-ketamine increased the expression of NRBP1, brain-derived neurotrophic factor (BDNF), and phosphorylated cAMP response element binding protein (p-CREB)/CREB ratio in primary microglia cultures thorough the extracellular signal-regulated kinase (ERK) activation. Furthermore, (R)-ketamine could activate BDNF transcription through activation of CREB as well as MeCP2 (methyl-CpG binding protein 2) suppression in microglia. Single intracerebroventricular (i.c.v.) injection of CREB-DNA/RNA heteroduplex oligonucleotides (CREB-HDO) or BDNF exon IV-HDO blocked the antidepressant-like effects of (R)-ketamine in CSDS susceptible mice. Moreover, microglial depletion by colony-stimulating factor 1 receptor (CSF1R) inhibitor PLX3397 blocked the antidepressant-like effects of (R)-ketamine in CSDS susceptible mice. In addition, inhibition of microglia by single i.c.v. injection of mannosylated clodronate liposomes (MCLs) significantly blocked the antidepressant-like effects of (R)-ketamine in CSDS susceptible mice. Finally, single i.c.v. injection of CREB-HDO, BDNF exon IV-HDO or MCLs blocked the beneficial effects of (R)-ketamine on the reduced dendritic spine density in the mPFC of CSDS susceptible mice. These data suggest a novel ERK-NRBP1-CREB-BDNF pathways in microglia underlying antidepressant-like effects of (R)-ketamine.
Assuntos
Ketamina , Animais , Antidepressivos/farmacologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Depressão/tratamento farmacológico , Depressão/metabolismo , MAP Quinases Reguladas por Sinal Extracelular , Humanos , Ketamina/farmacologia , Ketamina/uso terapêutico , Camundongos , Camundongos Endogâmicos C57BL , Microglia/metabolismo , Receptores Citoplasmáticos e Nucleares , Estresse Psicológico/tratamento farmacológico , Estresse Psicológico/metabolismo , Proteínas de Transporte VesicularRESUMO
Antisense oligonucleotide (ASO)-based therapy is one of the next-generation therapy, especially targeting neurological disorders. Many cases of ASO-dependent gene expression suppression have been reported. Recently, we developed a tocopherol conjugated DNA/RNA heteroduplex oligonucleotide (Toc-HDO) as a new type of drug. Toc-HDO is more potent, stable, and efficiently taken up by the target tissues compared to the parental ASO. However, the detailed mechanisms of Toc-HDO, including its binding proteins, are unknown. Here, we developed native gel shift assays with fluorescence-labeled nucleic acids samples extracted from mice livers. These assays revealed two Toc-HDO binding proteins, annexin A5 (ANXA5) and carbonic anhydrase 8 (CA8). Later, we identified two more proteins, apurinic/apyrimidinic endodeoxyribonuclease 1 (APEX1) and flap structure-specific endonuclease 1 (FEN1) by data mining. shRNA knockdown studies demonstrated that all four proteins regulated Toc-HDO activity in Hepa1-6, mouse hepatocellular cells. In vitro binding assays and fluorescence polarization assays with purified recombinant proteins characterized the identified proteins and pull-down assays with cell lysates demonstrated the protein binding to the Toc-HDO and ASO in a biological environment. Taken together, our findings provide a brand new molecular biological insight as well as future directions for HDO-based disease therapy.
Assuntos
Inativação Gênica , Oligonucleotídeos Antissenso/metabolismo , Animais , Anexina A5/metabolismo , Biomarcadores Tumorais/metabolismo , Anidrases Carbônicas/metabolismo , Linhagem Celular , Centrifugação com Gradiente de Concentração , DNA , DNA Liase (Sítios Apurínicos ou Apirimidínicos)/metabolismo , Endonucleases Flap/metabolismo , Polarização de Fluorescência , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/metabolismo , Oligonucleotídeos Antissenso/química , RNA , RNA Interferente Pequeno , alfa-TocoferolRESUMO
Since its initial identification in 1986, Lyme disease has been clinically diagnosed in 29 provinces in China; however, national incidence data are lacking. To summarize Lyme disease seropositivity data among persons across China, we conducted a systematic literature review of Chinese- and English-language journal articles published during 2005â2020. According to 72 estimates that measured IgG by using a diagnostic enzyme-linked assay (EIA) alone, the seropositivity point prevalence with a fixed-effects model was 9.1%. A more conservative 2-tier testing approach of EIA plus a confirmatory Western immunoblot (16 estimates) yielded seropositivity 1.8%. Seropositivity by EIA for high-risk exposure populations was 10.0% and for low-risk exposure populations was 4.5%; seropositivity was highest in the northeastern and western provinces. Our analysis confirms Lyme disease prevalence, measured by seropositivity, in many Chinese provinces and populations at risk. This information can be used to focus prevention measures in provinces where seropositivity is high.
Assuntos
Borrelia burgdorferi , Doença de Lyme , Humanos , Doença de Lyme/diagnóstico , Doença de Lyme/epidemiologia , Western Blotting , Prevalência , China/epidemiologiaRESUMO
Sulforaphane (SFN) is an organic isothiocyanate and an NF-E2-related factor-2 (Nrf2) inducer that exerts prophylactic effects on depression-like behavior in mice. However, the underlying mechanisms remain poorly understood. Brain-derived neurotrophic factor (BDNF), a neurotrophin, is widely accepted for its antidepressant effects and role in stress resilience. Here, we show that SFN confers stress resilience via BDNF upregulation and changes in abnormal dendritic spine morphology in stressed mice, which is accompanied by rectifying the irregular levels of inflammatory cytokines. Mechanistic studies demonstrated that SFN activated Nrf2 to promote BDNF transcription by binding to the exon I promoter, which is associated with increased Nrf2, and decreased methyl-CpG binding protein-2 (MeCP2), a transcriptional suppressor of BDNF, in BV2 microglial cells. Furthermore, SFN inhibited the pro-inflammatory phenotype and activated the anti-inflammatory phenotype of microglia, which was associated with increased Nrf2 and decreased MeCP2 expression in microglia of stressed mice. Hence, our findings support that Nrf2 induces BDNF transcription via upregulation of Nrf2 and downregulation of MeCP2 in microglia, which is associated with changes in the morphology of damaged dendritic spines in stressed mice. Meanwhile, the data presented here provide evidence for the application of SFN as a candidate for the prevention and intervention of depression.
Assuntos
Fator Neurotrófico Derivado do Encéfalo , Microglia , Animais , Anti-Inflamatórios/farmacologia , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Isotiocianatos/farmacologia , Isotiocianatos/uso terapêutico , Camundongos , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , SulfóxidosRESUMO
Uncoupling protein-1 (UCP1), located at the inner membrane of mitochondria, is expressed primarily in brown adipose tissue and mediates the permeability of protons through the inner mitochondrial membrane. This research examines whether human UCP1 can uncouple oxidative phosphorylation in E. coli. Recombinant human UCP1 that includes an N terminus signal peptide for the bacterial inner membrane was expressed in E. coli. Our testing showed that UCP1 functions as a proton transporter in the bacterial membrane, increasing its permeability, decrease ATP synthesis at neutral pH and reducing the viability of E. coli in markedly acidic environments. These results suggest that UCP1 can uncouple oxidative phosphorylation in E. coli. The decreased acid resistance (AR) of E. coli with UCP1 expressed in the membranes confirmed that oxidative phosphorylation plays a role in AR through the pumping of protons to regulate the intracellular pH, and demonstrate that UCP1 can be used as an uncoupler protein for bacterial metabolic research.
Assuntos
Escherichia coli , Proteínas Mitocondriais , Escherichia coli/genética , Escherichia coli/metabolismo , Humanos , Canais Iônicos/genética , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Proteína Desacopladora 1/genéticaRESUMO
Depression is a severe and chronic psychiatric disease, affecting 350 million subjects worldwide. Although multiple antidepressants have been used in the treatment of depressive symptoms, their beneficial effects are limited. The soluble epoxide hydrolase (sEH) plays a key role in the inflammation that is involved in depression. Thus, we examined here the role of sEH in depression. In both inflammation and social defeat stress models of depression, a potent sEH inhibitor, TPPU, displayed rapid antidepressant effects. Expression of sEH protein in the brain from chronically stressed (susceptible) mice was higher than of control mice. Furthermore, expression of sEH protein in postmortem brain samples of patients with psychiatric diseases, including depression, bipolar disorder, and schizophrenia, was higher than controls. This finding suggests that increased sEH levels might be involved in the pathogenesis of certain psychiatric diseases. In support of this hypothesis, pretreatment with TPPU prevented the onset of depression-like behaviors after inflammation or repeated social defeat stress. Moreover, sEH KO mice did not show depression-like behavior after repeated social defeat stress, suggesting stress resilience. The sEH KO mice showed increased brain-derived neurotrophic factor (BDNF) and phosphorylation of its receptor TrkB in the prefrontal cortex, hippocampus, but not nucleus accumbens, suggesting that increased BDNF-TrkB signaling in the prefrontal cortex and hippocampus confer stress resilience. All of these findings suggest that sEH plays a key role in the pathophysiology of depression, and that epoxy fatty acids, their mimics, as well as sEH inhibitors could be potential therapeutic or prophylactic drugs for depression.
Assuntos
Depressão/tratamento farmacológico , Epóxido Hidrolases/antagonistas & inibidores , Epóxido Hidrolases/genética , Compostos de Fenilureia/farmacologia , Piperidinas/farmacologia , Estresse Psicológico/genética , Animais , Antidepressivos/farmacologia , Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Depressão/metabolismo , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacocinética , Inibidores Enzimáticos/farmacologia , Epóxido Hidrolases/metabolismo , Humanos , Inflamação/complicações , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oxilipinas/metabolismo , Compostos de Fenilureia/farmacocinética , Piperidinas/farmacocinética , Ratos Mutantes , Comportamento Social , Estresse Psicológico/tratamento farmacológicoRESUMO
The transcription factor Keap1-Nrf2 signaling plays a key role in the oxidative stress which is involved in psychiatric disorders. In the learned helplessness (LH) paradigm, protein levels of Keap1 and Nrf2 in the prefrontal cortex and dentate gyrus of hippocampus from LH (susceptible) rats were lower than control and non-LH (resilience) rats. Furthermore, protein expressions of Keap1 and Nrf2 in the parietal cortex from major depressive disorder, schizophrenia, and bipolar disorder were lower than controls. These results suggest that Keap1-Nrf2 signaling might contribute to stress resilience which plays a key role in the pathophysiology of psychiatric disorders.
Assuntos
Encéfalo/metabolismo , Eletrochoque/efeitos adversos , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Transdução de Sinais/fisiologia , Estresse Psicológico/patologia , Análise de Variância , Animais , Modelos Animais de Doenças , Regulação da Expressão Gênica/fisiologia , Desamparo Aprendido , Humanos , Masculino , Transtornos Mentais/metabolismo , Transtornos Mentais/patologia , Ratos , Ratos Sprague-Dawley , Estresse Psicológico/etiologia , Fatores de TempoRESUMO
Background: Similar to the N-methyl-D-aspartate receptor antagonist ketamine, the metabotropic glutamate 2/3 receptor antagonist, MGS0039, shows antidepressant effects. However, there are no reports comparing these 2 compounds in the social defeat stress model of depression. Methods: We examined the effects of MGS0039 (1 mg/kg) and ketamine (10 mg/kg) on depression-like behavior in susceptible mice after repeated social defeat stress. Protein levels of brain-derived neurotrophic factor, TrkB, phospho-TrkB, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (GluA1), postsynaptic density protein 95, and dendritic spine density in selected brain regions were measured. Results: In the tail suspension and forced swimming tests, both MGS0039 and ketamine significantly attenuated the increased immobility time observed in susceptible mice, compared with vehicle-treated animals, 1 or 2 days after a single dose of drug. In the sucrose preference test, both compounds significantly improved the reduced preference typically seen in susceptible mice at 3 to 7 days after a single dose of drug. Western-blot analyses showed that similar to ketamine, MGS0039 significantly attenuated the reduced brain-derived neurotrophic factor, phospho-TrkB/TrkB ratio, GluA1 and postsynaptic density protein 95 seen in the prefrontal cortex, dentate gyrus, and CA3 of the hippocampus from susceptible mice, 8 days after a single dose. Again, in a similar manner to ketamine, MGS0039 significantly attenuated the reduction of spine density in the prelimbic regions of the medial prefrontal cortex, dentate gyrus, and CA3 of the hippocampus, but not infralimbic regions of the medial prefrontal cortex and CA1, in susceptible mice 8 days after a single dose. In contrast, neither drug elicited an effect on altered brain-derived neurotrophic factor-TrkB signaling, GluA1, and postsynaptic density protein 95 levels and did not increase spine density observed in the nucleus accumbens of susceptible mice. Conclusions: Similar to ketamine, MGS0039 shows rapid and sustained antidepressant effects in the social defeat stress model. Long-lasting synaptogenesis in the prelimbic regions of medial prefrontal cortex, dentate gyrus, and CA3 might be implicated in this sustained antidepressant effect.
Assuntos
Comportamento Animal/efeitos dos fármacos , Compostos Bicíclicos com Pontes/farmacologia , Ácidos Dicarboxílicos/farmacologia , Ketamina/farmacologia , Animais , Antidepressivos/farmacologia , Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Espinhas Dendríticas/efeitos dos fármacos , Proteína 4 Homóloga a Disks-Large/metabolismo , Preferências Alimentares/efeitos dos fármacos , Resposta de Imobilidade Tônica/efeitos dos fármacos , Masculino , Camundongos , Proteínas Quinases/metabolismo , Receptores de Glutamato Metabotrópico/metabolismoRESUMO
Brain-derived neurotrophic factor (BDNF) and its high-affinity receptor, tropomyosin receptor kinase B (TrkB) signaling plays a key role in the brain neurodevelopment. The exposure of pregnant mice to polyinosinic-polycytidylic acid [poly(I:C)] causes cognitive deficits in adult offspring. Supplementation with a TrkB agonist, 7,8-dihydroxyflavone, in poly(I:C)-treated pregnant mice from pregnancy to weaning could prevent the onset of cognitive deficits and reduced BDNF-TrkB signaling in the prefrontal cortex of their adult offspring. These findings suggest that supplementation with a TrkB agonist in pregnant women with an ultra-high risk of psychosis may reduce the development of psychosis in their offspring.
Assuntos
Transtornos Cognitivos/etiologia , Transtornos Cognitivos/prevenção & controle , Flavonas/administração & dosagem , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Análise de Variância , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Transtornos Cognitivos/patologia , Modelos Animais de Doenças , Esquema de Medicação , Feminino , Indutores de Interferon/toxicidade , Locomoção/efeitos dos fármacos , Masculino , Camundongos , Poli I-C/toxicidade , Gravidez , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/tratamento farmacológico , Receptor trkB/metabolismo , Reconhecimento Psicológico/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacosRESUMO
Using learned helplessness (LH) model of depression, we measured protein expression of brain-derived neurotrophic factor (BDNF) pro-peptide, BDNF precursors (proBDNF and preproBDNF) in the brain regions of LH (susceptible) and non-LH rats (resilience). Expression of preproBDNF, proBDNF and BDNF pro-peptide in the medial prefrontal cortex of LH rats, but not non-LH rats, was significantly higher than control rats, although expression of these proteins in the nucleus accumbens of LH rats was significantly lower than control rats. This study suggests that regional differences in conversion of BDNF precursors into BDNF and BDNF pro-peptide by proteolytic cleavage may contribute to stress resilience.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Encéfalo/metabolismo , Depressão/patologia , Regulação da Expressão Gênica/fisiologia , Desamparo Aprendido , Precursores de Proteínas/metabolismo , Análise de Variância , Animais , Depressão/etiologia , Modelos Animais de Doenças , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND: In order to shed light on the regenerative mechanism of mesenchymal stem cells (MSCs) in vivo, the bio-distribution profile of implanted cells using a stable and long-term tracking method is needed. We herein investigated the bio-distribution of human placental deciduas basalis derived MSCs (termed as PDB-MSCs) in nude mice after intravenous injection by carbon radioisotope labeling thymidine ((14)C-TdR), which is able to incorporate into new DNA strands during cell replication. RESULTS: The proliferation rate and radioactive emission of human PDB-MSCs after labeled with different concentrations of (14)C-TdR were measured. PDB-MSCs labeled with 1 µCi possessed high radioactivity, and the biological characteristics (i.e. morphology, colony forming ability, differentiation capabilities, karyotype and cell cycle) showed no significant changes after labeling. Thus, 1 µCi was the optimal concentration in this experimental design. In nude mice, 1 × 10(6) (14)C-TdR-labeled PDB-MSCs were injected intravenously and the organs were collected at days 1, 2, 3, 5, 30 and 180 after injection, respectively. Radiolabeled PDB-MSCs were found mainly in the lung, liver, spleen, stomach and left femur of the recipient nude mice at the whole observation period. CONCLUSIONS: This work provided solid evidence that (14)C-TdR labeling did not alter the biological characteristics of human placental MSCs, and that this labeling method has potential to decrease the signal from non-infused or dead cells for cell tracking. Therefore, this labeling technique can be utilized to quantify the infused cells after long-term follow-up in pre-clinical studies.
Assuntos
Radioisótopos de Carbono/farmacocinética , Rastreamento de Células/métodos , Células-Tronco Mesenquimais/química , Células-Tronco Mesenquimais/citologia , Placenta/citologia , Timidina/farmacocinética , Animais , Radioisótopos de Carbono/química , Feminino , Humanos , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Nus , Gravidez , Timidina/química , Distribuição TecidualRESUMO
BACKGROUND: In the learned helplessness (LH) paradigm, approximately 35% of rats are resilient to inescapable stress. METHODS: The roles of brain-derived neurotrophic factor (BDNF) and dendritic spine density in the brain regions of LH (susceptible) and non-LH rats (resilient) were examined. Western blot analysis and Golgi staining were performed. RESULTS: BDNF levels in the medial prefrontal cortex, CA3, and dentate gyrus (DG) were significantly lower in the LH group than in the control and non-LH groups, whereas BDNF levels in the nucleus accumbens (NAc) in the LH group but not the non-LH group were significantly higher than those in the control group. Furthermore, spine density in the prelimbic cortex, CA3, and DG was significantly lower in the LH group than in the control and non-LH groups, although spine density in the NAc was significantly higher in the LH group than in the control and non-LH groups. CONCLUSIONS: The results suggest that regional differences in BDNF levels and spine density in rat brain may contribute to resilience to inescapable stress.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Encéfalo/metabolismo , Espinhas Dendríticas/patologia , Desamparo Aprendido , Estresse Psicológico/psicologia , Animais , Comportamento Animal , Western Blotting , Encéfalo/patologia , Região CA3 Hipocampal/metabolismo , Giro Denteado/metabolismo , Masculino , Núcleo Accumbens/metabolismo , Córtex Pré-Frontal/metabolismo , Ratos , Ratos Sprague-Dawley , Coloração pela Prata/métodos , Estresse Psicológico/metabolismo , Estresse Psicológico/patologiaRESUMO
OBJECTIVE: Accumulating evidences suggest that pro-inflammatory cytokines such as interleukin-6 (IL-6) play a role in the pathophysiology of depression. In the learned helplessness (LH) paradigm, ~35% rats are resilient to inescapable stress. METHODS: Levels of IL-6 in the serum and medial prefrontal cortex (mPFC) of LH rats (susceptible) and non-LH rats (resilience) were measured using enzyme-linked immunosorbent assay and western blot analysis, respectively. RESULTS: Serum levels of IL-6 in the LH rats were significantly higher than those of control and non-LH rats. In contrast, tissue levels of IL-6 in the mPFC were not different among three groups. CONCLUSION: The results suggest that peripheral IL-6 may contribute to resilience versus susceptibility to inescapable stress.
Assuntos
Depressão/metabolismo , Desamparo Aprendido , Interleucina-6/metabolismo , Córtex Pré-Frontal/metabolismo , Estresse Psicológico/fisiopatologia , Animais , Anticorpos Monoclonais Humanizados/farmacologia , Depressão/sangue , Depressão/psicologia , Suscetibilidade a Doenças , Ensaio de Imunoadsorção Enzimática/métodos , Interleucina-6/sangue , Masculino , Ratos , Ratos Sprague-Dawley , Estresse Psicológico/metabolismo , Estresse Psicológico/psicologiaRESUMO
Postnatal dexamethasone (DEX) therapy has been used to treat or prevent chronic lung disease after premature births. However, there are many reports of long-term negative neurodevelopmental sequelae following this treatment. In contrast, hydrocortisone (HYD), which has fewer neurodevelopment adverse effects, is used as an alternative for DEX. In this study, we report that neonatal DEX exposure (days 1-3) caused alterations of amino acids affecting N-methyl-d-aspartate (NMDA) receptor neurotransmission in mouse brains. Neonatal DEX, but not HYD, exposure (days 1-3) significantly decreased the GluN2B subunit of NMDA receptor in the hippocampus at juvenile and adult stages. Mice treated with DEX showed cognitive deficits, as well as anxiety and depressive-like behavior at juvenile and adult stages. In contrast, mice treated with HYD (days 1-3) showed no behavioral abnormalities at these stages. In the DEX suppression test, plasma levels of corticosterone in mice exposed neonatally to DEX and HYD were significantly higher at juvenile, but not adult stages. Pretreatment with Ro 63-1908, an antagonist at GluN2B subunit, 30min before each injection of DEX, prevented cognitive deficits, as well as anxiety and depressive-like behavior in juvenile and adult mice. Interestingly, subsequent repeated (days 29-33) administration of Ro 63-1908 or L701324, an antagonist of the glycine modulatory site on the NMDA receptor, significantly suppressed behavioral abnormalities in juvenile and adult mice after neonatal DEX exposure. These results indicate that neonatal DEX, but not HYD, exposure produced behavioral abnormalities in juvenile and adult mice by altering glutamatergic neurotransmission via the NMDA receptor. The NMDA receptor antagonists may prevent or treat these DEX-induced neonatal behavioral abnormalities in later life.
Assuntos
Ansiedade/induzido quimicamente , Transtornos Cognitivos/induzido quimicamente , Depressão/induzido quimicamente , Dexametasona/toxicidade , Receptores de N-Metil-D-Aspartato/metabolismo , Fatores Etários , Animais , Animais Recém-Nascidos , Ansiedade/metabolismo , Química Encefálica , Transtornos Cognitivos/metabolismo , Depressão/metabolismo , Feminino , Lobo Frontal , Hipocampo/metabolismo , Hidrocortisona/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Atividade Motora/efeitos dos fármacosRESUMO
BACKGROUND: Brain-derived neurotrophic factor (BDNF) and its receptor, tropomyosin-related kinase B (TrkB), signaling represent potential therapeutic targets for major depressive disorder. The purpose of this study is to examine whether TrkB ligands show antidepressant effects in an inflammation-induced model of depression. METHODS: In this study, we examined the effects of TrkB agonist 7,8-dihydroxyflavone (7,8-DHF) and TrkB antagonist ANA-12 on depression-like behavior and morphological changes in mice previously exposed to lipopolysaccharide (LPS). Protein levels of BDNF, phospho-TrkB (p-TrkB), and TrkB in the brain regions were also examined. RESULTS: LPS caused a reduction of BDNF in the CA3 and dentate gyrus (DG) of the hippocampus and prefrontal cortex (PFC), whereas LPS increased BDNF in the nucleus accumbens (NAc). Dexamethason suppression tests showed hyperactivity of the hypothalamic-pituitary-adrenal axis in LPS-treated mice. Intraperitoneal (i.p.) administration of 7,8-DHF showed antidepressant effects on LPS-induced depression-like behavior, and i.p. pretreatment with ANA-12 blocked its antidepressant effects. Surprisingly, ANA-12 alone showed antidepressant-like effects on LPS-induced depression-like behavior. Furthermore, bilateral infusion of ANA-12 into the NAc showed antidepressant effects. Moreover, LPS caused a reduction of spine density in the CA3, DG, and PFC, whereas LPS increased spine density in the NAc. Interestingly, 7,8-DHF significantly attenuated LPS-induced reduction of p-TrkB and spine densities in the CA3, DG, and PFC, whereas ANA-12 significantly attenuated LPS-induced increases of p-TrkB and spine density in the NAc. CONCLUSIONS: The results suggest that LPS-induced inflammation may cause depression-like behavior by altering BDNF and spine density in the CA3, DG, PFC, and NAc, which may be involved in the antidepressant effects of 7,8-DHF and ANA-12, respectively.
Assuntos
Antidepressivos/farmacologia , Espinhas Dendríticas/efeitos dos fármacos , Transtorno Depressivo/tratamento farmacológico , Receptor trkB/agonistas , Receptor trkB/antagonistas & inibidores , Animais , Azepinas/farmacologia , Benzamidas/farmacologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Espinhas Dendríticas/fisiologia , Transtorno Depressivo/fisiopatologia , Modelos Animais de Doenças , Flavonas/farmacologia , Hipocampo/efeitos dos fármacos , Hipocampo/fisiopatologia , Lipopolissacarídeos , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos Endogâmicos C57BL , Complexos Multiproteicos/metabolismo , Núcleo Accumbens/efeitos dos fármacos , Núcleo Accumbens/fisiopatologia , Fosforilação/efeitos dos fármacos , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/fisiopatologia , Receptor trkB/metabolismo , Serina-Treonina Quinases TOR/metabolismoRESUMO
BACKGROUND: The development of ketamine-like rapid antidepressants holds promise for enhancing the therapeutic efficacy of depression, but the underlying cellular and molecular mechanisms remain unclear. Implicated in depression regulation, the neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) is investigated here to examine its role in mediating the rapid antidepressant response. METHODS: The onset of antidepressant response was assessed through depression-related behavioral paradigms. The signaling mechanism of PACAP in the hippocampal dentate gyrus (DG) was evaluated by utilizing site-directed gene knockdown, pharmacological interventions, or optogenetic manipulations. Overall, 446 mice were used for behavioral and molecular signaling testing. Mice were divided into control or experimental groups randomly in each experiment, and the experimental manipulations included: chronic paroxetine treatments (4, 9, 14 d) or a single treatment of ketamine; social defeat or lipopolysaccharides-injection induced depression models; different doses of PACAP (0.4, 2, 4 ng/site; microinjected into the hippocampal DG); pharmacological intra-DG interventions (CALM and PACAP6-38); intra-DG viral-mediated PACAP RNAi; and opotogenetics using channelrhodopsins 2 (ChR2) or endoplasmic natronomonas halorhodopsine 3.0 (eNpHR3.0). Behavioral paradigms included novelty suppressed feeding test, tail suspension test, forced swimming test, and sucrose preference test. Western blotting, ELISA, or quantitative real-time PCR (RT-PCR) analysis were used to detect the expressions of proteins/peptides or genes in the hippocampus. RESULTS: Chronic administration of the slow-onset antidepressant paroxetine resulted in an increase in hippocampal PACAP expression, and intra-DG blockade of PACAP attenuated the onset of the antidepressant response. The levels of hippocampal PACAP expression were reduced in both two distinct depression animal models and intra-DG knockdown of PACAP induced depression-like behaviors. Conversely, a single infusion of PACAP into the DG region produced a rapid and sustained antidepressant response in both normal and chronically stressed mice. Optogenetic intra-DG excitation of PACAP-expressing neurons instantly elicited antidepressant responses, while optogenetic inhibition induced depression-like behaviors. The longer optogenetic excitation/inhibition elicited the more sustained antidepressant/depression-like responses. Intra-DG PACAP infusion immediately facilitated the signaling for rapid antidepressant response by inhibiting calcium/calmodulin-dependent protein kinase II (CaMKII)-eukaryotic elongation factor 2 (eEF2) and activating the mammalian target of rapamycin (mTOR). Pre-activation of CaMKII signaling within the DG blunted PACAP-induced rapid antidepressant response as well as eEF2-mTOR-brain-derived neurotrophic factor (BDNF) signaling. Finally, acute ketamine treatment upregulated hippocampal PACAP expression, whereas intra-DG blockade of PACAP signaling attenuated ketamine's rapid antidepressant response. CONCLUSIONS: Activation of hippocampal PACAP signaling induces a rapid antidepressant response through the regulation of CaMKII inhibition-governed eEF2-mTOR-BDNF signaling.
Assuntos
Depressão , Hipocampo , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase , Transdução de Sinais , Animais , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/farmacologia , Camundongos , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Transdução de Sinais/efeitos dos fármacos , Masculino , Depressão/tratamento farmacológico , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Modelos Animais de Doenças , Comportamento Animal/efeitos dos fármacos , Paroxetina/farmacologia , Paroxetina/uso terapêuticoRESUMO
Depression is a prevalent psychiatric disorder with accumulating evidence implicating dysregulation of extracellular adenosine triphosphate (ATP) levels in the medial prefrontal cortex (mPFC). It remains unclear whether facilitating endogenous ATP production and subsequently increasing extracellular ATP level in the mPFC can exert a prophylactic effect against chronic social defeat stress (CSDS)-induced depressive-like behaviors and enhance stress resilience. Here, we found that nicotinamide mononucleotide (NMN) treatment effectively elevated nicotinamide adenine dinucleotide (NAD+) biosynthesis and extracellular ATP levels in the mPFC. Moreover, both the 2-week intraperitoneal (i.p.) injection and 3-week oral gavage of NMN prior to exposure to CSDS effectively prevented the development of depressive-like behavior in mice. These protective effects were accompanied with the preservation of both NAD+ biosynthesis and extracellular ATP level in the mPFC. Furthermore, catalyzing ATP hydrolysis by mPFC injection of the ATPase apyrase negated the prophylactic effects of NMN on CSDS-induced depressive-like behaviors. Prophylactic NMN treatment also prevented the reduction in GABAergic inhibition and the increase in excitability in mPFC neurons projecting to the lateral habenula (LHb). Collectively, these findings demonstrate that the prophylactic effects of NMN on depressive-like behaviors are mediated by preventing extracellular ATP loss in the mPFC, which highlights the potential of NMN supplementation as a novel approach for protecting and preventing stress-induced depression in susceptible individuals.
Assuntos
Trifosfato de Adenosina , Comportamento Animal , Depressão , Camundongos Endogâmicos C57BL , Mononucleotídeo de Nicotinamida , Córtex Pré-Frontal , Estresse Psicológico , Animais , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Masculino , Trifosfato de Adenosina/metabolismo , Mononucleotídeo de Nicotinamida/farmacologia , Depressão/tratamento farmacológico , Depressão/prevenção & controle , Depressão/metabolismo , Estresse Psicológico/complicações , Estresse Psicológico/tratamento farmacológico , Estresse Psicológico/metabolismo , Camundongos , Comportamento Animal/efeitos dos fármacos , Derrota Social , NAD/metabolismo , Modelos Animais de DoençasRESUMO
Parkinson's disease (PD) is the second most common neurodegenerative disorder characterized by the accumulation of α-synuclein (α-syn) aggregates called Lewy bodies leading to the gradual loss of dopaminergic (DA) neurons in the substantia nigra. Although α-syn expression can be attenuated by antisense oligonucleotides (ASOs) and heteroduplex oligonucleotide (HDO) by intracerebroventricular (ICV) injection, the challenge to peripheral targeted delivery of oligonucleotide safely and effectively into DA neurons remains unresolved. Here, we designed a new DNA/DNA double-stranded (complementary DNA, coDNA) molecule with cholesterol conjugation (Chol-HDO (coDNA)) based on an α-syn-ASO sequence and evaluated its silence efficiency. Further, Chol-HDO@LMNPs, Chol-HDO-loaded, cerebrovascular endothelial cell membrane with DSPE-PEG2000-levodopa modification (L-DOPA-CECm)-coated nanoparticles (NPs), were developed for the targeted treatment of PD by tail intravenous injection. CECm facilitated the blood-brain barrier (BBB) penetration of NPs, together with cholesterol escaped from reticuloendothelial system uptake, as well as L-DOPA was decarboxylated into dopamine which promoted the NPs toward the PD site for DA neuron regeneration. The behavioral tests demonstrated that the nanodecoys improved the efficacy of HDO on PD mice. These findings provide insights into the development of biomimetic nanodecoys loading HDO for precise therapy of PD. STATEMENT OF SIGNIFICANCE: The accumulation of α-synuclein (α-syn) aggregates is a hallmark of PD. Our previous study designed a specific antisense oligonucleotide (ASO) targeting human SNCA, but the traumatic intracerebroventricular (ICV) is not conducive to clinical application. Here, we further optimize the ASO by creating a DNA/DNA double-stranded molecule with cholesterol-conjugated, named Chol-HDO (coDNA), and develop a DA-targeted biomimetic nanodecoy Chol-HDO@LMNPs by engineering cerebrovascular endothelial cells membranes (CECm) with DSPE-PEG2000 and L-DOPA. The in vivo results demonstrated that tail vein injection of Chol-HDO@LMNPs could target DA neurons in the brain and ameliorate motor deficits in a PD mouse model. This investigation provides a promising peripheral delivery platform of L-DOPA-CECm nanodecoy loaded with a new Chol-HDO (coDNA) targeting DA neurons in PD therapy.
Assuntos
Doença de Parkinson , Camundongos , Humanos , Animais , Doença de Parkinson/genética , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo , Neurônios Dopaminérgicos/metabolismo , Levodopa , Oligonucleotídeos/farmacologia , Oligonucleotídeos/genética , Oligonucleotídeos/metabolismo , Biomimética , Células Endoteliais/metabolismo , DNA/metabolismoRESUMO
Parkinson's disease (PD) is characterized by the formation of Lewy bodies (LBs) in the brain. These LBs are primarily composed of α-Synuclein (α-Syn), which has aggregated. A recent report proposes that CCAAT/enhancer-binding proteins ß (C/EBPß) may act as an age-dependent transcription factor for α-Syn, thereby initiating PD pathologies by regulating its transcription. Potential therapeutic approaches to address PD could involve targeting the regulation of α-Syn by C/EBPß. This study has revealed that Nrf2, also known as nuclear factor (erythroid-derived 2)-like 2 (NFE2L2), suppresses the transcription of C/EBPß in SH-SY5Y cells when treated with MPP+ . To activate Nrf2, sulforaphane, an Nrf2 activator, was administered. Additionally, C/EBPß was silenced using C/EBPß-DNA/RNA heteroduplex oligonucleotide (HDO). Both approaches successfully reduced abnormal α-Syn expression in primary neurons treated with MPP+ . Furthermore, sustained activation of Nrf2 via its activator or inhibition of C/EBPß using C/EBPß-HDO resulted in a reduction of aberrant α-Syn expression, thus leading to an improvement in the degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc) in mouse models induced by 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP) and those treated with preformed fibrils (PFFs). The data presented in this study illustrate that the activation of Nrf2 may provide a potential therapeutic strategy for PD by inhibiting the abnormal C/EBPß/α-Syn signaling pathway.