RESUMO
Monocyte aberrations have been increasingly recognized as contributors to renal damage in systemic lupus erythematosus (SLE), however, recognition of the underlying mechanisms and modulating strategies is at an early stage. Our studies have demonstrated that brain-derived neurotrophic factor precursor (proBDNF) drives the progress of SLE by perturbing antibody-secreting B cells, and proBDNF facilitates pro-inflammatory responses in monocytes. By utilizing peripheral blood from patients with SLE, GEO database and spontaneous MRL/lpr lupus mice, we demonstrated in the present study that CX3CR1+ patrolling monocytes (PMo) numbers were decreased in SLE. ProBDNF was specifically expressed in CX3CR1+ PMo and was closely correlated with disease activity and the degree of renal injury in SLE patients. In MRL/lpr mice, elevated proBDNF was found in circulating PMo and the kidney, and blockade of proBDNF restored the balance of circulating and kidney-infiltrating PMo. This blockade also led to the reversal of pro-inflammatory responses in monocytes and a noticeable improvement in renal damage in lupus mice. Overall, the results indicate that the upregulation of proBDNF in PMo plays a crucial role in their infiltration into the kidney, thereby contributing to nephritis in SLE. Targeting of proBDNF offers a potential therapeutic role in modulating monocyte-driven renal damage in SLE.
Assuntos
Lúpus Eritematoso Sistêmico , Nefrite Lúpica , Animais , Humanos , Camundongos , Rim , Camundongos Endogâmicos MRL lpr , Monócitos , Regulação para Cima , Precursores de ProteínasRESUMO
Patients suffering from sepsis-induced acute lung injury (ALI) exhibit a high mortality rate, and their prognosis is closely associated with infiltration of neutrophils into the lungs. In this study, we found a significant elevation of CD64+ neutrophils, which highly expressed p75 neurotrophin receptor (p75NTR) in peripheral blood of mice and patients with sepsis-induced ALI. p75NTR+CD64+ neutrophils were also abundantly expressed in the lung of ALI mice induced by lipopolysaccharide. Conditional knock-out of the myeloid lineage's p75NTR gene improved the survival rates, attenuated lung tissue inflammation, reduced neutrophil infiltration and enhanced the phagocytic functions of CD64+ neutrophils. In vitro, p75NTR+CD64+ neutrophils exhibited an upregulation and compromised phagocytic activity in blood samples of ALI patients. Blocking p75NTR activity by soluble p75NTR extracellular domain peptide (p75ECD-Fc) boosted CD64+ neutrophils phagocytic activity and reduced inflammatory cytokine production via regulation of the NF-κB activity. The findings strongly indicate that p75NTR+CD64+ neutrophils are a novel pathogenic neutrophil subpopulation promoting sepsis-induced ALI.
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Lesão Pulmonar Aguda , Camundongos Endogâmicos C57BL , Neutrófilos , Fagocitose , Receptores de IgG , Receptores de Fator de Crescimento Neural , Sepse , Animais , Lesão Pulmonar Aguda/imunologia , Lesão Pulmonar Aguda/etiologia , Neutrófilos/imunologia , Neutrófilos/metabolismo , Sepse/imunologia , Sepse/complicações , Humanos , Receptores de IgG/metabolismo , Receptores de IgG/genética , Receptores de IgG/imunologia , Camundongos , Masculino , Fagocitose/imunologia , Receptores de Fator de Crescimento Neural/metabolismo , Receptores de Fator de Crescimento Neural/genética , Receptores de Fator de Crescimento Neural/imunologia , Camundongos Knockout , Lipopolissacarídeos , Citocinas/metabolismo , Citocinas/imunologia , Pulmão/imunologia , Pulmão/patologia , Feminino , NF-kappa B/metabolismo , NF-kappa B/imunologia , Proteínas do Tecido NervosoRESUMO
Multiple sclerosis (MS) is a chronic autoimmune disorder characterized by the infiltration of inflammatory cells and demyelination of nerves. Mitochondrial dysfunction has been implicated in the pathogenesis of MS, as studies have shown abnormalities in mitochondrial activities, metabolism, mitochondrial DNA (mtDNA) levels, and mitochondrial morphology in immune cells of individuals with MS. The presence of mitochondrial dysfunctions in immune cells contributes to immunological dysregulation and neurodegeneration in MS. This review provided a comprehensive overview of mitochondrial dysfunction in immune cells associated with MS, focusing on the potential consequences of mitochondrial metabolic reprogramming on immune function. Current challenges and future directions in the field of immune-metabolic MS and its potential as a therapeutic target were also discussed.
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Doenças Mitocondriais , Esclerose Múltipla , Humanos , Esclerose Múltipla/patologia , Mitocôndrias/patologia , DNA MitocondrialRESUMO
Brain-derived neurotrophic factor precursor (proBDNF) has been reported to strengthen the dysfunction of monocytes/macrophages in animal studies. However, it is still unknown the roles of proBDNF in the dysfunction of monocytes in the inflammatory diseases in humans. In the present study, we showed that proBDNF and pan neurotrophic receptor p75 were significantly upregulated in monocytes from healthy donors (HD) after lipopolysaccharide treatment. Exogenous proBDNF treatment upregulated CD40 and proinflammatory cytokines expression in monocytes including interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α. In Stanford type-A acute aortic dissection (AAD) patients, proBDNF was upregulated in CD14+ CD163+ CX3CR1+ M2- but not CD14+ CD68+ CCR2+ M1-like monocytes. In addition, sera from AAD patients activated gene expression of proinflammatory cytokines in cultured PBMCs from HD, which was attenuated by proBDNF monoclonal antibody (Ab-proB) treatment. These findings suggested that upregulation of proBDNF in M2-like monocytes may contribute to the proinflammatory response in the AAD.
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Fator Neurotrófico Derivado do Encéfalo/metabolismo , Citocinas/metabolismo , Macrófagos/metabolismo , Monócitos/metabolismo , Precursores de Proteínas/metabolismo , Adulto , Dissecção Aórtica/metabolismo , Células Cultivadas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fator de Necrose Tumoral alfa/metabolismo , Regulação para CimaRESUMO
BACKGROUND: Sepsis-associated encephalopathy (SAE) increases the mortality of septic patients, but its mechanism remains unclear. The present study aimed to investigate the roles of T lymphocytes, proBDNF, and their interaction in the pathogenesis of SAE. METHODS: Fear conditioning tests were conducted for cognitive assessment in the lipopolysaccharide (LPS, 5 mg kg-1)-induced septic mice. Meninges and peripheral blood were harvested for flow cytometry or qPCR. FTY720 and monoclonal anti-proBDNF antibody (McAb-proB) were used to investigate the effect of lymphocyte depletion and blocking proBDNF on the impaired cognitive functions in the septic mice. RESULTS: In the septic mice, cognitive function was impaired, the percentage of CD4+ T cells were decreased in the meninges (P = 0.0021) and circulation (P = 0.0222), and pro-inflammatory cytokines were upregulated, but the anti-inflammatory cytokines interleukin (IL)-4 (P < 0.0001) and IL-13 (P = 0.0350) were downregulated in the meninges. Lymphocyte depletion by intragastrically treated FTY720 (1 mg kg-1) for 1 week ameliorated LPS-induced learning deficit. In addition, proBDNF was increased in the meningeal (P = 0.0042) and peripheral (P = 0.0090) CD4+ T cells. Intraperitoneal injection of McAb-proB (100 µg) before LPS treatment significantly alleviated cognitive dysfunction, inhibited the downregulation of meningeal (P = 0.0264) and peripheral (P = 0.0080) CD4+ T cells, and normalized the gene expression of cytokines in the meninges. However, intra-cerebroventricular McAb-proB injection (1 µg) did not have such effect. Finally, exogenous proBDNF downregulated the percentage of CD4+ T cells in cultured splenocytes from septic mice (P = 0.0021). CONCLUSION: Upregulated proBDNF in immune system promoted the pathogenesis of SAE through downregulating the circulating CD4+ T cells, limiting its infiltration into the meninges and perturbing the meningeal pro-/anti-inflammatory homeostasis.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/imunologia , Linfócitos T CD4-Positivos/imunologia , Meninges/imunologia , Precursores de Proteínas/imunologia , Encefalopatia Associada a Sepse/imunologia , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Lipopolissacarídeos/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Precursores de Proteínas/metabolismo , Encefalopatia Associada a Sepse/induzido quimicamente , Encefalopatia Associada a Sepse/metabolismoRESUMO
BACKGROUND: In highly complex social settings, an animal's motivational drive to pursue an object depends not only on the intrinsic properties of the object, but also on whether the decision-making animal perceives an object as being the most desirable among others. Mimetic desire refers to a subject's preference for objects already possessed by another subject. To date, there are no appropriate animal models for studying whether mimetic desire is at play in guiding the decision-making process. Furthermore, the neuropharmacological bases of decision-making processes are not well understood. In this study, we used an animal model (rat) to investigate a novel food-foraging paradigm for decision-making, with or without a mimetic desire paradigm. RESULTS: Faced with the choice of foraging in a competitive environment, rats preferred foraging for the desirable object, indicating the rats' ability for decision-making. Notably, treatment with the non-competitive N-methyl-D-aspartate receptor antagonist MK-801, but not with the dopamine D1 or D2 receptor antagonists, SCH23390 and haloperidol, respectively, suppressed the food foraging preference when there was a competing resident rat in the cage. None of these three antagonists affected the food-foraging preference for palatable food. Moreover, MK-801 and SCH23390, but not haloperidol, were able to abolish the desirable environment effect on standard food-foraging activities in complex social settings. CONCLUSIONS: These results highlight the concept that mimetic desire exerts a powerful influence on food-foraging decision-making in rats and, further, illustrate the various roles of the glutamatergic and dopaminergic systems in mediating these processes.
Assuntos
Comportamento Competitivo/fisiologia , Tomada de Decisões/fisiologia , Receptores de Dopamina D1/fisiologia , Receptores de Dopamina D2/fisiologia , Receptores de N-Metil-D-Aspartato/fisiologia , Animais , Benzazepinas/administração & dosagem , Comportamento Competitivo/efeitos dos fármacos , Tomada de Decisões/efeitos dos fármacos , Maleato de Dizocilpina/administração & dosagem , Antagonistas dos Receptores de Dopamina D2/administração & dosagem , Preferências Alimentares/efeitos dos fármacos , Preferências Alimentares/fisiologia , Haloperidol/administração & dosagem , Masculino , Ratos , Ratos Sprague-Dawley , Receptores de Dopamina D1/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/antagonistas & inibidoresRESUMO
MicroRNAs (miRNAs) play vital roles in the post-transcriptional regulation of gene expression. Previous studies have shown that miR-150 is a crucial regulator of B cell proliferation, differentiation, metabolism, and apoptosis. miR-150 regulates the immune homeostasis during the development of obesity and is aberrantly expressed in multiple B-cell-related malignant tumors. Additionally, the altered expression of MIR-150 is a diagnostic biomarker of various autoimmune diseases. Furthermore, exosome-derived miR-150 is considered as prognostic tool in B cell lymphoma, autoimmune diseases and immune-mediated disorders, suggesting miR-150 plays a vital role in disease onset and progression. In this review, we summarized the miR-150-dependent regulation of B cell function in B cell-related immune diseases.
RESUMO
Immune-mediated inflammatory diseases (IMIDs) consist of a common and clinically diverse group of diseases. Despite remarkable progress in the past two decades, no remission is observed in a large number of patients, and no effective treatments have been developed to prevent organ and tissue damage. Brain-derived neurotrophic factor precursor (proBDNF) and receptors, such as p75 neurotrophin receptor (p75NTR) and sortilin, have been proposed to mediate intracellular metabolism and mitochondrial function to regulate the progression of several IMIDs. Here, the regulatory role of proBDNF and its receptors in seven typical IMIDs, including multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus, allergic asthma, type I diabetes, vasculitis, and inflammatory bowel diseases, was investigated.
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Agentes de Imunomodulação , Receptor de Fator de Crescimento Neural , Humanos , Receptor de Fator de Crescimento Neural/metabolismoRESUMO
Background The imbalance of monocyte/macrophage polarization toward the preferential proinflammatory phenotype and a lack of normal inflammation resolution are present in acute myocardial infarction (AMI). Our previous study showed that upregulation of brain-derived neurotrophic factor precursor (proBDNF) in M2-like monocytes may contribute to the proinflammatory response in the Stanford type-A acute aortic dissection. The present study aimed to investigate the role of proBDNF signaling in monocytes/macrophages in the progress of AMI. Methods and Results We observed the upregulation of proBDNF in the proinflammatory monocytes of patients with AMI. The upregulation of proBDNF was also observed in the circulating proinflammatory Ly6Chigh monocytes and cardiac F4/80+CD86+ macrophages 3 days after AMI in a mice model. To neutralize proBDNF, the mice subjected to AMI were injected intraperitoneally with a monoclonal anti-proBDNF antibody. Echocardiography, 2,3,5-triphenyltetrazolium chloride staining, and positron emission tomography/computed tomography results demonstrate that monoclonal anti-proBDNF antibody treatment further impaired cardiac functions, increased infarct size, and exacerbated the proinflammatory state. Moreover, the level of proinflammatory Ly6Chigh in the blood and F4/80+CD86+ in the heart was further increased in monoclonal anti-proBDNF antibody mice. RNA sequencing revealed that matrix metalloprotease-9 protein level was dramatically increased, along with the activated proinflammatory-related cytokines. Matrix metalloprotease-9 inhibitor treatment attenuated the deteriorated effect of monoclonal anti-proBDNF antibody on cardiac function and infarct areas. Conclusions Our study shows that endogenous proBDNF in monocytes/macrophages may exert protective roles in cardiac remodeling after AMI by regulating matrix metalloprotease-9 activity.
Assuntos
Monócitos , Infarto do Miocárdio , Camundongos , Animais , Monócitos/metabolismo , Infarto do Miocárdio/terapia , Macrófagos/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Metaloproteases/metabolismo , Metaloproteases/farmacologia , Camundongos Endogâmicos C57BLRESUMO
Inappropriate expansion of antibody-secreting cells (ASCs) is typical of systemic lupus erythematosus (SLE), but the regulatory signaling of pathogenic ASCs is unclear. The present study shows that brain-derived neurotrophic factor precursor (proBDNF) and its high-affinity pan-75 neurotrophin receptor (p75NTR) are highly expressed in CD19+CD27hiCD38hi ASCs in patients with SLE and in CD19+CD44hiCD138+ ASCs in lupus-like mice. The increased proBDNF+ ASCs were positively correlated with clinical symptoms and higher titers of autoantibodies in SLE. Administration of monoclonal antibodies against proBDNF or specific knockout of p75NTR in CD19+ B cells exerted a therapeutic effect on lupus mice by limiting the proportion of ASCs, reducing the production of autoantibodies and attenuating kidney injury. Blocking the biological function of proBDNF or p75NTR also inhibits ASC differentiation and antibody production in vitro. Together, these findings suggest that proBDNF-p75NTR signaling plays a critical pathogenic role in SLE through promoting ASC dysfunction.
Assuntos
Lúpus Eritematoso Sistêmico , Receptores de Fator de Crescimento Neural , Animais , Antígenos CD19 , Autoanticorpos , Linfócitos B , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Fator de Crescimento Neural/genética , Receptores de Fator de Crescimento Neural/metabolismo , Regulação para CimaRESUMO
Sepsis-associated encephalopathy (SAE) is a risk factor for cognitive and memory dysfunction; however, the mechanism remains unclear. Brain-derived neurotrophic factor (BDNF) was reported to have a positive effect on cognition and emotion regulation, but the study of its precursor, proBDNF, has been limited. This study aimed to elucidate the effects and associated mechanisms of hippocampal proBDNF in a lipopolysaccharide (LPS)-induced SAE mouse model. In this study, we found that the mice exhibited cognitive dysfunction on day 7 after LPS injection. The expression of proBDNF and its receptor, p75 NTR , was also increased in the hippocampus, while the levels of BDNF and its receptor, TrkB, were decreased. A co-localization study showed that proBDNF and p75 NTR were mainly co-localized with neurons. Furthermore, LPS treatment reduced the expression of NeuN, Nissl bodies, GluR4, NR1, NR2A, and NR2B in the hippocampus of SAE mice. Furthermore, an intrahippocampal or intraperitoneal injection of anti-proBDNF antibody was able to ameliorate LPS-induced cognitive dysfunction and restore the expression of NeuN, Nissl bodies, GluR4, NR1, NR2A, NR2B, and PSD95. These results indicated that treatment with brain delivery by an intrahippocampal and systemic injection of mAb-proBDNF may represent a potential therapeutic strategy for treating patients with SAE.
RESUMO
Rationale: Brain-derived neurotrophic factor precursor (proBDNF) is expressed in the central nervous system (CNS) and the immune system. However, the role of proBDNF in the pathogenesis of multiple sclerosis (MS) is unknown. Methods: Peripheral blood and post-mortem brain and spinal cord specimens were obtained from multiple sclerosis patients to analyze proBDNF expression in peripheral lymphocytes and infiltrating immune cells in the lesion site. The proBDNF expression profile was also examined in the experimental autoimmune encephalomyelitis (EAE) mouse model, and polyclonal and monoclonal anti-proBDNF antibodies were used to explore their therapeutic effect in EAE. Finally, the role of proBDNF in the inflammatory immune activity of peripheral blood mononuclear cells (PBMCs) was verified in vitro experiments. Results: High proBDNF expression was detected in the circulating lymphocytes and infiltrated inflammatory cells at the lesion sites of the brain and spinal cord in MS patients. In the EAE mouse model, proBDNF was upregulated in CNS and in circulating and splenic lymphocytes. Systemic but not intracranial administration of anti-proBDNF blocking antibodies attenuated clinical scores, limited demyelination, and inhibited proinflammatory cytokines in EAE mice. Immuno-stimulants treatment increased the proBDNF release and upregulated the expression of p75 neurotrophic receptors (p75NTR) in lymphocytes. The monoclonal antibody against proBDNF inhibited the inflammatory response of PBMCs upon stimulations. Conclusion: The findings suggest that proBDNF from immune cells promotes the immunopathogenesis of MS. Monoclonal Ab-proB may be a promising therapeutic agent for treating MS.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Encéfalo/metabolismo , Encefalomielite Autoimune Experimental/patologia , Leucócitos Mononucleares/metabolismo , Leucócitos/metabolismo , Esclerose Múltipla/patologia , Precursores de Proteínas/metabolismo , Medula Espinal/metabolismo , Animais , Encéfalo/imunologia , Estudos de Casos e Controles , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Humanos , Leucócitos/imunologia , Leucócitos Mononucleares/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Esclerose Múltipla/imunologia , Esclerose Múltipla/metabolismo , Medula Espinal/imunologiaRESUMO
Substantial evidence has revealed that abnormalities in synaptic plasticity play important roles during the process of depression. LASP1 (LIM and SH3 domain protein 1), a member of actin-binding proteins, has been shown to be associated with the regulation of synaptic plasticity. However, the role of LASP1 in the regulation of mood is still unclear. Here, using an unpredictable chronic mild stress (UCMS) paradigm, we found that the mRNA and protein levels of LASP1 were decreased in the hippocampus of stressed mice and that UCMS-induced down-regulation of LASP1 was abolished by chronic administration of fluoxetine. Adenosine-associated virus-mediated hippocampal LASP1 overexpression alleviated the UCMS-induced behavioral results of forced swimming test and sucrose preference test in stressed mice. It also restored the dendritic spine density, elevated the levels of AKT (a serine/threonine protein kinase), phosphorylated-AKT, insulin-like growth factor 2, and postsynaptic density protein 95. These findings suggest that LASP1 alleviates UCMS-provoked behavioral defects, which may be mediated by an enhanced dendritic spine density and more activated AKT-dependent LASP1 signaling, pointing to the antidepressant role of LASP1.
Assuntos
Proteínas do Citoesqueleto/metabolismo , Modelos Animais de Doenças , Hipocampo/metabolismo , Proteínas de Homeodomínio/metabolismo , Proteínas com Domínio LIM/metabolismo , Estresse Psicológico/metabolismo , Animais , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Doença Crônica , Depressão/tratamento farmacológico , Depressão/metabolismo , Depressão/patologia , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estresse Psicológico/tratamento farmacológico , Estresse Psicológico/patologiaRESUMO
Major depressive disorders (MDD) are often comorbid with the gastrointestinal (GI) disorders. Brain-derived neurotrophic factor precursor (proBDNF) has been reported to contribute to the development of depression in mouse models. However, the role of proBDNF in depression-associated GI disorders is still unrevealed. Mice experienced unpredictable chronic mild stress (UCMS) procedure and were then intraperitoneally injected with fluoxetine (20 mg/kg). Open field test (OFT), forced swimming test (FST), and sucrose preference test (SPT) were performed to evaluate the severity of depression. Oral administration of food dye gel and histological staining were performed to assess GI transit and morphological alterations. QPCR was performed to assess the mRNA levels of inflammatory cytokines. Additionally, flow cytometry, immunohistochemistry, and immunofluorescence were performed to examine the expression and cellular localization of proBDNF. It was found that (a) in the peripheral blood, the expression of proBDNF and its receptor pan neurotrophin receptor 75 (p75NTR) in CD11b+ cells in depressive mice was higher than in controls; (b) the GI motility was decreased after the UCMS procedure and partly reversed by fluoxetine treatment; (c) proBDNF/p75NTR was highly expressed in macrophages in the intestinal lamina propria; (d) the upregulated proBDNF/p75NTR and the activated cytokines, including IL (interleukin)-1ß, IL-6, IL-10, and IFN (interferon)-γ, were positively correlated with the depression and GI disorders, and were inhibited by fluoxetine treatment. UCMS procedure upregulated the expression of proBDNF and p75NTR in monocytes/macrophages of peripheral blood and intestinal lamina propria, which may be involved in the pathogenesis of depression-associated GI disorders. Fluoxetine reversed the GI dysfunction, infiltration of macrophages, and upregulation of proBDNF signaling in the depressive mice.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/biossíntese , Transtorno Depressivo Maior/metabolismo , Gastroenteropatias/metabolismo , Macrófagos/metabolismo , Monócitos/metabolismo , Precursores de Proteínas/biossíntese , Animais , Antidepressivos de Segunda Geração/farmacologia , Antidepressivos de Segunda Geração/uso terapêutico , Transtorno Depressivo Maior/tratamento farmacológico , Transtorno Depressivo Maior/psicologia , Modelos Animais de Doenças , Fluoxetina/farmacologia , Fluoxetina/uso terapêutico , Gastroenteropatias/tratamento farmacológico , Gastroenteropatias/psicologia , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/efeitos dos fármacos , Estresse Psicológico/tratamento farmacológico , Estresse Psicológico/metabolismo , Estresse Psicológico/psicologiaRESUMO
Major depression disorder is one of the most common psychiatric disorders that greatly threaten the mental health of a large population worldwide. Previous studies have shown that endoplasmic reticulum (ER) stress plays an important role in the pathophysiology of depression, and current research suggests that brain-derived neurotrophic factor precursor (proBDNF) is involved in the development of depression. However, the relationship between ER and proBDNF in the pathophysiology of depression is not well elucidated. Here, we treated primary hippocampal neurons of mice with corticosterone (CORT) and evaluated the relationship between proBDNF and ERS. Our results showed that CORT induced ERS and upregulated the expression of proBDNF and its receptor, Follistatin-like protein 4 (FSTL4), which contributed to significantly decreased neuronal viability and expression of synaptic-related proteins including NR2A, PSD95, and SYN. Anti-proBDNF neutralization and ISRIB (an inhibitor of the ERS) treatment, respective ly, protected neuronal viabilities and increased the expression of synaptic-related proteins in corticosterone-exposed neurons. ISRIB treatment reduced the expression of proBDNF and FSTL4, whereas anti-proBDNF treatment did not affect ERS markers (Grp78, p-PERK, ATF4) expression. Our study presented evidence that CORT-induced ERS negatively regulated the neuronal viability and the level of synaptic-related protein of primary neurons via the proBDNF/FSTL4 pathway.
Assuntos
Anti-Inflamatórios/farmacologia , Fator Neurotrófico Derivado do Encéfalo/efeitos dos fármacos , Corticosterona/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Hipocampo/citologia , Neurônios/efeitos dos fármacos , Precursores de Proteínas/efeitos dos fármacos , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Transtorno Depressivo Maior , Proteína 4 Homóloga a Disks-Large/efeitos dos fármacos , Proteína 4 Homóloga a Disks-Large/metabolismo , Chaperona BiP do Retículo Endoplasmático , Proteínas Relacionadas à Folistatina/efeitos dos fármacos , Proteínas Relacionadas à Folistatina/metabolismo , Camundongos , Neurônios/metabolismo , Cultura Primária de Células , Precursores de Proteínas/metabolismo , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/metabolismo , Sinaptofisina/metabolismoRESUMO
Dr. Chang-Qi Li should be added as co-author because Fig. 1 originated from him.
RESUMO
The immune status in the lymphatic system, especially mesenteric lymph nodes (MLNs), is critical to regulate the septic shock. Brain-derived neurotrophic factor (BDNF) in the enteric system has been reported to regulate enteric immunity. However, the role of its precursor, proBDNF, in the immune status of MLNs under sepsis condition is still unclear. This study aimed to characterize the expression pattern of proBDNF in MLNs after lipopolysaccharide (LPS) stimulation, and to investigate the association of pathogenesis of sepsis. LPS (20 mg/kg) was intraperitoneally injected to induce sepsis in mice. Survival curve analysis, routine blood tests, and liver and kidney function tests were performed to evaluate the severity of sepsis. QPCR and histological staining were performed to assess the mRNA levels of proinflammatory cytokines and degree of immune-inflammatory response in the MLNs. Furthermore, Western blotting, flow cytometry, and immunofluorescence were performed to examine the key molecules expression of proBDNF signaling. Intraperitoneal LPS injection significantly decreased the number of lymphocytes in blood but increased the number of T lymphocytes in MLNs. Serum alanine transaminase, aspartate transaminase, and blood urea nitrogen levels were increased in LPS-challenged mice compared to control mice. LPS administration upregulated proinflammatory cytokine gene expression and induced histological changes in the MLNs. LPS injection increased BDNF, proBDNF, and its receptor pan neutrophin receptor 75 (p75NTR) expression in MLNs. The increased proBDNF was mainly localized on CD3+ and CD4+ T cells in the medulla of MLNs. LPS-induced sepsis upregulated proBDNF expression in medulla T cells of MLNs. ProBDNF upregulation may be involved in the pathogenesis of septic shock.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Linfonodos/metabolismo , Precursores de Proteínas/metabolismo , Sepse/metabolismo , Animais , Western Blotting , Modelos Animais de Doenças , Citometria de Fluxo , Imunofluorescência , Rim/efeitos dos fármacos , Rim/fisiopatologia , Lipopolissacarídeos/farmacologia , Fígado/efeitos dos fármacos , Fígado/fisiopatologia , Masculino , Mesentério , Camundongos , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase em Tempo Real , Sepse/fisiopatologia , Regulação para CimaRESUMO
Stress plays a crucial role in several psychiatric disorders, including anxiety. However, the underlying mechanisms remain poorly understood. Here, we used acute stress (AS) and chronic restraint stress (CRS) models to develop anxiety-like behavior and investigate the role of miR-150 in the hippocampi of mice. Corticosterone levels as well as glutamate receptors in the hippocampus were evaluated. We found that anxiety-like behavior was induced after either AS or CRS, as determined by the open-field test (OFT) and elevated plus-maze test (EPM). Increased corticosterone levels were observed in the blood of AS and CRS groups, while the expression of miR-150 mRNA in the hippocampus was significantly decreased. The expressions of GluN2A, GluR1, GluR2, and V-Glut2 in the hippocampus were decreased after either AS or CRS. Hippocampal GAD67 expression was increased by AS but not CRS, and GluN2B expression was decreased by CRS but not AS. Adult miR-150 knockout mice showed anxiety-like behavior, as assessed by the OFT and EPM. The expressions of GluN2A, GluN2B, GluR1, and GluR2 were also downregulated, but the expression of V-Glut2 was upregulated in the hippocampi of miR-150 knockout mice compared with wild-type mice. Interestingly, we found that the miR-150 knockout mice showed decreased dendrite lengths, dendrite branchings, and numbers of dendrite spines in the hippocampus compared with wild-type mice. These results suggest that miR-150 may influence the synaptic plasticity of the hippocampus and play a significant role in stress-induced anxiety-like behavior in adult mice.
Assuntos
Ansiedade/etiologia , Ansiedade/metabolismo , MicroRNAs/metabolismo , Estresse Psicológico/complicações , Estresse Psicológico/metabolismo , Sistema X-AG de Transporte de Aminoácidos/metabolismo , Animais , Ansiedade/patologia , Corticosterona/metabolismo , Dendritos/metabolismo , Dendritos/patologia , Regulação da Expressão Gênica , Hipocampo/metabolismo , Hipocampo/patologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , MicroRNAs/genética , RNA Mensageiro/metabolismo , Distribuição Aleatória , Receptores de Glutamato/metabolismo , Restrição Física , Estresse Psicológico/patologiaRESUMO
Stress can influence decision-making in humans from many cognitive perspectives, while the underlying neurobiological mechanism remains incompletely understood. Food-foraging is a rodent behavior involving strategic possessing of nutritional supply in social context; experimental model of this behavior could help explore the effect of stress on decision-making and the brain mechanism thereof. In the present study, the influence of stress on food-foraging behavior was assessed in rats using an open field choosing paradigm wherein food collection (standard food or sweet food) were associated with social competition (with or without a rat in the cage). Acute restraint stress (ARS) was induced by placing the rat in a plastic restrainer for 2 h before food-foraging behavioral tests, with the effect of stress also determined biochemically and immunohistochemically. Restraint stressed rats showed anxiety-like behavior and elevation of serum corticosterone (CORT) and epinephrine (EPI) relative to controls. Both restraint and control animals preferred sugared food. However, the former group tended to forage food from a cage not occupied by a conspecific rat, whereas the control rats preferred to obtain food from the cage with a social competitor. Thus, the total amount of food foraged and eaten are reduced in the restrained rats than in controls. While the restraint animals had normal social interaction with other rats, they displayed enhanced social agonistic behavior. In brain examination, ARS attenuated the increase in immunolabeling and protein levels of c-fos, p-CREB, p-ERK1/2 in the anterior cingulate cortex (ACC) observed in control animals in association with food-foraging. These results indicate that restraint stressed rats tend to forage food by taking the advantage of a less competitive opportunity. Mechanistically, this decision-making alternative appears to be mediated through a neuronal deactivation in the ACC. The current findings provide novel insights into neuronal processing of decision-making behavior under the influence of stress.
Assuntos
Tomada de Decisões/fisiologia , Comportamento Alimentar/fisiologia , Estresse Psicológico/metabolismo , Animais , Ansiedade/psicologia , Comportamento Animal/fisiologia , Corticosterona/sangue , Epinefrina/sangue , Alimentos , Giro do Cíngulo/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Restrição Física/psicologiaRESUMO
Depression and anxiety are two affective disorders that greatly threaten the mental health of a large population worldwide. Previous studies have shown that brain-derived neurotrophic factor precursor (proBDNF) is involved in the development of depression. However, it is still elusive whether proBDNF is involved in anxiety, and if so, which brain regions of proBDNF regulate these two affective disorders. The present study aims to investigate the role of proBDNF in the hippocampus in the development of depression and anxiety. Rat models of an anxiety-like phenotype and depression-like phenotype were established by complete Freund's adjuvant intra-plantar injection and chronic restraint stress, respectively. Both rat models developed anxiety-like behaviors as determined by the open field test and elevated plus maze test. However, only rats with depression-like phenotype displayed the lower sucrose consumption in the sucrose preference test and a longer immobility time in the forced swimming test. Sholl analysis showed that the dendritic arborization of granule cells in the hippocampus was decreased in rats with depression-like phenotype but was not changed in rats with anxiety-like phenotype. In addition, synaptophysin was downregulated in the rats with depression-like phenotype but upregulated in the rats with anxiety-like phenotype. In both models, proBDNF was greatly increased in the hippocampus. Intra-hippocampal injection anti-proBDNF antibody greatly ameliorated the anxiety-like and depressive behaviors in the rats. These findings suggest that despite some behavioral and morphological differences between depression and anxiety, hippocampal proBDNF is a common mediator to regulate these two mental disorders.