RESUMO
Congenital Myasthenic Syndromes (CMS) are a set of genetic diseases that affect the neuromuscular transmission causing muscular weakness. The standard pharmacological treatment aims at ameliorating the myasthenic symptom by acetylcholinesterase inhibitors. Most patients respond well in the short and medium term, however, over time the beneficial effects rapidly fade, and the efficacy of the treatment diminishes. Increasing evidence shows that ß2-adrenergic agonists can be a suitable choice for the treatment of neuromuscular disorders, including CMS, as they promote beneficial effects in the neuromuscular system. The exact mechanism on which they rely is not completely understood, although patients and animal models respond well to the treatment, especially over extended periods. Here, we report the use of the long-lasting specific ß2-adrenergic agonist formoterol in a myasthenic mouse model (mnVAChT-KD), featuring deletion of VAChT (Vesicular Acetylcholine Transporter) specifically in the α-motoneurons. Our findings demonstrate that formoterol treatment (300 µg/kg/day; sc) for 30 days increased the neuromuscular junction area, induced skeletal muscle hypertrophy and altered fibre type composition in myasthenic mice. Interestingly, ß2-adrenergic agonists have shown efficacy even in the absence of ACh (acetylcholine). Our data provide important evidence supporting the potential of ß2-adrenergic agonists in treating neuromuscular disorders of pre-synaptic origin and characterized by disruptions in nerve-muscle communication, through a direct and beneficial action within the motor unit.
Assuntos
Agonistas de Receptores Adrenérgicos beta 2 , Modelos Animais de Doenças , Fumarato de Formoterol , Síndromes Miastênicas Congênitas , Junção Neuromuscular , Proteínas Vesiculares de Transporte de Acetilcolina , Animais , Síndromes Miastênicas Congênitas/tratamento farmacológico , Síndromes Miastênicas Congênitas/genética , Fumarato de Formoterol/farmacologia , Fumarato de Formoterol/uso terapêutico , Agonistas de Receptores Adrenérgicos beta 2/farmacologia , Junção Neuromuscular/efeitos dos fármacos , Camundongos , Proteínas Vesiculares de Transporte de Acetilcolina/metabolismo , Proteínas Vesiculares de Transporte de Acetilcolina/genética , Camundongos Endogâmicos C57BL , MasculinoRESUMO
Background: The integration of diagnostic methods holds promise for advancing the surveillance of malaria transmission in both endemic and non-endemic regions. Serological assays emerge as valuable tools to identify and delimit malaria transmission, serving as a complementary method to rapid diagnostic tests (RDT) and thick smear microscopy. Here, we evaluate the potential of antibodies directed against peptides encompassing the entire amino acid sequence of the PvMSP-1 Sal-I strain as viable serological biomarkers for P. vivax exposure. Methods: We screened peptides encompassing the complete amino acid sequence of the Plasmodium vivax Merozoite Surface Protein 1 (PvMSP-1) Sal-I strain as potential biomarkers for P. vivax exposure. Here, immunodominant peptides specifically recognized by antibodies from individuals infected with P. vivax were identified using the SPOT-synthesis technique followed by immunoblotting. Two 15-mer peptides were selected based on their higher and specific reactivity in immunoblotting assays. Subsequently, peptides p70 and p314 were synthesized in soluble form using SPPS (Solid Phase Peptide Synthesis) and tested by ELISA (IgG, and subclasses). Results: This study unveils the presence of IgG antibodies against the peptide p314 in most P. vivax-infected individuals from the Brazilian Amazon region. In silico B-cell epitope prediction further supports the utilization of p314 as a potential biomarker for evaluating malaria transmission, strengthened by its amino acid sequence being part of a conserved block of PvMSP-1. Indeed, compared to patients infected with P. falciparum and uninfected individuals never exposed to malaria, P. vivax-infected patients have a notably higher recognition of p314 by IgG1 and IgG3.
Assuntos
Anticorpos Antiprotozoários , Biomarcadores , Malária Vivax , Proteína 1 de Superfície de Merozoito , Plasmodium vivax , Humanos , Malária Vivax/imunologia , Malária Vivax/sangue , Malária Vivax/parasitologia , Malária Vivax/transmissão , Malária Vivax/diagnóstico , Proteína 1 de Superfície de Merozoito/imunologia , Plasmodium vivax/imunologia , Biomarcadores/sangue , Anticorpos Antiprotozoários/imunologia , Anticorpos Antiprotozoários/sangue , Imunoglobulina G/imunologia , Imunoglobulina G/sangue , Adulto , Feminino , Masculino , Pessoa de Meia-Idade , Peptídeos/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Adulto Jovem , Adolescente , Sequência de AminoácidosRESUMO
INTRODUCTION: Inflammasome complexes, especially NLRP3, have gained great attention as a potential therapeutic target in mood disorders. NLRP3 triggers a caspase 1-dependent release of the inflammatory cytokines IL-1ß and IL-18, and seems to interact with purinergic and kynurenine pathways, all of which are implicated in mood disorders development and progression. AREAS COVERED: Emerging evidence supports NLRP3 inflammasome as a promising pharmacological target for mood disorders. We discussed the available evidence from animal models and human studies and provided a reflection on drawbacks and perspectives for this novel target. EXPERT OPINION: Several studies have supported the involvement of NLRP3 inflammasome in MDD. However, most of the evidence comes from animal models. The role of NLRP3 inflammasome in BD as well as its anti-manic properties is not very clear and requires further exploration. There is evidence of anti-manic effects of P2×R7 antagonists associated with reduction in the brain levels of IL-1ß and TNF-α in a murine model of mania. The involvement of other NLRP3 inflammasome expressing cells besides microglia, like astrocytes, and of other inflammasome complexes in mood disorders also deserves further investigation. Preclinical and clinical characterization of NLRP3 and other inflammasomes in mood disorders is needed before considering translational approaches, including clinical trials.
Assuntos
Modelos Animais de Doenças , Inflamassomos , Terapia de Alvo Molecular , Transtornos do Humor , Proteína 3 que Contém Domínio de Pirina da Família NLR , Animais , Humanos , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Transtornos do Humor/tratamento farmacológico , Transtornos do Humor/fisiopatologia , Camundongos , Transtorno Bipolar/tratamento farmacológico , Transtorno Bipolar/fisiopatologia , Antagonistas do Receptor Purinérgico P2X/farmacologia , Antagonistas do Receptor Purinérgico P2X/administração & dosagem , Transtorno Depressivo Maior/tratamento farmacológico , Transtorno Depressivo Maior/fisiopatologiaRESUMO
Recent evidence has supported a pathogenic role for neuroinflammation in Parkinson's disease (PD). Inflammatory response has been associated with symptoms and subtypes of PD. However, it is unclear whether immune changes are involved in the initial pathogenesis of PD, leading to the non-motor symptoms (NMS) observed in its prodromal stage. The current study aimed to characterize the behavioral and cognitive changes in a toxin-induced model of prodromal PD-like syndrome. We also sought to investigate the role of neuroinflammation in prodromal PD-related NMS. Male mice were subjected to bilateral intranasal infusion with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or saline (control group), followed by comprehensive behavioral, pathological and neurochemical analysis. Intranasal MPTP infusion was able to cause the loss of dopaminergic neurons in the substantia nigra (SN). In parallel, it induced impairment in olfactory discrimination and social memory consolidation, compulsive and anxiety-like behaviors, but did not influence motor performance. Iba-1 and GFAP expressions were increased in the SN, suggesting an activated state of microglia and astrocytes. Consistent with this, MPTP mice had increased levels of IL-10 and IL-17A, and decreased levels of BDNF and TrkA mRNA in the SN. The striatum showed increased IL-17A, BDNF, and NFG levels compared to control mice. In conclusion, neuroinflammation may play an important role in the early stage of experimental PD-like syndrome, leading to cognitive and behavioral changes. Our results also indicate that intranasal administration of MPTP may represent a valuable mouse model for prodromal PD.
Assuntos
Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Sintomas Prodrômicos , Substância Negra , Animais , Masculino , Substância Negra/metabolismo , Substância Negra/patologia , Substância Negra/efeitos dos fármacos , Neurônios Dopaminérgicos/patologia , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/efeitos dos fármacos , Doenças Neuroinflamatórias/patologia , Corpo Estriado/metabolismo , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/patologia , Camundongos , Microglia/metabolismo , Microglia/patologia , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Ansiedade/etiologia , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/farmacologiaRESUMO
CXCL12 is a key chemokine implicated in neuroinflammation, particularly during Zika virus (ZIKV) infection. Specifically, CXCL12 is upregulated in circulating cells of ZIKV infected patients. Here, we developed a lipid nanoparticle (LNP) to deliver siRNA in vivo to assess the impact of CXCL12 silencing in the context of ZIKV infection. The biodistribution of the LNP was assessed in vivo after intravenous injection using fluorescently tagged siRNA. Next, we investigated the ability of the developed LNP to silence CXCL12 in vivo and assessed the resulting effects in a murine model of ZIKV infection. The LNP encapsulating siRNA significantly inhibited CXCL12 levels in the spleen and induced microglial activation in the brain during ZIKV infection. This activation was evidenced by the enhanced expression of iNOS, TNF-α, and CD206 within microglial cells. Moreover, T cell subsets exhibited reduced secretion of IFN-É£ and IL-17 following LNP treatment. Despite no observable alteration in viral load, CXCL12 silencing led to a significant reduction in type-I interferon production compared to both ZIKV-infected and uninfected groups. Furthermore, we found grip strength deficits in the group treated with siRNA-LNP compared to the other groups. Our data suggest a correlation between the upregulated pro-inflammatory cytokines and the observed decrease in strength. Collectively, our results provide evidence that CXCL12 silencing exerts a regulatory influence on the immune response in the brain during ZIKV infection. In addition, the modulation of T-cell activation following CXCL12 silencing provides valuable insights into potential protective mechanisms against ZIKV, offering novel perspectives for combating this infection.
Assuntos
Infecção por Zika virus , Zika virus , Humanos , Camundongos , Animais , RNA Interferente Pequeno , Distribuição Tecidual , Encéfalo , Imunidade , Quimiocina CXCL12/genéticaRESUMO
The present study employed a randomized crossover design to investigate the effect of strength-training exercise at varying intensities on acute changes in plasma brain-derived neurotrophic factor (BDNF) levels. Fourteen trained male subjects (41.0±5.8 years old) were enrolled in the current study. The strength-training protocol included bench press, leg press, and lat pull-down exercises. Participants performed four sets with repetition failure at 60% or 80% of their one-repetition maximum (1RM), with a two-minute rest period. The order of intensity was randomized among volunteers. Blood samples were collected before, immediately after, and one hour after each exercise protocol. A time-point comparison revealed that a single session of strength training at 60% of 1RM increased lactate plasma concentrations from 1.2 to 16 mmol/L (p<0.0001). However, no significant changes were observed in the plasma BDNF concentration. Conversely, the training session at 80% of 1RM increased lactate concentrations from 1.3 to 14 mmol/L (p<0.0001) and BDNF concentrations from 461 to 1730 pg/ml (p=0.035) one hour after the session's conclusion. These findings support the hypothesis that a single strength-training session at 80% 1RM can significantly enhance circulating levels of BDNF.
Assuntos
Treinamento Resistido , Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Fator Neurotrófico Derivado do Encéfalo , Exercício Físico , Ácido Láctico , Força Muscular , Músculo Esquelético , Treinamento Resistido/métodos , DescansoRESUMO
BACKGROUND: Neuropsychiatric disorders, such as mood disorders, schizophrenia, and Alzheimer's disease (AD) and related dementias, are associated to significant morbidity and mortality worldwide. The pathophysiological mechanisms of neuropsychiatric disorders remain to be fully elucidated, which has hampered the development of effective therapies. The Renin Angiotensin System (RAS) is classically viewed as a key regulator of cardiovascular and renal homeostasis. The discovery that RAS components are expressed in the brain pointed out a potential role for this system in central nervous system (CNS) pathologies. The understanding of RAS involvement in the pathogenesis of neuropsychiatric disorders may contribute to identifying novel therapeutic targets. AIMS: We aim to report current experimental and clinical evidence on the role of RAS in physiology and pathophysiology of mood disorders, schizophrenia, AD and related dementias. We also aim to discuss bottlenecks and future perspectives that can foster the development of new related therapeutic strategies. CONCLUSION: The available evidence supports positive therapeutic effects for neuropsychiatric disorders with the inhibition/antagonism of the ACE/Ang II/AT1 receptor axis or the activation of the ACE2/Ang-(1-7)/Mas receptor axis. Most of this evidence comes from pre-clinical studies and clinical studies lag much behind, hampering a potential translation into clinical practice.
Assuntos
Doença de Alzheimer , Sistema Renina-Angiotensina , Humanos , Sistema Renina-Angiotensina/fisiologia , Peptidil Dipeptidase A/metabolismo , Peptidil Dipeptidase A/uso terapêutico , Rim/metabolismo , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/uso terapêutico , Doença de Alzheimer/tratamento farmacológico , Sistema Nervoso Central/metabolismoRESUMO
TNF-α is essential for induction and maintenance of inflammatory responses and its dysregulation is associated with susceptibility to various pathogens that infect the central nervous system. Activation of both microglia and astrocytes leads to TNF-α production, which in turn triggers further activation of these cells. Astrocytes have been implicated in the pathophysiology of a wide range of neurodegenerative diseases with either harmful or protective roles, as these cells are capable of secreting several inflammatory factors and also promote synapse elimination and remodeling. These responses are possible because they sense their surroundings via several receptors, including the metabotropic glutamate receptor 5 (mGluR5). Under neuroinflammatory conditions, mGluR5 activation in astrocytes can be neuroprotective or have the opposite effect. In the current study, we investigated the role of mGluR5 in hiPSC-derived astrocytes subjected to pro-inflammatory stimulation by recombinant TNF-α (rTNF-α). Our results show that mGluR5 blockade by CTEP decreases the secreted levels of pro-inflammatory cytokines (IL-6 and IL-8) following short rTNF-α stimulation, although this effect subsides with time. Additionally, CTEP enhances synaptoneurosome phagocytosis by astrocytes in both non-stimulated and rTNF-α-stimulated conditions, indicating that mGluR5 blockade alone is enough to drive synaptic material engulfment. Finally, mGluR5 antagonism as well as rTNF-α stimulation augment the expression of the reactivity marker SERPINA3 and reduces the expression of synaptogenic molecules. Altogether, these data suggest a complex role for mGluR5 in human astrocytes, since its blockade may have beneficial and detrimental effects under inflammatory conditions.
Assuntos
Astrócitos , Células-Tronco Pluripotentes Induzidas , Fagocitose , Receptor de Glutamato Metabotrópico 5 , Humanos , Astrócitos/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The pathophysiology of post-traumatic brain injury (TBI) behavioral and cognitive changes is not fully understood, especially in its mild presentation. We designed a weight drop TBI model in mice to investigate the role of neuroinflammation in behavioral and cognitive sequelae following mild TBI. C57BL/6 mice displayed depressive-like behavior at 72 h after mild TBI compared with controls, as indicated by a decrease in the latency to first immobility and climbing time in the forced swim test. Additionally, anxiety-like behavior and hippocampal-associated spatial learning and memory impairment were found in the elevated plus maze and in the Barnes maze, respectively. Levels of a set of inflammatory mediators and neurotrophic factors were analyzed at 6 h, 24 h, 72 h, and 30 days after injury in ipsilateral and contralateral hemispheres of the prefrontal cortex and hippocampus. Principal components analysis revealed two principal components (PC), which represented 59.1% of data variability. PC1 (cytokines and chemokines) expression varied between both hemispheres, while PC2 (neurotrophic factors) expression varied only across the investigated brain areas. Our model reproduces mild TBI-associated clinical signs and pathological features and might be a valuable tool to broaden the knowledge regarding mild TBI pathophysiology as well as to test potential therapeutic targets.
Assuntos
Concussão Encefálica , Lesões Encefálicas Traumáticas , Camundongos , Animais , Concussão Encefálica/complicações , Camundongos Endogâmicos C57BL , Encéfalo/patologia , Lesões Encefálicas Traumáticas/complicações , Fatores de Crescimento Neural , Cognição , Aprendizagem em Labirinto/fisiologia , Modelos Animais de DoençasRESUMO
Artepillin C is the most studied compound in Brazilian Green Propolis and, along with its acetylated derivative, displays neurotrophic activity on PC12â cells. Specific inhibitors of the trkA receptor (K252a), PI3K/Akt (LY294002), and MAPK/ERK (U0126) signaling pathways were used to investigate the neurotrophic mechanism. The expression of proteins involved in axonal and synaptic plasticity (GAP-43 and Synapsinâ I) was assessed by western blotting. Additionally, physicochemical properties, pharmacokinetics, and drug-likeness were evaluated by the SwissADME web tool. Both compounds induced neurite outgrowth by activating the NGF-signaling pathways but through different neuronal proteins. Furthermore, inâ silico analyses showed interesting physicochemical and pharmacokinetic properties of these compounds. Therefore, these compounds could play an important role in axonal and synaptic plasticity and should be further investigated.