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1.
Int J Mol Sci ; 22(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202695

RESUMO

Chrysomycin A (Chr-A), an antibiotic chrysomycin, was discovered in 1955 and is used to treat cancer and tuberculosis. In the present study, the anti-neuroinflammatory effects and possible mechanism of Chr-A in BALB/c mice and in BV2 microglia cells stimulated by lipopolysaccharide (LPS) were investigated. Firstly, the cortex tissues of mice were analyzed by RNA-seq transcriptome to identify differentially expressed genes (DEGs) regulated by Chr-A in LPS-stimulated mice. Inflammatory cytokines and inflammatory proteins were detected by enzyme-linked immunosorbent assay and Western blot. In RNAseq detection, 639 differential up-regulated genes between the control group and LPS model group and 113 differential down-regulated genes between the LPS model group and Chr-A treatment group were found, and 70 overlapping genes were identified as key genes for Chr-A against neuroinflammation. Subsequent GO biological process enrichment analysis showed that the anti-neuroinflammatory effect of Chr-A might be related to the response to cytokine, cellular response to cytokine stimulus, and regulation of immune system process. The significant signaling pathways of KEGG enrichment analysis were mainly involved in TNF signaling pathway, cytokine-cytokine receptor interaction, NF-κB signaling pathway, IL-17 signaling pathway and NOD-like receptor signaling pathway. Our results of in vivo or in vitro experiments showed that the levels of pro-inflammatory factors including NO, IL-6, IL-1ß, IL-17, TNF-α, MCP-1, CXCL12, GM-CSF and COX2 in the LPS-stimulated group were higher than those in the control group, while Chr-A reversed those conditions. Furthermore, the Western blot analysis showed that its anti-neuroinflammation appeared to be related to the down-regulation of NLRP3/cleaved caspase-1 signaling pathway. The current findings provide new insights into the activity and molecular mechanisms of Chr-A for the treatment of neuroinflammation.


Assuntos
Aminoglicosídeos/farmacologia , Caspase 1/metabolismo , Microglia/efeitos dos fármacos , Microglia/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Inflamação Neurogênica/metabolismo , Transdução de Sinais/efeitos dos fármacos , Aminoglicosídeos/química , Animais , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/imunologia , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Lipopolissacarídeos/imunologia , Camundongos , Microglia/imunologia , Estrutura Molecular , Inflamação Neurogênica/etiologia , Proteólise , Transcriptoma
2.
Int J Mol Sci ; 22(12)2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34198710

RESUMO

Microglial activity in the aging neuroimmune system is a central player in aging-related dysfunction. Aging alters microglial function via shifts in protein signaling cascades. These shifts can propagate neurodegenerative pathology. Therapeutics require a multifaceted approach to understand and address the stochastic nature of this process. Polyphenols offer one such means of rectifying age-related decline. Our group used mass spectrometry (MS) analysis to explicate the complex nature of these aging microglial pathways. In our first experiment, we compared primary microglia isolated from young and aged rats and identified 197 significantly differentially expressed proteins between these groups. Then, we performed bioinformatic analysis to explore differences in canonical signaling cascades related to microglial homeostasis and function with age. In a second experiment, we investigated changes to these pathways in aged animals after 30-day dietary supplementation with NT-020, which is a blend of polyphenols. We identified 144 differentially expressed proteins between the NT-020 group and the control diet group via MS analysis. Bioinformatic analysis predicted an NT-020 driven reversal in the upregulation of age-related canonical pathways that control inflammation, cellular metabolism, and proteostasis. Our results highlight salient aspects of microglial aging at the level of protein interactions and demonstrate a potential role of polyphenols as therapeutics for age-associated dysfunction.


Assuntos
Envelhecimento/fisiologia , Suplementos Nutricionais , Microglia/metabolismo , Polifenóis/farmacologia , Transdução de Sinais , Animais , Dieta , Ontologia Genética , Masculino , Microglia/efeitos dos fármacos , Proteoma/metabolismo , Ratos Endogâmicos F344 , Transdução de Sinais/efeitos dos fármacos
3.
Int J Mol Sci ; 22(12)2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34208040

RESUMO

(1) Background: The pro-resolving lipid mediator Resolvin D1 (RvD1) has already shown protective effects in animal models of diabetic retinopathy. This study aimed to investigate the retinal levels of RvD1 in aged (24 months) and younger (3 months) Balb/c mice, along with the activation of macro- and microglia, apoptosis, and neuroinflammation. (2) Methods: Retinas from male and female mice were used for immunohistochemistry, immunofluorescence, transmission electron microscopy, Western blotting, and enzyme-linked immunosorbent assays. (3) Results: Endogenous retinal levels of RvD1 were reduced in aged mice. While RvD1 levels were similar in younger males and females, they were markedly decreased in aged males but less reduced in aged females. Both aged males and females showed a significant increase in retinal microglia activation compared to younger mice, with a more marked reactivity in aged males than in aged females. The same trend was shown by astrocyte activation, neuroinflammation, apoptosis, and nitrosative stress, in line with the microglia and Müller cell hypertrophy evidenced in aged retinas by electron microscopy. (4) Conclusions: Aged mice had sex-related differences in neuroinflammation and apoptosis and low retinal levels of endogenous RvD1.


Assuntos
Envelhecimento/patologia , Ácidos Docosa-Hexaenoicos/farmacologia , Inflamação/patologia , Retina/patologia , Caracteres Sexuais , Animais , Apoptose/efeitos dos fármacos , Biomarcadores/metabolismo , Caspase 3/metabolismo , Células Ependimogliais/efeitos dos fármacos , Células Ependimogliais/metabolismo , Células Ependimogliais/patologia , Células Ependimogliais/ultraestrutura , Feminino , Masculino , Camundongos Endogâmicos BALB C , Microglia/efeitos dos fármacos , Microglia/metabolismo , Microglia/patologia , Microglia/ultraestrutura , NF-kappa B/metabolismo , Retina/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Tirosina/análogos & derivados , Tirosina/metabolismo
4.
Int J Mol Sci ; 22(11)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34206048

RESUMO

Acrylamide is a well characterized neurotoxicant known to cause neuropathy and encephalopathy in humans and experimental animals. To investigate the role of nuclear factor erythroid 2-related factor 2 (Nrf2) in acrylamide-induced neuropathy, male C57Bl/6JJcl adult mice were exposed to acrylamide at 0, 200 or 300 ppm in drinking water and co-administered with subcutaneous injections of sulforaphane, a known activator of the Nrf2 signaling pathway at 0 or 25 mg/kg body weight daily for 4 weeks. Assessments for neurotoxicity, hepatotoxicity, oxidative stress as well as messenger RNA-expression analysis for Nrf2-antioxidant and pro-inflammatory cytokine genes were conducted. Relative to mice exposed only to acrylamide, co-administration of sulforaphane protected against acrylamide-induced neurotoxic effects such as increase in landing foot spread or decrease in density of noradrenergic axons as well as hepatic necrosis and hemorrhage. Moreover, co-administration of sulforaphane enhanced acrylamide-induced mRNA upregulation of Nrf2 and its downstream antioxidant proteins and suppressed acrylamide-induced mRNA upregulation of tumor necrosis factor alpha (TNF-α) and inducible nitric oxide synthase (iNOS) in the cerebral cortex. The results demonstrate that activation of the Nrf2 signaling pathway by co-treatment of sulforaphane provides protection against acrylamide-induced neurotoxicity through suppression of oxidative stress and inflammation. Nrf2 remains an important target for the strategic prevention of acrylamide-induced neurotoxicity.


Assuntos
Inflamação/genética , Isotiocianatos/farmacologia , Fator 2 Relacionado a NF-E2/genética , Síndromes Neurotóxicas/genética , Sulfóxidos/farmacologia , Acrilamida/toxicidade , Animais , Modelos Animais de Doenças , Humanos , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Inflamação/patologia , Camundongos , Microglia/metabolismo , Microglia/patologia , NF-kappa B/genética , Síndromes Neurotóxicas/tratamento farmacológico , Síndromes Neurotóxicas/etiologia , Síndromes Neurotóxicas/patologia , Óxido Nítrico Sintase Tipo II/genética , Estresse Oxidativo/genética , Transdução de Sinais/efeitos dos fármacos
5.
Int J Mol Sci ; 22(13)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206505

RESUMO

Myosins are a remarkable superfamily of actin-based motor proteins that use the energy derived from ATP hydrolysis to translocate actin filaments and to produce force. Myosins are abundant in different types of tissues and involved in a large variety of cellular functions. Several classes of the myosin superfamily are expressed in the nervous system; among them, non-muscle myosin II (NM II) is expressed in both neurons and non-neuronal brain cells, such as astrocytes, oligodendrocytes, endothelial cells, and microglia. In the nervous system, NM II modulates a variety of functions, such as vesicle transport, phagocytosis, cell migration, cell adhesion and morphology, secretion, transcription, and cytokinesis, as well as playing key roles during brain development, inflammation, repair, and myelination functions. In this review, we will provide a brief overview of recent emerging roles of NM II in resting and activated microglia cells, the principal regulators of immune processes in the central nervous system (CNS) in both physiological and pathological conditions. When stimulated, microglial cells react and produce a number of mediators, such as pro-inflammatory cytokines, free radicals, and nitric oxide, that enhance inflammation and contribute to neurodegenerative diseases. Inhibition of NM II could be a new therapeutic target to treat or to prevent CNS diseases.


Assuntos
Microglia/metabolismo , Miosina Tipo II/metabolismo , Animais , Biomarcadores , Movimento Celular/imunologia , Citoesqueleto/metabolismo , Humanos , Microglia/imunologia , Fagocitose/imunologia
6.
Int J Mol Sci ; 22(13)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206170

RESUMO

Pleiotrophin (PTN) is a neurotrophic factor that regulates glial responses in animal models of different types of central nervous system (CNS) injuries. PTN is upregulated in the brain in different pathologies characterized by exacerbated neuroinflammation, including Parkinson's disease. PTN is an endogenous inhibitor of Receptor Protein Tyrosine Phosphatase (RPTP) ß/ζ, which is abundantly expressed in the CNS. Using a specific inhibitor of RPTPß/ζ (MY10), we aimed to assess whether the PTN/RPTPß/ζ axis is involved in neuronal and glial injury induced by the toxin MPP+. Treatment with the RPTPß/ζ inhibitor MY10 alone decreased the viability of both SH-SY5Y neuroblastoma cells and BV2 microglial cultures, suggesting that normal RPTPß/ζ function is involved in neuronal and microglial viability. We observed that PTN partially decreased the cytotoxicity induced by MPP+ in SH-SY5Y cells underpinning the neuroprotective function of PTN. However, MY10 did not seem to modulate the SH-SY5Y cell loss induced by MPP+. Interestingly, we observed that media from SH-SY5Y cells treated with MPP+ and MY10 decreases microglial viability but may elicit a neuroprotective response of microglia by upregulating Ptn expression. The data suggest a neurotrophic role of microglia in response to neuronal injury through upregulation of Ptn levels.


Assuntos
Proteínas de Transporte/metabolismo , Comunicação Celular , Citocinas/metabolismo , Microglia/metabolismo , Neurônios/metabolismo , Doença de Parkinson/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Animais , Humanos , Inflamação/metabolismo , Inflamação/fisiopatologia , Camundongos , Microglia/fisiologia , Modelos Biológicos , Neurônios/fisiologia , Doença de Parkinson/fisiopatologia , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/fisiologia , Transdução de Sinais
7.
Int J Mol Sci ; 22(12)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208781

RESUMO

Fibromyalgia is a chronic condition characterized by persistent widespread pain that significantly reduces quality of life in patients. The purinergic P2X7 receptor (P2X7R) seems to be involved in different pain states and neuroinflammation. The purpose of this study is to investigate the positive effects of P2X7R inhibition by the antagonist Brilliant Blue G (BBG) in a rat model of reserpine-induced fibromyalgia. Sprague-Dawley male rats were injected with 1 mg/kg of reserpine for three consecutive days. Later, animals were administered BBG (50 mg/kg) intraperitoneally for seven days. Reserpine injections induced a significant increase in pain pro-inflammatory mediators as well as a significant increase in neuroinflammation. Chronic pain, in turn, led to depressive-like symptoms and reduced neurogenesis. Blockage of P2X7R by BBG administrations is able to attenuate the behavioral deficits, pain mediators and microglial activation induced by reserpine injection. Additionally, BBG prevents NLRP3 inflammasome activation and consequently the release of active interleukin (IL)-1 and IL-18, involved in the activation of nociceptors. In conclusion, these results suggest that inhibition of P2X7R should be further investigated to develop a potential approach for the management of fibromyalgia.


Assuntos
Fibromialgia/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Antagonistas do Receptor Purinérgico P2X/farmacologia , Receptores Purinérgicos P2X7/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/fisiopatologia , Degranulação Celular/efeitos dos fármacos , Gerenciamento Clínico , Modelos Animais de Doenças , Fibromialgia/tratamento farmacológico , Fibromialgia/etiologia , Inflamassomos/metabolismo , Mastócitos/efeitos dos fármacos , Mastócitos/imunologia , Mastócitos/metabolismo , Microglia/efeitos dos fármacos , Microglia/metabolismo , Neurogênese/efeitos dos fármacos , Ratos
8.
Int J Mol Sci ; 22(13)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209586

RESUMO

Amyloid beta (Aß)-induced abnormal neuroinflammation is recognized as a major pathological feature of Alzheimer's disease (AD), which results in memory impairment. Research exploring low-grade systemic inflammation and its impact on the development and progression of neurodegenerative disease has increased. A particular research focus has been whether systemic inflammation arises only as a secondary effect of disease, or it is also a cause of pathology. The inflammasomes, and more specifically the NLRP3 inflammasome, are crucial components of the innate immune system and are usually activated in response to infection or tissue damage. Although inflammasome activation plays critical roles against various pathogens in host defense, overactivation of inflammasome contributes to the pathogenesis of inflammatory diseases, including acute central nervous system (CNS) injuries and chronic neurodegenerative diseases, such as AD. This review summarizes the current literature on the role of the NLRP3 inflammasome in the pathogenesis of AD, and its involvement in infections, particularly SARS-CoV-2. NLRP3 might represent the crossroad between the hypothesized neurodegeneration and the primary COVID-19 infection.


Assuntos
Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Doença de Alzheimer/metabolismo , Animais , Coronavirus/patogenicidade , Humanos , Imunidade Inata , Microglia/metabolismo , Viroses/imunologia , Viroses/patologia
9.
Int J Mol Sci ; 22(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204581

RESUMO

Parkinson's disease (PD) is considered the most common disorder of synucleinopathy, which is characterised by intracellular inclusions of aggregated and misfolded α-synuclein (α-syn) protein in various brain regions, and the loss of dopaminergic neurons. During the early prodromal phase of PD, synaptic alterations happen before cell death, which is linked to the synaptic accumulation of toxic α-syn specifically in the presynaptic terminals, affecting neurotransmitter release. The oligomers and protofibrils of α-syn are the most toxic species, and their overexpression impairs the distribution and activation of synaptic proteins, such as the SNARE complex, preventing neurotransmitter exocytosis and neuronal synaptic communication. In the last few years, the role of the immune system in PD has been increasingly considered. Microglial and astrocyte activation, the gene expression of proinflammatory factors, and the infiltration of immune cells from the periphery to the central nervous system (CNS) represent the main features of the inflammatory response. One of the actors of these processes is α-syn accumulation. In light of this, here, we provide a systematic review of PD-related α-syn and inflammation inter-players.


Assuntos
Suscetibilidade a Doenças , Doença de Parkinson/metabolismo , Sinapses/metabolismo , alfa-Sinucleína/metabolismo , Imunidade Adaptativa , Animais , Astrócitos/metabolismo , Astrócitos/patologia , Biomarcadores , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/patologia , Humanos , Imunidade Inata , Microglia/imunologia , Microglia/metabolismo , Microglia/patologia , Doença de Parkinson/etiologia , Doença de Parkinson/patologia , Sinapses/imunologia , alfa-Sinucleína/genética
10.
Int J Mol Sci ; 22(13)2021 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-34281258

RESUMO

Infection by Proteus mirabilis causes urinary stones and catheter incrustation due to ammonia formed by urease (PMU), one of its virulence factors. Non-enzymatic properties, such as pro-inflammatory and neurotoxic activities, were previously reported for distinct ureases, including that of the gastric pathogen Helicobacter pylori. Here, PMU was assayed on isolated cells to evaluate its non-enzymatic properties. Purified PMU (nanomolar range) was tested in human (platelets, HEK293 and SH-SY5Y) cells, and in murine microglia (BV-2). PMU promoted platelet aggregation. It did not affect cellular viability and no ammonia was detected in the cultures' supernatants. PMU-treated HEK293 cells acquired a pro-inflammatory phenotype, producing reactive oxygen species (ROS) and cytokines IL-1ß and TNF-α. SH-SY5Y cells stimulated with PMU showed high levels of intracellular Ca2+ and ROS production, but unlike BV-2 cells, SH-SY5Y did not synthesize TNF-α and IL-1ß. Texas Red-labeled PMU was found in the cytoplasm and in the nucleus of all cell types. Bioinformatic analysis revealed two bipartite nuclear localization sequences in PMU. We have shown that PMU, besides urinary stone formation, can potentially contribute in other ways to pathogenesis. Our data suggest that PMU triggers pro-inflammatory effects and may affect cells beyond the renal system, indicating a possible role in extra-urinary diseases.


Assuntos
Proteus mirabilis/enzimologia , Proteus mirabilis/patogenicidade , Urease/metabolismo , Urease/toxicidade , Sequência de Aminoácidos , Animais , Cálcio/metabolismo , Linhagem Celular , Núcleo Celular/metabolismo , Células HEK293 , Humanos , Técnicas In Vitro , Camundongos , Microglia/efeitos dos fármacos , Microglia/metabolismo , Microglia/microbiologia , Modelos Moleculares , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/microbiologia , Neurotoxinas/química , Neurotoxinas/metabolismo , Neurotoxinas/toxicidade , Sinais de Localização Nuclear , Agregação Plaquetária/efeitos dos fármacos , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/toxicidade , Urease/química , Virulência/fisiologia
11.
Int J Mol Sci ; 22(11)2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34070609

RESUMO

Parkinson's disease (PD) is a neurodegenerative disorder where misfolded alpha-synuclein-enriched aggregates called Lewy bodies are central in pathogenesis. No neuroprotective or disease-modifying treatments are currently available. Parkinson's disease is considered a multifactorial disease and evidence from multiple patient studies and animal models has shown a significant immune component during the course of the disease, highlighting immunomodulation as a potential treatment strategy. The immune changes occur centrally, involving microglia and astrocytes but also peripherally with changes to the innate and adaptive immune system. Here, we review current understanding of different components of the PD immune response with a particular emphasis on the leukotriene pathway. We will also describe evidence of montelukast, a leukotriene receptor antagonist, as a possible anti-inflammatory treatment for PD.


Assuntos
Acetatos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Ciclopropanos/uso terapêutico , Antagonistas de Leucotrienos/uso terapêutico , Doença de Parkinson , Quinolinas/uso terapêutico , Sulfetos/uso terapêutico , Astrócitos/metabolismo , Astrócitos/patologia , Humanos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/patologia , Corpos de Lewy/metabolismo , Corpos de Lewy/patologia , Microglia/metabolismo , Microglia/patologia , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Receptores de Leucotrienos/metabolismo
12.
Int J Mol Sci ; 22(11)2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-34072307

RESUMO

A change in microglia structure, signaling, or function is commonly associated with neurodegeneration. This is evident in the patient population, animal models, and targeted in vitro assays. While there is a clear association, it is not evident that microglia serve as an initiator of neurodegeneration. Rather, the dynamics imply a close interaction between the various cell types and structures in the brain that orchestrate the injury and repair responses. Communication between microglia and neurons contributes to the physiological phenotype of microglia maintaining cells in a surveillance state and allows the cells to respond to events occurring in their environment. Interactions between microglia and astrocytes is not as well characterized, nor are interactions with other members of the neurovascular unit; however, given the influence of systemic factors on neuroinflammation and disease progression, such interactions likely represent significant contributes to any neurodegenerative process. In addition, they offer multiple target sites/processes by which environmental exposures could contribute to neurodegenerative disease. Thus, microglia at least play a role as a significant other with an equal partnership; however, claiming a role as an initiator of neurodegeneration remains somewhat controversial.


Assuntos
Suscetibilidade a Doenças , Microglia/metabolismo , Degeneração Neural/etiologia , Degeneração Neural/metabolismo , Doenças Neurodegenerativas/etiologia , Doenças Neurodegenerativas/metabolismo , Animais , Biomarcadores , Comunicação Celular , Polaridade Celular , Regulação da Expressão Gênica , Humanos , Microglia/imunologia , Microglia/patologia , Degeneração Neural/patologia , Doenças Neurodegenerativas/patologia , Neurônios/metabolismo , Fagocitose/genética , Fagocitose/imunologia , Receptores de Reconhecimento de Padrão/genética , Receptores de Reconhecimento de Padrão/metabolismo , Transdução de Sinais
13.
Int J Mol Sci ; 22(11)2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34074054

RESUMO

Alzheimer's disease (AD) is thought to be caused by amyloid-ß (Aß) accumulation in the central nervous system due to deficient clearance. The aim of the present study was to investigate the effect of ganoderic acid A (GAA) on Aß clearance in microglia and its anti-AD activity. Aß degradation in BV2 microglial cells was determined using an intracellular Aß clearance assay. GAA stimulated autophagosome formation via the Axl receptor tyrosine kinase (Axl)/RAC/CDC42-activated kinase 1 (Pak1) pathway was determined by Western blot analyses, and fluorescence-labeled Aß42 was localized in lysosomes in confocal laser microscopy images. The in vivo anti-AD activity of GAA was evaluated by object recognition and Morris water maze (MWM) tests in an AD mouse model following intracerebroventricular injection of aggregated Aß42. The autophagy level in the hippocampus was assayed by immunohistochemical assessment against microtubule-associated proteins 1A/1B light-chain 3B (LC3B). Intracellular Aß42 levels were significantly reduced by GAA treatment in microglial cells. Additionally, GAA activated autophagy according to increased LC3B-II levels, with this increased autophagy stimulated by upregulating Axl and Pak1 phosphorylation. The effect of eliminating Aß by GAA through autophagy was reversed by R428, an Axl inhibitor, or IPA-3, a Pak1 inhibitor. Consistent with the cell-based assay, GAA ameliorated cognitive deficiency and reduced Aß42 levels in an AD mouse model. Furthermore, LC3B expression in the hippocampus was up-regulated by GAA treatment, with these GAA-specific effects abolished by R428. GAA promoted Aß clearance by enhancing autophagy via the Axl/Pak1 signaling pathway in microglial cells and ameliorated cognitive deficiency in an AD mouse model.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Autofagia/efeitos dos fármacos , Ácidos Heptanoicos/farmacologia , Lanosterol/análogos & derivados , Microglia/efeitos dos fármacos , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Animais , Autofagossomos/efeitos dos fármacos , Autofagossomos/metabolismo , Autofagia/genética , Linhagem Celular , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/patologia , Imuno-Histoquímica , Lanosterol/farmacologia , Lisossomos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/metabolismo , Microglia/patologia , Teste do Labirinto Aquático de Morris/efeitos dos fármacos , Fosforilação , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Quinases Ativadas por p21/antagonistas & inibidores , Quinases Ativadas por p21/metabolismo
14.
Molecules ; 26(9)2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-34064330

RESUMO

Several genetic studies have identified a rare variant of triggering receptor expressed on myeloid cells 2 (TREM2) as a risk factor for Alzheimer's disease (AD). However, findings on the effects of TREM2 on Aß deposition are quite inconsistent in animal studies, requiring further investigation. In this study, we investigated whether elevation of TREM2 mitigates Aß pathology in TgCRND8 mice. We found that peripheral nerve injury resulted in a robust elevation of TREM2 exclusively in reactive microglia in the ipsilateral spinal cord of aged TgCRND8 mice at the age of 20 months. TREM2 expression appeared on day 1 post-injury and the upregulation was maintained for at least 28 days. Compared to the contralateral side, neither amyloid beta plaque load nor soluble Aß40 and Aß42 levels were attenuated upon TREM2 induction. We further showed direct evidence that TREM2 elevation in reactive microglia did not affect amyloid-ß pathology in plaque-bearing TgCRND8 mice by applying anti-TREM2 neutralizing antibody to selectively block TREM2. Our results question the ability of TREM2 to ameliorate established Aß pathology, discouraging future development of disease-modifying pharmacological treatments targeting TREM2 in the late stage of AD.


Assuntos
Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Glicoproteínas de Membrana/metabolismo , Microglia/metabolismo , Microglia/patologia , Receptores Imunológicos/metabolismo , Envelhecimento/patologia , Animais , Plexo Braquial , Proteínas de Ligação ao Cálcio/metabolismo , Modelos Animais de Doenças , Masculino , Camundongos Transgênicos , Proteínas dos Microfilamentos/metabolismo , Nervos Periféricos/patologia , Medula Espinal/metabolismo , Medula Espinal/patologia , Corno Dorsal da Medula Espinal/patologia
15.
Int J Mol Sci ; 22(10)2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34069782

RESUMO

Parkinson's disease (PD) is the second most common neurodegenerative disorder, mainly characterized by motor deficits correlated with progressive dopaminergic neuronal loss in the substantia nigra pars compacta (SN). Necroptosis is a caspase-independent form of regulated cell death mediated by the concerted action of receptor-interacting protein 3 (RIP3) and the pseudokinase mixed lineage domain-like protein (MLKL). It is also usually dependent on RIP1 kinase activity, influenced by further cellular clues. Importantly, necroptosis appears to be strongly linked to several neurodegenerative diseases, including PD. Here, we aimed at identifying novel chemical inhibitors of necroptosis in a PD-mimicking model, by conducting a two-step screening. Firstly, we phenotypically screened a library of 31 small molecules using a cellular model of necroptosis and, thereafter, the hit compound effect was validated in vivo in a sub-acute 1-methyl-1-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP) PD-related mouse model. From the initial compounds, we identified one hit-Oxa12-that strongly inhibited necroptosis induced by the pan-caspase inhibitor zVAD-fmk in the BV2 murine microglia cell line. More importantly, mice exposed to MPTP and further treated with Oxa12 showed protection against MPTP-induced dopaminergic neuronal loss in the SN and striatum. In conclusion, we identified Oxa12 as a hit compound that represents a new chemotype to tackle necroptosis. Oxa12 displays in vivo effects, making this compound a drug candidate for further optimization to attenuate PD pathogenesis.


Assuntos
Neurônios Dopaminérgicos/metabolismo , Necroptose/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Encéfalo/metabolismo , Morte Celular/efeitos dos fármacos , Corpo Estriado/metabolismo , Modelos Animais de Doenças , Dopamina/metabolismo , Neurônios Dopaminérgicos/efeitos dos fármacos , Proteínas Ativadoras de GTPase/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/metabolismo , Necroptose/fisiologia , Doenças Neurodegenerativas/metabolismo , Doença de Parkinson/metabolismo , Parte Compacta da Substância Negra/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Substância Negra/metabolismo
16.
Int J Mol Sci ; 22(11)2021 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-34070933

RESUMO

Hippocampal damage after traumatic brain injury (TBI) is associated with late posttraumatic conditions, such as depression, cognitive decline and epilepsy. Mechanisms of selective hippocampal damage after TBI are not well understood. In this study, using rat TBI model (lateral fluid percussion cortical injury), we assessed potential association of immediate posttraumatic seizures and changes in corticosterone (CS) levels with neuroinflammation and neuronal cell loss in the hippocampus. Indices of distant hippocampal damage (neurodegeneration and neuroinflammation) were assessed using histological analysis (Nissl staining, Iba-1 immunohistochemical staining) and ELISA (IL-1ß and CS) 1, 3, 7 and 14 days after TBI or sham operation in male Wistar rats (n = 146). IL-1ß was elevated only in the ipsilateral hippocampus on day 1 after trauma. CS peak was detected on day 3 in blood, the ipsilateral and contralateral hippocampus. Neuronal cell loss in the hippocampus was demonstrated bilaterally; in the ipsilateral hippocampus it started earlier than in the contralateral. Microglial activation was evident in the hippocampus bilaterally on day 7 after TBI. The duration of immediate seizures correlated with CS elevation, levels of IL-1ß and neuronal loss in the hippocampus. The data suggest potential association of immediate post-traumatic seizures with CS-dependent neuroinflammation-mediated distant hippocampal damage.


Assuntos
Lesões Encefálicas Traumáticas/metabolismo , Corticosterona/sangue , Hipocampo/metabolismo , Microglia/metabolismo , Neurônios/metabolismo , Convulsões/metabolismo , Animais , Biomarcadores/metabolismo , Lesões Encefálicas Traumáticas/patologia , Lesões Encefálicas Traumáticas/fisiopatologia , Contagem de Células , Morte Celular , Modelos Animais de Doenças , Hipocampo/patologia , Hipocampo/fisiopatologia , Inflamação , Interleucina-1beta/biossíntese , Masculino , Microglia/patologia , Neurônios/patologia , Ratos , Ratos Wistar , Convulsões/patologia , Convulsões/fisiopatologia , Fatores de Tempo
17.
Int J Mol Sci ; 22(10)2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-34067536

RESUMO

Several virus-induced models were used to study the underlying mechanisms of multiple sclerosis (MS). The infection of susceptible mice with Theiler's murine encephalomyelitis virus (TMEV) establishes persistent viral infections and induces chronic inflammatory demyelinating disease. In this review, the innate and adaptive immune responses to TMEV are discussed to better understand the pathogenic mechanisms of viral infections. Professional (dendritic cells (DCs), macrophages, and B cells) and non-professional (microglia, astrocytes, and oligodendrocytes) antigen-presenting cells (APCs) are the major cell populations permissive to viral infection and involved in cytokine production. The levels of viral loads and cytokine production in the APCs correspond to the degrees of susceptibility of the mice to the TMEV-induced demyelinating diseases. TMEV infection leads to the activation of cytokine production via TLRs and MDA-5 coupled with NF-κB activation, which is required for TMEV replication. These activation signals further amplify the cytokine production and viral loads, promote the differentiation of pathogenic Th17 responses, and prevent cellular apoptosis, enabling viral persistence. Among the many chemokines and cytokines induced after viral infection, IFN α/ß plays an essential role in the downstream expression of costimulatory molecules in APCs. The excessive levels of cytokine production after viral infection facilitate the pathogenesis of TMEV-induced demyelinating disease. In particular, IL-6 and IL-1ß play critical roles in the development of pathogenic Th17 responses to viral antigens and autoantigens. These cytokines, together with TLR2, may preferentially generate deficient FoxP3+CD25- regulatory cells converting to Th17. These cytokines also inhibit the apoptosis of TMEV-infected cells and cytolytic function of CD8+ T lymphocytes (CTLs) and prolong the survival of B cells reactive to viral and self-antigens, which preferentially stimulate Th17 responses.


Assuntos
Doenças Desmielinizantes/imunologia , Esclerose Múltipla/imunologia , Theilovirus/fisiologia , Imunidade Adaptativa/imunologia , Animais , Células Apresentadoras de Antígenos/metabolismo , Astrócitos/metabolismo , Infecções por Cardiovirus/imunologia , Infecções por Cardiovirus/metabolismo , Infecções por Cardiovirus/virologia , Citocinas , Doenças Desmielinizantes/patologia , Modelos Animais de Doenças , Humanos , Imunidade Inata/imunologia , Camundongos , Microglia/metabolismo , Esclerose Múltipla/metabolismo , Oligodendroglia/metabolismo , Transdução de Sinais/imunologia , Theilovirus/patogenicidade
18.
Int J Mol Sci ; 22(9)2021 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-34065042

RESUMO

Glutathione (GSH) is the most abundant non-protein thiol, and plays crucial roles in the antioxidant defense system and the maintenance of redox homeostasis in neurons. GSH depletion in the brain is a common finding in patients with neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease, and can cause neurodegeneration prior to disease onset. Excitatory amino acid carrier 1 (EAAC1), a sodium-dependent glutamate/cysteine transporter that is selectively present in neurons, plays a central role in the regulation of neuronal GSH production. The expression of EAAC1 is posttranslationally controlled by the glutamate transporter-associated protein 3-18 (GTRAP3-18) or miR-96-5p in neurons. The regulatory mechanism of neuronal GSH production mediated by EAAC1 may be a new target in therapeutic strategies for these neurodegenerative diseases. This review describes the regulatory mechanism of neuronal GSH production and its potential therapeutic application in the treatment of neurodegenerative diseases.


Assuntos
Encéfalo/metabolismo , Glutationa/metabolismo , Animais , Antioxidantes/metabolismo , Biomarcadores , Encéfalo/efeitos dos fármacos , Gerenciamento Clínico , Suscetibilidade a Doenças , Transportador 3 de Aminoácido Excitatório/genética , Transportador 3 de Aminoácido Excitatório/metabolismo , Regulação da Expressão Gênica , Proteínas de Transporte de Glutamato da Membrana Plasmática/metabolismo , Glutationa/farmacologia , Glutationa/uso terapêutico , Humanos , Redes e Vias Metabólicas , Microglia/metabolismo , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/etiologia , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , Neurônios/metabolismo , Oxirredução , Espécies Reativas de Oxigênio/metabolismo
19.
Nat Genet ; 53(6): 861-868, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34083789

RESUMO

Microglia, the tissue-resident macrophages of the central nervous system (CNS), play critical roles in immune defense, development and homeostasis. However, isolating microglia from humans in large numbers is challenging. Here, we profiled gene expression variation in primary human microglia isolated from 141 patients undergoing neurosurgery. Using single-cell and bulk RNA sequencing, we identify how age, sex and clinical pathology influence microglia gene expression and which genetic variants have microglia-specific functions using expression quantitative trait loci (eQTL) mapping. We follow up one of our findings using a human induced pluripotent stem cell-based macrophage model to fine-map a candidate causal variant for Alzheimer's disease at the BIN1 locus. Our study provides a population-scale transcriptional map of a critically important cell for human CNS development and disease.


Assuntos
Regulação da Expressão Gênica , Microglia/metabolismo , Transcrição Genética , Doença de Alzheimer/genética , Humanos , Modelos Genéticos , Locos de Características Quantitativas/genética , Análise de Sequência de RNA , Análise de Célula Única
20.
Neuroscience ; 468: 186-198, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34082066

RESUMO

Synucleinopathy disorders are characterized by aggregates of α-synuclein (α-syn), which engage microglia to elicit a neuroinflammatory response. Here, we determined the gene expression and DNA methylation changes in microglia induced by aggregate α-syn. Transgenic murine Thy-1 promoter (mThy1)-Asyn mice overexpressing human α-syn are a model of synucleinopathy. Microglia from 3 and 13-month-old mice were used to isolate nucleic acids for methylated DNA and RNA-sequencing. α-Syn-regulated changes in gene expression and genomic methylation were determined and examined for functional enrichment followed by network analysis to further elucidate possible connections within the data. Microglial DNA isolated from our 3-month cohort had 5315 differentially methylated gene (DMG) changes, while RNA levels demonstrated a change in 119 differentially expressed genes (DEGs) between mThy1-Asyn mice and wild-type littermate controls. The 3-month DEGs and DMGs were highly associated with adhesion and migration signaling, suggesting a phenotypic transition from resting to active microglia. We observed 3742 DMGs and 3766 DEGs in 13-month mThy1-Asyn mice. These genes were often related to adhesion, migration, cell cycle, cellular metabolism, and immune response. Network analysis also showed increased cell mobility and inflammatory functions at 3 months, shifting to cell cycle, immune response, and metabolism changes at 13 months. We observed significant α-syn-induced methylation and gene expression changes in microglia. Our data suggest that α-syn overexpression initiates microglial activation leading to neuroinflammation and cellular metabolic stresses, which is associated with disease progression.


Assuntos
Microglia , alfa-Sinucleína , Animais , Metilação de DNA , Modelos Animais de Doenças , Expressão Gênica , Inflamação , Camundongos , Camundongos Endogâmicos C57BL , Microglia/metabolismo , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo
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