Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 96.439
Filtrar
1.
Nat Commun ; 12(1): 5220, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34471104

RESUMO

Advancement in human induced pluripotent stem cell (iPSC) neuron and microglial differentiation protocols allow for disease modeling using physiologically relevant cells. However, iPSC differentiation and culturing protocols have posed challenges to maintaining consistency. Here, we generated an automated, consistent, and long-term culturing platform of human iPSC neurons, astrocytes, and microglia. Using this platform we generated a iPSC AD model using human derived cells, which showed signs of Aß plaques, dystrophic neurites around plaques, synapse loss, dendrite retraction, axon fragmentation, phospho-Tau induction, and neuronal cell death in one model. We showed that the human iPSC microglia internalized and compacted Aß to generate and surround the plaques, thereby conferring some neuroprotection. We investigated the mechanism of action of anti-Aß antibodies protection and found that they protected neurons from these pathologies and were most effective before pTau induction. Taken together, these results suggest that this model can facilitate target discovery and drug development efforts.


Assuntos
Doença de Alzheimer/metabolismo , Astrócitos/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Microglia/metabolismo , Neurônios/metabolismo , Diferenciação Celular , Humanos , Cinética , Placa Amiloide , Sinapses/metabolismo
2.
Nat Commun ; 12(1): 4087, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34471112

RESUMO

We utilized forebrain organoids generated from induced pluripotent stem cells of patients with a syndromic form of Autism Spectrum Disorder (ASD) with a homozygous protein-truncating mutation in CNTNAP2, to study its effects on embryonic cortical development. Patients with this mutation present with clinical characteristics of brain overgrowth. Patient-derived forebrain organoids displayed an increase in volume and total cell number that is driven by increased neural progenitor proliferation. Single-cell RNA sequencing revealed PFC-excitatory neurons to be the key cell types expressing CNTNAP2. Gene ontology analysis of differentially expressed genes (DEgenes) corroborates aberrant cellular proliferation. Moreover, the DEgenes are enriched for ASD-associated genes. The cell-type-specific signature genes of the CNTNAP2-expressing neurons are associated with clinical phenotypes previously described in patients. The organoid overgrowth phenotypes were largely rescued after correction of the mutation using CRISPR-Cas9. This CNTNAP2-organoid model provides opportunity for further mechanistic inquiry and development of new therapeutic strategies for ASD.


Assuntos
Transtorno do Espectro Autista/metabolismo , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Organoides/metabolismo , Prosencéfalo/metabolismo , Adolescente , Transtorno do Espectro Autista/genética , Diferenciação Celular , Proliferação de Células , Criança , Feminino , Predisposição Genética para Doença/genética , Humanos , Células-Tronco Pluripotentes Induzidas , Proteínas de Membrana/genética , Mutação , Proteínas do Tecido Nervoso/genética , Neurônios/metabolismo , Fenótipo , Análise de Sequência de RNA
3.
Molecules ; 26(17)2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34500626

RESUMO

We investigated the protective effect and mechanisms of apigenin against cognitive impairments in a scopolamine-injected mouse model. Our results showed that intraperitoneal (i.p.) injection of scopolamine leads to learning and memory dysfunction, whereas the administration of apigenin (synthetic compound, 100 and 200 mg/kg/day) improved cognitive ability, which was confirmed by behavioral tests such as the T-maze test, novel objective recognition test, and Morris water maze test in mice. In addition, scopolamine-induced lipid peroxidation in the brain was attenuated by administration of apigenin. To further evaluate the protective mechanisms of apigenin on cognitive and memory function, Western blot analysis was carried out. Administration of apigenin decreased the B-cell lymphoma 2-associated X/B-cell lymphoma 2 (Bax/Bcl-2) ratio and suppressed caspase-3 and poly ADP ribose polymerase cleavage. Furthermore, apigenin down-regulated the ß-site amyloid precursor protein-cleaving enzyme, along with presenilin 1 (PS1) and PS2 protein levels. Apigenin-administered mice showed lower protein levels of a receptor for advanced glycation end-products, whereas insulin-degrading enzyme, brain-derived neurotrophic factor (BDNF), and tropomyosin receptor kinase B (TrkB) expression were promoted by treatment with apigenin. Therefore, this study demonstrated that apigenin is an active substance that can improve cognitive and memory functions by regulating apoptosis, amyloidogenesis, and BDNF/TrkB signaling pathways.


Assuntos
Apigenina/farmacologia , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/tratamento farmacológico , Neurônios/efeitos dos fármacos , Escopolamina/farmacologia , Animais , Apoptose/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Disfunção Cognitiva/metabolismo , Modelos Animais de Doenças , Peroxidação de Lipídeos/efeitos dos fármacos , Memória/efeitos dos fármacos , Camundongos , Neurônios/metabolismo , Fármacos Neuroprotetores/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Receptor trkB/metabolismo , Transdução de Sinais/efeitos dos fármacos
4.
FASEB J ; 35(9): e21827, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34383980

RESUMO

Neuron-derived orphan receptor 1, NR4A3 (Nor1)/NR4A3 is an orphan nuclear receptor involved in the transcriptional control of developmental and neurological functions. Oxidative stress-induced conditions are primarily associated with neurological defects in humans, yet the impact on Nor1-mediated transcription of neuronal genes remains with unknown mechanism. Here, we demonstrate that Nor1 is a non-conventional target of SUMO2/3 conjugation at Lys-137 contained in an atypic ψKxSP motif referred to as the pSuM. Nor1 pSuM SUMOylation differs from the canonical process with the obligate phosphorylation of Ser-139 by Ras signaling to create the required negatively charged interface for SUMOylation. Additional phosphorylation at sites flanking the pSuM is also mediated by the coordinated action of protein kinase casein kinase 2 to function as a small ubiquitin-like modifier enhancer, regulating Nor1-mediated transcription and proteasomal degradation. Nor1 responsive genes involved in cell proliferation and metabolism, such as activating transcription factor 3, cyclin D1, CASP8 and FADD-like apoptosis regulator, and enolase 3 were upregulated in response to pSuM disruption in mouse HT-22 hippocampal neuronal cells and human neuroblastoma SH-SY5Y cells. We also identified critical antioxidant genes, such as catalase, superoxide dismutase 1, and microsomal glutathione S-transferase 2, as responsive targets of Nor1 under pSuM regulation. Nor1 SUMOylation impaired gene transcription through less effective Nor1 chromatin binding and reduced enrichment of histone H3K27ac marks to gene promoters. These effects resulted in decreased neuronal cell growth, increased apoptosis, and reduced survival to oxidative stress damage, underlying the role of pSuM-modified Nor1 in redox homeostasis. Our findings uncover a hierarchical post-translational mechanism that dictates Nor1 non-canonical SUMOylation, disrupting Nor1 transcriptional competence, and neuroprotective redox sensitivity.


Assuntos
Sobrevivência Celular/genética , Proteínas de Ligação a DNA/genética , Receptores de Esteroides/genética , Receptores dos Hormônios Tireóideos/genética , Sumoilação/genética , Animais , Apoptose/genética , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/genética , Quinase do Ponto de Checagem 2/genética , Regulação da Expressão Gênica/genética , Células HEK293 , Hipocampo/metabolismo , Homeostase/genética , Humanos , Camundongos , Neuroblastoma/genética , Neurônios/metabolismo , Oxirredução , Estresse Oxidativo/genética , Fosforilação/genética , Regiões Promotoras Genéticas/genética , Processamento de Proteína Pós-Traducional/genética , Transcrição Genética/genética , Ativação Transcricional/genética , Regulação para Cima/genética
5.
Nat Commun ; 12(1): 4912, 2021 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-34389721

RESUMO

Polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) hybrid systems typically use complex protein-protein interactions to facilitate direct transfer of intermediates between these multimodular megaenzymes. In the canal-associated neurons (CANs) of Caenorhabditis elegans, PKS-1 and NRPS-1 produce the nemamides, the only known hybrid polyketide-nonribosomal peptides biosynthesized by animals, through a poorly understood mechanism. Here, we use genome editing and mass spectrometry to map the roles of individual PKS-1 and NRPS-1 enzymatic domains in nemamide biosynthesis. Furthermore, we show that nemamide biosynthesis requires at least five additional enzymes expressed in the CANs that are encoded by genes distributed across the worm genome. We identify the roles of these enzymes and discover a mechanism for trafficking intermediates between a PKS and an NRPS. Specifically, the enzyme PKAL-1 activates an advanced polyketide intermediate as an adenylate and directly loads it onto a carrier protein in NRPS-1. This trafficking mechanism provides a means by which a PKS-NRPS system can expand its biosynthetic potential and is likely important for the regulation of nemamide biosynthesis.


Assuntos
Vias Biossintéticas/genética , Proteínas de Caenorhabditis elegans/genética , Peptídeo Sintases/genética , Peptídeos/metabolismo , Policetídeo Sintases/genética , Policetídeos/metabolismo , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/citologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Cromatografia Líquida/métodos , Enzimas/genética , Enzimas/metabolismo , Expressão Gênica , Espectrometria de Massas/métodos , Estrutura Molecular , Mutação , Neurônios/metabolismo , Peptídeo Sintases/metabolismo , Peptídeos/química , Policetídeo Sintases/metabolismo , Policetídeos/química
6.
Nat Commun ; 12(1): 4913, 2021 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-34389722

RESUMO

Epitranscriptomic mechanisms linking tRNA function and the brain proteome to cognition and complex behaviors are not well described. Here, we report bi-directional changes in depression-related behaviors after genetic disruption of neuronal tRNA cytosine methylation, including conditional ablation and transgene-derived overexpression of Nsun2 in the mouse prefrontal cortex (PFC). Neuronal Nsun2-deficiency was associated with a decrease in tRNA m5C levels, resulting in deficits in expression of 70% of tRNAGly isodecoders. Altogether, 1488/5820 proteins changed upon neuronal Nsun2-deficiency, in conjunction with glycine codon-specific defects in translational efficiencies. Loss of Gly-rich proteins critical for glutamatergic neurotransmission was associated with impaired synaptic signaling at PFC pyramidal neurons and defective contextual fear memory. Changes in the neuronal translatome were also associated with a 146% increase in glycine biosynthesis. These findings highlight the methylation sensitivity of glycinergic tRNAs in the adult PFC. Furthermore, they link synaptic plasticity and complex behaviors to epitranscriptomic modifications of cognate tRNAs and the proteomic homeostasis associated with specific amino acids.


Assuntos
Transtorno Depressivo/fisiopatologia , Epigênese Genética/genética , Metiltransferases/genética , Proteoma/metabolismo , RNA de Transferência/genética , Transmissão Sináptica/genética , Animais , Transtorno Depressivo/genética , Transtorno Depressivo/metabolismo , Perfilação da Expressão Gênica/métodos , Metiltransferases/deficiência , Metiltransferases/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Neurônios/metabolismo , Córtex Pré-Frontal/citologia , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/fisiologia , Proteômica/métodos , RNA de Transferência/metabolismo , Transdução de Sinais/genética
7.
Int J Mol Sci ; 22(15)2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34361042

RESUMO

Various neurodegenerative disorders are associated with human NTE/PNPLA6 dysfunction. Mechanisms of neuropathogenesis in these diseases are far from clearly elucidated. Hereditary spastic paraplegia belongs to a type of neurodegeneration associated with NTE/PNLPLA6 and is implicated in neuron death. In this study, we used Drosophila melanogaster to investigate the consequences of neuronal knockdown of swiss cheese (sws)-the evolutionarily conserved ortholog of human NTE/PNPLA6-in vivo. Adult flies with the knockdown show longevity decline, locomotor and memory deficits, severe neurodegeneration progression in the brain, reactive oxygen species level acceleration, mitochondria abnormalities and lipid droplet accumulation. Our results suggest that SWS/NTE/PNPLA6 dysfunction in neurons induces oxidative stress and lipid metabolism alterations, involving mitochondria dynamics and lipid droplet turnover in neurodegeneration pathogenesis. We propose that there is a complex mechanism in neurological diseases such as hereditary spastic paraplegia, which includes a stress reaction, engaging mitochondria, lipid droplets and endoplasmic reticulum interplay.


Assuntos
Encéfalo/metabolismo , Proteínas de Drosophila/metabolismo , Gotículas Lipídicas/metabolismo , Mitocôndrias/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Encéfalo/citologia , Proteínas de Drosophila/deficiência , Proteínas de Drosophila/genética , Drosophila melanogaster , Metabolismo dos Lipídeos , Mitocôndrias/ultraestrutura , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Neurônios/metabolismo , Estresse Oxidativo
8.
Life Sci ; 283: 119865, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34358549

RESUMO

AIMS: Stroke has risen to the fifth and third most common causes of death in the United States and the rest of the world, respectively. Vortioxetine (VTX) is a multimodal antidepressant agent that balances 5-HT receptors and represses the serotonin transporter. Our study aimed to examine the neuroprotective impacts of VTX against cerebral ischemia caused by occluding the middle cerebral artery (MCA). MAIN METHODS: Until the middle cerebral artery occlusion (MCAO) induction, VTX (10 mg/kg/day) was taken orally for 14 days. Behavioral assessments were carried out 24 h after the MCAO technique. The hippocampal and cortical tissues of the brain were isolated to assess the histological changes and the levels of the biochemical parameters. KEY FINDINGS: MCAO damage led to severe neurological deficits and histopathological damage. However, VTX improved MCAO-induced neurological deficits and ameliorated histopathological changes in both hippocampal and cortical tissues of MCAO rats. Western blot analysis showed increments of p-PERK, CHOP, ASK-1, NICD, HES-1, HES-5, and p-eIF2α expression levels in MCAO rats. Moreover, ELISA revealed an increase in the levels of ATF4, IRE1, Apaf-1, and HIF-1α, while VTX administration ameliorated most of these perturbations induced after MCAO injury. SIGNIFICANCE: This research suggests that VTX could be a potent neuroprotective agent against ischemic stroke by inhibiting a variety of oxidative, apoptotic, inflammatory, and endoplasmic reticulum stress pathways.


Assuntos
Fator 4 Ativador da Transcrição/metabolismo , Transtornos Cerebrovasculares/tratamento farmacológico , Fator de Iniciação 2 em Eucariotos/metabolismo , Neurônios/metabolismo , Traumatismo por Reperfusão/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição CHOP/metabolismo , Vortioxetina/farmacologia , eIF-2 Quinase/metabolismo , Animais , Transtornos Cerebrovasculares/metabolismo , Transtornos Cerebrovasculares/patologia , Masculino , Neurônios/patologia , Ratos , Ratos Wistar , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia
9.
Science ; 373(6557): 882-889, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34413232

RESUMO

Eukaryotic genomes contain domesticated genes from integrating viruses and mobile genetic elements. Among these are homologs of the capsid protein (known as Gag) of long terminal repeat (LTR) retrotransposons and retroviruses. We identified several mammalian Gag homologs that form virus-like particles and one LTR retrotransposon homolog, PEG10, that preferentially binds and facilitates vesicular secretion of its own messenger RNA (mRNA). We showed that the mRNA cargo of PEG10 can be reprogrammed by flanking genes of interest with Peg10's untranslated regions. Taking advantage of this reprogrammability, we developed selective endogenous encapsidation for cellular delivery (SEND) by engineering both mouse and human PEG10 to package, secrete, and deliver specific RNAs. Together, these results demonstrate that SEND is a modular platform suited for development as an efficient therapeutic delivery modality.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Proteínas de Ligação a DNA/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/metabolismo , Animais , Proteínas Reguladoras de Apoptose/química , Proteínas Reguladoras de Apoptose/genética , Capsídeo/metabolismo , Linhagem Celular , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Vesículas Extracelulares/metabolismo , Edição de Genes , Vetores Genéticos , Humanos , Camundongos , Neurônios/metabolismo , Domínios Proteicos , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética , Retroelementos , Transfecção , Regiões não Traduzidas , Regulação para Cima
10.
Nutrients ; 13(7)2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34371921

RESUMO

The study of different natural products can provide a wealth of bioactive compounds, and more interestingly, their combination can exert a new strategy for several neurodegenerative diseases with major public health importance, such as Alzheimer's disease (AD). Here, we investigated the synergistic neuroprotective effects of a mixed extract composed of docosahexaenoic acid, Ginkgo biloba, D-pinitol, and ursolic acid in several transgenic Caenorhabditis elegans (C. elegans) and a senescence-accelerated prone mice 8 (SAMP8) model. First, we found a significantly higher survival percentage in the C. elegans group treated with the natural product mixture compared to the single extract-treated groups. Likewise, we found a significantly increased lifespan in group of C. elegans treated with the natural product mixture compared to the other groups, suggesting synergistic effects. Remarkably, we determined a significant reduction in Aß plaque accumulation in the group of C. elegans treated with the natural product mixture compared to the other groups, confirming synergy. Finally, we demonstrated better cognitive performance in the group treated with the natural product mixture in both AD models (neuronal Aß C. elegans strain CL2355 and the SAMP8 mice model), confirming the molecular results and unraveling the synergist effects of this combination. Therefore, our results proved the potential of this new natural product mixture for AD therapeutic strategies.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Comportamento Animal/efeitos dos fármacos , Produtos Biológicos/farmacologia , Encéfalo/efeitos dos fármacos , Cognição/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Doença de Alzheimer/psicologia , Peptídeos beta-Amiloides/metabolismo , Animais , Animais Geneticamente Modificados , Encéfalo/metabolismo , Encéfalo/patologia , Caenorhabditis elegans/genética , Modelos Animais de Doenças , Longevidade , Camundongos , Neurônios/metabolismo , Neurônios/patologia , Estresse Oxidativo/efeitos dos fármacos , Placa Amiloide
11.
Science ; 373(6556)2021 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-34385370

RESUMO

The neurotransmitter acetylcholine (ACh) acts in part through a family of nicotinic ACh receptors (nAChRs), which mediate diverse physiological processes including muscle contraction, neurotransmission, and sensory transduction. Pharmacologically, nAChRs are responsible for tobacco addiction and are targeted by medicines for hypertension and dementia. Nicotinic AChRs were the first ion channels to be isolated. Recent studies have identified molecules that control nAChR biogenesis, trafficking, and function. These nAChR accessories include protein and chemical chaperones as well as auxiliary subunits. Whereas some factors act on many nAChRs, others are receptor specific. Discovery of these regulatory mechanisms is transforming nAChR research in cells and tissues ranging from central neurons to spinal ganglia to cochlear hair cells. Nicotinic AChR-specific accessories also enable drug discovery on high-confidence targets for psychiatric, neurological, and auditory disorders.


Assuntos
Chaperonas Moleculares/metabolismo , Neurônios/metabolismo , Proteínas/metabolismo , Receptores Nicotínicos/metabolismo , Animais , Membrana Celular/metabolismo , Descoberta de Drogas , Retículo Endoplasmático/metabolismo , Humanos , Ligantes , Músculo Esquelético/metabolismo , Neurofarmacologia , Nicotina/metabolismo , Subunidades Proteicas/metabolismo , Receptores Nicotínicos/química
12.
Nat Commun ; 12(1): 4857, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34381039

RESUMO

Physical exercise stimulates adult neurogenesis, yet the underlying mechanisms remain poorly understood. A fundamental component of the innate neuroregenerative capacity of zebrafish is the proliferative and neurogenic ability of the neural stem/progenitor cells. Here, we show that in the intact spinal cord, this plasticity response can be activated by physical exercise by demonstrating that the cholinergic neurotransmission from spinal locomotor neurons activates spinal neural stem/progenitor cells, leading to neurogenesis in the adult zebrafish. We also show that GABA acts in a non-synaptic fashion to maintain neural stem/progenitor cell quiescence in the spinal cord and that training-induced activation of neurogenesis requires a reduction of GABAA receptors. Furthermore, both pharmacological stimulation of cholinergic receptors, as well as interference with GABAergic signaling, promote functional recovery after spinal cord injury. Our findings provide a model for locomotor networks' activity-dependent neurogenesis during homeostasis and regeneration in the adult zebrafish spinal cord.


Assuntos
Locomoção , Neuroglia/metabolismo , Neurônios/metabolismo , Medula Espinal/crescimento & desenvolvimento , Animais , Interneurônios/metabolismo , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Neurogênese , Condicionamento Físico Animal , Receptores Colinérgicos/metabolismo , Receptores de GABA-A/metabolismo , Recuperação de Função Fisiológica , Medula Espinal/citologia , Medula Espinal/fisiologia , Transmissão Sináptica , Peixe-Zebra , Ácido gama-Aminobutírico/metabolismo
13.
Nat Commun ; 12(1): 4863, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34381050

RESUMO

Spreading of aggregate pathology across brain regions acts as a driver of disease progression in Tau-related neurodegeneration, including Alzheimer's disease (AD) and frontotemporal dementia. Aggregate seeds released from affected cells are internalized by naïve cells and induce the prion-like templating of soluble Tau into neurotoxic aggregates. Here we show in a cellular model system and in neurons that Clusterin, an abundant extracellular chaperone, strongly enhances Tau aggregate seeding. Upon interaction with Tau aggregates, Clusterin stabilizes highly potent, soluble seed species. Tau/Clusterin complexes enter recipient cells via endocytosis and compromise the endolysosomal compartment, allowing transfer to the cytosol where they propagate aggregation of endogenous Tau. Thus, upregulation of Clusterin, as observed in AD patients, may enhance Tau seeding and possibly accelerate the spreading of Tau pathology.


Assuntos
Clusterina/metabolismo , Agregação Patológica de Proteínas/metabolismo , Proteínas tau/metabolismo , Animais , Clusterina/genética , Progressão da Doença , Endocitose , Humanos , Camundongos , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , Neurônios/metabolismo , Neurônios/patologia , Agregação Patológica de Proteínas/patologia , Ligação Proteica , alfa-Sinucleína/metabolismo , Proteínas tau/genética
14.
Int J Mol Sci ; 22(16)2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34445224

RESUMO

The tightly localized noradrenergic neurons (NA) in the locus coeruleus (LC) are well recognized as essential for focused arousal and novelty-oriented responses, while many children with autism spectrum disorder (ASD) exhibit diminished attention, engagement and orienting to exogenous stimuli. This has led to the hypothesis that atypical LC activity may be involved in ASD. Oxytocin (OXT) neurons and receptors are known to play an important role in social behavior, pair bonding and cognitive processes and are under investigation as a potential treatment for ASD. However, little is known about the neurotransmission from hypothalamic paraventricular (PVN) OXT neurons to LC NA neurons. In this study, we test, in male and female rats, whether PVN OXT neurons excite LC neurons, whether oxytocin is released and involved in this neurotransmission, and whether activation of PVN OXT neurons alters novel object recognition. Using "oxytocin sniffer cells" (CHO cells that express the human oxytocin receptor and a Ca indicator) we show that there is release of OXT from hypothalamic PVN OXT fibers in the LC. Optogenetic excitation of PVN OXT fibers excites LC NA neurons by co-release of OXT and glutamate, and this neurotransmission is greater in males than females. In male, but not in female animals, chemogenetic activation of PVN OXT neurons increases attention to novel objects.


Assuntos
Atenção , Locus Cerúleo/metabolismo , Neurônios/metabolismo , Ocitocina/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , Caracteres Sexuais , Transmissão Sináptica , Animais , Células CHO , Cricetulus , Feminino , Humanos , Masculino , Ocitocina/genética , Ratos , Receptores de Ocitocina/genética , Receptores de Ocitocina/metabolismo
15.
Int J Mol Sci ; 22(16)2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34445634

RESUMO

Cannabinoids have been reported as orexigenic, i.e., as promoting food intake that, among others, is controlled by the so-called "hunger" hormone, ghrelin. The aim of this paper was to look for functional and/or molecular interactions between ghrelin GHSR1a and cannabinoid CB2 receptors at the central nervous system (CNS) level. In a heterologous system we identified CB2-GHSR1a receptor complexes with a particular heteromer print consisting of impairment of CB2 receptor/Gi-mediated signaling. The blockade was due to allosteric interactions within the heteromeric complex as it was reverted by antagonists of the GHSR1a receptor. Cannabinoids acting on the CB2 receptor did not affect cytosolic increases of calcium ions induced by ghrelin acting on the GHSR1a receptor. In situ proximity ligation imaging assays confirmed the expression of CB2-GHSR1a receptor complexes in both heterologous cells and primary striatal neurons. We tested heteromer expression in neurons from offspring of high-fat-diet mouse mothers as they have more risk to be obese. Interestingly, there was a marked upregulation of those complexes in striatal neurons from siblings of pregnant female mice under a high-fat diet.


Assuntos
Corpo Estriado/patologia , Dieta Hiperlipídica/efeitos adversos , Grelina/metabolismo , Neurônios/patologia , Obesidade/patologia , Receptor CB2 de Canabinoide/metabolismo , Receptores de Grelina/metabolismo , Animais , Canabinoides/farmacologia , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Feminino , Grelina/genética , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Obesidade/etiologia , Obesidade/metabolismo , Receptor CB2 de Canabinoide/genética , Receptores de Grelina/genética , Transdução de Sinais , Regulação para Cima
16.
EBioMedicine ; 70: 103512, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34333238

RESUMO

BACKGROUND: Neurologic manifestations are well-recognized features of coronavirus disease 2019 (COVID-19). However, the longitudinal association of biomarkers reflecting CNS impact and neurological symptoms is not known. We sought to determine whether plasma biomarkers of CNS injury were associated with neurologic sequelae after COVID-19. METHODS: Patients with confirmed acute COVID-19 were studied prospectively. Neurological symptoms were recorded during the acute phase of the disease and at six months follow-up, and blood samples were collected longitudinally. Healthy age-matched individuals were included as controls. We analysed plasma concentrations of neurofilament light-chain (NfL), glial fibrillary acidic protein (GFAp), and growth differentiation factor 15 (GDF-15). FINDINGS: One hundred patients with mild (n = 24), moderate (n = 28), and severe (n = 48) COVID-19 were followed for a median (IQR) of 225 (187-262) days. In the acute phase, patients with severe COVID-19 had higher concentrations of NfL than all other groups (all p < 0·001), and higher GFAp than controls (p < 0·001). GFAp was also significantly increased in moderate disease (p < 0·05) compared with controls. NfL (r = 0·53, p < 0·001) and GFAp (r = 0·39, p < 0·001) correlated with GDF-15 during the acute phase. After six months, NfL and GFAp concentrations had normalized, with no persisting group differences. Despite this, 50 patients reported persistent neurological symptoms, most commonly fatigue (n = 40), "brain-fog" (n = 29), and changes in cognition (n = 25). We found no correlation between persistent neurological symptoms and CNS injury biomarkers in the acute phase. INTERPRETATION: The normalization of CNS injury biomarkers in all individuals, regardless of previous disease severity or persisting neurological symptoms, indicates that post COVID-19 neurological sequelae are not accompanied by ongoing CNS injury. FUNDING: The Swedish State Support for Clinical Research, SciLifeLab Sweden, and the Knut and Alice Wallenberg Foundation have provided funding for this project.


Assuntos
Astrócitos/patologia , Astrócitos/virologia , COVID-19/patologia , COVID-19/virologia , SARS-CoV-2/patogenicidade , Idoso , Astrócitos/metabolismo , Biomarcadores/sangue , Biomarcadores/metabolismo , COVID-19/sangue , COVID-19/metabolismo , Progressão da Doença , Feminino , Seguimentos , Proteína Glial Fibrilar Ácida/metabolismo , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Proteínas de Neurofilamentos/metabolismo , Neurônios/metabolismo , Neurônios/patologia , Neurônios/virologia , Suécia
17.
Int J Mol Sci ; 22(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34360881

RESUMO

Intracerebral hemorrhage (ICH) is a major public health problem and devastating subtype of stroke with high morbidity and mortality. Notably, there is no effective treatment for ICH. Neuroinflammation, a pathological hallmark of ICH, contributes to both brain injury and repair and hence, it is regarded as a potential target for therapeutic intervention. Recent studies document that microRNAs, small non-coding RNA molecules, can regulate inflammatory brain response after ICH and are viable molecular targets to alter brain function. Therefore, there is an escalating interest in studying the role of microRNAs in the pathophysiology of ICH. Herein, we provide, for the first time, an overview of the microRNAs that play roles in ICH-induced neuroinflammation and identify the critical knowledge gap in the field, as it would help design future studies.


Assuntos
Hemorragia Cerebral/metabolismo , Encefalite/metabolismo , MicroRNAs/metabolismo , Transdução de Sinais/genética , Acidente Vascular Cerebral/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Lesões Encefálicas/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica , Humanos , Microglia/metabolismo , Microglia/patologia , Neurônios/metabolismo , Neurônios/patologia
18.
Int J Mol Sci ; 22(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34360906

RESUMO

The most common cause of dementia, especially in elderly people, is Alzheimer's disease (AD), with aging as its main risk factor. AD is a multifactorial neurodegenerative disease. There are several factors increasing the risk of AD development. One of the main features of Alzheimer's disease is impairment of brain energy. Hypometabolism caused by decreased glucose uptake is observed in specific areas of the AD-affected brain. Therefore, glucose hypometabolism and energy deficit are hallmarks of AD. There are several hypotheses that explain the role of glucose hypometabolism in AD, but data available on this subject are poor. Reduced transport of glucose into neurons may be related to decreased expression of glucose transporters in neurons and glia. On the other hand, glucose transporters may play a role as potential targets for the treatment of AD. Compounds such as antidiabetic drugs, agonists of SGLT1, insulin, siRNA and liposomes are suggested as therapeutics. Nevertheless, the suggested targets of therapy need further investigations.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Proteínas Facilitadoras de Transporte de Glucose/metabolismo , Glucose/metabolismo , Terapia de Alvo Molecular/métodos , Idoso , Envelhecimento/metabolismo , Animais , Encéfalo/metabolismo , Modelos Animais de Doenças , Humanos , Insulina/metabolismo , Insulina/uso terapêutico , Neuroglia/metabolismo , Neurônios/metabolismo , Fatores de Risco
19.
Am J Hum Genet ; 108(9): 1692-1709, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34375587

RESUMO

Kainate receptors (KARs) are glutamate-gated cation channels with diverse roles in the central nervous system. Bi-allelic loss of function of the KAR-encoding gene GRIK2 causes a nonsyndromic neurodevelopmental disorder (NDD) with intellectual disability and developmental delay as core features. The extent to which mono-allelic variants in GRIK2 also underlie NDDs is less understood because only a single individual has been reported previously. Here, we describe an additional eleven individuals with heterozygous de novo variants in GRIK2 causative for neurodevelopmental deficits that include intellectual disability. Five children harbored recurrent de novo variants (three encoding p.Thr660Lys and two p.Thr660Arg), and four children and one adult were homozygous for a previously reported variant (c.1969G>A [p.Ala657Thr]). Individuals with shared variants had some overlapping behavioral and neurological dysfunction, suggesting that the GRIK2 variants are likely pathogenic. Analogous mutations introduced into recombinant GluK2 KAR subunits at sites within the M3 transmembrane domain (encoding p.Ala657Thr, p.Thr660Lys, and p.Thr660Arg) and the M3-S2 linker domain (encoding p.Ile668Thr) had complex effects on functional properties and membrane localization of homomeric and heteromeric KARs. Both p.Thr660Lys and p.Thr660Arg mutant KARs exhibited markedly slowed gating kinetics, similar to p.Ala657Thr-containing receptors. Moreover, we observed emerging genotype-phenotype correlations, including the presence of severe epilepsy in individuals with the p.Thr660Lys variant and hypomyelination in individuals with either the p.Thr660Lys or p.Thr660Arg variant. Collectively, these results demonstrate that human GRIK2 variants predicted to alter channel function are causative for early childhood development disorders and further emphasize the importance of clarifying the role of KARs in early nervous system development.


Assuntos
Encéfalo/metabolismo , Deficiências do Desenvolvimento/genética , Epilepsia/genética , Deficiência Intelectual/genética , Mutação , Receptores de Ácido Caínico/genética , Adolescente , Adulto , Alelos , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Criança , Pré-Escolar , Deficiências do Desenvolvimento/diagnóstico por imagem , Deficiências do Desenvolvimento/metabolismo , Deficiências do Desenvolvimento/patologia , Epilepsia/diagnóstico por imagem , Epilepsia/metabolismo , Epilepsia/patologia , Potenciais Evocados/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Estudos de Associação Genética , Heterozigoto , Homozigoto , Humanos , Deficiência Intelectual/diagnóstico por imagem , Deficiência Intelectual/metabolismo , Deficiência Intelectual/patologia , Ativação do Canal Iônico , Masculino , Modelos Moleculares , Neurônios/metabolismo , Neurônios/patologia , Conformação Proteica , Receptores de Ácido Caínico/química , Receptores de Ácido Caínico/metabolismo
20.
Am J Hum Genet ; 108(9): 1647-1668, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34416157

RESUMO

Interpretation of the function of non-coding risk loci for neuropsychiatric disorders and brain-relevant traits via gene expression and alternative splicing quantitative trait locus (e/sQTL) analyses is generally performed in bulk post-mortem adult tissue. However, genetic risk loci are enriched in regulatory elements active during neocortical differentiation, and regulatory effects of risk variants may be masked by heterogeneity in bulk tissue. Here, we map e/sQTLs, and allele-specific expression in cultured cells representing two major developmental stages, primary human neural progenitors (n = 85) and their sorted neuronal progeny (n = 74), identifying numerous loci not detected in either bulk developing cortical wall or adult cortex. Using colocalization and genetic imputation via transcriptome-wide association, we uncover cell-type-specific regulatory mechanisms underlying risk for brain-relevant traits that are active during neocortical differentiation. Specifically, we identified a progenitor-specific eQTL for CENPW co-localized with common variant associations for cortical surface area and educational attainment.


Assuntos
Proteínas Cromossômicas não Histona/genética , Regulação da Expressão Gênica no Desenvolvimento , Neocórtex/metabolismo , Neurogênese/genética , Neurônios/metabolismo , Locos de Características Quantitativas , Alelos , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Diferenciação Celular , Cromatina/química , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Mapeamento Cromossômico , Escolaridade , Feminino , Feto , Predisposição Genética para Doença , Genoma Humano , Estudo de Associação Genômica Ampla , Humanos , Masculino , Neocórtex/citologia , Neocórtex/crescimento & desenvolvimento , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Neurônios/citologia , Neuroticismo , Doença de Parkinson/diagnóstico , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Cultura Primária de Células , Prognóstico , Esquizofrenia/diagnóstico , Esquizofrenia/genética , Esquizofrenia/metabolismo , Transcriptoma
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...