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Mutations and translocations within the COMPASS (complex of proteins associated with Set1) family of histone lysine methyltransferases are associated with a large number of human diseases, including cancer. Here we report that SET1B/COMPASS, which is essential for cell survival, surprisingly has a cytoplasmic variant. SET1B, but not its SET domain, is critical for maintaining cell viability, indicating a novel catalytic-independent role of SET1B/COMPASS. Loss of SET1B or its unique cytoplasmic-interacting protein, BOD1, leads to up-regulation of expression of numerous genes modulating fatty acid metabolism, including ADIPOR1 (adiponectin receptor 1), COX7C, SDC4, and COQ7 Our detailed molecular studies identify ADIPOR1 signaling, which is inactivated in both obesity and human cancers, as a key target of SET1B/COMPASS. Collectively, our study reveals a cytoplasmic function for a member of the COMPASS family, which could be harnessed for therapeutic regulation of signaling in human diseases, including cancer.
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Sistema Enzimático do Citocromo P-450/fisiologia , Histona-Lisina N-Metiltransferase/fisiologia , Neoplasias de Mama Triplo Negativas/metabolismo , Animais , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular , Sistema Enzimático do Citocromo P-450/química , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Citoplasma/enzimologia , Citoplasma/metabolismo , Histona-Lisina N-Metiltransferase/química , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Células MCF-7 , Camundongos , Camundongos Nus , Domínios PR-SET , Subunidades Proteicas/metabolismo , Receptores de Adiponectina/metabolismo , Transdução de Sinais , Neoplasias de Mama Triplo Negativas/etiologia , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologiaRESUMO
Aiming at the problem of low accuracy of multi-scale seafloor target detection in side-scan sonar images with high noise and complex background texture, a model for multi-scale target detection using the BES-YOLO network is proposed. First, an efficient multi-scale attention (EMA) mechanism is used in the backbone of the YOLOv8 network, and a bi-directional feature pyramid network (Bifpn) is introduced to merge the information of different scales, finally, a Shape_IoU loss function is introduced to continuously optimize the model and improve its accuracy. Before training, the dataset is preprocessed using 2D discrete wavelet decomposition and reconstruction to enhance the robustness of the network. The experimental results show that 92.4% of the mean average accuracy at IoU of 0.5 (mAP@0.5) and 67.7% of the mean average accuracy at IoU of 0.5 to 0.95 (mAP@0.5:0.95) are achieved using the BES-YOLO network, which is an increase of 5.3% and 4.4% compared to the YOLOv8n model. The research results can effectively improve the detection accuracy and efficiency of multi-scale targets in side-scan sonar images, which can be applied to AUVs and other underwater platforms to implement intelligent detection of undersea targets.
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Mutations on γ-secretase subunits are associated with neurologic diseases. Whereas the role of γ-secretase in neurogenesis has been intensively studied, little is known about its role in astrogliogenesis. Recent evidence has demonstrated that astrocytes can be generated from oligodendrocyte precursor cells (OPCs). However, it is not well understood what mechanism may control OPCs to differentiate into astrocytes. To address the above questions, we generated two independent lines of oligodendrocyte lineage-specific presenilin enhancer 2 (Pen-2) conditional KO mice. Both male and female mice were used. Here we demonstrate that conditional inactivation of Pen-2 mediated by Olig1-Cre or NG2-CreERT2 causes enhanced generation of astrocytes. Lineage-tracing experiments indicate that abnormally generated astrocytes are derived from Cre-expressing OPCs in the CNS in Pen-2 conditional KO mice. Mechanistic analysis reveals that deletion of Pen-2 inhibits the Notch signaling to upregulate signal transducer and activator of transcription 3, which triggers activation of GFAP to promote astrocyte differentiation. Together, these novel findings indicate that Pen-2 regulates the specification of astrocytes from OPCs through the signal transducer and activator of transcription 3 signaling.SIGNIFICANCE STATEMENT Astrocytes and oligodendrocyte (OLs) play critical roles in the brain. Recent evidence has demonstrated that astrocytes can be generated from OL precursor cells (OPCs). However, it remains poorly understood what mechanism governs the differentiation of OPCs into astrocytes. In this study, we took advantage of OL lineage cells specific presenilin enhancer 2 (Pen-2) conditional KO mice. We show that deletion of Pen-2 leads to dramatically enhanced astrocyte differentiation from OPCs in the CNS. Mechanistic analysis reveals that deletion of Pen-2 inhibits Hes1 and activates signal transducer and activator of transcription 3 to trigger GFAP activation which promotes astrocyte differentiation. Overall, this study identifies a novel function of Pen-2 in astrogliogenesis from OPCs.
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Secretases da Proteína Precursora do Amiloide/metabolismo , Astrócitos/citologia , Neurogênese/fisiologia , Células Precursoras de Oligodendrócitos/citologia , Animais , Diferenciação Celular/fisiologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
Synaptic plasticity is the neural basis of physiological processes involved in learning and memory. Tripartite motif-containing 32 (TRIM32) has been found to play many important roles in the brain such as neural stem cell proliferation, neurogenesis, inhibition of nerve proliferation, and apoptosis. TRIM32 has been linked to several nervous system diseases including autism spectrum disorder, depression, anxiety, and Alzheimer's disease. However, the role of TRIM32 in regulating the mechanism of synaptic plasticity is still unknown. Our electrophysiological studies using hippocampal slices revealed that long-term potentiation of CA1 synapses was impaired in TRIM32 deficient (KO) mice. Further research found that dendritic spines density, AMPA receptors, and synaptic plasticity-related proteins were also reduced. NMDA receptors were upregulated whereas GABA receptors were downregulated in TRIM32 deficient mice, explaining the imbalance in excitatory and inhibitory neurotransmission. This caused overexcitation leading to decreased neuronal numbers in the hippocampus and cortex. In summary, this study provides this maiden evidence on the synaptic plasticity changes of TRIM32 deficiency in the brain and proposes that TRIM32 relates the notch signaling pathway and its related mechanisms contribute to this deficit.
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Encéfalo/fisiologia , Plasticidade Neuronal/fisiologia , Receptores Notch/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Potenciais Pós-Sinápticos Excitadores/fisiologia , Masculino , Camundongos , Camundongos Knockout , Neurônios/fisiologiaRESUMO
Mammalian target of rapamycin (mTOR) signaling plays essential roles in brain development. Hyperactive mTOR is an essential pathological mechanism in autism spectrum disorder (ASD). Here, we show that tripartite motif protein 32 (TRIM32), as a maintainer of mTOR activity through promoting the proteasomal degradation of G protein signaling protein 10 (RGS10), regulates the proliferation of medial/lateral ganglionic eminence (M/LGE) progenitors. Deficiency of TRIM32 results in an impaired generation of GABAergic interneurons and autism-like behaviors in mice, concomitant with an elevated autophagy, which can be rescued by treatment embryonically with 3BDO, an mTOR activator. Transplantation of M/LGE progenitors or treatment postnatally with clonazepam, an agonist of the GABAA receptor, rescues the hyperexcitability and the autistic behaviors of TRIM32-/- mice, indicating a causal contribution of GABAergic disinhibition. Thus, the present study suggests a novel mechanism for ASD etiology in that TRIM32 deficiency-caused hypoactive mTOR, which is linked to an elevated autophagy, leads to autism-like behaviors via impairing generation of GABAergic interneurons. TRIM32-/- mouse is a novel autism model mouse.
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Transtorno Autístico/genética , Proliferação de Células/genética , Neurônios GABAérgicos/metabolismo , Interneurônios/metabolismo , Células-Tronco Neurais/metabolismo , Neurogênese/genética , Serina-Treonina Quinases TOR/metabolismo , Ubiquitina-Proteína Ligases/genética , Animais , Transtorno Autístico/metabolismo , Autofagia/efeitos dos fármacos , Autofagia/genética , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Clonazepam/farmacologia , Agonistas de Receptores de GABA-A/farmacologia , Neurônios GABAérgicos/efeitos dos fármacos , Interneurônios/efeitos dos fármacos , Camundongos , Camundongos Knockout , Células-Tronco Neurais/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas RGS/metabolismoRESUMO
PURPOSE: Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related deaths with high recurrence after surgery due to a paucity of effective post-surgical adjuvant treatments. DC vaccines can activate multiple anti-tumor immune responses but have not been explored for post-surgery PDAC recurrence. Intraperitoneal (IP) delivery may allow increased DC vaccine dosage and migration to lymph nodes. Here, we investigated the role of prophylactic DC vaccination controlling PDAC tumor growth with IP delivery as an administration route for DC vaccination. METHODS: DC vaccines were generated using ex vivo differentiation and maturation of bone marrow-derived precursors. Twenty mice were divided into four groups (nâ¯=â¯5) and treated with DC vaccines, unpulsed mature DCs, Panc02 lysates or no treatment. After tumor induction, mice underwent three magnetic resonance imaging scans to track tumor growth. Apparent diffusion coefficient (ADC), a quantitative magnetic resonance imaging measurement of tumor microstructure, was calculated. Survival was tracked. Tumor tissue was collected after death and stained with hematoxylin and eosin, Masson's trichrome, terminal deoxynucleotidyl transferase dUTP nick end labeling and anti-CD8 stains for histology. RESULTS: DC-vaccinated mice demonstrated stronger anti-tumor cytotoxicity compared with control groups on lactate dehydrogenase assay. DC vaccine mice also demonstrated decreased tumor volume, prolonged survival and increased ΔADC compared with control groups. On histology, the DC vaccine group had increased apoptosis, increased CD8+ T cells and decreased collagen. ΔADC negatively correlated with % collagen in tumor tissues. DISCUSSION: Prophylactic DC vaccination may inhibit PDAC tumor growth during recurrence and prolong survival. ΔADC may be a potential imaging biomarker that correlates with tumor histological features.
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Vacinas Anticâncer/imunologia , Carcinoma Ductal Pancreático/terapia , Células Dendríticas/imunologia , Células Dendríticas/transplante , Neoplasias Pancreáticas/terapia , Adenocarcinoma/terapia , Animais , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Humanos , Linfonodos/citologia , Camundongos , Camundongos Endogâmicos C57BL , Recidiva Local de Neoplasia/prevenção & controle , Vacinação , Neoplasias PancreáticasRESUMO
Epilepsy is a long-term neurological disease characterized by convulsions that can be recurrent. It is mainly caused by an imbalance between excitation and inhibition in the central nervous system. Currently, the pathogenesis is still unclear, although it may be related to changes in ion channels, neurotransmitters and glial cells. In recent years, increasing attention has been paid to the role of autophagy in the development of epilepsy. This chapter focuses on the role of the mTOR pathway in epileptogenesis and the relationship between autophagy, glycogen metabolism and Lafora disease and discusses the potential role of autophagy as a target for the treatment of epilepsy.
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Autofagia , Epilepsia , Autofagia/efeitos dos fármacos , Epilepsia/terapia , Humanos , Doença de Lafora , ConvulsõesRESUMO
Neurodevelopmental diseases are a class of neurodevelopmental disorders characterized by cognitive impairment and behavioral abnormalities and are mainly manifested as developmental disorders of the brain and nervous system. The pathological mechanism is not fully understood and may be related to hereditary or environmental factors. The elevation of autophagy during neural development suggests that autophagy may be involved in the process of neurodevelopment. This chapter focuses on the important functions of autophagy in all aspects of neurodevelopment and the role and mechanism of autophagy in neurodevelopmental disorders, especially in autism spectrum disorder.
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Autofagia , Transtornos do Neurodesenvolvimento , Transtorno do Espectro Autista , Encéfalo/patologia , HumanosRESUMO
Purpose To test the hypothesis that biomarkers of fluorine 18 (18F) fluorodeoxyglucose (FDG) positron emission tomography (PET) can be used for the early detection of therapeutic response to irreversible electroporation (IRE) of liver tumor in a rodent liver tumor model. Materials and Methods The institutional animal care and use committee approved this study. Rats were inoculated with McA-RH7777 liver tumor cells in the left median and left lateral lobes. Tumors were allowed to grow for 7 days to reach a size typically at least 5 mm in longest diameter, as verified with magnetic resonance (MR) imaging. IRE electrodes were inserted, and eight 100-µsec, 2000-V pulses were applied to ablate the tumor tissue in the left median lobe. Tumor in the left lateral lobe served as a control in each animal. PET/computed tomography (CT) and MR imaging measurements were performed at baseline and 3 days after IRE for each animal. Additional MR imaging measurements were obtained 14 days after IRE. After 14-day follow-up MR imaging, rats were euthanized and tumors harvested for hematoxylin-eosin, CD34, and caspase-3 staining. Change in the maximum standardized uptake value (ΔSUVmax) was calculated 3 days after IRE. The maximum lesion diameter change (ΔDmax) was measured 14 days after IRE by using axial T2-weighted imaging. ΔSUVmax and ΔDmax were compared. The apoptosis index was calculated by using caspase-3-stained slices of apoptotic tumor cells. Pearson correlation coefficients were calculated to assess the relationship between ΔSUVmax at 3 days and ΔDmax (or apoptosis index) at 14 days after IRE treatment. Results ΔSUVmax, ΔDmax, and apoptosis index significantly differed between treated and untreated tumors (P < .001 for all). In treated tumors, there was a strong correlation between ΔSUVmax 3 days after IRE and ΔDmax 14 days after IRE (R = 0.66, P = .01) and between ΔSUVmax 3 days after IRE and apoptosis index 14 days after IRE (R = 0.57, P = .04). Conclusion 18F-FDG PET imaging biomarkers can be used for the early detection of therapeutic response to IRE treatment of liver tumors in a rodent model. © RSNA, 2017.
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Eletroporação/métodos , Fluordesoxiglucose F18 , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/terapia , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos , Animais , Biomarcadores/metabolismo , Modelos Animais de Doenças , Fígado/diagnóstico por imagem , Fígado/metabolismo , Neoplasias Hepáticas/diagnóstico por imagem , Ratos , Resultado do TratamentoRESUMO
The generation of layer-specific neurons and astrocytes by radial glial cells during development of the cerebral cortex follows a precise temporal sequence, which is regulated by intrinsic and extrinsic factors. The molecular mechanisms controlling the timely generation of layer-specific neurons and astrocytes remain not fully understood. In this study, we show that the adhesion molecule contactin-associated protein (Caspr), which is involved in the maintenance of the polarized domains of myelinated axons, is essential for the timing of generation of neurons and astrocytes in the developing mouse cerebral cortex. Caspr is expressed by radial glial cells, which are neural progenitor cells that generate both neurons and astrocytes. Absence of Caspr in neural progenitor cells delays the production cortical neurons and induces precocious formation of cortical astrocytes, without affecting the numbers of progenitor cells. At the molecular level, Caspr cooperates with the intracellular domain of Notch to repress transcription of the Notch effector Hes1. Suppression of Notch signaling via a Hes1 shRNA rescues the abnormal neurogenesis and astrogenesis in Caspr-deficient mice. These findings establish Caspr as a novel key regulator that controls the temporal specification of cell fate in radial glial cells of the developing cerebral cortex through Notch signaling.
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Moléculas de Adesão Celular Neuronais/genética , Córtex Cerebral/crescimento & desenvolvimento , Células-Tronco Neurais/citologia , Neurogênese/fisiologia , Transdução de Sinais , Animais , Astrócitos/metabolismo , Axônios/metabolismo , Diferenciação Celular/fisiologia , Células Ependimogliais/metabolismo , Camundongos Knockout , Neurônios/citologia , Receptores Notch/metabolismo , Transdução de Sinais/fisiologiaRESUMO
G protein-coupled receptor 50 (GPR50), a risk factor for major depressive disorder and bipolar affective disorder, is expressed in both the developmental and adult brain. However, the function of GPR50 in the brain remains unknown. We here show GPR50 is expressed by neural progenitor cells (NPCs) in the ventricular zone of embryonic brain. Knockdown of GPR50 with a small interference RNA (siRNA) decreased self-renewal and neuronal differentiation, but not glial differentiation of NPCs. Moreover, overexpression of either full-length GPR50 or the intracellular domain of GPR50, rather than the truncated GPR50 in which the intracellular domain is deleted in, increased neuronal differentiation, indicating that GPR50 promotes neuronal differentiation of NPCs in an intracellular domain-dependent manner. We further described that the transcriptional activity of the intracellular domain of notch on Hes1 gene was repressed by overexpression of GPR50. In addition, decreased levels of transcription factor 7-like 2 (TCF7L2) mRNA was observed in GPR50 siRNA-transfected NPCs, suggesting that knockdown of GPR50 impairs wnt/ß-catenin signaling. Moreover, the mRNA levels of neurogenin (Ngn) 1, Ngn2 and cyclin D1, the target genes of notch and wnt/ß-catenin signalings, in NPCs were reduced by knockdown of GPR50. Therefore, GPR50 promotes self-renewal and neuronal differentiation of NPCs possibly through regulation of notch and wnt/ß-catenin signalings.
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Células-Tronco Embrionárias/citologia , Proteínas do Tecido Nervoso/metabolismo , Células-Tronco Neurais/citologia , Neurogênese , Receptores Acoplados a Proteínas G/metabolismo , Receptores Notch/metabolismo , Via de Sinalização Wnt , Animais , Células Cultivadas , Células-Tronco Embrionárias/metabolismo , Expressão Gênica , Técnicas de Silenciamento de Genes , Camundongos , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/genética , Células-Tronco Neurais/metabolismo , Receptores Acoplados a Proteínas G/genética , beta Catenina/metabolismoRESUMO
Fluorescent chemosensors are often preferred for tracking toxic ions because of their non-destructive measurement and ease of use in environmental real samples and biosystems. Exploring high selectivity, great sensitivity, and biocompatible fluorophores with facile, accessible and dual-responsive features is currently highly demanding. A coumarin-based naphthol hydrazone Schiff base chemosensor, NaChro, is designed and synthesized in a two-step process to detect toxic metal ions with strong emission. Fluorescence spectra analysis demonstrates that the probe binds to Hg2+ and Pb2+ ions with a 1:1 and a 2:1 stoichiometry, respectively, with high sensitivity, short response time and minimal interference from other metal ions. The observed reversible turn-on reaction was attributed to the inhibition of C = N isomerization and excited-state intramolecular proton transfer (ESIPT) processes once the ions were introduced. The practical applications of NaChro are successfully addressed in paper strips, various water samples, HeLa cells and Zebrafish, demonstrating that the probe can detect and track Hg2+ and Pb2+ ions in environmental samples and biosystems.
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Chumbo , Mercúrio , Humanos , Animais , Bases de Schiff , Células HeLa , Peixe-Zebra , Mercúrio/análise , Íons , Cumarínicos , Corantes FluorescentesRESUMO
STUDY OBJECTIVES: Mounting evidence indicated the correlation between sleep and cerebral small vessel disease (CSVD). However, little is known about the exact causality between poor sleep and white matter injury, a typical signature of CSVD, as well as the underlying mechanisms. METHODS: Spontaneously hypertensive rats (SHR) and control Wistar Kyoto rats were subjected to sleep fragmentation (SF) for 16 weeks. The effects of chronic sleep disruption on the deep white matter and cognitive performance were observed. RESULTS: SHR were validated as a rat model for CSVD. Fragmented sleep induced strain-dependent white matter abnormalities, characterized by reduced myelin integrity, impaired oligodendrocytes precursor cells (OPC) maturation and pro-inflammatory microglial polarization. Partially reversible phenotypes of OPC and microglia were observed in parallel following sleep recovery. CONCLUSIONS: Long-term SF-induced pathological effects on the deep white matter in a rat model of CSVD. The pro-inflammatory microglial activation and the block of OPC maturation may be involved in the mechanisms linking sleep to white matter injury.
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Doenças de Pequenos Vasos Cerebrais , Substância Branca , Ratos , Animais , Privação do Sono , Ratos Endogâmicos SHR , Sono , Ratos Endogâmicos WKY , Doenças de Pequenos Vasos Cerebrais/complicações , Doenças de Pequenos Vasos Cerebrais/patologiaRESUMO
Alzheimer's disease (AD) is a devastating neurodegenerative disorder that leads to progressive cognitive decline and neuropathological changes. Pericytes, which are vessel mural cells on the basement membrane of capillaries, play a crucial role in regulating cerebrovascular functions and maintaining neurovascular unit integrity. Emerging research substantiates the involvement of pericytes in AD. This review provides a comprehensive overview of pericytes, including their structure, origin, and markers and various functions within the central nervous system. Emphatically, the review explores the intricate mechanisms through which pericytes contribute to AD, including their interactions with amyloid beta and apolipoprotein E, as well as various signaling pathways. The review also highlights potential for targeted pericyte therapy for AD, with a focus on stem cell therapy and drug treatments. Future research directions include the classification of pericyte subtypes, studies related to aging, and the role of pericytes in exosome-related mechanisms in AD pathology. In conclusion, this review consolidates current knowledge on the pivotal roles of pericytes in AD and their potential as therapeutic targets, providing valuable insights for future research and clinical interventions aimed at addressing the impact of AD on patients' lives.
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Doença de Alzheimer , Pericitos , Pericitos/patologia , Pericitos/metabolismo , Pericitos/fisiologia , Humanos , Doença de Alzheimer/terapia , Doença de Alzheimer/patologia , Doença de Alzheimer/metabolismo , Animais , Peptídeos beta-Amiloides/metabolismoRESUMO
Seipin is one key mediator of lipid metabolism that is highly expressed in adipose tissues as well as in the brain. Lack of Seipin gene, Bscl2, leads to not only severe lipid metabolic disorders but also cognitive impairments and motor disabilities. Myelin, composed mainly of lipids, facilitates nerve transmission and is important for motor coordination and learning. Whether Seipin deficiency-leaded defects in learning and motor coordination is underlined by lipid dysregulation and its consequent myelin abnormalities remains to be elucidated. In the present study, we verified the expression of Seipin in oligodendrocytes (OLs) and their precursors, oligodendrocyte precursor cells (OPCs), and demonstrated that Seipin deficiency compromised OPC differentiation, which led to decreased OL numbers, myelin protein, myelinated fiber proportion and thickness of myelin. Deficiency of Seipin resulted in impaired spatial cognition and motor coordination in mice. Mechanistically, Seipin deficiency suppressed sphingolipid metabolism-related genes in OPCs and caused morphological abnormalities in lipid droplets (LDs), which markedly impeded OPC differentiation. Importantly, rosiglitazone, one agonist of PPAR-gamma, substantially restored phenotypes resulting from Seipin deficiency, such as aberrant LDs, reduced sphingolipids, obstructed OPC differentiation, and neurobehavioral defects. Collectively, the present study elucidated how Seipin deficiency-induced lipid dysregulation leads to neurobehavioral deficits via impairing myelination, which may pave the way for developing novel intervention strategy for treating metabolism-involved neurological disorders.
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Diferenciação Celular , Disfunção Cognitiva , Subunidades gama da Proteína de Ligação ao GTP , Bainha de Mielina , Células Precursoras de Oligodendrócitos , Animais , Subunidades gama da Proteína de Ligação ao GTP/metabolismo , Subunidades gama da Proteína de Ligação ao GTP/genética , Camundongos , Células Precursoras de Oligodendrócitos/metabolismo , Bainha de Mielina/metabolismo , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/patologia , Disfunção Cognitiva/genética , Metabolismo dos Lipídeos , Oligodendroglia/metabolismo , Oligodendroglia/patologia , Camundongos Endogâmicos C57BL , PPAR gama/metabolismo , PPAR gama/genética , Camundongos Knockout , Masculino , Rosiglitazona/farmacologiaRESUMO
AIMS: Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive cognitive dysfunction and memory impairment. AD pathology involves protein acetylation. Previous studies have mainly focused on histone acetylation in AD, however, the roles of nonhistone acetylation in AD are less explored. METHODS: The protein acetylation and expression levels were detected by western blotting and co-immunoprecipitation. The stoichiometry of acetylation was measured by home-made and site-specific antibodies against acetylated-CaM (Ac-CaM) at K22, K95, and K116. Hippocampus-dependent learning and memory were evaluated by using the Morris water maze, novel object recognition, and contextual fear conditioning tests. RESULTS: We showed that calmodulin (CaM) acetylation is reduced in plasma of AD patients and mice. CaM acetylation and its target Ca2+ /CaM-dependent kinase II α (CaMKIIα) activity were severely impaired in AD mouse brain. The stoichiometry showed that Ac-K22, K95-CaM acetylation were decreased in AD patients and mice. Moreover, we screened and identified that lysine deacetylase 9 (HDAC9) was the main deacetylase for CaM. In addition, HDAC9 inhibition increased CaM acetylation and CaMKIIα activity, and hippocampus-dependent memory in AD mice. CONCLUSIONS: HDAC9-mediated CaM deacetylation induces memory impairment in AD, HDAC9, or CaM acetylation may become potential therapeutic targets for AD.
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Doença de Alzheimer , Doenças Neurodegenerativas , Camundongos , Humanos , Animais , Doença de Alzheimer/metabolismo , Calmodulina , Camundongos Transgênicos , Transtornos da Memória/etiologia , Hipocampo/metabolismo , Modelos Animais de Doenças , Histona Desacetilases/metabolismo , Proteínas Repressoras/metabolismoRESUMO
Parkinson's disease (PD) is a ubiquitous brain cell degeneration disease and presents a significant therapeutic challenge. By injecting 6-hydroxydopamine (6-OHDA) into the left medial forebrain bundle, rats were made to exhibit PD-like symptoms and treated by intranasal administration of a low-dose (2 × 105) or high-dose (1 × 106) human neural stem cells (hNSCs). Apomorphine-induced rotation test, stepping test, and open field test were implemented to evaluate the motor behavior and high-performance liquid chromatography was carried out to detect dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), serotonin, and 5-hydroxyindole-3-acetic acid in the striatum of rats. Animals injected with 6-OHDA showed significant motor function deficits and damaged dopaminergic system compared to the control group, which can be restored by hNSCs treatment. Treatment with hNSCs significantly increased the tyrosine hydroxylase-immunoreactive cell count in the substantia nigra of PD animals. Moreover, the levels of neurotransmitters exhibited a significant decline in the striatum tissue of animals injected with 6-OHDA when compared to that of the control group. However, transplantation of hNSCs significantly elevated the concentration of DA and DOPAC in the injured side of the striatum. Our study offered experimental evidence to support prospects of hNSCs for clinical application as a cell-based therapy for PD.
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Neurons rely heavily on high mitochondrial metabolism to provide sufficient energy for proper development. However, it remains unclear how neurons maintain high oxidative phosphorylation (OXPHOS) during development. Mitophagy plays a pivotal role in maintaining mitochondrial quality and quantity. We herein describe that G protein-coupled receptor 50 (GPR50) is a novel mitophagy receptor, which harbors the LC3-interacting region (LIR) and is required in mitophagy under stress conditions. Although it does not localize in mitochondria under normal culturing conditions, GPR50 is recruited to the depolarized mitochondrial membrane upon mitophagy stress, which marks the mitochondrial portion and recruits the assembling autophagosomes, eventually facilitating the mitochondrial fragments to be engulfed by the autophagosomes. Mutations Δ502-505 and T532A attenuate GPR50-mediated mitophagy by disrupting the binding of GPR50 to LC3 and the mitochondrial recruitment of GPR50. Deficiency of GPR50 causes the accumulation of damaged mitochondria and disrupts OXPHOS, resulting in insufficient ATP production and excessive ROS generation, eventually impairing neuronal development. GPR50-deficient mice exhibit impaired social recognition, which is rescued by prenatal treatment with mitoQ, a mitochondrially antioxidant. The present study identifies GPR50 as a novel mitophagy receptor that is required to maintain mitochondrial OXPHOS in developing neurons.
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Mitocôndrias , Mitofagia , Neurônios , Receptores Acoplados a Proteínas G , Animais , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Neurônios/metabolismo , Mitocôndrias/metabolismo , Camundongos , Humanos , Fosforilação Oxidativa , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Espécies Reativas de Oxigênio/metabolismo , Camundongos Knockout , NeurogêneseRESUMO
INTRODUCTION: Nav1.6 is closely related to the pathology of Alzheimer's Disease (AD), and astrocytes have recently been identified as a significant source of ß-amyloid (Aß). However, little is known about the connection between Nav1.6 and astrocyte-derived Aß. OBJECTIVE: This study explored the crucial role of Nav1.6 in mediated astrocyte-derived Aß in AD and knockdown astrocytic Nav1.6 alleviates AD progression by promoting autophagy and lysosome-APP fusion. METHODS: A mouse model for astrocytic Nav1.6 knockdown was constructed to study the effects of astrocytic Nav1.6 on amyloidosis. The role of astrocytic Nav1.6 on autophagy and lysosome-APP(amyloid precursor protein) fusion was used by transmission electron microscope, immunostaining, western blot and patch clamp. Glial cell activation was detected using immunostaining. Neuroplasticity and neural network were assessed using patch-clamp, Golgi stain and EEG recording. Behavioral experiments were performed to evaluate cognitive defects. RESULTS: Astrocytic Nav1.6 knockdown reduces amyloidosis, alleviates glial cell activation and morphological complexity, improves neuroplasticity and abnormal neural networks, as well as promotes learning and memory abilities in APP/PS1 mice. Astrocytic Nav1.6 knockdown reduces itself-derived Aß by promoting lysosome- APP fusion, which is related to attenuating reverse Na+-Ca2+ exchange current thus reducing intracellular Ca2+ to facilitate autophagic through AKT/mTOR/ULK pathway. CONCLUSION: Our findings unveil the crucial role of astrocyte-specific Nav1.6 in reducing astrocyte-derived Aß, highlighting its potential as a cell-specific target for modulating AD progression.
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A pyridine modified naphthol hydrazone Schiff base chemosensor, NaPy, was prepared in a two-step process to detect aluminum ion (Al3+) in different samples. The probe shows a turn-off emission response towards Al3+ at a 1:1 binding stoichiometry via intramolecular charge transfer (ICT) mechanism, as validated by density functional theory (DFT) calculations and a series of spectroscopic measurements. The response time is slightly over one minute with a limit of detection (LOD) value of 0.164 µM, demonstrating the great sensitivity of the probe. It is also found that NaPy exhibits high selectivity towards Al3+ and resists interference from seventeen other cations. Application investigations in paper strips, water samples and HeLa cells suggest that NaPy can be used as an efficient probe for sensing Al3+ in real environmental samples and biosystems.