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1.
J Neurosci ; 44(10)2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38238073

RESUMO

Experience-dependent gene expression reshapes neural circuits, permitting the learning of knowledge and skills. Most learning involves repetitive experiences during which neurons undergo multiple stages of functional and structural plasticity. Currently, the diversity of transcriptional responses underlying dynamic plasticity during repetition-based learning is poorly understood. To close this gap, we analyzed single-nucleus transcriptomes of L2/3 glutamatergic neurons of the primary motor cortex after 3 d motor skill training or home cage control in water-restricted male mice. "Train" and "control" neurons could be discriminated with high accuracy based on expression patterns of many genes, indicating that recent experience leaves a widespread transcriptional signature across L2/3 neurons. These discriminating genes exhibited divergent modes of coregulation, differentiating neurons into discrete clusters of transcriptional states. Several states showed gene expressions associated with activity-dependent plasticity. Some of these states were also prominent in the previously published reference, suggesting that they represent both spontaneous and task-related plasticity events. Markedly, however, two states were unique to our dataset. The first state, further enriched by motor training, showed gene expression suggestive of late-stage plasticity with repeated activation, which is suitable for expected emergent neuronal ensembles that stably retain motor learning. The second state, equally found in both train and control mice, showed elevated levels of metabolic pathways and norepinephrine sensitivity, suggesting a response to common experiences specific to our experimental conditions, such as water restriction or circadian rhythm. Together, we uncovered divergent transcriptional responses across L2/3 neurons, each potentially linked with distinct features of repetition-based motor learning such as plasticity, memory, and motivation.


Assuntos
Aprendizagem , Plasticidade Neuronal , Masculino , Camundongos , Animais , Plasticidade Neuronal/genética , Aprendizagem/fisiologia , Neurônios/fisiologia , Destreza Motora/fisiologia , Água/metabolismo
2.
BMC Ophthalmol ; 23(1): 331, 2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37474921

RESUMO

BACKGROUND: To evaluate the effect of room air and sulfur hexafluoride (SF6) gas in idiopathic macular hole(MH)surgery. METHODS: Retrospective, interventional, and comparative study. 238 eyes with the idiopathic macular hole that underwent pars plana vitrectomy, internal limiting membrane peeling, fluid-air exchange, and 20% SF6 (SF6 group:125 eyes) or room air tamponade (air group: 113 eyes) were reviewed. The primary outcome measure was the closure rate of primary surgery. RESULTS: The baseline characteristics of the SF6 group and air group were comparable except for the hole size (479.90 ± 204.48 vs. 429.38 ± 174.63 µm, P = 0.043). The anatomical closure rate was 92.8% (116 / 125) with the SF6 group and 76.1% (86 / 113) with the air group (P < 0.001). A cut-off value of MH size to predict primary anatomical closure was 520 µm, which is based on the lower limit of 95% confidential interval of the MH size among the unclosed patients in the air group. There was no significant difference in anatomical closure rates between SF6 and air group (98.7% vs. 91.9%, P = 0.051) for MH ≤ 520 µm, whereas a significantly lower anatomical closure rate was shown in the air group than SF6 group (46.2% vs. 84.0%, P < 0.001) for MH > 520 µm. CONCLUSION: SF6 exhibited more effectiveness than air to achieve a good anatomical outcome for its longer tamponade when MH > 520 µm.


Assuntos
Perfurações Retinianas , Humanos , Perfurações Retinianas/cirurgia , Estudos Retrospectivos , Hexafluoreto de Enxofre , Vitrectomia , Acuidade Visual
3.
J Neurosci ; 41(19): 4160-4168, 2021 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-33893217

RESUMO

The brain functions through coordinated activity among distributed regions. Wide-field calcium imaging, combined with improved genetically encoded calcium indicators, allows sufficient signal-to-noise ratio and spatiotemporal resolution to afford a unique opportunity to capture cortex-wide dynamics on a moment-by-moment basis in behaving animals. Recent applications of this approach have been uncovering cortical dynamics at unprecedented scales during various cognitive processes, ranging from relatively simple sensorimotor integration to more complex decision-making tasks. In this review, we will highlight recent scientific advances enabled by wide-field calcium imaging in behaving mice. We then summarize several technical considerations and future opportunities for wide-field imaging to uncover large-scale circuit dynamics.


Assuntos
Cálcio , Córtex Cerebral/diagnóstico por imagem , Neuroimagem/métodos , Animais , Humanos
4.
Compr Rev Food Sci Food Saf ; 20(1): 289-331, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33443799

RESUMO

Meat quality plays an important role in the purchase decision of consumers, affecting producers and retailers. The formation mechanisms determining meat quality are intricate, as several endogenous and exogenous factors contribute during antemortem and postmortem periods. Abundant research has been performed on meat quality; however, unexpected variation in meat quality remains an issue in the meat industry. Protein posttranslational modifications (PTMs) regulate structures and functions of proteins in living tissues, and recent reports confirmed their importance in meat quality. The objective of this review was to provide a summary of the research on the effects of PTMs on meat quality. The effects of four common PTMs, namely, protein phosphorylation, acetylation, S-nitrosylation, and ubiquitination, on meat quality were discussed, with emphasis on the effects of protein phosphorylation on meat tenderness, color, and water holding capacity. The mechanisms and factors that may affect the function of protein phosphorylation are also discussed. The current research confirms that meat quality traits are regulated by multiple PTMs. Cross talk between different PTMs and interactions of PTMs with postmortem biochemical processes need to be explored to improve our understanding on factors affecting meat quality.


Assuntos
Processamento de Proteína Pós-Traducional , Proteínas , Acetilação , Carne , Fosforilação , Proteínas/metabolismo
5.
Exp Eye Res ; 193: 107972, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32059975

RESUMO

Autophagy plays critical roles in various ocular diseases, including age-related macular degeneration (AMD). Tie2-expressing macrophages (TEMs) play crucial roles in angiogenesis. To investigate the role of TEMs and autophagy in the development of AMD, we employed macrophage-specific Tie2 knockout mice and used a laser-induced choroidal neovascularization (CNV). The results showed that TEMs can promote CNV formation by up-regulating the level of autophagy. These results were further verified by in vitro cell experiments that peritoneal macrophages from Tie2 knockout mice can inhibit the expression of autophagy-related factors and inhibit the expression of angiogenic factor of VEGF by activating AMPK signaling pathway. Our results suggest that TEMs and macrophage Tie2 signal mediated-autophagy play critical role in experimental CNV, and they may be novel preventive targets for AMD treatment.


Assuntos
Neovascularização de Coroide/genética , Regulação da Expressão Gênica , Macrófagos/patologia , Receptor TIE-2/genética , Animais , Autofagia , Células Cultivadas , Neovascularização de Coroide/metabolismo , Neovascularização de Coroide/patologia , Modelos Animais de Doenças , Lasers/efeitos adversos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor TIE-2/biossíntese , Transdução de Sinais
6.
J Sci Food Agric ; 100(2): 551-559, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31587285

RESUMO

BACKGROUND: Phosphorylation is one of the most important post-translational modifications. Currently, many postmortem protein phosphorylation studies in muscle have been related to meat quality such as tenderness and color stability. However, the effects of various storage temperatures (25, 15, 4 and -1.5 °C) on the phosphorylation level of protein are poorly understood. Changes in the protein phosphorylation levels in postmortem ovine muscle at various storage temperatures were determined in this study. RESULTS: The obtained data showed that pH decline rate was significantly inhibited at -1.5 °C from 12 h to 7 days postmortem (P < 0.05). The ATP consumption rate was higher at 25 °C than that at other three temperatures (P < 0.05). Analysis of the temperature, pH and ATP content revealed that the ATP content was related to the phosphorylation levels of individual protein bands. Phosphorylated myofibrillar and sarcoplasmic proteins, such as myosin binding protein C, troponin T3, myosin light chain 1, glucose-6-phosphate isomerase and pyruvate kinase, were mainly involved in glycolysis and muscle contraction. CONCLUSION: The global and specific protein phosphorylation levels can be influenced by the postmortem storage temperature of muscle. Phosphorylation of proteins was correlated with glycolysis and muscle contraction. Certain phosphorylated proteins, such as heat shock proteins, require further study to clarify their effects on meat traits. © 2019 Society of Chemical Industry.


Assuntos
Armazenamento de Alimentos/métodos , Carne/análise , Proteínas Musculares/química , Músculo Esquelético/química , Animais , Armazenamento de Alimentos/instrumentação , Glicólise , Fosforilação , Mudanças Depois da Morte , Ovinos , Temperatura
7.
Adv Funct Mater ; 28(31)2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34084100

RESUMO

The last decades have witnessed substantial progress in optical technologies revolutionizing our ability to record and manipulate neural activity in genetically modified animal models. Meanwhile, human studies mostly rely on electrophysiological recordings of cortical potentials, which cannot be inferred from optical recordings, leading to a gap between our understanding of dynamics of microscale populations and brain-scale neural activity. By enabling concurrent integration of electrical and optical modalities, transparent graphene microelectrodes can close this gap. However, the high impedance of graphene constitutes a big challenge towards the widespread use of this technology. Here, we experimentally demonstrate that this high impedance of graphene microelectrodes is fundamentally limited by quantum capacitance. We overcome this quantum capacitance limit by creating a parallel conduction path using platinum nanoparticles. We achieve a 100 times reduction in graphene electrode impedance, while maintaining the high optical transparency crucial for deep 2-photon microscopy. Using a transgenic mouse model, we demonstrate simultaneous electrical recording of cortical activity with high fidelity while imaging calcium signals at various cortical depths right beneath the transparent microelectrodes. Multimodal analysis of Ca2+ spikes and cortical surface potentials offers unique opportunities to bridge our understanding of cellular dynamics and brain-scale neural activity.

8.
Biochem Biophys Res Commun ; 469(4): 903-10, 2016 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-26721440

RESUMO

pNO40/PS1D, a novel nucleolar protein, has been characterized as a core protein of eukaryotic 60S ribosome and at least two splicing forms of pNO40 mRNAs with alternative starting sites have been identified. Through production of knockout (ko) mice with either exon 2 (△E2), exon 4 (△E4) or △E2+E4 targeted disruption we identified a cryptic splicing product occurring in the ko tissues examined which in general cannot be observed in regular RT-PCR detection of wild-type (wt) animals. Among ko animals, △E4 null embryos exhibited prominent senescence-associated ß-galactosidase (SA-ß-gal) staining, a marker for senescent cells, in notochord, forelimbs and heart while bone marrow-derived mesenchymal stem cells (MSCs) from △E4 null mice developed accelerated aging and osteogenic differentiation defects compared to those from wt and other isoform mutant mice. Examination of the causal relationship between pNO40 deficiency and MSC-accelerated aging revealed △E4 null disruption in MSCs elicits high levels of ROS and elevated expression levels of p16 and Rb but not p53. Further analysis with iTraq identified CYP1B1, a component of the cytochrome p450 system, as a potential molecule mediating ROS generation in pNO40 deficient MSCs. We herein established a mouse model of MSC aging through pNO40-targeted depletion and demonstrated the effects of loss of pNO40 on bone homeostasis.


Assuntos
Senescência Celular/fisiologia , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Proteínas Nucleares/metabolismo , Osteoblastos/citologia , Osteogênese/fisiologia , Animais , Diferenciação Celular/fisiologia , Células Cultivadas , Citocromo P-450 CYP1B1/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Nucleares/genética , Osteoblastos/fisiologia , Espécies Reativas de Oxigênio/metabolismo
9.
Platelets ; 26(3): 243-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24750122

RESUMO

Primary immune thrombocytopenia (ITP) is an autoimmune disease with many immune dysfunctions, including over-proliferation and apoptosis resistance of auto-reactive lymphocytes. This study aimed to determine the effects of interleukin (IL)-7 on the cytokine production and survival of peripheral blood mononuclear cells and bone marrow mononuclear cells from ITP patients. We found that the plasma IL-7 levels in peripheral blood from ITP patients were lower than that of the normal controls, and it had positive correlation with platelet counts. However, the levels of IL-7 did not change in bone marrow serum of ITP patients compared with that of normal controls. The result of further stimulation experiments in vitro showed that IL-7 up-regulated the apoptosis of autologous platelets, promoted the proliferation and secretion of interferon-γ, tumor necrosis factor-α as well as IL-10 of lymphocyte both from peripheral blood and bone marrow. As the role of IL-7 in apoptosis-resistance and stimulation of pro-inflammatory cytokines, we speculated that decreased IL-7 in peripheral blood, maybe, is a consequence of the negative feedback of the pro-inflammatory function in ITP patients.


Assuntos
Mediadores da Inflamação/sangue , Interleucina-7/sangue , Púrpura Trombocitopênica Idiopática/sangue , Adolescente , Adulto , Idoso , Apoptose/efeitos dos fármacos , Plaquetas/efeitos dos fármacos , Estudos de Casos e Controles , Criança , Pré-Escolar , Citocinas/sangue , Feminino , Humanos , Mediadores da Inflamação/farmacologia , Interleucina-7/farmacologia , Linfócitos/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Adulto Jovem
10.
J Neurosci ; 33(19): 8423-41, 2013 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-23658180

RESUMO

Profound synapse loss is one of the major pathological hallmarks associated with Alzheimer's disease (AD) and might underlie memory impairment. Our previous work demonstrated that the magnesium ion is a critical factor in controlling synapse density/plasticity. Here, we investigated whether elevation of brain magnesium by the use of a recently developed compound, magnesium-l-threonate (MgT), can ameliorate the AD-like pathologies and cognitive deficits in the APPswe/PS1dE9 mice, a transgenic (Tg) mouse model of AD. MgT treatment reduced Aß plaque and prevented synapse loss and memory decline in the Tg mice. Strikingly, MgT treatment was effective even when given to the mice at the end stage of their AD-like pathological progression. To explore how elevation of brain magnesium ameliorates the AD-like pathologies in the brains of Tg mice, we studied molecules critical for APP metabolism and signaling pathways implicated in synaptic plasticity/density. In the Tg mice, the NMDAR/CREB/BDNF signaling was downregulated, whereas calpain/calcineurin/Cdk5 neurodegenerative signaling and ß-secretase (BACE1) expression were upregulated. MgT treatment prevented the impairment of these signaling pathways, stabilized BACE1 expression, and reduced soluble APPß and ß-C-terminal fragments in the Tg mice. At the molecular level, elevation of extracellular magnesium prevented the high-Aß-induced reductions in synaptic NMDARs by preventing calcineurin overactivation in hippocampal slices. Correlation studies suggested that the protection of NMDAR signaling might underlie the stabilization of BACE1 expression. Our results suggest that elevation of brain magnesium exerts substantial synaptoprotective effects in a mouse model of AD and may have therapeutic potential for treating AD in humans.


Assuntos
Doença de Alzheimer/complicações , Doença de Alzheimer/patologia , Encéfalo/metabolismo , Transtornos Cognitivos/etiologia , Magnésio/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Sinapses/patologia , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Precursor de Proteína beta-Amiloide/genética , Análise de Variância , Animais , Peso Corporal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Butiratos/farmacologia , Butiratos/uso terapêutico , Transtornos Cognitivos/prevenção & controle , Modelos Animais de Doenças , Comportamento Exploratório/efeitos dos fármacos , Glutamato Descarboxilase/metabolismo , Humanos , Magnésio/uso terapêutico , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Camundongos Transgênicos , Microscopia Eletrônica de Transmissão , Mutação/genética , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Técnicas de Patch-Clamp , Fragmentos de Peptídeos/líquido cefalorraquidiano , Presenilina-1/genética , Terminações Pré-Sinápticas/patologia , Terminações Pré-Sinápticas/ultraestrutura , Tempo de Reação/efeitos dos fármacos , Sinapses/efeitos dos fármacos , Sinapses/ultraestrutura , Distribuição Tecidual , Proteínas Vesiculares de Transporte de Acetilcolina/metabolismo
11.
Int J Biol Macromol ; 257(Pt 2): 128567, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38061521

RESUMO

The study investigated the different effects between protein phosphorylation and acetylation on glycolytic enzyme activity and myofibrillar protein degradation. Lamb longissimus thoracis lumborum muscles were homogenized and then inhibitors were added for incubation at 4 °C. Phosphatase inhibitor was added to produce a high phosphorylation level (PI group) and lysine deacetylase inhibitor was added to produce a high acetylation level (DI group). The lactate and ATP content in the PI group was inhibited compared with that in the DI group (P < 0.05). Phosphofructokinase (PFK) activity was negatively related with the phosphorylation level and was positively related with the acetylation level in the DI group (P < 0.05). The degradation of troponin T and desmin of the DI group were restrained when compared to that in the PI group (P < 0.05). Compared with initial PFK and desmin, the simulation of phosphorylation and acetylation of PFK and desmin showed different electrostatic potential at the surface and a more unstable structure. The phosphorylation level of the DI group was increased, suggesting that the changes of protein acetylation altered protein phosphorylation. In conclusion, compared with protein phosphorylation, protein acetylation had a greater effect on promoting glycolysis and inhibiting protein degradation.


Assuntos
Glicólise , Músculo Esquelético , Animais , Ovinos , Proteólise , Fosforilação , Acetilação , Desmina/análise , Desmina/metabolismo , Músculo Esquelético/metabolismo , Carne/análise
12.
Foods ; 13(11)2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38890876

RESUMO

cAMP-dependent protein kinase (PKA) activity regulates protein phosphorylation, with Na+ playing a crucial role in PKA activity. The aim of this study was to investigate the effects of different Na+ concentrations on PKA activity and protein phosphorylation level in postmortem muscle. The study consisted of two experiments: (1) NaCl of 0, 20, 100, 200 and 400 mM was added to a muscle homogenate incubation model to analyze the effect of Na+ concentration on PKA activity, and (2) the same concentrations were added to pure PKA in vitro incubation models at 4 °C to verify the effect of Na+ on PKA activity. The PKA activity of the muscle homogenate model increased with storage time in groups with different Na+ concentrations. High concentrations of Na+ inhibited sarcoplasmic protein phosphorylation. The PKA activity at 24 h of storage and the sarcoplasmic protein phosphorylation level at 12 h of storage in the group with 200 mM Na+ was lower than that of the other groups. After 1 h incubation, the PKA activity of samples in the 200 mM Na+ group was inhibited and lower than that in the other Na+ groups in the in vitro incubation model. These results suggest that the Na+ concentration at 200 mM could better inhibit PKA activity. This study provided valuable insights for enhancing curing efficiency and improving meat quality.

13.
Nat Nanotechnol ; 19(4): 504-513, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38212523

RESUMO

Optically transparent neural microelectrodes have facilitated simultaneous electrophysiological recordings from the brain surface with the optical imaging and stimulation of neural activity. A remaining challenge is to scale down the electrode dimensions to the single-cell size and increase the density to record neural activity with high spatial resolution across large areas to capture nonlinear neural dynamics. Here we developed transparent graphene microelectrodes with ultrasmall openings and a large, transparent recording area without any gold extensions in the field of view with high-density microelectrode arrays up to 256 channels. We used platinum nanoparticles to overcome the quantum capacitance limit of graphene and to scale down the microelectrode diameter to 20 µm. An interlayer-doped double-layer graphene was introduced to prevent open-circuit failures. We conducted multimodal experiments, combining the recordings of cortical potentials of microelectrode arrays with two-photon calcium imaging of the mouse visual cortex. Our results revealed that visually evoked responses are spatially localized for high-frequency bands, particularly for the multiunit activity band. The multiunit activity power was found to be correlated with cellular calcium activity. Leveraging this, we employed dimensionality reduction techniques and neural networks to demonstrate that single-cell and average calcium activities can be decoded from surface potentials recorded by high-density transparent graphene arrays.


Assuntos
Grafite , Nanopartículas Metálicas , Camundongos , Animais , Cálcio , Eletrodos Implantados , Platina , Microeletrodos
14.
J Agric Food Chem ; 72(20): 11724-11732, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38718268

RESUMO

Protein post-translational modifications (PTMs) play an essential role in meat quality development. However, the effect of specific PTM sites on meat proteins has not been investigated yet. The characteristics of pyruvate kinase M (PKM) were found to exhibit a close correlation with final meat quality, and thus, serine 99 (S99) and lysine 137 (K137) in PKM were mutated to study their effect on PKM function. The structural and functional properties of five lamb PKM variants, including wild-type PKM (wtPKM), PKM_S99D (S99 phosphorylation), PKM_S99A (PKM S99 dephosphorylation), PKM_K137Q (PKM K137 acetylation), and PKM_K137R (PKM K137 deacetylation), were evaluated. The results showed that the secondary structure, tertiary structure, and polymer formation were affected among different PKM variants. In addition, the glycolytic activity of PKM_K137Q was decreased because of its weakened binding with phosphoenolpyruvate. In the PKM_K137R variant, the actin phosphorylation level exhibited a decrease, suggesting a low kinase activity of PKM_K137R. The results of molecular simulation showed a 42% reduction in the interface area between PKM_K137R and actin, in contrast to wtPKM and actin. These findings are significant for revealing the mechanism of how PTMs regulate PKM function and provide a theoretical foundation for the development of precise meat quality preservation technology.


Assuntos
Glicólise , Piruvato Quinase , Piruvato Quinase/metabolismo , Piruvato Quinase/genética , Piruvato Quinase/química , Fosforilação , Animais , Acetilação , Ovinos , Processamento de Proteína Pós-Traducional , Proteínas Quinases/metabolismo , Proteínas Quinases/genética , Proteínas Quinases/química , Carne/análise
15.
Curr Eye Res ; 48(1): 70-79, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36271834

RESUMO

PURPOSE: This study aimed to explore the effect of the Semaphorin3A (Sema3A)/Neuropilin-1 (Nrp-1) pathway on Müller cell activities and endoplasmic reticulum (ER) stress induced by high glucose (HG) in vitro. METHODS: The primary Müller cells of C57BL/6J mice were isolated and cultured in normal or high glucose medium. The expression of endogenous Sema3A and its coreceptor Nrp-1 was measured by Western blot. Müller cells were incubated with exogenous recombinant Sema3A protein or transfected with lentiviral vectors expressing small hairpin RNA (shRNA) to knock down the expression of endogenous Sema3A. The proliferation of Müller cells was detected by CCK-8 assay and EdU staining. The migratory ability was detected by the Transwell migration assay. The level of endoplasmic reticulum (ER) stress was analyzed through the detection of GRP78/BiP, IRE1α, phosphorylated IRE1αS724 (p-IRE1αS724), and the splicing rate of XBP1 (XBP1s/XBP1) by using immunofluorescence, Western blot or quantitative polymerase chain reaction (qPCR). RESULTS: HG induced the upregulation of endogenous Sema3A and Nrp-1 receptors in Müller cells. The expression of GRP78/BiP and IRE1α was upregulated by HG, with an increased splicing rate of XBP1. Exogenous Sema3A inhibited HG-induced Müller cell proliferation, migration, and GRP78/BiP-IRE1α-XBP1 axis activation. Knockdown of Sema3A promoted proliferation, migration, and ER stress induced by high glucose in Müller cells. CONCLUSION: Sema3A inhibited the increased proliferative and migratory activities induced by high glucose by attenuating ER stress in Müller cells.


Assuntos
Proteínas Serina-Treonina Quinases , Semaforina-3A , Animais , Camundongos , Apoptose , Chaperona BiP do Retículo Endoplasmático , Estresse do Retículo Endoplasmático , Endorribonucleases/metabolismo , Células Ependimogliais/metabolismo , Glucose/farmacologia , Camundongos Endogâmicos C57BL , Proteínas Serina-Treonina Quinases/metabolismo , RNA Interferente Pequeno , Semaforina-3A/farmacologia
16.
Food Chem ; 421: 135896, 2023 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-37098310

RESUMO

The aim of this study was to investigate the effects of chilling rate on phosphorylation and acetylation levels of the glycolytic enzymes in meat, including glycogen phosphorylase, phosphofructokinase, aldolase (ALDOA), triose-phosphate isomerase (TPI1), phosphoglycerate kinase, lactate dehydrogenase (LDH). The samples were assigned into three groups: Control, Chilling 1 and Chilling 2, corresponding to the chilling rates of 4.8 °C/h, 23.0 °C/h and 25.1 °C/h respectively. The contents of glycogen and ATP were significantly higher in samples from the chilling groups. The activity and phosphorylation level of the six enzymes were higher in samples at the chilling rate of 25.1 °C/h, while the acetylation level of ALDOA, TPI1 and LDH were inhibited. In brief, glycolysis was delayed and the activity of glycolytic enzymes were maintained at higher level by the changes of phosphorylation and acetylation levels at the chilling rates of 23.0 °C/h and 25.1 °C/h, which may partly explain why very fast chilling improves meat quality.


Assuntos
Frutose-Bifosfato Aldolase , Triose-Fosfato Isomerase , Fosforilação , Acetilação , Triose-Fosfato Isomerase/metabolismo , L-Lactato Desidrogenase/metabolismo , Carne , Glicólise
17.
Invest Ophthalmol Vis Sci ; 64(13): 41, 2023 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-37883094

RESUMO

Purpose: Proteopathy is believed to contribute to age-related macular degeneration (AMD). Much research indicates that AMD begins in the retinal pigment epithelium (RPE), which is associated with formation of extracellular drusen, a clinical hallmark of AMD. Human RPE produces a drusen-associated abnormal protein, the exon Ⅵ-skipping splice isoform of retinal G protein-coupled receptor (RGR-d). In this study, we investigate the detrimental effects of RGR-d on cultured cells and mouse retina. Methods: ARPE-19 cells were stably infected by lentivirus overexpressing RGR or RGR-d and were treated with MG132, sometimes combined with or without endoplasmic reticulum (ER) stress inducer, tunicamycin. RGR and RGR-d protein expression, degeneration pathway, and potential cytotoxicity were explored. Homozygous RGR-d mice aged 8 or 14 months were fed with a high-fat diet for 3 months and then subjected to ocular examination and histopathology experiments. Results: We confirm that RGR-d is proteotoxic under various conditions. In ARPE-19 cells, RGR-d is misfolded and almost completely degraded via the ubiquitin-proteasome system. Unlike normal RGR, RGR-d increases ER stress, triggers the unfolded protein response, and exerts potent cytotoxicity. Aged RGR-d mice manifest disrupted RPE cell integrity, apoptotic photoreceptors, choroidal deposition of complement C3, and CD86+CD32+ proinflammatory cell infiltration into retina and RPE-choroid. Furthermore, the AMD-like phenotype of RGR-d mice can be aggravated by a high-fat diet. Conclusions: Our study confirmed the pathogenicity of the RGR splice isoform and corroborated a significant role of proteopathy in AMD. These findings may contribute to greater comprehension of the multifactorial causes of AMD.


Assuntos
Proteínas do Olho , Degeneração Macular , Receptores Acoplados a Proteínas G , Animais , Humanos , Camundongos , Éxons , Degeneração Macular/genética , Opsinas , Isoformas de Proteínas , Retina , Receptores Acoplados a Proteínas G/genética , Proteínas do Olho/genética
18.
J Agric Food Chem ; 71(41): 15280-15286, 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37776280

RESUMO

Myofibrillar protein degradation is primarily related to meat tenderness through protein phosphorylation regulation. Pyruvate kinase M2 (PKM2), a glycolytic rate-limiting enzyme, is also regarded as a protein kinase to catalyze phosphorylation. The objective of this study was to investigate the relationship between myofibrillar protein degradation and phosphorylation induced by PKM2. Myofibrillar proteins were incubated with PKM2 at 4, 25, and 37 °C. The global phosphorylation level of myofibrillar proteins in the PKM2 group was significantly increased, but it was sensitive to temperature (P < 0.05). Compared with 4 and 25 °C, PKM2 significantly increased the myofibrillar protein phosphorylation level from 0.5 to 6 h at 37 °C (P < 0.05). In addition, the degradation of desmin and actin was inhibited after they were phosphorylated by PKM2 when incubated at 37 °C. These results demonstrate that phosphorylation of myofibrillar proteins catalyzed by PKM2 inhibited protein degradation and provided a possible pathway for meat tenderization through glycolytic enzyme regulation.


Assuntos
Actinas , Piruvato Quinase , Fosforilação , Proteólise , Piruvato Quinase/metabolismo , Actinas/metabolismo , Músculo Esquelético/metabolismo
19.
Adv Sci (Weinh) ; 10(33): e2302333, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37870175

RESUMO

Single-unit (SU) recording in nonhuman primates (NHPs) is indispensible in the quest of how the brain works, yet electrodes currently used for the NHP brain are limited in signal longevity, stability, and spatial coverage. Using new structural materials, microfabrication, and penetration techniques, we develop a mechanically robust ultraflexible, 1 µm thin electrode array (MERF) that enables pial penetration and high-density, large-scale, and chronic recording of neurons along both vertical and horizontal cortical axes in the nonhuman primate brain. Recording from three monkeys yields 2,913 SUs from 1,065 functional recording channels (up to 240 days), with some SUs tracked for up to 2 months. Recording from the primary visual cortex (V1) reveals that neurons with similar orientation preferences for visual stimuli exhibited higher spike correlation. Furthermore, simultaneously recorded neurons in different cortical layers of the primary motor cortex (M1) show preferential firing for hand movements of different directions. Finally, it is shown that a linear decoder trained with neuronal spiking activity across M1 layers during monkey's hand movements can be used to achieve on-line control of cursor movement. Thus, the MERF electrode array offers a new tool for basic neuroscience studies and brain-machine interface (BMI) applications in the primate brain.


Assuntos
Encéfalo , Primatas , Animais , Eletrodos , Análise de Célula Única
20.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 31(2): 489-494, 2023 Apr.
Artigo em Zh | MEDLINE | ID: mdl-37096524

RESUMO

OBJECTIVE: To screen better promoters and provide more powerful tools for basic research and gene therapy of hemophilia. METHODS: Bioinformatics methods were used to analyze the promoters expressing housekeeping genes with high abundance, so as to select potential candidate promoters. The GFP reporter gene vector was constructed, and the packaging efficiency of the novel promoter was investigated with EF1 α promoter as control, and the transcription and activities of the reporter gene were investigated too. The activity of the candidate promoter was investigated by loading F9 gene. RESULTS: The most potential RPS6 promoter was obtained by screening. There was no difference in lentiviral packaging between EF1 α-LV and RPS6-LV, and their virus titer were consistent. In 293T cells, the transduction efficiency and mean fluorescence intensity of RPS6pro-LV and EF1 αpro-LV were proportional to the lentiviral dose. The transfection efficiency of both promoters in different types of cells was in the following order: 293T>HEL>MSC; Compared with EF1 αpro-LV, RPS6pro-LV could obtain a higher fluorescence intensity in MSC cells, and RPS6pro-LV was more stable in long-term cultured HEL cells infected with two lentiviruses respectively. The results of RT-qPCR, Western blot and FIX activity (FIX∶C) detection of K562 cell culture supernatant showed that FIX expression in the EF1 α-F9 and RPS6-F9 groups was higher than that in the unloaded control group, and there was no significant difference in FIX expression between the EF1 α-F9 and RPS6-F9 groups. CONCLUSION: After screening and optimization, a promoter was obtained, which can be widely used for exogenous gene expression. The high stability and viability of the promoter were confirmed by long-term culture and active gene expression, which providing a powerful tool for basic research and clinical gene therapy of hemophilia.


Assuntos
Vetores Genéticos , Hemofilia A , Humanos , Transdução Genética , Hemofilia A/genética , Transfecção , Fatores de Coagulação Sanguínea/genética , Lentivirus/genética
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