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1.
Artigo em Inglês | MEDLINE | ID: mdl-38848727

RESUMO

A series of Fe-substituted Co2Sn1-xFexO4 (0 ≤ x ≤ 0.4) inverse spinel's oxides was synthesized using the solid-state reaction method. X-ray analysis reveals a single-phase cubic structure with the space group Fd3m. The transition temperature is shown to increase with a higher Fe concentration in the Co2Sn1-xFexO4 spinel oxide. The ac susceptibility at different frequencies also confirms a spin-glassy state at lower temperatures. The sample with Fe substitution (x = 0.2) exhibits a significant exchange bias effect when subjected to a constant temperature of ~10 K. The susceptibility at high temperatures, as calculated using Curie-Wise fitting, suggests that the system undergoes a shift from antiferromagnetic exchange (x < 0.2) to ferromagnetic exchange (x > 0.2).

2.
Proc Natl Acad Sci U S A ; 121(22): e2316176121, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38771878

RESUMO

The striato-nigral (Str-SN) circuit is composed of medium spiny neuronal projections that are mainly sent from the striatum to the midbrain substantial nigra (SN), which is essential for regulating motor behaviors. Dysfunction of the Str-SN circuitry may cause a series of motor disabilities that are associated with neurodegenerative disorders, such as Huntington's disease (HD). Although the etiology of HD is known as abnormally expanded CAG repeats of the huntingtin gene, treatment of HD remains tremendously challenging. One possible reason is the lack of effective HD model that resembles Str-SN circuitry deficits for pharmacological studies. Here, we first differentiated striatum-like organoids from human pluripotent stem cells (hPSCs), containing functional medium spiny neurons (MSNs). We then generated 3D Str-SN assembloids by assembling striatum-like organoids with midbrain SN-like organoids. With AAV-hSYN-GFP-mediated viral tracing, extensive MSN projections from the striatum to the SN are established, which formed synaptic connection with GABAergic neurons in SN organoids and showed the optically evoked inhibitory postsynaptic currents and electronic field potentials by labeling the striatum-like organoids with optogenetic virus. Furthermore, these Str-SN assembloids exhibited enhanced calcium activity compared to that of individual striatal organoids. Importantly, we further demonstrated the reciprocal projection defects in HD iPSC-derived assembloids, which could be ameliorated by treatment of brain-derived neurotrophic factor. Taken together, these findings suggest that Str-SN assembloids could be used for identifying MSN projection defects and could be applied as potential drug test platforms for HD.


Assuntos
Doença de Huntington , Organoides , Humanos , Doença de Huntington/patologia , Doença de Huntington/metabolismo , Organoides/patologia , Organoides/metabolismo , Substância Negra/patologia , Substância Negra/metabolismo , Corpo Estriado/patologia , Corpo Estriado/metabolismo , Neurônios/metabolismo , Neurônios/patologia , Diferenciação Celular , Neurônios GABAérgicos/metabolismo , Neurônios GABAérgicos/patologia , Células-Tronco Pluripotentes/metabolismo , Optogenética
3.
ACS Appl Mater Interfaces ; 16(9): 11506-11515, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38382476

RESUMO

Lithium metal batteries with high nickel ternary (LiNixCoyMn1-x-yO2, x ≥ 0.8) as the cathode hold the promise to meet the demand of next-generation high energy density batteries. However, the unsatisfactory stability of electrode-electrolyte interfaces limits their practical applications. In this work, N-methyl-N-trimethylsilyltrifluoroacetamide (NMTFA) is suggested as a new functional electrolyte additive to stabilize the Li∥LiNi0.9Co0.05Mn0.05O2 chemistry by forming robust and effective electrode-electrolyte interphases, namely the anode-electrolyte interphase (AEI, or conventionally called SEI) and cathode-electrolyte interphase (CEI). The NMTFA-derived SEI/CEI greatly enhances the battery performance that a capacity retention of 82.1% after 200 cycles at 1C charge/discharge is achieved, significantly higher than that without NMTFA addition (52.5%). Moreover, the NMTFA also improves the thermal stability of the electrolyte and inhibits the hydrolysis of LiPF6. This work provides new clues for the optimization of electrolyte formulation for lithium-high nickel batteries through modulating interfaces.

4.
Biotechnol J ; 19(1): e2300395, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38180295

RESUMO

The mammalian cell culture process is a key step in commercial therapeutic protein production and needs to be monitored and controlled due to its complexity. Raman spectroscopy has been reported for cell culture process monitoring by analysis of many important parameters. However, studies on in-line Raman monitoring of the cell culture process were mainly conducted on small or pilot scale. Developing in-line Raman analytical methods for commercial-scale cell culture process monitoring is more challenging. In this study, an in-line Raman analytical method was developed for monitoring glucose, lactate, and viable cell density (VCD) in the Chinese hamster ovary (CHO) cell culture process during commercial production of biosimilar adalimumab (1500 L). The influence of different Raman measurement channels was considered to determine whether to merge data from different channels for model development. Raman calibration models were developed and optimized, with minimum root mean square error of prediction of 0.22 g L-1 for glucose in the range of 1.66-3.53 g L-1 , 0.08 g L-1 for lactate in the range of 0.15-1.19 g L-1 , 0.31 E6 cells mL-1 for VCD in the range of 0.96-5.68 E6 cells mL-1 on test sets. The developed analytical method can be used for cell culture process monitoring during manufacturing and meets the analytical purpose of this study. Further, the influence of the number of batches used for model calibration on model performance was also studied to determine how many batches are needed basically for method development. The proposed Raman analytical method development strategy and considerations will be useful for monitoring of similar bioprocesses.


Assuntos
Reatores Biológicos , Técnicas de Cultura de Células , Cricetinae , Animais , Cricetulus , Células CHO , Técnicas de Cultura de Células/métodos , Ácido Láctico/metabolismo , Análise Espectral Raman/métodos , Glucose/metabolismo , Técnicas de Cultura Celular por Lotes/métodos
5.
Opt Express ; 31(25): 42125-42135, 2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-38087593

RESUMO

Space-division multiplexing (SDM) has been expected to support the continuous growth of transmission capacity. However, it suffers from high computation complexity that limits its physical implementations. In this paper, we propose and experimentally demonstrate a low-complexity MIMO equalization method to leverage the sparsity of weights and reduce the complexity by L1&L2-regularization in long-haul space-division multiplexing (SDM) systems. The L1-regularization finds the sparse solution of equalizer filters and substitutes it for optimal solution, reducing the complexity with performance degradation. On the other hand, the L2-regularization tends to produce a smoother estimation than L1 regularization and is therefore more robust to large variance. We conduct a 39.87-GBaud QPSK coherent optical transmission experiment based on a 4-core coupled-core fiber with the transmission distance from 1206-km to 7236-km. Comparisons on the equalization performance and computational complexity show that the sparse equalizer using L1&L2-regularization achieves a 30% reduction in complexity at the similar system performance, compared with the traditional time-domain MIMO.

6.
Biochim Biophys Acta Mol Cell Res ; 1870(6): 119487, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37211156

RESUMO

Mitochondrial protein homeostasis is fine-tuned by diverse physiological processes such as mitochondria-associated degradation (MAD), which is regulated by valosin-containing protein (VCP) and its cofactors. As a cofactor of VCP, the mutation of phospholipase A-2-activating protein (PLAA) is the genetic cause of PLAA-associated neurodevelopmental disorder (PLAAND). However, the physiological and pathological roles of PLAA in mitochondria remain unclear. Here, we demonstrate that PLAA partially associates with mitochondria. Deficiency in PLAA increases mitochondrial reactive oxygen species (ROS) production, reduces mitochondrial membrane potential, inhibits mitochondrial respiratory activity and causes excessive mitophagy. Mechanically, PLAA interacts with myeloid cell leukemia-1 (MCL1) and facilitates its retro-translocation and proteasome-dependent degradation. The upregulation of MCL1 promotes the oligomerization of NLR family member X1 (NLRX1) and activation of mitophagy. Whereas downregulating NLRX1 abolishes MCL1 induced mitophagy. In summary, our data identify PLAA as a novel mediator of mitophagy by regulating MCL1-NLRX1 axis. We propose mitophagy as a target for therapeutic intervention in PLAAND.


Assuntos
Mitocôndrias , Mitofagia , Mitofagia/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo
7.
Materials (Basel) ; 16(10)2023 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-37241492

RESUMO

Because of their extensive specific surface area, excellent charge transfer rate, superior chemical stability, low cost, and Earth abundance, nanostructured titanium dioxide (TiO2) arrays have been thoroughly explored during the past few decades. The synthesis methods for TiO2 nanoarrays, which mainly include hydrothermal/solvothermal processes, vapor-based approaches, templated growth, and top-down fabrication techniques, are summarized, and the mechanisms are also discussed. In order to improve their electrochemical performance, several attempts have been conducted to produce TiO2 nanoarrays with morphologies and sizes that show tremendous promise for energy storage. This paper provides an overview of current developments in the research of TiO2 nanostructured arrays. Initially, the morphological engineering of TiO2 materials is discussed, with an emphasis on the various synthetic techniques and associated chemical and physical characteristics. We then give a brief overview of the most recent uses of TiO2 nanoarrays in the manufacture of batteries and supercapacitors. This paper also highlights the emerging tendencies and difficulties of TiO2 nanoarrays in different applications.

8.
Micromachines (Basel) ; 14(2)2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36837934

RESUMO

In this study, the water-jet-guided laser (WJGL) method was used to cut Inconel 718 alloy with high temperature resistance. The effect of critical parameters of the water-jet-guided laser machining method on the cutting depth was studied by a Taguchi orthogonal experiment. Furthermore, the mathematical prediction model of cutting depth was established by the response surface method (RSM). The validation experiments showed that the mathematical model had a high predictive ability for cutting depth. The optimal cutting depth was obtained by model prediction, and the error was 5.5% compared with the experimental results. Compared with the traditional dry laser cutting, the water conducting laser method reduced the thermal damage and improved the cutting quality. This study provides a reference for the precision machining of Inconel 718 with a water-jet-guided laser.

9.
EMBO Mol Med ; 15(1): e16364, 2023 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-36373384

RESUMO

Major depressive disorder with suicide behavior (sMDD) is a server mood disorder, bringing tremendous burden to family and society. Although reduced gamma amino butyric acid (GABA) level has been observed in postmortem tissues of sMDD patients, the molecular mechanism by which GABA levels are altered remains elusive. In this study, we generated induced pluripotent stem cells (iPSC) from five sMDD patients and differentiated the iPSCs to GABAergic interneurons (GINs) and ventral forebrain organoids. sMDD GINs exhibited altered neuronal morphology and increased neural firing, as well as weakened calcium signaling propagation, compared with controls. Transcriptomic sequencing revealed that a decreased expression of serotoninergic receptor 2C (5-HT2C) may cause the defected neuronal activity in sMDD. Furthermore, targeting 5-HT2C receptor, using a small molecule agonist or genetic approach, restored neuronal activity deficits in sMDD GINs. Our findings provide a human cellular model for studying the molecular mechanisms and drug discoveries for sMDD.


Assuntos
Transtorno Depressivo Maior , Humanos , Transtorno Depressivo Maior/metabolismo , Interneurônios/metabolismo , Neurônios/metabolismo , Diferenciação Celular , Ácido gama-Aminobutírico/metabolismo
10.
Front Physiol ; 14: 1308777, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38162826

RESUMO

The Manila clam (Ruditapes philippinarum), as one of the shellfish living in the intertidal zone, is known for its strong ability to withstand air exposure. Sodium nitroprusside (SNP), a donor of nitric oxide (NO), has been shown to be useful for antioxidant and immune regulation in aquatic animals. In this study, an untargeted metabolomics (LC-MS/MS) technique was employed for the first time in Manila clam to analyze the metabolic and histological impacts after air exposure and the positive effects of SNP pretreatment. During air exposure, a significant increase in taurine, L-glutamate, and several polyunsaturated fatty acids in clams was detected, which indicates that clams may experience inflammatory reactions, oxidative stress, and an increase in blood ammonia content. When clams were exposed to SNP for 6 h, arginine, spermine, L-glutamic acid, and glutathione content were all upregulated, indicating that the SNP exposure induced NO production and improved antioxidant capacity in clams. When the clams were exposed to air after SNP pretreatment, there were no significant differences in the levels of taurine, L-glutamate, or aliphatic acids between the experimental and control groups. Gill tissue was more severely damaged in clams directly exposed to air than in those that experienced air exposure after SNP pretreatment, especially in clams exposed to air for a long time (72 h). Both metabolomics and tissue section structure indicated that SNP pretreatment decreased the stress responses caused by air exposure in R. philippinarum. These findings provided fresh insights and a theoretical foundation for understanding the tolerance to air exposure and physiological functions of SNP (or NO) in R. philippinarum.

11.
Materials (Basel) ; 15(21)2022 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-36363020

RESUMO

In order to improve the tribological properties of Ti-6Al-4V alloy and further broaden the application scope of titanium alloy materials in the industrial field, a preparation method of a waterjet-guided high-power laser processing surface microgroove was studied. In this paper, a multifocus coupling lens was innovatively designed to replace the spherical lens in the traditional waterjet-guided laser coupling device, which avoids the gas explosion phenomenon in the coupling of the high-power laser and waterjet, and realizes the high-quality coupling of the high-power laser and water beam fiber. Then, with the microgroove morphology as the response target, the single-factor test and response surface test of the water-guided laser processing microgroove were carried out. Based on the experimental results, an approximate mathematical model of the response surface between the process parameters and the microgroove topography target was constructed, and the quantitative relationship between the waterjet-guided laser processing parameters and the target response was studied. At the same time, the optimal combination of process parameters was obtained by multiobjective optimization, so as to effectively improve the microgroove morphology. This technology provides method guidance and a decision-making reference for subsequent waterjet-guided laser processing of titanium alloy surface functional microstructures.

12.
Micromachines (Basel) ; 13(9)2022 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-36143997

RESUMO

Due to the special manufacturing process of cobalt-chromium alloy cardiovascular stent tubes, there are serious surface defects in their inner walls, which affects the therapeutic effect after implantation. At the same time, the traditional processing technology cannot finish the inner wall of a cardiovascular stent tube. In light of the above problems, magnetic abrasive finishing (MAF) equipment for the inner wall of an ultra-fine and ultra-long cardiovascular stent tube is proposed, and MAF technology is used to improve the surface quality of its inner wall. High-performance spherical magnetic abrasive powders are used to finish the inner wall of a cobalt-chromium alloy cardiovascular stent tube with an inner diameter of 1.6 mm and an outer diameter of 1.8 mm. The effects of finishing time, tube rotational speed, feed speed of the magnetic pole, MAPs filling quantity, and MAP abrasive size on the surface roughness and material removal thickness of cobalt-chromium alloy cardiovascular stent tube are investigated. The results show that the surface roughness of the inner wall of the cobalt-chromium alloy cardiovascular stent decreases from 0.485 µm to 0.101 µm, and the material removal thickness of the defect layer is 4.3 µm. MAF technology is used to solve the problem of the poor surface quality of the inner walls of ultra-fine and ultra-long cobalt-chromium alloy cardiovascular stent tubes.

13.
Micromachines (Basel) ; 13(9)2022 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-36144028

RESUMO

In this study, a new method of ultrasonic high-frequency percussion (UH-FP) is proposed. Ultra-fine and ultra-long copper tube electrodes cannot be fabricated by traditional processing methods, and the copper tube electrodes fabricated by UH-FP can be used in the process of rotary EDM for microfine holes. The UH-FP setup has been established based on an ultrasonic device, a workpiece chucking and rotation device, and a workpiece reciprocating motion device. In this work, by studying the principle of ultrasonic processing, the processing principle and mechanism of ultra-fine and ultra-long copper tube electrode preparation by ultrasonic high-frequency percussion is proposed. The effects of processing parameters (i.e., rotational speed, feed rate, working gap, percussion amplitude) on surface roughness are evaluated quantitatively. Experimental results show that the proposed method could complete the core leach of the core-containing copper tube electrodes after drawing, while improving surface quality. Some surface defects such as cracks, scratches and folds were completed removed, further improving the mechanical performance of processed parts. The surface roughness (Ra) of 0.091 µm was obtained from the initial 0.46 µm under the optimal processing parameters of 800 rpm tube rotational speed, 200 mm/min platform feed speed, 0.13 mm machining gap, 0.15 mm percussion amplitude, and 32 min machining time. The method shows potential for manufacturing copper tube electrodes for a wide range of industrial applications.

14.
Materials (Basel) ; 15(14)2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35888357

RESUMO

In this study, laser-assisted machining experiments are carried out on silicon carbide (SiC) ceramic materials by a turning process, and laser power, cutting depth, rotational speed, and feed speed are selected as research factors. In order to improve the surface processing quality of laser-assisted turning of SiC ceramics and obtain the smallest surface roughness, the orthogonal method and response surface method are used to investigate the effect of various factors on surface roughness. The effect of various factors on surface roughness is evaluated by variance analysis, mean analysis, main effect diagram, 3D response surface, and corresponding contour diagram. The surface roughness prediction model is established based on the response surface method, and the prediction error is 4.1% with high accuracy. The experimental results show that laser power and cutting depth are the most significant factors affecting surface roughness, and rotational speed is a significant factor affecting surface roughness. Under the optimum process conditions, the smallest surface roughness Ra obtained by the response surface method is 0.294 µm, which is lower than 0.315 µm obtained by the orthogonal method, and the surface quality is higher. Therefore, the optimal process parameters of the response surface method can obtain the smallest surface roughness and higher surface quality in laser-assisted turning of SiC ceramics.

15.
Chem Sci ; 13(21): 6217-6223, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35733907

RESUMO

Electrochemical cytometry based on nano-tip microelectrodes was used to quantify the vesicular storage at the single-cell level in human neurons and midbrain organoids which acted as disease models of young-onset Parkinson's disease (YOPD). Human dopaminergic (DA) neurons and midbrain organoids were derived from an induced pluripotent stem cell line from one YOPD patient. We show a significant deficiency in vesicular catecholamine storage and a slower pore forming process on the surface of the microelectrode in the DA neurons derived from the YOPD patient. The upregulation of α-synuclein in both neurons and organoids derived from the YOPD patient is associated with vesicular storage dysfunction, revealing a correlation between the pathogenesis of YOPD and vesicular chemical storage deficiency, a novel chemical insight into the potential pathology of YOPD. Notably, efficacy evaluation and drug testing were performed with our platform to demonstrate that both amantadine, a clinical drug for Parkinson's disease (PD), and phorbol 12-myristate 13-acetate, an attractive candidate, ameliorate the dysfunction of vesicular storage in DA neurons derived from the YOPD patient. Our platform offers promising avenues for new drug discovery for PD and other neurodegenerative disorders.

16.
Artigo em Inglês | MEDLINE | ID: mdl-35753648

RESUMO

The cytotoxic effect and cell death were studied in loach fin cells in vitro after enrofloxacin (ENR) exposure. The semi-lethal concentration of ENR for loach cells was calculated as 1296.2 ± 3.11 mol/L (about 512.5 mg/L). Loss of cell viability, increase in vacuoles, disappearance of microvilli, and apoptotic bodies were evident in cells exposed to 400, 800, and 1200 µmol/L ENR. Besides, dose-dependent inhibitory effects on SOD, CAT, Na+-K+-ATPase, and Ca2+-ATPase activities were also observed in loach cells exposed to ENR. Quantitative gene expression results showed that ENR induced caspase-3- and caspase-8-mediated apoptosis as well as caspase-activated DNase in loach cells. The findings also indicated a role of JNK pathway in ENR-induced apoptosis in loach cells. Transcriptome sequencing results showed 10,016 differentially expressed genes in ENR vs. control groups, which were all enriched in "Molecular Function" process in GO term. Furthermore, 6763 genes were enriched in 291 KEEG pathways, with most of them belonging to immune and material metabolic pathways. The large number of transcriptome data and pathways determined in this study provide a database foundation for the toxicity analysis of ENR in loach cells, which must be thoroughly examined to further investigate the cytotoxic mechanism of antibiotics in fish cells.


Assuntos
Antibacterianos , Cipriniformes , Adenosina Trifosfatases , Animais , Antibacterianos/toxicidade , Apoptose , Enrofloxacina
17.
Appl Opt ; 61(8): 1994-2006, 2022 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-35297892

RESUMO

In this paper, the problems of decreasing coupling efficiency and energy distribution divergence of water beam fiber caused by static alignment deviation are studied. Based on the basic conditions of coupling between laser and water beam fiber, the mathematical model of coupling efficiency of water beam fiber is established, and the calculation equation of coupling efficiency is modified. The variation of coupling efficiency and energy distribution of water beam fiber under the influence of static alignment deviation is analyzed by numerical simulation, and the correctness of theoretical derivation and simulation model is verified by experiments. The results show that the lateral deviation changes the transmission path of laser in the water beam fiber to a large extent, and its influence on the energy distribution in the water beam fiber is greater than that of longitudinal deviation and angular deviation.

18.
Acta Pharmacol Sin ; 42(3): 347-360, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33462377

RESUMO

DL-3-n-Butylphthalide (DL-NBP), a small molecular compound extracted from the seeds of Apium graveolens Linn (Chinese celery), has been shown to exert neuroprotective effects due to its anti-inflammatory, anti-oxidative and anti-apoptotic activities. DL-NBP not only protects against ischemic cerebral injury, but also ameliorates vascular cognitive impairment in dementia patients including AD and PD. In the current study, we investigated whether and how DL-NBP exerted a neuroprotective effect against diabetes-associated cognitive decline (DACD) in db/db mice, a model of type-2 diabetes. db/db mice were orally administered DL-NBP (20, 60, 120 mg· kg-1· d-1) for 8 weeks. Then the mice were subjected to behavioral test, their brain tissue was collected for morphological and biochemical analyses. We showed that oral administration of DL-NBP significantly ameliorated the cognitive decline with improved learning and memory function in Morris water maze testing. Furthermore, DL-NBP administration attenuated diabetes-induced morphological alterations and increased neuronal survival and restored the levels of synaptic protein PSD95, synaptophysin and synapsin-1 as well as dendritic density in the hippocampus, especially at a dose of 60 mg/kg. Moreover, we revealed that DL-NBP administration suppressed oxidative stress by upregulating Nrf2/HO-1 signaling, and increased brain-derived neurotrophic factor (BDNF) expression by activating PI3K/Akt/CREB signaling in the hippocampus. These beneficial effects of DL-NBP were observed in high glucose-treated PC12 cells. Our results suggest that DL-NBP may be a potential pharmacologic agent for the treatment of DACD.


Assuntos
Benzofuranos/uso terapêutico , Disfunção Cognitiva/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Disfunção Cognitiva/etiologia , Dendritos/efeitos dos fármacos , Diabetes Mellitus Tipo 2/complicações , Hipocampo/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Teste do Labirinto Aquático de Morris/efeitos dos fármacos , Células PC12 , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Sinapses/efeitos dos fármacos
19.
Neural Regen Res ; 16(4): 765-771, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33063740

RESUMO

The blood-spinal cord barrier plays a vital role in recovery after spinal cord injury. The neurovascular unit concept emphasizes the relationship between nerves and vessels in the brain, while the effect of the blood-spinal cord barrier on the neurovascular unit is rarely reported in spinal cord injury studies. Mouse models of spinal cord injury were established by heavy object impact and then immediately injected with platelet-derived growth factor (80 µg/kg) at the injury site. Our results showed that after platelet-derived growth factor administration, spinal cord injury, neuronal apoptosis, and blood-spinal cord barrier permeability were reduced, excessive astrocyte proliferation and the autophagy-related apoptosis signaling pathway were inhibited, collagen synthesis was increased, and mouse locomotor function was improved. In vitro, human umbilical vein endothelial cells were established by exposure to 200 µM H2O2. At 2 hours prior to injury, in vitro cell models were treated with 5 ng/mL platelet-derived growth factor. Our results showed that expression of blood-spinal cord barrier-related proteins, including Occludin, Claudin 5, and ß-catenin, was significantly decreased and autophagy was significantly reduced. Additionally, the protective effects of platelet-derived growth factor could be reversed by intraperitoneal injection of 80 mg/kg chloroquine, an autophagy inhibitor, for 3 successive days prior to spinal cord injury. Our findings suggest that platelet-derived growth factor can promote endothelial cell repair by regulating autophagy, improve the function of the blood-spinal cord barrier, and promote the recovery of locomotor function post-spinal cord injury. Approval for animal experiments was obtained from the Animal Ethics Committee, Wenzhou Medical University, China (approval No. wydw2018-0043) in July 2018.

20.
Theranostics ; 10(20): 9280-9302, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32802192

RESUMO

Background and Aim: Increasing evidence suggests that spinal cord injury (SCI)-induced defects in autophagic flux may contribute to an impaired ability for neurological repair following injury. Transcription factor E3 (TFE3) plays a crucial role in oxidative metabolism, lysosomal homeostasis, and autophagy induction. Here, we investigated the role of TFE3 in modulating autophagy following SCI and explored its impact on neurological recovery. Methods: Histological analysis via HE, Nissl and Mason staining, survival rate analysis, and behavioral testing via BMS and footprint analysis were used to determine functional recovery after SCI. Quantitative real-time polymerase chain reaction, Western blotting, immunofluorescence, TUNEL staining, enzyme-linked immunosorbent assays, and immunoprecipitation were applied to examine levels of autophagy flux, ER-stress-induced apoptosis, oxidative stress, and AMPK related signaling pathways. In vitro studies using PC12 cells were performed to discern the relationship between ROS accumulation and autophagy flux blockade. Results: Our results showed that in SCI, defects in autophagy flux contributes to ER stress, leading to neuronal death. Furthermore, SCI enhances the production of reactive oxygen species (ROS) that induce lysosomal dysfunction to impair autophagy flux. We also showed that TFE3 levels are inversely correlated with ROS levels, and increased TFE3 levels can lead to improved outcomes. Finally, we showed that activation of TFE3 after SCI is partly regulated by AMPK-mTOR and AMPK-SKP2-CARM1 signaling pathways. Conclusions: TFE3 is an important regulator in ROS-mediated autophagy dysfunction following SCI, and TFE3 may serve as a promising target for developing treatments for SCI.


Assuntos
Autofagia/fisiologia , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Estresse do Retículo Endoplasmático/fisiologia , Traumatismos da Medula Espinal/metabolismo , Animais , Apoptose/fisiologia , Morte Celular/fisiologia , Linhagem Celular Tumoral , Feminino , Lisossomos/metabolismo , Lisossomos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/metabolismo , Neurônios/patologia , Células PC12 , Ratos , Espécies Reativas de Oxigênio/metabolismo , Recuperação de Função Fisiológica/fisiologia , Transdução de Sinais/fisiologia , Traumatismos da Medula Espinal/patologia , Serina-Treonina Quinases TOR/metabolismo , Fatores de Transcrição/metabolismo
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