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1.
Sensors (Basel) ; 24(9)2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38732913

RESUMO

The Controller Area Network (CAN), widely used for vehicular communication, is vulnerable to multiple types of cyber-threats. Attackers can inject malicious messages into the CAN bus through various channels, including wireless methods, entertainment systems, and on-board diagnostic ports. Therefore, it is crucial to develop a reliable intrusion detection system (IDS) capable of effectively distinguishing between legitimate and malicious CAN messages. In this paper, we propose a novel IDS architecture aimed at enhancing the cybersecurity of CAN bus systems in vehicles. Various machine learning (ML) models have been widely used to address similar problems; however, although existing ML-based IDS are computationally efficient, they suffer from suboptimal detection performance. To mitigate this shortcoming, our architecture incorporates specially designed rule-based filters that cross-check outputs from the traditional ML-based IDS. These filters scrutinize message ID and payload data to precisely capture the unique characteristics of three distinct types of cyberattacks: DoS attacks, spoofing attacks, and fuzzy attacks. Experimental evidence demonstrates that the proposed architecture leads to a significant improvement in detection performance across all utilized ML models. Specifically, all ML-based IDS achieved an accuracy exceeding 99% for every type of attack. This achievement highlights the robustness and effectiveness of our proposed solution in detecting potential threats.

2.
Sensors (Basel) ; 24(11)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38894398

RESUMO

Image denoising is regarded as an ill-posed problem in computer vision tasks that removes additive noise from imaging sensors. Recently, several convolution neural network-based image-denoising methods have achieved remarkable advances. However, it is difficult for a simple denoising network to recover aesthetically pleasing images owing to the complexity of image content. Therefore, this study proposes a multi-branch network to improve the performance of the denoising method. First, the proposed network is designed based on a conventional autoencoder to learn multi-level contextual features from input images. Subsequently, we integrate two modules into the network, including the Pyramid Context Module (PCM) and the Residual Bottleneck Attention Module (RBAM), to extract salient information for the training process. More specifically, PCM is applied at the beginning of the network to enlarge the receptive field and successfully address the loss of global information using dilated convolution. Meanwhile, RBAM is inserted into the middle of the encoder and decoder to eliminate degraded features and reduce undesired artifacts. Finally, extensive experimental results prove the superiority of the proposed method over state-of-the-art deep-learning methods in terms of objective and subjective performances.

3.
Sensors (Basel) ; 23(24)2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-38139503

RESUMO

Facial expression recognition is crucial for understanding human emotions and nonverbal communication. With the growing prevalence of facial recognition technology and its various applications, accurate and efficient facial expression recognition has become a significant research area. However, most previous methods have focused on designing unique deep-learning architectures while overlooking the loss function. This study presents a new loss function that allows simultaneous consideration of inter- and intra-class variations to be applied to CNN architecture for facial expression recognition. More concretely, this loss function reduces the intra-class variations by minimizing the distances between the deep features and their corresponding class centers. It also increases the inter-class variations by maximizing the distances between deep features and their non-corresponding class centers, and the distances between different class centers. Numerical results from several benchmark facial expression databases, such as Cohn-Kanade Plus, Oulu-Casia, MMI, and FER2013, are provided to prove the capability of the proposed loss function compared with existing ones.


Assuntos
Reconhecimento Facial , Redes Neurais de Computação , Humanos , Algoritmos , Expressão Facial , Emoções
4.
Pharmacol Res ; 184: 106423, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36064078

RESUMO

BMP2 is clinically used as an ectopic bone inducer and plays a significant role in bone development, formation, and diseases. Chitinase 3-like 1 protein (Chi3L1) is found in the skeletal system. However, Chi3L1-mediated bone metabolism and aging-related bone erosion via BMP2 signaling have not yet been demonstrated. Herein, Chi3L1 increased BMP2-induced osteoblast differentiation in mesenchymal precursor cells and human primary osteoblasts. Chi3L1KO(-/-) showed abnormal bone development, and primary osteoblasts isolated from Chi3L1KO(-/-) exhibited impaired osteoblast differentiation and maturation. Chi3L1 also potentiated BMP2 signaling and RUNX2 expression in primary osteoblasts. Chi3L1 interacted with BMPRIa, which increased the surface expression of BMPRIa and promoted BMP2 signaling to induce osteoblast differentiation. Chi3L1KO(-/-) mice showed bone formation reduced with a decrease in RUNX2 expression in calvarial defects. Chi3L1KO(-/-) mice exhibited aging-related osteoporotic bone loss with decreases in the levels of RUNX2 and OPG, while serum PYD level and osteoclast number increased. Chi3L1 increased OPG via non-canonical BMP2 signaling in osteoblasts, which suppressed osteoclastogenesis in BMMs. Furthermore, ROC analysis showed that serum Chi3L1 level clinically decreased in osteoporosis patients. Our findings demonstrate that Chi3L1 promotes bone formation, suppresses osteoclastogenesis, and prevents aging-related osteoporosis.


Assuntos
Quitinases , Osteoporose , Animais , Biomarcadores/metabolismo , Diferenciação Celular , Proteína 1 Semelhante à Quitinase-3/genética , Proteína 1 Semelhante à Quitinase-3/metabolismo , Quitinases/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Humanos , Camundongos , Osteoblastos/metabolismo , Osteogênese , Osteoporose/tratamento farmacológico , Osteoporose/metabolismo
5.
Org Biomol Chem ; 19(29): 6546-6557, 2021 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-34259297

RESUMO

Multitarget engagement is considered an effective strategy to overcome the threat of bacterial infection, and antimicrobials with multiple mechanisms of action have been successful as natural chemical weaponry. Here, we synthesized a library of photosensitizer-peptoid conjugates (PsPCs) as novel antimicrobial photodynamic therapy (aPDT) agents. The peptoids, linkers, and photosensitizers were varied, and their structure-antimicrobial activity relationships against Escherichia coli were evaluated; PsPC 9 was indicated to be the most promising photoresponsive antimicrobial agent among the synthesized PsPCs. Spectroscopic analyses indicated that 9 generated singlet oxygen upon absorption of visible light (420 nm) while maintaining the weakly helical conformation of the peptoid. Mechanistic studies suggested that damage to the bacterial membrane and cleavage of DNA upon light irradiation were the main causes of bactericidal activity, which was supported by flow cytometry and DNA gel electrophoresis experiments. We demonstrated that the optimal combination of membrane-active peptoids and photosensitizers can generate an efficient aPDT agent that targets multiple sites of bacterial components and kills bacteria by membrane disruption and reactive oxygen species generation.


Assuntos
Fármacos Fotossensibilizantes
6.
Proc Natl Acad Sci U S A ; 115(38): E8844-E8853, 2018 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-30185553

RESUMO

Calcium (Ca2+) homeostasis is essential for neuronal function and survival. Altered Ca2+ homeostasis has been consistently observed in neurological diseases. How Ca2+ homeostasis is achieved in various cellular compartments of disease-relevant cell types is not well understood. Here we show in Drosophila Parkinson's disease (PD) models that Ca2+ transport from the endoplasmic reticulum (ER) to mitochondria through the ER-mitochondria contact site (ERMCS) critically regulates mitochondrial Ca2+ (mito-Ca2+) homeostasis in dopaminergic (DA) neurons, and that the PD-associated PINK1 protein modulates this process. In PINK1 mutant DA neurons, the ERMCS is strengthened and mito-Ca2+ level is elevated, resulting in mitochondrial enlargement and neuronal death. Miro, a well-characterized component of the mitochondrial trafficking machinery, mediates the effects of PINK1 on mito-Ca2+ and mitochondrial morphology, apparently in a transport-independent manner. Miro overexpression mimics PINK1 loss-of-function effect, whereas inhibition of Miro or components of the ERMCS, or pharmacological modulation of ERMCS function, rescued PINK1 mutant phenotypes. Mito-Ca2+ homeostasis is also altered in the LRRK2-G2019S model of PD and the PAR-1/MARK model of neurodegeneration, and genetic or pharmacological restoration of mito-Ca2+ level is beneficial in these models. Our results highlight the importance of mito-Ca2+ homeostasis maintained by Miro and the ERMCS to mitochondrial physiology and neuronal integrity. Targeting this mito-Ca2+ homeostasis pathway holds promise for a therapeutic strategy for neurodegenerative diseases.


Assuntos
Cálcio/metabolismo , Drosophila melanogaster/metabolismo , Retículo Endoplasmático/metabolismo , Mitocôndrias/metabolismo , Doença de Parkinson/patologia , Animais , Animais Geneticamente Modificados , Quelantes/farmacologia , Modelos Animais de Doenças , Neurônios Dopaminérgicos/citologia , Neurônios Dopaminérgicos/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Retículo Endoplasmático/efeitos dos fármacos , Quinase 3 da Glicogênio Sintase/metabolismo , Humanos , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/metabolismo , Mutação com Perda de Função , Mitocôndrias/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo
7.
Int J Neurosci ; 131(1): 7-14, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32075484

RESUMO

Aim: Glioma stem cells (GSCs) have been shown to contribute to tumor development and recurrence, therapeutic resistance, and cellular heterogeneity of glioblastoma multiforme (GBM). Recently, it has been reported that GSCs lose their self-renewal ability and tumorigenic potential upon differentiation. In this study, we identified Regulatory Factor X4 (RFX4) gene to regulate GSCs' survival and self-renewal activity in the GBM patients samples.Materials and methods: We utilized public datasets from the Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), Ivy Glioblastoma Atlas Project, and The Human Protein Atlas to screen candidate genes which are associated with the development of GBM and poor patients survival. Small hairpin RNA (shRNA) lentivirus was applied to knockdown RFX4 gene in GSCs.Results: We found that RFX4 mRNA expression among the RFX family was particularly reduced during GSC differentiation. RT-qPCR analysis revealed significant downregulation of RFX4 and stem cell markers (CD15 and CD133) mRNA expressions in primary human GBM-derived GSCs cultured under serum condition. Consistently, GSCs showed significantly elevated RFX4 mRNA expression levels compared to normal astrocytes, NHA, whereas glioma cells did not. Furthermore, analysis of the TCGA data set revealed that RFX4 is highly expressed in GBM, and contributes to the lowering of patient survival. Depletion of RFX4 using shRNA lentivirus in patient GBM-derived GSCs decreased neurosphere formation and cell viability.Conclusion: These results suggest that RFX4 is a potential risk factor for maintaining the stemness of GSCs and making glioma more malignant, and thus, could be a promising target of GBM treatment.


Assuntos
Biomarcadores Tumorais/biossíntese , Neoplasias Encefálicas/metabolismo , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Glioblastoma/metabolismo , Fatores de Transcrição de Fator Regulador X/biossíntese , Biomarcadores Tumorais/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/fisiologia , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Prognóstico , Fatores de Transcrição de Fator Regulador X/genética
8.
Nano Lett ; 20(10): 7168-7176, 2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-32876460

RESUMO

Polystyrene nanoparticles (PS-NPs) derived from both environmental and occupational sources are an important class of ultrafine particles associated with human pulmonary disorders. The effects of surface charges of particle internalization and toxicity to alveolar cells, especially under conditions comparable to those found during breathing, have not been examined. Here, we applied cyclic stretches (CS) to human alveolar cells during nanoparticle exposure and show an enhanced accumulation of positively charged polystyrene nanoparticles as compared to similar negatively charged particles. The cellular uptake of the positive particles into live cells was visualized with three-dimensional optical diffraction tomography (3-D ODT). The simultaneous application of both periodic stretching as well as positively charged nanoparticles led to blebbing morphology and activation of apoptotic signaling compared to control cells. Our findings provide a better understanding of how surface charge mediates the uptake and toxicity of nanoplastics under the dynamical mechanical conditions relevant for breathing exposures.


Assuntos
Microplásticos , Nanopartículas , Células Epiteliais Alveolares , Humanos , Nanopartículas/toxicidade , Tamanho da Partícula , Poliestirenos
9.
Medicina (Kaunas) ; 57(10)2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34684161

RESUMO

Background and Objectives: Appropriate catheter selection when conducting transradial coronary angiography (CAG) helps shorten examination time, preventing vascular complications and lowering medical expense. However, catheter selection is made based on the practitioner's experience in almost all cases. Therefore, we undertook this study to define radiologic and echocardiographic indices that would enable physicians to anticipate appropriate catheter selection. Materials and Methods: This is a retrospective study of 244 undergoing transradial diagnostic CAG at an established center from February 2006 to April 2014. Patients who successfully underwent angiography with a JL3.5 catheter were defined as the control group, and patients who successfully underwent angiography after the catheter was replaced with a JL4.0 or higher were defined as the switched group. To identify predictors for appropriate catheter selection, radiologic and echocardiographic indices were analyzed. Results: A total of 122 patients in the switched group and 122 patients in the control group were analyzed in this study. Average age was 64.65 ± 8.6 years. In the radiographic index, the switched group exhibited a significantly higher mediastinal-thoracic ratio (0.27 ± 0.05 vs. 0.23 ± 0.03, p < 0.001. Additionally, the mediastinal-cardiac ratio was significantly greater in the switched group (0.50 ± 0.08 vs. 0.45 ± 0.05, p < 0.001). Aortic root diameter, which is used here as the echocardiographic index, was significantly larger in the switched group compared to the control group (34.94 ± 4.18 mm vs. 32.66 ± 3.99 mm, p < 0.001). In the multivariable logistic regression model, mediastinal-cardiac ratio (OR 5.197, 95% CI 2.608-10.355, p < 0.001) and increased aortic root (OR 2.115, 95% CI 1.144-3.912, p = 0.017) were significantly associated with catheter change. Conclusions: Mediastinal-cardiac ratio and aortic root diameter provide helpful and effective indices for appropriate catheter selection during transradial coronary angiography.


Assuntos
Cateteres Cardíacos , Artéria Radial , Idoso , Catéteres , Angiografia Coronária , Ecocardiografia , Humanos , Pessoa de Meia-Idade , Artéria Radial/diagnóstico por imagem , Estudos Retrospectivos
10.
J Neuroinflammation ; 17(1): 299, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-33054766

RESUMO

BACKGROUND: Cytoplasmic inclusions of transactive response DNA binding protein of 43 kDa (TDP-43) in neurons and astrocytes are a feature of some neurodegenerative diseases, such as frontotemporal lobar degeneration with TDP-43 (FTLD-TDP) and amyotrophic lateral sclerosis (ALS). However, the role of TDP-43 in astrocyte pathology remains largely unknown. METHODS: To investigate whether TDP-43 overexpression in primary astrocytes could induce inflammation, we transfected primary astrocytes with plasmids encoding Gfp or TDP-43-Gfp. The inflammatory response and upregulation of PTP1B in transfected cells were examined using quantitative RT-PCR and immunoblot analysis. Neurotoxicity was analysed in a transwell coculture system of primary cortical neurons with astrocytes and cultured neurons treated with astrocyte-conditioned medium (ACM). We also examined the lifespan, performed climbing assays and analysed immunohistochemical data in pan-glial TDP-43-expressing flies in the presence or absence of a Ptp61f RNAi transgene. RESULTS: PTP1B inhibition suppressed TDP-43-induced secretion of inflammatory cytokines (interleukin 1 beta (IL-1ß), interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α)) in primary astrocytes. Using a neuron-astrocyte coculture system and astrocyte-conditioned media treatment, we demonstrated that PTP1B inhibition attenuated neuronal death and mitochondrial dysfunction caused by overexpression of TDP-43 in astrocytes. In addition, neuromuscular junction (NMJ) defects, a shortened lifespan, inflammation and climbing defects caused by pan-glial overexpression of TDP-43 were significantly rescued by downregulation of ptp61f (the Drosophila homologue of PTP1B) in flies. CONCLUSIONS: These results indicate that PTP1B inhibition mitigates the neuronal toxicity caused by TDP-43-induced inflammation in mammalian astrocytes and Drosophila glial cells.


Assuntos
Astrócitos/metabolismo , Proteínas de Ligação a DNA/biossíntese , Mediadores da Inflamação/metabolismo , Degeneração Neural/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Proteína Tirosina Fosfatase não Receptora Tipo 1/biossíntese , Animais , Animais Geneticamente Modificados , Astrócitos/patologia , Células Cultivadas , Proteínas de Ligação a DNA/genética , Drosophila , Expressão Gênica , Mediadores da Inflamação/antagonistas & inibidores , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Degeneração Neural/genética , Degeneração Neural/patologia , Proteína Tirosina Fosfatase não Receptora Tipo 1/genética
11.
Molecules ; 25(16)2020 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-32781622

RESUMO

Cyclodextrins (CDs) are used as drug delivery agents. In this study, we examined whether CDs have an inflammatory effect on endothelial cells. First, we found that ß-CD promoted cell proliferation in bovine aortic endothelial cells and elevated nitric oxide (NO) production through dephosphorylation of threonine-495 (T-495) in endothelial nitric oxide synthetase (eNOS). Dephosphorylation of T-495 is known to activate eNOS. Phosphorylation of T-495 was found to be catalyzed by protein kinase Cε (PKCε). We then found that ß-CD inhibits binding of PKCε to diacylglycerol (DAG) via formation of a ß-CD-DAG complex, indicating that ß-CD inactivates PKCε. Furthermore, ß-CD controls activation of PKCε by reducing the recruitment of PKCε into the plasma membrane. Finally, ß-CD inhibits expression of intercellular and vascular cell adhesion molecule-1 by increasing NO via control of PKCε/eNOS and suppression of THP-1 cell adhesion to endothelial cells. These findings imply that ß-CD plays an important role in anti-inflammatory processes.


Assuntos
Moléculas de Adesão Celular/metabolismo , Adesão Celular/efeitos dos fármacos , Células Endoteliais/citologia , Monócitos/citologia , Monócitos/efeitos dos fármacos , beta-Ciclodextrinas/farmacologia , Animais , Bovinos , Monócitos/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Proteína Quinase C-épsilon/metabolismo
12.
Biochem Biophys Res Commun ; 513(4): 925-932, 2019 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-31005259

RESUMO

The most prominent hallmarks of many neurodegenerative diseases are the accumulation of misfolded protein aggregates and the death of certain neuronal populations. Autophagy is the major intracellular mechanism that degrades protein aggregates and damaged cellular components. Many studies have reported that the dysfunction of autophagy is associated with several neurodegenerative diseases, such as Alzheimer's disease, amyotrophic lateral sclerosis (ALS), and Parkinson's disease. Here, we identified a novel mechanism of autophagy regulation. Inhibition of MEK5 reduced the level of p62 and increased the ratio of LC3-II to LC3-I, which is a marker for the activation of the autophagy-lysosome pathway (ALP). One of the most well-known regulators of the ALP is mTOR, and previous studies have reported that the major substrate of MEK5 is ERK5. However, we found that MEK5 modulates the autophagy-lysosome pathway in an mTOR- and ERK5-independent manner. Moreover, MEK5 inhibition alleviated the mislocalization of TDP-43 (an ALS-associated protein) and cell death in TDP-43-GFP-expressing neuronal cells. Taken together, these findings suggest that MEK5 is a novel autophagy modulator and that this kinase could be a therapeutic target for neurodegenerative diseases such as amyotrophic lateral sclerosis.


Assuntos
Autofagia , Proteínas de Ligação a DNA/toxicidade , Lisossomos/metabolismo , MAP Quinase Quinase 5/antagonistas & inibidores , Redes e Vias Metabólicas/fisiologia , Neurônios/citologia , Animais , Humanos , Proteínas Associadas aos Microtúbulos/metabolismo , Neurônios/metabolismo , Proteínas de Ligação a RNA/metabolismo , Serina-Treonina Quinases TOR/fisiologia
13.
Small ; 15(44): e1903705, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31523914

RESUMO

Hexagonal boron nitride (hBN) has great potential as a promising gas barrier layer in proton exchange membrane fuel cells (PEMFCs) as it shows high proton conductivity as well as excellent gas-blocking capability. However, structural defects and mechanical damage during the transfer of the hBN layer and membrane swelling have limited the application of hBN sheets to PEMFCs. Here, an ultrathin gas barrier layer is successfully fabricated on a proton exchange membrane via reconstruction of mechanically exfoliated hBN nanoflakes using a direct spin-coating process. The hBN-coated layer effectively suppresses the gas crossover and inhibits the formation of reactive oxygen radicals in the electrodes without reducing the proton conductivity of the membrane. It is also demonstrated that the structural advantages of hBN-coated gas barrier layers promise high performance of a unit cell even after a open-circuit voltage (OCV) hold test for 100 h. Furthermore, through in-depth postmortem analyses, a time-dependent degradation mechanism of membrane electrode assembly under the OCV condition is rationally proposed.

14.
Int J Mol Sci ; 21(1)2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31861806

RESUMO

Developmentally regulated GTP-binding protein 2 (DRG2) was first identified in the central nervous system of mice. However, the physiological function of DRG2 in the brain remains largely unknown. Here, we demonstrated that knocking out DRG2 impairs the function of dopamine neurons in mice. DRG2 was strongly expressed in the neurons of the dopaminergic system such as those in the striatum (Str), ventral tegmental area (VTA), and substantia nigra (SN), and on neuronal cell bodies in high-density regions such as the hippocampus (HIP), cerebellum, and cerebral cortex in the mouse brain. DRG2 knockout (KO) mice displayed defects in motor function in motor coordination and rotarod tests and increased anxiety. However, unexpectedly, DRG2 depletion did not affect the dopamine (DA) neuron population in the SN, Str, or VTA region or dopamine synthesis in the Str region. We further demonstrated that dopamine release was significantly diminished in the Str region of DRG2 KO mice and that treatment of DRG2 KO mice with l-3,4-dihydroxyphenylalanine (L-DOPA), a dopamine precursor, rescued the behavioral motor deficiency in DRG2 KO mice as observed with the rotarod test. This is the first report to identify DRG2 as a key regulator of dopamine release from dopamine neurons in the mouse brain.


Assuntos
Corpo Estriado/metabolismo , Dopamina/metabolismo , Proteínas de Ligação ao GTP/genética , Transtornos Motores/genética , Animais , Ansiedade/genética , Ansiedade/metabolismo , Corpo Estriado/citologia , Neurônios Dopaminérgicos/citologia , Neurônios Dopaminérgicos/metabolismo , Proteínas de Ligação ao GTP/análise , Proteínas de Ligação ao GTP/metabolismo , Deleção de Genes , Camundongos , Camundongos Knockout , Transtornos Motores/metabolismo
15.
Biochem Biophys Res Commun ; 481(3-4): 259-264, 2016 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-27810362

RESUMO

Amyotrophic lateral sclerosis (ALS) is the most common neurodegenerative disease, characterized by progressive and selective loss of motor neurons in the brain and spinal cord. DNA/RNA-binding proteins such as TDP-43, FUS, and TAF15 have been linked with the sporadic and familial forms of ALS. However, the exact pathogenic mechanism of ALS is still unknown. Recently, we found that ALS-causing genes such as TDP-43, FUS, and TAF15 genetically interact with mitochondrial dynamics regulatory genes. In this study, we show that mitochondrial fission was highly enhanced in muscles and motor neurons of TDP-43, FUS, and TAF15-induced fly models of ALS. Furthermore, the mitochondrial fission defects were rescued by co-expression of mitochondrial dynamics regulatory genes such as Marf, Opa1, and the dominant negative mutant form of Drp1. Moreover, we found that the expression level of Marf was decreased in ALS-induced flies. These results indicate that the imbalance of mitochondrial dynamics caused by instability of Marf is linked to the pathogenesis of TDP-43, FUS, and TAF15-associated ALS.


Assuntos
Esclerose Lateral Amiotrófica/metabolismo , Drosophila melanogaster/metabolismo , Dinâmica Mitocondrial , Esclerose Lateral Amiotrófica/genética , Animais , Modelos Animais de Doenças , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Regulação da Expressão Gênica , Cabeça , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Dinâmica Mitocondrial/genética , Modelos Biológicos , Estabilidade Proteica , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
16.
PLoS Genet ; 8(3): e1002537, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22396657

RESUMO

Mutations in Pten-induced kinase 1 (PINK1) are linked to early-onset familial Parkinson's disease (FPD). PINK1 has previously been implicated in mitochondrial fission/fusion dynamics, quality control, and electron transport chain function. However, it is not clear how these processes are interconnected and whether they are sufficient to explain all aspects of PINK1 pathogenesis. Here we show that PINK1 also controls mitochondrial motility. In Drosophila, downregulation of dMiro or other components of the mitochondrial transport machinery rescued dPINK1 mutant phenotypes in the muscle and dopaminergic (DA) neurons, whereas dMiro overexpression alone caused DA neuron loss. dMiro protein level was increased in dPINK1 mutant but decreased in dPINK1 or dParkin overexpression conditions. In Drosophila larval motor neurons, overexpression of dPINK1 inhibited axonal mitochondria transport in both anterograde and retrograde directions, whereas dPINK1 knockdown promoted anterograde transport. In HeLa cells, overexpressed hPINK1 worked together with hParkin, another FPD gene, to regulate the ubiquitination and degradation of hMiro1 and hMiro2, apparently in a Ser-156 phosphorylation-independent manner. Also in HeLa cells, loss of hMiro promoted the perinuclear clustering of mitochondria and facilitated autophagy of damaged mitochondria, effects previously associated with activation of the PINK1/Parkin pathway. These newly identified functions of PINK1/Parkin and Miro in mitochondrial transport and mitophagy contribute to our understanding of the complex interplays in mitochondrial quality control that are critically involved in PD pathogenesis, and they may explain the peripheral neuropathy symptoms seen in some PD patients carrying particular PINK1 or Parkin mutations. Moreover, the different effects of loss of PINK1 function on Miro protein level in Drosophila and mouse cells may offer one explanation of the distinct phenotypic manifestations of PINK1 mutants in these two species.


Assuntos
Transporte Axonal , Proteínas de Drosophila/genética , Drosophila , Doença de Parkinson/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas rho de Ligação ao GTP/genética , Animais , Autofagia/genética , Transporte Axonal/genética , Carbonil Cianeto m-Clorofenil Hidrazona/farmacologia , Modelos Animais de Doenças , Neurônios Dopaminérgicos/metabolismo , Drosophila/genética , Proteínas de Drosophila/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Células HeLa , Humanos , Camundongos , Camundongos Knockout , Mitocôndrias/genética , Mitocôndrias/metabolismo , Neurônios Motores/metabolismo , Proteínas Mutantes/metabolismo , Doença de Parkinson/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Ionóforos de Próton/farmacologia , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo
17.
Angew Chem Int Ed Engl ; 54(39): 11472-6, 2015 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-26178411

RESUMO

The abnormal assembly of ß-amyloid (Aß) peptides into neurotoxic, ß-sheet-rich amyloid aggregates is a major pathological hallmark of Alzheimer's disease (AD). Light-induced photosensitizing molecules can regulate Aß amyloidogenesis. Multiple photochemical analyses using circular dichroism, atomic force microscopy, dot blot, and native gel electrophoresis verified that photoactivated meso-tetra(4-sulfonatophenyl)porphyrin (TPPS with M = 2H(+), Zn(2+), Cu(2+), Mn(2+)) successfully inhibits Aß aggregation in vitro. Furthermore, Aß toxicity was relieved in the photoexcited-TPPS-treated Drosophila AD model. TPPS suppresses neural cell death, synaptic toxicity, and behavioral defects in the Drosophila AD model under blue light illumination. Behavioral phenotypes, including larval locomotion defect and short lifespan caused by Aß overexpression, were also rescued by blue light-excited TPPS.


Assuntos
Peptídeos beta-Amiloides/química , Porfirinas/química , Sinapses/efeitos dos fármacos , Peptídeos beta-Amiloides/toxicidade , Animais , Drosophila , Processos Fotoquímicos
18.
Curr Opin Cell Biol ; 87: 102342, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38428224

RESUMO

Lipid droplets (LDs), once considered mere storage depots for lipids, have gained recognition for their intricate roles in cellular processes, including metabolism, membrane trafficking, and disease states like obesity and cancer. This review explores label-free imaging techniques' applications in LD research. We discuss holotomography and vibrational spectroscopic microscopy, emphasizing their potential for studying LDs without molecular labels, and we highlight the growing integration of artificial intelligence. Clinical applications in disease diagnosis and therapy are also considered.


Assuntos
Inteligência Artificial , Gotículas Lipídicas , Gotículas Lipídicas/metabolismo , Microscopia , Metabolismo dos Lipídeos
19.
J Microbiol Biotechnol ; 34(1): 123-131, 2024 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-37830224

RESUMO

Lactic acid bacteria (LAB) isolated from kimchi have various functions, including antioxidant, anti-inflammation, and anti-obesity activities, and are therefore widely used in the food, pharmaceutical, and medical fields. To date, the health functionalities of LAB have been widely reported; however, those of kimchi fermented with LAB as a starter have rarely been reported. Therefore, research on the selection of LAB with anti-obesity activity and the health functionality of kimchi fermented with LAB is needed. In the present study, LAB with anti-obesity activity were initially selected by measuring the Oil-Red O intensity. Among the four LAB strains, anti-obesity activity was confirmed by measuring cell viability, lipid levels, and lipid accumulation. Then, starter kimchi (SK) was prepared by inoculating selected LABs, and its pH, total acidity, and salinity were compared with those of naturally fermented kimchi (NK). Lastly, anti-obesity activity was also investigated in 3T3-L1 cells. Selected LAB showed no cytotoxicity up to 107 CFU/ml, with Lactobacillus brevis JC7 and Leuconostoc mesenteroides KCKM0828 having higher inhibitory effects on TG, TC content and lipid accumulation. Most SKs showed fermentation properties similar to those of the NK. SKs showed no cytotoxicity at concentrations of up to 1,000 µg/ml. SKs showed strong inhibitory effects on TG content, lipid accumulation, and obesity-related gene and protein expressions. Taken together, the utilization of LAB as a starter could improve the health benefits of kimchi.


Assuntos
Alimentos Fermentados , Hipercolesterolemia , Lactobacillales , Camundongos , Animais , Células 3T3-L1 , Obesidade/tratamento farmacológico , Fermentação , Lipídeos , Alimentos Fermentados/microbiologia , Microbiologia de Alimentos
20.
Anim Cells Syst (Seoul) ; 28(1): 93-109, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38487309

RESUMO

Myeloid ecotropic virus insertion site 1 (MEIS1) is a HOX co-factor necessary for organ development and normal hematopoiesis. Recently, MEIS1 has been linked to the development and progression of various cancers. However, its role in gliomagenesis particularly on glioma stem cells (GSCs) remains unclear. Here, we demonstrate that MEIS1 is highly upregulated in GSCs compared to normal, and glioma cells and to its differentiated counterparts. Inhibition of MEIS1 expression by shRNA significantly reduced GSC growth in both in vitro and in vivo experiments. On the other hand, integrated transcriptomics analyses of glioma datasets revealed that MEIS1 expression is correlated to cell cycle-related genes. Clinical data analysis revealed that MEIS1 expression is elevated in high-grade gliomas, and patients with high MEIS1 levels have poorer overall survival outcomes. The findings suggest that MEIS1 is a prognostic biomarker for glioma patients and a possible target for developing novel therapeutic strategies against GBM.

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