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1.
Brain ; 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38976650

RESUMO

Mutations in the GBA1 gene are common genetic risk factors for Parkinson's disease (PD), disrupting enzymatic activity and causing lysosomal dysfunction, leading to elevated α-synuclein (α-syn) levels. While GBA1's role in synucleinopathy is well-established, recent research underscores neuroinflammation as a significant pathogenic mechanism in GBA1 deficiency. This study investigates neuroinflammation in Gba1 E326K knock-in mice, a model associated with increased PD and dementia risk. At 9 and 24 months, we assessed GBA1 protein and activity, α-synuclein pathology, neurodegeneration, motor deficits, and gliosis in the ventral midbrain and hippocampus using immunohistochemistry (IHC), Western blot (WB), and GCase assays. Additionally, primary microglia from WT and GBA1E326K/E326K mice were treated with α-syn preformed fibrils (PFF) to study microglia activation, pro-inflammatory cytokines, reactive astrocyte formation, and neuronal death through qPCR, WB, and immunocytochemistry analyses. We also evaluated the effects of gut inoculation of α-syn PFF in Gba1 E326K mice at 7 months and striatal inoculation at 10 months, assessing motor/non-motor symptoms, α-syn pathology, neuroinflammation, gliosis, and neurodegeneration via behavioural tests, IHC, and WB assays. At 24 months, Gba1 E326K knock-in mice showed reduced GCase enzymatic activity and glucosylceramide build-up in the ventral midbrain and hippocampus. Increased pro-inflammatory cytokines and reactive astrocytes were observed in microglia and astrocytes from Gba1 E326K mice treated with pathologic α-syn PFF. Gut inoculation of α-syn PFF increased Lewy body accumulation in the hippocampal dentate gyrus, with heightened microglia and astrocyte activation and worsened non-motor symptoms. Intrastriatal α-syn preformed fibril injection induced motor deficits, reactive glial protein accumulation, and tauopathy in the prefrontal cortex and hippocampus of Gba1 E326K mice. GBA1 deficiency due to the Gba1 E326K mutation exacerbates neuroinflammation and promotes pathogenic α-synuclein transmission, intensifying disease pathology in PD models. This study enhances our understanding of how the Gba1 E326K mutation contributes to neuroinflammation and the spread of pathogenic α-syn in the brain, suggesting new therapeutic strategies for PD and related synucleinopathies.

2.
Sensors (Basel) ; 22(22)2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36433508

RESUMO

Plant diseases are a major cause of reduction in agricultural output, which leads to severe economic losses and unstable food supply. The citrus plant is an economically important fruit crop grown and produced worldwide. However, citrus plants are easily affected by various factors, such as climate change, pests, and diseases, resulting in reduced yield and quality. Advances in computer vision in recent years have been widely used for plant disease detection and classification, providing opportunities for early disease detection, and resulting in improvements in agriculture. Particularly, the early and accurate detection of citrus diseases, which are vulnerable to pests, is very important to prevent the spread of pests and reduce crop damage. Research on citrus pest disease is ongoing, but it is difficult to apply research results to cultivation owing to a lack of datasets for research and limited types of pests. In this study, we built a dataset by self-collecting a total of 20,000 citrus pest images, including fruits and leaves, from actual cultivation sites. The constructed dataset was trained, verified, and tested using a model that had undergone five transfer learning steps. All models used in the experiment had an average accuracy of 97% or more and an average f1 score of 96% or more. We built a web application server using the EfficientNet-b0 model, which exhibited the best performance among the five learning models. The built web application tested citrus pest disease using image samples collected from websites other than the self-collected image samples and prepared data, and both samples correctly classified the disease. The citrus pest automatic diagnosis web system using the model proposed in this study plays a useful auxiliary role in recognizing and classifying citrus diseases. This can, in turn, help improve the overall quality of citrus fruits.


Assuntos
Citrus , Aprendizado Profundo , Doenças das Plantas , Agricultura , Frutas
3.
Proc Natl Acad Sci U S A ; 115(4): 798-803, 2018 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-29311330

RESUMO

Accumulating evidence suggests that α-synuclein (α-syn) occurs physiologically as a helically folded tetramer that resists aggregation. However, the mechanisms underlying the regulation of formation of α-syn tetramers are still mostly unknown. Cellular membrane lipids are thought to play an important role in the regulation of α-syn tetramer formation. Since glucocerebrosidase 1 (GBA1) deficiency contributes to the aggregation of α-syn and leads to changes in neuronal glycosphingolipids (GSLs) including gangliosides, we hypothesized that GBA1 deficiency may affect the formation of α-syn tetramers. Here, we show that accumulation of GSLs due to GBA1 deficiency decreases α-syn tetramers and related multimers and increases α-syn monomers in CRISPR-GBA1 knockout (KO) SH-SY5Y cells. Moreover, α-syn tetramers and related multimers are decreased in N370S GBA1 Parkinson's disease (PD) induced pluripotent stem cell (iPSC)-derived human dopaminergic (hDA) neurons and murine neurons carrying the heterozygous L444P GBA1 mutation. Treatment with miglustat to reduce GSL accumulation and overexpression of GBA1 to augment GBA1 activity reverse the destabilization of α-syn tetramers and protect against α-syn preformed fibril-induced toxicity in hDA neurons. Taken together, these studies provide mechanistic insights into how GBA1 regulates the transition from monomeric α-syn to α-syn tetramers and multimers and suggest unique therapeutic opportunities for PD and dementia with Lewy bodies.


Assuntos
Neurônios Dopaminérgicos/metabolismo , Glucosilceramidase/deficiência , Glicoesfingolipídeos/metabolismo , Doença de Parkinson/metabolismo , alfa-Sinucleína/metabolismo , 1-Desoxinojirimicina/análogos & derivados , Linhagem Celular Tumoral , Glucosilceramidase/genética , Humanos , Multimerização Proteica
4.
Hum Mol Genet ; 27(13): 2344-2356, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29897434

RESUMO

Accumulating evidence suggests that the non-receptor tyrosine kinase c-Abl plays an important role in the progression of Parkinson's disease (PD) and c-Abl inhibition could be neuroprotective in PD and related α-synucleinopathies. Nilotinib, a c-Abl inhibitor, has shown improved motor and cognitive symptoms in PD patients. However, issues concerning blood-brain barrier (BBB) penetration, lack of selectivity and safety still remain. Radotinib HCl is a selective Bcr-Abl kinase inhibitor that not only effectively access the brain, but also exhibits greater pharmacokinetic properties and safety profiles compared to Nilotinib and other c-Abl inhibitors. Here, we show the neuroprotective efficacy of Radotinib HCl, a brain penetrant c-Abl inhibitor, in a pre-clinical model of PD. Importantly, in vitro studies demonstrate that the treatment of Radotinib HCl protects the α-synuclein preformed fibrils (PFF)-induced neuronal toxicity, reduces the α-synuclein PFF-induced Lewy bodies (LB)/Lewy neurites (LN)-like pathology and inhibits the α-synuclein PFF-induced c-Abl activation in primary cortical neurons. Furthermore, administration of Radotinib HCl inhibits c-Abl activation and prevents dopaminergic neuron loss, neuroinflammation and behavioral deficits following α-synuclein PFF-induced toxicity in vivo. Taken together, our findings indicate that Radotinib HCl has beneficial neuroprotective effects in PD and provides an evidence that selective and brain permeable c-Abl inhibitors can be potential therapeutic agents for the treatment of PD and related α-synucleinopathies.


Assuntos
Encéfalo/efeitos dos fármacos , Degeneração Neural/tratamento farmacológico , Doença de Parkinson/tratamento farmacológico , Proteínas Proto-Oncogênicas c-abl/antagonistas & inibidores , alfa-Sinucleína/genética , Animais , Barreira Hematoencefálica , Encéfalo/metabolismo , Modelos Animais de Doenças , Dopamina/metabolismo , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/patologia , Humanos , Corpos de Lewy/efeitos dos fármacos , Camundongos , Degeneração Neural/genética , Fármacos Neuroprotetores/administração & dosagem , Doença de Parkinson/genética , Doença de Parkinson/patologia , Proteínas Proto-Oncogênicas c-abl/genética , Pirimidinas/administração & dosagem , Sesquiterpenos/administração & dosagem
5.
Brain ; 142(8): 2380-2401, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31237944

RESUMO

α-Synuclein misfolding and aggregation plays a major role in the pathogenesis of Parkinson's disease. Although loss of function mutations in the ubiquitin ligase, parkin, cause autosomal recessive Parkinson's disease, there is evidence that parkin is inactivated in sporadic Parkinson's disease. Whether parkin inactivation is a driver of neurodegeneration in sporadic Parkinson's disease or a mere spectator is unknown. Here we show that parkin in inactivated through c-Abelson kinase phosphorylation of parkin in three α-synuclein-induced models of neurodegeneration. This results in the accumulation of parkin interacting substrate protein (zinc finger protein 746) and aminoacyl tRNA synthetase complex interacting multifunctional protein 2 with increased parkin interacting substrate protein levels playing a critical role in α-synuclein-induced neurodegeneration, since knockout of parkin interacting substrate protein attenuates the degenerative process. Thus, accumulation of parkin interacting substrate protein links parkin inactivation and α-synuclein in a common pathogenic neurodegenerative pathway relevant to both sporadic and familial forms Parkinson's disease. Thus, suppression of parkin interacting substrate protein could be a potential therapeutic strategy to halt the progression of Parkinson's disease and related α-synucleinopathies.


Assuntos
Doença de Parkinson/metabolismo , Proteínas Repressoras/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , alfa-Sinucleína/metabolismo , Animais , Feminino , Humanos , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Doença de Parkinson/patologia
6.
J Neurochem ; 149(3): 413-426, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30488434

RESUMO

Misfolded proteins with abnormal polyglutamine (polyQ) expansion cause neurodegenerative disorders, including Huntington's disease. Recently, it was found that polyQ aggregates accumulate as a result of vaccinia-related kinase 2 (VRK2)-mediated degradation of TCP-1 ring complex (TRiC)/chaperonin-containing TCP-1 (CCT), which has an essential role in the prevention of polyQ protein aggregation and cytotoxicity. The levels of VRK2 are known to be much higher in actively proliferating cells but are maintained at a low level in the brain via an unknown mechanism. Here, we found that basal levels of neuronal cell-specific VRK2 mRNA are maintained by post-transcriptional, rather than transcriptional, regulation. Moreover, heterogeneous nuclear ribonucleoprotein Q (HNRNP Q) specifically binds to the 3'untranslated region of VRK2 mRNA in neuronal cells to reduce the mRNA stability. As a result, we found a dramatic decrease in CCT4 protein levels in response to a reduction in HNRNP Q levels, which was followed by an increase in polyQ aggregation in human neuroblastoma cells and mouse cortical neurons. Taken together, these results provide new insights into how neuronal HNRNP Q decreases VRK2 mRNA stability and contributes to the prevention of Huntington's disease, while also identifying new prognostic markers of HD.


Assuntos
Regulação da Expressão Gênica/genética , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Proteína Huntingtina/metabolismo , Doença de Huntington/metabolismo , Proteínas Serina-Treonina Quinases/biossíntese , Animais , Encéfalo/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Peptídeos/metabolismo , Processamento Pós-Transcricional do RNA
7.
FASEB J ; 31(6): 2301-2313, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28223337

RESUMO

The dopaminergic system plays an essential role in various functions of the brain, including locomotion, memory, and reward, and the deregulation of dopaminergic signaling as a result of altered functionality of dopamine D2 receptor (DRD2) is implicated in multiple neurologic and psychiatric disorders. Tetraspanin-7 (TSPAN7) is expressed to variable degrees in different tissues, with the highest level in the brain, and multiple mutations in TSPAN7 have been implicated in intellectual disability. Here, we tested the hypothesis that TSPAN7 may be a binding partner of DRD2 that is involved in the regulation of its functional activity. Our results showed that TSPAN7 was associated with DRD2 and reduced its surface expression by enhancing DRD2 internalization. Immunocytochemical analysis revealed that TSPAN7 that resides in the plasma membrane and early and late endosomes promoted internalization of DRD2 and its localization to endosomal compartments of the endocytic pathway. Furthermore, we observed that TSPAN7 deficiency increased surface localization of DRD2 concurrent with the decrease of its endocytosis, regardless of dopamine treatment. Finally, TSPAN7 negatively affects DRD2-mediated signaling. These results disclosed a previously uncharacterized role of TSPAN7 in the regulation of the expression and functional activity of DRD2 by postendocytic trafficking.-Lee, S.-A., Suh, Y., Lee, S., Jeong, J., Kim, S. J., Kim, S. J., Park, S. K. Functional expression of dopamine D2 receptor is regulated by tetraspanin 7-mediated postendocytic trafficking.


Assuntos
Proteínas do Tecido Nervoso/metabolismo , Receptores de Dopamina D2/metabolismo , Tetraspaninas/metabolismo , Animais , Linhagem Celular , Regulação da Expressão Gênica/fisiologia , Humanos , Proteínas do Tecido Nervoso/genética , Isoformas de Proteínas , Transporte Proteico , Receptores de Dopamina D2/genética , Transdução de Sinais , Tetraspaninas/genética
8.
Xenotransplantation ; 22(5): 391-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26381495

RESUMO

BACKGROUND: Nitric oxide (NO) can reduce platelet adhesion and vascular resistance. Tempol can scavenge the reactive oxygen species (ROS) that induce tissue injury. As xenograft rejection attenuates endogenous NO production and generates ROS, we evaluated the potential effect of an NO donor (SIN-1, 3-morpholinosydnonimine) and tempol on hyperacute xenograft dysfunction using an ex vivo porcine lung perfusion model. METHODS: For the evaluation of von Willebrand factor (vWF) secretion, human endothelial cells were stimulated with thrombin. Porcine lungs were perfused with either fresh human whole blood (unmodified control group [n = 4]), SIN-1 (n = 4), or SIN and tempol (n = 4). RESULTS: SIN-1 and tempol significantly inhibited vWF secretion from endothelial cells in vitro. However, they did not suppress xenogeneic complement activation. In an ex vivo pulmonary perfusion model, SIN-1 improved pulmonary xenograft function by reducing pulmonary vascular resistance (PVR), inhibiting complement activation, and inhibiting thrombin generation. Combined treatment with tempol and SIN-1 potentiated PVR reduction, but slightly enhanced complement activation. CONCLUSIONS: An NO donor is expected to improve pulmonary xenograft function through inhibition of vWF secretion, vasoconstriction, thrombin generation, and indirectly through inhibition of complement activation. The additional effects of tempol on an NO donor were not considered significant in an ex vivo xenograft system.


Assuntos
Rejeição de Enxerto/prevenção & controle , Transplante de Pulmão , Doadores de Óxido Nítrico/uso terapêutico , Substâncias Protetoras/uso terapêutico , Transplante Heterólogo , Animais , Linhagem Celular , Óxidos N-Cíclicos/uso terapêutico , Quimioterapia Combinada , Humanos , Molsidomina/análogos & derivados , Molsidomina/uso terapêutico , Perfusão , Marcadores de Spin , Suínos , Resultado do Tratamento
9.
Biotechnol Lett ; 37(5): 1101-6, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25700814

RESUMO

OBJECTIVE: To produce 10-ketostearic acid from oleic acid. RESULTS: Oleic acid was converted to 10-ketostearic acid by a recombinant Corynebacterium glutamicum ATCC 13032 expressing oleate hydratase from Stenotrophomonas maltophilia and a secondary alcohol dehydrogenase from Micrococcus luteus under the control of a synthetic constitutive promoter. Optimal conditions for 10-ketostearic acid production were pH 7.5 and 30 °C with 5 g cells l(-1) and 2.5 g oleic acid l(-1). Under these conditions, the cells produced 1.96 g 10-ketostearic acid l(-1) from oleic acid in 6 h, with a conversion yield of 78 % (w) and a maximum volumetric productivity of 1.67 g l(-1) h(-1). CONCLUSION: This is the first report of 10-ketostearic acid production using a recombinant C. glutamicum.


Assuntos
Oxirredutases do Álcool/metabolismo , Corynebacterium glutamicum/genética , Corynebacterium glutamicum/metabolismo , Hidroliases/metabolismo , Ácido Oleico/metabolismo , Ácidos Esteáricos/metabolismo , Oxirredutases do Álcool/genética , Biotransformação , Corynebacterium glutamicum/enzimologia , Hidroliases/genética , Concentração de Íons de Hidrogênio , Micrococcus luteus/enzimologia , Micrococcus luteus/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Stenotrophomonas maltophilia/enzimologia , Stenotrophomonas maltophilia/genética , Temperatura
10.
J Biol Chem ; 288(52): 36878-89, 2013 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-24235147

RESUMO

Circadian rhythm is a biological rhythm governing physiology and behavior with a period of ∼24 h. At the molecular level, circadian output is controlled by a molecular clock composed of positive and negative feedback loops in transcriptional and post-translational processes. CLOCK is a transcription factor known as a central component of the molecular clock feedback loops generating circadian oscillation. Although CLOCK is known to undergo multiple post-translational modifications, the knowledge of their entities remains limited. Cyclin-dependent kinase 5 (Cdk5) is a proline-directed serine-threonine kinase that is involved in various neuronal processes. Here, we report that Cdk5 is a novel regulator of CLOCK protein. Cdk5 phosphorylates CLOCK at the Thr-451 and Thr-461 residues in association with transcriptional activation of CLOCK. The Cdk5-dependent regulation of CLOCK function is mediated by alterations of its stability and subcellular distribution. These results suggest that Cdk5 is a novel regulatory component of the core molecular clock machinery.


Assuntos
Proteínas CLOCK/metabolismo , Quinase 5 Dependente de Ciclina/metabolismo , Processamento de Proteína Pós-Traducional/fisiologia , Ativação Transcricional/fisiologia , Animais , Proteínas CLOCK/genética , Quinase 5 Dependente de Ciclina/genética , Células HEK293 , Humanos , Camundongos , Células NIH 3T3 , Fosforilação/fisiologia , Estabilidade Proteica , Transporte Proteico/fisiologia , Treonina/genética , Treonina/metabolismo
11.
In Vivo ; 38(1): 226-234, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38148068

RESUMO

BACKGROUND/AIM: Chronic kidney disease (CKD) is one of the most common causes of mortality in wild non-domestic felidae. The molecular mechanism regulating renal fibrosis in nephropathy is not fully understood especially in the felidae. This study aimed to elucidate senescence marker protein 30 (SMP30) expression patterns and its relationship with epithelial-mesenchymal transition (EMT) by immunostaining in two necropsied Siberian tigers (Panthera tigris altaica) with CKD. MATERIALS AND METHODS: Two kidney samples from male Siberian tigers were fixed and tissue sections were stained for histopathological assay. RESULTS: In CKD, renal tubular epithelial cells lost their tubular structures surrounded by severe interstitial fibrosis and were detached from the basement membrane. These damaged cells resembled the morphology of mesenchymal cells and showed much lower SMP30 expression compared with intact tubular epithelial cells. These cells also expressed vimentin, which is specifically expressed by mesenchymal cells, and through double staining, it was observed that vimentin was expressed in the tubular epithelial cells where SMP30 was not expressed. In addition, double-positive expression of pan-cytokeratin (pan-CK) and vimentin was found in damaged epithelial cells with mesenchymal features. CONCLUSION: We demonstrated possible evidence to understand the role of SMP30 as a new pivotal factor and the possibility of decreased SMP30 as a potential indicator of EMT at the end stage of CKD.


Assuntos
Felidae , Insuficiência Renal Crônica , Tigres , Animais , Masculino , Humanos , Vimentina , Rim , Insuficiência Renal Crônica/genética , Transição Epitelial-Mesenquimal/genética , Fibrose
12.
Mater Today Bio ; 23: 100838, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38033369

RESUMO

Polymer-based lab-on-a-disc (LoaD) devices for isolating ribonucleic acid (RNA) from whole blood samples have gained considerable attention for accurate biomedical analysis and point-of-care diagnostics. However, the mass production of these devices remains challenging in manufacturing cost and sustainability, primarily due to the utilization of a laser cutter or router computer numerical control (CNC) machine for engraving and cutting plastics in the conventional prototyping process. Herein, we reported the first energy-efficient room-temperature printing-imprinting integrated roll-to-roll manufacturing platform for mass production of a polydimethylsiloxane (PDMS)-based LoaD to on-site isolate ribonucleic acid (RNA) from undiluted blood samples. We significantly reduced energy consumption and eliminated thermal expansion variations between the mold, substrate, and resists by accelerating the PDMS curing time to less than 10 min at room temperature without using heat or ultraviolet radiation. The additive manufacturing technology was applied to fabricate a multi-depth flexible polymer mold that integrated macro (2 mm) and micro-sized (500 µm) features, which overcomes the economic and environmental challenges of conventional molding techniques. Our integrated R2R platform was enabled to print adhesion-promoting films at the first printing unit and continuously in-line imprint with a high replication accuracy (99%) for high-volume manufacturing of a new centrifugal microfluidic chip with an enhancement of mixing performance by integrating an efficient mixing chamber and serpentine micromixer. This research paved the way for scalable green manufacturing of large-volume polymer-based microfluidic devices, often required in real-world sample-driven analytical systems for clinical bioanalysis.

13.
bioRxiv ; 2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-37745332

RESUMO

Mutations in the GBA1 gene have been identified as a prevalent genetic risk factor for Parkinson's disease (PD). GBA1 mutations impair enzymatic activity, leading to lysosomal dysfunction and elevated levels of α-synuclein (α-syn). While most research has primarily focused on GBA1's role in promoting synucleinopathy, emerging evidence suggests that neuroinflammation may be a key pathogenic alteration caused by GBA1 deficiency. To examine the molecular mechanism underlying GBA1 deficiency-mediated neuroinflammation, we generated Gba1 E326K knock-in (KI) mice using the CRISPR/Cas9 technology, which is linked to an increased risk of PD and dementia with Lewy bodies (DLB). In the ventral midbrain and hippocampus of 24-month-old Gba1 E326K KI mice, we found a moderate decline in GBA1 enzymatic activity, a buildup of glucosylceramide, and an increase in microglia density. Furthermore, we observed increased levels of pro-inflammatory cytokines and formation of reactive astrocytes in primary microglia and astrocytes, respectively, cultured from Gba1 E326K KI mice following treatment with pathologic α-syn preformed fibrils (PFF). Additionally, the gut inoculation of α-syn PFF in Gba1 E326K KI mice significantly enhanced the accumulation of Lewy bodies in the dentate gyrus of the hippocampus, accompanied by aggravated neuroinflammation and exacerbated non-motor symptoms. This research significantly enhances our understanding of the Gba1 E326K mutation's involvement in neuroinflammation and the cell-to-cell transmission of pathogenic α-syn in the brain, thereby opening new therapeutic avenues.

14.
MRS Commun ; 13(6): 1053-1062, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38818251

RESUMO

The ability to govern particle assembly in an evaporative-driven additive manufacturing (AM) can realize multi-scale features fundamental to creating printed electronics. However, existing techniques remain challenging and often require templates or contaminating solutes. We explore the control of particle deposition in 3D-printed colloids by diffusiophoresis, a previously unexplored mechanism in multi-scale AM. Diffusiophoresis can introduce spontaneous phoretic particle motion by establishing local solute concentration gradients. We show that diffusiophoresis can play a dominant role in complex evaporative-driven particle assembly, enabling a fundamentally new and versatile control of particle deposition in a multi-scale AM process.

15.
Nanomaterials (Basel) ; 12(15)2022 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-35957030

RESUMO

The uneven deposition at the edges of an evaporating droplet, termed the coffee-ring effect, has been extensively studied during the past few decades to better understand the underlying cause, namely the flow dynamics, and the subsequent patterns formed after drying. The non-uniform evaporation rate across the colloidal droplet hampers the formation of a uniform and homogeneous film in printed electronics, rechargeable batteries, etc., and often causes device failures. This review aims to highlight the diverse range of techniques used to alleviate the coffee-ring effect, from classic methods such as adding chemical additives, applying external sources, and manipulating geometrical configurations to recently developed advancements, specifically using bubbles, humidity, confined systems, etc., which do not involve modification of surface, particle or liquid properties. Each of these methodologies mitigates the edge deposition via multi-body interactions, for example, particle-liquid, particle-particle, particle-solid interfaces and particle-flow interactions. The mechanisms behind each of these approaches help to find methods to inhibit the non-uniform film formation, and the corresponding applications have been discussed together with a critical comparison in detail. This review could pave the way for developing inks and processes to apply in functional coatings and printed electronic devices with improved efficiency and device yield.

16.
Micromachines (Basel) ; 13(8)2022 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-36014138

RESUMO

Lab-on-a-CD (LOCD) is gaining importance as a diagnostic platform due to being low-cost, easy-to-use, and portable. During LOCD usage, mixing and reaction are two processes that play an essential role in biochemical applications such as point-of-care diagnosis. In this paper, we numerically and experimentally investigate the effects of the Coriolis and Euler forces in the mixing chamber during the acceleration and deceleration of a rotating disk. The mixing performance is investigated under various conditions that have not been reported, such as rotational condition, chamber aspect ratio at a constant volume, and obstacle arrangement in the chamber. During disk acceleration and deceleration, the Euler force difference in the radial direction causes rotating flows, while the Coriolis force induces perpendicular vortices. Increasing the maximum rotational velocity improves the maximum rotational displacement, resulting in better mixing performance. A longer rotational period increases the interfacial area between solutions and enhances mixing. Mixing performance also improves when there is a substantial difference between Euler forces at the inner and outer radii. Furthermore, adding obstacles in the angular direction also passively promotes or inhibits mixing by configuration. This quantitative investigation provides valuable information for designing and developing high throughput and multiplexed point-of-care LOCDs.

17.
Biomicrofluidics ; 16(4): 044102, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35909647

RESUMO

Systematic evolution of ligands by exponential enrichment (SELEX) is a method that is generally used for developing aptamers, which have arisen the promising alternatives for antibodies. However, conventional SELEX methods have limitations, such as a limited selection of target molecules, time-consuming and complex fabrication processes, and labor-intensive processes, which result in low selection yields. Here, we used (i) graphene oxide (GO)-coated magnetic nanoparticles in the selection process for separation and label-free detection and (ii) a multilayered microfluidic device manufactured using a three-dimensionally printed mold that is equipped with automated control valves to achieve precise fluid flows. The developed on-chip aptamer selection device and GO-coated magnetic nanoparticles were used to screen aptamer candidates for adenosine in eight cycles of the selection process within approximately 2 h for each cycle. Based on results from isothermal titration calorimetry, an aptamer with a dissociation constant of 18.6 ± 1.5 µM was selected. Therefore, the on-chip platform based on GO-coated magnetic nanoparticles provides a novel label-free screening technology for biosensors and micro/nanobiotechnology for achieving high-quality aptamers.

18.
Cells ; 11(24)2022 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-36552734

RESUMO

Non-receptor tyrosine kinase, c-Abl plays a role in the pathogenesis of several neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. Here, we found that TDP-43, which was one of the main proteins comprising pathological deposits in amyotrophic lateral sclerosis (ALS), is a novel substrate for c-Abl. The phosphorylation of tyrosine 43 of TDP-43 by c-Abl led to increased TDP-43 levels in the cytoplasm and increased the formation of G3BP1-positive stress granules in SH-SY5Y cells. The kinase-dead mutant of c-Abl had no effect on the cytoplasmic localization of TDP-43. The expression of phosphor-mimetic mutant Y43E of TDP-43 in primary cortical neurons accumulated the neurite granule. Furthermore, the phosphorylation of TDP-43 at tyrosine 43 by c-Abl promoted the aggregation of TDP-43 and increased neuronal cell death in primary cortical neurons, but not in c-Abl-deficient primary cortical neurons. Identification of c-Abl as the kinase of TDP43 provides new insight into the pathogenesis of ALS.


Assuntos
Esclerose Lateral Amiotrófica , Proteínas Proto-Oncogênicas c-abl , Humanos , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , DNA Helicases/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Neuroblastoma , Fosforilação , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , RNA Helicases/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Proteínas Proto-Oncogênicas c-abl/genética , Proteínas Proto-Oncogênicas c-abl/metabolismo , Tirosina/metabolismo
19.
Prog Neurobiol ; 198: 101915, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32966834

RESUMO

While positive regulators of hippocampal long-term potentiation (LTP) have extensively been investigated, relatively little is known about the inhibitory regulators of LTP. We previously reported that Cyclin Y (CCNY), a member of cyclin family generally known to function in proliferating cells, is a novel postsynaptic protein that serves as a negative regulator of functional LTP. However, whether CCNY plays a role in structural LTP, which is mechanistically linked to functional LTP, and which mechanisms are involved in the CCNY-mediated suppression of LTP at the molecular level remain elusive. Here, we report that CCNY negatively regulates the plasticity-induced changes in spine morphology through the control of actin dynamics. We observed that CCNY directly binds to filamentous actin and interferes with LTP-induced actin polymerization as well as depolymerization by blocking the activation of cofilin, an actin-depolymerizing factor, thus resulting in less plastic spines and the impairment of structural LTP. These data suggest that CCNY acts as an inhibitory regulator for both structural and functional LTP by modulating actin dynamics through the cofilin-actin pathway. Collectively, our findings provide a mechanistic insight into the inhibitory modulation of hippocampal LTP by CCNY, highlighting a novel function of a cyclin family protein in non-proliferating neuronal cells.


Assuntos
Plasticidade Neuronal , Fatores de Despolimerização de Actina , Actinas , Ciclinas , Proteínas dos Microfilamentos , Sinapses
20.
J Med Chem ; 64(20): 15091-15110, 2021 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-34583507

RESUMO

Parkinson's disease (PD) is a progressive neurodegenerative disorder that affects movement. The nonreceptor tyrosine kinase c-Abl has shown a potential role in the progression of PD. As such, c-Abl inhibition is a promising candidate for neuroprotection in PD and α-synucleinopathies. Compound 5 is a newly synthesized blood-brain barrier penetrant c-Abl inhibitor with higher efficacy than existing inhibitors. The objective of the current study was to demonstrate the neuroprotective effects of compound 5 on the α-synuclein preformed fibril (α-syn PFF) mouse model of PD. Compound 5 significantly reduced neurotoxicity, activation of c-Abl, and Lewy body pathology caused by α-syn PFF in cortical neurons. Additionally, compound 5 markedly ameliorated the loss of dopaminergic neurons, c-Abl activation, Lewy body pathology, neuroinflammatory responses, and behavioral deficits induced by α-syn PFF injection in vivo. Taken together, these results suggest that compound 5 could be a pharmaceutical agent to prevent the progression of PD and α-synucleinopathies.


Assuntos
Fármacos Neuroprotetores/farmacologia , Doença de Parkinson/tratamento farmacológico , Proteínas Proto-Oncogênicas c-abl/antagonistas & inibidores , Relação Dose-Resposta a Droga , Humanos , Modelos Moleculares , Estrutura Molecular , Fármacos Neuroprotetores/química , Doença de Parkinson/metabolismo , Proteínas Proto-Oncogênicas c-abl/metabolismo , Relação Estrutura-Atividade
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