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1.
J Korean Med Sci ; 35(38): e343, 2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-32989935

RESUMO

BACKGROUND: Observational studies of the ongoing coronavirus disease 2019 (COVID-19) outbreak suggest that a 'cytokine storm' is involved in the pathogenesis of severe illness. However, the molecular mechanisms underlying the altered pathological inflammation in COVID-19 are largely unknown. We report here that toll-like receptor (TLR) 4-mediated inflammatory signaling molecules are upregulated in peripheral blood mononuclear cells (PBMCs) from COVID-19 patients, compared with healthy controls (HC). METHODS: A total of 48 subjects including 28 COVID-19 patients (8 severe/critical vs. 20 mild/moderate cases) admitted to Chungnam National University Hospital, and age/sex-matched 20 HC were enrolled in this study. PBMCs from the subjects were processed for nCounter Human Immunology gene expression assay to analyze the immune related transcriptome profiles. Recombinant proteins of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) were used to stimulate the PBMCs and monocyte-derived macrophages, and real-time polymerase chain reaction was performed to quantify the mRNA expressions of the pro-inflammatory cytokines/chemokines. RESULTS: Among the most highly increased inflammatory mediators in severe/critically ill patients, S100A9, an alarmin and TLR4 ligand, was found as a noteworthy biomarker, because it inversely correlated with the serum albumin levels. We also observed that recombinant S2 and nucleocapsid proteins of SARS-CoV-2 significantly increased pro-inflammatory cytokines/chemokines and S100A9 in human primary PBMCs. CONCLUSION: These data support a link between TLR4 signaling and pathological inflammation during COVID-19 and contribute to develop therapeutic approaches through targeting TLR4-mediated inflammation.


Assuntos
Bacteriemia/etiologia , Betacoronavirus , Infecções por Coronavirus/imunologia , Inflamação/etiologia , Pneumonia Viral/imunologia , Sepse/etiologia , Receptor 4 Toll-Like/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Transdução de Sinais/fisiologia , Regulação para Cima
2.
PLoS One ; 15(8): e0238316, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866201

RESUMO

BACKGROUND: Perinatally HIV-infected children on anti-retroviral treatment (ART) are reported to have metabolic abnormalities such as dyslipidemia, lipodystrophy, and insulin resistance which potentially increase the risk of diabetes, kidney, liver and cardiovascular disease. OBJECTIVE: To elucidate HIV-mediated metabolic complications that sustain even during ART in perinatally HIV-infected children. METHOD: We have carried out metabolic profiling of the plasma of treatment-naïve and ART-suppressed perinatally HIV-infected children and uninfected controls using 1H nuclear magnetic resonance (NMR) spectroscopy followed by statistical analysis and annotation. RESULT: Validated multivariate analysis showed clear distinction among our study groups. Our results showed elevated levels of lactate, glucose, phosphoenolpyruvic acid, propionic acid, 2-ketobutyric acid and tricarboxylic acid (TCA) cycle metabolites in untreated HIV-infected children compared to uninfected controls. ART normalized the levels of several metabolites, however the level of lactate, phosphoenolpyruvic acid, oxoglutaric acid, oxaloacetic acid, myoinositol and glutamine remained upregulated despite ART in HIV-infected children. Pathway analysis revealed perturbed propanoate metabolism, amino acid metabolism, glycolysis and TCA cycle in untreated and ART-suppressed HIV-infected children. CONCLUSION: Developing therapeutic strategies targeting metabolic abnormalities may be beneficial for preventing diabetes, cardiovascular disease or other associated complications in perinatally HIV-infected children.


Assuntos
Infecções por HIV/metabolismo , Plasma/metabolismo , Antirretrovirais/uso terapêutico , Criança , Estudos Transversais , Feminino , Infecções por HIV/tratamento farmacológico , Humanos , Espectroscopia de Ressonância Magnética/métodos , Masculino , Metaboloma/fisiologia , Metabolômica/métodos , Projetos Piloto , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
3.
Nat Commun ; 11(1): 4855, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978390

RESUMO

The atypical chemokine receptor 3 (ACKR3) plays a pivotal role in directing the migration of various cellular populations and its over-expression in tumors promotes cell proliferation and invasiveness. The intracellular signaling pathways transducing ACKR3-dependent effects remain poorly characterized, an issue we addressed by identifying the interactome of ACKR3. Here, we report that recombinant ACKR3 expressed in HEK293T cells recruits the gap junction protein Connexin 43 (Cx43). Cx43 and ACKR3 are co-expressed in mouse brain astrocytes and human glioblastoma cells and form a complex in embryonic mouse brain. Functional in vitro studies show enhanced ACKR3 interaction with Cx43 upon ACKR3 agonist stimulation. Furthermore, ACKR3 activation promotes ß-arrestin2- and dynamin-dependent Cx43 internalization to inhibit gap junctional intercellular communication in primary astrocytes. These results demonstrate a functional link between ACKR3 and gap junctions that might be of pathophysiological relevance.


Assuntos
Astrócitos/metabolismo , Comunicação Celular/fisiologia , Conexina 43/metabolismo , Junções Comunicantes/patologia , Receptores CXCR/metabolismo , Animais , Proliferação de Células , Conexina 43/efeitos dos fármacos , Conexinas/metabolismo , Técnicas de Introdução de Genes , Glioblastoma/metabolismo , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Domínios e Motivos de Interação entre Proteínas , Receptores CXCR/agonistas , Receptores CXCR/genética , Transdução de Sinais/fisiologia
4.
PLoS Comput Biol ; 16(9): e1008202, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32925922

RESUMO

Hydrogen peroxide (H2O2) promotes a range of phenotypes depending on its intracellular concentration and dosing kinetics, including cell death. While this qualitative relationship has been well established, the quantitative and mechanistic aspects of H2O2 signaling are still being elucidated. Mitochondria, a putative source of intracellular H2O2, have recently been demonstrated to be particularly vulnerable to localized H2O2 perturbations, eliciting a dramatic cell death response in comparison to similar cytosolic perturbations. We sought to improve our dynamic and mechanistic understanding of the mitochondrial H2O2 reaction network in HeLa cells by creating a kinetic model of this system and using it to explore basal and perturbed conditions. The model uses the most current quantitative proteomic and kinetic data available to predict reaction rates and steady-state concentrations of H2O2 and its reaction partners within individual mitochondria. Time scales ranging from milliseconds to one hour were simulated. We predict that basal, steady-state mitochondrial H2O2 will be in the low nM range (2-4 nM) and will be inversely dependent on the total pool of peroxiredoxin-3 (Prx3). Neglecting efflux of H2O2 to the cytosol, the mitochondrial reaction network is expected to control perturbations well up to H2O2 generation rates ~50 µM/s (0.25 nmol/mg-protein/s), above which point the Prx3 system would be expected to collapse. Comparison of these results with redox Western blots of Prx3 and Prx2 oxidation states demonstrated reasonable trend agreement at short times (≤ 15 min) for a range of experimentally perturbed H2O2 generation rates. At longer times, substantial efflux of H2O2 from the mitochondria to the cytosol was evidenced by peroxiredoxin-2 (Prx2) oxidation, and Prx3 collapse was not observed. A refined model using Monte Carlo parameter sampling was used to explore rates of H2O2 efflux that could reconcile model predictions of Prx3 oxidation states with the experimental observations.


Assuntos
Peróxido de Hidrogênio/metabolismo , Mitocôndrias/metabolismo , Modelos Biológicos , Neoplasias/metabolismo , Biologia Computacional , Citosol/química , Citosol/metabolismo , Células HeLa , Humanos , Cinética , Mitocôndrias/química , Neoplasias/química , Espécies Reativas de Oxigênio/química , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/fisiologia
5.
Clin Sci (Lond) ; 134(16): 2137-2160, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32820801

RESUMO

The highly infective coronavirus disease 19 (COVID-19) is caused by a novel strain of coronaviruses - the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) - discovered in December 2019 in the city of Wuhan (Hubei Province, China). Remarkably, COVID-19 has rapidly spread across all continents and turned into a public health emergency, which was ultimately declared as a pandemic by the World Health Organization (WHO) in early 2020. SARS-CoV-2 presents similar aspects to other members of the coronavirus family, mainly regarding its genome, protein structure and intracellular mechanisms, that may translate into mild (or even asymptomatic) to severe infectious conditions. Although the mechanistic features underlying the COVID-19 progression have not been fully clarified, current evidence have suggested that SARS-CoV-2 may primarily behave as other ß-coronavirus members. To better understand the development and transmission of COVID-19, unveiling the signaling pathways that may be impacted by SARS-CoV-2 infection, at the molecular and cellular levels, is of crucial importance. In this review, we present the main aspects related to the origin, classification, etiology and clinical impact of SARS-CoV-2. Specifically, here we describe the potential mechanisms of cellular interaction and signaling pathways, elicited by functional receptors, in major targeted tissues/organs from the respiratory, gastrointestinal (GI), cardiovascular, renal, and nervous systems. Furthermore, the potential involvement of these signaling pathways in evoking the onset and progression of COVID-19 symptoms in these organ systems are presently discussed. A brief description of future perspectives related to potential COVID-19 treatments is also highlighted.


Assuntos
Betacoronavirus/patogenicidade , Infecções por Coronavirus/virologia , Sistema Nervoso/virologia , Pneumonia Viral/virologia , Transdução de Sinais/fisiologia , China , Infecções por Coronavirus/transmissão , Humanos , Pandemias , Pneumonia Viral/transmissão
6.
Nat Commun ; 11(1): 4112, 2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32807784

RESUMO

Macropinocytosis is essential for myeloid cells to survey their environment and for growth of RAS-transformed cancer cells. Several growth factors and inflammatory stimuli are known to induce macropinocytosis, but its endogenous inhibitors have remained elusive. Stimulation of Roundabout receptors by Slit ligands inhibits directional migration of many cell types, including immune cells and cancer cells. We report that SLIT2 inhibits macropinocytosis in vitro and in vivo by inducing cytoskeletal changes in macrophages. In mice, SLIT2 attenuates the uptake of muramyl dipeptide, thereby preventing NOD2-dependent activation of NF-κB and consequent secretion of pro-inflammatory chemokine, CXCL1. Conversely, blocking the action of endogenous SLIT2 enhances CXCL1 secretion. SLIT2 also inhibits macropinocytosis in RAS-transformed cancer cells, thereby decreasing their survival in nutrient-deficient conditions which resemble tumor microenvironment. Our results identify SLIT2 as a physiological inhibitor of macropinocytosis and challenge the conventional notion that signals that enhance macropinocytosis negatively regulate cell migration, and vice versa.


Assuntos
Citoesqueleto/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Receptores Imunológicos/metabolismo , Animais , Quimiocina CXCL1/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Peptídeos e Proteínas de Sinalização Intercelular/genética , Macrófagos/metabolismo , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Proteínas do Tecido Nervoso/genética , Fagócitos/metabolismo , Pinocitose/genética , Pinocitose/fisiologia , Receptores Imunológicos/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Proteína rhoA de Ligação ao GTP/metabolismo
7.
Nat Commun ; 11(1): 4115, 2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32807795

RESUMO

The transcription factor STAT3 is frequently activated in human solid and hematological malignancies and remains a challenging therapeutic target with no approved drugs to date. Here, we develop synthetic antibody mimetics, termed monobodies, to interfere with STAT3 signaling. These monobodies are highly selective for STAT3 and bind with nanomolar affinity to the N-terminal and coiled-coil domains. Interactome analysis detects no significant binding to other STATs or additional off-target proteins, confirming their exquisite specificity. Intracellular expression of monobodies fused to VHL, an E3 ubiquitin ligase substrate receptor, results in degradation of endogenous STAT3. The crystal structure of STAT3 in complex with monobody MS3-6 reveals bending of the coiled-coil domain, resulting in diminished DNA binding and nuclear translocation. MS3-6 expression strongly inhibits STAT3-dependent transcriptional activation and disrupts STAT3 interaction with the IL-22 receptor. Therefore, our study establishes innovative tools to interfere with STAT3 signaling by different molecular mechanisms.


Assuntos
Anticorpos/metabolismo , Fator de Transcrição STAT3/metabolismo , Células A549 , Anticorpos/genética , Western Blotting , Calorimetria , Cristalografia por Raios X , Citometria de Fluxo , Polarização de Fluorescência , Imunofluorescência , Humanos , Espectrometria de Massas , Ligação Proteica , Domínios Proteicos/imunologia , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/imunologia , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Biologia Sintética
8.
PLoS Comput Biol ; 16(8): e1008076, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32745094

RESUMO

We consider how a signalling system can act as an information hub by multiplexing information arising from multiple signals. We formally define multiplexing, mathematically characterise which systems can multiplex and how well they can do it. While the results of this paper are theoretical, to motivate the idea of multiplexing, we provide experimental evidence that tentatively suggests that the NF-κB transcription factor can multiplex information about changes in multiple signals. We believe that our theoretical results may resolve the apparent paradox of how a system like NF-κB that regulates cell fate and inflammatory signalling in response to diverse stimuli can appear to have the low information carrying capacity suggested by recent studies on scalar signals. In carrying out our study, we introduce new methods for the analysis of large, nonlinear stochastic dynamic models, and develop computational algorithms that facilitate the calculation of fundamental constructs of information theory such as Kullback-Leibler divergences and sensitivity matrices, and link these methods to a new theory about multiplexing information. We show that many current models such as those of the NF-κB system cannot multiplex effectively and provide models that overcome this limitation using post-transcriptional modifications.


Assuntos
Comunicação Celular/fisiologia , Modelos Biológicos , Transdução de Sinais/fisiologia , Algoritmos , Diferenciação Celular/fisiologia , Linhagem Celular Tumoral , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Regulação da Expressão Gênica , Humanos , Teoria da Informação , NF-kappa B/metabolismo , Análise de Célula Única , Processos Estocásticos
9.
PLoS Comput Biol ; 16(8): e1007966, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32760072

RESUMO

Protein activity is often regulated by ligand binding or by post-translational modifications such as phosphorylation. Moreover, proteins that are regulated in this way often contain multiple ligand binding sites or modification sites, which can operate to create an ultrasensitive dose response. Here, we consider the contribution of the individual modification/binding sites to the activation process, and how their individual values affect the ultrasensitive behavior of the overall system. We use a generalized Monod-Wyman-Changeux (MWC) model that allows for variable conformational free energy contributions from distinct sites, and associate a so-called activation parameter to each site. Our analysis shows that the ultrasensitivity generally increases as the conformational free energy contribution from one or more sites is strengthened. Furthermore, ultrasensitivity depends on the mean of the activation parameters and not on their variability. In some cases, we find that the best way to maximize ultrasensitivity is to make the contribution from all sites as strong as possible. These results provide insights into the performance objectives of multiple modification/binding sites and thus help gain a greater understanding of signaling and its role in diseases.


Assuntos
Sítios de Ligação/fisiologia , Metabolismo Energético/fisiologia , Processamento de Proteína Pós-Traducional/fisiologia , Proteínas , Transdução de Sinais/fisiologia , Ligantes , Modelos Biológicos , Fosforilação/fisiologia , Conformação Proteica , Subunidades Proteicas , Proteínas/química , Proteínas/metabolismo , Termodinâmica
10.
Life Sci ; 258: 118217, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32768575

RESUMO

AIMS: Astrocytes expressing the aquaporin-4 (AQP4) water channel are pathogenic, disease specific immunoglobulins (IgG) found in neuromyelitis optica spectrum disorder (NMOSD), referred to as NMO-IgG, which targets astrocytic AQP4. The interleukin-6 (IL-6) signaling when astrocytes were exposed to NMO-IgG present in the serum of NMOSD patients was evaluated. MAIN METHODS: Serum or human-IgG from NMOSD or healthy controls were exposed to astrocytes. The selectivity and immuno-pathological consequences of Ig binding to surface epitopes were measured by confocal microscopy. Astrocytes were exposed to medium, IL-6, soluble IL-6 receptor (sIL-6R), IL-6 + sIL-6R (IL-6/R), NMO-IgG or control-IgG, NMO-IgG + IL-6/R. The expression of key proteins in IL-6 signaling pathway, IL-6 cytokine and mRNA levels were evaluated by western blotting, enzyme-linked immunosorbent assay and quantitative polymerase chain reaction, respectively. KEY FINDINGS: Serum or NMO-IgG from NMOSD patients both induced the rapid downregulation of AQP4 expression on the surface of astrocytes. Stimulation of astrocytes with NMO-IgG, IL-6/R, and NMO-IgG + IL-6/R resulted in the enhancement of IL-6 mRNA expression. Meanwhile, the exogenous addition of NMO-IgG elicited an inflammatory transcriptional response that involved signaling through the Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) pathway. Inhibition of the IL-6/JAK/STAT3 pathway with the JAK1/2 specific inhibitor, AZD1480, reversed the associated increase of IL-6. SIGNIFICANCE: Our findings suggest that NMO-IgG can stimulate the astrocytic JAK1/2/STAT3-dependent inflammatory response, which represents one of the important events in NMO pathogenesis. Inhibition of the JAK1/2 signaling pathway may be a novel promising therapy for NMOSD.


Assuntos
Astrócitos/metabolismo , Imunoglobulina G/sangue , Interleucina-6/metabolismo , Janus Quinases/metabolismo , Neuromielite Óptica/sangue , Fator de Transcrição STAT3/metabolismo , Adulto , Idoso , Animais , Astrócitos/efeitos dos fármacos , Autoanticorpos/sangue , Autoanticorpos/farmacologia , Células Cultivadas , Feminino , Humanos , Imunoglobulina G/farmacologia , Interleucina-6/agonistas , Masculino , Pessoa de Meia-Idade , Ratos , Ratos Wistar , Fator de Transcrição STAT3/agonistas , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Adulto Jovem
11.
Nat Commun ; 11(1): 3897, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32753587

RESUMO

Lipo-chitooligosaccharides (LCOs) are signaling molecules produced by rhizobial bacteria that trigger the nodulation process in legumes, and by some fungi that also establish symbiotic relationships with plants, notably the arbuscular and ecto mycorrhizal fungi. Here, we show that many other fungi also produce LCOs. We tested 59 species representing most fungal phyla, and found that 53 species produce LCOs that can be detected by functional assays and/or by mass spectroscopy. LCO treatment affects spore germination, branching of hyphae, pseudohyphal growth, and transcription in non-symbiotic fungi from the Ascomycete and Basidiomycete phyla. Our findings suggest that LCO production is common among fungi, and LCOs may function as signals regulating fungal growth and development.


Assuntos
Quitina/análogos & derivados , Quitina/metabolismo , Fungos/crescimento & desenvolvimento , Fungos/metabolismo , Transdução de Sinais/fisiologia , Ascomicetos/crescimento & desenvolvimento , Basidiomycota/crescimento & desenvolvimento , Ecologia , Ácidos Graxos/metabolismo , Micorrizas/fisiologia , Rhizobium/metabolismo , Esporos Fúngicos/crescimento & desenvolvimento , Simbiose/fisiologia
12.
Nat Commun ; 11(1): 4167, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32820177

RESUMO

Muscle regeneration depends on a robust albeit transient inflammatory response. Persistent inflammation is a feature of age-related regenerative deficits, yet the underlying mechanisms are poorly understood. Here, we find inflammatory-related CC-chemokine-receptor 2 (Ccr2) expression in non-hematopoietic myogenic progenitors (MPs) during regeneration. After injury, the expression of Ccr2 in MPs corresponds to the levels of its ligands, the chemokines Ccl2, 7, and 8. We find stimulation of Ccr2-activity inhibits MP fusion and contribution to myofibers. This occurs in association with increases in MAPKp38δ/γ signaling, MyoD phosphorylation, and repression of the terminal myogenic commitment factor Myogenin. High levels of Ccr2-chemokines are a feature of regenerating aged muscle. Correspondingly, deletion of Ccr2 in MPs is necessary for proper fusion into regenerating aged muscle. Finally, opportune Ccr2 inhibition after injury enhances aged regeneration and functional recovery. These results demonstrate that inflammatory-induced activation of Ccr2 signaling in myogenic cells contributes to aged muscle regenerative decline.


Assuntos
Mediadores da Inflamação/metabolismo , Músculo Esquelético/fisiopatologia , Receptores CCR2/metabolismo , Regeneração/fisiologia , Transdução de Sinais/fisiologia , Fatores Etários , Animais , Transplante de Células/métodos , Quimiocina CCL2/metabolismo , Quimiocina CCL7/metabolismo , Quimiocina CCL8/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Desenvolvimento Muscular/genética , Músculo Esquelético/lesões , Músculo Esquelético/metabolismo , Miogenina/genética , Miogenina/metabolismo , Receptores CCR2/genética , Regeneração/genética , Células Satélites de Músculo Esquelético/citologia , Células Satélites de Músculo Esquelético/metabolismo , Células Satélites de Músculo Esquelético/transplante , Transdução de Sinais/genética , Ferimentos e Lesões/genética , Ferimentos e Lesões/fisiopatologia , Ferimentos e Lesões/terapia
13.
Med Sci (Paris) ; 36(8-9): 753-762, 2020.
Artigo em Francês | MEDLINE | ID: mdl-32821052

RESUMO

Macular edema is an increase in volume of the central area of the retina, responsible for visual acuity. Visual symptoms handicap the lives of millions of patients with macular edema secondary to chronic and sometimes acute retinal disease. Proteins that neutralize the vascular endothelial growth factor (VEGF) pathway or glucocorticoids, at the cost of repeated intraocular injections over years, limit visual symptoms. A better understanding of why and how edema forms and how therapeutic molecules exert an anti-edematous effect will help prevent this disabling and blinding retinal complication from occurring.


Assuntos
Edema Macular/etiologia , Edema Macular/terapia , Inibidores da Angiogênese/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Glucocorticoides/uso terapêutico , Humanos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/imunologia , Acuidade Visual/efeitos dos fármacos , Acuidade Visual/fisiologia
14.
PLoS One ; 15(8): e0237709, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32817653

RESUMO

OBJECTIVES: In this paper, we aim to detail the setup of a high spatio-temporal resolution, electrical recording system utilising planar microelectrode arrays with simultaneous optical imaging suitable for evaluating microelectrode performance with a proposed 'performance factor' metric. METHODS: Techniques that would facilitate low noise electrical recordings were coupled with voltage sensitive dyes and neuronal activity was recorded both electrically via a customised amplification system and optically via a high speed CMOS camera. This technique was applied to characterise microelectrode recording performance of gold and poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT/PSS) coated electrodes through traditional signal to noise (SNR) calculations as well as the proposed performance factor. RESULTS: Neuronal activity was simultaneously recorded using both electrical and optical techniques and this activity was confirmed via tetrodotoxin application to inhibit action potential firing. PEDOT/PSS outperformed gold using both measurements, however, the performance factor metric estimated a 3 fold improvement in signal transduction when compared to gold, whereas SNR estimated an 8 fold improvement when compared to gold. CONCLUSION: The design and functionality of a system to record from neurons both electrically, through microelectrode arrays, and optically via voltage sensitive dyes was successfully achieved. SIGNIFICANCE: The high spatiotemporal resolution of both electrical and optical methods will allow for an array of applications such as improved detection of subthreshold synaptic events, validation of spike sorting algorithms and a provides a robust evaluation of extracellular microelectrode performance.


Assuntos
Potenciais de Ação/fisiologia , Eletrodos Implantados , Microeletrodos , Neurônios/fisiologia , Algoritmos , Ouro/química , Humanos , Polímeros/química , Transdução de Sinais/fisiologia
15.
Nat Commun ; 11(1): 4157, 2020 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-32814767

RESUMO

Swarming is a form of collective bacterial motion enabled by flagella on the surface of semi-solid media. Swarming populations exhibit non-genetic or adaptive resistance to antibiotics, despite sustaining considerable cell death. Here, we show that antibiotic-induced death of a sub-population benefits the swarm by enhancing adaptive resistance in the surviving cells. Killed cells release a resistance-enhancing factor that we identify as AcrA, a periplasmic component of RND efflux pumps. The released AcrA interacts on the surface of live cells with an outer membrane component of the efflux pump, TolC, stimulating drug efflux and inducing expression of other efflux pumps. This phenomenon, which we call 'necrosignaling', exists in other Gram-negative and Gram-positive bacteria and displays species-specificity. Given that adaptive resistance is a known incubator for evolving genetic resistance, our findings might be clinically relevant to the rise of multidrug resistance.


Assuntos
Antibacterianos/metabolismo , Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Resistência Microbiana a Medicamentos/fisiologia , Transdução de Sinais/fisiologia , Adaptação Fisiológica/fisiologia , Antibacterianos/farmacologia , Bactérias/classificação , Proteínas da Membrana Bacteriana Externa/metabolismo , Bactérias Gram-Negativas/classificação , Bactérias Gram-Negativas/metabolismo , Bactérias Gram-Positivas/classificação , Bactérias Gram-Positivas/metabolismo , Viabilidade Microbiana/efeitos dos fármacos , Periplasma/metabolismo , Especificidade da Espécie
16.
Life Sci ; 258: 118225, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32771557

RESUMO

AIM: The aim of this study was considering the effects of taurine supplementation with combined aerobic and resistance training (CARE) on myocardial apoptosis and Protein Kinase B (akt) level changes in diabetic rat. MAIN METHODS: Forty male Wistar rats were randomly divided in to 5 groups of 8 animals in each: 1) control, 2) Diabetes Mellitus (DM), 3) DM with taurine supplementation (DM/T), 4) DM with CARE (DM/CARE), and 5) DM with combination of taurine and CARE (DM/T/CARE). DM was induced by injection of streptozotocin (STZ) and nicotine amid (NA) for 2, 3, 4 and 5 groups. Supplement groups received taurine in gavage, 100 mg/kg of body weight, 6 day per weeks, 8 weeks. CARE was performed at maximal speed and 1RM (40-60% of maximum for both). KEY FINDINGS: The results of this study showed that DM significantly increased blood glucose and caspase 3, caspase 9 expressions and apoptosis cells in heart tissue and reduced Akt expression (p < 0.001). However, taurine and CARE interventions significantly decreased apoptosis markers (caspase 3 and caspase 9) and significantly increased Akt in heart of diabetic rats compare to DM groups (p < 0.05). The highest improvement observed in DM/T/CARE group (p < 0.05). SIGNIFICANCE: Based on these results, it seems that the use of taurine with combined aerobic and exercise training minimize the cardiac damage caused by diabetes (especially apoptosis) trough increasing protein kinase Akt expression. This could improve cardiac remodeling after diabetes. However, more research is needed, especially on the human samples.


Assuntos
Apoptose/fisiologia , Diabetes Mellitus Experimental/metabolismo , Miocárdio/metabolismo , Condicionamento Físico Animal/fisiologia , Proteínas Proto-Oncogênicas c-akt/biossíntese , Taurina/administração & dosagem , Animais , Apoptose/efeitos dos fármacos , Terapia Combinada/métodos , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Experimental/terapia , Masculino , Miocárdio/patologia , Condicionamento Físico Animal/tendências , Distribuição Aleatória , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
17.
Nat Commun ; 11(1): 4044, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32792536

RESUMO

A growing number of optogenetic tools have been developed to reversibly control binding between two engineered protein domains. In contrast, relatively few tools confer light-switchable binding to a generic target protein of interest. Such a capability would offer substantial advantages, enabling photoswitchable binding to endogenous target proteins in cells or light-based protein purification in vitro. Here, we report the development of opto-nanobodies (OptoNBs), a versatile class of chimeric photoswitchable proteins whose binding to proteins of interest can be enhanced or inhibited upon blue light illumination. We find that OptoNBs are suitable for a range of applications including reversibly binding to endogenous intracellular targets, modulating signaling pathway activity, and controlling binding to purified protein targets in vitro. This work represents a step towards programmable photoswitchable regulation of a wide variety of target proteins.


Assuntos
Optogenética/métodos , Biologia Sintética/métodos , Animais , Células HEK293 , Humanos , Camundongos , Células NIH 3T3 , Ligação Proteica , Transporte Proteico/fisiologia , Transdução de Sinais/fisiologia
18.
Am J Med Sci ; 360(3): 279-286, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32829780

RESUMO

BACKGROUND: The essential role of 6-phosphogluconate dehydrogenase (6PGD), the enzyme catalyzing the oxidative pentose phosphate pathway, in tumor growth and metabolism has garnered attention in recent years. In this work, we are the first to demonstrate that aberrant activation of 6PGD is a feature in renal cell carcinoma (RCC) and is critically involved in renal carcinogenesis and chemo- and immuno-resistance. MATERIALS AND METHODS: 6PGD expression and activity were systematically analyzed in normal and malignant renal cells and tissues. The roles of 6PGD and its downstream mechanism were investigated using gain-of-function and loss-of-function approaches. RESULTS: 6PGD expression and enzyme activity were increased in RCC cells and patients' samples. Activation of 6PGD via gain-of-function approach promoted growth of normal kidney but not RCC cells, and alleviated the efficacy of chemotherapeutic (e.g., 5-FU) and immunotherapeutic (e.g., IFN-α) agents. In contrast, 6PGD inhibition using siRNA knockdown and pharmacological inhibitor physcion augmented the inhibitory effects of 5-FU and IFN-α in RCC. Mechanistic studies demonstrated that 6PGD inhibition activated AMPK signaling, leading to ACC1 enzyme inhibition and reduction of lipid synthesis. In addition, 6PGD inhibition disrupted NADPH and NADH homeostasis in RCC cells as shown by the decreased level of NADPH and NADH, and suppressed SIRT-1 activity. AMPK inhibition by siRNA knockdown reversed the inhibitory effects of physcion, demonstrating that the effect of 6PGD inhibition is AMPK activation dependent. CONCLUSIONS: Our work provides preclinical evidence that 6PGD inhibition may represent a potential therapeutic strategy to augment the efficacy of RCC standard of care drugs.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Carcinoma de Células Renais/terapia , Reprogramação Celular/fisiologia , Neoplasias Renais/terapia , Fosfogluconato Desidrogenase/metabolismo , Transdução de Sinais/fisiologia , Proteínas Quinases Ativadas por AMP/genética , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/patologia , Linhagem Celular , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/fisiologia , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Fluoruracila/uso terapêutico , Técnicas de Silenciamento de Genes , Humanos , Imunoterapia , Interferon-alfa/uso terapêutico , Rim/patologia , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/patologia , NADP/fisiologia , Fosfogluconato Desidrogenase/antagonistas & inibidores , Fosfogluconato Desidrogenase/genética , RNA Interferente Pequeno , Regulação para Cima
19.
Viruses ; 12(7)2020 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-32698440

RESUMO

The coronavirus disease 2019 (COVID-19) outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) affects almost everyone in the world in many ways. We previously predicted antivirals (atazanavir, remdesivir and lopinavir/ritonavir) and non-antiviral drugs (tiotropium and rapamycin) that may inhibit the replication complex of SARS-CoV-2 using our molecular transformer-drug target interaction (MT-DTI) deep-learning-based drug-target affinity prediction model. In this study, we dissected molecular pathways upregulated in SARS-CoV-2-infected normal human bronchial epithelial (NHBE) cells by analyzing an RNA-seq data set with various bioinformatics approaches, such as gene ontology, protein-protein interaction-based network and gene set enrichment analyses. The results indicated that the SARS-CoV-2 infection strongly activates TNF and NFκB-signaling pathways through significant upregulation of the TNF, IL1B, IL6, IL8, NFKB1, NFKB2 and RELB genes. In addition to these pathways, lung fibrosis, keratinization/cornification, rheumatoid arthritis, and negative regulation of interferon-gamma production pathways were also significantly upregulated. We observed that these pathologic features of SARS-CoV-2 are similar to those observed in patients with chronic obstructive pulmonary disease (COPD). Intriguingly, tiotropium, as predicted by MT-DTI, is currently used as a therapeutic intervention in COPD patients. Treatment with tiotropium has been shown to improve pulmonary function by alleviating airway inflammation. Accordingly, a literature search summarized that tiotropium reduced expressions of IL1B, IL6, IL8, RELA, NFKB1 and TNF in vitro or in vivo, and many of them have been known to be deregulated in COPD patients. These results suggest that COVID-19 is similar to an acute mode of COPD caused by the SARS-CoV-2 infection, and therefore tiotropium may be effective for COVID-19 patients.


Assuntos
Betacoronavirus , Infecções por Coronavirus/tratamento farmacológico , Pneumonia Viral/tratamento farmacológico , Brometo de Tiotrópio/uso terapêutico , Transcriptoma , Brônquios/virologia , Infecções por Coronavirus/etiologia , Infecções por Coronavirus/patologia , Células Epiteliais/virologia , Humanos , Pandemias , Pneumonia Viral/etiologia , Pneumonia Viral/patologia , Doença Pulmonar Obstrutiva Crônica/patologia , Transdução de Sinais/fisiologia
20.
Nat Commun ; 11(1): 3639, 2020 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-32686665

RESUMO

Integrated analysis of genomes, transcriptomes, proteomes and drug responses of cancer cell lines (CCLs) is an emerging approach to uncover molecular mechanisms of drug action. We extend this paradigm to measuring proteome activity landscapes by acquiring and integrating quantitative data for 10,000 proteins and 55,000 phosphorylation sites (p-sites) from 125 CCLs. These data are used to contextualize proteins and p-sites and predict drug sensitivity. For example, we find that Progesterone Receptor (PGR) phosphorylation is associated with sensitivity to drugs modulating estrogen signaling such as Raloxifene. We also demonstrate that Adenylate kinase isoenzyme 1 (AK1) inactivates antimetabolites like Cytarabine. Consequently, high AK1 levels correlate with poor survival of Cytarabine-treated acute myeloid leukemia patients, qualifying AK1 as a patient stratification marker and possibly as a drug target. We provide an interactive web application termed ATLANTiC (http://atlantic.proteomics.wzw.tum.de), which enables the community to explore the thousands of novel functional associations generated by this work.


Assuntos
Antineoplásicos/farmacologia , Neoplasias/tratamento farmacológico , Proteoma/metabolismo , Adenilato Quinase/metabolismo , Animais , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Biologia Computacional , Simulação por Computador , Citarabina/metabolismo , Citarabina/farmacologia , Desenvolvimento de Medicamentos , Genômica , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/metabolismo , Neoplasias/metabolismo , Proteoma/genética , Proteômica , Cloridrato de Raloxifeno/metabolismo , Cloridrato de Raloxifeno/farmacologia , Receptores de Progesterona/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
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