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1.
Proc Natl Acad Sci U S A ; 117(36): 22473-22483, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32848055

RESUMO

Human fungal infections may fail to respond to contemporary antifungal therapies in vivo despite in vitro fungal isolate drug susceptibility. Such a discrepancy between in vitro antimicrobial susceptibility and in vivo treatment outcomes is partially explained by microbes adopting a drug-resistant biofilm mode of growth during infection. The filamentous fungal pathogen Aspergillus fumigatus forms biofilms in vivo, and during biofilm growth it has reduced susceptibility to all three classes of contemporary antifungal drugs. Specific features of filamentous fungal biofilms that drive antifungal drug resistance remain largely unknown. In this study, we applied a fluorescence microscopy approach coupled with transcriptional bioreporters to define spatial and temporal oxygen gradients and single-cell metabolic activity within A. fumigatus biofilms. Oxygen gradients inevitably arise during A. fumigatus biofilm maturation and are both critical for, and the result of, A. fumigatus late-stage biofilm architecture. We observe that these self-induced hypoxic microenvironments not only contribute to filamentous fungal biofilm maturation but also drive resistance to antifungal treatment. Decreasing oxygen levels toward the base of A. fumigatus biofilms increases antifungal drug resistance. Our results define a previously unknown mechanistic link between filamentous fungal biofilm physiology and contemporary antifungal drug resistance. Moreover, we demonstrate that drug resistance mediated by dynamic oxygen gradients, found in many bacterial biofilms, also extends to the fungal kingdom. The conservation of hypoxic drug-resistant niches in bacterial and fungal biofilms is thus a promising target for improving antimicrobial therapy efficacy.


Assuntos
Antifúngicos/farmacologia , Aspergillus fumigatus , Biofilmes/efeitos dos fármacos , Microambiente Celular , Farmacorresistência Fúngica , Aspergillus fumigatus/efeitos dos fármacos , Aspergillus fumigatus/fisiologia , Hipóxia Celular , Microambiente Celular/efeitos dos fármacos , Microambiente Celular/fisiologia , Oxigênio/farmacologia
2.
Medicine (Baltimore) ; 99(34): e21821, 2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32846824

RESUMO

BACKGROUND: Traditional Chinese medicine Tongxinluo (TXL) has been widely used to treat coronary artery disease in China, since it could reduce myocardial infarct size and ischemia/reperfusion injury in both non-diabetic and diabetic conditions. It has been shown that TXL could regulate peroxisome proliferator activated receptor-α (PPAR-α), a positive modulator of angiopoietin-like 4 (Angptl4), in diabetic rats. Endothelial junction substructure components, such as VE-cadherin, are involved in the protection of reperfusion injury. Thus, we hypothesized cell-intrinsic and endothelial-specific Angptl4 mediated the protection of TXL on endothelial barrier under high glucose condition against ischemia/reperfusion-injury via PPAR-α pathway. METHODS: Incubated with high glucose medium, the human cardiac microvascular endothelial cells (HCMECs) were then exposed to oxygen-glucose-serum deprivation (2 hours) and restoration (2 hours) stimulation, with or without TXL, insulin, or rhAngptl4 pretreatment. RESULTS: TXL, insulin, and rhAngptl4 had similar protective effects on the endothelial barrier. TXL treatment reversed the endothelial barrier breakdown in HCMECs significantly as identified by decreasing endothelial permeability, upregulating the expression of JAM-A, VE-cadherin, and integrin-α5 and increasing the membrane location of VE-cadherin and integrin-α5, and these effects of TXL were as effective as insulin and rhAngptl4. However, Angptl4 knock-down with small interfering RNA (siRNA) interference and PPAR-α inhibitor MK886 partially abrogated these beneficial effects of TXL. Western blotting also revealed that similar with insulin, TXL upregulated the expression of Angptl4 in HCMECs, which could be inhibited by Angptl4 siRNA or MK886 exposure. TXL treatment increased PPAR-α activity, which could be diminished by MK886 but not by Angptl4 siRNA. CONCLUSION: These data suggest cell-intrinsic and endothelial-specific Angptl4 mediates the protection of TXL against endothelial barrier breakdown during oxygen-glucose-serum deprivation and restoration under high glucose condition partly via the PPAR-α/Angptl4 pathway.


Assuntos
Proteína 4 Semelhante a Angiopoietina/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Células Endoteliais/efeitos dos fármacos , Endotélio/efeitos dos fármacos , Endotélio/fisiopatologia , PPAR alfa/metabolismo , Proteína 4 Semelhante a Angiopoietina/genética , Proteína 4 Semelhante a Angiopoietina/farmacologia , Caderinas/metabolismo , Permeabilidade Capilar , Moléculas de Adesão Celular/metabolismo , Células Cultivadas , Vasos Coronários/citologia , Técnicas de Silenciamento de Genes , Glucose/metabolismo , Glucose/farmacologia , Humanos , Indóis/farmacologia , Insulina/farmacologia , Integrina alfa5/metabolismo , Inibidores de Lipoxigenase/farmacologia , Microvasos/citologia , Oxigênio/metabolismo , Oxigênio/farmacologia , Receptores de Superfície Celular/metabolismo , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais
3.
Science ; 369(6506)2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32820091

RESUMO

Oxygenic photosynthesis is the main process that drives life on earth. It starts with the harvesting of solar photons that, after transformation into electronic excitations, lead to charge separation in the reaction centers of photosystems I and II (PSI and PSII). These photosystems are large, modular pigment-protein complexes that work in series to fuel the formation of carbohydrates, concomitantly producing molecular oxygen. Recent advances in cryo-electron microscopy have enabled the determination of PSI and PSII structures in complex with light-harvesting components called "supercomplexes" from different organisms at near-atomic resolution. Here, we review the structural and spectroscopic aspects of PSI and PSII from plants and algae that directly relate to their light-harvesting properties, with special attention paid to the pathways and efficiency of excitation energy transfer and the regulatory aspects.


Assuntos
Proteínas de Algas/química , Clorófitas/enzimologia , Oxigênio/farmacologia , Fotossíntese , Complexo de Proteína do Fotossistema I/química , Complexo de Proteína do Fotossistema II/química , Microscopia Crioeletrônica , Transferência de Energia , Oxigênio/metabolismo , Fótons
4.
Chemosphere ; 256: 127096, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32447113

RESUMO

Global change and anthropogenic activities have driven marine environment changes dramatically during the past century, and hypoxia, acidification and warming have received much attention recently. Yet, the interactive effects among these stressors on marine organisms are extremely complex and not accurately clarified. Here, we evaluated the combined effects of low dissolved oxygen (DO), low pH and warming on the digestive enzyme activities of the mussel Mytilus coruscus. In this experiment, mussels were exposed to eight treatments, including two degrees of pH (8.1, 7.7), DO (6, 2 mg/l) and temperature (30 °C and 20 °C) for 30 days. Amylase (AMS), lipase (LPS), trypsin (TRY), trehalase (TREH) and lysozyme (LZM) activities were measured in the digestive glands of mussels. All the tested stress conditions showed significant effects on the enzymatic activities. AMS, LPS, TRY, TREH showed throughout decreased trend in their activities due to low pH, low DO, increased temperature and different combinations of these three stressors with time but LZM showed increased and then decreased trend in their activities. Hypoxia and warming showed almost similar effects on the enzymatic activities. PCA showed a positive correlation among all measured biochemical parameters. Therefore, the fitness of mussel is likely impaired by such marine environmental changes and their population may be affected under the global change scenarios.


Assuntos
Aquecimento Global , Mytilus/fisiologia , Amilases , Animais , Digestão , Homeostase/fisiologia , Concentração de Íons de Hidrogênio , Hipóxia , Mytilus/efeitos dos fármacos , Oxigênio/farmacologia , Alimentos Marinhos , Água do Mar/química
5.
Nat Commun ; 11(1): 2099, 2020 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-32350248

RESUMO

Besides pro-inflammatory roles, the ancient cytokine interleukin-17 (IL-17) modulates neural circuit function. We investigate IL-17 signaling in neurons, and the extent it can alter organismal phenotypes. We combine immunoprecipitation and mass spectrometry to biochemically characterize endogenous signaling complexes that function downstream of IL-17 receptors in C. elegans neurons. We identify the paracaspase MALT-1 as a critical output of the pathway. MALT1 mediates signaling from many immune receptors in mammals, but was not previously implicated in IL-17 signaling or nervous system function. C. elegans MALT-1 forms a complex with homologs of Act1 and IRAK and appears to function both as a scaffold and a protease. MALT-1 is expressed broadly in the C. elegans nervous system, and neuronal IL-17-MALT-1 signaling regulates multiple phenotypes, including escape behavior, associative learning, immunity and longevity. Our data suggest MALT1 has an ancient role modulating neural circuit function downstream of IL-17 to remodel physiology and behavior.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/imunologia , Caenorhabditis elegans/fisiologia , Imunidade , Interleucina-17/metabolismo , Longevidade , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa/metabolismo , Neurônios/metabolismo , Animais , Comportamento Animal , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Fluorescência Verde/metabolismo , Imunidade/efeitos dos fármacos , Interneurônios/efeitos dos fármacos , Interneurônios/fisiologia , Longevidade/efeitos dos fármacos , Modelos Biológicos , Neurônios/efeitos dos fármacos , Oxigênio/farmacologia , Transdução de Sinais/efeitos dos fármacos , Frações Subcelulares/metabolismo , Transgenes
6.
Med Sci (Paris) ; 36(4): 382-388, 2020 Apr.
Artigo em Francês | MEDLINE | ID: mdl-32356715

RESUMO

As burden of chronic respiratory diseases is constantly increasing, improving in vitro lung models is essential in order to reproduce as closely as possible the complex pulmonary architecture, responsible for oxygen uptake and carbon dioxide clearance. The study of diseases that affect the respiratory system has benefited from in vitro reconstructions of the respiratory epithelium with inserts in air/liquid interface (2D) or in organoids able to mimic up to the arborescence of the respiratory tree (3D). Recent development in the fields of pluripotent stem cells-derived organoids and genome editing technologies has provided new insights to better understand pulmonary diseases and to find new therapeutic perspectives.


Assuntos
Técnicas de Cultura de Células , Pulmão/citologia , Organoides/citologia , Células Epiteliais Alveolares/citologia , Células Epiteliais Alveolares/fisiologia , Animais , Bioengenharia/métodos , Bioengenharia/tendências , Dióxido de Carbono/farmacologia , Dióxido de Carbono/fisiologia , Técnicas de Cultura de Células/métodos , Técnicas de Cultura de Células/tendências , Células Cultivadas , Edição de Genes/métodos , Edição de Genes/tendências , Humanos , Pulmão/patologia , Pulmão/fisiologia , Modelos Biológicos , Organoides/patologia , Organoides/fisiologia , Oxigênio/farmacologia , Oxigênio/fisiologia , Troca Gasosa Pulmonar/fisiologia , Mucosa Respiratória/citologia , Mucosa Respiratória/efeitos dos fármacos , Tecidos Suporte/química
7.
Nat Commun ; 11(1): 1528, 2020 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-32251294

RESUMO

The occurrence of repetitive genomic changes that provide a selective growth advantage in pluripotent stem cells is of concern for their clinical application. However, the effect of different culture conditions on the underlying mutation rate is unknown. Here we show that the mutation rate in two human embryonic stem cell lines derived and banked for clinical application is low and not substantially affected by culture with Rho Kinase inhibitor, commonly used in their routine maintenance. However, the mutation rate is reduced by >50% in cells cultured under 5% oxygen, when we also found alterations in imprint methylation and reversible DNA hypomethylation. Mutations are evenly distributed across the chromosomes, except for a slight increase on the X-chromosome, and an elevation in intergenic regions suggesting that chromatin structure may affect mutation rate. Overall the results suggest that pluripotent stem cells are not subject to unusually high rates of genetic or epigenetic alterations.


Assuntos
Técnicas de Cultura de Células/métodos , Cromossomos Humanos X/genética , DNA Intergênico/genética , Taxa de Mutação , Células-Tronco Pluripotentes/fisiologia , Linhagem Celular , Meios de Cultura/farmacologia , Metilação de DNA , Análise Mutacional de DNA , Epigênese Genética , Humanos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Oxigênio/química , Oxigênio/farmacologia , Análise de Sequência de RNA , Sequenciamento Completo do Genoma
8.
PLoS One ; 15(4): e0231272, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32271805

RESUMO

Connexin 43 (Cx43) may be important in cell death and survival due to cell-to-cell communication-independent mechanisms. In our previous study, we found that small G protein signaling modulator 3 (SGSM3), a partner of Cx43, contributes to myocardial infarction (MI) in rat hearts. Based on these previous results, we hypothesized that SGSM3 could also play a role in bone marrow-derived rat mesenchymal stem cells (MSCs), which differentiate into cardiomyocytes and/or cells with comparable phenotypes under low oxygen conditions. Cx43 and Cx43-related factor expression profiles were compared between normoxic and hypoxic conditions according to exposure time, and Sgsm3 gene knockdown (KD) using siRNA transfection was performed to validate the interaction between SGSM3 and Cx43 and to determine the roles of SGSM3 in rat MSCs. We identified that SGSM3 interacts with Cx43 in MSCs under different oxygen conditions and that Sgsm3 knockdown inhibits apoptosis and cardiomyocyte differentiation under hypoxic stress. SGSM3/Sgsm3 probably has an effect on MSC survival and thus therapeutic potential in diseased hearts, but SGSM3 may worsen the development of MSC-based therapeutic approaches in regenerative medicine. This study was performed to help us better understand the mechanisms involved in the therapeutic efficacy of MSCs, as well as provide data that could be used pharmacologically.


Assuntos
Apoptose/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Miócitos Cardíacos/metabolismo , Animais , Biomarcadores/metabolismo , Hipóxia Celular/efeitos dos fármacos , Conexina 43/metabolismo , Junções Comunicantes/efeitos dos fármacos , Junções Comunicantes/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Células-Tronco Mesenquimais/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Oxigênio/farmacologia , Ratos Sprague-Dawley , Estresse Fisiológico/efeitos dos fármacos , Fatores de Tempo , Via de Sinalização Wnt/efeitos dos fármacos
10.
Sci Rep ; 10(1): 2744, 2020 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-32066777

RESUMO

Hyperbaric oxygen (HBO) treatment promotes early recovery from muscle injury. Reactive oxygen species (ROS) upregulation is a key mechanism of HBO, which produces high O2 content in tissues through increased dissolution of oxygen at high pressure. Nitric oxide (NO), a type of ROS, generally stabilizes hypoxia-inducible factor (HIF) 1α and stimulates secretion of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) from endothelial cells and macrophages, which then induces angiogenesis. The purpose of the present study was to investigate whether HBO could promote angiogenesis via induction of NO and induce muscle regeneration in contused rat skeletal muscles. The HBO protocol consisted of 2.5 atmospheres absolute (ATA) 100% oxygen for 120 minutes, once a day for 5 consecutive days. We also evaluated the effects of a ROS inhibitor (NAC) or NOS-specific inhibitor (L-NAME) on HBO. HBO significantly increased NO3-, VEGF, and bFGF levels and stabilized HIF1α within 1 day. HBO promoted blood vessel formation at 3-7 days and muscle healing at 5-7 days after contusion. Administration of both NAC and L-NAME before HBO suppressed angiogenesis and muscle regeneration even after HBO. HBO thus promoted angiogenesis and muscle regeneration mainly through generation of NO in the early phase after muscle contusion injury.


Assuntos
Contusões/terapia , Oxigenação Hiperbárica/métodos , Músculo Esquelético/efeitos dos fármacos , Neovascularização Fisiológica/efeitos dos fármacos , Óxido Nítrico/biossíntese , Oxigênio/farmacologia , Acetilcisteína/farmacologia , Indutores da Angiogênese , Animais , Contusões/genética , Contusões/metabolismo , Contusões/patologia , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Fator 2 de Crescimento de Fibroblastos/genética , Fator 2 de Crescimento de Fibroblastos/metabolismo , Regulação da Expressão Gênica , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/agonistas , Óxido Nítrico Sintase Tipo III/antagonistas & inibidores , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/agonistas , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Regeneração/efeitos dos fármacos , Resultado do Tratamento , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
11.
J Biosci ; 452020.
Artigo em Inglês | MEDLINE | ID: mdl-32098914

RESUMO

Ischemia-reperfusion (IR) injury is a major cause of clinical emergencies during and after surgical procedures. Propofol protects the heart from cardiovascular IR injury by inhibiting autophagy. MicroRNAs (miRNAs) participate in anesthetic-regulated cardiovascular injury. MiR-20b-5p targets unc-51-like autophagy activating kinase 1 (ULK1). Its role in propofol-modulated cardiovascular IR injury remains unclear, however. In this study, we used an in vitro model of hypoxia-reoxygenation (HR)-induced injury to human umbilical vein endothelial cells (HUVECs) to determine the protective effect of miR-20b-5p in cells preconditioned with propofol. We found that miR-20b-5p was significantly higher and ULK1 was lower in propofol-preconditioned HUVECs with HR injury than in HUVECs with HR injury only. Additionally, miR-20b-5p overexpression increased cell viability and repressed autophagy and apoptosis more in propofol-preconditioned HUVECs with HR injury than in HUVECs with HR injury only. A luciferase reporter assay confirmed the target reaction between miR-20b-5p and ULK1. Overexpression of ULK1 restrained the protective effect of miR-20b-5p in propofol-preconditioned HUVECs with HR injury. In conclusion, our results indicate that propofol inhibits autophagic cell death via the miR-20b-5p-ULKI axis and that ULK1 may be a therapeutic target for cardiovascular IR injury.


Assuntos
Autofagia/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Precondicionamento Isquêmico , MicroRNAs/metabolismo , Oxigênio/farmacologia , Propofol/farmacologia , Autofagia/fisiologia , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Hipnóticos e Sedativos/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Oxigênio/administração & dosagem
12.
J Biosci ; 452020.
Artigo em Inglês | MEDLINE | ID: mdl-32098916

RESUMO

This paper explores the potential mechanism of microRNA-143-5p regulation effects on pulmonary artery smooth muscle cells (PASMCs) functions in hypoxic pulmonary hypertension (HPH) via targeting HIF-1a, which may offer a new idea for HPH therapy. PASMCs were transfected with mimics control/miR-143-5p mimics or inhibitor control/miR-143-5p inhibitor. We used Western blotting and RT-qPCR to detect the protein and mRNA expressions, CCK-8 assay to detect cellular viability, Annexin V-FITC/PI staining and caspase- 3/cleaved caspase-3 protein to evaluate cellular apoptosis, transwell migration experiment for cellular migration measurement and Dual luciferase reporter gene assay to prove the target of miR-143-5p. Cells under hypoxic condition presented the decreased protein and mRNA expressions of α-smooth muscle actin (SM-α-actin), Myocardin, smooth muscle myosin heavy chain (SMMHC), and smooth muscle-22α (SM22α), Calponin1 and Hypoxia-inducible factor-1α(HIF-1α), the increased cell viability and miR-143-5p level; Overexpression of miR-143-5p obviously reduced vascular smooth muscle-specific contraction marker protein levels and cellular apoptosis, increased cellular migration of PASMCs with hypoxia stimulation; Low-expression of miR-143-5p caused the opposite changes, while co-transfected with Si HIF-1 α blocked the beneficial effects of miR-143-5p inhibition on PASMCs under hypoxia. MicroRNA-143-5p can promote the phenotype conversion, proliferation and migration of pulmonary artery smooth muscle cells under hypoxic condition through direct targeting of HIF-1α.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , MicroRNAs/metabolismo , Músculo Liso Vascular , Miócitos de Músculo Liso/fisiologia , Oxigênio/farmacologia , Artéria Pulmonar , Ensaios de Migração Celular , Células Cultivadas , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , MicroRNAs/genética
13.
J Biosci ; 452020.
Artigo em Inglês | MEDLINE | ID: mdl-32098921

RESUMO

Previous studies have demonstrated the cardioprotective role of resveratrol (Res). However, the underlying molecular mechanisms involved in the protective role of Res are still largely unknown. H9c2 cells were distributed into five groups: normal condition (Control), DMSO, 20 mMRes (dissolved with DMSO), hypoxia (Hyp), and Res+Hyp. Cell apoptosis was evaluated using flow cytometry and protein analysis of cleaved caspase 3 (cle-caspase 3). qRT-PCR assay was performed to measure the expression of microRNA-30d-5p (miR-30d-5p). MTT assay was performed to evaluate the cell proliferation. The relationship between miR-30d- 5p and silent information regulator 1 (SIRT1) was confirmed by luciferase reporter, RNA immunoprecipitation (RIP), and western blot assays. Western blot was performed to analyze NF-κB/p65 and I-κBα expressions. Our data showed that hypoxia enhanced apoptosis and NF-κB signaling pathway, which was alleviated by Res treatment. Hypoxia increased the expression of miR-30d-5p while decreased the SIRT1expression, which was also attenuated by Res treatment. Furthermore, miR-30d-5p depletion inhibited the proliferation, reduced apoptosis and decreased the expression of cle-caspase 3 in H9c2 cells with hypoxia treatment. Luciferase reporter, RIP, and western blot assays further confirmed that miR-30d-5p negatively regulated the expression of SIRT1. Interestingly, the rescue-of-function experiments further indicated that knockdown of SIRT1 attenuated the effect of miR-30d-5p depletion on proliferation, apoptosis NF-κB signaling pathway inH9c2 cells with hypoxia treatment. In addition, the suppression of NF-κB signaling pathway increased cell viability while decreased cell apoptosis in hypoxia-mediatedH9c2 cells. Our data suggested Res mayprotectH9c2 cells against hypoxia-induced apoptosis through miR-30d-5p/SIRT1/NF-κB axis.


Assuntos
Apoptose/efeitos dos fármacos , MicroRNAs/metabolismo , NF-kappa B/metabolismo , Oxigênio/administração & dosagem , Oxigênio/farmacologia , Resveratrol/farmacologia , Animais , Antioxidantes/farmacologia , Linhagem Celular , Regulação da Expressão Gênica/efeitos dos fármacos , MicroRNAs/genética , NF-kappa B/genética , Ratos , Sirtuína 1
14.
Health Secur ; 18(1): 36-48, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32078425

RESUMO

A fast, effective, and safe disinfection of personal protective equipment (PPE) is vitally important for emergency forces involved in biological hazards. This study aimed to investigate a broad range of disinfectants to improve the established disinfection procedure. We analyzed the efficacy of chlorine-, peracetic acid-, and oxygen-based disinfectants against Bacillus spores on PPE. Therefore, spores of different Bacillus species were exposed to disinfectants on PPE material by using a standardized procedure covering the dried spores with disinfectants and applying mechanical distribution. Efficacy of disinfectants was quantified by determining the reduction factor (log10 levels) and number of viable spores left afterward. The chlorine-based granulate Hypochlorit CA G (2% chlorine) sufficiently inactivated Bacillus spores of risk groups 1 and 2, even with temperatures ranging from -20 to 35°C. Wofasteril® SC super (1.75% peracetic acid) achieved a reliable reduction of risk groups 1 and 2 and even fully virulent Bacillus spores by ≥5 log10 levels on PPE. With this, Hypochlorit-CA G and Wofasteril® SC super proved to be promising alternatives to the previously proven and widely used peracetic acid compound Wofasteril® (2% peracetic acid) for the disinfection of PPE when bacterial spores are known to be the contaminating agent. These results will help to improve the disinfection of PPE during biological hazards by providing new data on promising alternative compounds.


Assuntos
Cloro/farmacologia , Desinfetantes/farmacologia , Ácido Peracético/farmacologia , Equipamento de Proteção Individual/microbiologia , Esporos Bacterianos/efeitos dos fármacos , Bacillus/isolamento & purificação , Controle de Infecções , Oxigênio/farmacologia , Temperatura
15.
J Toxicol Environ Health A ; 83(2): 82-94, 2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-32065759

RESUMO

Detoxifying effects of hyperoxia, which is widely used in clinical practice, were investigated using HaCat cells (human keratinocytes) treated with benzo[a]pyrene (B[a]P) as a model agent to induce adverse effects in the skin. It is well-established that B[a]P may produce toxicities including cancer, endocrine disruption, and phototoxicity involving DNA damage, free radical generation, and down regulation of nuclear factor erythroid 2-related factor 2 (Nrf2). It is well-known that Nrf2 is associated increase of antioxidant enzyme catalase (CAT) or detoxification enzyme glutathione S-transferase (GST) in HaCat cells treated with B[a]P under optimal condition of hyperoxia (40% oxygenation) conditions. To further examine the underlying basis of this phenomenon, factors affecting the expression of Nrf2 were determined. Nrf2 was upregulated accompanied by a rise in p38 MAPK, sequestosome-1 (also known as p62) and NF-κB. In contrast, Nrf2 was downregulated associated with an elevation in glycogen synthase kinase 3 beta (GSK-3ß) and peroxisome proliferator-activated receptor alpha (PPARα). Hyperoxia was also found to diminish DNA damage and generation of free radicals initiated in B[a]P-treated cells which was attributed to an significant rise of Nrf2, leading to elevated antioxidant activities or detoxification proteins including heme oxygenase 1 (HO-1), superoxide dismutase (SOD), glutathione peroxidase-1/2 (GPX-1/2), CAT, GST and glutathione (GSH). In addition, factors related to skin aging were also altered by hyperoxia. Data suggest that optimal hyperoxia exposure of 40% oxygenation may reduce cellular toxicity induced by B[a]P in HaCat cells as evidenced by inhibition of DNA damage, free radical generation, and down-regulation of Nrf2.


Assuntos
Benzo(a)pireno/toxicidade , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Oxigênio/farmacologia , Envelhecimento/fisiologia , Linhagem Celular , Sobrevivência Celular , Dano ao DNA , Radicais Livres , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Pele/metabolismo , Superóxido Dismutase
16.
Org Biomol Chem ; 18(11): 2076-2084, 2020 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-32108208

RESUMO

An Auxiliary Activity Family 5 (AA5) copper-radical alcohol oxidase (AlcOx) with promiscuous activity towards simple alkyl and aromatic alcohols was evaluated using real-time reaction progress monitoring. Reaction kinetics using variable time normalization analysis (VTNA) were determined from reaction progress curves. By this approach, a detailed view of the entire reaction time course under various conditions was obtained and used to identify parameters that will inform further process optimization development. Optimal activity was found impacted by several factors, including reaction pH, oxygen saturation, and the source of a co-oxidant, either HRP or a chemical alternative, potassium ferricyanide. Analysis of reaction progress curves demonstrated that reaction stalling occurred as a result of oxygen depletion and from a loss of enzyme activity over time. The cooperativity between AlcOx, horseradish peroxidase (HRP), and catalase that result in enhanced reactivity was explored, with reaction pH being identified as a key factor for optimal activity. The results show that a process with HRP is more robust than with potassium ferricyanide, but that both oxidants likely activate AlcOx by a similar mechanism. The phenomenon of product inhibition was investigated for representative reactants, revealing that reaction inhibition was more significant for butyraldehyde than for benzaldehyde. Our analysis suggests that this is linked to the greater proportion in which butyraldehyde exists in the hydrated form.


Assuntos
Oxirredutases do Álcool/metabolismo , Biocatálise , Aldeídos , Catalase/farmacologia , Cobre , Peroxidase do Rábano Silvestre/farmacologia , Cinética , Oxidantes/farmacologia , Oxigênio/metabolismo , Oxigênio/farmacologia
17.
Mol Biol Rep ; 47(3): 1613-1623, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31950326

RESUMO

Using stem and progenitor cells to treat retinal disorders holds great promise. Using defined culture conditions to maintain the desires phenotype is of utmost clinical importance. We cultured human retinal progenitor cells (hRPCs) in different conditions: such as normoxia (20% oxygen), and hypoxia (5% oxygen) with and without knock-out serum replacement (KOSR) to evaluate its effect on these cells. KOSR is known nutrient supplement often used to replace bovine serum for culturing embryonic or pluripotent stem cells, especially those destined for clinical applications. The purpose of this study was to identify the impact of different environmental and chemical cues to determine if this alters the fate of these cells. Our results indicate that cells cultured with or without KOSR do not show significant differences in viability, but that the oxygen tension can significantly change their viability (higher in hypoxia than normoxia). However, cells with KOSR in hypoxia condition expressed significantly higher stemness markers such as C-myc and Oct4 (31.20% and 13.44% respectively) in comparison to hRPCs cultured in KOSR at normoxia (12.07% and 4.05%). Furthermore, levels of markers for retinal commitment such as rhodopsin were significantly lower in the KOSR supplemented cells in hypoxia culture compared to normoxia. KOSR is known to improve proliferation and maintain stemness of embryonic cells and our experiments suggest that hRPCs maintain their proliferation and stemness characteristics in hypoxia with KOSR supplement. Normoxia, however, results in mature cell marker expression, suggesting a profound effect of oxygen tension on these cells.


Assuntos
Técnicas de Cultura de Células/métodos , Proliferação de Células/efeitos dos fármacos , Meios de Cultura Livres de Soro/farmacologia , Oxigênio/farmacologia , Retina/citologia , Células-Tronco/efeitos dos fármacos , Animais , Bovinos , Hipóxia Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Fator 3 de Transcrição de Octâmero/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Rodopsina/metabolismo , Soroalbumina Bovina/farmacologia , Células-Tronco/citologia , Células-Tronco/metabolismo
18.
Am J Physiol Regul Integr Comp Physiol ; 318(1): R49-R56, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31617751

RESUMO

Excessive erythrocytosis (EE) is the main sign of chronic mountain sickness (CMS), a maladaptive clinical syndrome prevalent in Andean and other high-altitude populations worldwide. The pathophysiological mechanism of EE is still controversial, as physiological variability of systemic respiratory, cardiovascular, and hormonal responses to chronic hypoxemia complicates the identification of underlying causes. Induced pluripotent stem cells derived from CMS highlanders showed increased expression of genes relevant to the regulation of erythropoiesis, angiogenesis, cardiovascular, and steroid-hormone function that appear to explain the exaggerated erythropoietic response. However, the cellular response to hypoxia in native CMS cells is yet unknown. This study had three related aims: to determine the hypoxic proliferation of native erythroid progenitor burst-forming unit-erythroid (BFU-E) cells derived from CMS and non-CMS peripheral blood mononuclear cells; to examine their sentrin-specific protease 1 (SENP1), GATA-binding factor 1 (GATA1), erythropoietin (EPO), and EPO receptor (EPOR) expression; and to investigate the functional upstream role of SENP1 in native progenitor differentiation into erythroid precursors. Native CMS BFU-E colonies showed increased proliferation under hypoxic conditions compared with non-CMS cells, together with an upregulated expression of SENP1, GATA1, EPOR; and no difference in EPO expression. Knock-down of the SENP1 gene abolished the augmented proliferative response. Thus, we demonstrate that native CMS progenitor cells produce a larger proportion of erythroid precursors under hypoxia and that SENP1 is essential for proliferation. Our findings suggest a significant intrinsic component for developing EE in CMS highlanders at the cellular and gene expression level that could be further enhanced by systemic factors such as alterations in respiratory control, or differential hormonal patterns.


Assuntos
Doença da Altitude/epidemiologia , Altitude , Células Precursoras Eritroides/metabolismo , Oxigênio/metabolismo , Oxigênio/farmacologia , Doença Crônica , Eritropoetina/sangue , Regulação da Expressão Gênica/efeitos dos fármacos , Predisposição Genética para Doença , Homeostase , Humanos , Hipóxia , Ferro/metabolismo , Leucócitos Mononucleares , Transcriptoma
19.
Chem Biol Interact ; 316: 108922, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31837296

RESUMO

Homeodomain interacting protein kinase-2 (HIPK2) has emerged as a crucial stress-responsive kinase that plays a critical role in regulating cell survival and apoptosis. However, whether HIPK2 participates in regulating cardiomyocyte survival during myocardial ischemia/reperfusion injury remains unclear. Here, we investigated the regulatory effect of HIPK2 on hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury and its potential underlying molecular mechanism. We found that HIPK2 expression was induced in response to H/R exposure. HIPK2 depletion by small interfering RNA (siRNA)-mediated gene silencing significantly decreased the viability and exacerbated H/R-induced apoptosis and reactive oxygen species (ROS) production in cardiomyocytes. Comparatively, HIPK2 overexpression effectively rescued H/R-impaired viability and repressed H/R-induced apoptosis and ROS production in cardiomyocytes. HIPK2 overexpression significantly increased the nuclear expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and enhanced Nrf2-mediated transcriptional activity. Moreover, HIPK2 overexpression significantly increased the transcription of Nrf2/ARE target genes. Additionally, Nrf2 inhibition partially reversed the HIPK2-mediated protective effect. Overall, these results demonstrate that HIPK2 overexpression protects cardiomyocytes from H/R-induced injury by enhancing Nrf2/ARE antioxidant signaling, data that suggest HIPK2 is a potential target for cardioprotection.


Assuntos
Apoptose/efeitos dos fármacos , Hipóxia Celular , Estresse Oxidativo/efeitos dos fármacos , Oxigênio/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Elementos de Resposta Antioxidante/genética , Células Cultivadas , Camundongos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Fator 2 Relacionado a NF-E2/antagonistas & inibidores , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/genética , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Espécies Reativas de Oxigênio/metabolismo
20.
J Orthop Res ; 38(2): 329-335, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31531986

RESUMO

The recommended treatment varies depending on the severity of muscle injuries. The aim of this study was to evaluate the in vitro myoblast proliferation and the in vivo histologic and physiologic effects of hyperbaric oxygen treatment on muscle healing after contusion. Cells from the C2C12 myoblast cell line were exposed to 100% O2 for 25 min then to air for 5 min at 2.5 atmospheres absolute in a hyperbaric chamber for a total treatment duration of 90 min per 48 h at intervals of 2, 4, 6 and 8 days. Cell growth measurements and western blot analysis of myogenin and actin were performed. Then, 18 mice aged 8-10 weeks were used in the muscle contusion model. The histologic and physiologic effects and muscle regeneration after hyperbaric oxygen treatment were evaluated. The myoblast growth rate was significantly higher (p < 0.05) after hyperbaric oxygen treatment. Densitometric evaluation demonstrated a 39% (p < 0.05) and 25% (p < 0.05) increase in myogenin and actin protein levels, respectively, in the cells treated with 1 dose of hyperbaric oxygen. Similarly, the myogenin and actin protein levels increased for samples receiving multiple hyperbaric oxygen treatments when compared with the control. Physiologic evaluation of fast twitch and tetanus strength revealed a significant difference between the control group and the 14-day hyperbaric oxygen group. In conclusion, hyperbaric oxygen treatment increases the myoblast growth rate and myogenin and actin production. Better histologic and physiologic performance were found after hyperbaric oxygen treatment in animal contusion model. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:329-335, 2020.


Assuntos
Contusões/terapia , Oxigenação Hiperbárica , Mioblastos/efeitos dos fármacos , Oxigênio/uso terapêutico , Actinas/metabolismo , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Contusões/patologia , Camundongos , Força Muscular/efeitos dos fármacos , Músculos/efeitos dos fármacos , Músculos/patologia , Miogenina/metabolismo , Oxigênio/farmacologia , Regeneração/efeitos dos fármacos
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