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1.
Animals (Basel) ; 13(21)2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-37958103

RESUMO

Quantifying emission factors of ammonia and particulate matter (PM) in livestock production systems is crucial for assessing and mitigating the environmental impact of animal production and for ensuring industry sustainability. This study aimed to determine emission factors of ammonia, total suspended particles (TSPs), PM10, and PM2.5 for piglets and growing-finishing pigs at a commercial pig farm in Korea. It also sought to identify factors influencing these emission factors. The research found that the emission factors measured were generally lower than those currently used in Korea, but were consistent with findings from individual research studies in the literature. Seasonal variations were observed, with ammonia emissions peaking in spring and autumn, and PM emissions rising in summer. Correlation analyses indicated that the number of animals and their average age correlated positively with both ammonia and PM emission factors. Ventilation rate was also positively correlated with PM emissions. Future extended field measurements across diverse pig farms will offer deeper insights into the emission factors of pig farms in Korea, guiding the development of sustainable livestock management practices.

2.
J Microbiol ; 61(10): 881-889, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37668956

RESUMO

Prions are infectious proteins that mostly replicate in self-propagating amyloid conformations (filamentous protein polymers) and consist of structurally altered normal soluble proteins. Prions can arise spontaneously in the cell without any clear reason and are generally considered fatal disease-causing agents that are only present in mammals. However, after the seminal discovery of two prions, [PSI+] and [URE3], in the eukaryotic model microorganism Saccharomyces cerevisiae, at least ten more prions have been discovered, and their biological and pathological effects on the host, molecular structure, and the relationship between prions and cellular components have been studied. In a filamentous fungus model, Podospora anserina, a vegetative incomparability-related [Het-s] prion that directly triggers cell death during anastomosis (hyphal fusion) was discovered. These prions in eukaryotic microbes have extended our understanding to overcome most fatal human prion/amyloid diseases. A prokaryotic microorganism (Clostridium botulinum) was reported to have a prion analog. The transcriptional regulators of C. botulinum-Rho can be converted into the self-replicating prion form ([RHO-X-C+]), which may affect global transcription. Here, we outline the major issues with prions in microbes and the lessons learned from the relatively uncovered microbial prion world.


Assuntos
Príons , Proteínas de Saccharomyces cerevisiae , Animais , Humanos , Príons/química , Príons/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Amiloide/química , Amiloide/metabolismo , Proteínas Amiloidogênicas/metabolismo , Proteínas Fúngicas/metabolismo , Mamíferos/metabolismo
3.
Animals (Basel) ; 13(15)2023 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-37570260

RESUMO

Accurate ventilation control is crucial for maintaining a healthy and productive environment in research-specialized pig facilities. This study aimed to evaluate actual ventilation rates and ventilation efficiency by investigating different inlet and exhaust configurations. The research was conducted in two pig rooms, namely pig room A and pig room B, in the absence of animals and workers to focus solely on evaluating the ventilation system's performance. Actual ventilation rates were measured using hood-type anemometers, and the local air change per hour was analyzed at various measurement points via tracer gas decay experiments. The results demonstrated that specific inlet and exhaust combinations, such as side inlet/chimney outlet and ceiling inlet/side outlet, exhibited higher ventilation rates. However, the measured ventilation rates were much lower than the manufacturer's specifications. The side exhaust fan closer to the pig activity space demonstrated better ventilation effectiveness for the animals than the chimney exhaust fan. Additionally, the ceiling inlet exhibited superior air distribution and uniformity. Lower ventilation rates and higher infiltration ratios resulted in reduced ventilation efficiency, with the difference between pig and worker activity spaces being pronounced. This study emphasizes the importance of selecting optimal inlet and exhaust configurations to achieve efficient ventilation and create a healthy environment for both pigs and workers.

4.
Sci Rep ; 12(1): 20706, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36456670

RESUMO

In this paper, we present a new fractional epidemiological model on a heterogeneous network to investigate Middle East respiratory syndrome (MERS-CoV), which is caused by a virus in the coronavirus family. We also consider the development of equations for the camel population, given that it is the primary animal source of the virus, as well as direct human interaction with this population. The model is configured in an SIS form for both the human population and the camel population. We study the equilibrium positions of the system and the conditions for the existence of each of them, as well as the local stability of each equilibrium position. Then, we provide some numerical examples that compare real data and numerical results.


Assuntos
Infecções por Coronavirus , Coronavírus da Síndrome Respiratória do Oriente Médio , Animais , Humanos , Camelus , Infecções por Coronavirus/epidemiologia , Modelos Epidemiológicos
5.
Emerg Infect Dis ; 28(12): 2513-2515, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36223653

RESUMO

A global monkeypox outbreak began in May 2022. Limited data exist on specimen type performance in associated molecular diagnostics. Consequently, a diverse range of specimen sources were collected in the initial weeks of the outbreak in Ontario, Canada. Our clinical evaluation identified skin lesions as the optimal diagnostic specimen source.


Assuntos
Mpox , Humanos , Mpox/diagnóstico , Mpox/epidemiologia , Monkeypox virus/genética , Ontário/epidemiologia
6.
ACS Nano ; 16(10): 15827-15836, 2022 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-36069332

RESUMO

Smart contact lenses have the potential to serve as noninvasive healthcare devices or virtual displays. However, their implementation is limited by the lack of suitable power sources for microelectronic devices. This Article demonstrates smart contact lenses with fully embedded glucose fuel cells that are safe, flexible, and durable against deformations. These fuel cells produced stable power throughout the day or during intermittent use after storage for weeks. When the lenses were exposed to 0.05 mM glucose solution, a steady-state maximum power density of 4.4 µW/cm2 was achieved by optimizing the chemistry and porous structure of the fuel cell components. Additionally, even after bending the lenses in half 100 times, the fuel cell performance was maintained without any mechanical failure. Lastly, when the fuel cells were connected to electroresponsive hydrogel capacitors, we could clearly distinguish between the tear glucose levels under normal and diabetic conditions through the naked eye.

7.
Front Psychol ; 12: 709926, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34646199

RESUMO

While player characters (PCs) are the key element in engaging players in narrative games, the experience and relationship of the player with the PC have received scarce attention from the perspective of the subjective player experience. The diversity of players and the importance of the PC in the game suggests meaningful connections between how players relate to their PC and the resulting satisfaction with the game. We, therefore, investigated in this study how the player-character relationship influences satisfaction of the player with the game. We performed semi-structured in-depth interviews with 12 players of The Last of Us Part II, a game that has elicited highly polarized reactions in relation to how players responded to a switch of the PC in the game. Through thematic analysis, three themes were found, illustrating the connection between aspects of the player-character relationship and the overall game satisfaction. The themes are "Tolerance of forced character switch", "Malleability of character image" and "Flexibility of character attachment". We discuss how those findings should be taken into consideration when designing diverse and meaningful gaming experiences.

8.
JMIR Serious Games ; 9(2): e24449, 2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-34014175

RESUMO

BACKGROUND: The number of older adult gamers who play mobile games is growing worldwide. Earlier studies have reported that digital games provide cognitive, physical, and socioemotional benefits for older adults. However, current mobile games that understand older adults' gameplay experience and reflect their needs are very scarce. Furthermore, studies that have analyzed older adults' game experience in a holistic manner are rare. OBJECTIVE: The purpose of this study was to suggest mobile game design guidelines for adults older than 50 years from a holistic gaming experience perspective. Adopting a human-centric approach, this study analyzes middle-aged and older adults' gameplay experience and suggests practical design guides to increase accessibility and satisfaction. METHODS: We organized a living laboratory project called the "Intergenerational Play Workshop." In this workshop, 40 middle-aged and older adults (mean age 66.75 years, age range 50-85 years) played commercial mobile games of various genres with young adult partners for 1 month (8 sessions). Using a convergent parallel mixed-method design, we conducted a qualitative analysis of dialogue, game diaries, and behavioral observations during the workshop and a quantitative analysis of the satisfaction level of the game elements for the mobile games that they played. RESULTS: This project was active from April 2019 to December 2021, and the data were collected at the workshops from July 1 to August 28, 2019. Based on the identified themes of positive and negative experiences from the qualitative data, we proposed 45 design guides under 3 categories: (1) cognitive and physical elements, (2) psychological and socioemotional elements, and (3) consumption contextual elements. Our empirical research could reaffirm the proposals from previous studies and provide new guidelines for improving the game design. In addition, we demonstrate how existing commercial games can be evaluated quantitatively by using the satisfaction level of each game's elements and overall satisfaction level. CONCLUSIONS: The final guidelines were presented to game designers to easily find related information and enhance the overall understanding of the game experience of middle-aged and older adults.

10.
J Nanosci Nanotechnol ; 18(3): 2144-2147, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29448732

RESUMO

The hot deformation behavior of hot-extruded AA7175 was investigated with flow curves and processing maps through hot torsion tests. The flow curves and the deformed microstructures revealed that dynamic recrystallization (DRX) occurred in the hot-extruded AA7175 during hot working. The failure strain was highest at medium temperature. This was mainly influenced by the dynamic precipitation of fine rod-shaped MgZn2. The processing map determined the optimal deformation condition for the alloy during hot working.

11.
Mol Cell Biochem ; 439(1-2): 105-115, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28795305

RESUMO

During the past decade, microRNAs have continuously been suggested as a promising therapeutic tool due to their beneficial effects, such as their multi-targets and multi-functions in pathologic conditions. As a pathologic phenotype is generally regulated by multiple signaling pathways, in this study we identified a microRNA regulating multiple target genes within cardiac hypertrophic signaling pathways. microRNA-133a is known to play a crucial role in cardiac hypertrophy. However, the role of microRNA-133a, which may regulate several signaling pathways in norepinephrine-induced cardiac hypertrophy via multi-targeting, has not been investigated. In the current study, we showed that microRNA-133a can protect cardiomyocyte hypertrophy against norepinephrine stimulation in neonatal rat ventricular cardiomyocytes via new targets, PKCδ and Gq, all of which are related to downstream signaling pathways of the α1-adrenergic receptor. Taken together, these results suggest the advantages of the therapeutic use of microRNAs as an effective potential drug regulating multiple signaling pathways under pathologic conditions.


Assuntos
Cardiomegalia/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , MicroRNAs/metabolismo , Miócitos Cardíacos/metabolismo , Proteína Quinase C-delta/metabolismo , Transdução de Sinais , Animais , Cardiomegalia/patologia , Miócitos Cardíacos/patologia , Ratos , Receptor A1 de Adenosina/metabolismo
12.
Oncotarget ; 8(55): 93360-93372, 2017 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-29212155

RESUMO

Pathologic proliferation and migration of vascular smooth muscle cells (VSMCs) exacerbate cardiovascular disease. MicroRNAs (miRNAs), as endogenous inhibitors of protein synthesis, are expected to modulate pathologic proliferation of VSMCs. Here we report that both platelet-derived growth factor receptor (PDGFR) targeting miR-9 and a small molecule that increases miR-9 can inhibit the serum-induced proliferation of VSMCs. First, based on miRNA-target prediction databases and empirical data, we have selected miR-9 as a potent anti-proliferative miRNA in VSMCs. Further examination indicated that miR-9 directly targets PDGFR disrupting downstream signaling cascades, and this resulted in inhibition of VSMC proliferation and migration. Exogenous delivery of miR-9 inhibited VSMC proliferation in vitro, and a small molecule that increased miR-9 expression also inhibited neointima formation following balloon injury in vivo. We provide evidence of miRNA-mediated modulation of VSMC proliferation and further demonstrate that small molecule-mediated regulation of miRNA targeting a key regulator of VSMC proliferation is a viable therapeutic strategy for treating vascular disease involving pathologic VSMC proliferation such as restenosis.

13.
J Vasc Res ; 54(2): 100-108, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28407626

RESUMO

Adult stem cells have been studied as a promising therapeutic modality for the functional restoration of the damaged heart. In the present study, a strategy for enhancing the angiogenic efficacy of human mesenchymal stem cells (hMSCs) using micro-RNA was examined. We investigated whether micro-RNA-146a (miR-146a) influences the secretion of vascular endothelial growth factor (VEGF) and angiogenesis of MSCs. Our data indicated that miR-146a-transfected hMSCs (hMSCmiR-146a) decreased the expression of neurofibromin 2, an inhibitor of p21-activated kinase-1 (PAK1). miR-146a also increased the expression of Ras-related C3 botulinum toxin substrate 1 and PAK1, which are known to induce VEGF expression, and the formation of vascular branches was increased in hMSCmiR-146a compared to hMSCs treated with VEGF. VEGF and p-Akt were increased in hMSCmiR-146a. Furthermore, injection of hMSCmiR-146a after ischemia/reperfusion (I/R) injury led to a reduction of fibrosis area and increased VEGF expression, confirming the regenerative capacity such as reparative angiogenesis in the infarcted area. Cardiac functions in I/R injury were improved following injection of hMSCmiR-146a compared to the I/R group. Taken together, these data suggest that miR-146 is a novel microRNA that regulates VEGF expression, and its use may be an effective strategy for enhancing the therapeutic efficacy of hMSC transplantation into the I/R-injured heart.


Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/metabolismo , Infarto do Miocárdio/cirurgia , Traumatismo por Reperfusão Miocárdica/cirurgia , Miocárdio/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Regiões 3' não Traduzidas , Animais , Sítios de Ligação , Células Cultivadas , Modelos Animais de Doenças , Fibrose , Humanos , Masculino , MicroRNAs/genética , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/patologia , Neovascularização Fisiológica , Neurofibromina 2/genética , Neurofibromina 2/metabolismo , Ratos Sprague-Dawley , Recuperação de Função Fisiológica , Regeneração , Transdução de Sinais , Transfecção , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/genética , Quinases Ativadas por p21/metabolismo , Proteínas rac de Ligação ao GTP/metabolismo
14.
Sci Transl Med ; 8(344): 344ra86, 2016 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-27334261

RESUMO

Heart failure remains a major public health concern with a 5-year mortality rate higher than that of most cancers. Myocardial disease in heart failure is frequently accompanied by impairment of the specialized electrical conduction system and myocardium. We introduce an epicardial mesh made of electrically conductive and mechanically elastic material, to resemble the innate cardiac tissue and confer cardiac conduction system function, to enable electromechanical cardioplasty. Our epicardium-like substrate mechanically integrated with the heart and acted as a structural element of cardiac chambers. The epicardial device was designed with elastic properties nearly identical to the epicardial tissue itself and was able to detect electrical signals reliably on the moving rat heart without impeding diastolic function 8 weeks after induced myocardial infarction. Synchronized electrical stimulation over the ventricles by the epicardial mesh with the high conductivity of 11,210 S/cm shortened total ventricular activation time, reduced inherent wall stress, and improved several measures of systolic function including increases of 51% in fractional shortening, ~90% in radial strain, and 42% in contractility. The epicardial mesh was also capable of delivering an electrical shock to terminate a ventricular tachyarrhythmia in rodents. Electromechanical cardioplasty using an epicardial mesh is a new pathway toward reconstruction of the cardiac tissue and its specialized functions.


Assuntos
Sistema de Condução Cardíaco/cirurgia , Telas Cirúrgicas , Animais , Cardiomiopatias/fisiopatologia , Cardiomiopatias/cirurgia , Condutividade Elétrica , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/cirurgia , Frequência Cardíaca/fisiologia , Ventrículos do Coração/fisiopatologia , Ventrículos do Coração/cirurgia , Masculino , Contração Miocárdica/fisiologia , Infarto do Miocárdio/fisiopatologia , Infarto do Miocárdio/cirurgia , Ratos Sprague-Dawley
15.
Sci Rep ; 6: 23472, 2016 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-27008992

RESUMO

Genetic ablation of BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3), an essential regulator of cardiac cell death, is an effective way to prevent cardiac cell death triggered by pathologic conditions. However, currently there exists no known means, such as inhibitors, to down-regulate BNIP3 in mature heart. Here, we report that a small molecule inducer of microRNA-182 (miR-182) suppressed ischemia/reperfusion (I/R)-induced cardiac cell death by down-regulating BNIP3. We first selected miR-182 as a potent BNIP3-targeting miRNA based on miRNA-target prediction databases and empirical data. The subsequent screening of small molecules for inducing miR-182 expression identified Kenpaullone as a hit compound. Both exogenous miR-182 and Kenpaullone significantly suppressed hypoxia-induced cardiomyocyte death in vitro. To investigate the effect of changing substituents of Kenpaullone on miR-182 expression, we synthesized 9 derivatives of Kenpaullone. Among these derivatives, compound 5 showed significantly improved ability to induce miR-182 expression. The results of the in vivo study showed that compound 5 significantly improved heart function following I/R-injury in rats. Our study provides strong evidence that the small molecule-mediated up-regulation of miRNAs is a viable strategy to down-regulate target proteins with no known chemical inhibitor and that compound 5 may have potential to prevent I/R-inflicted cardiac cell death.


Assuntos
Proteínas de Membrana/genética , MicroRNAs/genética , Proteínas Mitocondriais/genética , Isquemia Miocárdica/fisiopatologia , Miócitos Cardíacos/citologia , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Benzazepinas/química , Benzazepinas/farmacologia , Morte Celular/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Testes de Função Cardíaca/efeitos dos fármacos , Indóis/química , Indóis/farmacologia , Masculino , Isquemia Miocárdica/genética , Miócitos Cardíacos/efeitos dos fármacos , Ratos , Bibliotecas de Moléculas Pequenas/síntese química , Regulação para Cima
16.
Stem Cell Res Ther ; 6: 174, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26373837

RESUMO

INTRODUCTION: Despite the success of interventional processes such as drug-eluting stents, complete prevention of restenosis is still hindered by impaired or delayed endothelialization or both. Here, we report that 1H-pyrrole-2,5-dione-based small molecule-generated mesenchymal stem cell-derived functional endothelial cells (MDFECs) facilitated rapid transmural coverage of injured blood vessels. METHODS: Small molecules that induced CD31 expression were screened by principal component analysis (PCA). Rat mesenchymal stem cells (MSCs) were treated with selected small molecules for up to 16 days, and the expression levels of CD90 and CD31 were examined by immunocytochemistry. In vitro functional assays of MDFECs, including tube formation assays and nitric oxide production assays, were performed. After MDFECs (intravenous, 3×10(6) cells per animal) were injected into balloon-injured rats, neointima formation was monitored for up to 21 days. The endothelial coverage of denuded blood vessels was evaluated by Evans Blue staining. The functionality of repaired blood vessels was evaluated by measuring vasorelaxation and hemodynamic changes. Additionally, derivatives of the selected small molecules were examined for their ability to induce endothelial markers. RESULTS: PCA indicated that 3-(2,4-dichlorophenyl)-4-(1-methyl-1H-indol-3-yl)-1H-pyrrole-2,5-dione effectively induced MDFECs. MDFECs inhibited the neointima formation of denuded blood vessels by facilitating more rapid endothelialization. Further examination indicated that derivatives with a 1H-pyrrole-2,5-dione moiety are important for initiating the endothelial cell differentiation of MSCs. CONCLUSIONS: Small molecules with 1H-pyrrole-2,5-dione as a core structure have great potential to improve the efficacy of MSC-based cell therapy for vascular diseases, such as atherosclerosis and restenosis.


Assuntos
Células Endoteliais/efeitos dos fármacos , Indóis/farmacologia , Maleimidas/farmacologia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/efeitos dos fármacos , Lesões do Sistema Vascular/terapia , Cicatrização , Animais , Diferenciação Celular , Células Cultivadas , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Endotélio Vascular/citologia , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Molécula-1 de Adesão Celular Endotelial a Plaquetas/genética , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Ratos , Ratos Sprague-Dawley , Antígenos Thy-1/genética , Antígenos Thy-1/metabolismo
17.
Biochem Biophys Res Commun ; 465(3): 349-55, 2015 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-26253469

RESUMO

Under distinct pathological heart conditions, the expression of a single miRNA can display completely opposite patterns. However, the mechanism underlying the bidirectional regulation of a single miRNA and the clinical implications of this regulation remain largely unknown. To address this issue, we examined the regulation of miR-1, one of the most abundant miRNAs in the heart, during cardiac hypertrophy and ischemia/reperfusion (I/R). Our data indicated that different magnitudes and chronicities of ROS levels in cardiomyocytes resulted in differential expression of miR-1, subsequently altering the expression of myocardin. In animal models, the administration of a miR-1 mimic attenuated cardiac hypertrophy by suppressing the transverse aortic constriction-induced increase in myocardin expression, whereas the administration of anti-miR-1 ameliorated I/R-induced cardiac apoptosis and deterioration of heart function. Our findings indicated that a pathologic stimulus such as ROS can bidirectionally alter the expression of miRNA to contribute to the development of pathological conditions exhibiting distinct phenotypes and that the meticulous adjustment of the pathological miRNA levels is required to improve clinical outcomes.


Assuntos
Cardiomegalia/metabolismo , Insuficiência Cardíaca/metabolismo , MicroRNAs/metabolismo , Miocárdio/metabolismo , Proteínas Nucleares/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transativadores/metabolismo , Animais , Apoptose , Cardiomegalia/genética , Células Cultivadas , Regulação da Expressão Gênica/genética , Insuficiência Cardíaca/genética , MicroRNAs/genética , Proteínas Nucleares/genética , Ratos , Ratos Sprague-Dawley , Transativadores/genética
18.
Biochem Biophys Res Commun ; 465(2): 299-304, 2015 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-26265044

RESUMO

Heart diseases such as myocardial infarction (MI) can damage individual cardiomyocytes, leading to the activation of cell death programs. The most scrutinized type of cell death in the heart is apoptosis, and one of the key events during the propagation of apoptotic signaling is the formation of apoptosomes, which relay apoptotic signals by activating caspase-9. As one of the major components of apoptosomes, apoptotic protease activating factor 1 (Apaf-1) facilitates the formation of apoptosomes containing cytochrome c (Cyto-c) and deoxyadenosine triphosphate (dATP). Thus, it may be possible to suppress the activation of the apoptotic program by down-regulating the expression of Apaf-1 using miRNAs. To validate this hypothesis, we selected a number of candidate miRNAs that were expected to target Apaf-1 based on miRNA target prediction databases. Among these candidate miRNAs, we empirically identified miR-17 as a novel Apaf-1-targeting miRNA. The delivery of exogenous miR-17 suppressed Apaf-1 expression and consequently attenuated formation of the apoptosome complex containing caspase-9, as demonstrated by co-immunoprecipitation and immunocytochemistry. Furthermore, miR-17 suppressed the cleavage of procaspase-9 and the subsequent activation of caspase-3, which is downstream of activated caspase-9. Cell viability tests also indicated that miR-17 pretreatment significantly prevented the norepinephrine-induced apoptosis of cardiomyocytes, suggesting that down-regulation of apoptosome formation may be an effective strategy to prevent cellular apoptosis. These results demonstrate the potential of miR-17 as an effective anti-apoptotic agent.


Assuntos
Apoptose/genética , Apoptossomas/metabolismo , Fator Apoptótico 1 Ativador de Proteases/metabolismo , MicroRNAs/metabolismo , Miócitos Cardíacos/metabolismo , Animais , Animais Recém-Nascidos , Apoptose/efeitos dos fármacos , Apoptossomas/efeitos dos fármacos , Apoptossomas/genética , Fator Apoptótico 1 Ativador de Proteases/genética , Caspase 3/genética , Caspase 3/metabolismo , Caspase 9/genética , Caspase 9/metabolismo , Citocromos c/genética , Citocromos c/metabolismo , Nucleotídeos de Desoxiadenina/metabolismo , Regulação da Expressão Gênica , MicroRNAs/genética , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Norepinefrina/farmacologia , Cultura Primária de Células , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Transfecção
19.
Biol Res ; 48: 45, 2015 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-26283227

RESUMO

BACKGROUND: Low survival rate of transplanted cells compromises the efficacy of cell therapy. Hexokinase II (HKII) is known to have anti-apoptotic activity through its interaction with mitochondria. The objective was to identify miRNAs targeting HKII and investigate whether miRNA-mediated modulation of HKII could improve the survival of mesenchymal stem cells (MSCs) exposed to H2O2. The expression of HKII in MSCs exposed to H2O2 was evaluated, and HKII-targeting miRNA was screened based on miRNA-target prediction databases. The effect of H2O2 on the expression of the selected HKII-targeting miRNA was examined and the effect of modulation of the selected HKII-targeting miRNA using anti-miRNA on H2O2-induced apoptosis of MSC was evaluated. RESULTS: H2O2 (600 µM) induced cell death of MSCs and decreased mitochondrial HKII expression. We have identified miR-181a as a HKII-targeting miRNA and H2O2 increased the expression of miR-181a in MSCs. Delivery of anti-miR-181a, which neutralizes endogenous miR-181a, significantly attenuated H2O2-induced decrease of HKII expression and disruption of mitochondrial membrane potential, improving the survival of MSCs exposed to H2O2. CONCLUSIONS: These findings suggest that H2O2-induced up-regulation of miR-181a contributes to the cell death of MSCs by down-regulating HKII. Neutralizing miR-181a can be an effective way to prime MSCs for transplantation into ischemic tissues.


Assuntos
Apoptose , Glioma/patologia , Hexoquinase/metabolismo , Peróxido de Hidrogênio/toxicidade , Células-Tronco Mesenquimais/patologia , MicroRNAs/metabolismo , Diferenciação Celular , Movimento Celular , Sobrevivência Celular , Glioma/metabolismo , Humanos , Peróxido de Hidrogênio/administração & dosagem , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/enzimologia , MicroRNAs/antagonistas & inibidores , Mitocôndrias/enzimologia , Invasividade Neoplásica , Espécies Reativas de Oxigênio , Reação em Cadeia da Polimerase em Tempo Real , Semaforinas/genética , Semaforinas/metabolismo
20.
Stem Cell Res Ther ; 6: 147, 2015 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-26296645

RESUMO

INTRODUCTION: Mesenchymal stem cells (MSCs) have therapeutic potential for the repair of myocardial injury. The efficacy of MSC therapy for myocardial regeneration mainly depends on the survival of cells after transplantation into the infarcted heart. In the transplanted regions, reactive oxygen species (ROS) can cause cell death, and this process depends on caspase activation and autophagosome formation. METHODS: A Software TargetScan was utilized to search for microRNAs (miRNAs) that target caspase-3 mRNA. Six candidate miRNAs including let-7b were selected and transfected into human MSCs in vitro. Expression of MEK-EKR signal pathways and autophagy-related genes were detected. Using ischemia/reperfusion model (I/R), the effect of MSCs enriched with let-7b was determined after transplantation into infarcted heart area. Miller catheter was used to evaluate cardiac function. RESULTS: Here, we report that let-7b targets caspase-3 to regulate apoptosis and autophagy in MSCs exposed to ROS. Let-7b-transfected MSCs (let-7b-MSCs) showed high expression of survival-related proteins, including p-MEK, p-ERK and Bcl-2, leading to a decrease in Annexin V/PI- and TUNEL-positive cells under ROS-rich conditions. Moreover, autophagy-related genes, including Atg5, Atg7, Atg12 and beclin-1, were significantly downregulated in let-7b-MSCs. Using a rat model of acute myocardial infarction, we found that intramyocardial injection of let-7b-MSCs markedly enhanced left ventricular (LV) function and microvessel density, in accordance with a reduced infarct size and the expression of caspase-3. CONCLUSIONS: Taken together, these data indicate that let-7b may protect MSCs implanted into infarcted myocardium from apoptosis and autophagy by directly targeting caspase-3 signaling.


Assuntos
Caspase 3/metabolismo , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/terapia , Animais , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Autofagia/genética , Western Blotting , Caspase 3/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Células Cultivadas , Humanos , Peróxido de Hidrogênio/farmacologia , Marcação In Situ das Extremidades Cortadas , Células-Tronco Mesenquimais/efeitos dos fármacos , MicroRNAs , Traumatismo por Reperfusão Miocárdica/enzimologia , Ratos , Reação em Cadeia da Polimerase em Tempo Real
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