RESUMEN
Conventionally, the fabrication of liquid crystal lenticular microlens arrays (LCLMLAs) is complicated and costly. Here, we demonstrate a one-step fabrication technique for LCLMLAs, which is prepared through the photopolymerization-induced phase separation in the LC/polymer composite. The LCLMLAs possess both polarization-dependent and electrically tunable focusing properties. Furthermore, we construct a 14-view 2D/3D switchable autostereoscopic display prototype based on a 2D LCD panel and the prepared LCLMLA, which has a viewing angle of 14° and a crosstalk of 46.2% at the optimal viewing zone. The proposed LCLMLAs have the merits of simple fabrication, large-scale production, and low cost.
RESUMEN
Diffractive optical element is advantageous for miniaturization, arraying and integration of optical systems. They have been widely used in beam shaping, diffractive imaging, generating beam arrays, spectral optimization and other aspects. Currently, the vast majority of diffractive optics are not tunable. This limits the applicability and functionality of these devices. Here we report a tunable diffractive optical element controlled by light in the visible band. The diffractive optical element consists of a square gold microarray deposited on a deformable substrate. The substrate is made of a liquid crystal elastomer. When pumped by a 532â nm laser, the substrate is deformed to change the crystal lattice. This changes the far-field diffraction pattern of the device. The proposed concept establishes a light-controlled soft platform with great potential for tunable/reconfigurable photonic devices, such as filters, couplers, holograms and structural color displays.
RESUMEN
Considered a "Generally Recognized As Safe" (GRAS) bacterium, the plant growth-promoting rhizobacterium Paenibacillus has been widely applied in: agriculture, medicine, industry, and environmental remediation. Paenibacillus species not only accelerate plant growth and degrade toxic substances in wastewater and soil but also produce industrially-relevant enzymes and antimicrobial peptides. Due to a lack of genetic manipulation tools and methods, exploitation of the bioresources of naturally isolated Paenibacillus species has long been limited. Genetic manipulation tools and methods continue to improve in Paenibacillus, such as shuttle plasmids, promoters, and genetic tools of CRISPR. Furthermore, genetic transformation systems develop gradually, including: penicillin-mediated transformation, electroporation, and magnesium amino acid-mediated transformation. As genetic manipulation methods of homologous recombination and CRISPR-mediated editing system have developed gradually, Paenibacillus has come to be regarded as a promising microbial chassis for biomanufacturing, expanding its application scope, such as: industrial enzymes, bioremediation and bioadsorption, surfactants, and antibacterial agents. In this review, we describe the applications of Paenibacillus bioproducts, and then discuss recent advances and future challenges in the development of genetic manipulation systems in this genus. This work highlights the potential of Paenibacillus as a new microbial chassis for mining bioresources.
Asunto(s)
Paenibacillus , Paenibacillus/genética , Paenibacillus/metabolismo , Biodegradación AmbientalRESUMEN
Fibroblasts can be reprogrammed into cardiovascular progenitor cells (CPCs) using transgenic approaches, although the underlying mechanism remains unclear. We determined whether activation of endogenous genes such as Gata4, Nkx2.5, and Tbx5 can rapidly establish autoregulatory loops and initiate CPC generation in adult extracardiac fibroblasts using a CRISPR activation system. The induced fibroblasts (>80%) showed phenotypic changes as indicated by an Nkx2.5 cardiac enhancer reporter. The progenitor characteristics were confirmed by colony formation and expression of cardiovascular genes. Cardiac sphere induction segregated the early and late reprogrammed cells that can generate functional cardiomyocytes and vascular cells in vitro. Therefore, they were termed CRISPR-induced CPCs (ciCPCs). Transcriptomic analysis showed that cell cycle and heart development pathways were important to accelerate CPC formation during the early reprogramming stage. The CRISPR system opened the silenced chromatin locus, thereby allowing transcriptional factors to access their own promoters and eventually forming a positive feedback loop. The regenerative potential of ciCPCs was assessed after implantation in mouse myocardial infarction models. The engrafted ciCPCs differentiated into cardiovascular cells in vivo but also significantly improved contractile function and scar formation. In conclusion, multiplex gene activation was sufficient to drive CPC reprogramming, providing a new cell source for regenerative therapeutics.
Asunto(s)
Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Infarto del Miocardio , Animales , Diferenciación Celular/genética , Reprogramación Celular/genética , Fibroblastos/metabolismo , Ratones , Infarto del Miocardio/genética , Infarto del Miocardio/metabolismo , Infarto del Miocardio/terapia , Miocitos Cardíacos/metabolismo , Células Madre/metabolismoRESUMEN
N-n-Butyl haloperidol iodide (F2) is a novel compound that has antiproliferative and antifibrogenic activities. In this study we investigated the therapeutic potential of F2 against liver fibrosis in mice and the underlying mechanisms. Two widely used mouse models of fibrosis was established in mice by injection of either carbon tetrachloride (CCl4) or thioacetamide (TAA). The mice received F2 (0.75, 1.5 or 3 mg·kg-1·d-1, ip) for 4 weeks of fibrosis induction. We showed that F2 administration dose-dependently ameliorated CCl4- or TAA-induced liver fibrosis, evidenced by significant decreases in collagen deposition and c-Jun, TGF-ß receptor II (TGFBR2), α-smooth muscle actin (α-SMA), and collagen I expression in the liver. In transforming growth factor beta 1 (TGF-ß1)-stimulated LX-2 cells (a human hepatic stellate cell line) and primary mouse hepatic stellate cells, treatment with F2 (0.1, 1, 10 µM) concentration-dependently inhibited the expression of α-SMA, and collagen I. In LX-2 cells, F2 inhibited TGF-ß/Smad signaling through reducing the levels of TGFBR2; pretreatment with LY2109761 (TGF-ß signaling inhibitor) or SP600125 (c-Jun signaling inhibitor) markedly inhibited TGF-ß1-induced induction of α-SMA and collagen I. Knockdown of c-Jun decreased TGF-ß signaling genes, including TGFBR2 levels. We revealed that c-Jun was bound to the TGFBR2 promoter, whereas F2 suppressed the binding of c-Jun to the TGFBR2 promoter to restrain TGF-ß signaling and inhibit α-SMA and collagen I upregulation. In conclusion, the therapeutic benefit of F2 against liver fibrosis results from inhibition of c-Jun expression to reduce TGFBR2 and concomitant reduction of the responsiveness of hepatic stellate cells to TGF-ß1. F2 may thus be a potentially new effective pharmacotherapy for human liver fibrosis.
Asunto(s)
Haloperidol/análogos & derivados , Células Estrelladas Hepáticas/efectos de los fármacos , Cirrosis Hepática/tratamiento farmacológico , Animales , Tetracloruro de Carbono/administración & dosificación , Relación Dosis-Respuesta a Droga , Haloperidol/administración & dosificación , Haloperidol/farmacología , Células Estrelladas Hepáticas/metabolismo , Inyecciones Intraperitoneales , Cirrosis Hepática/inducido químicamente , Cirrosis Hepática/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Estructura Molecular , Relación Estructura-Actividad , Tioacetamida/administración & dosificación , Factor de Crecimiento Transformador beta1/antagonistas & inhibidores , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
Metasurface-based structural coloration is a promising enabling technology for advanced optical encryption with a high-security level. Herein, we propose a paradigm of electrically switchable, polarization-sensitive optical encryption based on designed metasurfaces integrated with polymer-dispersed liquid crystals. The metasurfaces consist of anisotropic and isotropic aluminum nanoaperture arrays. Optical images can be encrypted by elaborately arranging anisotropic and isotropic nanoapertures based on their polarization-dependent plasmonic resonance characteristics. We demonstrate high-quality encrypted images and QR codes with electrically switchable, polarization-sensitive properties based on PDLC-integrated aluminum nanoaperture arrays. The proposed technique can be applied to many fields including high-security optical encryption, security tags, anticounterfeiting, multichannel imaging, and dynamic displays.
RESUMEN
BACKGROUND: Colonoscopy adherence among populations at high risk for colorectal cancer (CRC) is crucial for the early diagnosis and treatment of CRC, but the adherence rate has been found to be poor. A short message service (SMS) is effective in promoting cancer screening, but its effectiveness in promoting colonoscopy among populations at high risk for CRC has not been well studied. METHODS: In this randomized controlled trial conducted in Guangzhou, China, participants who had tested positive during preliminary CRC screening (a high-risk factor questionnaire and/or an immunochemical fecal occult blood test) but had not undergone colonoscopy were randomized into low-frequency (monthly) intervention, high-frequency (biweekly) intervention, and control groups. The 2 intervention groups received behavioral theory-based SMS for 6 months. Data were obtained from the CRC screening database. The outcome was undergoing a colonoscopy examination. RESULTS: For the 1362 participants, the rates of colonoscopy adherence were 5.2%, 6.0%, and 10.5% at month 3 and 7.1%, 9.6%, and 13.7% at month 6 in the control, low-frequency intervention, and high-frequency intervention groups, respectively. After adjustments for potential confounders, the high-frequency intervention group was approximately twice as likely as the control group to undergo colonoscopy (adjusted hazard ratio, 1.99; 95% confidence interval, 1.32-3.01), whereas the difference between the low-frequency intervention and control groups was not statistically significant. The cost of SMS to increase colonoscopy uptake by 1 in the high-frequency intervention group was US $2.7. CONCLUSIONS: Text messages sent biweekly for 6 months to patients with positive preliminary screening results could increase colonoscopy adherence. SMS could be a prioritized intervention for promoting colonoscopy in large community-based populations.
Asunto(s)
Colonoscopía/estadística & datos numéricos , Neoplasias Colorrectales/diagnóstico , Detección Precoz del Cáncer/estadística & datos numéricos , Motivación , Cooperación del Paciente/estadística & datos numéricos , Envío de Mensajes de Texto , Estudios de Casos y Controles , China/epidemiología , Colonoscopía/psicología , Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/prevención & control , Análisis Costo-Beneficio , Detección Precoz del Cáncer/psicología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Factores de Riesgo , Encuestas y CuestionariosRESUMEN
Myofibroblast apoptosis is essential for normal resolution of wound repair, including cardiac infarction repair. Impaired cardiac myofibroblast (CMF) apoptosis is associated with excessive extracellular matrix (ECM) deposition, which could be responsible for pathological cardiac fibrosis. Conventionally, angiotensin II (Ang II), a soluble peptide, is implicated in fibrogenesis because it induces cardiac fibroblast (CFb) proliferation, differentiation, and collagen synthesis. However, the role of Ang II in regulation of CMF survival and apoptosis has not been fully clarified. In this report, we cultured neonatal rat CFbs, which transform into CMFs after passage 3 (6-8 days), and investigated the effects of Ang II on CMFs challenged by TNF-α combined with cycloheximide and the underlying mechanisms. Here, we show that Ang II rapidly activates MAPKs but not AKT in CMFs and confers apoptosis resistance, as evidenced by the inhibition of caspase-3 cleavage, early apoptotic cells and late apoptotic cells. This inhibitory effect of Ang II was reversed by blockade of AT1 or inactivation of ERK1/2 or RSK1 but not AT2, indicating that activation of the prosurvival AT1/ERK1/2/RSK1 signaling pathway mediates apoptosis resistance. TGF-ß, a latent fibrotic factor, was found to have no relation to Ang II-induced apoptosis resistance in our study. Furthermore, Ang II-mediated apoptosis resistance, which was conferred by activation of the AT1/ERK1/2/RSK1 signaling pathway, was also confirmed in human adult ventricular cardiac myofibroblasts. Collectively, our findings suggest a novel profibrotic mechanism of Ang II in which it promotes myofibroblast resistance to apoptosis in addition to classical mechanisms, providing a potential novel therapeutic approach by targeting prosurvival signaling pathways. © 2018 IUBMB Life, 71(1):261-276, 2019.
Asunto(s)
Angiotensina II/farmacología , Apoptosis/efectos de los fármacos , Proteína Quinasa 1 Activada por Mitógenos/genética , Proteína Quinasa 3 Activada por Mitógenos/genética , Miofibroblastos/efectos de los fármacos , Receptor de Angiotensina Tipo 1/genética , Proteínas Quinasas S6 Ribosómicas 90-kDa/genética , Bloqueadores del Receptor Tipo 2 de Angiotensina II/farmacología , Animales , Apoptosis/genética , Butadienos/farmacología , Supervivencia Celular/efectos de los fármacos , Cicloheximida/farmacología , Flavonoides/farmacología , Regulación de la Expresión Génica , Humanos , Imidazoles/farmacología , Losartán/farmacología , Proteína Quinasa 1 Activada por Mitógenos/antagonistas & inhibidores , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/antagonistas & inhibidores , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Miocardio/citología , Miocardio/metabolismo , Miofibroblastos/citología , Miofibroblastos/metabolismo , Nitrilos/farmacología , Cultivo Primario de Células , Inhibidores de Proteínas Quinasas/farmacología , Piridinas/farmacología , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Ratas , Ratas Sprague-Dawley , Receptor de Angiotensina Tipo 1/metabolismo , Proteínas Quinasas S6 Ribosómicas 90-kDa/antagonistas & inhibidores , Proteínas Quinasas S6 Ribosómicas 90-kDa/metabolismo , Transducción de Señal , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
Although resident cardiac stem cells have been reported, regeneration of functional cardiomyocytes (CMs) remains a challenge. The present study identifies an alternative progenitor source for CM regeneration without the need for genetic manipulation or invasive heart biopsy procedures. Unlike limb skeletal muscles, masseter muscles (MM) in the mouse head are developed from Nkx2-5 mesodermal progenitors. Adult masseter muscle satellite cells (MMSCs) display heterogeneity in developmental origin and cell phenotypes. The heterogeneous MMSCs that can be characterized by cell sorting based on stem cell antigen-1 (Sca1) show different lineage potential. While cardiogenic potential is preserved in Sca1+ MMSCs as shown by expression of cardiac progenitor genes (including Nkx2-5), skeletal myogenic capacity is maintained in Sca1- MMSCs with Pax7 expression. Sca1+ MMSC-derived beating cells express cardiac genes and exhibit CM-like morphology. Electrophysiological properties of MMSC-derived CMs are demonstrated by calcium transients and action potentials. These findings show that MMSCs could serve as a novel cell source for cardiomyocyte replacement.
Asunto(s)
Diferenciación Celular , Músculo Masetero/citología , Desarrollo de Músculos/genética , Miocitos Cardíacos/citología , Células Satélite del Músculo Esquelético/citología , Potenciales de Acción/fisiología , Animales , Ataxina-1/genética , Ataxina-1/metabolismo , Biomarcadores/metabolismo , Calcio/metabolismo , Linaje de la Célula/genética , Expresión Génica , Genes Reporteros , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Proteína Homeótica Nkx-2.5/genética , Proteína Homeótica Nkx-2.5/metabolismo , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , Músculo Masetero/metabolismo , Ratones , Ratones Transgénicos , Miocitos Cardíacos/metabolismo , Factor de Transcripción PAX7/genética , Factor de Transcripción PAX7/metabolismo , Fenotipo , Regeneración , Células Satélite del Músculo Esquelético/metabolismo , Proteína Fluorescente RojaRESUMEN
Ischemia/reperfusion injury is associated with contractile dysfunction and increased cardiomyocyte death. Overexpression of the hematopoietic lineage substrate-1-associated protein X-1 (HAX-1) has been shown to protect from cellular injury but the function of endogenous HAX-1 remains obscure due to early lethality of the knockout mouse. Herein we generated a cardiac-specific and inducible HAX-1 deficient model, which uncovered an unexpected role of HAX-1 in regulation of sarco/endoplasmic reticulum Ca-ATPase (SERCA2a) in ischemia/reperfusion injury. Although ablation of HAX-1 in the adult heart elicited no morphological alterations under non-stress conditions, it diminished contractile recovery and increased infarct size upon ischemia/reperfusion injury. These detrimental effects were associated with increased loss of SERCA2a. Enhanced SERCA2a degradation was not due to alterations in calpain and calpastatin levels or calpain activity. Conversely, HAX-1 overexpression improved contractile recovery and maintained SERCA2a levels. The regulatory effects of HAX-1 on SERCA2a degradation were observed at multiple levels, including intact hearts, isolated cardiomyocytes and sarcoplasmic reticulum microsomes. Mechanistically, HAX-1 ablation elicited increased production of reactive oxygen species at the sarco/endoplasic reticulum compartment, resulting in SERCA2a oxidation and a predisposition to its proteolysis. This effect may be mediated by NAPDH oxidase 4 (NOX4), a novel binding partner of HAX-1. Accordingly, NOX inhibition with apocynin abrogated the effects of HAX-1 ablation in hearts subjected to ischemia/reperfusion injury. Taken together, our findings reveal a role of HAX-1 in the regulation of oxidative stress and SERCA2a degradation, implicating its importance in calcium homeostasis and cell survival pathways.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas/metabolismo , Proteolisis , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Anciano , Animales , Calpaína/metabolismo , Retículo Endoplásmico/metabolismo , Femenino , Eliminación de Gen , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/patología , Insuficiencia Cardíaca/fisiopatología , Humanos , Péptidos y Proteínas de Señalización Intracelular , Masculino , Ratones Endogámicos C57BL , Persona de Mediana Edad , Contracción Miocárdica , Daño por Reperfusión Miocárdica/patología , Daño por Reperfusión Miocárdica/fisiopatología , Miocardio/patología , Miocitos Cardíacos/metabolismo , NADPH Oxidasa 4/metabolismo , Oxidación-Reducción , Estrés Oxidativo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Recuperación de la Función , Retículo Sarcoplasmático/metabolismoRESUMEN
Heat shock protein 20 (Hsp20) has been shown to be a critical regulator of cardiomyocyte survival upon cardiac stress. In this study, we investigated the functional significance of a novel human Hsp20 mutation (S10F) in peripartum cardiomyopathy. Previous findings showed that cardiac-specific overexpression of this mutant were associated with reduced autophagy, left ventricular dysfunction and early death in male mice. However, this study indicates that females have normal function with no alterations in autophagy but died within a week after 1-4 pregnancies. Further examination of mutant females revealed left ventricular chamber dilation and hypertrophic remodelling. Echocardiography demonstrated increases in left ventricular end-systolic volume and left ventricular end-diastolic volume, while ejection fraction and fractional shortening were depressed following pregnancy. Subsequent studies revealed that cardiomyocyte apoptosis was elevated in mutant female hearts after the third delivery, associated with decreases in the levels of Bcl-2/Bax and Akt phosphorylation. These results indicate that the human S10F mutant is associated with dysregulation of cell survival signalling, accelerated heart failure and early death post-partum.
RESUMEN
Therapeutic angiogenesis has emerged as a promising strategy to regenerate the damaged blood vessels resulting from ischemic diseases such as myocardial infarction (MI). However, the functional integration of implanted endothelial cells (ECs) in infarcted heart remains challenging. We herein develop an EC generation approach by inhibiting microRNA-495 (miR-495) in human induced pluripotent stem cells (hiPSCs) and assess the angiogenic potential for MI treatment. The anti-angiogenic miR-495 belonging to Dlk1-Dio3 miR cluster was identified through expression profiling and computational analysis. Loss-of-function experiments for miR-495 were performed using a lentiviral transfer of antisense sequence in hiPSCs. The pluripotency of hiPSCs was not impacted by the genetic modification. Induced with differentiation medium, miR-495 inhibition enhanced the expression of EC genes of hiPSCs, as well as the yield of ECs. Newly derived ECs displayed prominent angiogenic characteristics including tube formation, cell migration, and proliferation. Mechanistically, miR-495 mediated the expression of endothelial or angiogenic genes by directly targeting vascular endothelial zinc finger 1. After transplantation in immunodeficient MI mice, the derived ECs significantly increased neovascularization in the infarcted heart, prevented functional worsening, and attenuated expansion of infarct size. The functional integration of the implanted ECs into coronary networks was also enhanced by inhibiting miR-495. miR-495 represents a new target not only for promoting EC generation from hiPSCs but also for enhancing angiogenesis and engraftment of hiPSC-derived ECs in ischemic heart. Stem Cells 2017;35:337-350.
Asunto(s)
Células Madre Pluripotentes Inducidas/metabolismo , MicroARNs/antagonistas & inhibidores , Neovascularización Fisiológica , Animales , Secuencia de Bases , Cardiotónicos/metabolismo , Diferenciación Celular/genética , Vasos Coronarios/patología , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Células Endoteliales/citología , Células Endoteliales/metabolismo , Humanos , Ratones , MicroARNs/genética , MicroARNs/metabolismo , Familia de Multigenes , Infarto del Miocardio/genética , Infarto del Miocardio/patología , Infarto del Miocardio/terapia , Trasplante de Células Madre , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
The major underpinning of massive cell death associated with myocardial infarction involves opening of the mitochondrial permeability transition pore (mPTP), resulting in disruption of mitochondria membrane integrity and programmed necrosis. Studies in human lymphocytes suggested that the hematopoietic-substrate-1 associated protein X-1 (HAX-1) is linked to regulation of mitochondrial membrane function, but its role in controlling mPTP activity remains obscure. Herein we used models with altered HAX-1 expression levels in the heart and uncovered an unexpected role of HAX-1 in regulation of mPTP and cardiomyocyte survival. Cardiac-specific HAX-1 overexpression was associated with resistance against loss of mitochondrial membrane potential, induced by oxidative stress, whereas HAX-1 heterozygous deficiency exacerbated vulnerability. The protective effects of HAX-1 were attributed to specific down-regulation of cyclophilin-D levels leading to reduction in mPTP activation. Accordingly, cyclophilin-D and mPTP were increased in heterozygous hearts, but genetic ablation of cyclophilin-D in these hearts significantly alleviated their susceptibility to ischemia/reperfusion injury. Mechanistically, alterations in cyclophilin-D levels by HAX-1 were contributed by the ubiquitin-proteosomal degradation pathway. HAX-1 overexpression enhanced cyclophilin-D ubiquitination, whereas proteosomal inhibition restored cyclophilin-D levels. The regulatory effects of HAX-1 were mediated through interference of cyclophilin-D binding to heat shock protein-90 (Hsp90) in mitochondria, rendering it susceptible to degradation. Accordingly, enhanced Hsp90 expression in HAX-1 overexpressing cardiomyocytes increased cyclophilin-D levels, as well as mPTP activation upon oxidative stress. Taken together, our findings reveal the role of HAX-1 in regulating cyclophilin-D levels via an Hsp90-dependent mechanism, resulting in protection against activation of mPTP and subsequent cell death responses.
Asunto(s)
Ciclofilinas/metabolismo , Proteínas de Transporte de Membrana Mitocondrial/metabolismo , Miocardio/metabolismo , Proteínas/metabolismo , Adenoviridae/metabolismo , Animales , Calcio/metabolismo , Muerte Celular , Peptidil-Prolil Isomerasa F , Proteínas HSP90 de Choque Térmico/metabolismo , Heterocigoto , Humanos , Técnicas In Vitro , Péptidos y Proteínas de Señalización Intracelular , Masculino , Ratones , Membranas Mitocondriales/metabolismo , Poro de Transición de la Permeabilidad Mitocondrial , Miocitos Cardíacos/metabolismo , Estrés Oxidativo , Unión Proteica , Transporte de Proteínas , Proteolisis , Ratas Sprague-Dawley , UbiquitinaciónRESUMEN
It has been reported that CXCR4-overexpressing mesenchymal stem cells (MSCCX4 ) can repair heart tissue post myocardial infarction. This study aims to investigate the MSCCX4-derived paracrine cardio-protective signaling in the presence of myocardial infarction. Mesenchymal stem cells (MSCs) were divided into 3 groups: MSC only, MSCCX4 , and CXCR4 gene-specific siRNA-transduced MSC. Mesenchymal stem cells were exposed to hypoxia, and then MSCs-conditioned culture medium was incubated with neonatal and adult cardiomyocytes, respectively. Cell proliferation-regulating genes were assessed by real-time polymerase chain reaction (RT-PCR). In vitro: The number of cardiomyocytes undergoing DNA synthesis, cytokinesis, and mitosis was increased to a greater extent in MSCCX4 medium-treated group than control group, while this proproliferative effect was reduced in CXCR4 gene-specific siRNA-transduced MSC-treated cells. Accordingly, the maximal enhancement of vascular endothelial growth factor, cyclin 2, and transforming growth factor-ß2 was observed in hypoxia-exposed MSCCX4 . In vivo: MSCs were labeled with enhanced green fluorescent protein (EGFP) and engrafted into injured myocardium in rats. The number of EGFP and CD31 positive cells in the MSCCX4 group was significantly increased than other 2 groups, associated with the reduced left ventricular (LV) fibrosis, the increased LV free wall thickness, the enhanced angiogenesis, and the improved contractile function. CXCR4 overexpression can mobilize MSCs into ischemic area, whereby these cells can promoted angiogenesis and alleviate LV remodeling via paracrine signaling mechanism.
Asunto(s)
Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/metabolismo , Infarto del Miocardio/terapia , Miocitos Cardíacos/metabolismo , Comunicación Paracrina/genética , Receptores CXCR4/genética , Animales , Animales Recién Nacidos , Hipoxia de la Célula , Medios de Cultivo Condicionados/farmacología , Ciclina A2/genética , Ciclina A2/metabolismo , Regulación de la Expresión Génica , Genes Reporteros , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Masculino , Células Madre Mesenquimatosas/citología , Infarto del Miocardio/genética , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Miocitos Cardíacos/patología , Neovascularización Fisiológica , Cultivo Primario de Células , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Ratas , Ratas Sprague-Dawley , Receptores CXCR4/antagonistas & inhibidores , Receptores CXCR4/metabolismo , Transfección , Factor de Crecimiento Transformador beta2/genética , Factor de Crecimiento Transformador beta2/metabolismo , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , Remodelación VentricularRESUMEN
The chemokine (C-X-C motif) receptor 4 (CXCR4) is expressed on native cardiomyocytes and can modulate isolated cardiomyocyte contractility. This study examines the role of CXCR4 in cardiomyocyte response to ischaemia-reperfusion (I/R) injury. Isolated adult rat ventricular cardiomyocytes were subjected to hypoxia/reoxygenation (H/R) to simulate I/R injury. In response to H/R injury, the decrease in CXCR4 expression was associated with dysfunctional energy metabolism indicated by an increased adenosine diphosphate/adenosine triphosphate (ADP/ATP) ratio. CXCR4-overexpressing cardiomyocytes were used to determine whether such overexpression (OE) can prevent bio-energetic disruption-associated cell death. CXCR4 OE was performed with adenoviral infection with CXCR4 encoding-gene or non-translated nucleotide sequence (Control). The increased CXCR4 expression was observed in cardiomyocytes post CXCR4-adenovirus transduction and this OE significantly reduced the cardiomyocyte contractility under basal conditions. Although the same extent of H/R-provoked cytosolic calcium overload was measured, the hydrogen peroxide-induced decay of mitochondrial membrane potential was suppressed in CXCR4 OE group compared with control group, and the mitochondrial swelling was significantly attenuated in CXCR4 group, implicating that CXCR4 OE prevents permeability transition pore opening exposure to overload calcium. Interestingly, this CXCR4-induced mitochondrial protective effect is associated with the enhanced signal transducer and activator of transcription 3 (expression in mitochondria. Consequently, in the presence of H/R, mitochondrial dysfunction was mitigated and cardiomyocyte death was decreased to 65% in the CXCR4 OE group as compared with the control group. I/R injury leads to the reduction in CXCR4 in cardiomyocytes associated with the dysfunctional energy metabolism, and CXCR4 OE can alleviate mitochondrial dysfunction to improve cardiomyocyte survival.
Asunto(s)
Mitocondrias Cardíacas/metabolismo , Daño por Reperfusión Miocárdica/metabolismo , Miocitos Cardíacos/metabolismo , Receptores CXCR4/metabolismo , Adenoviridae/metabolismo , Animales , Calcio/farmacología , Cardiotónicos/farmacología , Muerte Celular/efectos de los fármacos , Hipoxia de la Célula/efectos de los fármacos , Citosol/efectos de los fármacos , Citosol/metabolismo , Mitocondrias Cardíacas/efectos de los fármacos , Mitocondrias Cardíacas/patología , Daño por Reperfusión Miocárdica/patología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Estrés Oxidativo/efectos de los fármacos , Ratas Sprague-Dawley , Factor de Transcripción STAT3/metabolismoRESUMEN
Stem cell-based therapy is a promising intervention for ischemic heart diseases. However, the functional integrity of stem cells is impaired in an ischemic environment. Here, we report a novel finding that heat shock significantly improves Sca-1(+) stem cell survival in an ischemic environment by the regulation of the triangle: heat shock factor 1 (HSF1), HSF1/miR-34a, and heat shock protein 70 (HSP70). Initially we prove that HSP70 is the key chaperone-mediating cytoprotective effect of heat shock in Sca-1(+) cells and then we establish miR-34a as a direct repressor of HSP70. We found that miR-34a was downregulated in heat shocked Sca-11 stem cells (HSSca-11 cells) [corrected]. Intriguingly, we demonstrate that the downregulation of miR-34a is attributed to HSF1-mediated epigenetic repression through histone H3 Lys27 trimethylation (H3K27me3) on miR-34a promoter. Moreover, we show that heat shock induces exosomal transfer of HSF1 from Sca-1(+) cells, which directs ischemic cardiomyocytes toward a prosurvival phenotype by epigenetic repression of miR-34a. In addition, our in vivo study demonstrates that transplantation of (HS) Sca-1(+) cells significantly reduces apoptosis, attenuates fibrosis, and improves global heart functions in ischemic myocardium. Hence, our study provides not only novel insights into the effects of heat shock on stem cell survival and paracrine behavior but also may have therapeutic values for stem cell therapy in ischemic heart diseases.
Asunto(s)
Antígenos Ly/genética , Proteínas de Unión al ADN/genética , Proteínas de la Membrana/genética , MicroARNs/genética , Células Madre/metabolismo , Factores de Transcripción/genética , Antígenos Ly/metabolismo , Apoptosis/genética , Supervivencia Celular/genética , Proteínas de Unión al ADN/metabolismo , Exosomas/genética , Proteínas HSP70 de Choque Térmico , Factores de Transcripción del Choque Térmico , Respuesta al Choque Térmico/genética , Humanos , Proteínas de la Membrana/metabolismo , Miocitos Cardíacos/metabolismo , Células Madre/citología , Factores de Transcripción/metabolismoRESUMEN
RATIONALE: Ischemic heart disease is characterized by contractile dysfunction and increased cardiomyocyte death, induced by necrosis and apoptosis. Increased cell survival after an ischemic insult is critical and depends on several cellular pathways, which have not been fully elucidated. OBJECTIVE: To test the hypothesis that the anti-apoptotic hematopoietic lineage substrate-1-associated protein X-1 (HAX-1), recently identified as regulator of cardiac Ca cycling, also may ameliorate cellular injury with an ischemic insult. METHODS AND RESULTS: We report that cardiac ischemia/reperfusion injury is associated with significant decreases in HAX-1 levels ex vivo and in vivo. Accordingly, overexpression of HAX-1 improved contractile recovery, coupled with reduced infarct size, plasma troponin I level, and apoptosis. The beneficial effects were associated with decreased endoplasmic reticulum (ER) stress response through specific inhibition of the inositol-requiring enzyme (IRE-1) signaling pathway, including its downstream effectors caspase-12 and the transcription factor C/EBP homologous protein. Conversely, HAX-1 heterozygous-deficient hearts exhibited increases in infarct size and IRE-1 activity. The inhibitory effects of HAX-1 were mediated by its binding to the N-terminal fragment of the heat shock protein 90 (Hsp90). Moreover, HAX-1 sequestered Hsp90 from IRE-1 to the phospholamban-sarcoplasmic/endoplasmic reticulum calcium ATPase complex. The HAX-1 regulation was further supported by loss of IRE-1 inhibition in presence of the Hsp90 inhibitor, 17-N-allylamino-17-demethoxygeldanamycin. CONCLUSIONS: Cardiac ischemia-reperfusion injury is associated with decreases in HAX-1 levels. Consequently, overexpression of HAX-1 promotes cardiomyocyte survival, mediated by its interaction with Hsp90 and specific inhibition of IRE-1 signaling at the ER/sarcoplasmic reticulum.
Asunto(s)
Proteínas HSP90 de Choque Térmico/metabolismo , Infarto del Miocardio/prevención & control , Daño por Reperfusión Miocárdica/prevención & control , Miocitos Cardíacos/metabolismo , Proteínas/metabolismo , Animales , Apoptosis , Benzoquinonas/farmacología , Biomarcadores/sangre , Calcio/metabolismo , Proteínas de Unión al Calcio/metabolismo , Células Cultivadas , Modelos Animales de Enfermedad , Estrés del Retículo Endoplásmico , Regulación de la Expresión Génica , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Péptidos y Proteínas de Señalización Intracelular , Lactamas Macrocíclicas/farmacología , Masculino , Proteínas de la Membrana/metabolismo , Ratones , Ratones Noqueados , Ratones Transgénicos , Contracción Miocárdica , Infarto del Miocardio/genética , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Infarto del Miocardio/fisiopatología , Daño por Reperfusión Miocárdica/genética , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/patología , Daño por Reperfusión Miocárdica/fisiopatología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Unión Proteica , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas/genética , Ratas , Ratas Sprague-Dawley , Recuperación de la Función , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/metabolismo , Transducción de Señal , Factores de Tiempo , Transducción Genética , Transfección , Troponina I/sangreRESUMEN
OBJECTIVES: To investigate a survey about acceptance of central slaughtering of live poultry in residents of Guangzhou. METHODS: We conducted a telephone survey by sampling residents with fixed-line telephone and with normal hearing, whose age is more than 15 years, by Mitofsky-Waksberg two-stage method during Jan 6(th) to 8(th), 2014. 358 residents finished the telephone questionnaire by 12 320 health hot line. We investigated the acceptance rate of city-wide central slaughtering permanently. We compared the difference between the respondents and the 2010 Guangzhou census data by Cohen's effect sizes (w) and weighted by population age and sex. We used χ(2) test to compare the acceptance rate of central slaughtering in residents with different characteristic. We used multiple logistic regression analysis to analyze the factors. RESULTS: The difference in gender and age was small between respondents and the 2010 Guangzhou census data (w value was 0.13, 0.28, respectively), but that in education and marital status was large (w value was 0.52, 0.31, respectively). 49.0% (95% CI: 43.7%-54.3%) accept city-wide central slaughtering permanently. The acceptance rate of city-wide central slaughtering permanently in those who bought fresh, chilled and frozen poultry in their family in previous year was 54.3% (133/245), 60.0% (57/95) and 59.8% (49/82), respectively. It was more than those who didn't buy fresh, chilled and frozen poultry (38.1% (43/113), 44.9% (118/263) and 45.7% (126/276); χ(2) values were 8.15, 6.40 and 5.03; P values were 0.004, 0.011 and 0.025, respectively). The acceptance rate of city-wide central slaughtering permanently in those who deem fresh poultry taste better than live poultry was 64.9% (24/38). It more than those who deem not (47.0%, 151/320) (χ(2) = 4.22, 6.02, P = 0.040, 0.014, respectively). The acceptance rate of city-wide central slaughtering permanently in the male (OR = 2.68, 95% CI: 1.64-4.37) and those who deem getting sick due to buying live birds from LPM (OR = 1.72, 95% CI: 1.05-2.82), who can accept only fresh poultry carcass supply (OR = 2.39, 95% CI: 1.33-4.30), Who bought live poultry in their family in previous year (OR = 0.29, 95% CI: 0.11-0.74), who will decrease the consumption after ban on live poultry sale (OR = 0.50, 95% CI: 0.30-0.83) was 58.6% (109/186), 59.0% (92/156), 60.7% (139/230), 44.9% (132/295), 36.6% (68/186), respectively. CONCLUSION: In the early stage of avian influenza A(H7N9) epidemic in Guangzhou, the rate of acceptance of central slaughtering permanently in residents was not so high. Who deem getting sick due to buying live birds from LPM, who could accept only fresh poultry carcass supply and the male more accept city-wide central slaughtering permanently.
Asunto(s)
Actitud Frente a la Salud , Industria para Empaquetado de Carne , Aves de Corral , Animales , Aves , Epidemias , Humanos , Subtipo H7N9 del Virus de la Influenza A , Gripe Aviar , Gripe Humana , Masculino , Encuestas y CuestionariosRESUMEN
Exosomes, nano-vesicles naturally released from living cells, have been well recognized to play critical roles in mediating cell-to-cell communication. Given that diabetic hearts exhibit insufficient angiogenesis, it is significant to test whether diabetic cardiomyocyte-derived exosomes possess any capacity in regulating angiogenesis. In this study, we first observed that both proliferation and migration of mouse cardiac endothelial cells (MCECs) were inhibited when co-cultured with cardiomyocytes isolated from adult Goto-Kakizaki (GK) rats, a commonly used animal model of type 2 diabetes. However, GK-myocyte-mediated anti-angiogenic effects were negated upon addition of GW4869, an inhibitor of exosome formation/release, into the co-cultures. Next, exosomes were purified from the myocyte culture supernatants by differential centrifugation. While exosomes derived from GK myocytes (GK-exosomes) displayed similar size and molecular markers (CD63 and CD81) to those originated from the control Wistar rat myocytes (WT-exosomes), their regulatory role in angiogenesis is opposite. We observed that the MCEC proliferation, migration and tube-like formation were inhibited by GK-exosomes, but were promoted by WT-exosomes. Mechanistically, we found that GK-exosomes encapsulated higher levels of miR-320 and lower levels of miR-126 compared to WT-exosomes. Furthermore, GK-exosomes were effectively taken up by MCECs and delivered miR-320. In addition, transportation of miR-320 from myocytes to MCECs could be blocked by GW4869. Importantly, the exosomal miR-320 functionally down-regulated its target genes (IGF-1, Hsp20 and Ets2) in recipient MCECs, and overexpression of miR-320 inhibited MCEC migration and tube formation. GK exosome-mediated inhibitory effects on angiogenesis were removed by knockdown of miR-320. Together, these data indicate that cardiomyocytes exert an anti-angiogenic function in type 2 diabetic rats through exosomal transfer of miR-320 into endothelial cells. Thus, our study provides a novel mechanism underlying diabetes mellitus-induced myocardial vascular deficiency which may be caused by secretion of anti-angiogenic exosomes from cardiomyocyes.
Asunto(s)
Diabetes Mellitus Experimental/genética , Células Endoteliales/metabolismo , Exosomas/metabolismo , MicroARNs/genética , Miocitos Cardíacos/metabolismo , Compuestos de Anilina/farmacología , Animales , Compuestos de Bencilideno/farmacología , Transporte Biológico , Biomarcadores/metabolismo , Movimiento Celular , Proliferación Celular , Técnicas de Cocultivo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patología , Células Endoteliales/efectos de los fármacos , Células Endoteliales/patología , Exosomas/efectos de los fármacos , Exosomas/patología , Regulación de la Expresión Génica , Proteínas del Choque Térmico HSP20/genética , Proteínas del Choque Térmico HSP20/metabolismo , Humanos , Factor I del Crecimiento Similar a la Insulina/genética , Factor I del Crecimiento Similar a la Insulina/metabolismo , MicroARNs/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Neovascularización Fisiológica , Proteína Proto-Oncogénica c-ets-2/genética , Proteína Proto-Oncogénica c-ets-2/metabolismo , Ratas , Ratas Wistar , Transducción de SeñalRESUMEN
BACKGROUND: Live poultry traders (LPTs) have greater risk to avian influenza due to occupational exposure to poultry. This study investigated knowledge, attitudes and practices of LPTs relating to influenza A (H7N9). METHODS: Using multi-stage cluster sampling, 306 LPTs were interviewed in Guangzhou by a standardized questionnaire between mid-May to June, 2013. Hierarchical logistic regression models were used to identify factors associated with preventive practices and attitudes towards various control measures implemented in live poultry markets against H7N9. RESULTS: Only 46.1% of the respondents recognized risks associated with contacts with bird secretions or droppings, and only 22.9% perceived personally "likely/very likely" to contract H7N9 infection. Around 60% of the respondents complied with hand-washing and wearing gloves, and only 20% reported wearing face masks. Only 16.3% of the respondents agreed on introducing central slaughtering of poultry. Being younger, involving in slaughtering poultry, having longer working hours, less access to H7N9-related information and poorer knowledge, and perceiving lower personal susceptibility to H7N9 infection were negatively associated with preventive practices. Comparing with previous studies conducted when human cases of H5N1 avian influenza infection was first identified in Guangdong, LPTs' perceived susceptibility to novel influenza viruses increased significantly but acceptance for central slaughtering of poultry remained low. CONCLUSIONS: Information on avian influenza provided through multiple communication tools may be necessary to promote knowledge among poultry traders. Familiarity with risk may have led to the lower perceived vulnerability to avian influenza and less protective actions among the LPTs particularly for those involving more risky exposure to live poultry. Reasons for the consistently low acceptance for central slaughtering of poultry await further exploration.