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Smoking is recognized as the major cause of lung cancer. Healthcare professionals play an important role in lung cancer prevention policies, as they act as a source of guidance for patients and advocates. The following survey evaluated prevalence, knowledge, and attitudes toward tobacco smoking among a sample of workers in "IRCCS Istituto Tumori "Giovanni Paolo II" of Bari, an Italian cancer hospital. An anonymous questionnaire was completed by 104 healthcare professionals to collect personal and occupational data about smoking status, knowledge about the harms of smoking, current legislation in place, Second-Hand Smoke (SHS) awareness, and, for ex-smokers, the reasons for quitting. Among participants, 17.8% were current smokers, 26.2% former smokers, and 56% never smoked. Only 40% acknowledged that the smoking ban is generally respected, and 63.2% reported that they smoke during working hours. Most of the participants perceived tobacco control policy as an efficient way to protect public health. Currently, the implementation of Italian anti-smoking legislation has so far improved neither smoking cessation rates nor the will to quit smoking completely. Our experience highlights that to date the anti-smoking strategies have limited efficacy even in a cancer center; in fact, there is still a large prevalence of smokers among hospital personnel. Therefore, it is strongly suggested that interventions be shared with all healthcare workers, specifically aimed at developing a culture of health promotion.
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Neoplasias , Nicotiana , Conhecimentos, Atitudes e Prática em Saúde , Pessoal de Saúde , Humanos , Itália/epidemiologia , Neoplasias/epidemiologia , Neoplasias/prevenção & controle , Percepção , Prevalência , Inquéritos e QuestionáriosRESUMO
To efficiently lower virus infectivity and combat virus epidemics or pandemics, it is important to discover broadly acting antivirals. Here, we investigated two naturally occurring polyphenols, Epigallocatechin gallate (EGCG) and Resveratrol (RES), and polyphenol-functionalized nanoparticles for their antiviral efficacy. Concentrations in the low micromolar range permanently inhibited the infectivity of high doses of enteroviruses (107 PFU/mL). Sucrose gradient separation of radiolabeled viruses, dynamic light scattering, transmission electron microscopic imaging and an in-house developed real-time fluorescence assay revealed that polyphenols prevented infection mainly through clustering of the virions into very stable assemblies. Clustering and stabilization were not compromised even in dilute virus solutions or after diluting the polyphenols-clustered virions by 50-fold. In addition, the polyphenols lowered virus binding on cells. In silico docking experiments of these molecules against 2- and 3-fold symmetry axes of the capsid, using an algorithm developed for this study, discovered five binding sites for polyphenols, out of which three were novel binding sites. Our results altogether suggest that polyphenols exert their antiviral effect through binding to multiple sites on the virion surface, leading to aggregation of the virions and preventing RNA release and reducing cell surface binding.
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Stem cells expressing c-kit have been identified in the adult epicardium. In mice, after myocardial infarction, these cells proliferate, migrate to the injury site and differentiate toward myocardial and vascular phenotype. We hypothesized that, acutely after myocardial infarction, pericardial sac integrity and pericardial fluid (PF) may play a role on epicardial cell gene expression, proliferation and differentiation. Microarray analysis indicated that, in the presence of an intact pericardial sac, myocardial infarction modulated 246 genes in epicardial cells most of which were related to cell proliferation, cytoskeletal organization, wound repair and signal transduction. Interestingly, WT1, Tbx18 and RALDH2, notably involved in epicardial embryonic development, were markedly up-regulated. Importantly, coexpression of stem cell antigen c-kit and WT1 and/or Tbx18 was detected by immunohistochemistry in the mouse epicardium during embryogenesis as well as in adult mouse infarcted heart. Injection of human pericardial fluid from patients with acute myocardial ischemia (PFMI) in the pericardial cavity of non-infarcted mouse hearts, enhanced, epicardial cell proliferation and WT1 expression. Further, PFMI supplementation to hypoxic cultured human epicardial c-kit(+) cells increased WT1 and Tbx18 mRNA expression. Finally, insulin-like growth factor 1, hepatocyte growth factor and high mobility group box 1 protein, previously involved in cardiac c-kit(+) cell proliferation and differentiation, were increased in PFMI compared to the pericardial fluid of non ischemic patients. In conclusion, myocardial infarction reactivates an embryonic program in epicardial c-kit(+) cells; soluble factors released in the pericardial fluids following myocardial necrosis may play a role in this process.
Assuntos
Infarto do Miocárdio/metabolismo , Pericárdio/metabolismo , Proteínas Proto-Oncogênicas c-kit/metabolismo , Idoso , Animais , Diferenciação Celular , Proliferação de Células , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Infarto do Miocárdio/patologia , Derrame Pericárdico/metabolismo , Proteínas Proto-Oncogênicas c-kit/genética , Transdução de Sinais , Proteínas WT1/metabolismoRESUMO
Lipid nanovesicles (NVs) are the first nanoformulation that entered the clinical use in oncology for the treatment of solid tumors. They are indeed versatile systems which can be loaded with either hydrophobic or hydrophilic molecules, for both imaging and drug delivery, and with high biocompatibility, and limited immunogenicity. In the present work, NVs with a lipid composition resembling that of natural vesicles were prepared using the ultrasonication method. The NVs were successfully loaded with fluorophores molecules (DOP-F-DS and a fluorescent protein), inorganic nanoparticles (quantum dots and magnetic nanoparticles), and anti-cancer drugs (SN-38 and doxorubicin). The encapsulation of such different molecules showed the versatility of the developed systems. The size of the vesicles varied from 100 up to 300 nm depending on the type of loaded species, which were accommodated either into the lipid bilayer or into the aqueous core according to their hydrophobic or hydrophilic nature. Viability assays were performed on cellular models of breast cancer (MCF-7 and MDA-MB-231). Results showed that NVs with encapsulated both drugs simultaneously led to a significant reduction of the cellular activity (up to 22%) compared to the free drugs or to the NVs encapsulated with only one drug. Lipidomic analysis suggested that the mechanism of action of the drugs is the same, whether they are free or encapsulated, but administration of the drugs by means of nanovesicles is more efficient in inducing cellular damage, likely because of a quicker internalization and a sustained release. This study confirms the versatility and the potential of lipid NVs for cancer treatment, as well as the validity of the ultrasound preparation method for their preparation.
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Dengue virus (DENV) causes 390 million infections per year. Infections can be asymptomatic or range from mild fever to severe haemorrhagic fever and shock syndrome. Currently, no effective antivirals or safe universal vaccine is available. In the present work we tested different gold nanoparticles (AuNP) coated with ligands ω-terminated with sugars bearing multiple sulfonate groups. We aimed to identify compounds with antiviral properties due to irreversible (virucidal) rather than reversible (virustatic) inhibition. The ligands varied in length, in number of sulfonated groups as well as their spatial orientation induced by the sugar head groups. We identified two candidates, a glucose- and a lactose-based ligand showing a low EC50 (effective concentration that inhibit 50% of the viral activity) for DENV-2 inhibition, moderate toxicity and a virucidal effect in hepatocytes with titre reduction of Median Tissue Culture Infectious Dose log10TCID50 2.5 and 3.1. Molecular docking simulations complemented the experimental findings suggesting a molecular rationale behind the binding between sulfonated head groups and DENV-2 envelope protein.
Assuntos
Antivirais/química , Antivirais/farmacologia , Vírus da Dengue/efeitos dos fármacos , Dengue/tratamento farmacológico , Ouro/química , Nanopartículas Metálicas/química , Animais , Linhagem Celular , Linhagem Celular Tumoral , Chlorocebus aethiops , Células Hep G2 , Hepatócitos/virologia , Humanos , Ligantes , Simulação de Acoplamento Molecular , Células VeroRESUMO
This article investigates the effects of tobacco control policies on smoking initiation, cessation and prevalence by examining the papers published in the last 5 years. Twenty-one articles have been selected by two authors and sorted by four types of tobacco control: tobacco prices, anti-smoking campaigns for young people, mass media intervention and public smoking bans. Price/tax increase has deterrent effect on smoking initiation but does not promote smoking cessation; intervention on young people could reduce the smoking initiation if carried out at an early age and if acted on social skills and with peer-led approach, as opposed to restraining measures which hare generally easily circumvented by young people. The mass media campaigns showed positive effect on attempts to quit among smokers if carried forward over time and by involving multiple communication channels (TV, internet, radio). The bans in public have little effect on smoking cessation but could improve the overall well-being of non-smokers. Heterogeneous results have been described by different studies probably because of different research methodologies, cultural aspects and the really effective implementation of the rules for each country. In conclusion, comprehensive tobacco control interventions to reduce smoking prevalence and modify the smoking behavior are recommended. Moreover, the use of e-cigarettes and heat-not-burn (HnB) products, as possible helping tool for smoke cessation, currently remains controversial.
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In diabetic patients and animal models of diabetes mellitus (DM), circulating endothelial progenitor cell (EPC) number is lower than in normoglycaemic conditions and EPC angiogenic properties are inhibited. Stromal cell derived factor-1 (SDF-1) plays a key role in bone marrow (BM) c-kit(+) stem cell mobilization into peripheral blood (PB), recruitment from PB into ischemic tissues and differentiation into endothelial cells. The aim of the present study was to examine the effect of DM in vivo and in vitro, on murine BM-derived c-kit(+) cells and on their response to SDF-1. Acute hindlimb ischemia was induced in streptozotocin-treated DM and control mice; circulating c-kit(+) cells exhibited a rapid increase followed by a return to control levels which was significantly faster in DM than in control mice. CXCR4 expression by BM c-kit(+) cells as well as SDF-1 protein levels in the plasma and in the skeletal muscle, both before and after the induction of ischemia, were similar between normoglycaemic and DM mice. However, BM-derived c-kit(+) cells from DM mice exhibited an impaired differentiation towards the endothelial phenotype in response to SDF-1; this effect was associated with diminished protein kinase phosphorylation. Interestingly, SDF-1 ability to induce differentiation of c-kit(+) cells from DM mice was restored when cells were cultured under normoglycaemic conditions whereas c-kit(+) cells from normoglycaemic mice failed to differentiate in response to SDF-1 when they were cultured in hyperglycaemic conditions. These results show that DM diminishes circulating c-kit(+) cell number following hindlimb ischemia and inhibits SDF-1-mediated AKT phosphorylation and differentiation towards the endothelial phenotype of BM-derived c-kit(+) cells.
Assuntos
Células da Medula Óssea/citologia , Quimiocina CXCL12/metabolismo , Diabetes Mellitus/metabolismo , Células Endoteliais/citologia , Regulação da Expressão Gênica , Células-Tronco/citologia , Animais , Diferenciação Celular , Separação Celular , Diabetes Mellitus Experimental/metabolismo , Isquemia/patologia , Masculino , Camundongos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-kit/biossínteseRESUMO
During cardiac development, the epicardium is the source of multipotent mesenchymal cells, which give rise to endothelial and smooth muscle cells in coronary vessels and also, possibly, to cardiomyocytes. The aim of the present study was to determine whether stem cells are retained in the adult human and murine epicardium and to investigate the regenerative potential of these cells following acute myocardial infarction. We show that c-kit(+) and CD34(+) cells can indeed be detected in human fetal and adult epicardium and that they represent 2 distinct populations. Both subsets of cells were negative for CD45, a cell surface marker that identifies the hematopoietic cell lineage. Immunofluorescence revealed that freshly isolated c-kit(+) and CD34(+) cells expressed early and late cardiac transcription factors and could acquire an endothelial phenotype in vitro. In the murine model of myocardial infarction, there was an increase in the absolute number and proliferation of epicardial c-kit(+) cells 3 days after coronary ligation; at this time point, epicardial c-kit(+) cells were identified in the subepicardial space and expressed GATA4. Furthermore, 1 week after myocardial infarction, cells coexpressing c-kit(+), together with endothelial or smooth muscle cell markers, were identified in the wall of subepicardial blood vessels. In summary, the postnatal epicardium contains a cell population with stem cell characteristics that retains the ability to give rise to myocardial precursors and vascular cells. These cells may play a role in the regenerative response to cardiac damage.
Assuntos
Endotélio Vascular/citologia , Miócitos Cardíacos/citologia , Pericárdio/citologia , Células-Tronco/citologia , Animais , Movimento Celular/fisiologia , Endotélio Vascular/embriologia , Endotélio Vascular/fisiologia , Feminino , Coração Fetal/citologia , Coração Fetal/fisiologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Miocárdio/citologia , Miócitos Cardíacos/fisiologia , Pericárdio/embriologia , Pericárdio/fisiologia , Células-Tronco/fisiologiaRESUMO
Despite enormous advances in breast cancer biology, there is an increased demand for new technologies/methods that are able to provide supplementary information to genomics and proteomics. Here, we exploit scanning force microscopy (SFM) in combination with confocal microscopy, to investigate the morphological and mechanical properties of two neoplastic cell lines: (i) MCF-7 (human breast cancer) and (ii) HeLa (human cervical carcinoma). Living and fixed cells either in phosphate buffer solution (PBS) or in air have been studied, and the viscoelastic properties (including the Young's modulus) of cells grown onto standard and modified (e.g. by fibronectin, one of the cellular matrix components) substrates have been measured. We observed different Young's modulus values, influenced by the adhesion and growth behaviour onto specific substrate surfaces.
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Neoplasias da Mama/patologia , Neoplasias da Mama/fisiopatologia , Micromanipulação/métodos , Microscopia de Força Atômica/métodos , Linhagem Celular Tumoral , Módulo de Elasticidade , Células HeLa , Humanos , Estresse Mecânico , ViscosidadeRESUMO
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease affecting motor neurons. In ALS mice, neurodegeneration is associated with the proliferative restorative attempts of ependymal stem progenitor cells (epSPCs) that normally lie in a quiescent in the spinal cord. Thus, modulation of the proliferation of epSPCs may represent a potential strategy to counteract neurodegeneration. Recent studies demonstrated that FM19G11, a hypoxia-inducible factor modulator, induces epSPC self-renewal and proliferation. The aim of the study was to investigate whether FM19G11-loaded gold nanoparticles (NPs) can affect self-renewal and proliferation processes in epSPCs isolated from G93A-SOD1 mice at disease onset. We discovered elevated levels of SOX2, OCT4, AKT1, and AKT3, key genes associated with pluripotency, self-renewal, and proliferation, in G93A-SOD1 epSPCs at the transcriptional and protein levels after treatment with FM19G11-loaded NPs. We also observed an increase in the levels of the mitochondrial uncoupling protein (UCP) gene in treated cells. FM19G11-loaded NPs treatment also affected the expression of the cell cycle-related microRNA (miR)-19a, along with its target gene PTEN, in G93A-SOD1 epSPCs. Overall our findings establish the significant impact of FM19G11-loaded NPs on the cellular pathways involved in self-renewal and proliferation in G93A-SOD1 epSPCs, thus providing an impetus to the design of novel tailored approaches to delay ALS disease progression.
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Benzamidas/farmacologia , Autorrenovação Celular/efeitos dos fármacos , Epêndima/citologia , Ouro/química , Nanopartículas Metálicas/química , Células-Tronco/citologia , Esclerose Lateral Amiotrófica , Animais , Biomarcadores/metabolismo , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos Transgênicos , MicroRNAs/genética , MicroRNAs/metabolismo , Fator 3 de Transcrição de Octâmero/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Células-Tronco Pluripotentes/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fatores de Transcrição SOXB1/metabolismo , Células-Tronco/efeitos dos fármacos , Superóxido Dismutase-1/metabolismo , Proteína Desacopladora 2/metabolismoRESUMO
High Mobility Box 1 Protein (HMGB1) is a cytokine released into the extracellular space by necrotic cells and activated macrophages in response to injury. We recently demonstrated that HMGB1 administration into the mouse heart during acute myocardial infarction induces cardiac tissue regeneration by activating resident cardiac c-kit+ cells (CSCs) and significantly enhances left ventricular function. In the present study it was analyzed the hypothesis that human cardiac fibroblasts (cFbs) exposed to HMGB1 may exert a paracrine effect on mouse and human CSCs. Human cFbs expressed the HMGB1 receptor RAGE. Luminex technology and ELISA assays revealed that HMGB1 significantly enhanced VEGF, PlGF, Mip-1alpha, IFN-gamma, GM-CSF, Il-10, Il-1beta, Il-4, Il-1ra, Il-9 and TNF-alpha in cFbs cell culture medium. HMGB1-stimulated cFbs conditioned media induced CSC migration and proliferation. These effects were significantly higher to those obtained when HMGB1 was added directly to the culture medium. In conclusion, we provide evidence that HMGB1 may act in a paracrine manner stimulating growth factor, cytokine and chemokine release by cFbs which, in turn, modulate CSC function. Via this mechanism HMGB1 may contribute to cardiac tissue regeneration.
Assuntos
Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Proteína HMGB1/farmacologia , Miocárdio/citologia , Comunicação Parácrina/efeitos dos fármacos , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Animais , Diferenciação Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Quimiocinas/metabolismo , Meios de Cultivo Condicionados , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas de Membrana , Camundongos , Miocárdio/metabolismo , Fenótipo , Proteínas/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
The use of the anthracycline epirubicin (EPI) is limited by the risk of a dilatory congestive heart failure that develops as a consequence of induction of a mitochondrial-dependent cardiomyocyte and endothelial cell apoptosis. Nitric oxide (NO) increases the antitumoral activity of several chemotherapics, while it provides protection against apoptosis induced by oxidative stress both in endothelial cells and cardiomyocytes. The aim of the present study was to investigate whether the addition of an NO-releasing moiety to a pegylated derivative of EPI (p-EPI-NO) confers to the drug a different cytotoxic profile against tumoral and normal cells. The cytotoxic profile of the drugs was investigated in Caco-2 cell line, in embryonic rat heart-derived myoblasts (H9c2), in adult cardiomyocytes, and in endothelial cells (HUVEC). p-EPI-NO was more efficient than EPI in inducing Caco-2 cell apoptosis, while it spared HUVEC, H9c2 cells and adult cardiomyocytes from EPI-induced toxicity. Exposure of cells to p-EPI-NO resulted in a NO-mediated inhibition of cellular respiration followed by mitochondrial membrane depolarization and cell death in Caco-2 cells but not in HUVEC and H9c2 cells in which mitochondrial membrane polarization was maintained at the expense of glycolytically generated ATP. These findings indicate that addition of an NO-releasing moiety to p-EPI increases the anti-neoplastic activity of the drug, while it reduces its cytotoxicity against nonneoplastic cells.
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Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Epirubicina/análogos & derivados , Óxido Nítrico/metabolismo , Polietilenoglicóis/farmacologia , Trifosfato de Adenosina/metabolismo , Animais , Células CACO-2 , Células Cultivadas , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Epirubicina/farmacologia , Humanos , Camundongos , Miócitos Cardíacos/metabolismo , Consumo de Oxigênio , RatosRESUMO
High-mobility group box 1 protein (HMGB1) is a chromatin protein that is released by inflammatory and necrotic cells. Extracellular HMGB1 signals tissue damage, stimulates the secretion of proinflammatory cytokines and chemokines, and modulates stem cell function. The present study examined exogenous HMGB1 effect on mouse left-ventricular function and myocyte regeneration after infarction. Myocardial infarction was induced in C57BL/6 mice by permanent coronary artery ligation. After 4 hours animals were reoperated and 200 ng of purified HMGB1 was administered in the peri-infarcted left ventricle. This intervention resulted in the formation of new myocytes within the infarcted portion of the wall. The regenerative process involved the proliferation and differentiation of endogenous cardiac c-kit+ progenitor cells. Circulating c-kit+ cells did not significantly contribute to HMGB1-mediated cardiac regeneration. Echocardiographic and hemodynamic parameters at 1, 2, and 4 weeks demonstrated a significant recovery of cardiac performance in HMGB1-treated mice. These effects were not observed in infarcted hearts treated either with the unrelated protein glutathione S-transferase or a truncated form of HMGB1. Thus, HMGB1 appears to be a potent inducer of myocardial regeneration following myocardial infarction.
Assuntos
Proteína HMGB1/farmacologia , Infarto do Miocárdio/fisiopatologia , Miócitos Cardíacos/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-kit/análise , Regeneração/efeitos dos fármacos , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Conexina 43/análise , Camundongos , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/fisiologia , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Função Ventricular Esquerda/efeitos dos fármacosRESUMO
We have developed an integrated microfluidic platform for producing 2-[(18)F]-fluoro-2-deoxy-D-glucose ((18)F-FDG) in continuous flow from a single bolus of radioactive isotope solution, with constant product yields achieved throughout the operation that were comparable to those reported for commercially available vessel-based synthesisers (40-80%). The system would allow researchers to obtain radiopharmaceuticals in a dose-on-demand setting within a few minutes. The flexible architecture of the platform, based on a modular design, can potentially be applied to the synthesis of other radiotracers that require a two-step synthetic approach, and may be adaptable to more complex synthetic routes by implementing additional modules. It can therefore be employed for standard synthesis protocols as well as for research and development of new radiopharmaceuticals.
Assuntos
Técnicas Analíticas Microfluídicas/métodos , Compostos Radiofarmacêuticos/síntese química , Desenho de Equipamento , Fluordesoxiglucose F18/síntese química , Humanos , Técnicas Analíticas Microfluídicas/instrumentação , Tomografia por Emissão de Pósitrons , Pressão , Hidróxido de Sódio/química , TemperaturaRESUMO
Oil bodies (OBs) are specialised organelles ubiquitously detected in plant oil seeds, which serve as lipid storage compartments. OBs consist of a hydrophobic core of triacylglycerol (TAGs), surrounded by a monolayer of phospholipids (PLs) embedded with some specific proteins with a size ranging from 0.5 to 2 µm. In this work, we report an easy method to reconstitute OBs starting from their constituents and to encapsulate lipophilic molecules, i.e. the fluorescent fluorescein isothiocyanate (FITC) and carboxyfluorescein (CF), into reconstituted OBs. This methods allowed us to produce OBs 4- to 10-fold smaller (50-200 nm) than the native one and to obtain a good recovery (about 40%) of both the fluorescent compounds used in the present work. The properties of reconstituted OBs were investigated by a combination of Brewster angle microscopy, scanning force microscopy, ζ-potential techniques. OBs were stable and formed ordered monolayers when patterned on hydrophobic substrates whereas they showed a higher tendency to aggregate into larger, coalescing OBs when were deposited onto hydrophilic substrates or at the air/water interface. Furthermore, we verified the uptake of FITC-loaded OBs by the MCF-7 breast cancer cell line. Our results indicated that OBs could be envisaged as novel carriers to deliver hydrophobic bioactive compounds.
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Corpos de Inclusão/metabolismo , Lipídeos/química , Óleos de Plantas/metabolismo , Ar , Linhagem Celular Tumoral , Corylus/química , Humanos , Espaço Intracelular/metabolismo , Microscopia de Força Atômica , Microscopia Confocal , Prunus/química , Sementes/química , Eletricidade Estática , ÁguaRESUMO
Immunofluorescence techniques on formalin fixed paraffin-embedded sections allow for the evaluation of the expression and spatial distribution of specific markers in patient tissue specimens or for monitoring the fate of labeled cells after in vivo injection. This technique suffers however from the auto-fluorescence background signal of the embedded tissue that eventually confounds the analysis. Here we show that rod-like semiconductor nanocrystals (QRs), intramuscularly injected in living mice, could be clearly detected by confocal microscopy in formalin fixed paraffin-embedded tissue sections. Despite the low amount of QRs amount injected (25 picomoles), these were clearly visible after 24 h in the muscle sections and their fluorescence signal was stronger than that of CdSe/ZnS quantum dots (QDs) similarly functionalized and in the case of QRs only, the signal lasted even after 21 days after the injection.
Assuntos
Compostos de Cádmio , Diagnóstico por Imagem/métodos , Corantes Fluorescentes , Nanopartículas , Compostos de Selênio , Semicondutores , Sulfetos , Animais , Compostos de Cádmio/administração & dosagem , Corantes Fluorescentes/administração & dosagem , Injeções Intramusculares , Luminescência , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Músculo Esquelético/metabolismo , Nanopartículas/administração & dosagem , Nanopartículas/ultraestrutura , Inclusão em Parafina , Polietilenoglicóis/química , Compostos de Selênio/administração & dosagem , Sulfetos/administração & dosagemRESUMO
Adipose-tissue-derived mesenchymal stem cells can be directed towards a myogenic phenotype in vitro by the addition of specific inductive media. However, the ability of these or other adipose-tissue-associated cells to respond to ;natural' myogenic cues such as a myogenic environment has never been investigated in detail. Here, we provide evidence that a restricted subpopulation of freshly harvested adipose-tissue-derived cells possesses an intrinsic myogenic potential and can spontaneously differentiate into skeletal muscle. Conversion of adipose-tissue-derived cells to a myogenic phenotype is enhanced by co-culture with primary myoblasts in the absence of cell contact and is maximal when the two cell types are co-cultured in the same plate. Conversely, in vitro expanded adipose-tissue-derived mesenchymal stem cells require direct contact with muscle cells to generate skeletal myotubes. Finally, we show that uncultured adipose-tissue-associated cells have a high regenerative capacity in vivo since they can be incorporated into muscle fibers following ischemia and can restore significantly dystrophin expression in mdx mice.
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Tecido Adiposo/citologia , Músculo Esquelético/citologia , Animais , Diferenciação Celular , Transplante de Células , Células Cultivadas , Técnicas de Cocultura , Distrofina/metabolismo , Células-Tronco Mesenquimais/citologia , Camundongos , Camundongos Endogâmicos mdx , Fibras Musculares Esqueléticas/citologia , Músculo Esquelético/patologia , Músculo Esquelético/fisiologia , Mioblastos Esqueléticos/citologia , Isquemia Miocárdica/patologia , Regeneração/fisiologia , Células Estromais/citologia , Células Estromais/transplanteRESUMO
Cardiac failure is a frequent cause of death in the aging human population. Telomere attrition occurs with age, and is proposed to be causal for the aging process. To determine whether telomere shortening leads to a cardiac phenotype, we studied heart function in the telomerase knockout mouse, Terc-/-. We studied Terc-/- mice at the second, G2, and fifth, G5, generation. Telomere shortening in G2 and G5 Terc-/- mice was coupled with attenuation in cardiac myocyte proliferation, increased apoptosis and cardiac myocyte hypertrophy. On a single-cell basis, telomere shortening was coincidental with increased expression of p53, indicating the presence of dysfunctional telomeres in cardiac myocytes from G5 Terc-/- mice. The impairment in cell division, the enhanced cardiac myocyte death and cellular hypertrophy, are concomitant with ventricular dilation, thinning of the wall and cardiac dysfunction. Thus, inhibition of cardiac myocyte replication provoked by telomere shortening, results in de-compensated eccentric hypertrophy and heart failure in mice. Telomere shortening with age could also contribute to cardiac failure in humans, opening the possibility for new therapies.