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1.
Proc Natl Acad Sci U S A ; 118(39)2021 09 28.
Artículo en Inglés | MEDLINE | ID: mdl-34548400

RESUMEN

The Plasmodium falciparum proteasome is a potential antimalarial drug target. We have identified a series of amino-amide boronates that are potent and specific inhibitors of the P. falciparum 20S proteasome (Pf20S) ß5 active site and that exhibit fast-acting antimalarial activity. They selectively inhibit the growth of P. falciparum compared with a human cell line and exhibit high potency against field isolates of P. falciparum and Plasmodium vivax They have a low propensity for development of resistance and possess liver stage and transmission-blocking activity. Exemplar compounds, MPI-5 and MPI-13, show potent activity against P. falciparum infections in a SCID mouse model with an oral dosing regimen that is well tolerated. We show that MPI-5 binds more strongly to Pf20S than to human constitutive 20S (Hs20Sc). Comparison of the cryo-electron microscopy (EM) structures of Pf20S and Hs20Sc in complex with MPI-5 and Pf20S in complex with the clinically used anti-cancer agent, bortezomib, reveal differences in binding modes that help to explain the selectivity. Together, this work provides insights into the 20S proteasome in P. falciparum, underpinning the design of potent and selective antimalarial proteasome inhibitors.


Asunto(s)
Compuestos de Boro/farmacología , Malaria Falciparum/tratamiento farmacológico , Plasmodium falciparum/efectos de los fármacos , Complejo de la Endopetidasa Proteasomal/química , Inhibidores de Proteasoma/farmacología , Administración Oral , Animales , Compuestos de Boro/administración & dosificación , Compuestos de Boro/química , Dominio Catalítico , Humanos , Malaria Falciparum/enzimología , Malaria Falciparum/parasitología , Ratones , Ratones Endogámicos NOD , Ratones SCID , Modelos Moleculares , Plasmodium falciparum/enzimología , Inhibidores de Proteasoma/administración & dosificación , Inhibidores de Proteasoma/química
2.
Environ Sci Technol ; 57(13): 5149-5159, 2023 04 04.
Artículo en Inglés | MEDLINE | ID: mdl-36939598

RESUMEN

We measured submicron aerosols (PM1) at a beachfront site in Texas in Spring 2021 to characterize the "background" aerosol chemical composition advecting into Texas and the factors controlling this composition. Observations show that marine "background" aerosols from the Gulf of Mexico were highly processed and acidic; sulfate was the most abundant component (on average 57% of total PM1 mass), followed by organic material (26%). These chemical characteristics are similar to those observed at other marine locations globally. However, Gulf "background" aerosols were much more polluted; the average non-refractory (NR-) PM1 mass concentration was 3-70 times higher than that observed in other clean marine atmospheres. Anthropogenic shipping emissions over the Gulf of Mexico explain 78.3% of the total measured "background" sulfate in the Gulf air. We frequently observed haze pollution in the air mass from the Gulf, with significantly elevated concentrations of sulfate, organosulfates, and secondary organic aerosol associated with sulfuric acid. Analysis suggests that aqueous oxidation of shipping emissions over the Gulf of Mexico by peroxides in the particles might potentially be an important pathway for the rapid production of acidic sulfate and organosulfates during the haze episodes under acidic conditions.


Asunto(s)
Contaminantes Atmosféricos , Sulfatos , Sulfatos/análisis , Contaminantes Atmosféricos/análisis , Golfo de México , Oxidación-Reducción , Óxidos de Azufre/análisis , Aerosoles/análisis , Material Particulado/análisis , Monitoreo del Ambiente , China
3.
Int J Mol Sci ; 24(17)2023 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-37685904

RESUMEN

Infection with hepatitis B virus (HBV) is a main risk factor for hepatocellular carcinoma (HCC). Extracellular vesicles, such as exosomes, play an important role in tumor development and metastasis, including regulation of HBV-related HCC. In this study, we have characterized exosome microRNA and proteins released in vitro from hepatitis B virus (HBV)-related HCC cell lines SNU-423 and SNU-182 and immortalized normal hepatocyte cell lines (THLE2 and THLE3) using microRNA sequencing and mass spectrometry. Bioinformatics, including functional enrichment and network analysis, combined with survival analysis using data related to HCC in The Cancer Genome Atlas (TCGA) database, were applied to examine the prognostic significance of the results. More than 40 microRNAs and 200 proteins were significantly dysregulated (p < 0.05) in the exosomes released from HCC cells in comparison with the normal liver cells. The functional analysis of the differentially expressed exosomal miRNAs (i.e., mir-483, mir-133a, mir-34a, mir-155, mir-183, mir-182), their predicted targets, and exosomal differentially expressed proteins (i.e., POSTN, STAM, EXOC8, SNX9, COL1A2, IDH1, FN1) showed correlation with pathways associated with HBV, virus activity and invasion, exosome formation and adhesion, and exogenous protein binding. The results from this study may help in our understanding of the role of HBV infection in the development of HCC and in the development of new targets for treatment or non-invasive predictive biomarkers of HCC.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/genética , Virus de la Hepatitis B , Neoplasias Hepáticas/genética , Hepatocitos
4.
Environ Res ; 212(Pt C): 113418, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35523273

RESUMEN

Studies increasingly use output from the Environmental Protection Agency's Fused Air Quality Surface Downscaler ("downscaler") model, which provides spatial predictions of daily concentrations of fine particulate matter (PM2.5) and ozone (O3) at the census tract level, to study the health and societal impacts of exposure to air pollution. Downscaler outputs have been used to show that lower income and higher minority neighborhoods are exposed to higher levels of PM2.5 and lower levels of O3. However, the uncertainty of the downscaler estimates remains poorly characterized, and it is not known if all subpopulations are benefiting equally from reliable predictions. We examined how the percent errors (PEs) of daily concentrations of PM2.5 and O3 between 2002 and 2016 at the 2010 census tract centroids across North Carolina were associated with measures of racial and educational isolation, neighborhood disadvantage, and urbanicity. Results suggest that there were socioeconomic and demographic disparities in surface concentrations of PM2.5 and O3, as well as their prediction uncertainties. Neighborhoods characterized by less reliable downscaler predictions (i.e., higher PEPM2.5 and PEO3) exhibited greater levels of aerial deprivation as well as educational isolation, and were often non-urban areas (i.e., suburban, or rural). Between 2002 and 2016, predicted PM2.5 and O3 levels decreased and O3 predictions became more reliable. However, the predictive uncertainty for PM2.5 has increased since 2010. Substantial spatial variability was observed in the temporal changes in the predictive uncertainties; educational isolation and neighborhood deprivation levels were associated with smaller increases in predictive uncertainty of PM2.5. In contrast, racial isolation was associated with a greater decline in the reliability of PM2.5 predictions between 2002 and 2016; it was associated with a greater improvement in the predictive reliability of O3 within the same time frame.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Ozono , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Demografía , Exposición a Riesgos Ambientales/análisis , Renta , North Carolina , Ozono/análisis , Material Particulado/análisis , Reproducibilidad de los Resultados , Incertidumbre
5.
Int J Mol Sci ; 23(19)2022 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-36232973

RESUMEN

Targeted delivery of drugs or other therapeutic agents through internal or external triggers has been used to control and accelerate the release from liposomal carriers in a number of studies, but relatively few utilize energy of therapeutic X-rays as a trigger. We have synthesized liposomes that are triggered by ionizing radiation (RTLs) to release their therapeutic payload. These liposomes are composed of natural egg phosphatidylethanolamine (PE), 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), cholesterol, and 1,2-disteroyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol)-2000] (DSPE-PEG-2000), and the mean size of the RTL was in the range of 114 to 133 nm, as measured by nanoparticle tracking analysis (NTA). The trigger mechanism is the organic halogen, chloral hydrate, which is known to generate free protons upon exposure to ionizing radiation. Once protons are liberated, a drop in internal pH of the liposome promotes destabilization of the lipid bilayer and escape of the liposomal contents. In proof of principle studies, we assessed RTL radiation-release of fluorescent tracers upon exposure to a low pH extracellular environment or exposure to X-ray irradiation. Biodistribution imaging before and after irradiation demonstrated a preferential uptake and release of the liposomes and their cargo at the site of local tumor irradiation. Finally, a potent metabolite of the commonly used chemotherapy irinotecan, SN-38, was loaded into RTL along with near infrared (NIR) fluorescent dyes for imaging studies and measuring tumor cell cytotoxicity alone or combined with radiation exposure, in vitro and in vivo. Fully loaded RTLs were found to increase tumor cell killing with radiation in vitro and enhance tumor growth delay in vivo after three IV injections combined with three, 5 Gy local tumor radiation exposures compared to either treatment modality alone.


Asunto(s)
Liposomas , Neoplasias , Hidrato de Cloral , Colesterol/química , Colorantes Fluorescentes , Halógenos , Humanos , Irinotecán , Membrana Dobles de Lípidos/química , Liposomas/química , Neoplasias/tratamiento farmacológico , Neoplasias/radioterapia , Fosfatidiletanolaminas/química , Polietilenglicoles/química , Protones , Distribución Tisular
6.
Angiogenesis ; 24(3): 597-611, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33629198

RESUMEN

Antibiotic-induced microbial imbalance, or dysbiosis, has systemic and long-lasting effects on the host and response to cancer therapies. However, the effects on tumor endothelial cells are largely unknown. Therefore, the goal of the current study was to generate matched B16-F10 melanoma associated endothelial cell lines isolated from mice with and without antibiotic-induced dysbiosis. After validating endothelial cell markers on a genomic and proteomic level, functional angiogenesis assays (i.e., migration and tube formation) also confirmed their vasculature origin. Subsequently, we found that tumor endothelial cells derived from dysbiotic mice (TEC-Dys) were more sensitive to ionizing radiotherapy in the range of clinically-relevant hypofractionated doses, as compared to tumor endothelial cells derived from orthobiotic mice (TEC-Ortho). In order to identify tumor vasculature-associated drug targets during dysbiosis, we used tandem mass tag mass spectroscopy and focused on the statistically significant cellular membrane proteins overexpressed in TEC-Dys. By these criteria c-Met was the most differentially expressed protein, which was validated histologically by comparing tumors with or without dysbiosis. Moreover, in vitro, c-Met inhibitors Foretinib, Crizotinib and Cabozantinib were significantly more effective against TEC-Dys than TEC-Ortho. In vivo, Foretinib inhibited tumor growth to a greater extent during dysbiosis as compared to orthobiotic conditions. Thus, we surmise that tumor response in dysbiotic patients may be greatly improved by targeting dysbiosis-induced pathways, such as c-Met, distinct from the many targets suppressed due to dysbiosis.


Asunto(s)
Disbiosis , Células Endoteliales/enzimología , Melanoma Experimental , Neovascularización Patológica , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-met , Animales , Disbiosis/enzimología , Disbiosis/microbiología , Melanoma Experimental/irrigación sanguínea , Melanoma Experimental/enzimología , Melanoma Experimental/microbiología , Melanoma Experimental/terapia , Ratones , Neovascularización Patológica/enzimología , Neovascularización Patológica/microbiología , Neovascularización Patológica/terapia , Proteínas Proto-Oncogénicas c-met/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-met/metabolismo , Radioterapia
7.
Mol Cell Biochem ; 476(4): 1691-1704, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33423165

RESUMEN

Mesenchymal stem cell (MSC) exosomes may limit cardiac injury, and even reverse cardiac damage in animal models of ischemia. To understand exosome-mediated improvement in cardiac function we examined the proteomic alternations in the MSC exosome-treated mice hearts subjected to left coronary artery (LCA) ligation, with particular emphasis on peri-infarct areas. At 7 days after LCA ligation, left ventricular end systolic thickness, infarct size and survival of mice were studied. Mass spectrometric analysis of infarct and peri-infarct areas was carried out. Expression of inflammatory markers (LOX-1 and NLRP3) and cell death markers (Bax, Bcl-2, Caspases 1 and 3 and GSDMD) were investigated by Western blots and immunofluorescence. Proteomic analysis of the infarct and peri-infarct areas in saline-treated hearts revealed differentially expressed proteins involved in inflammation and apoptotic cell death, while showing depletion of processes governing cell death. Exosome treatment significantly improved the proteomic profile in both infarct and peri-infarct areas, more so in the peri-infarct areas. The infarct size was smaller (9 ± 1%), and cardiac contractile function (fractional shortening) was preserved in the exosome-treated mice (28 ± 2%). Survival of exosome-treated mice was also better. White blood cell accumulation in and around the infarct area, expression of LOX-1 and NLRP3 inflammasome, and markers of cell death (cleaved Caspase-3, Caspase-1, GSDMD, Bcl-2 and Bax) were dramatically reduced by MSC exosome treatment (all p < 0.01). In cultured primary mouse cardiomyocytes, treatment with MSC exosomes essentially reversed inflammation-induced pro-apoptotic and inflammatory signals (p < 0.01). MSC exosomes exert their cardioprotective effects by suppressing inflammation and pro-apoptotic processes, particularly in the peri-infarct areas, resulting in preservation of cardiac function after LCA ligation.


Asunto(s)
Exosomas , Células Madre Mesenquimatosas/metabolismo , Infarto del Miocardio , Animales , Línea Celular Transformada , Exosomas/metabolismo , Exosomas/patología , Exosomas/trasplante , Humanos , Masculino , Células Madre Mesenquimatosas/patología , Ratones , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Infarto del Miocardio/prevención & control
8.
Stat Med ; 40(22): 4850-4871, 2021 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-34132416

RESUMEN

Social and environmental stressors are crucial factors in child development. However, there exists a multitude of measurable social and environmental factors-the effects of which may be cumulative, interactive, or null. Using a comprehensive cohort of children in North Carolina, we study the impact of social and environmental variables on 4th end-of-grade exam scores in reading and mathematics. To identify the essential factors that predict these educational outcomes, we design new tools for Bayesian linear variable selection using decision analysis. We extract a predictive optimal subset of explanatory variables by coupling a loss function with a novel model-based penalization scheme, which leads to coherent Bayesian decision analysis and empirically improves variable selection, estimation, and prediction on simulated data. The Bayesian linear model propagates uncertainty quantification to all predictive evaluations, which is important for interpretable and robust model comparisons. These predictive comparisons are conducted out-of-sample with a customized approximation algorithm that avoids computationally intensive model refitting. We apply our variable selection techniques to identify the joint collection of social and environmental stressors-and their interactions-that offer clear and quantifiable improvements in prediction of reading and mathematics exam scores.


Asunto(s)
Exposición a Riesgos Ambientales , Teorema de Bayes , Niño , Estudios de Cohortes , Exposición a Riesgos Ambientales/efectos adversos , Humanos , North Carolina
9.
Purinergic Signal ; 17(3): 399-410, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-33970408

RESUMEN

Systemic pools of ATP are elevated in individuals homozygous for cystic fibrosis (CF) as evidenced by elevated blood and plasma ATP levels. This elevated ATP level seems to provide benefit in the presence of advanced solid tumors (Abraham et al., Nature Medicine 2(5):593-596, 1996). We published in this journal a paper showing that IV ATP can elevate the depleted ATP pools of advanced cancer patients up to levels found in CF patients with subsequent clinical, biochemical, and quality of life (QOL) improvements (Rapaport et al., Purinergic Signalling 11(2): 251-262, 2015). We hypothesize that the elevated ATP levels seen in CF patients may be benefiting CF patients in another way: by improving their survival after contracting COVID-19. We discuss here the reasoning behind this hypothesis and suggest how these findings might be applied clinically in the general population.


Asunto(s)
Adenosina Trifosfato/metabolismo , COVID-19 , Fibrosis Quística/complicaciones , Fibrosis Quística/metabolismo , Fibrosis Quística/fisiopatología , Humanos , SARS-CoV-2
10.
Atmos Environ (1994) ; 2442021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33414674

RESUMEN

Understanding the drivers for high ozone (O3) and atmospheric particulate matter (PM) concentrations is a pressing issue in urban air quality, as this understanding informs decisions for control and mitigation of these key pollutants. The Houston, TX metropolitan area is an ideal location for studying the intersection between O3 and atmospheric secondary organic carbon (SOC) production due to the diversity of source types (urban, industrial, and biogenic) and the on- and off-shore cycling of air masses over Galveston Bay, TX. Detailed characterization of filter-based samples collected during Deriving Information on Surface Conditions from Column and VERtically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) Houston field experiment in September 2013 were used to investigate sources and composition of organic carbon (OC) and potential relationships between daily maximum 8 h average O3 and PM. The current study employed a novel combination of chemical mass balance modeling defining primary (i.e. POC) versus secondary (i.e. SOC) organic carbon and radiocarbon (14C) for apportionment of contemporary and fossil carbon. The apportioned sources include contemporary POC (biomass burning [BB], vegetative detritus), fossil POC (motor vehicle exhaust), biogenic SOC and fossil SOC. The filter-based results were then compared with real-time measurements by aerosol mass spectrometry. With these methods, a consistent urban background of contemporary carbon and motor vehicle exhaust was observed in the Houston metropolitan area. Real-time and filter-based characterization both showed that carbonaceous aerosols in Houston was highly impacted by SOC or oxidized OC, with much higher contributions from biogenic than fossil sources. However, fossil SOC concentration and fractional contribution had a stronger correlation with daily maximum 8 h average O3, peaking during high PM and O3 events. The results indicate that point source emissions processed by on- and off-shore wind cycles likely contribute to peak events for both PM and O3 in the greater Houston metropolitan area.

11.
Int J Mol Sci ; 22(10)2021 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-34069542

RESUMEN

Exosomes are small vesicles with an average diameter of 100 nm that are produced by many, if not all, cell types. Exosome cargo includes lipids, proteins, and nucleic acids arranged specifically in the endosomes of donor cells. Exosomes can transfer the donor cell components to target cells and can affect cell signaling, proliferation, and differentiation. Important new information about exosomes' remote communication with other cells is rapidly being accumulated. Recent data indicates that the results of this communication depend on the donor cell type and the environment of the host cell. In the field of cancer research, major questions remain, such as whether tumor cell exosomes are equally taken up by cancer cells and normal cells and whether exosomes secreted by normal cells are specifically taken up by other normal cells or also tumor cells. Furthermore, we do not know how exosome uptake is made selective, how we can trace exosome uptake selectivity, or what the most appropriate methods are to study exosome uptake and selectivity. This review will explain the effect of exosome source and the impact of the donor cell growth environment on tumor and normal cell interaction and communication. The review will also summarize the methods that have been used to label and trace exosomes to date.


Asunto(s)
Comunicación Celular/fisiología , Exosomas/fisiología , Transporte Biológico/fisiología , Línea Celular , Línea Celular Tumoral , Proliferación Celular/fisiología , Endosomas/fisiología , Exosomas/metabolismo , Humanos , Transducción de Señal/fisiología
12.
Environ Sci Technol ; 54(4): 2133-2142, 2020 02 18.
Artículo en Inglés | MEDLINE | ID: mdl-31995368

RESUMEN

Diverse urban air pollution sources contribute to spatially variable atmospheric concentrations, with important public health implications. Mobile monitoring shows promise for understanding spatial pollutant patterns, yet it is unclear whether uncertainties associated with temporally sparse sampling and instrument performance limit our ability to identify locations of elevated pollution. To address this question, we analyze 9 months of repeated weekday daytime on-road mobile measurements of black carbon (BC), particle number (PN), and nitrogen oxide (NO, NO2) concentrations within 24 census tracts across Houston, Texas. We quantify persistently elevated, intermittent, and extreme concentration behaviors at 50 m road segments on surface streets and 90 m segments on highways relative to median statistics across the entire sampling domain. We find elevated concentrations above uncertainty levels (±40%) within portions of every census tract, with median concentration increases ranging from 2 to 3× for NO2, and >9× for NO. In contrast, PN exhibits elevated concentrations of 1.5-2× the domain-wide median and distinct spatial patterns relative to other pollutants. Co-located elevated concentrations of primary combustion tracers (BC and NOx) near 30% of metal recycling and concrete batch plant facilities within our sampled census tracts are comparable to those measured within 200 m of highways. Our results demonstrate how extensive mobile monitoring across multiple census tracts can quantitatively characterize urban air pollution source patterns and are applicable to developing effective source mitigation policies.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Ambientales , Monitoreo del Ambiente , Material Particulado , Texas
13.
Environ Sci Technol ; 53(9): 4977-4987, 2019 05 07.
Artículo en Inglés | MEDLINE | ID: mdl-31002496

RESUMEN

Aerosol phase state is critical for quantifying aerosol effects on climate and air quality. However, significant challenges remain in our ability to predict and quantify phase state during its evolution in the atmosphere. Herein, we demonstrate that aerosol phase (liquid, semisolid, solid) exhibits a diel cycle in a mixed forest environment, oscillating between a viscous, semisolid phase state at night and liquid phase state with phase separation during the day. The viscous nighttime particles existed despite higher relative humidity and were independently confirmed by bounce factor measurements and atomic force microscopy. High-resolution mass spectrometry shows the more viscous phase state at night is impacted by the formation of terpene-derived and higher molecular weight secondary organic aerosol (SOA) and smaller inorganic sulfate mass fractions. Larger daytime particulate sulfate mass fractions, as well as a predominance of lower molecular weight isoprene-derived SOA, lead to the liquid state of the daytime particles and phase separation after greater uptake of liquid water, despite the lower daytime relative humidity. The observed diel cycle of aerosol phase should provoke rethinking of the SOA atmospheric lifecycle, as it suggests diurnal variability in gas-particle partitioning and mixing time scales, which influence aerosol multiphase chemistry, lifetime, and climate impacts.


Asunto(s)
Atmósfera , Sulfatos , Aerosoles , Química Orgánica , Bosques
14.
Exp Cell Res ; 372(1): 16-24, 2018 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-30205087

RESUMEN

Hepatocellular carcinoma (HCC) is a densely vascularized tumor that is highly dependent on angiogenic pathways to direct arterial blood flow to the growing neoplasm, though little is known about how the interaction of tumor and endothelial cells drives these processes and the degree of clinical importance. To this end, we examined the intercellular cross-talk between HepG2 (human HCC) and human endothelial progenitor cells (EPC) in a co-culture system that mimics some aspects of initial tumor parenchyma and stroma interactions. The results showed that the remote cell-to-cell (paracrine) interactions between HepG2 cells and EPC play a critical role in the differentiation and angiogenic activity of endothelial cells, possibly through intercellular signaling function of the exosomes released in the medium by HepG2 cells. The tumor-cell activated phenotype of EPC was associated with increased migration and elevated expression of ephrin-B2, and Delta-like 4 ligand (DLL4). Furthermore, ephrin-B2 was found to be overexpressed in HCC and cholangiocarcinoma tissue samples taken from humans. Overall, our results demonstrate that ephrin-B2 and Dll4 mediated co-dependence of HCC and EPC intercellular crosstalk in the initial stages of HCC establishment and development, a promising target for new clinical strategies.


Asunto(s)
Células Progenitoras Endoteliales/metabolismo , Efrina-B2/metabolismo , Exosomas/metabolismo , Regulación Neoplásica de la Expresión Génica , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Modelos Biológicos , Comunicación Paracrina/genética , Proteínas Adaptadoras Transductoras de Señales , Proteínas de Unión al Calcio , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Muerte Celular , Movimiento Celular , Técnicas de Cocultivo , Colágeno/química , Medios de Cultivo Condicionados/química , Medios de Cultivo Condicionados/farmacología , Medio de Cultivo Libre de Suero/química , Cámaras de Difusión de Cultivos , Combinación de Medicamentos , Células Progenitoras Endoteliales/citología , Células Progenitoras Endoteliales/efectos de los fármacos , Efrina-B2/genética , Exosomas/química , Células Hep G2 , Humanos , Péptidos y Proteínas de Señalización Intercelular/genética , Laminina/química , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Proteoglicanos/química , Transducción de Señal , Microambiente Tumoral
15.
Exp Cell Res ; 370(2): 426-433, 2018 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-29981341

RESUMEN

A simple and reproducible procedure was developed to measure the volume of liquid microinjected into cells. A calibration curve of droplet fluorescence intensity versus volume was constructed by injecting a fluorescent dextran solution through a 125-150 µm diameter micropipette into an oil-filled culture dish to create a spray of varied-sized droplets. The droplets retained a spherical shape because they were in an oil medium and they settled onto a glass surface coated with a superhydrophobic surface. Fluorescent micrographs of the droplets were obtained and analyzed with Image-J software to quantify the fluorescence intensity and radius of each spherical droplet to produce the calibration curve. Subsequently, Dut-145 human prostate carcinoma cells were microinjected with the same fluorescent dextran solution and fluorescent micrographs of the cells were obtained using the identical exposure conditions used to photograph the droplets. The measured fluorescence intensity of the microinjected cells was entered into the formula for the regression line that was fit to the calibration curve allowing determination of the volume of solution injected into each cell. Thus, a mixture consisting of known concentrations of a test material of test material (macromolecules, drugs, etc.) and a fluorescent dextran, volumetric, tracer can be used to quantify the relationship between the amount of a microinjected material and subsequent effects on cells.


Asunto(s)
Calibración , Microinyecciones , Microscopía Fluorescente , Línea Celular Tumoral , Dextranos , Fluorescencia , Colorantes Fluorescentes/metabolismo , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Microscopía Fluorescente/métodos , Propiedades de Superficie
16.
Carcinogenesis ; 39(9): 1117-1126, 2018 09 21.
Artículo en Inglés | MEDLINE | ID: mdl-29939201

RESUMEN

Methionine dependency describes the characteristic rapid in vitro death of most tumor cells in the absence of methionine. Combining chemotherapy with dietary methionine deprivation [methionine-deficient diet (MDD)] at tolerable levels has vast potential in tumor treatment; however, it is limited by MDD-induced toxicity during extended deprivation. Recent advances in imaging and irradiation delivery have created the field of stereotactic body radiotherapy (SBRT), where fewer large-dose fractions delivered in less time result in increased local-tumor control, which could be maximally synergistic with an MDD short course. Identification of the lowest effective methionine dietary intake not associated with toxicity will further enhance the cancer therapy potential. In this study, we investigated the effects of MDD and methionine-restricted diet (MRD) in primary and metastatic melanoma models in combination with radiotherapy (RT). In vitro, MDD dose-dependently sensitized mouse and human melanoma cell lines to RT. In vivo in mice, MDD substantially potentiated the effects of RT by a significant delay in tumor growth, in comparison with administering MDD or RT alone. The antitumor effects of an MDD/RT approach were due to effects on one-carbon metabolism, resulting in impaired methionine biotransformation via downregulation of Mat2a, which encodes methionine adenosyltransferase 2A. Furthermore, and probably most importantly, MDD and MRD substantially diminished metastatic potential; the antitumor MRD effects were not associated with toxicity to normal tissue. Our findings suggest that modulation of methionine intake holds substantial promise for use with short-course SBRT for cancer treatment.


Asunto(s)
Antineoplásicos/farmacología , Melanoma/dietoterapia , Melanoma/patología , Metionina Adenosiltransferasa/biosíntesis , Metionina/farmacología , Animales , Antineoplásicos/administración & dosificación , Línea Celular Tumoral , Humanos , Masculino , Metionina/administración & dosificación , Metionina/metabolismo , Ratones , Ratones Endogámicos C57BL , Metástasis de la Neoplasia/patología
17.
Angiogenesis ; 21(3): 425-532, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29766399

RESUMEN

The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference.


Asunto(s)
Bioensayo/métodos , Neoplasias , Neovascularización Patológica , Animales , Bioensayo/instrumentación , Guías como Asunto , Humanos , Ratones , Neoplasias/irrigación sanguínea , Neoplasias/metabolismo , Neoplasias/patología , Neovascularización Patológica/metabolismo , Neovascularización Patológica/patología
18.
BMC Microbiol ; 18(1): 227, 2018 12 27.
Artículo en Inglés | MEDLINE | ID: mdl-30591021

RESUMEN

BACKGROUND: Here we investigated the influence of different stabilization and storage strategies on the quality and composition of the fecal microbial community. Namely, same-day isolated murine DNA was compared to samples stored for 1 month in air at ambient temperature, with or without preservative buffers (i.e. EDTA and lysis buffer), different temperatures (i.e. 4 °C, - 20 °C, and - 80 °C), and hypoxic conditions. RESULTS: Only storage in lysis buffer significantly reduced DNA content, yet without integrity loss. Storage in EDTA affected alpha diversity the most, which was also reflected in cluster separation. Distinct changes were also seen in the phyla and bacterial species abundance per storage strategy. Metabolic function analysis showed 22 pathways not significantly affected by storage conditions, whereas the tyrosine metabolism pathway was significantly changed in all strategies except by EDTA. CONCLUSION: Each long-term storage strategy introduced a unique post-collection bias, which is important to take into account when interpreting data.


Asunto(s)
Bacterias/aislamiento & purificación , Microbiota , Preservación Biológica/métodos , Animales , Bacterias/clasificación , Bacterias/genética , Heces/microbiología , Ratones , Manejo de Especímenes , Temperatura
19.
Int J Hyperthermia ; 34(1): 19-29, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28540812

RESUMEN

PURPOSE: To demonstrate delivery of Au nanocages to cells using the galectin-1 binding peptide anginex (Ax) and to demonstrate the value of this targeting for selective in vitro photothermal cell killing. MATERIALS AND METHODS: Au nanocages were synthesised, coated with polydopamine (PDA), and conjugated with Ax. Tumour and endothelial cell viability was measured with and without laser irradiation. Photoacoustic (PA) mapping and PA flow cytometry were used to confirm cell targeting in vitro and in tissue slices ex vivo. RESULTS: Cell viability was maintained at ≥50% at 100 pM suggesting low toxicity of the nanocage alone. Combining the targeted construct (25 pM) with low power 808 nm laser irradiation for 10-20 min (a duration previously shown to induce rapid and sustained heating of Au nanocages [AuNC] in solution), resulted in over 50% killing of endothelial and tumour cells. In contrast, the untargeted construct combined with laser irradiation resulted in negligible cell killing. We estimate approximately 6 × 104 peptides were conjugated to each nanocage, which also resulted in inhibition of cell migration. Binding of the targeted nanocage reached a plateau after three hours, and cell association was 20-fold higher than non-targeted nanocages both in vitro and ex vivo on tumour tissue slices. A threefold increase in tumour accumulation was observed in preliminary in vivo studies. CONCLUSIONS: These studies demonstrate Ax's potential as an effective targeting agent for Au-based theranostics to tumour and endothelial cells, enabling photothermal killing. This platform further suggests potential for multimodal in vivo therapy via next-generation drug-loaded nanocages.


Asunto(s)
Galectina 1/metabolismo , Oro/metabolismo , Nanoestructuras/química , Fototerapia/métodos , Animales , Ratones , Ratones Endogámicos BALB C
20.
Int J Mol Sci ; 19(3)2018 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-29562695

RESUMEN

Galectins are a family of small, highly conserved, molecular effectors that mediate various biological processes, including chemotaxis and angiogenesis, and that function by interacting with various cell surface glycoconjugates, usually targeting ß-galactoside epitopes. Because of their significant involvement in various biological functions and pathologies, galectins have become a focus of therapeutic discovery for clinical intervention against cancer, among other pathological disorders. In this review, we focus on understanding galectin structure-function relationships, their mechanisms of action on the molecular level, and targeting them for therapeutic intervention against cancer.


Asunto(s)
Galectinas/metabolismo , Terapia Molecular Dirigida , Animales , Carbohidratos/química , Quimioterapia Combinada , Galectinas/química , Humanos
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