Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Entropy (Basel) ; 23(3)2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33652826

RESUMO

Cellular contacts modify the way cells migrate in a cohesive group with respect to a free single cell. The resulting motion is persistent and correlated, with cells' velocities self-aligning in time. The presence of a dense agglomerate of cells makes the application of single particle tracking techniques to define cells dynamics difficult, especially in the case of phase contrast images. Here, we propose an original pipeline for the analysis of phase contrast images of the wound healing scratch assay acquired in time-lapse, with the aim of extracting single particle trajectories describing the dynamics of the wound closure. In such an approach, the membrane of the cells at the border of the wound is taken as a unicum, i.e., the wound edge, and the dynamics is described by the stochastic motion of an ensemble of points on such a membrane, i.e., pseudo-particles. For each single frame, the pipeline of analysis includes: first, a texture classification for separating the background from the cells and for identifying the wound edge; second, the computation of the coordinates of the ensemble of pseudo-particles, chosen to be uniformly distributed along the length of the wound edge. We show the results of this method applied to a glioma cell line (T98G) performing a wound healing scratch assay without external stimuli. We discuss the efficiency of the method to assess cell motility and possible applications to other experimental layouts, such as single cell motion. The pipeline is developed in the Python language and is available upon request.

2.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2520-2523, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018519

RESUMO

Non-contact galvanotaxis as a way to drive the cells migration could be a promising tool for a variety of biomedical applications, such as wound healing control, avoiding the interaction between electrodes and cell cultures. To this regard, the efficacy of this electrical stimulus application has to be deeper studied to control physiological migratory phenomena in a remote way.Aim of this work is to provide an experimental investigation on the mobility of cells exposed to a static electric field in a "noncontact" mode, supported by a suitable modeling of the electric field distribution inside the experimental setup. In particular, scratch assays have been carried out placing the electrodes outside the cells medium support and changing the cells holder to study more than one configuration.Clinical Relevance- In this study the in vitro experiments on the non-contact galvanotaxis, together with the numerical simulations of the exposure setup, provide a way to investigate the effects that could affect an electrically drive cell migration.


Assuntos
Eletricidade , Resposta Táctica , Bioensaio , Movimento Celular , Eletricidade Estática
3.
Aging (Albany NY) ; 10(11): 3148-3160, 2018 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-30398975

RESUMO

Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare genetic disorder wherein symptoms resembling aspects of aging are manifested at a very early age. It is a genetic condition that occurs due to a de novo mutation in the LMNA gene encoding for the nuclear structural protein lamin A. The lamin family of proteins are thought to be involved in nuclear stability, chromatin structure and gene expression and this leads to heavy effects on the regulation and functionality of the cell machinery. The functional role of the large-conductance calcium-activated potassium channels (BKCa) is still unclear, but has been recently described a strong relationship with their membrane expression, progerin nuclear levels and the ageing process. In this study, we found that: i) the outward potassium membrane current amplitude and the fluorescence intensity of the BKCa channel probe showed higher values in human dermal fibroblast obtained from patients affected by HGPS if compared to that from healthy young subjects; ii) this result appears to correlate with a basic cellular activity such as the replicative boost. We suggest that studying the HGPS also from the electrophysiological point of view might reveal new clues about the normal process of aging.


Assuntos
Membrana Celular/metabolismo , Fibroblastos/metabolismo , Canais de Potássio Ativados por Cálcio de Condutância Alta/metabolismo , Progéria/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Adesão Celular , Proliferação de Células , Criança , Regulação da Expressão Gênica , Humanos , Lamina Tipo A/genética , Canais de Potássio Ativados por Cálcio de Condutância Alta/genética , Progéria/classificação , Adulto Jovem
4.
Nat Commun ; 9(1): 4514, 2018 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-30375513

RESUMO

We characterize different tumour types in search for multi-tumour drug targets, in particular aiming for drug repurposing and novel drug combinations. Starting from 11 tumour types from The Cancer Genome Atlas, we obtain three clusters based on transcriptomic correlation profiles. A network-based analysis, integrating gene expression profiles and protein interactions of cancer-related genes, allows us to define three cluster-specific signatures, with genes belonging to NF-κB signaling, chromosomal instability, ubiquitin-proteasome system, DNA metabolism, and apoptosis biological processes. These signatures have been characterized by different approaches based on mutational, pharmacological and clinical evidences, demonstrating the validity of our selection. Moreover, we define new pharmacological strategies validated by in vitro experiments that show inhibition of cell growth in two tumour cell lines, with significant synergistic effect. Our study thus provides a list of genes and pathways that could possibly be used, singularly or in combination, for the design of novel treatment strategies.


Assuntos
Redes Reguladoras de Genes , Genômica , Neoplasias/tratamento farmacológico , Mapas de Interação de Proteínas , Proteômica , Apoptose/genética , Instabilidade Cromossômica/genética , DNA/metabolismo , Reposicionamento de Medicamentos , Genes Neoplásicos , Ensaios de Triagem em Larga Escala , Humanos , Terapia de Alvo Molecular , NF-kappa B/genética , NF-kappa B/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Complexo de Endopeptidases do Proteassoma/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Transdução de Sinais , Transcriptoma , Ubiquitina/genética , Ubiquitina/metabolismo
5.
PLoS One ; 13(6): e0199312, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29958291

RESUMO

Radiation therapy is a useful and standard tumor treatment strategy. Despite recent advances in delivery of ionizing radiation, survival rates for some cancer patients are still low because of recurrence and radioresistance. This is why many novel approaches have been explored to improve radiotherapy outcome. Some strategies are focused on enhancement of accuracy in ionizing radiation delivery and on the generation of greater radiation beams, for example with a higher dose rate. In the present study we proposed an in vitro research of the biological effects of very high dose rate beam on SK-Mel28 and A375, two radioresistant human melanoma cell lines. The beam was delivered by a pulsed plasma device, a "Mather type" Plasma Focus for medical applications. We hypothesized that this pulsed X-rays generator is significantly more effective to impair melanoma cells survival compared to conventional X-ray tube. Very high dose rate treatments were able to reduce clonogenic efficiency of SK-Mel28 and A375 more than the X-ray tube and to induce a greater, less easy-to-repair DNA double-strand breaks. Very little is known about biological consequences of such dose rate. Our characterization is preliminary but is the first step toward future clinical considerations.


Assuntos
Melanoma/radioterapia , Tolerância a Radiação/efeitos da radiação , Radioterapia/métodos , Linhagem Celular Tumoral , Humanos , Doses de Radiação , Radiação Ionizante
6.
Sci Rep ; 7(1): 6005, 2017 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-28729616

RESUMO

Many studies investigated age-related changes in gene expression of different tissues, with scarce agreement due to the high number of affecting factors. Similarly, no consensus has been reached on which genes change expression as a function of age and not because of environment. In this study we analysed gene expression of T lymphocytes from 27 healthy monozygotic twin couples, with ages ranging over whole adult lifespan (22 to 98 years). This unique experimental design allowed us to identify genes involved in normative aging, which expression changes independently from environmental factors. We obtained a transcriptomic signature with 125 genes, from which chronological age can be estimated. This signature has been tested in two datasets of same cell type hybridized over two different platforms, showing a significantly better performance compared to random signatures. Moreover, the same signature was applied on a dataset from a different cell type (human muscle). A lower performance was obtained, indicating the possibility that the signature is T cell-specific. As a whole our results suggest that this approach can be useful to identify age-modulated genes.


Assuntos
Perfilação da Expressão Gênica , Linfócitos T/metabolismo , Transcriptoma , Gêmeos Monozigóticos/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/genética , Interação Gene-Ambiente , Estudos de Associação Genética , Genoma Humano , Humanos , Longevidade/genética , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Linfócitos T/imunologia , Adulto Jovem
7.
ACS Appl Mater Interfaces ; 9(8): 6679-6689, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28150491

RESUMO

PEDOT: PSS is a highly conductive material with good thermal and chemical stability and enhanced biocompatibility that make it suitable for bioengineering applications. The electrical control of the oxidation state of PEDOT:PSS films allows modulation of peculiar physical and chemical properties of the material, such as topography, wettability, and conductivity, and thus offers a possible route for controlling cellular behavior. Through the use of (i) the electrophysiological response of the plasma membrane as a biosensor of the ionic availability; (ii) relative abundance around the cells via X-ray spectroscopy; and (iii) atomic force microscopy to monitor PEDOT:PSS film thickness relative to its oxidation state, we demonstrate that redox processes confer to PEDOT:PSS the property to modify the ionic environment at the film-liquid interface through a "sponge-like" effect on ions. Finally, we show how this property offers the capability to electrically control central cellular properties such as viability, substrate adhesion, and growth, paving the way for novel bioelectronics and biotechnological applications.


Assuntos
Potenciais da Membrana , Compostos Bicíclicos Heterocíclicos com Pontes , Proliferação de Células , Condutividade Elétrica , Polímeros
8.
BMC Bioinformatics ; 17(Suppl 12): 341, 2016 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-28185561

RESUMO

BACKGROUND: Detecting somatic mutations in whole exome sequencing data of cancer samples has become a popular approach for profiling cancer development, progression and chemotherapy resistance. Several studies have proposed software packages, filters and parametrizations. However, many research groups reported low concordance among different methods. We aimed to develop a pipeline which detects a wide range of single nucleotide mutations with high validation rates. We combined two standard tools - Genome Analysis Toolkit (GATK) and MuTect - to create the GATK-LODN method. As proof of principle, we applied our pipeline to exome sequencing data of hematological (Acute Myeloid and Acute Lymphoblastic Leukemias) and solid (Gastrointestinal Stromal Tumor and Lung Adenocarcinoma) tumors. We performed experiments on simulated data to test the sensitivity and specificity of our pipeline. RESULTS: The software MuTect presented the highest validation rate (90 %) for mutation detection, but limited number of somatic mutations detected. The GATK detected a high number of mutations but with low specificity. The GATK-LODN increased the performance of the GATK variant detection (from 5 of 14 to 3 of 4 confirmed variants), while preserving mutations not detected by MuTect. However, GATK-LODN filtered more variants in the hematological samples than in the solid tumors. Experiments in simulated data demonstrated that GATK-LODN increased both specificity and sensitivity of GATK results. CONCLUSION: We presented a pipeline that detects a wide range of somatic single nucleotide variants, with good validation rates, from exome sequencing data of cancer samples. We also showed the advantage of combining standard algorithms to create the GATK-LODN method, that increased specificity and sensitivity of GATK results. This pipeline can be helpful in discovery studies aimed to profile the somatic mutational landscape of cancer genomes.


Assuntos
Exoma , Genômica/métodos , Neoplasias/genética , Polimorfismo de Nucleotídeo Único , Algoritmos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Mutação , Sensibilidade e Especificidade , Software
9.
ACS Appl Mater Interfaces ; 7(32): 17993-8003, 2015 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-26208175

RESUMO

UNLABELLED: Conducting polymers are promising materials for tissue engineering applications, since they can both provide a biocompatible scaffold for physical support of living cells, and transmit electrical and mechanical stimuli thanks to their electrical conductivity and reversible doping. In this work, thin films of one of the most promising materials for bioelectronics applications, poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) ( PEDOT: PSS), are prepared using two different techniques, spin coating and electrochemical polymerization, and their oxidation state is subsequently changed electrochemically with the application of an external bias. The electrochemical properties of these different types of PEDOT: PSS are studied through cyclic voltammetry and spectrophotometry to assess the effectiveness of the oxidation process and its stability over time. Their surface physical properties and their dependence on the redox state of PEDOT: PSS are investigated using atomic force microscopy (AFM), water contact angle goniometry and sheet resistance measurements. Finally, human glioblastoma multiforme cells (T98G) and primary human dermal fibroblasts (hDF) are cultured on PEDOT: PSS films with different oxidation states, finding that the effect of the substrate on the cell growth rate is strongly cell-dependent: T98G growth is enhanced by the reduced samples, while hDF growth is more effective only on the oxidized substrates that show a strong chemical interaction with the cell culture medium.


Assuntos
Técnicas Eletroquímicas , Poliestirenos/química , Tiofenos/química , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Humanos , Microscopia de Força Atômica , Oxirredução , Poliestirenos/farmacologia , Espectrofotometria , Propriedades de Superfície , Tiofenos/farmacologia , Molhabilidade
10.
Mech Ageing Dev ; 151: 45-53, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26209580

RESUMO

MARK-AGE aims at the identification of biomarkers of human aging capable of discriminating between the chronological age and the effective functional status of the organism. To achieve this, given the structure of the collected data, a proper statistical analysis has to be performed, as the structure of the data are non trivial and the number of features under study is near to the number of subjects used, requiring special care to avoid overfitting. Here we described some of the possible strategies suitable for this analysis. We also include a description of the main techniques used, to explain and justify the selected strategies. Among other possibilities, we suggest to model and analyze the data with a three step strategy.


Assuntos
Envelhecimento , Bases de Dados Factuais , Processamento Eletrônico de Dados/métodos , Modelos Teóricos , Feminino , Humanos , Masculino , Processos Estocásticos
11.
Bioelectromagnetics ; 34(8): 579-88, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23900932

RESUMO

Despite the experimental evidence of significant biological effects of extremely low frequency (ELF) magnetic fields (MFs), the underlying mechanisms are still unclear. Among the few mechanisms proposed, of particular interest is the so called "ion parametric resonance (IPR)" hypothesis, frequently referred to as theoretical support for medical applications. We studied the effect of different combinations of static (DC) and alternating (AC) ELF MFs tuned on resonance conditions for potassium (K(+)) on TEA-sensitive voltage-dependent outward K(+) currents in the human neuroblastoma BE(2)C cell line. Currents through the cell membrane were measured by whole-cell patch clamp before, during, and after exposure to MF. No significant changes in K(+) current density were found. This study does not confirm the IPR hypothesis at the level of TEA-sensitive voltage-dependent outward K(+) currents in our experimental conditions. However, this is not a direct disprove of the hypothesis, which should be investigated on other ion channels and at single channel levels also.


Assuntos
Fenômenos Eletrofisiológicos/efeitos dos fármacos , Campos Magnéticos , Neuroblastoma/patologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Tetraetilamônio/farmacologia , Linhagem Celular Tumoral , Humanos
12.
Mech Ageing Dev ; 131(11-12): 674-81, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20858515

RESUMO

Aging is a complex process resulting from, among other, dynamic non-linear interactions between genetics and environment. Centenarians are the best example of successful aging in humans, as they escaped from, or largely postponed, major age-related diseases. Ionic fluxes changes play a key role in several patho-physiological cellular processes, but their relation to human aging is largely unexplored. In the present study we have compared patch-clamp potassium (K(+)) current recordings from dermal fibroblasts (DF) obtained from young, elderly and centenarian donors. We found that in DF from elderly donors, but not from centenarians, K(+) current amplitude is significantly smaller with respect to DF from young donors. Moreover, cell membrane capacitance of DF from elderly donors is smaller with respect to young donors and centenarians. We also observed that the voltage-gated Shaker Kv1.1 channel is expressed in higher percentage of elderly's and centenarian's DF than young's, whereas the large-conductance calcium-activated K(+) (BK(Ca)) channel ß1 subunit is expressed in lower percentage of centenarian's DF than in elderly's and young's. The maintenance of "young" K(+) currents and the peculiar age-related remodeling of K(+) channel subtypes in centenarian's DF is likely associated with successful aging and might provide a predictive marker of longevity.


Assuntos
Envelhecimento/metabolismo , Canais de Potássio Ativados por Cálcio de Condutância Alta/metabolismo , Superfamília Shaker de Canais de Potássio/metabolismo , Pele/metabolismo , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Membrana Celular/metabolismo , Células Cultivadas , Fibroblastos/metabolismo , Humanos , Canal de Potássio Kv1.1/metabolismo , Pele/citologia , Adulto Jovem
13.
Mol Biosyst ; 6(10): 1983-92, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20686723

RESUMO

Human aging is associated with complex alterations that contribute to remodelling of physiological processes and ultimately manifests in loss of tissue/organ function. Peripheral blood T cells do not escape this phenomenon and undergo profound remodelling with aging. Thus, investigating the effects of aging on T cells transcriptomics and identifying the underlying regulatory mechanisms can be of extreme importance to understand the aging process in the Immune System (IS). To this aim, we performed an analysis of gene expression data of T cells collected from peripheral blood of 25 healthy human donors of different age from 25 to more than 95 years, in order to characterize changes that occur throughout the entire adult lifespan. By means of microarray analysis, we observed large groups of genes exhibiting non-monotonic expression patterns over time: such behaviour, that could not be observed in typical "two-group" experiments (e.g. young vs. old people) highlights similarities in gene expression profiles of young and "successfully aged" individuals. Genes whose expression profiles change during lifespan were grouped into three main patterns (eigenmodes) to which different biological functions were significantly associated. The analysis of KEGG pathways to which these genes belong indicated that the biological processes altered in T cell aging are not only those typically associated with immune cells (Jak-STAT signalling, T cell receptor signalling, cytokine-cytokine receptor interactions, etc.) but also some not specific of immune cells, such as long-term depression, PPAR and mTOR signalling, glucose and glutathione metabolism, suggesting that T cell aging may be representative of a more generalised aging phenomenon. Thus, the T cell may represent a useful cellular model to study organismal aging. We further searched for over-represented transcription factor binding sites (TFBSs) in the promoter regions of genes clustered by similarity of their age-related patterns to evidence possible co-regulation. A comparison between over-representation of TFBSs and the time course of the corresponding transcription factor (TF) expression levels revealed that a restricted group of TFs may play a central role in driving aging-specific changes in gene expression of T cells.


Assuntos
Envelhecimento/genética , Perfilação da Expressão Gênica , Linfócitos T/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Fatores de Transcrição/metabolismo
14.
Behav Brain Res ; 167(1): 150-5, 2006 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-16256214

RESUMO

The environment in which alcohol consumption occurs may trigger later relapse in alcohol abusers. In this study, we tested whether an alcohol-associated environment would induce alcohol-seeking behavior. Male rats were trained to lever press for oral alcohol reinforcement in a distinctive context. Responding was then extinguished in a context with different olfactory, visual and tactile properties. Placement of the rats back into the original context in which they self-administered alcohol induced, in the absence of alcohol availability, a significant increase in lever press responding on the alcohol lever as compared to extinction levels of responding. The ability of the alcohol context to support alcohol-seeking behavior was maintained over 3 weeks, with no significant diminution. A second group of rats was trained to lever press for sucrose reinforcement; this group also demonstrated context-dependent reinstatement, although the degree of reinstatement decreased over repeated tests, returning to extinction values after 3 weeks. These findings indicate that contextual conditioning has a long-term impact on ethanol-seeking behavior after ethanol withdrawal. This animal model may be useful to study the neural mechanisms underlying relapse induced by ethanol-associated contexts in humans.


Assuntos
Consumo de Bebidas Alcoólicas/psicologia , Depressores do Sistema Nervoso Central/administração & dosagem , Condicionamento Clássico/efeitos dos fármacos , Etanol/administração & dosagem , Reforço Psicológico , Animais , Comportamento Animal , Condicionamento Clássico/fisiologia , Comportamento Exploratório/efeitos dos fármacos , Extinção Psicológica/efeitos dos fármacos , Masculino , Ratos , Autoadministração , Sacarose/administração & dosagem , Edulcorantes/administração & dosagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...