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1.
Langmuir ; 30(15): 4367-74, 2014 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-24670213

RESUMEN

Bacteria play an important role in the biogeochemical cycling of metals in the environment. Consequently, there is an interest to understand how the bacterial surfaces interact with metals in solution and how this affects the bacterial surface. In this work we have used a surface-sensitive analysis technique, cryogenic X-ray photoelectron spectroscopy (cryo-XPS), to monitor the surface of Bacillus subtilis cells as a function of pH and Zn(2+) content in saline solution. The objective of the study was twofold: (1) to investigate the agreement between two data treatment methods for XPS, as well as investigate to what extent sample pretreatment may influence XPS data of bacterial samples, and (2) to characterize how the surface chemistry of bacterial cells is influenced by different external conditions. (1) It was found that the two data treatment methods gave rise to comparable results. However, identical samples analyzed fast-frozen or dry exhibited larger differences in surface chemistry, indicating that sample pretreatment can to large extents influence the obtained surface composition of bacterial samples. (2) The bacterial cell wall (in fast-frozen samples) undergoes dramatic compositional changes with pH and with Zn(2+) exposure. The compositional changes are interpreted as an adaptive metal resistance response changing the biochemical composition of the bacterial cell wall. These results have implications for how adsorption processes at the surface of bacterial cells are analyzed, understood, modeled, and predicted.


Asunto(s)
Bacillus subtilis/efectos de los fármacos , Bacillus subtilis/metabolismo , Pared Celular/efectos de los fármacos , Pared Celular/metabolismo , Espectroscopía de Fotoelectrones/métodos , Zinc/farmacología , Concentración de Iones de Hidrógeno
2.
J Cell Physiol ; 228(7): 1516-24, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23444126

RESUMEN

Autophagy is the main cellular pathway for degradation of long-lived proteins and organelles and regulates cell fate in response to stress. Beclin 1 is a key regulator of this process. In some settings autophagy and apoptosis seem to be interconnected. Recent reports indicate that fibroblasts in idiopathic pulmonary fibrosis (IPF) acquire resistance to apoptosis. Here, we examined the expression of beclin 1, and of the anti apoptotic protein Bcl-2 in human IPF fibroblasts using immunohistochemistry and molecular biology in bioptic sections, in primary cultures of fibroblasts taken from patients with IPF and in fibroblast cell lines. Expression of beclin 1 in fibroblasts from IPF was down-regulated in comparison with fibroblasts from normal lungs while the anti-apoptotic protein Bcl-2 expression was over-expressed. Treatment of fibroblast cell cultures with cisplatin induced a significant increase in beclin 1 and caspase 3 protein levels but a reduction in Bcl-2 expression. These observations were confirmed by the analysis of acid compartments and transmission electron microscopy. Our results demonstrate a modified expression of the apoptotic beclin 1 Bcl-2 proteins in human IPF fibroblasts suggesting the existence of an autophagy/apoptosis system dysfunction.


Asunto(s)
Proteínas Reguladoras de la Apoptosis/metabolismo , Fibrosis Pulmonar Idiopática/metabolismo , Proteínas de la Membrana/metabolismo , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Autofagia/efectos de los fármacos , Autofagia/fisiología , Beclina-1 , Estudios de Casos y Controles , Línea Celular , Células Cultivadas , Cisplatino/farmacología , Femenino , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Fibroblastos/patología , Humanos , Fibrosis Pulmonar Idiopática/patología , Masculino , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo
3.
Vaccine ; 41(25): 3683-3687, 2023 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-37198020

RESUMEN

Parental hesitancy poses a serious threat to the success of the COVID-19 childhood vaccination campaign. We investigate whether adults' opinions on childhood vaccination can be influenced via two survey experiments in Italy (n = 3,633 participants) and the UK (n = 3,314 participants). Respondents were randomly assigned to: a "risk treatment" that highlighted the potential risks of COVID-19 to a child, a "herd immunity treatment" that emphasized the community benefits of pediatric vaccination, or a control message. Participants' probability of supporting COVID-19 childhood vaccination was then assessed on a 0-100 scale. We find that the "risk treatment" reduced the proportion of Italian parents strongly against vaccination by up to 29.6 %, while increasing the proportion of neutral parents by up to 45.0 %. The "herd immunity treatment", instead, was only effective among non-parents, resulting in a lower proportion of individuals against pediatric vaccination and a higher proportion of individuals in favor (both shifted by around 20 %).


Asunto(s)
COVID-19 , Adulto , Niño , Humanos , COVID-19/prevención & control , Inmunidad Colectiva , Programas de Inmunización , Italia/epidemiología , Vacunación
4.
Histochem Cell Biol ; 138(2): 251-69, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22481617

RESUMEN

The keratinocyte growth factor (KGF/FGF7), produced by stromal cells, is a key paracrine mediator of epithelial proliferation, differentiation and migration. Expression of the growth factor is increased in wound healing and in hyperproliferative epithelial diseases, as a consequence of the activation of dermal fibroblasts by the inflammatory microenvironment. The middle ear cholesteatoma, an aural epidermal pathology characterized by keratinocyte hyperproliferation and chronic inflammation, may represent a model condition to study the epithelial-mesenchymal interactions. To develop an in vitro model for this disease, we isolated and characterized human primary cultures of fibroblasts associated with the cholesteatoma lesion, analyzing their secretory behaviour and degree of differentiation or activation. Compared to the perilesional or control normal fibroblasts, all cultures derived from cholesteatoma tissues were less proliferating and more differentiated and their highly variable activated phenotype correlated with the secretion of KGF as well as of metalloproteases 2 and 9. Culture supernatants collected from the cholesteatoma-associated fibroblasts were able to increase the proliferation and differentiation of human keratinocytes assessed by the expression of Ki67 and keratin-1 markers. The single crucial contribution of the KGF released by fibroblasts on the keratinocyte biological response was shown by the specific, although partial, block induced by inhibiting the KGF receptor or by immunoneutralizing the growth factor. Altogether, these results suggest that the activation of the stromal fibroblasts present in the pathological tissue, and the consequent increased secretion of KGF, play a crucial role in the deregulation of the epidermal proliferation and differentiation.


Asunto(s)
Diferenciación Celular , Colesteatoma/metabolismo , Células Epiteliales/metabolismo , Factor 7 de Crecimiento de Fibroblastos/metabolismo , Fibroblastos/metabolismo , Adolescente , Adulto , Anciano , Células Cultivadas , Colesteatoma/patología , Colesteatoma del Oído Medio/metabolismo , Colesteatoma del Oído Medio/patología , Femenino , Humanos , Queratina-1/metabolismo , Masculino , Persona de Mediana Edad , Fenotipo
5.
FASEB J ; 25(1): 170-81, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20844240

RESUMEN

Membrane and actin cytoskeleton dynamics during phagocytosis can be triggered and amplified by the signal transduction of receptor tyrosine kinases. The epidermal keratinocytes appear to use the phagocytic mechanism of uptake to ingest melanosomes released by the melanocytes and play a pivotal role in the transfer process. We have previously demonstrated that the keratinocyte growth factor KGF/FGF7 promotes the melanosome uptake through activation of its receptor tyrosine kinase FGFR2b/KGFR. The aim of the present study was to investigate the contribution of KGFR expression, activation, and signaling in regulating the phagocytic process and the melanosome transfer. Phagocytosis was analyzed in vitro using fluorescent latex beads on human keratinocytes induced to differentiate. Melanosome transfer was investigated in keratinocyte-melanocyte cocultures. KGFR depletion by small interfering RNA microinjection and overexpression by transfection of wild type or defective mutant KGFR were performed to demonstrate the direct effect of the receptor on phagocytosis and melanosome transfer. Colocalization of the phagocytosed beads with the internalized receptors in phagolysosomes was analyzed by optical sectioning and 3-dimensional reconstruction. KGFR ligands triggered phagocytosis and melanosome transfer in differentiated keratinocytes, and receptor kinase activity and signaling were required for these effects, suggesting that FGFR2b/KGFR expression/activity and PLCγ signaling pathway play crucial roles in phagocytosis.


Asunto(s)
Queratinocitos/metabolismo , Melanosomas/metabolismo , Fagocitosis/fisiología , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/metabolismo , Transducción de Señal/fisiología , Western Blotting , Línea Celular , Línea Celular Tumoral , Técnicas de Cocultivo , Factor 10 de Crecimiento de Fibroblastos/metabolismo , Factor 10 de Crecimiento de Fibroblastos/farmacología , Factor 7 de Crecimiento de Fibroblastos/metabolismo , Factor 7 de Crecimiento de Fibroblastos/farmacología , Técnica del Anticuerpo Fluorescente , Humanos , Queratinocitos/citología , Queratinocitos/efectos de los fármacos , Microesferas , Mutación , Fagocitosis/efectos de los fármacos , Fosfolipasa C gamma/metabolismo , Unión Proteica , Interferencia de ARN , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/genética
6.
Environ Sci Technol ; 46(6): 3574-9, 2012 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-22352351

RESUMEN

In order to assess the adsorption properties of hydrogen gas and reactivity of adsorbed hydrogen, we measured H(2)(g) adsorption on Na synthetic montmorillonite-type clays and Callovo-Oxfordian (COx) clayrock using gas chromatography. Synthetic montmorillonites with increasing structural Fe(III) substitution (0 wt %, 3.2 wt %, and 6.4 wt % Fe) were used. Fe in the synthetic montmorillonites is principally present as structural Fe(III) ions. We studied the concomitant reduction of structural Fe(III) in the clays using (57)Fe Mössbauer spectrometry. The COx, which mainly contains smectite/illite and calcite minerals, is also studied together with the pure clay fraction of this clayrock. Experiments were performed with dry clay samples which were reacted with hydrogen gas at 90 and 120 °C for 30 to 45 days at a hydrogen partial pressure close to 0.45 bar. Results indicate that up to 0.11 wt % of hydrogen is adsorbed on the clays at 90 °C under 0.45 bar of relative pressure. (57)Fe Mössbauer spectrometry shows that up to 6% of the total structural Fe(III) initially present in these synthetic clays is reduced upon adsorption of hydrogen gas. No reduction is observed with the COx sample in the present experimental conditions.


Asunto(s)
Silicatos de Aluminio/química , Bentonita/química , Hidrógeno/química , Adsorción , Arcilla , Calor , Hierro/química , Oxidación-Reducción , Residuos Radiactivos , Espectroscopía de Mossbauer , Acero Inoxidable
7.
Homeopathy ; 100(4): 212-9, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21962195

RESUMEN

OBJECTIVE: To test a methodology to evaluate, at population level, the effectiveness of homeopathic treatment through standard objective public health indicators. METHODS AND SETTINGS: Indicators of hospitalization and drug use were obtained from the Health Statistical Documentation System of Tuscany for two homeopathic centers in the Local Health Authority of Pisa, Italy. We compared homeopathic users with the general population in the same area and by comparing patients before and after homeopathic treatment. RESULTS: The homeopathic patients used less drugs than the reference population, this effect was more evident for patients with repeated homeopathic consultations. A significant decrease in drug use was found on comparing the same patients before and after homeopathic treatment. Hospitalization indicators tended to favour patients who had received homeopathic treatment but were not always statistically significant. CONCLUSIONS: This paper demonstrates a new methodological approach to assess the effectiveness of a therapeutic modality, without ad-hoc clinical trials. This methodology can be used by public health institutions in which non-conventional medicines are integrated into the public health care system.


Asunto(s)
Homeopatía/estadística & datos numéricos , Homeopatía/normas , Satisfacción del Paciente , Salud Pública/tendencias , Hospitalización , Humanos , Italia , Reproducibilidad de los Resultados , Estadística como Asunto
8.
Sci Rep ; 11(1): 11895, 2021 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-34088936

RESUMEN

Synchrotron X-ray tomography enables the examination of the internal structure of materials at submicron spatial resolution and subsecond temporal resolution. Unavoidable experimental constraints can impose dose and time limits on the measurements, introducing noise in the reconstructed images. Convolutional neural networks (CNNs) have emerged as a powerful tool to remove noise from reconstructed images. However, their training typically requires collecting a dataset of paired noisy and high-quality measurements, which is a major obstacle to their use in practice. To circumvent this problem, methods for CNN-based denoising have recently been proposed that require no separate training data beyond the already available noisy reconstructions. Among these, the Noise2Inverse method is specifically designed for tomography and related inverse problems. To date, applications of Noise2Inverse have only taken into account 2D spatial information. In this paper, we expand the application of Noise2Inverse in space, time, and spectrum-like domains. This development enhances applications to static and dynamic micro-tomography as well as X-ray diffraction tomography. Results on real-world datasets establish that Noise2Inverse is capable of accurate denoising and enables a substantial reduction in acquisition time while maintaining image quality.

9.
Exp Cell Res ; 315(13): 2181-91, 2009 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-19362549

RESUMEN

The keratinocyte growth factor receptor or fibroblast growth factor receptor 2b (KGFR/FGFR2b) is activated by the specific interaction with the keratinocyte growth factor (KGF/FGF7), which targets the receptor to the degradative pathway, and the fibroblast growth factor 10 (FGF10/KGF2), which drives the receptor to the juxtanuclear recycling route. Hrs plays a key role in the regulation of the endocytic degradative transport of ubiquitinated receptor tyrosine kinases, but the direct involvement of this protein in the regulation of FGFR endocytosis has not been investigated yet. We investigated here the possible role of Hrs in the alternative endocytic pathways of KGFR. Quantitative immunofluorescence microscopy and biochemical analysis showed that both overexpression and siRNA interference of Hrs inhibit the KGF-triggered KGFR degradation, blocking receptor transport to lysosomes and causing its rapid reappearance at the plasma membrane. In contrast, the FGF10-induced KGFR targeting to the recycling compartment is not affected by Hrs overexpression or depletion. Coimmunoprecipitation approaches indicated that Hrs is recruited to KGFR only after KGF treatment, although it is not tyrosine phosphorylated by the ligand. In conclusion, Hrs regulates the KGFR degradative pathway, but not its juxtanuclear recycling transport. In addition, the results suggest that Hrs recruitment to the receptor, but not its ligand-induced phosphorylation, could be required for its function.


Asunto(s)
Endocitosis/fisiología , Fosfoproteínas/metabolismo , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/metabolismo , Animales , Complejos de Clasificación Endosomal Requeridos para el Transporte , Receptores ErbB/genética , Receptores ErbB/metabolismo , Factor 10 de Crecimiento de Fibroblastos/farmacología , Factor 7 de Crecimiento de Fibroblastos/farmacología , Células HeLa/efectos de los fármacos , Humanos , Lisosomas/metabolismo , Ratones , Células 3T3 NIH/efectos de los fármacos , Fosfoproteínas/genética , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/genética , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo
10.
J Nucl Med ; 50(2): 198-204, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19164220

RESUMEN

UNLABELLED: 11C-Pittsburgh Compound B (11C-PiB) PET has demonstrated significantly higher PiB retention in the gray matter of Alzheimer disease (AD) patients than in healthy controls (HCs). PiB is similarly retained within the white matter of HC and AD brains. Although the specificity of PiB for Abeta plaques in gray matter has been well described, the nature of PiB binding to white matter remains unclear. In this study, we characterized the binding of PiB to human white matter homogenates. METHODS: In vitro binding studies were conducted using 3H-PiB (0.1-500 nM) and white matter brain homogenates (100 microg) from 3 AD patients and 3 HCs. Nonspecific binding was determined using PiB (1 microM). White matter from the same patients was also analyzed by immunofluorescence/immunohistochemistry (IF/IHC) microscopy and Western blotting for Abeta expression. White matter kinetics were also characterized in vivo through 11C-PiB PET studies in 27 HCs and 34 patients with dementia. IF/IHC experiments were conducted on 1 postmortem patient with dementia, to compare with the 11C-PiB distribution volume ratio data acquired 23 mo earlier. RESULTS: In vitro saturation studies indicated that 3H-PiB binds nonspecifically to white matter brain homogenates. PiB fluorescence staining of AD and HC brain sections was consistent with absence of Abeta in IHC staining. Higher gray matter-to-white matter ratios were observed in IHC images than in 11C-PiB PET images. CONCLUSION: These studies suggest that PiB binding to white matter is mainly nonsaturable and nonspecific and that PiB retention in the 11C-PiB PET studies is largely attributable to slower PiB white matter kinetics.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico por imagen , Benzotiazoles , Encéfalo/diagnóstico por imagen , Radioisótopos de Carbono , Enfermedad por Cuerpos de Lewy/diagnóstico por imagen , Radiofármacos , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Compuestos de Anilina , Benzotiazoles/farmacocinética , Encéfalo/metabolismo , Radioisótopos de Carbono/farmacocinética , Estudios de Casos y Controles , Femenino , Humanos , Inmunohistoquímica , Técnicas In Vitro , Enfermedad por Cuerpos de Lewy/metabolismo , Masculino , Persona de Mediana Edad , Cintigrafía , Radiofármacos/farmacocinética , Tiazoles
11.
J Environ Monit ; 11(4): 756-60, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19557226

RESUMEN

The community of running water macroinvertebrates has proved to be one of key subjects for fluvial ecology and bioindication studies, thanks both to the different trophic roles within the range of taxa and to the ease with which they may be collected and identified. However, the complex nature of this community creates problems concerning the complete identification of the full range of taxa, even when restricting the taxonomic classification to families and genera. Even so, the need to use the community for the implementation of indexes of Ecological Status of freshwaters and for the detection of reference conditions, necessarily means a deeper knowledge of this structure. Hence, a standard methodology of the capture effort is required to identify not only the ecological quality but also a reference community for each selected fluvial typology and for each section examined. Starting from the processing of data collected during intercalibration exercises of the IBE method, the authors analyse the results underlining the share given by the size of the sample collected (catchment effort), and by the distribution models of different taxa within the community, in order to give a contribution to the evaluation of the reliability level of standard samples. The results confirm the models already described in previous publications and lead us to accept the presence of marginal degrees of uncertainty in standard samples.


Asunto(s)
Biodiversidad , Invertebrados/fisiología , Movimientos del Agua , Animales , Ecología/métodos , Cadena Alimentaria , Invertebrados/clasificación , Italia , Ríos/química
12.
J Neurosci ; 27(39): 10365-71, 2007 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-17898208

RESUMEN

Dementia with Lewy bodies (DLB) is pathologically characterized by the presence of alpha-synuclein-containing Lewy bodies within the neocortical, limbic, and paralimbic regions. Like Alzheimer's disease (AD), Abeta plaques are also present in most DLB cases. The contribution of Abeta to the development of DLB is unclear. [11C]-Pittsburgh compound B ([11C]-PIB) is a thioflavin-T derivative that has allowed in vivo Abeta burden to be quantified using positron emission tomography (PET). [11C]-PIB PET studies have shown similar high cortical [11C]-PIB binding in AD and DLB subjects. To establish the potential binding of PIB to alpha-synuclein in DLB patients, we characterized the in vitro binding of PIB to recombinant human alpha-synuclein and DLB brain homogenates. Analysis of the in vitro binding studies indicated that [3H]-PIB binds to alpha-synuclein fibrils but with lower affinity than that demonstrated/reported for Abeta(1-42) fibrils. Furthermore, [3H]-PIB was observed to bind to Abeta plaque-containing DLB brain homogenates but failed to bind to DLB homogenates that were Abeta plaque-free ("pure DLB"). Positive PIB fluorescence staining of DLB brain sections colocalized with immunoreactive Abeta plaques but failed to stain Lewy bodies. Moreover, image quantification analysis suggested that given the small size and low density of Lewy bodies within the brains of DLB subjects, any contribution of Lewy bodies to the [11C]-PIB PET signal would be negligible. These studies indicate that PIB retention observed within the cortical gray matter regions of DLB subjects in [11C]-PIB PET studies is largely attributable to PIB binding to Abeta plaques and not Lewy bodies.


Asunto(s)
Péptidos beta-Amiloides/metabolismo , Compuestos de Anilina/metabolismo , Cuerpos de Lewy/fisiología , Enfermedad por Cuerpos de Lewy/metabolismo , Tiazoles/metabolismo , alfa-Sinucleína/metabolismo , Sitios de Unión , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/fisiopatología , Humanos , Técnicas In Vitro , Enfermedad por Cuerpos de Lewy/diagnóstico por imagen , Enfermedad por Cuerpos de Lewy/fisiopatología , Tomografía de Emisión de Positrones
13.
Anal Cell Pathol (Amst) ; 2018: 3506874, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29682444

RESUMEN

BACKGROUND: Non-small cell lung cancer (NSCLC) is the most common cause of cancer-related mortality; nevertheless, there are few data regarding detection of circulating tumor cells (CTCs) in NSCLC, compared to other kinds of cancers in which their prognostic roles have already been defined. This difference is likely due to detection methods based on the epithelial marker expression which ignore CTCs undergoing epithelial-mesenchymal transition (CTCsEMT). METHODS: After optimization of the test with spiking experiments of A549 cells undergoing TGF-ß1-induced EMT (A549EMT), the CTCsEMT were enriched by immunomagnetic depletion of leukocytes and then characterized by a RT-PCR assay based on the retrieval of epithelial and EMT-related genes. Blood samples from ten metastatic NSCLC patients before starting treatment and during chemotherapy were used to test this approach by longitudinal monitoring. Ten age- and sex-matched healthy subjects were also enrolled as controls. RESULTS: Recovery experiments of spiked A549EMT cells showed that the RT-PCR assay is a reliable method for detection of CTCsEMT. CTCsEMT were detected in three patients at baseline and in six patients after four cycles of cysplatin-based chemotherapy. Longitudinal monitoring of three patients showed that the CTCsEMT detection is related to poor therapeutic response. CONCLUSIONS: The RT-PCR-based approach for the evaluation of CTCsEMT phenotype could be a promising and inexpensive tool to predict the prognosis and the therapeutic response in NSCLC patients.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Transición Epitelial-Mesenquimal , Neoplasias Pulmonares/patología , Células Neoplásicas Circulantes/patología , Pautas de la Práctica en Medicina , Células A549 , Anciano , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/terapia , Recuento de Células , Transición Epitelial-Mesenquimal/efectos de los fármacos , Femenino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/terapia , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Células Neoplásicas Circulantes/efectos de los fármacos , Células Neoplásicas Circulantes/metabolismo , Fenotipo , Pronóstico , Reacción en Cadena en Tiempo Real de la Polimerasa , Reproducibilidad de los Resultados , Factor de Crecimiento Transformador beta1/farmacología , Resultado del Tratamiento
14.
FASEB J ; 20(2): 395-7, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16354720

RESUMEN

UVB exposure of epidermal cells is known to trigger early and late molecular pathways dependent on receptor tyrosine kinases and reactive oxygen species (ROS). We have recently reported that UVB irradiation induces tyrosine phosphorylation, kinase activation, and internalization of the receptor for the keratinocyte growth factor (KGFR), a paracrine mediator of epithelial growth, differentiation, and survival. Here we analyzed in more detail the UVB-induced endocytic pathway of KGFR and the role of KGFR activation and internalization in regulating UVB-promoted apoptosis and cell cycle arrest. Immunogold electron microscopy and confocal analysis revealed that the UVB-induced endocytosis of KGFR occurs through clathrin-coated pits and that the internalized receptors are sorted to the degradative route and reach the lysosomal compartment with a timing similar to that induced by their ligand KGF. Treatment with the anti-oxidant N-acetylcysteine inhibited KGFR endocytosis, suggesting that the receptor internalization is mediated by the intracellular production of ROS. The ligand-independent KGFR endocytic pathway induced by UVB requires receptor kinase activity and tyrosine phosphorylation and involves transient receptor ubiquitination. Inhibition of KGFR activity reduces both the KGF-mediated proliferative response and the UVB-promoted apoptotic cell death, indicating a different effect of ligand-induced and UVB-induced KGFR triggering. In addition, receptor internalization leads to protection from apoptosis caused by UVB exposure. Finally, we compared directly the behavior of KGFR with that of the epidermal growth factor receptor (EGFR) upon UVB exposure. Surprisingly, biochemical and immunofluorescence analysis showed that EGFR, differently from KGFR, does not undergo UVB-induced tyrosine phosphorylation and internalization. Taken together, our results suggest a differential role of KGFR and EGFR in the response of epidermal cells to UVB possibly because KGFR endocytosis could be crucial for attenuation of survival signals in the suprabasal layers of human skin.


Asunto(s)
Endocitosis/fisiología , Endocitosis/efectos de la radiación , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/metabolismo , Rayos Ultravioleta , Animales , Apoptosis , Ciclo Celular , Clatrina/metabolismo , Receptores ErbB/metabolismo , Regulación de la Expresión Génica , Humanos , Ligandos , Ratones , Células 3T3 NIH , Fosforilación , Fosfotirosina/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/genética
15.
PLoS One ; 11(1): e0146365, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26812644

RESUMEN

The ability of some bacterial pathogens to activate Epithelial-Mesenchymal Transition normally is a consequence of the persistence of a local chronic inflammatory response or depends on a direct interaction of the pathogens with the host epithelial cells. In this study we monitored the abilities of the K. pneumoniae to activate the expression of genes related to EMT-like processes and the occurrence of phenotypic changes in airway epithelial cells during the early steps of cell infection. We describe changes in the production of intracellular reactive oxygen species and increased HIF-1α mRNA expression in cells exposed to K. pneumoniae infection. We also describe the upregulation of a set of transcription factors implicated in the EMT processes, such as Twist, Snail and ZEB, indicating that the morphological changes of epithelial cells already appreciable after few hours from the K. pneumoniae infection are tightly regulated by the activation of transcriptional pathways, driving epithelial cells to EMT. These effects appear to be effectively counteracted by resveratrol, an antioxidant that is able to exert a sustained scavenging of the intracellular ROS. This is the first report indicating that strains of K. pneumoniae may promote EMT-like programs through direct interaction with epithelial cells without the involvement of inflammatory cells.


Asunto(s)
Transición Epitelial-Mesenquimal , Klebsiella pneumoniae/fisiología , Línea Celular Tumoral , Supervivencia Celular , Células Epiteliales/citología , Células Epiteliales/metabolismo , Células Epiteliales/microbiología , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Klebsiella pneumoniae/aislamiento & purificación , Microscopía Fluorescente , Fenotipo , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Factores de Transcripción de la Familia Snail , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteína 1 Relacionada con Twist/genética , Proteína 1 Relacionada con Twist/metabolismo , Regulación hacia Arriba , Homeobox 1 de Unión a la E-Box con Dedos de Zinc
16.
Oncotarget ; 7(6): 6410-23, 2016 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-26843618

RESUMEN

Extracorporeal shock wave therapy (ESWT) is a non-invasive and innovative technology for the management of specific tendinopathies. In order to elucidate the ESWT-mediated clinical benefits, human Tendon-derived Stem/Progenitor cells (hTSPCs) explanted from 5 healthy semitendinosus (ST) and 5 ruptured Achilles (AT) tendons were established. While hTSPCs from the two groups showed similar proliferation rates and stem cell surface marker profiles, we found that the clonogenic potential was maintained only in cells derived from healthy donors. Interestingly, ESWT significantly accelerated hTSPCs differentiation, suggesting that the clinical benefits of ESWT may be ascribed to increased efficiency of tendon repair after injury.


Asunto(s)
Diferenciación Celular/fisiología , Proliferación Celular/fisiología , Ondas de Choque de Alta Energía , Células Madre/citología , Traumatismos de los Tendones/patología , Tendones/citología , Adipogénesis/efectos de la radiación , Diferenciación Celular/efectos de la radiación , Proliferación Celular/efectos de la radiación , Células Cultivadas , Técnica del Anticuerpo Fluorescente , Humanos , Técnicas In Vitro , Osteogénesis/efectos de la radiación , Células Madre/fisiología , Células Madre/efectos de la radiación , Traumatismos de los Tendones/radioterapia , Tendones/fisiología , Tendones/efectos de la radiación
17.
Future Microbiol ; 10(5): 743-61, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26000649

RESUMEN

BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae strains (KPC-Kp) are emerging worldwide causing different nosocomial infections including those of the urinary tract, lung or skin wounds. For these strains, the antibiotic treatment is limited to only few choices including colistin, whose continuous use led to the emergence of carbapenem-resistant KPC-Kp strains resistant also to this treatment (KPC-Kp Col-R). AIM: Very little is known about the capacity of the different strains of KPC-Kp to invade the epithelial cells in vitro. To verify if the acquisition of carbapenem-resistant and the colistin-resistant phenotypes are correlated with a different ability to infect a series of epithelial cell lines of various tissutal origin and with a different capacity to induce cellular death. MATERIALS & METHODS: We used Klebsiella pneumoniae (KP), KPC-Kp and KPC-Kp Col-R strains, isolated from different patients carrying various tissue-specific infections, to infect a series of epithelial cell lines of different tissutal origin. The invasive capacity of the strains and the extent and characteristics of the cell damage and death induced by the bacteria were evaluated and compared. CONCLUSION: Our results show that both KPC-Kp and KPC-Kp Col-R display a greater ability to infect the epithelial cells, with respect to KP, and that the bacterial cell invasion results in a nonprogrammed cell death.


Asunto(s)
Muerte Celular , Endocitosis , Células Epiteliales/microbiología , Células Epiteliales/fisiología , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/fisiología , Resistencia betalactámica , Línea Celular , Humanos , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/aislamiento & purificación
18.
FEBS Lett ; 553(3): 262-70, 2003 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-14572635

RESUMEN

Keratinocyte growth factor receptor (KGFR) is a receptor tyrosine kinase expressed on epithelial cells. Following ligand binding, KGFR is rapidly activated and internalized by clathrin-mediated endocytosis. Among the possible receptor substrates which could be involved in the regulation of KGFR endocytosis and down-modulation, we analyzed here the eps15 protein in view of the proposed general role of eps15 in regulating clathrin-mediated endocytosis as well as that of eps15 tyrosine phosphorylation in the control of regulated endocytosis. Immunoprecipitation and Western blot analysis showed that activated KGFR was not able to phosphorylate eps15, suggesting that eps15 is not a receptor substrate. Double immunofluorescence and confocal microscopy revealed that activated KGFR, differently from epidermal growth factor receptor (EGFR), did not induce recruitment of eps15 to the cell plasma membrane. Microinjection of a monoclonal antibody directed against the C-terminal DPF domain which contains the AP2 binding region of eps15 led to inhibition of both pathways of receptor-mediated endocytosis, the EGFR ligand-induced endocytosis and the transferrin constitutive endocytosis, but did not appear to block the KGFR ligand-induced internalization. Taken together our results indicate that the clathrin-mediated uptake of KGFR is not mediated by eps15.


Asunto(s)
Proteínas de Unión al Calcio/metabolismo , Clatrina/metabolismo , Endocitosis/fisiología , Fosfoproteínas/metabolismo , Receptores de Factores de Crecimiento de Fibroblastos/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/farmacología , Proteínas de Unión al Calcio/inmunología , Membrana Celular/fisiología , Membrana Celular/ultraestructura , Receptores ErbB/genética , Receptores ErbB/metabolismo , Humanos , Péptidos y Proteínas de Señalización Intracelular , Ligandos , Ratones , Microinyecciones , Microscopía Confocal , Células 3T3 NIH , Fosfoproteínas/inmunología , Fosforilación , Pruebas de Precipitina , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos , Receptores de Factores de Crecimiento de Fibroblastos/genética , Transfección , Tirosina/metabolismo
19.
J Gastrointestin Liver Dis ; 23(3): 279-84, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25267956

RESUMEN

BACKGROUND AND AIMS: Data on the potential of circulating tumor cells (CTC) count in predicting overall survival (OS) in patients with colorectal cancer are timely and worthy of interest. This study aimed to evaluate the prognostic role of CTC count in both localized and metastatic colorectal cancer patients. METHODS: Consecutive patients with histological diagnosis of colorectal cancer were enrolled. CTC count was performed, by using a quantitative immunofluorescence method, at baseline (T0) and 1 month following start of chemotherapy (T1). A CTC count <2 was considered negative, whilst a CTC level >/= 2 was positive. Overall survival was calculated accordingly. RESULTS: A total of 75 colorectal cancer patients were enrolled, including 54 stages I-III and 21 stage IV patients. Overall, 21 (28%) patients had a positive CTC count at baseline, and it was significantly associated with a worse prognosis as compared to a negative status (OS: 36.2 vs. 61.6 months; P = 0.002). CTC count remained positive after chemotherapy in 22.4% of the patients and it was an independent prognostic factor of OS (P = 0.03; Hazard Ratio: 3.55; 95% CI: 1.1-11.5). CONCLUSIONS: This study found that the presence of CTCs is associated with a reduced survival in colorectal cancer patients. Further studies aimed at testing such a predictive value in early stage colorectal cancer are awaited.


Asunto(s)
Neoplasias Colorrectales/patología , Células Neoplásicas Circulantes/patología , Adulto , Anciano , Anciano de 80 o más Años , Recuento de Células , Neoplasias Colorrectales/sangre , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/terapia , Supervivencia sin Enfermedad , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Estadificación de Neoplasias , Valor Predictivo de las Pruebas , Modelos de Riesgos Proporcionales , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
20.
PLoS One ; 7(11): e49759, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23189160

RESUMEN

In vitro models of human tenocytes derived from healthy as well as from ruptured tendons were established, characterized and used at very early passage (P1) to evaluate the effects of Extracorporeal Shock Wave Treatment (ESWT). The molecular analysis of traditional tenocytic markers, including Scleraxis (Scx), Tenomodulin (Tnm), Tenascin-C (Tn-C) and Type I and III Collagens (Col I and Col III), permitted us to detect in our samples the simultaneous expression of all these genes and allowed us to compare their levels of expression in relationship to the source of the cells and treatments. In untreated conditions, higher molecular levels of Scx and Col I in tenocytes from pathological compared to healthy samples have been detected, suggesting--in the cells from injured tendon--the natural trigger of an early differentiation and repairing program, which depends by Scx and requires an increase in collagen expression. When ESWT (at the dose of 0.14 mJ/mm(2)) was applied to cultured tenocytes explanted from injured source, Scx and Col I were significantly diminished compared to healthy counterpart, indicating that such natural trigger maybe delayed by the treatment, in order to promote cellular repair. Herein, we show for the first time that ESWT enhances in vitro functional activities of ruptured tendon-derived tenocytes, such as proliferation and migration, which could probably contributes to tendon healing in vivo.


Asunto(s)
Traumatismos de los Tendones/metabolismo , Tendones/citología , Tendones/metabolismo , Adolescente , Adulto , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Células Cultivadas , Colágeno/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cultivo Primario de Células , Tenascina/metabolismo , Traumatismos de los Tendones/terapia , Adulto Joven
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