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1.
Sci Rep ; 14(1): 13052, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38844814

RESUMEN

European University alliances, formally introduced in 2019, are rapidly expanding, as more than 400 million euros have been dedicated in 2023 by the European Commission to foster international collaborations to promote new forms of development within and beyond university communities. By undertaking interventionist research on UNITA - Universitas Montium, one of the largest European alliances, representing 160.000 students, this paper aims to illustrate how a university alliance is tasked with developing an internal assessment methodology to account for the societal benefits created by the project for the academic and civil communities. The elaboration of the assessment tool to assess the contribution to higher education and societal sustainable communities has brought researchers to discover etic and emic implications, revealing the existence of an accountability layer in which the international alliance directly engages with rural and mountain communities in marginalized areas. This research marks a significant advancement in the field of higher education sustainability, providing both a novel analytical perspective on the benefits of university alliances for the development of local sustainable communities and a methodological tool for their assessment.

2.
Front Cell Infect Microbiol ; 14: 1367359, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38660488

RESUMEN

Cryptosporidium parvum is a common cause of a zoonotic disease and a main cause of diarrhea in newborns. Effective drugs or vaccines are still lacking. Oocyst is the infective form of the parasite; after its ingestion, the oocyst excysts and releases four sporozoites into the host intestine that rapidly attack the enterocytes. The membrane protein CpRom1 is a large rhomboid protease that is expressed by sporozoites and recognized as antigen by the host immune system. In this study, we observed the release of CpRom1 with extracellular vesicles (EVs) that was not previously described. To investigate this phenomenon, we isolated and resolved EVs from the excystation medium by differential ultracentrifugation. Fluorescence flow cytometry and transmission electron microscopy (TEM) experiments identified two types of sporozoite-derived vesicles: large extracellular vesicles (LEVs) and small extracellular vesicles (SEVs). Nanoparticle tracking analysis (NTA) revealed mode diameter of 181 nm for LEVs and 105 nm for SEVs, respectively. Immunodetection experiments proved the presence of CpRom1 and the Golgi protein CpGRASP in LEVs, while immune-electron microscopy trials demonstrated the localization of CpRom1 on the LEVs surface. TEM and scanning electron microscopy (SEM) showed that LEVs were generated by means of the budding of the outer membrane of sporozoites; conversely, the origin of SEVs remained uncertain. Distinct protein compositions were observed between LEVs and SEVs as evidenced by their corresponding electrophoretic profiles. Indeed, a dedicated proteomic analysis identified 5 and 16 proteins unique for LEVs and SEVs, respectively. Overall, 60 proteins were identified in the proteome of both types of vesicles and most of these proteins (48 in number) were already identified in the molecular cargo of extracellular vesicles from other organisms. Noteworthy, we identified 12 proteins unique to Cryptosporidium spp. and this last group included the immunodominant parasite antigen glycoprotein GP60, which is one of the most abundant proteins in both LEVs and SEVs.


Asunto(s)
Cryptosporidium parvum , Vesículas Extracelulares , Proteínas Protozoarias , Esporozoítos , Vesículas Extracelulares/metabolismo , Cryptosporidium parvum/metabolismo , Esporozoítos/metabolismo , Proteínas Protozoarias/metabolismo , Proteínas Protozoarias/análisis , Microscopía Electrónica de Transmisión , Animales , Criptosporidiosis/parasitología , Humanos , Proteoma/análisis , Proteómica , Citometría de Flujo
3.
Health Policy ; 142: 104960, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38377670

RESUMEN

BACKGROUND: Immigration has become a structural phenomenon in Italy, a country reputed as being 'immigrant-friendly'. The increase in the proportion of immigrants has led to increasing efforts to design and implement health policies throughout the country while controlling public spending. METHOD: Being interested in both the cross-sectional and time series dimensions of analysis, we used a PVAR (Panel Vector Autoregression) model, which combines the VAR technique with panel data models, to estimate the impact of regular immigration on health expenditure. FINDINGS: Our results confirm that an increase in the share of regular immigrants in the total population decreases the amount of aggregate public health expenditure. CONCLUSION: Despite the intense activity by Italian governments on social and health integration policies for immigrants, policymakers may focus more on the implementation of national policies at regional and local levels, on their costs and with a specific focus on undocumented immigrants.


Asunto(s)
Emigrantes e Inmigrantes , Gastos en Salud , Humanos , Estudios Transversales , Emigración e Inmigración , Política de Salud , Accesibilidad a los Servicios de Salud
4.
J Extracell Vesicles ; 12(12): e12392, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-38072803

RESUMEN

Exosomes are among the most puzzling vehicles of intercellular communication, but several crucial aspects of their biogenesis remain elusive, primarily due to the difficulty in purifying vesicles with similar sizes and densities. Here we report an effective methodology for labelling small extracellular vesicles (sEV) using Bodipy FL C16, a fluorescent palmitic acid analogue. In this study, we present compelling evidence that the fluorescent sEV population derived from Bodipy C16-labelled cells represents a discrete subpopulation of small exosomes following an intracellular pathway. Rapid cellular uptake and metabolism of Bodipy C16 resulted in the incorporation of fluorescent phospholipids into intracellular organelles specifically excluding the plasma membrane and ultimately becoming part of the exosomal membrane. Importantly, our fluorescence labelling method facilitated accurate quantification and characterization of exosomes, overcoming the limitations of nonspecific dye incorporation into heterogeneous vesicle populations. The characterization of Bodipy-labelled exosomes reveals their enrichment in tetraspanin markers, particularly CD63 and CD81, and in minor proportion CD9. Moreover, we employed nanoFACS sorting and electron microscopy to confirm the exosomal nature of Bodipy-labelled vesicles. This innovative metabolic labelling approach, based on the fate of a fatty acid, offers new avenues for investigating exosome biogenesis and functional properties in various physiological and pathological contexts.


Asunto(s)
Exosomas , Vesículas Extracelulares , Vesículas Extracelulares/metabolismo , Ácido Palmítico/metabolismo , Exosomas/metabolismo , Transporte Biológico
5.
Traffic ; 24(2): 76-94, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36519961

RESUMEN

Caveolin-1 (Cav-1) is a fundamental constituent of caveolae, whose functionality and structure are strictly dependent on cholesterol. In this work the U18666A inhibitor was used to study the role of cholesterol transport in the endosomal degradative-secretory system in a metastatic human melanoma cell line (WM266-4). We found that U18666A induces a shift of Cav-1 from the plasma membrane to the endolysosomal compartment, which is involved, through Multi Vesicular Bodies (MVBs), in the formation and release of small extracellular vesicles (sEVs). Moreover, this inhibitor induces an increase in the production of sEVs with chemical-physical characteristics similar to control sEVs but with a different protein composition (lower expression of Cav-1 and increase of LC3II) and reduced transfer capacity on target cells. Furthermore, we determined that U18666A affects mitochondrial function and also cancer cell aggressive features, such as migration and invasion. Taken together, these results indicate that the blockage of cholesterol transport, determining the internalization of Cav-1, may modify sEVs secretory pathways through an increased fusion between autophagosomes and MVBs to form amphisome, which in turn fuses with the plasma membrane releasing a heterogeneous population of sEVs to maintain homeostasis and ensure correct cellular functionality.


Asunto(s)
Vesículas Extracelulares , Melanoma , Humanos , Caveolina 1/metabolismo , Autofagosomas/metabolismo , Vesículas Extracelulares/metabolismo , Colesterol/metabolismo
6.
Viruses ; 14(1)2021 12 31.
Artículo en Inglés | MEDLINE | ID: mdl-35062278

RESUMEN

Plasmacytoid dendritic cells (pDCs) are a unique dendritic cell subset specialized in type I interferon production, whose role in Human Immunodeficiency Virus (HIV) infection and pathogenesis is complex and not yet well defined. Considering the crucial role of the accessory protein Nef in HIV pathogenicity, possible alterations in intracellular signalling and extracellular vesicle (EV) release induced by exogenous Nef on uninfected pDCs have been investigated. As an experimental model system, a human plasmacytoid dendritic cell line, GEN2.2, stimulated with a myristoylated recombinant NefSF2 protein was employed. In GEN2.2 cells, Nef treatment induced the tyrosine phosphorylation of STAT-1 and STAT-2 and the production of a set of cytokines, chemokines and growth factors including IP-10, MIP-1ß, MCP-1, IL-8, TNF-α and G-CSF. The released factors differed both in type and amount from those released by macrophages treated with the same viral protein. Moreover, Nef treatment slightly reduces the production of small EVs, and the protein was found associated with the small (size < 200 nm) but not the medium/large vesicles (size > 200 nm) collected from GEN2.2 cells. These results add new information on the interactions between this virulence factor and uninfected pDCs, and may provide the basis for further studies on the interactions of Nef protein with primary pDCs.


Asunto(s)
Citocinas/metabolismo , Células Dendríticas/metabolismo , Vesículas Extracelulares/metabolismo , VIH-1/metabolismo , Productos del Gen nef del Virus de la Inmunodeficiencia Humana/metabolismo , Línea Celular , Quimiocinas/metabolismo , Células Dendríticas/virología , Infecciones por VIH/virología , Humanos , Macrófagos/metabolismo , Proteínas Recombinantes , Factor de Transcripción STAT1/metabolismo , Transducción de Señal , Factor de Necrosis Tumoral alfa/metabolismo , Productos del Gen nef del Virus de la Inmunodeficiencia Humana/genética , Productos del Gen nef del Virus de la Inmunodeficiencia Humana/inmunología
7.
Int J Mol Sci ; 21(17)2020 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-32878276

RESUMEN

Immunosuppression at tumor microenvironment (TME) is one of the major obstacles to be overcome for an effective therapeutic intervention against solid tumors. Tumor-associated macrophages (TAMs) comprise a sub-population that plays multiple pro-tumoral roles in tumor development including general immunosuppression, which can be identified in terms of high expression of mannose receptor (MR or CD206). Immunosuppressive TAMs, like other macrophage sub-populations, display functional plasticity that allows them to be re-programmed to inflammatory macrophages. In order to mitigate immunosuppression at the TME, several efforts are ongoing to effectively re-educate pro-tumoral TAMs. Extracellular vesicles (EVs), released by both normal and tumor cells types, are emerging as key mediators of the cell to cell communication and have been shown to have a role in the modulation of immune responses in the TME. Recent studies demonstrated the enrichment of high mannose glycans on the surface of small EVs (sEVs), a subtype of EVs of endosomal origin of 30-150 nm in diameter. This characteristic renders sEVs an ideal tool for the delivery of therapeutic molecules into MR/CD206-expressing TAMs. In this review, we report the most recent literature data highlighting the critical role of TAMs in tumor development, as well as the experimental evidences that has emerged from the biochemical characterization of sEV membranes. In addition, we propose an original way to target immunosuppressive TAMs at the TME by endogenously engineered sEVs for a new therapeutic approach against solid tumors.


Asunto(s)
Vesículas Extracelulares/inmunología , Tolerancia Inmunológica/inmunología , Lectinas Tipo C/metabolismo , Macrófagos/inmunología , Lectinas de Unión a Manosa/metabolismo , Neoplasias/inmunología , Receptores de Superficie Celular/metabolismo , Microambiente Tumoral/inmunología , Animales , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/patología , Humanos , Macrófagos/metabolismo , Macrófagos/patología , Receptor de Manosa , Neoplasias/metabolismo , Neoplasias/patología
9.
Biomolecules ; 9(7)2019 07 17.
Artículo en Inglés | MEDLINE | ID: mdl-31319608

RESUMEN

Cholesterol-enriched functional portions of plasma membranes, such as caveolae and rafts, were isolated from lungs of wild-type (WT) and caveolin-1 knockout (Cav-1 KO) mice within detergent resistant membranes (DRMs). To gain insight into their molecular composition we performed proteomic and lipid analysis on WT and Cav-1 KO-DRMs that showed predicted variations of proteomic profiles and negligible differences in lipid composition, while Langmuir monolayer technique and small and wide-angle X-ray scattering (SAXS-WAXS) were here originally introduced to study DRMs biophysical association state. Langmuir analysis of Cav-1 containing DRMs displayed an isotherm with a clear-cut feature, suggesting the coexistence of the liquid-ordered (Lo) phase typical of the raft structure, namely "cholesterol-rich Lo phase," with a phase fully missing in Cav-1 KO that we named "caveolin-induced Lo phase." Furthermore, while the sole lipid component of both WT and KO-DRMs showed qualitatively similar isotherm configuration, the reinsertion of recombinant Cav-1 into WT-DRMs lipids restored the WT-DRM pattern. X-ray diffraction results confirmed that Cav-1 causes the formation of a "caveolin-induced Lo phase," as suggested by Langmuir experiments, allowing us to speculate about a possible structural model. These results show that the unique molecular link between Cav-1 and cholesterol can spur functional order in a lipid bilayer strictly derived from biological sources.


Asunto(s)
Caveolina 1/metabolismo , Colesterol/metabolismo , Proteómica/métodos , Animales , Caveolas/metabolismo , Humanos , Difracción de Rayos X
12.
J Exp Clin Cancer Res ; 37(1): 245, 2018 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-30290833

RESUMEN

BACKGROUND: Microenvironment cues involved in melanoma progression are largely unknown. Melanoma is highly influenced in its aggressive phenotype by the changes it determinates in its microenvironment, such as pH decrease, in turn influencing cancer cell invasiveness, progression and tissue remodelling through an abundant secretion of exosomes, dictating cancer strategy to the whole host. A role of exosomes in driving melanoma progression under microenvironmental acidity was never described. METHODS: We studied four differently staged human melanoma lines, reflecting melanoma progression, under microenvironmental acidic pHs pressure ranging between pH 6.0-6.7. To estimate exosome secretion as a function of tumor stage and environmental pH, we applied a technique to generate native fluorescent exosomes characterized by vesicles integrity, size, density, markers expression, and quantifiable by direct FACS analysis. Functional roles of exosomes were tested in migration and invasion tests. Then we performed a comparative proteomic analysis of acid versus control exosomes to elucidate a specific signature involved in melanoma progression. RESULTS: We found that metastatic melanoma secretes a higher exosome amount than primary melanoma, and that acidic pH increases exosome secretion when melanoma is in an intermediate stage, i.e. metastatic non-invasive. We were thus able to show that acidic pH influences the intercellular cross-talk mediated by exosomes. In fact when exposed to exosomes produced in an acidic medium, pH naïve melanoma cells acquire migratory and invasive capacities likely due to transfer of metastatic exosomal proteins, favoring cell motility and angiogenesis. A Prognoscan-based meta-analysis study of proteins enriched in acidic exosomes, identified 11 genes (HRAS, GANAB, CFL2, HSP90B1, HSP90AB1, GSN, HSPA1L, NRAS, HSPA5, TIMP3, HYOU1), significantly correlating with poor prognosis, whose high expression was in part confirmed in bioptic samples of lymph node metastases. CONCLUSIONS: A crucial step of melanoma progression does occur at melanoma intermediate -stage, when extracellular acidic pH induces an abundant release and intra-tumoral uptake of exosomes. Such exosomes are endowed with pro-invasive molecules of clinical relevance, which may provide a signature of melanoma advancement.


Asunto(s)
Exosomas/metabolismo , Melanoma/metabolismo , Línea Celular Tumoral , Progresión de la Enfermedad , Chaperón BiP del Retículo Endoplásmico , Humanos , Melanoma/patología , Microscopía Confocal , Metástasis de la Neoplasia , Microambiente Tumoral
13.
Int J Mol Sci ; 19(5)2018 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-29783743

RESUMEN

In this study, we report how the cholera toxin (CT) A subunit (CTA), the enzyme moiety responsible for signaling alteration in host cells, enters the exosomal pathway, secretes extracellularly, transmits itself to a cell population. The first evidence for long-term transmission of CT's toxic effect via extracellular vesicles was obtained in Chinese hamster ovary (CHO) cells. To follow the CT intracellular route towards exosome secretion, we used a novel strategy for generating metabolically-labeled fluorescent exosomes that can be counted by flow cytometry assay (FACS) and characterized. Our results clearly show the association of CT with exosomes, together with the heat shock protein 90 (HSP90) and Protein Disulfide Isomerase (PDI) molecules, proteins required for translocation of CTA across the ER membrane into the cytoplasm. Confocal microscopy showed direct internalization of CT containing fluorescent exo into CHO cells coupled with morphological changes in the recipient cells that are characteristic of CT action. Moreover, Me665 cells treated with CT-containing exosomes showed an increase in Adenosine 3',5'-Cyclic Monophosphate (cAMP) level, reaching levels comparable to those seen in cells exposed directly to CT. Our results prompt the idea that CT can exploit an exosome-mediated cell communication pathway to extend its pathophysiological action beyond an initial host cell, into a multitude of cells. This finding could have implications for cholera disease pathogenesis and epidemiology.


Asunto(s)
Factores de Ribosilacion-ADP/metabolismo , Toxina del Cólera/metabolismo , Exosomas/metabolismo , Animales , Células CHO , Línea Celular Tumoral , Membrana Celular/metabolismo , Cólera/etiología , Toxina del Cólera/química , Toxina del Cólera/toxicidad , Cricetinae , Cricetulus , AMP Cíclico/metabolismo , Proteínas HSP90 de Choque Térmico/metabolismo , Humanos , Proteína Disulfuro Isomerasas/metabolismo , Subunidades de Proteína/metabolismo , Transporte de Proteínas
14.
Blood Cells Mol Dis ; 61: 58-65, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27667168

RESUMEN

Circulating endothelial progenitor cells (EPCs) have been suggested as a precious source for generating functionally competent endothelial cells (ECs), candidate for various clinical applications. However, the paucity of these progenitor cells and the technical difficulties for their in vitro growth represent a main limitation to their use. In the present study we hypothesized that the paracrine effects of human umbilical vein endothelial cells (HUVECs) may improve endothelial cell generation from cord blood (CB) EPCs. In line with this hypothesis we showed that HUVEC conditioned medium (CM) or co-culture with HUVECs markedly improved the proliferation and differentiation and delayed the senescence of CB EPCs. The endothelial-promoting effect of CM seems to be related to smaller vesicles including exosomes (sEV/exo) contained in this medium and transferred to CB CD34(+) EPCs: in fact, purified preparations of sEV/exo isolated from CM mimicked the effect of CM to sustain endothelial formation. These observations provided the interesting indication that mature ECs exert a stimulatory effect on endothelial cell differentiation from CD34(+) cells.


Asunto(s)
Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Medios de Cultivo Condicionados/farmacología , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Antígenos CD34 , Células Cultivadas , Células Endoteliales/citología , Exosomas , Sangre Fetal/citología , Humanos , Comunicación Paracrina
15.
Methods Mol Biol ; 1448: 217-35, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27317184

RESUMEN

Over the last 10 years, the constant progression in exosome (Exo)-related studies highlighted the importance of these cell-derived nano-sized vesicles in cell biology and pathophysiology. Functional studies on Exo uptake and intracellular trafficking require accurate quantification to assess sufficient and/or necessary Exo particles quantum able to elicit measurable effects on target cells. We used commercially available BODIPY(®) fatty acid analogues to label a primary melanoma cell line (Me501) that highly and spontaneously secrete nanovesicles. Upon addition to cell culture, BODIPY fatty acids are rapidly incorporated into major phospholipid classes ultimately producing fluorescent Exo as direct result of biogenesis. Our metabolic labeling protocol produced bright fluorescent Exo that can be examined and quantified with conventional non-customized flow cytometry (FC) instruments by exploiting their fluorescent emission rather than light-scattering detection. Furthermore, our methodology permits the measurement of single Exo-associated fluorescence transfer to cells making quantitative the correlation between Exo uptake and activation of cellular processes. Thus the protocol presented here appears as an appropriate tool to who wants to investigate mechanisms of Exo functions in that it allows for direct and rapid characterization and quantification of fluorescent Exo number, intensity, size, and eventually evaluation of their kinetic of uptake/secretion in target cells.


Asunto(s)
Transporte Biológico/genética , Exosomas/genética , Citometría de Flujo , Línea Celular Tumoral , Exosomas/metabolismo , Colorantes Fluorescentes/química , Humanos
16.
Toxins (Basel) ; 7(11): 4610-21, 2015 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-26556375

RESUMEN

Eukaryotic cells secrete extracellular vesicles (EVs), either constitutively or in a regulated manner, which represent an important mode of intercellular communication. EVs serve as vehicles for transfer between cells of membrane and cytosolic proteins, lipids and RNA. Furthermore, certain bacterial protein toxins, or possibly their derived messages, can be transferred cell to cell via EVs. We have herein demonstrated that eukaryotic EVs represent an additional route of cell-to-cell propagation for the Escherichia coli protein toxin cytotoxic necrotizing factor 1 (CNF1). Our results prove that EVs from CNF1 pre-infected epithelial cells can induce cytoskeleton changes, Rac1 and NF-κB activation comparable to that triggered by CNF1. The observation that the toxin is detectable inside EVs derived from CNF1-intoxicated cells strongly supports the hypothesis that extracellular vesicles can offer to the toxin a novel route to travel from cell to cell. Since anthrax and tetanus toxins have also been reported to engage in the same process, we can hypothesize that EVs represent a common mechanism exploited by bacterial toxins to enhance their pathogenicity.


Asunto(s)
Toxinas Bacterianas/farmacología , Toxinas Bacterianas/uso terapéutico , Proteínas de Escherichia coli/farmacología , Proteínas de Escherichia coli/uso terapéutico , Vesículas Extracelulares/efectos de los fármacos , Comunicación Celular/efectos de los fármacos , Línea Celular , Línea Celular Tumoral , Citoesqueleto/efectos de los fármacos , Células Epiteliales/efectos de los fármacos , Humanos , FN-kappa B/efectos de los fármacos , Proteína de Unión al GTP rac1/biosíntesis , Proteína de Unión al GTP rac1/efectos de los fármacos
17.
Health Policy ; 119(9): 1197-209, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25737260

RESUMEN

BACKGROUND: Lean seems to be the next revolution for a better, improved, value-based healhcare. In the last 15 years Lean has been increasingly adapted and adopted in healthcare. Accordingly, Lean healthcare has been developing into a major strand of research since the early 2000s. The aim of this work is to present a comprehensive overview of the main issues highlighted by research on implementation of Lean in a complex contest such as the healthcare one. METHOD: Comprehensive literature review was conducted in order to identify empirical and theoretical articles published up to September 2013. Thematic analysis was performed in order to extract and synthesis data. FINDINGS: 243 articles were selected for analysis. Lean is best understood as a means to increase productivity. Hospital is the more explored setting, with emergency and surgery as the pioneer departments. USA appears to be the leading country for number of applications. The theoretical works have been focused mainly on barriers, challenges and success factors. Sustainability, framework for measurement and critical appraisal remain underestimated themes. Evaluations of "system wide approach" are still low in number. CONCLUSION: Even though Lean results appear to be promising, findings so far do not allow to draw a final word on its positive impacts or challenges when introduced in the healthcare sector. Scholars are called to explore further the potentiality and the weaknesses of Lean, above all as for the magnitude of investments required and for the engagement of the whole organization it represents increasingly strategic choice, whilst health professionals, managers and policy makers could and should learn from research how to play a pivotal role for a more effective implementation of lean in different health contexts.


Asunto(s)
Atención a la Salud/organización & administración , Mejoramiento de la Calidad/organización & administración , Atención a la Salud/normas , Humanos , Innovación Organizacional , Calidad de la Atención de Salud/organización & administración
18.
Mol Cell Proteomics ; 12(12): 3948-61, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24045696

RESUMEN

Intracellular pathogens contribute to a significant proportion of infectious diseases worldwide. The successful strategy of evading the immune system by hiding inside host cells is common to all the microorganism classes, which exploit membrane microdomains, enriched in cholesterol and sphingolipids, to invade and colonize the host cell. These assemblies, with distinct biochemical properties, can be isolated by means of flotation in sucrose density gradient centrifugation because they are insoluble in nonionic detergents at low temperature. We analyzed the protein and lipid contents of detergent-resistant membranes from erythrocytes infected by Plasmodium falciparum, the most deadly human malaria parasite. Proteins associated with membrane microdomains of trophic parasite blood stages (trophozoites) include an abundance of chaperones, molecules involved in vesicular trafficking, and enzymes implicated in host hemoglobin degradation. About 60% of the identified proteins contain a predicted localization signal suggesting a role of membrane microdomains in protein sorting/trafficking. To validate our proteomic data, we raised antibodies against six Plasmodium proteins not characterized previously. All the selected candidates were recovered in floating low-density fractions after density gradient centrifugation. The analyzed proteins localized either to internal organelles, such as the mitochondrion and the endoplasmic reticulum, or to exported membrane structures, the parasitophorous vacuole membrane and Maurer's clefts, implicated in targeting parasite proteins to the host erythrocyte cytosol or surface. The relative abundance of cholesterol and phospholipid species varies in gradient fractions containing detergent-resistant membranes, suggesting heterogeneity in the lipid composition of the isolated microdomain population. This study is the first report showing the presence of cholesterol-rich microdomains with distinct properties and subcellular localization in trophic stages of Plasmodium falciparum.


Asunto(s)
Membrana Eritrocítica/química , Microdominios de Membrana/química , Plasmodium falciparum/genética , Proteoma/genética , Proteínas Protozoarias/genética , Trofozoítos/metabolismo , Anticuerpos/química , Centrifugación por Gradiente de Densidad , Colesterol/química , Cisteína Endopeptidasas/genética , Cisteína Endopeptidasas/metabolismo , Detergentes/química , Membrana Eritrocítica/parasitología , Técnica del Anticuerpo Fluorescente Indirecta , Expresión Génica , Interacciones Huésped-Parásitos , Humanos , Membranas Intracelulares/química , Microdominios de Membrana/parasitología , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Anotación de Secuencia Molecular , Fosfolípidos/química , Plasmodium falciparum/química , Plasmodium falciparum/metabolismo , Transporte de Proteínas , Proteoma/metabolismo , Proteínas Protozoarias/metabolismo , Trofozoítos/química
19.
Int J Cancer ; 130(6): 1273-83, 2012 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-21445970

RESUMEN

Caveolae have been indicated as a center of cytoskeleton regulation for Src kinase/Rho GTPase signaling. In addition, Src recruitment on intact cortical actin cytoskeleton appears to be required for bFGF/FGFR signal activation. Recently, we established a relationship between caveolin-1 (Cav-1) expression and cell migration in human malignant melanoma, constitutively activated by a bFGF autoregulatory loop. This work intends to investigate whether caveolae's asset, through bFGF/FGFR/c-Src/Rho signaling, could be related to melanoma cell anchorage. Accordingly, we revealed the existence of a FGFR/Src kinase pathway in Cav-1 enriched detergent-resistant membranes (DRMs) of Me665/1 metastatic melanoma cells, as confirmed by FGFR silencing. Moreover, we determined the expression and phosphorylation levels of Cav-1/Src/Erk signal pathway as a function of FGFR activation and cell density. A sucrose density gradient ultracentrifugation was employed to monitor Cav-1 membrane association and buoyancy in Me665/1 cells treated for actin fragmentation or for altered phosphorylation signals. As a result, melanoma cells show remarkable resistance to Cav-1 disassembly, together with persisting cell signal activity, being Src and Cav-1 crucial modulators of Rho GTPases. In conclusion, our study primarily highlights, in a metastatic melanoma cell line expressing caveolin, the circumstances whereby caveola structural and functional endurance enables the FGFR/Src/Rho GTPases pathway to keep on cell progression.


Asunto(s)
Caveolina 1/metabolismo , Melanoma/metabolismo , Receptores de Factores de Crecimiento de Fibroblastos/metabolismo , Proteínas de Unión al GTP rho/metabolismo , Familia-src Quinasas/metabolismo , Actinas/metabolismo , Caveolina 1/genética , Recuento de Células , Línea Celular Tumoral , Membrana Celular/genética , Membrana Celular/metabolismo , Movimiento Celular/fisiología , Citoesqueleto/genética , Citoesqueleto/metabolismo , Humanos , Sistema de Señalización de MAP Quinasas , Melanoma/genética , Melanoma/patología , Fosforilación , Receptores de Factores de Crecimiento de Fibroblastos/genética , Transducción de Señal , Proteínas de Unión al GTP rho/genética , Familia-src Quinasas/genética
20.
Health Serv Manage Res ; 23(4): 172-80, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21097728

RESUMEN

In this paper, we aim to discuss the implications and lessons that can be learnt from the ongoing process of federalism affecting the Italian National Health System (INHS). Many countries are currently taking decisions concerning the decentralization or re-centralization of their health-care systems, with several key issues that are illustrated in the recent history of the INHS. The decentralization process of INHS has produced mixed results, as some regions took advantage of it to strengthen their systems, whereas others were not capable of developing an effective steering role. We argue that the mutual reinforcement of the decentralization and recentralization processes is not paradoxical, but is actually an effective way for the State to maintain control over the equity and efficiency of its health-care system while decentralizing at a regional level. In this perspective, we provide evidence backing up some of the assumptions made in previous works as well as new food-for thought - specifically on how governmentality and federalism should meet - to reshape the debate on decentralization in health care.


Asunto(s)
Programas Nacionales de Salud/organización & administración , Política , Eficiencia Organizacional , Humanos , Italia , Programas Nacionales de Salud/economía
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