72 research outputs found

    Role of extracellular microenvironment on regenerative bone tissue capacity

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    In the present study, I aimed to investigate how acidic extracellular pH can affect MSCs behavior in terms of proliferation, osteogenic potential, activation of autophagy, and release of inflammatory molecules, and I looked for potential osteo- and chondro-progenitor cell populations activated during the repair of bone injury in the periosteum of a mouse model in vivo. I cultured human MSCs in acidic medium, and I observed a decrease in their proliferation and mineralization potential, and an increase in the release of inflammatory cytokines. The survival mechanism of autophagy was found to be activated by MSCs in both acidic and physiological conditions. These observations have allowed to further characterize human MSCs biology in a non-physiological context, typical of patients with an altered acid-base balance. An altered extracellular microenvironment is also typical of the early stages of the fracture healing process, and the identification of cells participating in bone repair is necessary to eventually improve therapeutic approaches of regenerative medicine. Through the use of a transgenic mouse model of lineage tracing, I observed that αSMA+ periosteal cells identify osteo– and chondro-progenitors activated after fracture, although only a low percentage of them represents long-term progenitors. Furthermore, other markers previously characterized in the bone marrow are suitable for identification of progenitor cell populations in the periosteum. Further studies are needed, especially aimed to better investigate different surface markers combinations, and the ability of these progenitor cells to form bone in vivo. Through the entire work, I highlighted the importance of the extracellular microenvironment in the modulation of MSCs behavior, and I contributed to the identification of osteo- and chondro-progenitors involved in bone repair, aiming to improve approaches of regenerative medicine, especially in patients in which the healing process is impaired by pathological conditions

    Electro-magnetic field promotes osteogenic differentiation of BM-hMSCs through a selective action on Ca(2+)-related mechanisms

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    Exposure to Pulsed Electromagnetic Field (PEMF) has been shown to affect proliferation and differentiation of human mesenchymal stem cells derived from bone marrow stroma (BM-hMSC). These cells offer considerable promise in the field of regenerative medicine, but their clinical application is hampered by major limitations such as poor availability and the time required to differentiate up to a stage suitable for implantation. For this reason, several research efforts are focusing on identifying strategies to speed up the differentiation process. In this work we investigated the in vitro effect of PEMF on Ca2+-related mechanisms promoting the osteogenic differentiation of BM-hMSC. Cells were daily exposed to PEMF while subjected to osteogenic differentiation and various Ca2+-related mechanisms were monitored using multiple approaches for identifying functional and structural modifications related to this process. The results indicate that PEMF exposure promotes chemically induced osteogenesis by mechanisms that mainly interfere with some of the calcium-related osteogenic pathways, such as permeation and regulation of cytosolic concentration, leaving others, such as extracellular deposition, unaffected. The PEMF effect is primarily associated to early enhancement of intracellular calcium concentration, which is proposed here as a reliable hallmark of the osteogenic developmental stage

    Microplastics ingestion in the ephyra stage of Aurelia sp. triggers acute and behavioral responses

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    For the first time, we report a correspondence between microplastics (MP) ingestion and ecotoxicological effects in gelatinous zooplankton (Cnidarian jellyfish). The ephyra stage of the jellyfish Aurelia sp. was exposed to both environmental and high concentrations of fluorescent 1–4 μm polyethylene MP (0.01–10 mg/L). After 24 and 48 h, MP accumulation, acute (Immobility) and behavioral (Frequency pulsation) endpoints were investigated. MP were detected by confocal and tomographic investigations on gelatinous body and mouth, either attached on the surface or ingested. This interaction was responsible for impairing ephyrae survival and behavior at all tested concentrations after 24 h. Acute and behavioral effects were also related to mechanical disturbance, caused by MP, triggering a loss of radial symmetry. Contaminated ephyrae exposed to clean seawater showed full recovery after 72 h highlighting the organisms without the microspheres, attached on body jellyfish surface around the mouth and lappets. In conclusion, short-term exposure to MP affects ephyrae jellyfish health, impairing both their survival and behavior. Polyethylene MP temporarily affect both Immobility and Frequency of pulsation of Aurelia sp. jellyfish. This study provides a first step towards understanding and clarifying the potential impacts of MP contamination in gelatinous zooplankton

    Relationships between optical aggregometry (type Born) and flow cytometry in evaluating ADP-induced platelet activation

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    Background: Platelet response to activating agents is used to monitor the efficacy of anti-aggregation therapies. The aim of our study has been to demonstrate the existence of relationships between early events of ADP-induced platelet activation, measured by flow cytometry and platelet-rich plasma aggregation,quantified by optical aggregometry. Methods: We evaluated peripheral blood of 12 donors. The following parameters were quantified by cytometry after stimulation with adenosine diphosphate (ADP) (0.5, 1, 2, 5, 10, 20 uM): CD62P (P-selectin) and PAC-1 expression, and cytosolic Ca2+ mobilization. Aggregation was measured by optical aggregometry. We also studied 13 patients, undergoing coronary stenting, treated with aspirin (before procedure) or with aspirin plus clopidogrel (after procedure). We evaluated CD62P and PAC-1 expression, aggregation,and vasodilator-stimulated phopshoprotein phosphorylation (platelet reactivity index, PRI). Results: Flow procedures were more sensitive than aggregometry, with a lowest interindividual variability. Linear relationships existed in donors between CD62P expression and Ca2+ mobilization (P<0.0001),and between aggregation and Ca2+ mobilization (P<0.0001). Linear relationships existed between aggregation and CD62P expression, as percentage (P<0.0001), or relative fluorescence intensity (RFI) (P<0.0001). Exponential equations related aggregation and PAC-1 expression, as percentage (P<0.0001), or RFI (P<0.0001). Linear relationships between aggregation and CD62P expression (as percentage) existed in the patients before (P=0.0022) and after procedure (P=0.0020. Exponential relationships between aggregation and PAC-1 expression (as percentage) existed before (P=0.0012) and after procedure (P=0.0024). Linear correlations related aggregation response predicted on CD62P expression, and measured aggregation inhibition after clopidogrel (P=0.0013) as well as predicted aggregation and PRI inhibition (P=0.0031). Conclusions: Tight relationships between aggregation and cytometric quantification of platelet markers in whole blood, in particular CD62P, allow to predict aggregation response to ADP from flow data in patients treated with aspirin alone or with aspirin plus clopidogrel

    Verso l\u27allargamento dell\u27Unione europea. Una panoramica sui dati che i cittadini dei nuovi Stati Membri dovranno indicare per registrare un nome a dominio sotto il ccTLD "it"

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    This work is aimed at giving the information that citizen of the EU must declare in the letter of assumption of responsibility to obtain a domain name under the ccTLD \u27it\u2

    Development of label-free biophysical markers in osteogenic maturation

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    The spatial and temporal changes of morphological and mechanical properties of living cells reflect complex functionally-associated processes. Monitoring these modifications could provide a direct information on the cellular functional state. Here we present an integrated biophysical approach to the quantification of the morphological and mechanical phenotype of single cells along a maturation pathway. Specifically, quantitative phase microscopy and single cell biomechanical testing were applied to the characterization of the maturation of human foetal osteoblasts, demonstrating the ability to identify effective label-free biomarkers along this fundamental biological process

    Patrón de abundancia espacio-temporal de la gamba de altura, Parapenaeus longirostris, y de la cigala, Nephrops norvegicus, en las aguas mediterráneas europeas

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    The main characteristics concerning the distribution of two of the most important decapod crustaceans of commercial interest in the Mediterranean Sea, the deep-water rose shrimp, Parapenaeus longirostris, and the Norway lobster, Nephrops norvegicus, are studied in the European Mediterranean waters. The study is based on data collected under the MEDITS trawl surveys from 1994 to 2015 from the Gibraltar Straits to the northeastern Levantine Basin (Cyprus waters). The observed differences can be interpreted as different responses to environmental drivers related to the differing life history traits of the two species. In fact, N. norvegicus is a long-living, benthic burrowing species with low growth and mortality rates, while P. longirostris is an epibenthic, short-living species characterized by higher rates of growth and mortality.Se investigaron las características de la distribución de dos de los crustáceos decápodos más importantes a nivel comercial del mar Mediterráneo, la gamba de altura, Parapenaeus longirostris y la cigala, Nephrops norvegicus, en aguas mediterráneas europeas. El presente estudio se basa en datos recopilados en las campañas de pesca experimental de arrastre MEDITS, relizadas de 1994 a 2015 desde el estrecho de Gibraltar hasta la cuenca levantina nororiental (aguas de Chipre). Las diferencias observadas en el patrón de distribución se pueden interpretar como distintas respuestas a factores ambientales relacionados con los diferentes rasgos del ciclo vital de las dos especies. De hecho, N. norvegicus es una especie bentónica de vida larga, con bajas tasas de crecimiento y mortalidad, mientras que P. longirostris es una especie epibentónica de vida corta, caracterizada por tasas más altas de crecimiento y de mortalidad

    Impact of two Erwinia sp. on the response of diverse Pisum sativum genotypes under salt stress

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    The current study reveals that two non-pathogenic strains of Erwinia sp. are diferent in their PGP traits. By using an integrated approach, a picture of the pea plant status in three genotypes subjected to a salt stress condition was obtained and the role of the two bacterial considered Erwinia sp. strains has been highlighted. Results showed the relevance of plant genotype in determining the response to bacterial inoculants as well as the diferences in the plant mechanisms activated to cope with the stress in the diferent plant/strain combination. Overall, this study emphasizes the importance of understanding the molecular and biochemical processes occurring in plant–microbe interactions at genotype level, and the influence on plant responses to environmental stresses. Further analyses are needed to clarify the behaviour of the three genotypes, such as the leaf water potential, and to verify the efects of the bacterial inoculation in feld conditions, subjectd by an increased environmental unpredictability due to the climate change scenarioCurrently, salinization is impacting more than 50% of arable land, posing a significant challenge to agriculture globally. Salt causes osmotic and ionic stress, determining cell dehydration, ion homeostasis, and metabolic process alteration, thus negatively influencing plant development. A promising sustainable approach to improve plant tolerance to salinity is the use of plant growth-promoting bacteria (PGPB). This work aimed to characterize two bacterial strains, that have been isolated from pea root nodules, initially called PG1 and PG2, and assess their impact on growth, physiological, biochemical, and molecular parameters in three pea genotypes (Merveille de Kelvedon, Lincoln, Meraviglia d'Italia) under salinity. Bacterial strains were molecularly identified, and characterized by in vitro assays to evaluate the plant growth promoting abilities. Both strains were identified as Erwinia sp., demonstrating in vitro biosynthesis of IAA, ACC deaminase activity, as well as the capacity to grow in presence of NaCl and PEG. Considering the inoculation of plants, pea biometric parameters were unaffected by the presence of the bacteria, independently by the considered genotype. Conversely, the three pea genotypes differed in the regulation of antioxidant genes coding for catalase (PsCAT) and superoxide dismutase (PsSOD). The highest proline levels (212.88 μmol g-1) were detected in salt-stressed Lincoln plants inoculated with PG1, along with the up-regulation of PsSOD and PsCAT. Conversely, PG2 inoculation resulted in the lowest proline levels that were observed in Lincoln and Meraviglia d'Italia (35.39 and 23.67 μmol g-1, respectively). Overall, this study highlights the potential of these two strains as beneficial plant growth-promoting bacteria in saline environments, showing that their inoculation modulates responses in pea plants, affecting antioxidant gene expression and proline accumulation
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