203 research outputs found

    β2 integrin-mediated cell-cell contact transfers active myeloperoxidase from neutrophils to endothelial cells

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    Atherosclerosis and vasculitis both feature inflammation mediated by neutrophil-endothelial-cell (EC) contact. Neutrophil myeloperoxidase (MPO) can disrupt normal EC function, although the mechanism(s) by which MPO is transferred to EC are unknown. We tested the hypothesis that close, beta2-integrin-dependent neutrophil-EC contact mediates MPO transfer from neutrophils to EC. We used sensitive MPO assays and flow cytometry to detect MPO in EC and demonstrate that EC acquired MPO when contacted by neutrophils directly but not when EC and neutrophils were separated in transwells. The transfer was dependent on neutrophil number, exposure time, and incubation temperature. Transfer occurred in several EC types, increased with endotoxin, was not accompanied by MPO release into the medium and was not abrogated by inhibiting degranulation to secretagogues. Confocal microscopy showed MPO internalization by EC with cytoplasmic and nuclear staining. Neutrophils and EC formed intimate contact sites demonstrated by electron microscopy. Blocking CD11b or CD18 beta2-integrin chains, or using neutrophils from CD11b gene-deleted mice, reduced MPO transfer. EC-acquired MPO was enzymatically active, as demonstrated by its ability to oxidize the fluorescent probe aminophenyl fluorescein in the presence of a hydrogen peroxide source. The data suggest an alternative to EC uptake of soluble MPO, namely the cell contact-dependent, {beta}2-integrin-mediated transfer from neutrophils. The findings could be of therapeutic relevance in atherosclerosis and vasculitis

    Competitively disrupting the neutrophil-specific receptor-autoantigen CD177:proteinase 3 membrane complex reduces anti-PR3 antibody-induced neutrophil activation

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    CD177 is a neutrophil-specific receptor presenting the proteinase 3 (PR3) autoantigen on the neutrophil surface. CD177 expression is restricted to a neutrophil subset, resulting in CD177(pos)/mPR3(high) and CD177(neg)/mPR3(low) populations. The CD177(pos)/mPR3(high) subset has implications for anti-neutrophil cytoplasmic autoantibody (ANCA)-associated autoimmune vasculitis (AAV), wherein patients harbor PR3-specific ANCAs that activate neutrophils for degranulation. Here we generated high-affinity anti-CD177 monoclonal antibodies, some of which interfered with PR3 binding to CD177 (PR3 "blockers") as determined by surface plasmon resonance spectroscopy, and used them to test the effect of competing PR3 from the surface of CD177(pos) neutrophils. Because intact anti-CD177 antibodies also caused neutrophil activation, we prepared non-activating Fab fragments of a PR3 blocker and non-blocker that bound specifically to CD177(pos) neutrophils. We observed that Fab blocker clone 40, but not non-blocker clone 80, dose-dependently reduced anti-PR3 antibody binding to CD177(pos) neutrophils. Importantly, preincubation with clone 40 significantly reduced respiratory burst in primed neutrophils challenged with either monoclonal antibodies to PR3 or PR3-ANCA IgG from AAV patients. After separating the two CD177/mPR3 neutrophil subsets from individual donors by magnetic sorting, we found that PR3-ANCAs provoked significantly more superoxide production in CD177(pos)/mPR3(high) than in CD177(neg)/mPR3(low) neutrophils, and that anti-CD177 Fab clone 40 reduced the superoxide production of CD177(pos) cells to the level of the CD177(neg) cells. Our data demonstrate the importance of the CD177:PR3 membrane complex in maintaining a high ANCA epitope density and thereby underscore the contribution of CD177 to the severity of PR3-ANCA diseases

    Calorie Restriction in Adulthood Reduces Hepatic Disorders Induced by Transient Postnatal Overfeeding in Mice.

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    Impaired early nutrition influences the risk of developing metabolic disorders in later life. We observed that transient postnatal overfeeding (OF) in mice induces long-term hepatic alterations, characterized by microsteatosis, fibrosis associated with oxidative stress (OS), and stress-induced premature senescence (SIPS). In this study, we investigated whether such changes can be reversed by moderate calorie restriction (CR). C57BL/6 male mice pups were maintained during lactation in litters adjusted to nine pups in the normal feeding (NF) group and three pups in the transient postnatal OF group. At six months of age, adult mice from the NF and OF groups were randomly assigned to an ad libitum diet or CR (daily energy supply reduced by 20%) for one month. In each group, at the age of seven months, analysis of liver structure, liver markers of OS (superoxide anion, antioxidant defenses), and SIPS (lipofuscin, p53, p21, p16, pRb/Rb, Acp53, sirtuin-1) were performed. CR in the OF group reduced microsteatosis, decreased levels of superoxide anion, and increased protein expression of catalase and superoxide dismutase. Moreover, CR decreased lipofuscin staining, p21, p53, Acp53, and p16 but increased pRb/Rb and sirtuin-1 protein expression. CR did not affect the NF group. These results suggest that CR reduces hepatic disorders induced by OF

    Isolated adult hypoganglionosis presenting as sigmoid volvulus: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Isolated hypoganglionosis is a rare cause of intestinal innervation defects. It is characterized by sparse and small myenteric ganglia, absent or low acetylcholinesterase activity in the lamina propria and hypertrophy of the muscularis mucosae, principally in the region of the colon and rectum. It accounts for 5% of all intestinal neuronal malformations. To the best of our knowledge, only 92 cases of isolated hypoganglionosis were reported from 1978 to 2009. Isolated hypoganglionosis usually manifests as enterocolitis or poor bowel function, and is diagnosed in infancy or childhood. We report the first case of isolated hypoganglionosis presenting with sigmoid volvulus in a 34-year-old woman.</p> <p>Case presentation</p> <p>A 34-year-old Asian woman had progressively increasing abdominal pain and had not passed stool or flatus for two days. A physical examination revealed a distended abdomen with sluggish gut sounds. A computerized tomography (CT) scan demonstrated gross dilatation of the sigmoid colon (maximal diameter 14.3 cm) suggestive of sigmoid volvulus. During emergency laparotomy, sigmoidectomy with a side-to-side colorectal anastomosis was performed. Histopathology of the resected specimen showed occasional ganglion cells and hypertrophied nerve bundles in the muscle layers, suggesting hypoganglionosis. Colonoscopy was performed, and multiple full-thickness biopsies were taken that showed hypoganglionosis of the entire large bowel. Our patient underwent total colectomy with an ileorectal anastomosis. Subsequently our patient reported a dramatic improvement in her bowel function.</p> <p>Conclusions</p> <p>Isolated hypoganglionosis is a rare cause of intestinal dysganglionosis and cannot be differentiated from Hirschsprung's disease based on clinical presentation. This case report describes an atypical presentation of the disease. A definitive diagnosis requires histopathological analysis of full-thickness intestinal biopsies. Treatment should be tailored to the extent of hypoganglionosis.</p

    The contribution of varietal thiols in the diverse aroma of Italian monovarietal white wines

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    Thanks to their low odor detection thresholds, free varietal thiols (VTs) play a key role in the primary aroma of wines, to which they confer an intense scent reminiscent of box tree, grapefruit, citrus fruits, passionfruit and cat urine odor. Excluding wines from a few VT-rich grapevine cultivars, VTs appear to be present in most cultivars at trace levels, although a comprehensive dataset is still missing. The low concentration of VTs combined with their high reactivity and matrix complexity make their determination in wines a challenging task. In this research an optimized liquid chromatography - tandem mass spectrometry (LC-MS/MS) method was validated and used for the quantification of 4-methyl-4-sulfanylpentan-2-one (4-MSP), 3-sulfanylhexan-1-ol (3-SH), 3-sulfanylhexyl acetate (3-SHA) and ethyl 3-sulfanylpropionate (E3SP) in 246 samples (vintage 2019) representative of 18 monovarietal Italian white wines. VTs were detected in all cultivars even though higher values of 3-SH were found in Lugana, Müller-Thurgau and Verdicchio cultivars. Müller-Thurgau wines showed the highest level of 4-MSP, that was mainly correlated to the odor descriptors of passionfruit and box tree/cat urine. The VTs composition of Müller-Thurgau was confirmed on a second set of 50 wines from different vintages. From a sensory perspective, the samples of Müller-Thurgau showed the best positive correlations between chemical variables and the odor descriptors thiol note, passion fruit and box tree/cat urine. These notes are significantly related to 4-MSP, suggesting that it could play a relevant olfactory role for the aroma of Müller-Thurgau wines. Sorting analysis allowed to group these wines according to their thiolic characteristics. The chemical variables and the odor descriptors attributable to the thiol notes are important for Müller-Thurgau and Lugana wines, while the contribution of thiol notes was sensorially negligible for the other wines.18openNoMinistry of Education, University and Research (MIUR) under the PRIN 2017 grant (Prot. 2017RXFFRR, CUP code B38D19000120006)Carlin, Silvia; Piergiovanni, Maurizio; Pittari, Elisabetta; Tiziana Lisanti, Maria; Moio, Luigi; Piombino, Paola; Marangon, Matteo; Curioni, Andrea; Rolle, Luca; Rìo Segade, Susana; Versari, Andrea; Ricci, Arianna; Parpinello, Giuseppina Paola; Luzzini, Giovanni; Ugliano, Maurizio; Perenzoni, Daniele; Vrhovsek, Urska; Mattivi, FulvioCarlin, S.; Piergiovanni, M.; Pittari, E.; Tiziana Lisanti, M.; Moio, L.; Piombino, P.; Marangon, M.; Curioni, A.; Rolle, L.; Rìo Segade, S.; Versari, A.; Ricci, A.; Parpinello, G.P.; Luzzini, G.; Ugliano, M.; Perenzoni, D.; Vrhovsek, U.; Mattivi, F

    OLED-on-silicon for near-to-eye microdisplays and sensing

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    Smart eyewear featuring near-to-eye (NTE) displays have evolved as major devices for wearable displays, which hold potential to become adopted by consumers soon. Tiny OLED-on-silicon microdisplays (<1” screen diagonal) are a key component of eyewear displays, creating images from active-matrix organic light emitting diodes (AM-OLED), similar to those that have become popular in mobile phone displays

    Analysis of bacterial profiles of AGBRESA participants – a study concerning terrestrial astronauts under simulated microgravity

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    Introduction: Long-term space missions are accompanied by harmful environmental conditions like microgravity. Due to the reduced gravity, astronauts adapt to their environment resulting in tissue fluidic shifts. Since the knowledge about microbiome data in space is sparse and conduction of experiments at the ISS is complex, suitable analogs are needed. Therefore, the first cooperative bed-rest study called Artificial Gravity Bed-Rest study with ESA (AGBRESA), by NASA, ESA and DLR offered optimal features to investigate possible correlations between microbial shifts and physiological microgravity by using -6° head-downtilt (HDT). The aim of this survey was to identify changes within the standardized conditions, such as diet and wrongly distributed tissue fluids to reveal causal connections among health state and microbial communities

    MicroRNAs Dynamically Remodel Gastrointestinal Smooth Muscle Cells

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    Smooth muscle cells (SMCs) express a unique set of microRNAs (miRNAs) which regulate and maintain the differentiation state of SMCs. The goal of this study was to investigate the role of miRNAs during the development of gastrointestinal (GI) SMCs in a transgenic animal model. We generated SMC-specific Dicer null animals that express the reporter, green fluorescence protein, in a SMC-specific manner. SMC-specific knockout of Dicer prevented SMC miRNA biogenesis, causing dramatic changes in phenotype, function, and global gene expression in SMCs: the mutant mice developed severe dilation of the intestinal tract associated with the thinning and destruction of the smooth muscle (SM) layers; contractile motility in the mutant intestine was dramatically decreased; and SM contractile genes and transcriptional regulators were extensively down-regulated in the mutant SMCs. Profiling and bioinformatic analyses showed that SMC phenotype is regulated by a complex network of positive and negative feedback by SMC miRNAs, serum response factor (SRF), and other transcriptional factors. Taken together, our data suggest that SMC miRNAs are required for the development and survival of SMCs in the GI tract
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