RESUMEN
Cystic fibrosis is a life-shortening genetic disorder, caused by mutations in the gene that encodes cystic fibrosis transmembrane-conductance regulator, a cAMP-activated chloride and bicarbonate channel. Persistent neutrophilic inflammation is a major contributor to cystic fibrosis lung disease. However, how cystic fibrosis transmembrane-conductance regulator loss of function leads to excessive inflammation and its clinical sequela remains incompletely understood. In this study, neutrophils from F508del-CF and healthy control participants were compared for gene transcription. We found that cystic fibrosis circulating neutrophils have a prematurely primed basal state with significantly higher scores for activation, chemotaxis, immune signaling, and pattern recognition. Such an irregular basal state appeared not related to the blood environment and was also observed in neutrophils derived from the F508del-CF HL-60 cell line, indicating an innate characteristic of the phenotype. Lipopolysaccharides (LPS) stimulation drastically shifted the transcriptional landscape of healthy control neutrophils toward a robust immune response; however, cystic fibrosis neutrophils were immune-exhausted, reflected by abnormal cell aging and fate determination in gene programming. Moreover, cystic fibrosis sputum neutrophils differed significantly from cystic fibrosis circulating neutrophils in gene transcription with increased inflammatory response, aging, apoptosis, and necrosis, suggesting additional environmental influences on the neutrophils in cystic fibrosis lungs. Taken together, our data indicate that loss of cystic fibrosis transmembrane-conductance regulator function has intrinsic effects on neutrophil immune programming, leading to premature priming and dysregulated response to challenge.
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Fibrosis Quística , Humanos , Fibrosis Quística/genética , Neutrófilos , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Inmunidad , Inflamación , MutaciónRESUMEN
Cystic fibrosis (CF) is an autosomal recessive genetic disorder caused by mutations in the CF Transmembrane-conductance Regulator (CFTR) gene. The most severe pathologies of CF occur in the lung, manifesting as chronic bacterial infection, persistent neutrophilic inflammation, and mucopurulent airway obstruction. Despite increasing knowledge of the CF primary defect and the resulting clinical sequelae, the relationship between the CFTR loss of function and the neutrophilic inflammation remains incompletely understood. Here, we report that loss of CFTR function in macrophages causes extended lung inflammation. After intratracheal inoculation with Pseudomonas aeruginosa, mice with a macrophage-specific Cftr-knockout (Mac-CF) were able to mount an effective host defense to clear the bacterial infection. However, three days post-inoculation, Mac-CF lungs demonstrated significantly more neutrophil infiltration and higher levels of inflammatory cytokines, suggesting that Mac-CF mice had a slower resolution of inflammation. Single-cell RNA sequencing revealed that absence of CFTR in the macrophages altered the cell transcriptional program, affecting the cell inflammatory and immune responses, antioxidant system, and mitochondrial respiration. Thus, loss of CFTR function in macrophages influences cell homeostasis, leading to a dysregulated cellular response to infection that may exacerbate CF lung disease.
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Regulador de Conductancia de Transmembrana de Fibrosis Quística , Fibrosis Quística , Ratones , Animales , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Fibrosis Quística/complicaciones , Pulmón/patología , Macrófagos/patología , Inflamación/patologíaRESUMEN
Cystic fibrosis is a life-threatening genetic disorder caused by mutations in the CFTR chloride channel. Clinically, over 90% of patients with cystic fibrosis succumb to pulmonary complications precipitated by chronic bacterial infections, predominantly by Pseudomonas aeruginosa and Staphylococcus aureus. Despite the well-characterized gene defect and clearly defined clinical sequelae of cystic fibrosis, the critical link between the chloride channel defect and the host defense failure against these specific pathogens has not been established. Previous research from us and others has uncovered that neutrophils from patients with cystic fibrosis are defective in phagosomal production of hypochlorous acid, a potent microbicidal oxidant. Here we report our studies to investigate if this defect in hypochlorous acid production provides P. aeruginosa and S. aureus with a selective advantage in cystic fibrosis lungs. A polymicrobial mixture of cystic fibrosis pathogens (P. aeruginosa and S. aureus) and non-cystic fibrosis pathogens (Streptococcus pneumoniae, Klebsiella pneumoniae, and Escherichia coli) was exposed to varied concentrations of hypochlorous acid. The cystic fibrosis pathogens withstood higher concentrations of hypochlorous acid than did the non-cystic fibrosis pathogens. Neutrophils derived from F508del-CFTR HL-60 cells killed P. aeruginosa less efficiently than did the wild-type counterparts in the polymicrobial setting. After intratracheal challenge in wild-type and cystic fibrosis mice, the cystic fibrosis pathogens outcompeted the non-cystic fibrosis pathogens and exhibited greater survival in the cystic fibrosis lungs. Taken together, these data indicate that reduced hypochlorous acid production due to the absence of CFTR function creates an environment in cystic fibrosis neutrophils that provides a survival advantage to specific microbes-namely, S. aureus and P. aeruginosa-in the cystic fibrosis lungs.
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Fibrosis Quística , Infecciones por Pseudomonas , Animales , Ratones , Neutrófilos/metabolismo , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Ácido Hipocloroso/metabolismo , Staphylococcus aureus/metabolismo , Fibrosis Quística/patología , Pulmón/patología , Fibrosis , Pseudomonas aeruginosa , Infecciones por Pseudomonas/microbiologíaRESUMEN
Cystic fibrosis (CF) is a life-shortening genetic disorder, caused by mutations in the gene that encodes Cystic Fibrosis Transmembrane-conductance Regulator (CFTR), a cAMP-activated chloride and bicarbonate channel. Although multiple organ systems can be affected, CF lung disease claims the most morbidity and mortality due to chronic bacterial infection, persistent neutrophilic inflammation, and mucopurulent airway obstruction. Despite the clear predominance of neutrophils in these pathologies, how CFTR loss-of-function affects these cells per se remains incompletely understood. Here, we report the profiling and comparing of transcriptional signatures of peripheral blood neutrophils from CF participants and healthy human controls (HC) at the single-cell level. Circulating CF neutrophils had an aberrant basal state with significantly higher scores for activation, chemotaxis, immune signaling, and pattern recognition, suggesting that CF neutrophils in blood are prematurely primed. Such an abnormal basal state was also observed in neutrophils derived from an F508del-CF HL-60 cell line, indicating an innate characteristic of the phenotype. LPS stimulation drastically shifted the transcriptional landscape of HC circulating neutrophils towards a robust immune response, however, CF neutrophils were immune-exhausted. Moreover, CF blood neutrophils differed significantly from CF sputum neutrophils in gene programming with respect to neutrophil activation and aging, as well as inflammatory signaling, highlighting additional environmental influences on the neutrophils in CF lungs. Taken together, loss of CFTR function has intrinsic effects on neutrophil immune programming that leads to premature priming and dysregulated response to challenge.
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Cystic fibrosis (CF) is a life-threatening genetic disorder, caused by mutations in the CF transmembrane-conductance regulator gene (cftr) that encodes CFTR, a cAMP-activated chloride and bicarbonate channel. Clinically, CF lung disease dominates the adult patient population. However, its gastrointestinal illness claims the early morbidity and mortality, manifesting as intestinal dysbiosis, inflammation and obstruction. As CF is widely accepted as a disease of epithelial dysfunction, it is unknown whether CFTR loss-of-function in immune cells contributes to these clinical outcomes. Using cftr genetic knockout and bone marrow transplantation mouse models, we performed 16S rRNA gene sequencing of the intestinal microbes. Here we show that cftr deletion in both epithelial and immune cells collectively influence the intestinal microbiota. However, the immune defect is a major factor determining the dysbiosis in the small intestine, while the epithelial defect largely influences that in the large intestine. This finding revises the current concept by suggesting that CF epithelial defect and immune defect play differential roles in CF intestinal disease.
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Fibrosis Quística , Microbioma Gastrointestinal , Humanos , Ratones , Animales , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Disbiosis/genética , ARN Ribosómico 16S/genética , Cloruros , Bicarbonatos , Fibrosis Quística/genéticaRESUMEN
BACKGROUND/AIM: The proportion of patients with liver metastases in patients with appendiceal versus colorectal adenocarcinomas was 3.1 percent and 24 percent, respectively, in our peritonectomy centre. From our internal analyses, carcinoembryonic antigen (CEA) was potentially involved. A hypothesis was proposed regarding the natural progression of appendiceal adenocarcinoma. To support this, a systematic review and meta-analysis were performed to examine whether there was a difference in the proportion of patients with an elevated CEA in appendiceal versus colorectal adenocarcinoma patients in the current literature. MATERIALS AND METHODS: Medline (PubMed), EMBASE (Ovid), Cochrane Central Register of Controlled Trials (CENTRAL), Cumulative Index to Nursing and Allied Health Literature, Clinicaltrials.gov, Web of Science, and Google Scholar were searched. All studies involving patients with appendiceal and/or colorectal adenocarcinoma were eligible. Data were analysed by grouping appendiceal and colorectal adenocarcinoma in separate meta-analyses, and then comparing their weighted proportions of elevated CEA. Principal summary measures were weighted proportions of patients with elevated CEA. RESULTS: From the initial identification of 1,928 articles, 136 articles were included in the final synthesis. Ninety-two articles were included in the meta-analysis. Proportions of appendiceal and colorectal adenocarcinoma with elevated CEA were 56% (95%CI=47-65%) and 42% (95%CI=38-46%), respectively (p=0.0001). CONCLUSION: Patients with appendiceal adenocarcinoma had a higher proportion of CEA than those with colorectal adenocarcinoma. Future studies should focus on the several aspects of CEA presented in patients with appendiceal adenocarcinoma. This could provide treatments for patients with colorectal adenocarcinoma by preventing the development of liver metastases.
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Adenocarcinoma , Neoplasias del Apéndice , Neoplasias Colorrectales , Neoplasias Hepáticas , Adenocarcinoma/patología , Antígeno Carcinoembrionario , Neoplasias Colorrectales/patología , Humanos , Neoplasias Hepáticas/secundarioRESUMEN
For many avian species, spatial migration patterns remain largely undescribed, especially across hemispheric extents. Recent advancements in tracking technologies and high-resolution species distribution models (i.e., eBird Status and Trends products) provide new insights into migratory bird movements and offer a promising opportunity for integrating independent data sources to describe avian migration. Here, we present a three-stage modeling framework for estimating spatial patterns of avian migration. First, we integrate tracking and band re-encounter data to quantify migratory connectivity, defined as the relative proportions of individuals migrating between breeding and nonbreeding regions. Next, we use estimated connectivity proportions along with eBird occurrence probabilities to produce probabilistic least-cost path (LCP) indices. In a final step, we use generalized additive mixed models (GAMMs) both to evaluate the ability of LCP indices to accurately predict (i.e., as a covariate) observed locations derived from tracking and band re-encounter data sets versus pseudo-absence locations during migratory periods and to create a fully integrated (i.e., eBird occurrence, LCP, and tracking/band re-encounter data) spatial prediction index for mapping species-specific seasonal migrations. To illustrate this approach, we apply this framework to describe seasonal migrations of 12 bird species across the Western Hemisphere during pre- and postbreeding migratory periods (i.e., spring and fall, respectively). We found that including LCP indices with eBird occurrence in GAMMs generally improved the ability to accurately predict observed migratory locations compared to models with eBird occurrence alone. Using three performance metrics, the eBird + LCP model demonstrated equivalent or superior fit relative to the eBird-only model for 22 of 24 species-season GAMMs. In particular, the integrated index filled in spatial gaps for species with over-water movements and those that migrated over land where there were few eBird sightings and, thus, low predictive ability of eBird occurrence probabilities (e.g., Amazonian rainforest in South America). This methodology of combining individual-based seasonal movement data with temporally dynamic species distribution models provides a comprehensive approach to integrating multiple data types to describe broad-scale spatial patterns of animal movement. Further development and customization of this approach will continue to advance knowledge about the full annual cycle and conservation of migratory birds.
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Migración Animal , Aves , Animales , Estaciones del Año , América del SurRESUMEN
[This corrects the article DOI: 10.3389/fimmu.2020.00053.].
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Movement by animals to obtain resources and avoid predation often depends on natural cycles, and human alteration of the landscape may disrupt or enhance the utility of different habitats or resources to animals through the phases of these cycles. We studied habitat selection by GPS/accelerometer-tagged great egrets (Ardea alba) foraging in areas with shellfish aquaculture infrastructure and adjacent natural wetlands, while accounting for tide-based changes in water depth. We used integrated step selection analysis to test the prediction that egrets would express stronger selection for natural wetlands (eelgrass, tidal marsh, and other tidal wetlands) than for shellfish aquaculture areas. We also evaluated differences in foraging behavior among shellfish aquaculture areas and natural wetlands by comparing speed travelled (estimated from distance between GPS locations) and energy expended (Overall Dynamic Body Acceleration) while foraging. We found evidence for stronger overall habitat selection for eelgrass than for shellfish aquaculture areas, with results conditional on water depth: egrets used shellfish aquaculture areas, but only within a much narrower range of water depths than they used eelgrass and other natural wetlands. We found only slight differences in our metrics of foraging behavior among shellfish aquaculture areas and natural wetlands. Our results suggest that although great egrets appear to perceive or experience shellfish aquaculture areas as suitable foraging habitat during some conditions, those areas provide less foraging opportunity throughout tidal cycles than natural wetlands. Thus, expanding the footprint of shellfish aquaculture into additional intertidal areas may reduce foraging opportunities for great egrets across the range of tidal cycles. Over longer time scales, the ways in which natural wetlands and shellfish aquaculture areas adapt to rising sea levels (either through passive processes or active management) may change the ratios of these wetland types and consequently change the overall value of Tomales Bay to foraging great egrets.
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Acuicultura/métodos , Aves/fisiología , Ecosistema , Conducta Alimentaria , Humedales , Aceleración , Acelerometría , Animales , Conservación de los Recursos Naturales , Estuarios , Geografía , Conducta Predatoria , Análisis de Regresión , Elevación del Nivel del Mar , MariscosRESUMEN
Conservation of migratory species requires anticipating the potential impacts of extreme climatic events, such as extreme drought. During drought, reduced habitat availability for shorebirds creates the potential for changes in their abundance and distribution, in part because many species are highly mobile and rely on networks of interior and coastal habitats. Understanding how shorebirds responded to a recent drought cycle that peaked from 2013 to 2015 in central California, USA, will help optimize management of wetlands and fresh water for wildlife. In the Central Valley, a vast interior region that is characterized by a mosaic of wetlands and agricultural lands, we found 22% and 29% decreases in the annual abundance of shorebirds during periods of 3-year drought (2013-2015) and 2-year extreme drought (2014-2015), respectively, when compared to non-drought years. Lower abundance of shorebirds coincided with significant decreases in the mean proportion flooded of survey units (7% and 9%, respectively) that were reliant on fresh water. Drought was associated with lower abundance within both the interior Central Valley and coastal San Francisco Bay for greater and lesser yellowlegs (Tringa melanoleuca and T. flavipes) and long- and short-billed dowitchers (Limnodromus scolopaceus and L. griseus). Only dunlins (Calidris alpina) had patterns of abundance that suggested substantial shifts in distribution between the Central Valley and coastal regions of San Francisco Bay and Point Reyes. Our results indicate that drought has the potential to reduce, at least temporally, shorebird populations and flooded habitat in the Central Valley, and the ability to respond to drought by taking advantage of nearby coastal habitats may limit the long-term effects of drought on some species. Successful conservation strategies must balance the impacts of reduced habitat availability at interior sites with the ability of some migratory shorebirds to adapt rapidly to shifting distributions of resources.
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Charadriiformes/fisiología , Conservación de los Recursos Naturales/métodos , Sequías , Migración Animal , Animales , California , Charadriiformes/crecimiento & desarrollo , Estaciones del Año , HumedalesRESUMEN
Persistent neutrophilic inflammation is a hallmark of cystic fibrosis (CF). However, the mechanisms underlying this outstanding pathology remain incompletely understood. Here, we report that CFTR in myeloid immune cells plays a pivotal role in control of neutrophilic inflammation. Myeloid CFTR-Knockout (Mye-Cftr-/-) mice and congenic wild-type (WT) mice were challenged peritoneally with zymosan particles at different doses, creating aseptic peritonitis with varied severity. A high-dose challenge resulted in significantly higher mortality in Mye-Cftr-/- mice, indicating an intrinsic defect in host control of inflammation in mice whose myeloid cells lack CF. The low-dose challenge demonstrated an impaired resolution of inflammation in Mye-Cftr-/- mice, reflected by a significant overproduction of proinflammatory cytokines, including neutrophil chemokines MIP-2 and KC, and sustained accumulation of neutrophils. Tracing neutrophil mobilization in vivo demonstrated that myeloid CF mice recruited significantly more neutrophils than did WT mice. Pulmonary challenge with zymosan elicited exuberant inflammation in the lung and recapitulated the findings from peritoneal challenge. To determine the major type of cell that was primarily responsible for the over-recruitment of neutrophils, we purified and cultured ex vivo zymosan-elicited peritoneal neutrophils and macrophages. The CF neutrophils produced significantly more MIP-2 than did the WT counterparts, and peripheral blood neutrophils isolated from myeloid CF mice also produced significantly more MIP-2 after zymosan stimulation in vitro. These data altogether suggest that CFTR dysfunction in myeloid immune cells, especially neutrophils, leads to hyperinflammation and excessive neutrophil mobilization in the absence of infection. Thus, dysregulated inflammation secondary to abnormal or absent CFTR in myeloid cells may underlie the clinically observed neutrophilic inflammation in CF.
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Regulador de Conductancia de Transmembrana de Fibrosis Quística/deficiencia , Fibrosis Quística/inmunología , Macrófagos Peritoneales/inmunología , Neutrófilos/inmunología , Animales , Fibrosis Quística/patología , Regulador de Conductancia de Transmembrana de Fibrosis Quística/inmunología , Inflamación/inducido químicamente , Inflamación/genética , Inflamación/inmunología , Inflamación/patología , Mutación con Pérdida de Función , Macrófagos Peritoneales/patología , Ratones , Ratones Mutantes , Neutrófilos/patología , Zimosan/toxicidadRESUMEN
BACKGROUND: Ischaemic mitral regurgitation (IMR) carries significant morbidity and mortality. Surgical management includes coronary artery bypass surgery alone or concomitant with mitral valve repair or replacement. There is ongoing debate regarding the appropriate approach to the mitral valve in relation to long-term outcomes. This review examines our early and late follow-up, with operative and echocardiographic outcomes for mitral valve repair and mitral replacement for chronic IMR. METHODS: A retrospective review was performed on prospectively collected data of 119 consecutive patients who either underwent mitral repair (n=101) or mitral replacement (n=18) for chronic IMR at Prince Henry and The Prince of Wales hospitals in Sydney between 1999-2016. All patients had pre and postoperative transthoracic echocardiograms. Follow-up echocardiographic data was obtained from the most recent clinical appointment. Follow-up mortality outcomes were obtained with ethics approval from the Australian National Death Index (NDI). RESULTS: There was no statistical difference between cardiopulmonary bypass (CPB) time, cross-clamp time, time spent in intensive care unit (ICU) and time to discharge between cohorts. The replacement cohort was noted to have higher preoperative pulmonary artery (PA) pressures and a higher severity of IMR. Seven (7) deaths were in the mitral valve (MV) repair group within 30 days (6.9%) and three deaths in the MV replacement group within 30 days (16.7%). Echocardiographic follow-up was complete in 78% of the MV repair cohort at an average of 4.06±2.66 years, and 73% complete in the MV replacement cohort at an average of 6.09±4.3 years. Three (3) patients had prior MV repair before MV replacement early at days zero and 17, and late at 8 years respectively. Follow-up echocardiography showed mitral regurgitation (MR) in the mitral valve repair cohort as ≤ mild in 83.5% and ≤ trivial in 35.6%. In the MV replacement cohort MR ≤ mild in 100% and ≤ trivial in 82% with no moderate or severe MR. Preoperative tricuspid regurgitation (TR) and a flexible annuloplasty were predictive of an MR grade > mild in the repair cohort at discharge. Five-year (5-year) survival for the repair cohort was 85% with a mean follow-up time of 7.1±3.83 years. For the replacement cohort, five-year survival was 77.8% with a mean follow-up time of 5.35±1.54 years. CONCLUSIONS: Mitral valve repair and replacement for chronic IMR has acceptable mortality, reintervention rates and excellent postoperative echocardiographic degrees of IMR in this cohort. Further evaluation is required into quality of life post intervention for IMR and of preoperative predictive factors of significant MR postoperatively to help guide the appropriate choice of treatment. The presence of preoperative tricuspid regurgitation of moderate grade or higher, and the use of a flexible annuloplasty may indicate patients more likely to have a higher grade of MR at follow-up following mitral valve repair in patients with IMR.
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Anuloplastia de la Válvula Mitral/métodos , Insuficiencia de la Válvula Mitral/cirugía , Válvula Mitral/diagnóstico por imagen , Isquemia Miocárdica/complicaciones , Calidad de Vida , Anciano , Ecocardiografía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Válvula Mitral/cirugía , Insuficiencia de la Válvula Mitral/diagnóstico , Insuficiencia de la Válvula Mitral/etiología , Isquemia Miocárdica/diagnóstico , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
PURPOSE: We report our single-institution stereotactic body radiation therapy (SBRT) experience on stage I renal cancer with prospectively collected toxicity and efficacy data. METHODS AND MATERIALS: A total of 21 patients with solitary renal tumors, including 14 surgical candidates who refused surgery (66%), were treated with SBRT. Histologic confirmation was obtained on all patients before treatment; 2 had transitional cell carcinoma and 19 had renal cell carcinoma. The median age was 71 years (range, 58-88). Nearly all patients received 48 Gy in 3 fractions. RESULTS: The median follow-up was 78 months (range, 5-107). At 5 years post treatment, the local tumor control rate was 100%. Tumor size decreased by a median value of 5.3% at 1 year post treatment, 15.6% at 2 years post treatment, and 15.4% at 5 years post treatment. Glomerular filtration rate had decreased by a median value of 1.5% at 1 year post treatment, 7.0% at 2 years post treatment, and 14.2% at 5 years post treatment. Three patients experienced grade 1 toxicity; no other treatment-related adverse effects were reported. CONCLUSIONS: SBRT is a promising noninvasive treatment in the management of primary renal cell carcinoma, with evolving clinical evidence demonstrating encouraging results with respect to local control and toxicity.
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Alcohol differentially affects human health, depending on the pattern of exposure. Moderate intake provides beneficial mood modulation and an anti-inflammatory effect, while excessive consumption leads to immunosuppression and various alcohol use disorders. The mechanism underlying this bi-phasic action mode of alcohol has not been clearly defined. Our previous publication demonstrated that ethanol, in the absence of glucocorticoids (GCs), induces expression of Glucocorticoid-Induced Leucine Zipper (GILZ), a key molecule that transduces GC anti-inflammatory effect through a non-canonical activation of glucocorticoid receptor (1). Here we report that similar short-chain alcohols, such as ethanol, propanol and isopropanol, share the same property of upregulating GILZ gene expression, and blunt cell inflammatory response in vitro. When mice were exposed to these alcohols, GILZ gene expression in immune cells was augmented in a dose-dependent manner. Monocytes and neutrophils were most affected. The short-chain alcohols suppressed host inflammatory response to lipopolysaccharide (LPS) and significantly reduced LPS-induced mortality. Intriguingly, propanol and isopropanol displayed more potent protection than ethanol at the same dose. Inhibition of ethanol metabolism enhanced the ethanol protective effect, suggesting that it is ethanol, not its derivatives or metabolites, that induces immune suppression. Taken together, short-chain alcohols per se upregulate GILZ gene expression and provide immune protection against LPS toxicity, suggesting a potential measure to counter LPS septic shock in a resource limited situation.
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Alcoholes/farmacología , Choque Séptico/inmunología , Factores de Transcripción/biosíntesis , Animales , Células Cultivadas , Citocinas/inmunología , Femenino , Expresión Génica/efectos de los fármacos , Glucocorticoides/metabolismo , Humanos , Inmunidad/efectos de los fármacos , Lipopolisacáridos/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Monocitos/efectos de los fármacos , Choque Séptico/inducido químicamente , Choque Séptico/tratamiento farmacológico , Factores de Transcripción/genética , Factores de Transcripción/inmunología , Regulación hacia Arriba/efectos de los fármacosRESUMEN
Age variation in reproductive performance is well-documented but the mechanisms underlying this variation remain unclear. Foraging efficiency is likely to be a key source of demographic variation as it determines the amount of energy that can be invested in fitness-related activities. Evidence of age-related changes in the foraging efficiency of adult seabirds is scarce and inconsistent. We investigated the effects of age on the foraging efficiency of breeding Adélie penguins, a relatively short-lived seabird species, in order to gain a broader perspective on the processes driving variation in ageing rates. We found support for a positive effect of age, either linear or levelling off at old ages, on both our proxies for daily catch rate and catch per unit effort. Across all age classes, males were more performant foragers than females. We found no strong evidence for differing ageing patterns between sexes or individual quality levels, and no evidence for senescence. We infer that continuous individual improvement could be responsible for a larger amount of the variation in foraging efficiency with age at our study site, compared with selective disappearance of underperforming phenotypes. The different results reported by other studies highlight the need to conduct longitudinal studies across a range of species in different environments.
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Conducta Predatoria , Spheniscidae/fisiología , Factores de Edad , Envejecimiento , Animales , Femenino , Masculino , Factores SexualesRESUMEN
Cystic fibrosis (CF), one of the most common genetic disorders, is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. In spite of significant improvement in patient life expectancy, the disease remains lethal and incurable. Clinically, CF lung disease claims the most morbidity and mortality, characterized by chronic bacterial infection, persistent neutrophilic inflammation, and purulent small airway obstruction. Although all these manifestations are highly associated with neutrophils, the actual role of this phagocyte in the disease pathogenesis has not been fully appreciated. One of the major obstacles impeding such progress is the lack of CF neutrophil cell lines. Taking advantage of the new CRISPR/Cas9 gene-editing technology, we have generated a homozygous ΔF508-CF promyelocytic cell line from HL-60 cells, from which unlimited CF neutrophil cells can be differentiated. The derived cells showed defective CFTR presentation, deficient phagosomal hypochlorous acid (HOCl) production, and compromised microbial killing. Such a phenotype recapitulates that of primary neutrophils from CF patients. Thus, the established human CF promyelocytic cell line should be a useful tool for future CF basic research and drug screening.
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Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Fibrosis Quística/genética , ADN/genética , Células Precursoras de Granulocitos/patología , Terapia Molecular Dirigida/métodos , Mutación , Apoptosis , Línea Celular , Fibrosis Quística/tratamiento farmacológico , Fibrosis Quística/patología , Análisis Mutacional de ADN , Evaluación Preclínica de Medicamentos/métodos , Células Precursoras de Granulocitos/metabolismo , Humanos , FenotipoRESUMEN
Kif5A is a neuronally-enriched isoform of the Kinesin-1 family of cellular transport motors. 23 separate mutations in the motor domain of Kif5A have been identified in patients with the complicated form of hereditary spastic paraplegia (HSP). We performed in vitro assays on dimeric recombinant Kif5A with HSP-causing mutations in the Switch I domain, which participates in the coordination and hydrolysis of ATP by kinesin. We observed a variety of significantly reduced catalytic and mechanical activities as a result of each mutation, with the shared phenotype from each that motility was significantly reduced. Substitution of Mn2+ for Mg2+ in our reaction buffers provides a dose-dependent rescue in both the catalytic and ensemble mechanical properties of the S203C mutant. This work provides mechanistic insight into the cause of HSP in patients with these mutations and points to future experiments to further dissect the root cause of this disease.
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Predisposición Genética a la Enfermedad/genética , Cinesinas/genética , Mutación , Paraplejía Espástica Hereditaria/genética , Adenosina Trifosfato/metabolismo , Sitios de Unión/genética , Unión Competitiva , Biocatálisis/efectos de los fármacos , Humanos , Hidrólisis , Cinesinas/química , Cinesinas/metabolismo , Magnesio/metabolismo , Magnesio/farmacología , Manganeso/metabolismo , Manganeso/farmacología , Microtúbulos/química , Microtúbulos/metabolismo , Simulación de Dinámica Molecular , Unión Proteica , Multimerización de Proteína , Estructura Terciaria de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Paraplejía Espástica Hereditaria/enzimología , Imagen de Lapso de Tiempo/métodosRESUMEN
Acute alcohol exposure suppresses cell inflammatory response. The underlying mechanism has not been fully defined. Here we report that alcohol was able to activate glucocorticoid receptor (GR) signaling in the absence of glucocorticoids (GCs) and upregulated glucocorticoid-induced leucine zipper (gilz), a prominent GC-responsive gene. Such a non-canonical activation of GR was not blocked by mifepristone, a potent GC competitor. The proximal promoter of gilz, encompassing five GC-responsive elements (GREs), was incorporated and tested in a luciferase reporter system. Deletion and/or mutation of the GREs abrogated the promoter responsiveness to alcohol. Thus, the GR-GRE interaction transduced the alcohol action on gilz. Alcohol induced GR nuclear translocation, which was enhanced by the alcohol dehydrogenase inhibitor fomepizole, suggesting that it was alcohol, not its metabolites, that engendered the effect. Gel mobility shift assay showed that unliganded GR was able to bind GREs and such interaction withstood clinically relevant levels of alcohol. GR knockout via CRISPR/Cas9 gene targeting or GILZ depletion via small RNA interference diminished alcohol suppression of cell inflammatory response to LPS. Thus, a previously unrecognized, non-canonical GR activation of gilz is involved in alcohol modulation of cell immune response.
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Temporary abdominal closure (TAC) techniques are routinely used in the open abdomen. Ideally, they should prevent evisceration, aid in removal of unwanted fluid from the peritoneal cavity, facilitate in achieving safe definitive fascial closure, as well as prevent the development of intra-abdominal complications. TAC techniques used in the open abdomen were compared with negative pressure wound therapy (NPWT) to identify which was superior. A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines involving Medline, Excerpta Medica, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, and