87 research outputs found
Response of early Toarcian (Early Jurassic) benthic marine faunas from South-Western Europe to temperature-related stressors
Globaler Temperaturanstieg, Ozeanversauerung und Sauerstoffmangel (temperaturbedingte Stressoren), spielen eine wichtige Rolle während Klimawandel. Die kombinierten Auswirkungen wirken sich negativ auf marine Lebensgemeinschaften und Ökosystemen aus und verschärfen die Effekte anderer Stressoren. Es gibt für den aktuellen und vergangenen Erwärmungsphasen Belege für veränderte Artenverteilung, Lebensraumverlust, Artensterben und verminderte physiologische Leistungen von Organismen. Die spezifischen Mechanismen werden diskutiert. Umweltveränderungen in der Erdvergangenheit bieten die Gelegenheit, die Dynamik von Ökosystemkrisen vor, zu untersuchen. Diese Arbeit integriert verschiedenen Disziplinen um unser Verständnis der Rolle temperaturbedingter Stressoren für marine benthische Ökosysteme zu verbessern. Das Toarcian Event (Unterjura) wurde aufgrund seiner geologischen, geochemischen und paläontologischen Überlieferung ausgewählt. Hochaufgelöste quantitative taxonomische, paläoökologische und geochemische Daten von benthischen Makroinvertebraten wurden analysiert. Ziel ist es, die Mechanismen ökologischer Veränderungen unter Temperaturstress zu bewerten, mit Schwerpunkt auf Körpergrößenmuster sowie Veränderungen in der Zusammensetzung und Struktur von Lebensgemeinschaften, und die Rolle von Umweltstressoren als Ursachen der biotischen Krise abzuschätzen. Der Temperaturanstieg führte zu dem Verlust an biologischer Vielfalt und zu der Verringerung der Körpergröße der Organismen vor und während der biotischen Krise. Die Struktur der Gemeinschaften wurde in Bezug auf die taxonomische und ökologische Zusammensetzung neu organisiert. Die Reaktion auf Umweltstress war innerhalb und zwischen den taxonomischen Gruppen unterschiedlich, wobei Brachiopoden stark betroffen waren. Diese Ergebnisse verbessern unser Verständnis der biotischen Reaktionen auf temperaturbedingte Stressoren und können zur Vorhersage Veränderungen Ökosysteme bei den aktuellen Erwärmungstrends beitragen.Global warming, oceanic acidification and deoxygenation (temperature-related stressors) play an important role during climate change. The combined impact of these stressors is known to negatively affect marine biota and ecosystems, often exacerbating the impact of other stressors. Under the current and past climate change, there is record of altered species distribution, habitat loss, extinctions and decreased physiological performance of organisms. Despite the increasing evidence, the specific mechanisms through which climate change influences ecological patterns are debated. Past environmental perturbations represent an opportunity to investigate the dynamics of ecosystem and biotic crises across Earth history. This work integrates different disciplines to increase our understanding on the role played by temperature-related stressors on marine benthic biota and ecosystems. The Toarcian Event (Early Jurassic) was chosen for its well-preserved geological, geochemical and palaeontological record. High-resolution quantitative faunal and geochemical data from benthic marine macroinvertebrates were investigated. The aims are to identify and evaluate the mechanisms of faunal and ecological shifts under a temperature-related stressor scenario, with focus on body size patterns and ecosystem change and recovery, and to estimate the role of environmental stressors as proximate causes of the biotic crisis. Temperature increase led to biodiversity loss and reduced body size of organisms during and possibly before the event. Moreover, the structure of marine communities was reorganized in terms of taxonomic and ecological composition. The response to environmental stress was variable within and between taxonomical groups, with brachiopods severely affected. These findings increase our understanding of biotic responses and ecosystem and biodiversity shifts under temperature stress, hopefully contributing to the prediction of ecosystem changes under the current warming scenario
Cross-talk between chronic lymphocytic leukemia (CLL) tumor B cells and mesenchymal stromal cells (MSCs): implications for neoplastic cell survival
Leukemic cells from Chronic Lymphocytic Leukemia (CLL) patients interact with stromal cells of the surrounding microenvironment. Mesenchymal Stromal Cells (MSCs) represent the main population in CLL marrow stroma, which may play a key role for disease support and progression. In this study we evaluated whether MSCs influence in vitro CLL cell survival. MSCs were isolated from the bone marrow of 46 CLL patients and were characterized by flow cytometry analysis. Following co-culture of MSCs and leukemic B cells, we demonstrated that MSCs were able to improve leukemic B cell viability, this latter being differently dependent from the signals coming from MSCs. In addition, we found that the co-culture of MSCs with leukemic B cells induced an increased production of IL-8, CCL4, CCL11, and CXCL10 chemokines.As far as drug resistance is concerned, MSCs counteract the cytotoxic effect of Fludarabine/Cyclophosphamide administration in vivo, whereas they do not protect CLL cells from the apoptosis induced by the kinase inhibitors Bafetinib and Ibrutinib. The evidence that leukemic clones are conditioned by environmental stimuli suggest new putative targets for therapy in CLL patients
Clinical Significance of Apurinic/Apyrimidinic Endodeoxyribonuclease 1 and MicroRNA Axis in Hepatocellular Carcinoma
Background and Aims: Identification of prognostic factors for hepatocellular carcinoma (HCC) opens new perspectives for therapy. Circulating and cellular onco-miRNAs are noncod ing RNAs which can control the expression of genes involved in oncogenesis through post-transcriptional mechanisms. These microRNAs (miRNAs) are considered novel prognostic and pre-dictive factors in HCC. The apurinic/apyrimidinic endodeoxy-ribonuclease 1 (APE1) contributes to the quality control and processing of specific onco-miRNAs and is a negative prognos-tic factor in several tumors. The present work aims to: a) de -fine APE1 prognostic value in HCC; b) identify miRNAs regulat-ed by APE1 and their relative target genes and c) study their prognostic value. Methods: We used The Cancer Genome At-las (commonly known as TCGA) data analysis to evaluate the expression of APE1 in HCC. To identify differentially-expressed miRNAs (DEmiRNAs) upon APE1 depletion through specific small interfering RNA, we used NGS and nanostring approach-es in the JHH-6 HCC tumor cell line. Bioinformatics analy-ses were performed to identify signaling pathways involving APE1-regulated miRNAs. Microarray analysis was performed to identify miRNAs correlating with serum APE1 expression. Results: APE1 is considerably overexpressed in HCC tissues compared to normal liver, according to the TCGA-liver HCC (known as LIHC) dataset. Enrichment analyses showed that APE1-regulated miRNAs are implicated in signaling and metabolic pathways linked to cell proliferation, transformation, and angiogenesis, identifying Cyclin Dependent Kinase 6 and Lyso-somal Associated Membrane Protein 2 as targets. miR-33a-5p, miR-769, and miR-877 are related to lower overall survival in HCC patients. Through array profiling, we identified eight circulating DE-miRNAs associated with APE1 overexpression. A training phase identified positive association between sAPE1 and miR-3180-3p and miR-769. Conclusions: APE1 regulates specific miRNAs having prognostic value in HCC
APE1 controls DICER1 expression in NSCLC through miR-33a and miR-130b
Increasing evidence suggests different, not completely understood roles of microRNA biogenesis in the development and progression of lung cancer. The overexpression of the DNA repair protein apurinic/apyrimidinic endodeoxyribonuclease 1 (APE1) is an important cause of poor chemotherapeutic response in lung cancer and its involvement in onco-miRNAs biogenesis has been recently described. Whether APE1 regulates miRNAs acting as prognostic biomarkers of lung cancer has not been investigated, yet. In this study, we analyzed miRNAs differential expression upon APE1 depletion in the A549 lung cancer cell line using high-throughput methods. We defined a signature of 13 miRNAs that strongly correlate with APE1 expression in human lung cancer: miR-1246, miR-4488, miR-24, miR-183, miR-660, miR-130b, miR-543, miR-200c, miR-376c, miR-218, miR-146a, miR-92b and miR-33a. Functional enrichment analysis of this signature revealed its biological relevance in cancer cell proliferation and survival. We validated DICER1 as a direct functional target of the APE1-regulated miRNA-33a-5p and miR-130b-3p. Importantly, IHC analyses of different human tumors confirmed a negative correlation existing between APE1 and Dicer1 protein levels. DICER1 downregulation represents a prognostic marker of cancer development but the mechanisms at the basis of this phenomenon are still completely unknown. Our findings, suggesting that APE1 modulates DICER1 expression via miR-33a and miR-130b, reveal new mechanistic insights on DICER1 regulation, which are of relevance in lung cancer chemoresistance and cancer invasiveness
In Chronic Lymphocytic Leukemia the JAK2/STAT3 Pathway Is Constitutively Activated and Its Inhibition Leads to CLL Cell Death Unaffected by the Protective Bone Marrow Microenvironment
The bone marrow microenvironment promotes proliferation and drug resistance in chronic lymphocytic leukemia (CLL). Although ibrutinib is active in CLL, it is rarely able to clear leukemic cells protected by bone marrow mesenchymal stromal cells (BMSCs) within the marrow niche. We investigated the modulation of JAK2/STAT3 pathway in CLL by BMSCs and its targeting with AG490 (JAK2 inhibitor) or Stattic (STAT3 inhibitor). B cells collected from controls and CLL patients, were treated with medium alone, ibrutinib, JAK/Signal Transducer and Activator of Transcription (STAT) inhibitors, or both drugs, in the presence of absence of BMSCs. JAK2/STAT3 axis was evaluated by western blotting, flow cytometry, and confocal microscopy. We demonstrated that STAT3 was phosphorylated in Tyr705 in the majority of CLL patients at basal condition, and increased following co-cultures with BMSCs or IL-6. Treatment with AG490, but not Stattic, caused STAT3 and Lyn dephosphorylation, through re-activation of SHP-1, and triggered CLL apoptosis even when leukemic cells were cultured on BMSC layers. Moreover, while BMSCs hamper ibrutinib activity, the combination of ibrutinib+JAK/STAT inhibitors increase ibrutinib-mediated leukemic cell death, bypassing the pro-survival stimuli derived from BMSCs. We herein provide evidence that JAK2/STAT3 signaling might play a key role in the regulation of CLL-BMSC interactions and its inhibition enhances ibrutinib, counteracting the bone marrow niche
Microplastics ingestion in the ephyra stage of Aurelia sp. triggers acute and behavioral responses
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
Malignant carotid body tumors: What we know, what we do, and what we need to achieve. A systematic review of the literature
: Malignant carotid body tumors (MCBT) are rare and diagnosed after detection of nodal or distant metastases. This systematic review (SR) focuses on MCBT initially approached by surgery. Preferred Reporting Items for SR and Meta-Analysis (MA) guided the articles search from 2000 to 2023 on PubMed, Scopus, and Web of Science. Among 3548 papers, 132 (337 patients) were considered for SR; of these, 20 (158 patients) for MA. Malignancy rate was 7.3%, succinate dehydrogenase (SDH) mutation 17%, age at diagnosis between 4th and 6th decades, with a higher prevalence of females. MCBTs were mostly Shamblin III, with nodal and distant metastasis in 79.7% and 44.7%, respectively. Malignancy should be suspected if CBT >4 cm, Shamblin III, painful or otherwise symptomatic, at the extremes of age, bilateral, with multifocal disease, and SDHx mutations. Levels II-III clearance should be performed to exclude nodal metastases and adjuvant treatments considered on a case-by-case basis
Temporal Brain Dynamics of Multiple Object Processing: The Flexibility of Individuation
The ability to process concurrently multiple visual objects is fundamental for a coherent perception of the world. A core component of this ability is the simultaneous individuation of multiple objects. Many studies have addressed the mechanism of object individuation but it remains unknown whether the visual system mandatorily individuates all relevant elements in the visual field, or whether object indexing depends on task demands. We used a neural measure of visual selection, the N2pc component, to evaluate the flexibility of multiple object individuation. In three ERP experiments, participants saw a variable number of target elements among homogenous distracters and performed either an enumeration task (Experiment 1) or a detection task, reporting whether at least one (Experiment 2) or a specified number of target elements (Experiment 3) was present. While in the enumeration task the N2pc response increased as a function of the number of targets, no such modulation was found in Experiment 2, indicating that individuation of multiple targets is not mandatory. However, a modulation of the N2pc similar to the enumeration task was visible in Experiment 3, further highlighting that object individuation is a flexible mechanism that binds indexes to object properties and locations as needed for further object processing
Risk of progression in chronic phase-chronic myeloid leukemia patients eligible for tyrosine kinase inhibitor discontinuation: Final analysis of the TFR-PRO study
Disease progression to accelerated/blast phase (AP/BP) in patients with chronic phase chronic myeloid leukemia (CP-CML) after treatment discontinuation (TD) has never been systematically reported in clinical trials. However, recent reports of several such cases has raised concern. To estimate the risk of AP/BP among TD-eligible patients, we conducted TFR-PRO, a cohort retro-prospective study: 870 CP-CML patients eligible for TD formed a discontinuation cohort (505 patients) and a reference one (365 patients). The primary objective was the time adjusted rate (TAR) of progression in relation to TD. Secondary endpoints included the TAR of molecular relapse, that is, loss of major molecular response (MMR). With a median follow up of 5.5 years and 5188.2 person-years available, no events occurred in the TD cohort. One event of progression was registered 55 months after the end of TD, when the patient was contributing to the reference cohort. The TAR of progression was 0.019/100 person-years (95% CI [0.003-0.138]) in the overall group; 0.0 (95% CI [0-0.163]) in the discontinuation cohort; and 0.030 (95% CI [0.004-0.215]) in the reference cohort. These differences are not statistically significant. Molecular relapses occurred in 172/505 (34.1%) patients after TD, and in 64/365 (17.5%) patients in the reference cohort, p < .0001. Similar rates were observed in TD patients in first, second or third line of treatment. CML progression in patients eligible for TD is rare and not related to TD. Fears about the risk of disease progression among patients attempting TD should be dissipated
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