20 research outputs found

    Targeting PFKFB3 radiosensitizes cancer cells and suppresses homologous recombination

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    The glycolytic PFKFB3 enzyme is widely overexpressed in cancer cells and an emerging anti-cancer target. Here, we identify PFKFB3 as a critical factor in homologous recombination (HR) repair of DNA double-strand breaks. PFKFB3 rapidly relocates into ionizing radiation (IR)-induced nuclear foci in an MRN-ATM-γH2AX-MDC1-dependent manner and co-localizes with DNA damage and HR repair proteins. PFKFB3 relocalization is critical for recruitment of HR proteins, HR activity, and cell survival upon IR. We develop KAN0438757, a small molecule inhibitor that potently targets PFKFB3. Pharmacological PFKFB3 inhibition impairs recruitment of ribonucleotide reductase M2 and deoxynucleotide incorporation upon DNA repair, and reduces dNTP levels. Importantly, KAN0438757 induces radiosensitization in transformed cells while leaving non-transformed cells unaffected. In summary, we identify a key role for PFKFB3 enzymatic activity in HR repair and present KAN0438757, a selective PFKFB3 inhibitor that could potentially be used as a strategy for the treatment of cancer

    APOE ɛ4 exacerbates age-dependent deficits in cortical microstructure

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    The apolipoprotein E ɛ4 allele is the primary genetic risk factor for the sporadic type of Alzheimer’s disease. However, the mechanisms by which apolipoprotein E ɛ4 are associated with neurodegeneration are still poorly understood. We applied the Neurite Orientation Dispersion Model to characterize the effects of apolipoprotein ɛ4 and its interactions with age and education on cortical microstructure in cognitively normal individuals. Data from 1954 participants were included from the PREVENT-Dementia and ALFA (ALzheimer and FAmilies) studies (mean age = 57, 1197 non-carriers and 757 apolipoprotein E ɛ4 carriers). Structural MRI datasets were processed with FreeSurfer v7.2. The Microstructure Diffusion Toolbox was used to derive Orientation Dispersion Index maps from diffusion MRI datasets. Primary analyses were focused on (i) the main effects of apolipoprotein E ɛ4, and (ii) the interactions of apolipoprotein E ɛ4 with age and education on lobar and vertex-wise Orientation Dispersion Index and implemented using Permutation Analysis of Linear Models. There were apolipoprotein E ɛ4 × age interactions in the temporo-parietal and frontal lobes, indicating steeper age-dependent Orientation Dispersion Index changes in apolipoprotein E ɛ4 carriers. Steeper age-related Orientation Dispersion Index declines were observed among apolipoprotein E ɛ4 carriers with lower years of education. We demonstrated that apolipoprotein E ɛ4 worsened age-related Orientation Dispersion Index decreases in brain regions typically associated with atrophy patterns of Alzheimer’s disease. This finding also suggests that apolipoprotein E ɛ4 may hasten the onset age of dementia by accelerating age-dependent reductions in cortical Orientation Dispersion Index

    Phenotypic diversity of Greek dill (Anethum graveolens L.) landraces

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    Dill has multiple culinary and medicinal purposes and the use of their landraces into a plant breeding program, requires the analysis of their phenotypic diversity. In this study, 33 Greek dill landraces collected from diverse areas were evaluated using traits based on UPOV descriptor list. Phenotypic diversity was assessed using Shannon-Weaver diversity index (H΄) and non-linear principal component analysis. Grouping of landraces was further performed through hierarchical cluster analysis. The H' index ranged from 0.32 (stem waxiness) to 0.98 (density of foliage) with a mean value of 0.68 indicating a high level of phenotypic diversity. High H' values were recorded for the foliage width, stem color and anthocyanin coloration. Multivariate analysis revealed three common genetic groups: 1) North mainland Greece, 2) Aegean islands and 3) Central mainland Greece. The landraces’ heterogeneity was attributed to various traits linked to specific geographic origin, such as early time of flowering and high stem waxiness allied with the landraces originated from the Aegean islands. Greek dill landraces revealed useful variation on yield component traits related to fresh herb weight and to seed production, such as high number of leaves/plant and large diameter of main umbel that can be promptly exploited in breeding programs

    Hydroxamic Acids Constitute a Novel Class of Autotaxin Inhibitors that Exhibit in Vivo Efficacy in a Pulmonary Fibrosis Model

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    Autotaxin (ATX) catalyzes the hydrolysis of lysophosphatidylcholine (LPC) generating the lipid mediator lysophosphatidic acid (LPA). Both ATX and LPA are involved in various pathological inflammatory conditions, including fibrosis and cancer, and have attracted great interest as medicinal targets over the past decade. Thus, the development of novel potent ATX inhibitors is of great importance. We have developed a novel class of ATX inhibitors containing the zinc binding functionality of hydroxamic acid. Such novel hydroxamic acids that incorporate a non-natural δ-amino acid residue exhibit high in vitro inhibitory potency over ATX (IC 50 values 50-60 nM). Inhibitor 32, based on δ-norleucine, was tested for its efficacy in a mouse model of pulmonary inflammation and fibrosis induced by bleomycin and exhibited promising efficacy. The novel hydroxamic ATX inhibitors provide excellent tools for the study of the role of the enzyme and could contribute to the development of novel therapeutic agents for the treatment of fibrosis and other chronic inflammatory diseases. © 2018 American Chemical Society

    Illness perceptions of people with long-term conditions are associated with frequent use of the emergency department independent of mental illness and somatic symptom burden

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    Objective: To determine whether illness perceptions of patients with long-term conditions (LTCs) are associated with urgent healthcare use and whether this association is independent from mental illness and somatic symptom burden. Methods: Illness perceptions (B-IPQ) and somatic symptom severity (PHQ-15) were assessed in 304 patients with diabetes, rheumatological disorders and COPD attending an Accident and Emergency Department (AED) in Greece over a one year period. The presence of mental illness was determined by the Mini International Neuropsychiatric Interview. A Generalized Linear Model (Negative Binomial) regression was used to determine the associations of illness perceptions with AED use after adjusting for mental illness, somatic symptom severity, disease parameters and demographics. Results: Eighty-six patients (28.3%) reported at least one visit to the AED during the previous year and 75 (24.7%) twice or more. 124 patients (40.8%) had some form of mental disorder with 85 (28.0%) meeting criteria for major depressive disorder. The degree to which the patients had an understanding of their illness (illness comprehensibility) (p < 0.01) along with younger age (p < 0.05), additional comorbidities (p < 0.05) and greater somatic symptom burden (p < 0.001) was strongly associated with AED use; AED visits were expected to be reduced by 9.1% for each unit increase in illness comprehensibility. Conclusions: The way people perceive their illness influences urgent healthcare seeking behavior independent of somatic symptom burden. This finding indicates that information provision may prove effective in reducing urgent healthcare use and encourage the design of psycho-educational interventions targeting disease-related cognitions in an attempt to prevent unnecessary healthcare utilization

    Illness perceptions of people with long-term conditions are associated with frequent use of the emergency department independent of mental illness and somatic symptom burden

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    Objective: To determine whether illness perceptions of patients with long-term conditions (LTCs) are associated with urgent healthcare use and whether this association is independent from mental illness and somatic symptom burden. Methods: Illness perceptions (B-IPQ) and somatic symptom severity (PHQ-15) were assessed in 304 patients with diabetes, rheumatological disorders and COPD attending an Accident and Emergency Department (AED) in Greece over a one year period. The presence of mental illness was determined by the Mini International Neuropsychiatric Interview. A Generalized Linear Model (Negative Binomial) regression was used to determine the associations of illness perceptions with AED use after adjusting for mental illness, somatic symptom severity, disease parameters and demographics. Results: Eighty-six patients (28.3%) reported at least one visit to the AED during the previous year and 75 (24.7%) twice or more. 124 patients (40.8%) had some form of mental disorder with 85 (28.0%) meeting criteria for major depressive disorder. The degree to which the patients had an understanding of their illness (illness comprehensibility) (p < 0.01) along with younger age (p < 0.05), additional comorbidities (p < 0.05) and greater somatic symptom burden (p < 0.001) was strongly associated with AED use; AED visits were expected to be reduced by 9.1% for each unit increase in illness comprehensibility. Conclusions: The way people perceive their illness influences urgent healthcare seeking behavior independent of somatic symptom burden. This finding indicates that information provision may prove effective in reducing urgent healthcare use and encourage the design of psycho-educational interventions targeting disease-related cognitions in an attempt to prevent unnecessary healthcare utilization

    Metformin protects against infection-induced myocardial dysfunction

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    Background and Purpose Metformin administration is associated with myocardial protection during ischemia and/or reperfusion, possibly via inhibition of inflammatory responses in the heart. Exposure to pathogens, in addition to the activation of the immune system and the associated metabolic dysfunction, often results in compromised myocardial function. We examined whether metformin administration could maintain the normal myocardial function in experimental moderate Gram negative infection, induced by lipopolysaccharide (LPS) administration. Experimental Approach 129xC57BL/6 mice were divided into control groups that received either vehicle or a single intraperitoneal (i.p.) injection of low dose LPS (5 mg/kg body wt), and metformin treated groups that received either daily metformin (4 mg/kg/animal) i.p. injections for five days prior to LPS administration [Experiment 1], or a single metformin injection following same dose of LPS [Experiment 2]. Key Results LPS alone caused cardiac dysfunction, as confirmed by echocardiography, whereas metformin administration, either before or after LPS, rescued myocardial function. LPS caused marked reduction of the cardiac metabolism-related genes tested, including Prkaa2, Cpt1b, Ppargc1a and Ppargc1b; reduction of fatty acid oxidation, as reflected by the regulation of Ppara, Acaca and Acacb; increased glucose transport, as shown by Slc2a4 levels; reduction of ATP synthesis; significant increase of inflammatory markers, in particular IL6; and reduction of autophagy. Pretreatment with metformin normalized the levels of all these factors. Conclusions and Implications We show for the first time that metformin protects the myocardium from LPS-associated myocardial dysfunction mainly by supporting its metabolic activity and allowing efficient energy utilization. Metformin can be a potential cardioprotective agent in individuals susceptible to exposure to pathogens. © 2016 Elsevier Inc

    A role for bronchial epithelial autotaxin in ventilator-induced lung injury

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    Background The pathophysiology of acute respiratory distress syndrome (ARDS) may eventually result in heterogeneous lung collapse and edema-flooded airways, predisposing the lung to progressive tissue damage known as ventilator-induced lung injury (VILI). Autotaxin (ATX; ENPP2), the enzyme largely responsible for extracellular lysophosphatidic acid (LPA) production, has been suggested to play a pathogenic role in, among others, pulmonary inflammation and fibrosis. Methods C57BL/6 mice were subjected to low and high tidal volume mechanical ventilation using a small animal ventilator: respiratory mechanics were evaluated, and plasma and bronchoalveolar lavage fluid (BALF) samples were obtained. Total protein concentration was determined, and lung histopathology was further performed Results Injurious ventilation resulted in increased BALF levels of ATX. Genetic deletion of ATX from bronchial epithelial cells attenuated VILI-induced pulmonary edema. Conclusion ATX participates in VILI pathogenesis

    Vitamin D prevents experimental lung fibrosis and predicts survival in patients with idiopathic pulmonary fibrosis

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    Background: Vitamin D (VitD) is a steroid hormone with cytoprotective and anti-inflammatory properties. Epidemiological studies have suggested a link between VitD deficiency and risk of development of chronic lung diseases. Its role in lung fibrosis is largely unknown. The aim of our study was to investigate the role of VitD in experimental and human lung fibrosis. Methods: VitD (25-OH-D3, 2 μg/kg) was orally administered from day 3-day 13 following bleomycin-challenge, in 8–10 weeks-old C57/BL6 mice. Mouse Lung Fibroblasts (MLFs) were pre-treated with VitD (2 μM for 24 h) and then stimulated with TGFB1 (10 ng/ml). Serum samples from 93 patients with IPF and other forms of interstitial lung diseases (ILDs) were prospectively collected for VitD measurement. Results: VitD administration prevented bleomycin-induced lung fibrosis, as assessed by reductions in hydroxyproline levels, mRNA levels of col1a1, col3a1 and a-SMA (1.4-, 3.1-, 2.25-, 2.5-fold, respectively) and Masson Trichrome staining compared to the untreated group and these changes were associated with restoration of the bleomycin-induced downregulation of vitamin D-receptor (Vdr) mRNA levels. Pre-treatment with VitD reduced the responsiveness of MLFs to pro-fibrotic stimuli, as indicated by significant decreases of col1a1, col3a1 and a-SMA (3.6-, 4.1- and 2.7-fold, respectively).These changes were associated with restoration of the TGFB1-induced downregulation of vitamin D-receptor (VDR) mRNA levels. VitD treatment deactivated TGFB1-induced Smad3 phosphorylation. Patients with IPF and other forms of ILDs displayed deficient VitD serum concentrations (mean VitD = 18.76 ± 8.36 vs. 18.54 ± 8.39 ng/ml, respectively, p = 0.9). VitD deficiency was correlated with baseline FVC%predicted (r = 0.47, p &lt; 0.0001), DLCO%predicted (r = 0.6, p &lt; 0.0001), GAP score (r = −0.4, p &lt; 0.0001) and all-cause mortality in patients with IPF (HR: 3.7, p = 0.001). Conclusions: VitD could serve as a prognosticator and potential therapeutic target in patients with IPF. Further studies are sorely needed. © 2019 Elsevier Lt
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