17 research outputs found

    Nuclear factor ÎșB-inducing kinase activation as a mechanism of pancreatic ÎČ cell failure in obesity

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    The nuclear factor ÎșB (NF-ÎșB) pathway is a master regulator of inflammatory processes and is implicated in insulin resistance and pancreatic ÎČ cell dysfunction in the metabolic syndrome. Whereas canonical NF-ÎșB signaling is well studied, there is little information on the divergent noncanonical NF-ÎșB pathway in the context of pancreatic islet dysfunction. Here, we demonstrate that pharmacological activation of the noncanonical NF-ÎșB-inducing kinase (NIK) disrupts glucose homeostasis in zebrafish in vivo. We identify NIK as a critical negative regulator of ÎČ cell function, as pharmacological NIK activation results in impaired glucose-stimulated insulin secretion in mouse and human islets. NIK levels are elevated in pancreatic islets isolated from diet-induced obese (DIO) mice, which exhibit increased processing of noncanonical NF-ÎșB components p100 to p52, and accumulation of RelB. TNF and receptor activator of NF-ÎșB ligand (RANKL), two ligands associated with diabetes, induce NIK in islets. Mice with constitutive ÎČ cell-intrinsic NIK activation present impaired insulin secretion with DIO. NIK activation triggers the noncanonical NF-ÎșB transcriptional network to induce genes identified in human type 2 diabetes genome-wide association studies linked to ÎČ cell failure. These studies reveal that NIK contributes a central mechanism for ÎČ cell failure in diet-induced obesity

    Environmental, Dietary, Maternal, and Fetal Predictors of Bulky DNA Adducts in Cord Blood: A European Mother–Child Study (NewGeneris)

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    Background:Bulky DNA adducts reflect genotoxic exposures, have been associated with lower birth weight, and may predict cancer risk.Objective:We selected factors known or hypothesized to affect in utero adduct formation and repair and examined their associations with adduct levels in neonates.Methods:Pregnant women from Greece, Spain, England, Denmark, and Norway were recruited in 2006–2010. Cord blood bulky DNA adduct levels were measured by the 32P-postlabeling technique (n = 511). Diet and maternal characteristics were assessed via questionnaires. Modeled exposures to air pollutants and drinking-water disinfection by-products, mainly trihalomethanes (THMs), were available for a large proportion of the study population.Results:Greek and Spanish neonates had higher adduct levels than the northern European neonates [median, 12.1 (n = 179) vs. 6.8 (n = 332) adducts per 108 nucleotides, p < 0.001]. Residence in southern European countries, higher maternal body mass index, delivery by cesarean section, male infant sex, low maternal intake of fruits rich in vitamin C, high intake of dairy products, and low adherence to healthy diet score were statistically significantly associated with higher adduct levels in adjusted models. Exposure to fine particulate matter and nitrogen dioxide was associated with significantly higher adducts in the Danish subsample only. Overall, the pooled results for THMs in water show no evidence of association with adduct levels; however, there are country-specific differences in results with a suggestion of an association in England.Conclusion:These findings suggest that a combination of factors, including unknown country-specific factors, influence the bulky DNA adduct levels in neonates.Citation:Pedersen M, Mendez MA, Schoket B, Godschalk RW, Espinosa A, Landström A, Villanueva CM, Merlo DF, Fthenou E, Gracia-Lavedan E, van Schooten FJ, Hoek G, Brunborg G, Meltzer HM, Alexander J, Nielsen JK, Sunyer J, Wright J, KovĂĄcs K, de Hoogh K, Gutzkow KB, Hardie LJ, Chatzi L, Knudsen LE, Anna L, Ketzel M, Haugen M, Botsivali M, Nieuwenhuijsen MJ, Cirach M, Toledano MB, Smith RB, Fleming S, Agramunt S, Kyrtopoulos SA, LukĂĄcs V, Kleinjans JC, SegerbĂ€ck D, Kogevinas M. 2015. Environmental, dietary, maternal, and fetal predictors of bulky DNA adducts in cord blood: a European mother–child study (NewGeneris). Environ Health Perspect 123:374–380; http://dx.doi.org/10.1289/ehp.140861

    Prevention and reversal of frailty in heart failure - a systemic review

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    Background: Frailty is prevalent in patients with heart failure (HF) and associated with increased morbidity and mortality. Hence, there has been increased interest in the reversibility of frailty following treatment with medication or surgery. This systematic review aimed to assess the reversibility of frailty in patients with HF before and after surgical interventions aimed at treating the underlying cause of HF. It also aimed to assess the efficacy of cardiac rehabilitation and prehabilitation in reversing or preventing frailty in patients with HF. Methods and Results: Searches of PubMed, MEDLINE and Academic Search Ultimate identified studies with HF patients undergoing interventions to reverse frailty. Titles, abstracts and full texts were screened for eligibility based on the PRISMA guidelines and using predefined inclusion/exclusion criteria in relation to participants, intervention, control, outcome and study design. In total, 14 studies were included: 3 assessed the effect of surgery, 7 assessed the effect of rehabilitation programs, 2 assessed the effect of a prehabilitation program and 2 assessed the effect of program interruptions on HF patients. Conclusions: Overall, it was found that frailty is at least partially reversible and potentially preventable in patients with HF. Interruption of rehabilitation programs resulted in deterioration of the frailty status. Future research should focus on the role of prehabilitation in mitigating frailty prior to surgical intervention

    The spatiotemporal movement of patients in and out of a psychiatric hospital: an observational GPS study

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    Background Movement is a basic component of health. Little is known about the spatiotemporal movement of patients with mental disorders. The aim of this study was to determine how spatiotemporal movement of patients related to their symptoms and wellbeing. Method A total of 106 patients (inpatients (n = 69) and outpatients (n = 37)) treated for a wide range of mental disorders (transdiagnostic sample) carried a GPS-enabled smartphone for one week at the beginning of treatment. Algorithms were applied to establish spatiotemporal clusters and subsequently related to known characteristics of these groups (i.e., at the hospital, at home). Symptomatology, Wellbeing, and Psychological flexibility were also assessed. Results Spatiotemporal patterns of inpatients and outpatients showed differences consistent with predictions (e.g., outpatients showed higher active areas). These patterns were largely unassociated with symptoms (except for agoraphobic symptoms). Greater movement and variety of movement were more predictive of wellbeing, however, in both inpatients and outpatients. Conclusion Measuring spatiotemporal patterns is feasible, predictive of wellbeing, and may be a marker of patient functioning. Ethical issues of collecting GPS data are discussed

    A novel method of microsatellite genotyping-by-sequencing using individual combinatorial barcoding

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    This study examines the potential of next-generation sequencing based 'genotyping-by-sequencing' (GBS) of microsatellite loci for rapid and cost-effective genotyping in large-scale population genetic studies. The recovery of individual genotypes from large sequence pools was achieved by PCR-incorporated combinatorial barcoding using universal primers. Three experimental conditions were employed to explore the possibility of using this approach with existing and novel multiplex marker panels and weighted amplicon mixture. The GBS approach was validated against microsatellite data generated by capillary electrophoresis. GBS allows access to the underlying nucleotide sequences that can reveal homoplasy, even in large datasets and facilitates cross laboratory transfer. GBS of microsatellites, using individual combinatorial barcoding, is potentially faster and cheaper than current microsatellite approaches and offers better and more data

    A novel method of microsatellite genotyping-by-sequencing using individual combinatorial barcoding.

    No full text
    This study examines the potential of next-generation sequencing based 'genotyping-by-sequencing' (GBS) of microsatellite loci for rapid and cost-effective genotyping in large-scale population genetic studies. The recovery of individual genotypes from large sequence pools was achieved by PCR-incorporated combinatorial barcoding using universal primers. Three experimental conditions were employed to explore the possibility of using this approach with existing and novel multiplex marker panels and weighted amplicon mixture. The GBS approach was validated against microsatellite data generated by capillary electrophoresis. GBS allows access to the underlying nucleotide sequences that can reveal homoplasy, even in large datasets and facilitates cross laboratory transfer. GBS of microsatellites, using individual combinatorial barcoding, is potentially faster and cheaper than current microsatellite approaches and offers better and more data..S.V. and R.F. acknowledge funding from the Sea Change Strategy with the support of the Marine Institute and the Marine Research Sub-programme of the National Development Plan 2007–2013, co-financed by the European Regional Development Fund (Grant-Aid Agreement no. PBA/AF/07/004, EIRCOD). J.L.V.-C. acknowledges funding from the Spanish Ministerio de Economía y Competitividad (FPI BES-2010–038494 and EEBB-I-13–06270). G.H. acknowledges funding by the Irish Research Council (IRC) Graduate Research Education Programme (GREP). P.M. and J.C. acknowledge funding from the Beaufort Marine Research Award in Fish Population Genetics funded by the Irish Government under the Sea Change Programme. P.C.C. acknowledges funding from Science Foundation Ireland (SFI 12/IP/1308). E.D.F. acknowledges funding from Irish Research Council (IRC) (Funding Agency Ref no./nGOIPD/2013/320)

    Pdgf-ab and 5-Azacytidine induce conversion of somatic cells into tissue-regenerative multipotent stem cells

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    Current approaches in tissue engineering are geared toward generating tissue-specific stem cells. Given the complexity and heterogeneity of tissues, this approach has its limitations. An alternate approach is to induce terminally differentiated cells to dedifferentiate into multipotent proliferative cells with the capacity to regenerate all components of a damaged tissue, a phenomenon used by salamanders to regenerate limbs. 5-Azacytidine (AZA) is a nucleoside analog that is used to treat preleukemic and leukemic blood disorders. AZA is also known to induce cell plasticity. We hypothesized that AZA-induced cell plasticity occurs via a transient multipotent cell state and that concomitant exposure to a receptive growth factor might result in the expansion of a plastic and proliferative population of cells. To this end, we treated lineagecommitted cells with AZA and screened a number of different growth factors with known activity in mesenchyme-derived tissues. Here, we report that transient treatment with AZA in combination with platelet-derived growth factor-AB converts primary somatic cells into tissue-regenerative multipotent stem (iMS) cells. iMS cells possess a distinct transcriptome, are immunosuppressive, and demonstrate long-term self-renewal, serial clonogenicity, and multigerm layer differentiation potential. Importantly, unlike mesenchymal stem cells, iMS cells contribute directly to in vivo tissue regeneration in a context-dependent manner and, unlike embryonic or pluripotent stem cells, do not form teratomas. Taken together, this vector-free method of generating iMS cells from primary terminally differentiated cells has significant scope for application in tissue regeneration.Link_to_subscribed_fulltex

    Denisovan, modern human and mouse TNFAIP3 alleles tune A20 phosphorylation and immunity

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    Resisting and tolerating microbes are alternative strategies to survive infection, but little is known about the evolutionary mechanisms controlling this balance. Here genomic analyses of anatomically modern humans, extinct Denisovan hominins and mice revealed a TNFAIP3 allelic series with alterations in the encoded immune response inhibitor A20. Each TNFAIP3 allele encoded substitutions at non-catalytic residues of the ubiquitin protease OTU domain that diminished IÎșB kinase-dependent phosphorylation and activation of A20. Two TNFAIP3 alleles encoding A20 proteins with partial phosphorylation deficits seemed to be beneficial by increasing immunity without causing spontaneous inflammatory disease: A20 T108A;I207L, originating in Denisovans and introgressed in modern humans throughout Oceania, and A20 I325N, from an N-ethyl-N-nitrosourea (ENU)-mutagenized mouse strain. By contrast, a rare human TNFAIP3 allele encoding an A20 protein with 95% loss of phosphorylation, C243Y, caused spontaneous inflammatory disease in humans and mice. Analysis of the partial-phosphorylation A20 I325N allele in mice revealed diminished tolerance of bacterial lipopolysaccharide and poxvirus inoculation as tradeoffs for enhanced immunity.</p
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