124 research outputs found

    Statins do not directly inhibit the activity of major epigenetic modifying enzymes

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    The potential anticancer effects of statins—a widely used class of cholesterol loweringdrugs—has generated significant interest, as has the use of epigenetic modifying drugs such asHDAC and DNMT inhibitors. We set out to investigate the effect of statin drugs on epigeneticmodifications in multiple cell lines, including hepatocellular carcinoma, breast carcinoma, leukemicmacrophages, cervical adenocarcinoma, and insulin-secreting cells, as well as liver extracts fromstatin-treated C57B1/6J mice. Cells or cell extracts were treated with statins and with establishedepigenetic modulators, and HDAC, HAT, and DNMT activities were quantified. We also examinedhistone acetylation by immunoblotting. Statins altered neither HDAC nor HAT activity. Accordingly,acetylation of histones H3 and H4 was unchanged with statin treatment. However, statins tended toincrease DNMT activity. These results indicate that direct inhibition of the major classes of epigeneticmodifying enzymes, as previously reported elsewhere, is unlikely to contribute to any anticancereffects of statins. This study concerned global effects on epigenetic enzyme activities and histoneacetylation; whether statins influence epigenetic modifications in certain genomic regions, cannot beruled out and remains to be investigated

    Why place matters in residential care: the mediating role of place attachment in the relation between adolescents’ rights and psychological well-being

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    Little evidence exists on the relationship between rights’ perceptions and well-being outcomes during the adolescence, and particularly in care, as well as on the mediating role of place attachment. Young people in residential care are psychologically and socially vulnerable, showing greater difficulties than their peers do in the family. Youth’s rights fulfilment in residential care may positively affect their psychological functioning together with positive attachments to this place. A sample of 365 adolescents in residential care settings (M = 14.71, SD = 1.81) completed a set of self-reported measures, specifically, the Rights perceptions scale, the Place attachment scale and Scales of psychological well-being. Results revealed significant mediating effects of place attachment (Global scale and subscales of Friends Bonding and Place Dependence) on the relationship between Participation and Protection rights in residential care and Psychological well-being (Positive Relations with others, Personal Growth and Self-Acceptance). The positive role of rights fulfilment in residential care, specifically participation opportunities, as well as the role of youth’s attachment to the care setting are discussed based on previous evidence and theoretical assumptions. A set of practical implications is described.info:eu-repo/semantics/acceptedVersio

    UGT1A1 is a major locus influencing bilirubin levels in African Americans

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    Total serum bilirubin is associated with several clinical outcomes, including cardiovascular disease, diabetes and drug metabolism. We conducted a genome-wide association study in 619 healthy unrelated African Americans in an attempt to replicate reported findings in Europeans and Asians and to identify novel loci influencing total serum bilirubin levels. We analyzed a dense panel of over two million genotyped and imputed SNPs in additive genetic models adjusting for age, sex, and the first two significant principal components from the sample covariance matrix of genotypes. Thirty-nine SNPs spanning a 78 kb region within the UGT1A1 displayed P-values <5 × 10−8. The lowest P-value was 1.7 × 10−22 for SNP rs887829. None of SNPs in the UGT1A1 remained statistically significant in conditional association analyses that adjusted for rs887829. In addition, SNP rs10929302 located in phenobarbital response enhancer module was significantly associated with bilirubin level with a P-value of 1.37 × 10−11; this enhancer module is believed to have a critical role in phenobarbital treatment of hyperbilirubinemia. Interestingly, the lead SNP, rs887829, is in strong linkage disequilibrium (LD) (r2≥0.74) with rs10929302. Taking advantage of the lower LD and shorter haplotypes in African-ancestry populations, we identified rs887829 as a more refined proxy for the causative variant influencing bilirubin levels. Also, we replicated the reported association between variants in SEMA3C and bilirubin levels. In summary, UGT1A1 is a major locus influencing bilirubin levels and the results of this study promise to contribute to understanding of the etiology and treatment of hyperbilirubinaemia in African-ancestry populations

    Beringian Standstill and Spread of Native American Founders

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    Native Americans derive from a small number of Asian founders who likely arrived to the Americas via Beringia. However, additional details about the intial colonization of the Americas remain unclear. To investigate the pioneering phase in the Americas we analyzed a total of 623 complete mtDNAs from the Americas and Asia, including 20 new complete mtDNAs from the Americas and seven from Asia. This sequence data was used to direct high-resolution genotyping from 20 American and 26 Asian populations. Here we describe more genetic diversity within the founder population than was previously reported. The newly resolved phylogenetic structure suggests that ancestors of Native Americans paused when they reached Beringia, during which time New World founder lineages differentiated from their Asian sister-clades. This pause in movement was followed by a swift migration southward that distributed the founder types all the way to South America. The data also suggest more recent bi-directional gene flow between Siberia and the North American Arctic

    Deletion of Genes Implicated in Protecting the Integrity of Male Germ Cells Has Differential Effects on the Incidence of DNA Breaks and Germ Cell Loss

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    Infertility affects approximately 20% of couples in Europe and in 50% of cases the problem lies with the male partner. The impact of damaged DNA originating in the male germ line on infertility is poorly understood but may increase miscarriage. Mouse models allow us to investigate how deficiencies in DNA repair/damage response pathways impact on formation and function of male germ cells. We have investigated mice with deletions of ERCC1 (excision repair cross-complementing gene 1), MSH2 (MutS homolog 2, involved in mismatch repair pathway), and p53 (tumour suppressor gene implicated in elimination of germ cells with DNA damage).We demonstrate for the first time that depletion of ERCC1 or p53 from germ cells results in an increased incidence of unrepaired DNA breaks in pachytene spermatocytes and increased numbers of caspase-3 positive (apoptotic) germ cells. Sertoli cell-only tubules were detected in testes from mice lacking expression of ERCC1 or MSH2 but not p53. The number of sperm recovered from epididymes was significantly reduced in mice lacking testicular ERCC1 and 40% of sperm contained DNA breaks whereas the numbers of sperm were not different to controls in adult Msh2 -/- or p53 -/- mice nor did they have significantly compromised DNA.These data have demonstrated that deletion of Ercc1, Msh2 and p53 can have differential but overlapping affects on germ cell function and sperm production. These findings increase our understanding of the ways in which gene mutations can have an impact on male fertility
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