48 research outputs found

    The landscape of DNA repeat elements in human heart failure.

    Get PDF
    BACKGROUND: The epigenomes of healthy and diseased human hearts were recently examined by genome-wide DNA methylation profiling. Repetitive elements, heavily methylated in post-natal tissue, have variable methylation profiles in cancer but methylation of repetitive elements in the heart has never been examined. RESULTS: We analyzed repetitive elements from all repeat families in human myocardial samples, and found that satellite repeat elements were significantly hypomethylated in end-stage cardiomyopathic hearts relative to healthy normal controls. Satellite repeat elements are almost always centromeric or juxtacentromeric, and their overexpression correlates with disease aggressiveness in cancer. Similarly, we found that hypomethylation of satellite repeat elements correlated with up to 27-fold upregulation of the corresponding transcripts in end-stage cardiomyopathic hearts. No other repeat family exhibited differential methylation between healthy and cardiomyopathic hearts, with the exception of the Alu element SINE1/7SL, for which a modestly consistent trend of increased methylation was observed. CONCLUSIONS: Satellite repeat element transcripts, a form of non-coding RNA, have putative functions in maintaining genomic stability and chromosomal integrity. Further studies will be needed to establish the functional significance of these non-coding RNAs in the context of heart failure

    High-throughput sequencing identifies STAT3 as the DNA-associated factor for p53-NF-kappaB-complex-dependent gene expression in human heart failure.

    Get PDF
    BACKGROUND: Genome-wide maps of DNA regulatory elements and their interaction with transcription factors may form a framework for understanding regulatory circuits and gene expression control in human disease, but how these networks, comprising transcription factors and DNA-binding proteins, form complexes, interact with DNA and modulate gene expression remains largely unknown. METHODS: Using microRNA-21 (mir-21), which is an example of genes that are regulated in heart failure, we performed chromatin immunoprecipitation (ChIP) assays to determine the occupancy of transcription factors at this genetic locus. Tissue ChIP was further performed using human hearts and genome-wide occupancies of these transcription factors were analyzed by high-throughput sequencing. RESULTS: We show that the transcription factor p53 piggy-backs onto NF-kappaB/RELA and utilizes the kappaB-motif at a cis-regulatory region to control mir-21 expression. p53 behaves as a co-factor in this complex because despite a mutation in its DNA binding domain, mutant p53 was still capable of binding RELA and the cis-element, and inducing mir-21 expression. In dilated human hearts where mir-21 upregulation was previously demonstrated, the p53-RELA complex was also associated with this cis-element. Using high-throughput sequencing, we analyzed genome-wide binding sites for the p53-RELA complex in diseased and control human hearts and found a significant overrepresentation of the STAT3 motif. We further determined that STAT3 was necessary for the p53-RELA complex to associate with this cis-element and for mir-21 expression. CONCLUSIONS: Our results uncover a mechanism by which transcription factors cooperate in a multi-molecular complex at a cis-regulatory element to control gene expression

    CTG repeat-targeting oligonucleotides for down-regulating Huntingtin expression

    Get PDF
    Sjuksköterskeyrket innebär ofta långvarig stress och bristfällig arbetsmiljö. Personalbrist, hög arbetsbelastning och bristande inflytande på arbetsplatsen är orsaker till att sjuksköterskor väljer att sluta inom yrket. För lite forskning gällande den upplevda stressen på arbetsplatsen inom sjuksköterskeyrket råder. Därför finns anledning till ökad kunskap kring ämnet. Syftet med studien är att undersöka i hur hög utsträckning sjuksköterskor upplever stress i sin arbetsmiljö, och studien är baserad på 1044 yrkesverksamma sjuksköterskor över hela landet som är medlemmar i Facebookgruppen ”Sjuksköterskan”. Dessa personer har fått svara på enkäten Work Stress Questionnaire med 21 frågor. Resultatet från denna studie visar att arbetsbelastningen ökat och personalen har inte möjlighet att påverka beslut som tas på arbetsplatsen. Konflikter är också förekommande där chefen, i de flesta fall, inte gör något för att lösa dessa konflikter. Sjuksköterskorna sätter höga krav på sig själva och är mycket engagerade i arbetet, men har ofta svårt att sätta gränser. Resultatet visar också att en hög andel har svårt att hinna med familj, vänner och fritidsintressen. Det finns tidigare studier med samma mätinstrument som visar att arbetsbelastningen och ansvarstagandet har ökat under de senaste åren. Eventuellt kan detta i slutändan innebära en risk för ökad utbrändhet och fler sjukskrivningar

    Distinct epigenomic features in end-stage failing human hearts

    Get PDF
    Background— The epigenome refers to marks on the genome, including DNA methylation and histone modifications, that regulate the expression of underlying genes. A consistent profile of gene expression changes in end-stage cardiomyopathy led us to hypothesize that distinct global patterns of the epigenome may also exist. Methods and Results— We constructed genome-wide maps of DNA methylation and histone-3 lysine-36 trimethylation (H3K36me3) enrichment for cardiomyopathic and normal human hearts. More than 506 Mb sequences per library were generated by high-throughput sequencing, allowing us to assign methylation scores to ≈28 million CG dinucleotides in the human genome. DNA methylation was significantly different in promoter CpG islands, intragenic CpG islands, gene bodies, and H3K36me3-enriched regions of the genome. DNA methylation differences were present in promoters of upregulated genes but not downregulated genes. H3K36me3 enrichment itself was also significantly different in coding regions of the genome. Specifically, abundance of RNA transcripts encoded by the DUX4 locus correlated to differential DNA methylation and H3K36me3 enrichment. In vitro, Dux gene expression was responsive to a specific inhibitor of DNA methyltransferase, and Dux siRNA knockdown led to reduced cell viability. Conclusions— Distinct epigenomic patterns exist in important DNA elements of the cardiac genome in human end-stage cardiomyopathy. The epigenome may control the expression of local or distal genes with critical functions in myocardial stress response. If epigenomic patterns track with disease progression, assays for the epigenome may be useful for assessing prognosis in heart failure. Further studies are needed to determine whether and how the epigenome contributes to the development of cardiomyopathy

    Effects of Dietary Restriction on Cancer Development and Progression

    Get PDF
    The effects of caloric restriction on tumor growth and progression are known for over a century. Indeed, fasting has been practiced for millennia, but just recently has emerged the protective role that it may exert toward cells. Fasting cycles are able to reprogram the cellular metabolism, by inducing protection against oxidative stress and prolonging cellular longevity. The reduction of calorie intake as well as short- or long-term fasting has been shown to protect against chronic and degenerative diseases, such as diabetes, cardiovascular pathologies, and cancer. In vitro and in vivo preclinical models showed that different restriction dietary regimens may be effective against cancer onset and progression, by enhancing therapy response and reducing its toxic side effects. Fasting-mediated beneficial effects seem to be due to the reduction of inflammatory response and downregulation of nutrient-related signaling pathways able to modulate cell proliferation and apoptosis. In this chapter, we will discuss the most significant studies present in literature regarding the molecular mechanisms by which dietary restriction may contribute to prevent cancer onset, reduce its progression, and positively affect the response to the treatments

    The first myriapod genome sequence reveals conservative arthropod gene content and genome organisation in the centipede Strigamia maritima.

    Get PDF
    Myriapods (e.g., centipedes and millipedes) display a simple homonomous body plan relative to other arthropods. All members of the class are terrestrial, but they attained terrestriality independently of insects. Myriapoda is the only arthropod class not represented by a sequenced genome. We present an analysis of the genome of the centipede Strigamia maritima. It retains a compact genome that has undergone less gene loss and shuffling than previously sequenced arthropods, and many orthologues of genes conserved from the bilaterian ancestor that have been lost in insects. Our analysis locates many genes in conserved macro-synteny contexts, and many small-scale examples of gene clustering. We describe several examples where S. maritima shows different solutions from insects to similar problems. The insect olfactory receptor gene family is absent from S. maritima, and olfaction in air is likely effected by expansion of other receptor gene families. For some genes S. maritima has evolved paralogues to generate coding sequence diversity, where insects use alternate splicing. This is most striking for the Dscam gene, which in Drosophila generates more than 100,000 alternate splice forms, but in S. maritima is encoded by over 100 paralogues. We see an intriguing linkage between the absence of any known photosensory proteins in a blind organism and the additional absence of canonical circadian clock genes. The phylogenetic position of myriapods allows us to identify where in arthropod phylogeny several particular molecular mechanisms and traits emerged. For example, we conclude that juvenile hormone signalling evolved with the emergence of the exoskeleton in the arthropods and that RR-1 containing cuticle proteins evolved in the lineage leading to Mandibulata. We also identify when various gene expansions and losses occurred. The genome of S. maritima offers us a unique glimpse into the ancestral arthropod genome, while also displaying many adaptations to its specific life history.This work was supported by the following grants: NHGRIU54HG003273 to R.A.G; EU Marie Curie ITN #215781 “Evonet” to M.A.; a Wellcome Trust Value in People (VIP) award to C.B. and Wellcome Trust graduate studentship WT089615MA to J.E.G; Marine rhythms of Life” of the University of Vienna, an FWF (http://www.fwf.ac.at/) START award (#AY0041321) and HFSP (http://www.hfsp.org/) research grant (#RGY0082/2010) to KT-­‐R; MFPL Vienna International PostDoctoral Program for Molecular Life Sciences (funded by Austrian Ministry of Science and Research and City of Vienna, Cultural Department -­‐Science and Research to T.K; Direct Grant (4053034) of the Chinese University of Hong Kong to J.H.L.H.; NHGRI HG004164 to G.M.; Danish Research Agency (FNU), Carlsberg Foundation, and Lundbeck Foundation to C.J.P.G.; U.S. National Institutes of Health R01AI55624 to J.H.W.; Royal Society University Research fellowship to F.M.J.; P.D.E. was supported by the BBSRC via the Babraham Institute;This is the final version of the article. It first appeared from PLOS via http://dx.doi.org/10.1371/journal.pbio.100200

    Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

    Get PDF
    Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

    Restoration of KMT2C/MLL3 in human colorectal cancer cells reinforces genome-wide H3K4me1 profiles and influences cell growth and gene expression

    No full text
    Background The histone 3 lysine 4 (H3K4) monomethylase KMT2C is mutated across several cancer types; however, the effects of mutations on epigenome organization, gene expression, and cell growth are not clear. A frequently recurring mutation in colorectal cancer (CRC) with microsatellite instability is a single nucleotide deletion within the exon 38 poly-A(9) repeat (c.8390delA) which results in frameshift preceding the functional carboxy-terminal SET domain. To study effects ofKMT2Cexpression in CRC cells, we restored one allele to wild typeKMT2Cin the two CRC cell lines RKO and HCT116, which both are homozygous c.8390delA mutant. Results Gene editing resulted in increasedKMT2Cexpression, increased H3K4me1 levels, altered gene expression profiles, and subtle negative effects on cell growth, where higher dependence and stronger effects ofKMT2Cexpression were observed in RKO compared to HCT116 cells. Surprisingly, we found that the two RKO and HCT116 CRC cell lines have distinct baseline H3K4me1 epigenomic profiles. In RKO cells, a flatter genome-wide H3K4me1 profile was associated with more increased H3K4me1 deposition at enhancers, reduced cell growth, and more differential gene expression relative to HCT116 cells when KMT2C was restored. Profiling of H3K4me1 did not indicate a highly specific regulation of gene expression as KMT2C-induced H3K4me1 deposition was found globally and not at a specific enhancer sub-set in the engineered cells. Although we observed variation in differentially regulated gene sets between cell lines and individual clones, differentially expressed genes in both cell lines included genes linked to known cancer signaling pathways, estrogen response, hypoxia response, and aspects of immune system regulation. Conclusions Here, KMT2C restoration reduced CRC cell growth and reinforced genome-wide H3K4me1 deposition at enhancers; however, the effects varied depending upon the H3K4me1 status of KMT2C deficient cells. Results indicate that KMT2C inactivation may promote colorectal cancer development through transcriptional dysregulation in several pathways with known cancer relevance
    corecore