Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 110
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Cell ; 133(7): 1145-8, 2008 Jun 27.
Article in English | MEDLINE | ID: mdl-18585349

ABSTRACT

Patterns of DNA cytosine methylation are subject to mitotic inheritance in both plants and vertebrates. Plants use 5-methylcytosine glycosylases and the base excision repair pathway to remove excess cytosine methylation. In mammals, active demethylation has been proposed to operate via several very different mechanisms. Two recent reports in Nature now claim that the demethylation process is initiated by the same enzymes that establish the methylation mark, the DNA methyltransferases DNMT3A and DNMT3B (Kangaspeska et al., 2008; Métivier et al., 2008).


Subject(s)
DNA Methylation , Animals , DNA/metabolism , DNA Modification Methylases/metabolism , Mammals/genetics , Mammals/metabolism , Plants/genetics , Plants/metabolism
2.
Scand J Prim Health Care ; 40(2): 281-288, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35815833

ABSTRACT

OBJECTIVE: To assess the extent of violence that is revealed by screening at first contact with a local out-of-hours emergency medical communication centre (LEMC; Norwegian 'Legevaktsentral'). DESIGN: Cross-sectional study. SETTING: Arendal LEMC, covering 10 municipalities in south-eastern Norway. All contacting patients (telephone or personal attendance) were asked by nurse whether the encounter was related to violence. SUBJECTS: All first patient encounters at Arendal LEMC. MAIN OUTCOME MEASURES: Number and proportion of cases where the nurses suspected violence, both domestic violence and other violence. Incidence rate of violence, age and gender distribution of patients, time of day and reason for encounter. RESULTS: Violence was suspected in 336 of 103,467 first patient encounters (0.3%), of which 132 (0.1%) was domestic violence. Patients were female in 50.6% of all violence cases, and in 79% of domestic violence cases. Incidence rates were 137 per 100,000 person-years for all violence, and 53 for domestic violence. CONCLUSIONS: This study indicates violence may be revealed in three of 1000 first encounters to an LEMC when nurses screen systematically for domestic or other violence.Key points    Violence as underlying reason for encounter with primary care emergency health services is probably often not discovered by health personnel. • We examined how often nurses reveal violence upon first contact when systematically asking all patients. • Violence was suspected in 0.3% of cases, and domestic violence in 0.1%. • Among patients with disclosed domestic violence, 79% were female.


Subject(s)
Domestic Violence , Emergency Medical Services , Communication , Cross-Sectional Studies , Female , Humans , Male , Mass Screening
3.
Hum Genet ; 138(4): 293-305, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30840129

ABSTRACT

The understanding that differences in biological epistasis may impact disease risk, diagnosis, or disease management stands in wide contrast to the unavailability of widely accepted large-scale epistasis analysis protocols. Several choices in the analysis workflow will impact false-positive and false-negative rates. One of these choices relates to the exploitation of particular modelling or testing strategies. The strengths and limitations of these need to be well understood, as well as the contexts in which these hold. This will contribute to determining the potentially complementary value of epistasis detection workflows and is expected to increase replication success with biological relevance. In this contribution, we take a recently introduced regression-based epistasis detection tool as a leading example to review the key elements that need to be considered to fully appreciate the value of analytical epistasis detection performance assessments. We point out unresolved hurdles and give our perspectives towards overcoming these.


Subject(s)
Data Interpretation, Statistical , Epistasis, Genetic/physiology , Genome-Wide Association Study/statistics & numerical data , Culture , False Positive Reactions , Genetic Testing/methods , Genetic Testing/statistics & numerical data , Genome-Wide Association Study/methods , Humans , Polymorphism, Single Nucleotide
4.
Int J Obes (Lond) ; 43(9): 1880-1881, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31388095

ABSTRACT

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

5.
Appl Environ Microbiol ; 85(21)2019 11 01.
Article in English | MEDLINE | ID: mdl-31420347

ABSTRACT

Exposure to fungal spores has been associated with respiratory symptoms and allergic alveolitis among sawmill workers, but the complexity of sawmill workers' fungal exposure has been poorly studied. We characterized the fungal diversity in air samples from sawmill workers' breathing zones and identified differences in the richness, diversity, and taxonomic composition between companies, departments, wood types, and seasons. Full-shift personal inhalable dust samples (n = 86) collected from 11 industrial sawmill, sorting mill, and planer mill companies processing spruce and/or pine were subjected to DNA metabarcoding using the fungal internal transcribed spacer (ITS) region 2. The workers were exposed to a higher total number of operational taxonomic units (OTUs) in summer than in winter and when processing spruce than when processing pine. Workers in the saw department had the richest fungal exposure, followed by workers in the planing department and sorting of dry timber department. Sawmills explained 11% of the variation in the fungal community composition of the exposure, followed by season (5%) and department (3%). The fungal compositions of the exposures also differed between seasons, sawmills, wood types, and departments at the taxonomic level, ranging from the phylum to the species level. The differences in exposure diversity suggest that the potential health effects of fungal inhalation may also be different; hence, a risk assessment based on the fungal diversity differences should be performed. This study may serve as a basis for establishing a fungal profile of signature species that are specific for sawmills and that can be measured quantitatively in future risk assessments of sawmill workers.IMPORTANCE To gain more knowledge about exposure-response relationships, it is important to improve exposure characterization by comprehensively identifying the temporal and spatial fungal composition and diversity of inhalable dust at workplaces. The variation in the diverse fungal communities to which individuals are exposed in different seasons and sawmills suggests that variations in exposure-related health effects between seasons and companies can be expected. More importantly, the distinct fungal profiles between departments across companies indicate that workers in different job groups are differently exposed and that health risks can be department specific. DNA metabarcoding provides insight into a broad spectrum of airborne fungi that may serve as a basis for obtaining important knowledge about the fungi to which workers are exposed.


Subject(s)
Biodiversity , Inhalation Exposure , Mycobiome , Occupational Exposure , Wood , Air , Air Microbiology , Dust , Environmental Monitoring , Fungi/classification , Humans , Multivariate Analysis , Phylogeny , Spores, Fungal
6.
Purinergic Signal ; 15(2): 265-276, 2019 06.
Article in English | MEDLINE | ID: mdl-31129780

ABSTRACT

Urosepsis is a severe condition often caused by Escherichia coli that spontaneously have ascended the urinary tract to the kidneys causing pyelonephritis and potentially bacteraemia. The number of sepsis cases has been steadily increasing over the last decades, and there are still no specific, molecular supportive therapies for sepsis to supplement antibiotic treatment. P2X1 receptors are expressed by a number of immune cells including thrombocytes, which presently have been established as an important player in the acute immune response to bacterial infections. P2X1 receptor-deficient mice have been shown to be relatively protected against urosepsis, with markedly reduced levels of circulating proinflammatory cytokines and intravascular coagulation. However, here we show that continuous intravenous infusion with P2X1 receptor antagonist markedly accelerates development of a septic response to induced bacteraemia with uropathogenic E. coli. Mice exposed to the P2X1 receptor antagonists die very early with haematuria, substantially elevated plasma levels of proinflammatory cytokines, massive intravascular coagulation and a concomitant reduction in circulating thrombocytes. Interestingly, infusion of P2X1 receptor antagonists causes a marked acute reduction in circulating thrombocytes and a higher number of bacteria in the blood. These data support the notion that the number of functional thrombocytes is important for the acute defence against bacteria in the circulation and that the P2X1 receptor potentially could be essential for this response.


Subject(s)
Blood Platelets/drug effects , Escherichia coli Infections , Purinergic P2X Receptor Antagonists/pharmacology , Receptors, Purinergic P2X1 , Sepsis , Urinary Tract Infections , Animals , Benzenesulfonates , Hemolysin Proteins , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , Pyelonephritis , Suramin/analogs & derivatives , Uropathogenic Escherichia coli
7.
Nucleic Acids Res ; 45(16): 9398-9412, 2017 09 19.
Article in English | MEDLINE | ID: mdl-28934503

ABSTRACT

In mammals, faithful inheritance of genomic methylation patterns ensures proper gene regulation and cell behaviour, impacting normal development and fertility. Following establishment, genomic methylation patterns are transmitted through S-phase by the maintenance methyltransferase Dnmt1. Using a protein interaction screen, we identify Microprocessor component DROSHA as a novel DNMT1-interactor. Drosha-deficient embryonic stem (ES) cells display genomic hypomethylation that is not accounted for by changes in the levels of DNMT proteins. DNMT1-mediated methyltransferase activity is also reduced in these cells. We identify two transcripts that are specifically upregulated in Drosha- but not Dicer-deficient ES cells. Regions within these transcripts predicted to form stem-loop structures are processed by Microprocessor and can inhibit DNMT1-mediated methylation in vitro. Our results highlight DROSHA as a novel regulator of mammalian DNA methylation and we propose that DROSHA-mediated processing of RNA is necessary to ensure full DNMT1 activity. This adds to the DROSHA repertoire of non-miRNA dependent functions as well as implicating RNA in regulating DNMT1 activity and correct levels of genomic methylation.


Subject(s)
DNA (Cytosine-5-)-Methyltransferases/metabolism , DNA Methylation , Ribonuclease III/physiology , Animals , CRISPR-Cas Systems , Cells, Cultured , Cytosine/metabolism , DNA (Cytosine-5-)-Methyltransferase 1 , Embryonic Stem Cells/enzymology , HEK293 Cells , Humans , Mice , RNA, Messenger/chemistry , RNA, Messenger/metabolism , Ribonuclease III/genetics , Ribonuclease III/metabolism , Up-Regulation
8.
Int J Obes (Lond) ; 42(2): 139-146, 2018 02.
Article in English | MEDLINE | ID: mdl-28894292

ABSTRACT

BACKGROUND: Bariatric surgery remains the most effective treatment for reducing adiposity and eliminating type 2 diabetes; however, the mechanism(s) responsible have remained elusive. Peroxisome proliferator-activated receptors (PPAR) encompass a family of nuclear hormone receptors that upon activation exert control of lipid metabolism, glucose regulation and inflammation. Their role in adipose tissue following bariatric surgery remains undefined. MATERIALS AND METHODS: Subcutaneous adipose tissue biopsies and serum were obtained and evaluated from time of surgery and on postoperative day 7 in patients randomized to Roux-en-Y gastric bypass (n=13) or matched caloric restriction (n=14), as well as patients undergoing vertical sleeve gastrectomy (n=33). Fat samples were evaluated for changes in gene expression, protein levels, ß-oxidation, lipolysis and cysteine oxidation. RESULTS: Within 7 days, bariatric surgery acutely drives a change in the activity and expression of PPARγ and PPARδ in subcutaneous adipose tissue thereby attenuating lipid storage, increasing lipolysis and potentiating lipid oxidation. This unique metabolic alteration leads to changes in downstream PPARγ/δ targets including decreased expression of fatty acid binding protein (FABP) 4 and stearoyl-CoA desaturase-1 (SCD1) with increased expression of carnitine palmitoyl transferase 1 (CPT1) and uncoupling protein 2 (UCP2). Increased expression of UCP2 not only facilitated fatty acid oxidation (increased 15-fold following surgery) but also regulated the subcutaneous adipose tissue redoxome by attenuating protein cysteine oxidation and reducing oxidative stress. The expression of UCP1, a mitochondrial protein responsible for the regulation of fatty acid oxidation and thermogenesis in beige and brown fat, was unaltered following surgery. CONCLUSIONS: These results suggest that bariatric surgery initiates a novel metabolic shift in subcutaneous adipose tissue to oxidize fatty acids independently from the beiging process through regulation of PPAR isoforms. Further studies are required to understand the contribution of this shift in expression of PPAR isoforms to weight loss following bariatric surgery.


Subject(s)
Bariatric Surgery , Diabetes Mellitus, Type 2/prevention & control , Lipid Metabolism/physiology , Obesity, Morbid/surgery , PPAR delta/physiology , Subcutaneous Fat/metabolism , Adult , Fatty Acid-Binding Proteins/metabolism , Female , Gene Expression Regulation , Humans , Immunoblotting , Lipolysis/physiology , Male , Obesity, Morbid/metabolism , Treatment Outcome , Uncoupling Protein 2/metabolism
9.
Crit Care ; 22(1): 181, 2018 08 02.
Article in English | MEDLINE | ID: mdl-30071869

ABSTRACT

BACKGROUND: Pore-forming proteins released from bacteria or formed as result of complement activation are known to produce severe cell damage. Inhibition of purinergic P2X receptors markedly reduces damage inflicted by cytolytic bacterial toxin and after complement activation in both erythrocytes and monocytes. P2X expression generally shows variation throughout the population. Here, we investigate correlation between P2X receptor abundance in blood cell plasma membranes and haematocrit during sepsis, in patients admitted to the emergency department (ED) or intensive care unit (ICU). METHOD: Patients admitted to the ED and successively transferred to ICU with the diagnosis sepsis (< 2 systemic inflammatory response syndrome (SIRS) criteria and suspected infection), were grouped as either blood pathogen-positive (14 patients) or blood pathogen-negative (20 patients). Blood samples drawn at ICU admission were analysed for P2X1 and P2X7 receptor abundance using indirect flow cytometry. RESULTS: Here, we find inverse correlation between P2X1 receptor expression and change in haematocrit (rs - 0.80) and haemoglobin (rs - 0.78) levels from admission to ED to arrival at ICU in patients with pathogen-positive sepsis. This correlation was not found in patients without confirmed bacteraemia. Patients with high P2X1 expression had a significantly greater change in both haematocrit (- 0.59 ± 0.36) and haemoglobin levels (- 0.182 ± 0.038 mg/dl) per hour, during the first hours after hospital admission compared to patients with low P2X1 expression (0.007 ± 0.182 and - 0.020 ± 0.058 mg/dl, respectively). CONCLUSION: High levels of P2X1 are correlated with more pronounced reduction in haematocrit and haemoglobin in patients with confirmed bacteraemia. This supports previous in vitro findings of P2X activation as a significant component in cell damage caused by pore-forming bacterial toxins and complement-dependent major attack complex. These data suggest a new potential target for future therapeutics in initial stages of sepsis.


Subject(s)
Hematocrit/methods , Receptors, Purinergic P2X1/analysis , Sepsis/blood , Aged , Bacterial Toxins/blood , Emergency Service, Hospital/organization & administration , Emergency Service, Hospital/statistics & numerical data , Enzyme-Linked Immunosorbent Assay/methods , Female , Gram-Negative Bacteria/enzymology , Gram-Negative Bacteria/pathogenicity , Gram-Positive Bacteria/enzymology , Gram-Positive Bacteria/pathogenicity , Hematocrit/statistics & numerical data , Humans , Intensive Care Units/organization & administration , Intensive Care Units/statistics & numerical data , Male , Middle Aged , Prospective Studies , Receptors, Purinergic P2X1/blood , Systemic Inflammatory Response Syndrome , Vitamin D/analysis , Vitamin D/blood
10.
J Membr Biol ; 250(3): 301-313, 2017 06.
Article in English | MEDLINE | ID: mdl-28488084

ABSTRACT

Uropathogenic Escherichia coli often produce the virulence factor α-hemolysin (HlyA), and the more severe the infection, the likelier it is to isolate HlyA-producing E. coli from patients. HlyA forms pores upon receptor-independent insertion of the toxin into biological membranes and it has been substantiated that HlyA-induced hemolysis is amplified by toxin-induced ATP release and activation of P2X receptors. Thus, hemolysis inflicted by HlyA is a protracted process involving signal transduction. It consists of early, marked cell shrinkage followed by swelling and eventually lysis. The initially shrinkage is a consequence of a substantial Ca2+-influx and activation of Ca2+-sensitive K+ and Cl- channels (KCa3.1/TMEM16A). The shrinkage is followed by gradual cell swelling, which ultimately lyses the cells. These findings clearly show that the HlyA pore provides a substantial volume challenge for the cells, and the fate of the given cell is co-determined by intrinsic erythrocytal volume regulation. We therefore speculated that other mechanisms involved in erythrocyte volume regulation may influence the hemolytic process inflicted by HlyA. Strikingly, HlyA-induced hemolysis is markedly reduced in erythrocytes isolated from NKCC1-deficient (NKCC1-/-) mice compared to controls. The NKCC1 inhibitors furosemide and bumetanide concentration-dependently inhibit HlyA-induced lysis of human and murine erythrocytes. However, in high concentrations bumetanide further reduced hemolysis in erythrocytes from NKCC1-/- mice and, thus, also exhibit indirect effects on hemolysis. The effect of loop diuretics on the hemolysis is not unique to HlyA but is similarly seen in LtxA- and α-toxin-induced hemolysis. Bumetanide clearly potentiates HlyA-induced volume reduction and delays the following erythrocyte swelling. This allows increased phagocytosis of damaged erythrocytes by THP-1 cell as a result of prolonged cell shrinkage. These data suggest that erythrocyte susceptibility to cytolysins is modified by NKCC1 and signifies intrinsic volume regulators as important determinants of cellular outcome of pore-forming toxins.


Subject(s)
Escherichia coli/chemistry , Hemolysin Proteins/pharmacology , Animals , Bacterial Proteins/pharmacology , Erythrocytes/drug effects , Erythrocytes/metabolism , Furosemide/pharmacology , Hemolysis/drug effects , Humans , Mice , Mice, Knockout , Phagocytosis/drug effects , Solute Carrier Family 12, Member 2/deficiency , Solute Carrier Family 12, Member 2/genetics , Solute Carrier Family 12, Member 2/metabolism , THP-1 Cells
11.
J Biol Chem ; 290(23): 14776-84, 2015 Jun 05.
Article in English | MEDLINE | ID: mdl-25911098

ABSTRACT

Urinary tract infections are commonly caused by α-hemolysin (HlyA)-producing Escherichia coli. In erythrocytes, the cytotoxic effect of HlyA is strongly amplified by P2X receptors, which are activated by extracellular ATP released from the cytosol of the erythrocytes. In renal epithelia, HlyA causes reversible [Ca(2+)]i oscillations, which trigger interleukin-6 (IL-6) and IL-8 release. We speculate that this effect is caused by HlyA-induced ATP release from the epithelial cells and successive P2 receptor activation. Here, we demonstrate that HlyA-induced [Ca(2+)]i oscillations in renal epithelia were completely prevented by scavenging extracellular ATP. In accordance, HlyA was unable to inflict any [Ca(2+)]i oscillations in 132-1N1 cells, which lack P2R completely. After transfecting these cells with the hP2Y2 receptor, HlyA readily triggered [Ca(2+)]i oscillations, which were abolished by P2 receptor antagonists. Moreover, HlyA-induced [Ca(2+)]i oscillations were markedly reduced in medullary thick ascending limbs isolated from P2Y2 receptor-deficient mice compared with wild type. Interestingly, the following HlyA-induced IL-6 release was absent in P2Y2 receptor-deficient mice. This suggests that HlyA induces ATP release from renal epithelia, which via P2Y2 receptors is the main mediator of HlyA-induced [Ca(2+)]i oscillations and IL-6 release. This supports the notion that ATP signaling occurs early during bacterial infection and is a key player in the further inflammatory response.


Subject(s)
Escherichia coli Infections/immunology , Escherichia coli Proteins/immunology , Escherichia coli/physiology , Hemolysin Proteins/immunology , Interleukin-6/immunology , Kidney/microbiology , Receptors, Purinergic P2Y2/immunology , Urothelium/microbiology , Adenosine Triphosphate/immunology , Animals , Calcium Signaling , Cell Line , Dogs , Escherichia coli/immunology , Humans , Kidney/immunology , Mice , Urothelium/immunology
12.
Infect Immun ; 84(11): 3114-3130, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27528275

ABSTRACT

α-Hemolysin (HlyA) from Escherichia coli and leukotoxin A (LtxA) from Aggregatibacter actinomycetemcomitans are important virulence factors in ascending urinary tract infections and aggressive periodontitis, respectively. The extracellular signaling molecule ATP is released immediately after insertion of the toxins into plasma membranes and, via P2X receptors, is essential for the erythrocyte damage inflicted by these toxins. Moreover, ATP signaling is required for the ensuing recognition and phagocytosis of damaged erythrocytes by the monocytic cell line THP-1. Here, we investigate how these toxins affect THP-1 monocyte function. We demonstrate that both toxins trigger early ATP release and a following increase in the intracellular Ca2+ concentration ([Ca2+]i) in THP-1 monocytes. The HlyA- and LtxA-induced [Ca2+]i response is diminished by the P2 receptor antagonist in a pattern that fits the functional P2 receptor expression in these cells. Both toxins are capable of lysing THP-1 cells, with LtxA being more aggressive. Either desensitization or blockage of P2X1, P2X4, or P2X7 receptors markedly reduces toxin-induced cytolysis. This pattern is paralleled in freshly isolated human monocytes from healthy volunteers. Interestingly, only a minor fraction of the toxin-damaged THP-1 monocytes eventually lyse. P2X7 receptor inhibition generally prevents cell damage, except from a distinct cell shrinkage that prevails in response to the toxins. Moreover, we find that preexposure to HlyA preserves the capacity of THP-1 monocytes to phagocytose damaged erythrocytes and may induce readiness to discriminate between damaged and healthy erythrocytes. These findings suggest a new pharmacological target for protecting monocytes during exposure to pore-forming cytolysins during infection or injury.


Subject(s)
Aggregatibacter actinomycetemcomitans/metabolism , Bacterial Toxins/toxicity , Escherichia coli/metabolism , Hemolysin Proteins/toxicity , Monocytes/drug effects , Receptors, Purinergic P2X/physiology , Bacterial Toxins/metabolism , Cell Death/drug effects , Cytoplasm/metabolism , Cytotoxins/metabolism , Erythrocytes/metabolism , Escherichia coli Proteins/metabolism , Escherichia coli Proteins/toxicity , Exotoxins/metabolism , Exotoxins/toxicity , Hemolysin Proteins/metabolism , Hemolysis/physiology , Humans , Monocytes/metabolism
13.
Mol Genet Genomics ; 290(1): 201-15, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25213601

ABSTRACT

Insecticide resistance is a major impediment to the control of vectors and pests of public health importance and is a strongly selected trait capable of rapid spread, sometimes even between closely related species. Elucidating the mechanisms generating insecticide resistance in mosquito vectors of disease, and understanding the spread of resistance within and between populations and species are vital for the development of robust resistance management strategies. Here, we studied the mechanisms of resistance in two sympatric members of the Anopheles gambiae species complex-the major vector of malaria in sub-Saharan Africa-to understand how resistance has developed and spread in eastern Uganda, a region with some of the highest levels of malaria. In eastern Uganda, where the mosquitoes Anopheles arabiensis and An. gambiae can be found sympatrically, low levels of hybrids (0.4 %) occur, offering a route for introgression of adaptively important variants between species. In independent microarray studies of insecticide resistance, Gste4, an insect-specific glutathione S-transferase, was among the most significantly up-regulated genes in both species. To test the hypothesis of interspecific introgression, we sequenced 2.3 kbp encompassing Gste4. Whilst this detailed sequencing ruled out introgression, we detected strong positive selection acting on Gste4. However, these sequences, followed by haplotype-specific qPCR, showed that the apparent up-regulation in An. arabiensis is a result of allelic variation across the microarray probe binding sites which artefactually elevates the gene expression signal. Thus, face-value acceptance of microarray data can be misleading and it is advisable to conduct a more detailed investigation of the causes and nature of such signal. The identification of positive selection acting on this locus led us to functionally express and characterise allelic variants of GSTE4. Although the in vitro data do not support a direct role for GSTE4 in metabolism, they do support a role for this enzyme in insecticide sequestration. Thus, the demonstration of a role for an up-regulated gene in metabolic resistance to insecticides should not be limited to simply whether it can metabolise insecticide; such a strict criterion would argue against the involvement of GSTE4 despite the weight of evidence to the contrary.


Subject(s)
Anopheles/genetics , Biological Evolution , Inactivation, Metabolic , Insect Proteins/metabolism , Pyrethrins/metabolism , Selection, Genetic , Animals , Anopheles/metabolism , Base Sequence , Gene Expression Regulation , Genome, Insect , Genotyping Techniques , Haplotypes/genetics , Hydrogen-Ion Concentration , Insect Proteins/chemistry , Insect Proteins/genetics , Insecticide Resistance/drug effects , Kinetics , Molecular Sequence Data , Nitriles/toxicity , Oligonucleotide Array Sequence Analysis , Phylogeny , Polymorphism, Single Nucleotide/genetics , Pyrethrins/toxicity , Recombinant Proteins/metabolism , Reproducibility of Results , Temperature
14.
J Virol ; 88(18): 10680-95, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24991018

ABSTRACT

UNLABELLED: Mammalian genomes are replete with retrotransposable elements, including endogenous retroviruses. DNA methyltransferase 3-like (DNMT3L) is an epigenetic regulator expressed in prospermatogonia, growing oocytes, and embryonic stem (ES) cells. Here, we demonstrate that DNMT3L enhances the interaction of repressive epigenetic modifiers, including histone deacetylase 1 (HDAC1), SET domain, bifurcated 1 (SETDB1), DNA methyltransferase 3A (DNMT3A), and tripartite motif-containing protein 28 (TRIM28; also known as TIF1ß and KAP1) in ES cells and orchestrates retroviral silencing activity with TRIM28 through mechanisms including, but not limited to, de novo DNA methylation. Ectopic expression of DNMT3L in somatic cells causes methylation-independent retroviral silencing activity by recruitment of the TRIM28/HDAC1/SETDB1/DNMT3A/DNMT3L complex to newly integrated Moloney murine leukemia virus (Mo-MuLV) proviral DNA. Concurrent with this recruitment, we also observed the accumulation of histone H3 lysine 9 trimethylation (H3K9me3) and heterochromatin protein 1 gamma (HP1γ), as well as reduced H3K9 and H3K27 acetylation at Mo-MuLV proviral sequences. Ectopic expression of DNMT3L in late-passage mouse embryonic fibroblasts (MEFs) recruited cytoplasmically localized HDAC1 to the nucleus. The formation of this epigenetic modifying complex requires interaction of DNMT3L with DNMT3A as well as with histone H3. In fetal testes at embryonic day 17.5, endogenous DNMT3L also enhanced the binding among TRIM28, DNMT3A, SETDB1, and HDAC1. We propose that DNMT3L may be involved in initiating a cascade of repressive epigenetic modifications by assisting in the preparation of a chromatin context that further attracts DNMT3A-DNMT3L binding and installs longer-term DNA methylation marks at newly integrated retroviruses. IMPORTANCE: Almost half of the mammalian genome is composed of endogenous retroviruses and other retrotransposable elements that threaten genomic integrity. These elements are usually subject to epigenetic silencing. We discovered that two epigenetic regulators that lack enzymatic activity, DNA methyltransferase 3-like (DNMT3L) and tripartite motif-containing protein 28 (TRIM28), collaborate with each other to impose retroviral silencing. In addition to modulating de novo DNA methylation, we found that by interacting with TRIM28, DNMT3L can attract various enzymes to form a DNMT3L-induced repressive complex to remove active marks and add repressive marks to histone proteins. Collectively, these results reveal a novel and pivotal function of DNMT3L in shaping the chromatin modifications necessary for retroviral and retrotransposon silencing.


Subject(s)
DNA (Cytosine-5-)-Methyltransferases/metabolism , Gene Silencing , Leukemia, Experimental/enzymology , Leukemia, Experimental/genetics , Moloney murine leukemia virus/physiology , Repressor Proteins/metabolism , Animals , DNA (Cytosine-5-)-Methyltransferases/genetics , DNA Methyltransferase 3A , Embryonic Stem Cells/enzymology , Embryonic Stem Cells/metabolism , Gene Expression , Histone Deacetylase 1/genetics , Histone Deacetylase 1/metabolism , Histones/metabolism , Humans , Leukemia, Experimental/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Moloney murine leukemia virus/genetics , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Protein Binding , Repressor Proteins/genetics , Tripartite Motif-Containing Protein 28
16.
Dis Esophagus ; 27(8): 726-31, 2014.
Article in English | MEDLINE | ID: mdl-24118437

ABSTRACT

Impedance baseline is a new parameter recently related to esophageal integrity. The aim of this study was to assess the effect of different factors on impedance baseline in pediatric patients. We analyzed the impedance baseline of 800 children with symptoms of gastroesophageal reflux. Mean impedance baseline was automatically calculated throughout 24-hour tracings. The presence of different age groups and of esophagitis was evaluated. Unpaired t-test, Spearman rank correlation, polynomial, and regression plot were used for statistical analysis. Age-related percentile curves were created. We considered a P-value<0.05 as statistically significant. Impedance baseline was significantly (P<0.001) lower in younger compared to older children up to 48 months. The mean increase of baseline per month was much higher in the first 36 months of life (47.5 vs. 2.9 Ohm in Channel 1 and 29.9 vs. 2.3 Ohm in Channel 6, respectively) than in older ages. Patients with esophagitis showed significantly decreased impedance baseline (P<0.05). Infants (especially in the first months of life) and young children present a significantly lower impedance baseline compared to older children both in proximal and distal esophagus. The presence of esophagitis may also determine a decreased impedance baseline regardless of the age of the patients.


Subject(s)
Esophagitis/physiopathology , Esophagus/physiopathology , Adolescent , Age Factors , Child , Child, Preschool , Electric Impedance , Esophageal pH Monitoring , Esophagitis/diagnosis , Esophagoscopy , Female , Gastroesophageal Reflux/diagnosis , Humans , Infant , Infant, Newborn , Male
17.
Nature ; 448(7154): 714-7, 2007 Aug 09.
Article in English | MEDLINE | ID: mdl-17687327

ABSTRACT

Mammals use DNA methylation for the heritable silencing of retrotransposons and imprinted genes and for the inactivation of the X chromosome in females. The establishment of patterns of DNA methylation during gametogenesis depends in part on DNMT3L, an enzymatically inactive regulatory factor that is related in sequence to the DNA methyltransferases DNMT3A and DNMT3B. The main proteins that interact in vivo with the product of an epitope-tagged allele of the endogenous Dnmt3L gene were identified by mass spectrometry as DNMT3A2, DNMT3B and the four core histones. Peptide interaction assays showed that DNMT3L specifically interacts with the extreme amino terminus of histone H3; this interaction was strongly inhibited by methylation at lysine 4 of histone H3 but was insensitive to modifications at other positions. Crystallographic studies of human DNMT3L showed that the protein has a carboxy-terminal methyltransferase-like domain and an N-terminal cysteine-rich domain. Cocrystallization of DNMT3L with the tail of histone H3 revealed that the tail bound to the cysteine-rich domain of DNMT3L, and substitution of key residues in the binding site eliminated the H3 tail-DNMT3L interaction. These data indicate that DNMT3L recognizes histone H3 tails that are unmethylated at lysine 4 and induces de novo DNA methylation by recruitment or activation of DNMT3A2.


Subject(s)
DNA (Cytosine-5-)-Methyltransferases/metabolism , DNA Methylation , Histones/metabolism , Lysine/metabolism , Animals , Cell Line , Crystallography, X-Ray , DNA/metabolism , DNA (Cytosine-5-)-Methyltransferases/chemistry , DNA (Cytosine-5-)-Methyltransferases/genetics , DNA Methyltransferase 3A , Embryonic Stem Cells/metabolism , Histones/chemistry , Humans , Mice , Protein Binding , Protein Structure, Tertiary , Structure-Activity Relationship , DNA Methyltransferase 3B
18.
Gut ; 61(4): 528-34, 2012 Apr.
Article in English | MEDLINE | ID: mdl-21708824

ABSTRACT

BACKGROUND: Haptoglobin (Hp) is a haemoglobin-binding protein with immunomodulatory properties. Its gene (16q22) harbours a common polymorphism with two different alleles: Hp1 and Hp2. Genotype Hp22 has been shown to be over-represented in different immune diseases. Results in Crohn's disease (CD) are contradictory. AIMS: To determine whether Hp plays a role in inflammatory bowel disease, both genetically and functionally. METHODS: 1061 patients with CD, 755 with ulcerative colitis (UC) and 152 with primary sclerosing cholangitis, as well as 452 healthy controls, were genotyped using touch-down PCR. To confirm association results, 464 CD trios and 151 UC trios were genotyped. Serum Hp concentrations were determined in 62 individuals of different genotype. Colitis was induced in mice with dextran sulphate sodium (DSS) and oxazolone (Oxa). Cytokine production was evaluated by mRNA quantification in colonic tissue and ELISA on supernatants of mesenteric lymph node cells. RESULTS: Prevalence of Hp2 was higher in CD and UC than in controls. In the confirmatory cohorts, Hp2 was over-transmitted to the affected offspring. Serum Hp concentrations were higher in individuals with genotypes Hp11 and Hp21 than in those with Hp22 (1.38 vs 0.89 g/l). DSS- and Oxa-induced colitis were more severe in Hp-deficient mice than in control mice and accompanied by higher concentrations (although not statistically significantly different) of tissue mRNA for cytokines. Interleukin-17 production was significantly higher in the presence of Hp-deficient serum compared with wild-type serum. CONCLUSIONS: The Hp gene may play a role in susceptibility to inflammatory bowel disease. Its implication in other immune diseases underscores the common pathways between these diseases. Experimental models of colitis showed that Hp has a protective role in inflammatory colitis, most likely by inhibiting the production of Th1 and Th17 cytokines.


Subject(s)
Haptoglobins/genetics , Inflammatory Bowel Diseases/genetics , Polymorphism, Genetic , Adult , Animals , Cholangitis, Sclerosing/genetics , Cholangitis, Sclerosing/metabolism , Colitis/chemically induced , Colitis/genetics , Colitis/metabolism , Colitis, Ulcerative/genetics , Colitis, Ulcerative/metabolism , Colon/metabolism , Crohn Disease/genetics , Crohn Disease/metabolism , Cytokines/biosynthesis , Disease Models, Animal , Female , Genetic Predisposition to Disease , Genotype , Haptoglobins/deficiency , Haptoglobins/metabolism , Humans , Inflammation Mediators/metabolism , Inflammatory Bowel Diseases/metabolism , Male , Mice , Mice, Knockout , Young Adult
19.
J Intensive Care Soc ; 24(4): 442-445, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37841303

ABSTRACT

The aim of this study was to assess the feasibility and outcome of a neuropsychiatric evaluation protocol intended for adult intensive care unit survivors in a Danish regional hospital, in which a follow-up consultation was conducted 2 months after hospital discharge. Twenty-three participants were able to finalize the neuropsychiatric evaluation, and 20 (87%) among those were detected with neuropsychiatric manifestations, including cognitive impairment (n = 17; 74%) and fatigue (n = 17, 74%). This study finds a high prevalence of neuropsychiatric manifestations and fatigue, and evaluates a follow-up protocol for the ICU patient population.

20.
Palliat Med Rep ; 4(1): 326-333, 2023.
Article in English | MEDLINE | ID: mdl-38098857

ABSTRACT

Background: Cannabis may offer therapeutic benefits to patients with advanced cancer not responding adequately to conventional palliative treatment. However, tolerability is a major concern. Cognitive function is a potential adverse reaction to tetrahydrocannabinol containing regimens. The aim of this study was to test cognitive function in patients being prescribed dronabinol as an adjuvant palliative therapy. Methods: Adult patients with advanced cancer and severe related pain refractory to conventional palliative treatment were included in this case-series study. Patients were examined at baseline in conjunction with initiation of dronabinol therapy and at a two-week follow-up using three selected Wechsler's adult intelligence scale III neurocognitive tests: Processing Speed Index (PSI), Perceptual Organization Index (POI), and Working Memory Index (WMI). Patients were also assessed using pain visual analog scale, Major Depression Inventory, and Brief Fatigue Inventory. Results: Eight patients consented to take part in the study. Two patients discontinued dronabinol therapy, one due to a complaint of dizziness and another critical progression of cancer disease, respectively. The remaining six patients were successfully treated with a daily dosage of 12.5 mg dronabinol (p = 0.039). PSI (p = 0.020), POI (p = 0.034.), and WMI (p = 0.039). Conclusions: Cognitive function improved in this group of patients with advanced cancer in conjunction with low-dose dronabinol therapy. The cause is likely multifactorial including reported relief of cancer-associated symptoms. Further clinical investigation is required.

SELECTION OF CITATIONS
SEARCH DETAIL