20 research outputs found

    The role of DNA methylation in transcriptional regulation of the human type 1 alpha 2 collagen (COL1A2) gene

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    Bibliography leaves 70-97.Type I collagen is the most abundant collagen molecule in vertebrate connective tissue and it consists of a heterotrimer of two alpha 1 (COL1A1) and one alpha 2 (COL1A2) chains. Reduced collagen gene expression is almost always correlated with pathological conditions and cellular transformation. Numerous studies have suggested that methylation of the cytosines in CpG dinucleotides is inversely correlated with transcriptional activity and plays a critical role in differential gene expression

    Phagocytosis of necrotic cells by macrophages is phosphatidylserine dependent and does not induce inflammatory cytokine production

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    Apoptotic cells are cleared by phagocytosis during development, homeostasis, and pathology. However, it is still unclear how necrotic cells are removed. We compared the phagocytic uptake by macrophages of variants of L929sA murine fibrosarcoma cells induced to die by tumor necrosis factor-induced necrosis or by Fas-mediated apoptosis. We show that apoptotic and necrotic cells are recognized and phagocytosed by macrophages, whereas living cells are not. In both cases, phagocytosis occurred through a phosphatidylserine-dependent mechanism, suggesting that externalization of phosphatidylserine is a general trigger for clearance by macrophages. However, uptake of apoptotic cells was more efficient both quantitatively and kinetically than phagocytosis of necrotic cells. Electron microscopy showed clear morphological differences in the mechanisms used by macrophages to engulf necrotic and apoptotic cells. Apoptotic cells were taken up as condensed membrane-bound particles of various sizes rather than as whole cells, whereas necrotic cells were internalized only as small cellular particles after loss of membrane integrity. Uptake of neither apoptotic nor necrotic L929 cells by macrophages modulated the expression of proinflammatory cytokines by the phagocytes

    DNA methylation profiling identifies epigenetic dysregulation in pancreatic islets from type 2 diabetic patients

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    The first genome-scale DNA methylation study on pancreatic islets from type 2 diabetic patients identifies disease-associated DNA methylation pattern that translate into aberrant gene expression in novel factors relevant for β-cell function and survival

    Exposing the DNA methylome iceberg.

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    DNA methylation was the first epigenetic modification discovered. Until recently, comprehensive coverage of the composition and distribution of methylated cytosines across the genome was lacking. Technological advances, however, are providing methylation maps that can reveal the genomic distribution of DNA methylation in different cell states or phenotypes. The emerging picture includes extensive gene body methylation that is highly conserved in eukaryotes, the presence of DNA methylation in previously unappreciated sequence contexts, and the discovery of another modified DNA base, 5-hydroxymethylcytosine. These new data point to the role of DNA methylation both in gene silencing and gene activation; reconciliation of these seemingly contradictory roles will be essential to fully unravel the biological function of DNA methylation in eukaryotes. Here we review how these recently exposed features of the DNA methylome are challenging previously held dogmas in the field.info:eu-repo/semantics/publishe

    Regulation of mammalian DNA methyltransferases: a route to new mechanisms

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    DNA methyltransferases (DNMTs) establish and maintain DNA methylation patterns, contributing to gene regulation. This review explores the current understanding of the pathways that target DNMTs to specific genomic regions and highlights recent findings on the way in which DNMTs are controlled at both the post-transcriptional and post-translational level

    A somatization comorbidity phenotype impacts response to therapy in rheumatoid arthritis: post-hoc results from the certolizumab pegol phase 4 PREDICT trial

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    Abstract Background Comorbidities may contribute to disease activity and treatment response in rheumatoid arthritis (RA) patients. We defined a somatization comorbidity phenotype (SCP) and examined its influence on response to certolizumab pegol (CZP) using data from the PREDICT trial. Methods Patients in PREDICT were randomized to the patient-reported Routine Assessment of Patient Index Data 3 (RAPID3) or physician-based Clinical Disease Activity Index (CDAI) for treatment response assessment. Post-hoc analyses identified patients with the SCP, which included diagnosis of depression, fibromyalgia/myalgias, and/or use of medications indicated for treatment of depression, anxiety, or neuropathic pain. The effect of the SCP on RAPID3 or CDAI response at week 12 and low disease activity (LDA; Disease Activity Score in 28 joints based on erythrocyte sedimentation rate ≤ 3.2) at week 52, in week-12 responders, was analyzed using non-parametric analysis of covariance (ANCOVA). Results At baseline, 43% (313/733) of patients met the SCP classification. Patients with the SCP were 9% more likely to withdraw from the trial. American College of Rheumatology 20% (ACR20), ACR50, and ACR70 responses were 5–14% lower among those with the SCP, and 11% more patients reported adverse events (AEs). Patients without SCP in the CDAI arm were twice as likely to achieve LDA at week 52 compared with those with SCP (32% versus 16%). No differentiation by SCP was observed in the RAPID3 arm (pooled result 21.5%). Conclusions We operationalized a potentially important somatization comorbidity phenotype in a trial setting that was associated with a substantially lower likelihood of treatment response and a higher frequency of AEs. Including large numbers of patients with this phenotype in RA trials may reduce the measured clinical effectiveness of a new molecule. Trial registration ClinicalTrials.gov, NCT01255761. Registered on 6 December 2010

    Nature or nurture: let food be your epigenetic medicine in chronic inflammatory disorders

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    Numerous clinical, physiopathological and epidemiological studies have underlined the detrimental or beneficial role of nutritional factors in complex inflammation related disorders such as allergy, asthma, obesity, type 2 diabetes, cardiovascular disease, rheumatoid arthritis and cancer. Today, nutritional research has shifted from alleviating nutrient deficiencies to chronic disease prevention. It is known that lifestyle, environmental conditions and nutritional compounds influence gene expression. Gene expression states are set by transcriptional activators and repressors and are often locked in by cell-heritable chromatin states. Only recently, it has been observed that the environmental conditions and daily diet can affect transgenerational gene expression via " reversible" heritable epigenetic mechanisms. Epigenetic changes in DNA methylation patterns at CpG sites (epimutations) or corrupt chromatin states of key inflammatory genes and noncoding RNAs, recently emerged as major governing factors in cancer, chronic inflammatory and metabolic disorders. Reciprocally, inflammation, metabolic stress and diet composition can also change activities of the epigenetic machinery and indirectly or directly change chromatin marks. This has recently launched re-exploration of anti-inflammatory bioactive food components for characterization of their effects on epigenome modifying enzymatic activities (acetylation, methylation, phosphorylation, ribosylation, oxidation, ubiquitination, sumoylation). This may allow to improve healthy aging by reversing disease prone epimutations involved in chronic inflammatory and metabolic disorders. © 2010 Elsevier Inc.SCOPUS: re.jinfo:eu-repo/semantics/publishe
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