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| 2. |
- Rangel-Salazar, Ruben, et al.
(författare)
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Human native lipoprotein-induced de novo DNA methylation is associated with repression of inflammatory genes in THP-1 macrophages
- 2011
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Ingår i: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Background: We previously showed that a VLDL-and LDL-rich mix of human native lipoproteins induces a set of repressive epigenetic marks, i. e. de novo DNA methylation, histone 4 hypoacetylation and histone 4 lysine 20 (H4K20) hypermethylation in THP-1 macrophages. Here, we: 1) ask what gene expression changes accompany these epigenetic responses; 2) test the involvement of candidate factors mediating the latter. We exploited genome expression arrays to identify target genes for lipoprotein-induced silencing, in addition to RNAi and expression studies to test the involvement of candidate mediating factors. The study was conducted in human THP-1 macrophages. Results: Native lipoprotein-induced de novo DNA methylation was associated with a general repression of various critical genes for macrophage function, including pro-inflammatory genes. Lipoproteins showed differential effects on epigenetic marks, as de novo DNA methylation was induced by VLDL and to a lesser extent by LDL, but not by HDL, and VLDL induced H4K20 hypermethylation, while HDL caused H4 deacetylation. The analysis of candidate factors mediating VLDL-induced DNA hypermethylation revealed that this response was: 1) surprisingly, mediated exclusively by the canonical maintenance DNA methyltransferase DNMT1, and 2) independent of the Dicer/microRNA pathway. Conclusions: Our work provides novel insights into epigenetic gene regulation by native lipoproteins. Furthermore, we provide an example of DNMT1 acting as a de novo DNA methyltransferase independently of canonical de novo enzymes, and show proof of principle that de novo DNA methylation can occur independently of a functional Dicer/micro-RNA pathway in mammals.
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| 3. |
- Silva-Martínez, Guillermo A., et al.
(författare)
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Arachidonic and oleic acid exert distinct effects on the DNA methylome
- 2016
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Ingår i: Epigenetics. - : Informa UK Limited. - 1559-2294 .- 1559-2308. ; 11:5, s. 321-334
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: Abnormal fatty acid metabolism and availability are landmarks of metabolic diseases, which in turn are associated with aberrant DNA methylation profiles. To understand the role of fatty acids in disease epigenetics, we sought DNA methylation profiles specifically induced by arachidonic (AA) or oleic acid (OA) in cultured cells and compared those with published profiles of normal and diseased tissues. THP-1 monocytes were stimulated with AA or OA and analyzed using Infinium HumanMethylation450 BeadChip (Illumina) and Human Exon 1.0 ST array (Affymetrix). Data were corroborated in mouse embryonic fibroblasts. Comparisons with publicly available data were conducted by standard bioinformatics. AA and OA elicited a complex response marked by a general DNA hypermethylation and hypomethylation in the 1–200 μM range, respectively, with a maximal differential response at the 100 μM dose. The divergent response to AA and OA was prominent within the gene body of target genes, where it correlated positively with transcription. AA-induced DNA methylation profiles were similar to the corresponding profiles described for palmitic acid, atherosclerosis, diabetes, obesity, and autism, but relatively dissimilar from OA-induced profiles. Furthermore, human atherosclerosis grade-associated DNA methylation profiles were significantly enriched in AA-induced profiles. Biochemical evidence pointed to β-oxidation, PPAR-α, and sirtuin 1 as important mediators of AA-induced DNA methylation changes. In conclusion, AA and OA exert distinct effects on the DNA methylome. The observation that AA may contribute to shape the epigenome of important metabolic diseases, supports and expands current diet-based therapeutic and preventive efforts.
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| 4. |
- Zaina, Silvio, et al.
(författare)
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A DNA Methylation Map of Human Atherosclerosis.
- 2014
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Ingår i: Circulation: Cardiovascular Genetics. - 1942-325X. ; 7:5, s. 692-700
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Tidskriftsartikel (refereegranskat)abstract
- -Epigenetic alterations may contribute to the development of atherosclerosis. In particular, DNA methylation, a reversible and highly regulated DNA modification, could influence disease onset and progression since it functions as an effector for environmental influences, including diet and lifestyle, both of which are risk factors for cardiovascular diseases.
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| 7. |
- Zaina, Silvio, et al.
(författare)
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Dynamic epigenetic age mosaicism in the human atherosclerotic artery
- 2022
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 17:6 June
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Tidskriftsartikel (refereegranskat)abstract
- Accelerated epigenetic ageing, a promising marker of disease risk, has been detected in peripheral blood cells of atherosclerotic patients, but evidence in the vascular wall is lacking. Understanding the trends of epigenetic ageing in the atheroma may provide insights into mechanisms of atherogenesis or identify targets for molecular therapy. We surveyed DNA methylation age in two human artery samples: a set of donor-matched, paired atherosclerotic and healthy aortic portions, and a set of carotid artery atheromas. The well-characterized pan-tissue Horvath epigenetic clock was used, together with the Weidner whole-blood-specific clock as validation. For the first time, we document dynamic DNA methylation age mosaicism of the vascular wall that is atherosclerosis-related, switches from acceleration to deceleration with chronological ageing, and is consistent in human aorta and carotid atheroma. At CpG level, the Horvath epigenetic clock showed modest differential methylation between atherosclerotic and healthy aortic portions, weak association with atheroma histological grade and no clear evidence for participation in atherosclerosis-related cellular pathways. Our data suggest caution when assigning a unidirectional DNA methylation age change to the atherosclerotic arterial wall. Also, the results support previous conclusions that epigenetic ageing reflects non-disease-specific cellular alterations.
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| 9. |
- Zaina, Silvio, et al.
(författare)
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Insulin-like growth factor II plays a central role in atherosclerosis in a mouse model.
- 2002
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Ingår i: Journal of Biological Chemistry. - 1083-351X .- 0021-9258. ; 277:6, s. 4505-4511
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Tidskriftsartikel (refereegranskat)abstract
- Insulin-like growth factor II is a fetal promoter of cell proliferation that is involved in some forms of cancer and overgrowth syndromes in humans. Here, we provide two sources of genetic evidence for a novel, pivotal role of locally produced insulin-like growth factor II in the development of atherosclerosis. First, we show that homozygosity for a disrupted insulin-like growth factor II allele in mice lacking apolipoprotein E, a widely used animal model of atherosclerosis, results in aortic lesions that are approximately 80% smaller and contain approximately 50% less proliferating cells compared with mice lacking only apolipoprotein E. Second, targeted expression of an insulin-like growth factor II transgene in smooth muscle cells, but not the mere elevation of circulating levels of the peptide, causes per se aortic focal intimal thickenings. The insulin-like growth factor II transgenics presented here are the first viable mutant mice spontaneously developing intimal masses. These observations provide the first direct evidence for an atherogenic activity of insulin-like growth factor II in vivo.
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| 10. |
- Zaina, Silvio, et al.
(författare)
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Nutrition and aberrant DNA methylation patterns in atherosclerosis: More than just hyperhomocysteinemia?
- 2005
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Ingår i: Journal of Nutrition. - 1541-6100. ; 135:1, s. 5-8
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Tidskriftsartikel (refereegranskat)abstract
- Methylation is a reversible modification of DNA participating in epigenetic regulation of gene expression. It is now clear that atherosclerosis is associated with aberrant DNA methylation patterns in the vascular tissue and peripheral blood cells, but the origin of this anomaly is poorly understood. Based on evidence that global DNA hypomethylation coexists with hyperhomocysteinemia in advanced human atherosclerosis, it is widely assumed that altered DNA methylation patterns in atherosclerosis are mainly secondary to a decrease in factors essential for the synthesis of S-adenosyl methionine (SAM, the main methyl group donor in DNA methylation reactions), such as folate and vitamin B-12, or to homocysteine-induced blocking of SAM biosynthesis. Nonetheless, recent work expanded this view by showing that both local DNA hyper- and hypomethylation occur in early atherosclerosis in normohomocysteinemic mice and that atherogenic lipoprotein profiles promote DNA hypermethylation in cultured human macrophages. These findings suggest that during early atherosclerosis, nutritional factors affect DNA methylation patterns by mechanisms that are likely to be independent of vitamin or homocysteine levels. These data have the potential to assist in the identification of preventive or therapeutic avenues for cardiovascular disease.
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