| 1. |
- Aavik, Einari, et al.
(författare)
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Global DNA methylation analysis of human atherosclerotic plaques reveals extensive genomic hypomethylation and reactivation at imprinted locus 14q32 involving induction of a miRNA cluster
- 2015
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 36:16, s. 993-U23
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Tidskriftsartikel (refereegranskat)abstract
- Aims Genetics can explain just above 10% of the observed heritability in cardiovascular diseases. Epigenetics is about to provide some further explanations, but the information needed for that is in the accumulation phase. Genome-wide DNA methylation analysis has revealed thousands of genes, which are epigenetically differentially regulated in atherosclerotic plaques. Our results point to an additional level of complexity that needs to be integrated into the aetiology of atherogenesis.We conducted a genome-wide analysis to identify differentially methylated genes in atherosclerotic lesions. Methods DNA methylation at promoters, exons and introns was identified by massive parallel sequencing. Gene expression was analysed by microarrays, qPCR, immunohistochemistry and western blots. Results Globally, hypomethylation of chromosomal DNA predominates in atherosclerotic plaques and two-thirds of genes showing over 2.5-fold differential in DNA methylation are up-regulated in comparison to healthy mammary arteries. The imprinted chromatin locus 14q32 was identified for the first time as an extensively hypomethylated area in atherosclerosis with highly induced expression of miR127, -136, -410, -431, -432, -433 and capillary formation-associated gene RTL1. The top 100 list of hypomethylated promoters exhibited over 1000-fold enrichment for miRNAs, many of which mapped to locus 14q32. Unexpectedly, also gene body hypermethylation was found to correlate with stimulated mRNA expression. Conclusion Significant changes in genomic methylation were identified in atherosclerotic lesions. The most prominent gene cluster activated via hypomethylation was detected at imprinted chromosomal locus 14q32 with several clustered miRNAs that were up-regulated. These results suggest that epigenetic changes are involved in atherogenesis and may offer new potential therapeutic targets for vascular diseases.
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| 2. |
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| 3. |
- Gallini, Radiosa, et al.
(författare)
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Isoform-Specific Modulation of Inflammation Induced by Adenoviral Mediated Delivery of Platelet-Derived Growth Factors in the Adult Mouse Heart
- 2016
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:8
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Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factors (PDGFs) are key regulators of mesenchymal cells in vertebrate development. To what extent PDGFs also exert beneficial homeostatic or reparative roles in adult organs, as opposed to adverse fibrogenic responses in pathology, are unclear. PDGF signaling plays critical roles during heart development, during which forced overexpression of PDGFs induces detrimental cardiac fibrosis; other studies have implicated PDGF signaling in post-infarct myocardial repair. Different PDGFs may exert different effects mediated through the two PDGF receptors (PDGFR alpha and PDGFR beta) in different cell types. Here, we assessed responses induced by five known PDGF isoforms in the adult mouse heart in the context of adenovirus vector-mediated inflammation. Our results show that different PDGFs have different, in some cases even opposing, effects. Strikingly, whereas the major PDGFRa agonists (PDGF-A and -C) decreased the amount of scar tissue and increased the numbers of PDGFR alpha-positive fibroblasts, PDGFR beta agonists either induced large scars with extensive inflammation (PDGF-B) or dampened the adenovirusinduced inflammation and produced a small and dense scar (PDGF-D). These results provide evidence for PDGF isoform-specific inflammation-modulating functions that may have therapeutic implications. They also illustrate a surprising complexity in the PDGF-mediated pathophysiological responses.
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| 4. |
- Hytonen, Jarkko P., et al.
(författare)
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Local adventitial anti-angiogenic gene therapy reduces growth of vasa-vasorum and in-stent restenosis in WHHL rabbits
- 2018
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Ingår i: Journal of Molecular and Cellular Cardiology. - : ELSEVIER SCI LTD. - 0022-2828 .- 1095-8584. ; 121, s. 145-154
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Tidskriftsartikel (refereegranskat)abstract
- Background: Antiproliferative drugs in drug eluting stents (DES) are associated with complications due to impaired re-endothelialization. Additionally, adventitial neovascularization has been suggested to contribute to in-stent restenosis (ISR). Since Vascular Endothelial Growth Factors (VEGFs) are the key mediators of angiogenesis, we investigated feasibility and efficacy of local gene therapy for ISR utilizing soluble decoy VEGF receptors to reduce biological activity of adventitial VEGFs.Method: Sixty-nine adult WHHL rabbit aortas were subjected to endothelial denudation. Six weeks later catheter-mediated local intramural infusion of 1.5x10e10 pfu adenoviruses encoding soluble VEGF Receptor-1 (sVEGFR1), sVEGFR2, sVEGFR3 or control LacZ and bare metal stent implantation were performed in the same aortic segment. Marker protein expression was assessed at 6d in LacZ cohort. Immunohistochemistry, morphometrical analyses and angiography were performed at d14, d42 and d90.Results: Transgene expression was localized to adventitia. All decoy receptors reduced the size of vasa-vasorum at 14d, AdsVEGFR2 animals also had reduced density of adventitial vasa-vasorum, whereas AdsVEGFR3 increased the density of vasa-vasorum. At d42, AdsVEGFR1 and AdsVEGFR2 reduced ISR (15.7 +/- 6.9% stenosis, P < 0.01 and 16.5 +/- 2.7%, P < 0.05, respectively) vs. controls (28.3 +/- 7.6%). Moreover, AdsVEGFR-3 treatment led to a non-significant trend in the reduction of adventitial lymphatics at all time points and these animals had significantly more advanced neointimal atherosclerosis at 14d and 42d vs. control animals.Conclusions: Targeting adventitial neovascularization using sVEGFR1 and sVEGFR2 is a novel strategy to reduce ISR. The therapeutic effects dissipate at late follow up following short expression profile of adenoviral vectors. However, inhibition of VEGFR3 signaling accelerates neoatherosclerosis.
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| 5. |
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| 6. |
- Kalén, Mattias, et al.
(författare)
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Gamma-Secretase Inhibitor Treatment Promotes VEGF-A-Driven Blood Vessel Growth and Vascular Leakage but Disrupts Neovascular Perfusion
- 2011
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:4, s. e18709-
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Tidskriftsartikel (refereegranskat)abstract
- The Notch signaling pathway is essential for normal development due to its role in control of cell differentiation, proliferation and survival. It is also critically involved in tumorigenesis and cancer progression. A key enzyme in the activation of Notch signaling is the gamma-secretase protein complex and therefore, gamma-secretase inhibitors (GSIs)originally developed for Alzheimer's disease-are now being evaluated in clinical trials for human malignancies. It is also clear that Notch plays an important role in angiogenesis driven by Vascular Endothelial Growth Factor A (VEGF-A)-a process instrumental for tumor growth and metastasis. The effect of GSIs on tumor vasculature has not been conclusively determined. Here we report that Compound X (CX), a GSI previously reported to potently inhibit Notch signaling in vitro and in vivo, promotes angiogenic sprouting in vitro and during developmental angiogenesis in mice. Furthermore, CX treatment suppresses tumor growth in a mouse model of renal carcinoma, leads to the formation of abnormal vessels and an increased tumor vascular density. Using a rabbit model of VEGF-A-driven angiogenesis in skeletal muscle, we demonstrate that CX treatment promotes abnormal blood vessel growth characterized by vessel occlusion, disrupted blood flow, and increased vascular leakage. Based on these findings, we propose a model for how GSIs and other Notch inhibitors disrupt tumor blood vessel perfusion, which might be useful for understanding this new class of anti-cancer agents.
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| 7. |
- Niittykoski, Minna, et al.
(författare)
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Immunohistochemical Characterization and Sensitivity to Human Adenovirus Serotypes 3, 5, and 11p of New Cell Lines Derived from Human Diffuse Grade II to IV Gliomas
- 2017
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Ingår i: Translational Oncology. - : ELSEVIER SCIENCE INC. - 1944-7124 .- 1936-5233. ; 10:5, s. 772-779
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Oncolytic adenoviruses show promise in targeting gliomas because they do not replicate in normal brain cells. However, clinical responses occur only in a subset of patients. One explanation could be the heterogenic expression level of virus receptors. Another contributing factor could be variable activity of tumor antiviral defenses in different glioma subtypes. METHODS: We established a collection of primary low-passage cell lines from different glioma subtypes (3 glioblastomas, 3 oligoastrocytomas, and 2 oligodendrogliomas) and assessed them for receptor expression and sensitivity to human adenovirus (HAd) serotypes 3, 5, and 11p. To gauge the impact of antiviral defenses, we also compared the infectivity of the oncolytic adenoviruses in interferon (IFN)-pretreated cells with IFN-sensitive Semliki Forest virus (SFV). RESULTS: Immunostaining revealed generally low expression of HAd5 receptor CAR in both primary tumors and derived cell lines. HAd11p receptor CD46 levels were maintained at moderate levels in both primary tumor samples and derived cell lines. HAd3 receptor DSG-2 was reduced in the cell lines compared to the tumors. Yet, at equal multiplicities of infection, the oncolytic potency of HAd5 in vitro in tumor-derived cells was comparable to HAd11p, whereas HAd3 lysed fewer cells than either of the other two HAd serotypes in 72 hours. IFN blocked replication of SFV, while HAds were rather unaffected. CONCLUSIONS: Adenovirus receptor levels on glioma-derived cell lines did not correlate with infection efficacy and may not be a relevant indicator of clinical oncolytic potency. Adenovirus receptor analysis should be preferentially performed on biopsies obtained perioperatively.
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| 8. |
- Nowak-Sliwinska, Patrycja, et al.
(författare)
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Consensus guidelines for the use and interpretation of angiogenesis assays
- 2018
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Ingår i: Angiogenesis. - : Springer. - 0969-6970 .- 1573-7209. ; 21:3, s. 425-532
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Forskningsöversikt (refereegranskat)abstract
- The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference.
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| 9. |
- Rissanen, Tuomas T., et al.
(författare)
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The bottleneck stent model for chronic myocardial ischemia and heart failure in pigs
- 2013
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Ingår i: American Journal of Physiology. Heart and Circulatory Physiology. - : American Physiological Society. - 0363-6135 .- 1522-1539. ; 305:9, s. H1297-H1308
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Tidskriftsartikel (refereegranskat)abstract
- A large animal model of chronic myocardial ischemia and heart failure is crucial for the development of novel therapeutic approaches. In this study we developed a novel percutaneous one-and two-vessel model for chronic myocardial ischemia using a stent coated with a polytetrafluoroethylene tube formed in a bottleneck shape. The bottleneck stent was implanted in the proximal left anterior descending (LAD) or proximal circumflex artery (LCX), or in both proximal LCX and mid LAD 1 wk later (2-vessel model), and pigs were followed for 4-5 wk. Ejection fraction (EF), infarct size, collateral growth, and myocardial perfusion were assessed. Pigs were given antiarrhythmic medication to prevent sudden death. The occlusion time of the bottleneck stent and the timing of myocardial infarction could be modulated by the duration of antiplatelet medication. Fractional flow reserve measurements and positron emission tomography imaging showed severe ischemia after bottleneck stenting covering over 50% of the left ventricle in the proximal LAD model. Complete coronary occlusion was necessary for significant collateral growth, which mostly had occurred already during the first wk after the stent occlusion. Dynamic and competitive collateral growth patterns were observed. EF declined from 64 to 41% in the LCX model and to 44% in the LAD model 4 wk after stenting with 12 and 21% infarcted left ventricle in the LCX and LAD models, respectively. The mortality was 32 and 37% in the LCX and LAD models but very (71%) high in the two-vessel disease model. The implantation of a novel bottleneck stent in the proximal LAD or LCX is a novel porcine model of reversible myocardial ischemia (open stent) and ischemic heart failure (occluded stent) and is feasible for the development of new therapeutic approaches.
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| 10. |
- Zhang, Fan, et al.
(författare)
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VEGF-B is dispensable for blood vessel growth but critical for their survival, and VEGF-B targeting inhibits pathological angiogenesis
- 2009
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 106:15, s. 6152-6157
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Tidskriftsartikel (refereegranskat)abstract
- VEGF-B, a homolog of VEGF discovered a long time ago, has not been considered an important target in antiangiogenic therapy. Instead, it has received little attention from the field. In this study, using different animal models and multiple types of vascular cells, we revealed that although VEGF-B is dispensable for blood vessel growth, it is critical for their survival. Importantly, the survival effect of VEGF-B is not only on vascular endothelial cells, but also on pericytes, smooth muscle cells, and vascular stem/progenitor cells. In vivo, VEGF-B targeting inhibited both choroidal and retinal neovascularization. Mechanistically, we found that the vascular survival effect of VEGF-B is achieved by regulating the expression of many vascular prosurvival genes via both NP-1 and VEGFR-1. Our work thus indicates that the function of VEGF-B in the vascular system is to act as a "survival," rather than an "angiogenic" factor and that VEGF-B inhibition may offer new therapeutic opportunities to treat neovascular diseases.
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