| 1. |
- Edger, Patrick P., et al.
(författare)
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The butterfly plant arms-race escalated by gene and genome duplications
- 2015
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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. ; 112:27, s. 8362-8366
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Tidskriftsartikel (refereegranskat)abstract
- Coevolutionary interactions are thought to have spurred the evolution of key innovations and driven the diversification of much of life on Earth. However, the genetic and evolutionary basis of the innovations that facilitate such interactions remains poorly understood. We examined the coevolutionary interactions between plants (Brassicales) and butterflies (Pieridae), and uncovered evidence for an escalating evolutionary arms-race. Although gradual changes in trait complexity appear to have been facilitated by allelic turnover, key innovations are associated with gene and genome duplications. Furthermore, we show that the origins of both chemical defenses and of molecular counter adaptations were associated with shifts in diversification rates during the arms-race. These findings provide an important connection between the origins of biodiversity, coevolution, and the role of gene and genome duplications as a substrate for novel traits.
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| 2. |
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| 3. |
- Arpaia, Riccardo, 1985, et al.
(författare)
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Engineering underdoped CuO2 nanoribbons in nm-thick a -axis YBa2Cu3 O7-δ films
- 2024
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Ingår i: Physical Review Materials. - 2475-9953. ; 8:4
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Tidskriftsartikel (refereegranskat)abstract
- In underdoped cuprate high-Tc superconductors, various local orders and symmetry-breaking states, in addition to superconductivity, reside in the CuO2 planes. The confinement of the CuO2 planes can therefore play a fundamental role in modifying the hierarchy between the various orders and their intertwining with superconductivity. Here we present the growth of a-axis oriented YBa2Cu3O7-δ films, spanning the whole underdoped side of the phase diagram. In these samples, the CuO2 planes are confined by the film thickness, effectively forming unit-cell-thick nanoribbons. The unidirectional confinement at the nanoscale enhances the in-plane anisotropy of the films. By x-ray diffraction and resistance vs temperature measurements, we have discovered the suppression of the orthorhombic-to-tetragonal transition at low dopings, and a very high anisotropy of the normal state resistance in the b-c plane, the latter being connected to a weak coupling between adjacent CuO2 nanoribbons. These findings show that the samples we have grown represent a novel system, different from the bulk, where future experiments can possibly shed light on the rich and mysterious physics occurring within the CuO2 planes.
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| 4. |
- Arpaia, Riccardo, 1985, et al.
(författare)
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Engineering underdoped CuO2 nanoribbons in nm-thick a -axis YBa2Cu3 O7-δ films
- 2024
-
Ingår i: Physical Review Materials. - : American Physical Society. - 2475-9953. ; 8:4
-
Tidskriftsartikel (refereegranskat)abstract
- In underdoped cuprate high-Tc superconductors, various local orders and symmetry-breaking states, in addition to superconductivity, reside in the CuO2 planes. The confinement of the CuO2 planes can therefore play a fundamental role in modifying the hierarchy between the various orders and their intertwining with superconductivity. Here we present the growth of a-axis oriented YBa2Cu3O7-δ films, spanning the whole underdoped side of the phase diagram. In these samples, the CuO2 planes are confined by the film thickness, effectively forming unit-cell-thick nanoribbons. The unidirectional confinement at the nanoscale enhances the in-plane anisotropy of the films. By x-ray diffraction and resistance vs temperature measurements, we have discovered the suppression of the orthorhombic-to-tetragonal transition at low dopings, and a very high anisotropy of the normal state resistance in the b-c plane, the latter being connected to a weak coupling between adjacent CuO2 nanoribbons. These findings show that the samples we have grown represent a novel system, different from the bulk, where future experiments can possibly shed light on the rich and mysterious physics occurring within the CuO2 planes.
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| 5. |
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| 6. |
- Bergqvist, Davis, et al.
(författare)
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Benartärsjukdom – inget nytt sedan SBU-rapporten
- 2011
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Ingår i: Läkartidningen. - : Läkartidningen Förlag. - 0023-7205 .- 1652-7518. ; 108:8, s. 403-405
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Huvudresultaten i SBU:s benischemirapport sammanfattas.Inga nya studier av öppna eller endovaskulära behandlingsmetoder har nämnvärt förändrat behandlingsstragegin vid benartärsjukdom.Ett läkemedel – cilostazol – har godkänts för symtomatisk behandling vid claudicatio intermittens.Kontrollerade studier pågår för att lokalt stimulera kärlnybildning i ischemisk muskulatur.
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| 7. |
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| 8. |
- Cao, Ziquan, et al.
(författare)
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Hypoxia-induced retinopathy model in adult zebrafish
- 2010
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Ingår i: Nature Protocols. - : Nature Publishing Group. - 1754-2189 .- 1750-2799. ; 5:12, s. 1903-1910
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Tidskriftsartikel (refereegranskat)abstract
- Hypoxia-induced vascular responses, including angiogenesis, vascular remodeling and vascular leakage, significantly contribute to the onset, development and progression of retinopathy. However, until recently there were no appropriate animal disease models recapitulating adult retinopathy available. In this article, we describe protocols that create hypoxia-induced retinopathy in adult zebrafish. Adult fli1: EGFP zebrafish are placed in hypoxic water for 3-10 d and retinal neovascularization is analyzed using confocal microscopy. It usually takes 11 d to obtain conclusive results using the hypoxia-induced retinopathy model in adult zebrafish. This model provides a unique opportunity to study kinetically the development of retinopathy in adult animals using noninvasive protocols and to assess therapeutic efficacy of orally active antiangiogenic drugs.
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| 9. |
- Cao, Ziquan, 1982-
(författare)
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VEGF-mediated vascular functions in health and disease
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Angiogenesis is essential for physiological processes including embryonic development, tissue regeneration, and reproduction. Under various pathological conditions the same angiogenic process contribute to the onset, development, and progression of many human diseases including cancer, diabetic complications, ocular disease, chronic inflammation and cardiovascular disease. Vascular endothelial growth factor (VEGF) is a key angiogenic factor for physiological and pathological angiogenesis. In addition to its strong angiogenic activity, VEGF also potently induces vascular permeability, often causing tissue edema in various pathological tissues. VEGF transduces its vascular signal through two tyrosine kinase receptors-VEGFR1 and VEGFR2, the latter being a functional receptor that mediates both angiogenic and vascular permeability effects. To study physiological and pathological functions of VEGF, we developed novel zebrafish disease models that permit us to study hypoxia-induced retinopathy and cancer metastasis processes. We have also administered anti-VEGF and anti-VEGFR specific antibodies to healthy mice to study the homeostatic role of VEGF in the maintenance of vascular integrity and its functions in various tissues and organs.Finally, using a zebrafish model, we evaluated if VEGF expression is regulated by circadian clock genes. In paper I, we developed protocols that create hypoxia-induced retinopathy in adult zebrafish. Adult fli1:EGFP zebrafish were placed in hypoxic water for 3-10 days with retinal neovascularization being analyzed using confocal microscopy. This model provides a unique opportunity to kinetically study the development of retinopathy in adult animals using non-invasive protocols and to assess the therapeutic efficacy of orally administered anti-angiogenic drugs. In paper II, we developed a zebrafish metastasis model to dissect the complex events of hypoxia-induced tumor cell invasion and metastasis in association with angiogenesis at the single-cell level. In this model, fluorescent DiI-labeled human or mouse tumor cells were implanted into the perivitelline cavity of 48-hour-old zebrafish embryos, which were subsequently placed in hypoxic water for 3 days. Tumor cell invasion, metastasis and pathological angiogenesis were analyzed using fluorescent microscopy in the living fish. The average experimental time for this model is 7 days. Our protocol offers an opportunity to study molecular mechanisms of hypoxia-induced cancer metastasis. In paper III, we show that systemic delivery of an anti-VEGF or an anti-VEGF receptor (VEGFR)-2 neutralizing antibody cause global vascular regression in mice. Among all examined tissues, the vasculature in endocrine glands, intestinal villi, and the uterus are most affected in response to VEGF or VEGFR-2 blockades. Pro-longed anti-VEGF treatment resulted in a significant decrease in the circulating levels of the predominant thyroid hormone, free thyroxine, but not the minimal isoform of triiodothyronine, suggesting that chronic anti-VEGF treatment impairs thyroid function. These findings provide structural and functional bases of anti-VEGF-specific druginduced side effects in relation to vascular changes in healthy tissues. In paper IV, we show that disruption of the circadian clock by constant exposure to light coupled with genetic manipulation of key genes in the zebrafish led to impaired developmental angiogenesis. A bmal1-specific morpholino inhibited developmental angiogenesis in zebrafish embryos without causing obvious nonvascular phenotypes. Conversely, a period2 morpholino accelerated angiogenic vessel growth, suggesting that Bmal1 and Period2 display opposing angiogenic effects. These results offer mechanistic insights into the role of the circadian clock in regulation of developmental angiogenesis, and our findings may be reasonably extended to other types of physiological or pathological angiogenesis. Overall, the results in this thesis provide further insight to angiogenic mechanistic properties in tissues and suggest possible novel therapeutic targets for the treatment of various angiogenesis-dependent diseases.
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| 10. |
- Dahl Jensen, Lasse, et al.
(författare)
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Opposing Effects of Circadian Clock Genes Bmal1 and Period2 in Regulation of VEGF-Dependent Angiogenesis in Developing Zebrafish
- 2012
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Ingår i: Cell Reports. - : Elsevier (Cell Press). - 2211-1247. ; 2:2, s. 231-241
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Tidskriftsartikel (refereegranskat)abstract
- Molecular mechanisms underlying circadian-regulated physiological processes remain largely unknown. Here, we show that disruption of the circadian clock by both constant exposure to light and genetic manipulation of key genes in zebrafish led to impaired developmental angiogenesis. A bmal1-specific morpholino inhibited developmental angiogenesis in zebrafish embryos without causing obvious nonvascular phenotypes. Conversely, a period2 morpholino accelerated angiogenic vessel growth, suggesting that Bmal1 and Period2 display opposing angiogenic effects. Using a promoter-reporter system consisting of various deleted vegf-promoter mutants, we show that Bmal1 directly binds to and activates the vegf promoter via E-boxes. Additionally, we provide evidence that knockdown of Bmal1 leads to impaired Notch-inhibition-induced vascular sprouting. These results shed mechanistic insight on the role of the circadian clock in regulation of developmental angiogenesis, and our findings may be reasonably extended to other types of physiological or pathological angiogenesis.
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