| 1. |
- Cao, Renhai, et al.
(författare)
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Collaborative interplay between FGF-2 and VEGF-C promotes lymphangiogenesis and metastasis
- 2012
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 109:39, s. 15894-15899
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Tidskriftsartikel (refereegranskat)abstract
- Interplay between various lymphangiogenic factors in promoting lymphangiogenesis and lymphatic metastasis remains poorly understood. Here we show that FGF-2 and VEGF-C, two lymphangiogenic factors, collaboratively promote angiogenesis and lymphangiogenesis in the tumor microenvironment, leading to widespread pulmonary and lymph-node metastases. Coimplantation of dual factors in the mouse cornea resulted in additive angiogenesis and lymphangiogenesis. At the molecular level, we showed that FGFR-1 expressed in lymphatic endothelial cells is a crucial receptor that mediates the FGF-2-induced lymphangiogenesis. Intriguingly, the VEGFR-3-mediated signaling was required for the lymphatic tip cell formation in both FGF-2- and VEGF-C-induced lymphangiogenesis. Consequently, a VEGFR-3-specific neutralizing antibody markedly inhibited FGF-2-induced lymphangiogenesis. Thus, the VEGFR-3-induced lymphatic endothelial cell tip cell formation is a prerequisite for FGF-2-stimulated lymphangiogenesis. In the tumor microenvironment, the reciprocal interplay between FGF-2 and VEGF-C collaboratively stimulated tumor growth, angiogenesis, intratumoral lymphangiogenesis, and metastasis. Thus, intervention and targeting of the FGF-2- and VEGF-C-induced angiogenic and lymphangiogenic synergism could be potentially important approaches for cancer therapy and prevention of metastasis.
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| 2. |
- Cao, Renhai, et al.
(författare)
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Mouse corneal lymphangiogenesis model.
- 2011
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Ingår i: Nature protocols. - : Springer Science and Business Media LLC. - 1750-2799 .- 1754-2189. ; 6:6, s. 817-26
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Tidskriftsartikel (refereegranskat)abstract
- This protocol describes a powerful in vivo method to quantitatively study the formation of new lymphatic vessels in the avascular cornea without interference of pre-existing lymphatics. Implantation of 100 ng of lymphangiogenic factors such as vascular endothelial growth factor (VEGF)-A, VEGF-C or fibroblast growth factor-2, together with slow-release polymers, into a surgically created micropocket in the mouse cornea elicits a robust lymphangiogenic response. Newly formed lymphatic vessels are detected by immunohistochemical staining of the flattened corneal tissue with lymphatic endothelial-specific markers such as lymphatic vessel endothelial hyaluronan receptor-1; less-specific markers such as vascular endothelial growth factor receptor 3 may also be used. Lymphatic vessel growth in relation to hemangiogenesis can be readily detected starting at day 5 or 6 after pellet implantation and persists for ∼14 d. This protocol offers a unique opportunity to study the mechanisms underlying lymphatic vessel formation, remodeling and function.
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| 3. |
- 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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| 4. |
- 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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| 5. |
- Dahl Jensen, Lasse, et al.
(författare)
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Zebrafish Models to Study Hypoxia-Induced Pathological Angiogenesis in Malignant and Nonmalignant Diseases
- 2011
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Ingår i: Birth Defects Research. Part C: Embryo Today Reviews. - : John Wiley and Sons.Ltd. - 1542-975X .- 1542-9768. ; 93:2, s. 182-193
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Forskningsöversikt (refereegranskat)abstract
- Most in vivo preclinical disease models are based on mouse and other mammalian systems. However, these rodent-based model systems have considerable limitations to recapitulate clinical situations in human patients. Zebrafish have been widely used to study embryonic development, behavior, tissue regeneration, and genetic defects. Additionally, zebrafish also provides an opportunity to screen chemical compounds that target a specific cell population for drug development. Owing to the availability of various genetically manipulated strains of zebrafish, immune privilege during early embryonic development, transparency of the embryos, and easy and precise setup of hypoxia equipment, we have developed several disease models in both embryonic and adult zebrafish, focusing on studying the role of angiogenesis in pathological settings. These zebrafish disease models are complementary to the existing mouse models, allowing us to study clinically relevant processes in cancer and nonmalignant diseases, which otherwise would be difficult to study in mice. For example, dissemination and invasion of single human or mouse tumor cells from the primary site in association with tumor angiogenesis can be studied under normoxia or hypoxia in zebrafish embryos. Hypoxia-induced retinopathy in the adult zebrafish recapitulates the clinical situation of retinopathy development in diabetic patients or age-related macular degeneration. These zebrafish disease models offer exciting opportunities to understand the mechanisms of disease development, progression, and development of more effective drugs for therapeutic intervention.
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| 6. |
- Dong, Mei, et al.
(författare)
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Cold Exposure Promotes Atherosclerotic Plaque Growth and Instability via UCP1-Dependent Lipolysis
- 2013
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Ingår i: Cell Metabolism. - : Elsevier (Cell Press). - 1550-4131 .- 1932-7420. ; 18:1, s. 118-129
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Tidskriftsartikel (refereegranskat)abstract
- Molecular mechanisms underlying the cold-associated high cardiovascular risk remain unknown. Here, we show that the cold-triggered food-intake-independent lipolysis significantly increased plasma levels of small low-density lipoprotein (LDL) remnants, leading to accelerated development of atherosclerotic lesions in mice. In two genetic mouse knockout models (apolipoprotein E-/- [ApoE(-/-)] and LDL receptor(-/-) [Ldlr(-/-)] mice), persistent cold exposure stimulated atherosclerotic plaque growth by increasing lipid deposition. Furthermore, marked increase of inflammatory cells and plaque-associated microvessels were detected in the cold-acclimated ApoE(-/-) and Ldlr(-/-) mice, leading to plaque instability. Deletion of uncoupling protein 1 (UCP1), a key mitochondrial protein involved in thermogenesis in brown adipose tissue (BAT), in the ApoE(-/-) strain completely protected mice from the cold-induced atherosclerotic lesions. Cold acclimation markedly reduced plasma levels of adiponectin, and systemic delivery of adiponectin protected ApoE(-/-) mice from plaque development. These findings provide mechanistic insights on low-temperature-associated cardiovascular risks.
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| 7. |
- Ji, Hong, et al.
(författare)
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TNFR1 mediates TNF-alpha-induced tumour lymphangiogenesis and metastasis by modulating VEGF-C-VEGFR3 signalling
- 2014
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Ingår i: Nature Communications. - : Nature Publishing Group: Nature Communications. - 2041-1723. ; 5:4944
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Tidskriftsartikel (refereegranskat)abstract
- Inflammation and lymphangiogenesis are two cohesively coupled processes that promote tumour growth and invasion. Here we report that TNF-alpha markedly promotes tumour lymphangiogenesis and lymphatic metastasis. The TNF-alpha-TNFR1 signalling pathway directly stimulates lymphatic endothelial cell activity through a VEGFR3-independent mechanism. However, VEGFR3-induced lymphatic endothelial cell tips are a prerequisite for lymphatic vessel growth in vivo, and a VEGFR3 blockade completely ablates TNF-alpha-induced lymphangiogenesis. Moreover, TNF-alpha-TNFR1-activated inflammatory macrophages produce high levels of VEGF-C to coordinately activate VEGFR3. Genetic deletion of TNFR1 (Tnfr1(-/-)) in mice or depletion of tumour-associated macrophages (TAMs) virtually eliminates TNF-alpha-induced lymphangiogenesis and lymphatic metastasis. Gain-of-function experiments show that reconstitution of Tnfr1(+/+) macrophages in Tnfr1(+/+) mice largely restores tumour lymphangiogenesis and lymphatic metastasis. These findings shed mechanistic light on the intimate interplay between inflammation and lymphangiogenesis in cancer metastasis, and propose therapeutic intervention of lymphatic metastasis by targeting the TNF-alpha-TNFR1 pathway.
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| 8. |
- Lim, Sharon, et al.
(författare)
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Cold-induced activation of brown adipose tissue and adipose angiogenesis in mice
- 2012
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Ingår i: Nature Protocols. - : Nature Publishing Group. - 1754-2189 .- 1750-2799. ; 7:3, s. 606-615
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Tidskriftsartikel (refereegranskat)abstract
- Exposure of humans and rodents to cold activates thermogenic activity in brown adipose tissue (BAT). This protocol describes a mouse model to study the activation of BAT and angiogenesis in adipose tissues by cold acclimation. After a 1-week exposure to 4 degrees C, adult C57BL/6 mice show an obvious transition from subcutaneous white adipose tissue (WAT) into brown-like adipose tissue (BRITE). The BRITE phenotype persists after continuous cold exposure, and by the end of week 5 BRITE contains a high number of uncoupling protein-1-positive mitochondria, a characteristic feature of BAT. During the transition from WAT into BRITE, the vascular density is markedly increased owing to the activation of angiogenesis. In BAT, cold exposure stimulates thermogenesis by increasing the mitochondrial content and metabolic rate. BAT and the increased metabolic rate result in a lean phenotype. This protocol provides an outstanding opportunity to study the molecular mechanisms that control adipose mass.
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| 9. |
- Religa, Piotr, et al.
(författare)
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VEGF significantly restores impaired memory behavior in Alzheimers mice by improvement of vascular survival
- 2013
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Ingår i: Scientific Reports. - : Nature Publishing Group: Open Access Journals - Option B / Nature Publishing Group. - 2045-2322. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- The functional impact of amyloid peptides (Abs) on the vascular system is less understood despite these pathologic peptides are substantially deposited in the brain vasculature of Alzheimers patients. Here we show substantial accumulation of Abs 40 and 42 in the brain arterioles of Alzheimers patients and of transgenic Alzheimers mice. PurifiedAbs 1-40 and 1-42 exhibited vascular regression activity in the in vivo animal models and vessel density was reversely correlated with numbers and sizes of amyloid plaques in human patients. A significant high number of vascular cells underwent cellular apoptosis in the brain vasculature of Alzheimers patients. VEGF significantly prevented Ab-induced endothelial apoptosis in vitro. Neuronal expression of VEGF in transgenic mice restored memory behavior of Alzheimers. These findings provide conceptual implication of improvement of vascular functions as a novel therapeutic approach for the treatment of Alzheimers disease.
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| 10. |
- Rouhi, Pegah, et al.
(författare)
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Hypoxia-induced metastasis model in embryonic zebrafish
- 2010
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Ingår i: Nature Protocols. - : Nature Publishing Group. - 1754-2189 .- 1750-2799. ; 5:12, s. 1911-1918
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Tidskriftsartikel (refereegranskat)abstract
- Hypoxia facilitates tumor invasion and metastasis by promoting neovascularization and co-option of tumor cells in the peritumoral vasculature, leading to dissemination of tumor cells into the circulation. However, until recently, animal models and imaging technology did not enable monitoring of the early events of tumor cell invasion and dissemination in living animals. We recently developed a zebrafish metastasis model to dissect the detailed 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 are implanted into the perivitelline cavity of 48-h-old zebrafish embryos, which are subsequently placed in hypoxic water for 3 d. Tumor cell invasion, metastasis and pathological angiogenesis are detected under fluorescent microscopy in the living fish. The average experimental time for this model is 7 d. Our protocol offers a remarkable opportunity to study molecular mechanisms of hypoxia-induced cancer metastasis.
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