| 1. |
- Korhonen, Emilia A., et al.
(author)
-
Lymphangiogenesis requires Ang2/Tie/PI3K signaling for VEGFR3 cell-surface expression
- 2022
-
In: Journal of Clinical Investigation. - : American Society for Clinical Investigation. - 0021-9738 .- 1558-8238. ; 132:15
-
Journal article (peer-reviewed)abstract
- Vascular endothelial growth factor C (VEGF-C) induces lymphangiogenesis via VEGF receptor 3 (VEGFR3), which is encoded by the most frequently mutated gene in human primary lymphedema. Angiopoietins (Angs) and their Tie receptors regulate lymphatic vessel development, and mutations of the ANGPT2 gene were recently found in human primary lymphedema. However, the mechanistic basis of Ang2 activity in lymphangiogenesis is not fully understood. Here, we used gene deletion, blocking Abs, transgene induction, and gene transfer to study how Ang2, its Tie2 receptor, and Tie1 regulate lymphatic vessels. We discovered that VEGF-C???induced Ang2 secretion from lymphatic endothelial cells (LECs) was involved in full Akt activation downstream of phosphoinositide 3 kinase (PI3K). Neonatal deletion of genes encoding the Tie receptors or Ang2 in LECs, or administration of an Ang2-blocking Ab decreased VEGFR3 presentation on LECs and inhibited lymphangiogenesis. A similar effect was observed in LECs upon deletion of the PI3K catalytic p110?? subunit or with small -molecule inhibition of a constitutively active PI3K located downstream of Ang2. Deletion of Tie receptors or blockade of Ang2 decreased VEGF-C???induced lymphangiogenesis also in adult mice. Our results reveal an important crosstalk between the VEGF-C and Ang signaling pathways and suggest new avenues for therapeutic manipulation of lymphangiogenesis by targeting Ang2/Tie/PI3K signaling.
|
|
| 2. |
- Vaahtomeri, Kari, et al.
(author)
-
Lymphangiogenesis guidance by paracrine and pericellular factors
- 2017
-
In: Genes & Development. - : Cold Spring Harbor Laboratory. - 0890-9369 .- 1549-5477. ; 31:16, s. 1615-1634
-
Research review (peer-reviewed)abstract
- Lymphatic vessels are important for tissue fluid homeostasis, lipid absorption, and immune cell trafficking and are involved in the pathogenesis of several human diseases. The mechanisms by which the lymphatic vasculature network is formed, remodeled, and adapted to physiological and pathological challenges are controlled by an intricate balance of growth factor and biomechanical cues. These transduce signals for the readjustment of gene expression and lymphatic endothelial migration, proliferation, and differentiation. In this review, we describe several of these cues and how they are integrated for the generation of functional lymphatic vessel networks.
|
|
| 3. |
- Aspelund, Aleksanteri, et al.
(author)
-
Lymphatic System in Cardiovascular Medicine
- 2016
-
In: Circulation Research. - 0009-7330 .- 1524-4571. ; 118:3, s. 515-530
-
Research review (peer-reviewed)abstract
- The mammalian circulatory system comprises both the cardiovascular system and the lymphatic system. In contrast to the blood vascular circulation, the lymphatic system forms a unidirectional transit pathway from the extracellular space to the venous system. It actively regulates tissue fluid homeostasis, absorption of gastrointestinal lipids, and trafficking of antigen-presenting cells and lymphocytes to lymphoid organs and on to the systemic circulation. The cardinal manifestation of lymphatic malfunction is lymphedema. Recent research has implicated the lymphatic system in the pathogenesis of cardiovascular diseases including obesity and metabolic disease, dyslipidemia, inflammation, atherosclerosis, hypertension, and myocardial infarction. Here, we review the most recent advances in the field of lymphatic vascular biology, with a focus on cardiovascular disease.
|
|
| 4. |
- Aspelund, Aleksanteri, et al.
(author)
-
The Schlemm's canal is a VEGF-C/VEGFR-3-responsive lymphatic-like vessel
- 2014
-
In: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 124:9, s. 3975-3986
-
Journal article (peer-reviewed)abstract
- In glaucoma, aqueous outflow into the Schlemm's canal (SC) is obstructed. Despite striking structural and functional similarities with the lymphatic vascular, system, it is unknown whether the SC is a blood or lymphatic vessel. Here, we demonstrated the expression of lymphatic endothelial cell markers by the SC in murine and zebrafish models as well as in human eye tissue. The initial stages of SC development involved induction of the transcription factor PROX1 and the lymphangiogenic receptor tyrosine kinase VEGFR-3 in venous endothelial cells in postnatal mice. Using gene deletion and function-blocking antibodies in mice, we determined that the lymphangiogenic growth factor VEGF-C and its receptor, VEGFR-3, are essential for SC development. Delivery of VEGF-C into the adult eye resulted in sprouting, proliferation, and growth of SC endothelial cells, whereas VEGF-A obliterated the aqueous outflow system. Furthermore, a single injection of recombinant VEGF-C induced SC growth and was associated with trend toward a sustained decrease in intraocular pressure in adult mice. These results reveal the evolutionary conservation of the lymphatic-like phenotype of the SC, implicate VEGF-C and VEGFR-3 as critical regulators of SC lymphangiogenesis, and provide a basis for further studies on therapeutic manipulation of the SC with VEGF-C in glaucoma treatment.
|
|
| 5. |
|
|
| 6. |
- Baluk, Peter, et al.
(author)
-
Transgenic Overexpression of Interleukin-1β Induces Persistent Lymphangiogenesis But Not Angiogenesis in Mouse Airways.
- 2013
-
In: The American journal of pathology. - : Elsevier BV. - 1525-2191 .- 0002-9440. ; 182:4, s. 1434-1447
-
Journal article (peer-reviewed)abstract
- These studies used bi-transgenic Clara cell secretory protein (CCSP)/IL-1β mice that conditionally overexpress IL-1β in Clara cells to determine whether IL-1β can promote angiogenesis and lymphangiogenesis in airways. Doxycycline treatment induced rapid, abundant, and reversible IL-1β production, influx of neutrophils and macrophages, and conspicuous and persistent lymphangiogenesis, but surprisingly no angiogenesis. Gene profiling showed many up-regulated genes, including chemokines (Cxcl1, Ccl7), cytokines (tumor necrosis factor α, IL-1β, and lymphotoxin-β), and leukocyte genes (S100A9, Aif1/Iba1). Newly formed lymphatics persisted after IL-1β overexpression was stopped. Further studies examined how IL1R1 receptor activation by IL-1β induced lymphangiogenesis. Inactivation of vascular endothelial growth factor (VEGF)-C and VEGF-D by adeno-associated viral vector-mediated soluble VEGFR-3 (VEGF-C/D Trap) completely blocked lymphangiogenesis, showing its dependence on VEGFR-3 ligands. Consistent with this mechanism, VEGF-C immunoreactivity was present in some Aif1/Iba-immunoreactive macrophages. Because neutrophils contribute to IL-1β-induced lung remodeling in newborn mice, we examined their potential role in lymphangiogenesis. Triple-transgenic CCSP/IL-1β/CXCR2(-/-) mice had the usual IL-1β-mediated lymphangiogenesis but no neutrophil recruitment, suggesting that neutrophils are not essential. IL1R1 immunoreactivity was found on some epithelial basal cells and neuroendocrine cells, suggesting that these cells are targets of IL-1β, but was not detected on lymphatics, blood vessels, or leukocytes. We conclude that lymphangiogenesis triggered by IL-1β overexpression in mouse airways is driven by VEGF-C/D from macrophages but notneutrophils recruited by chemokines from epithelial cells that express IL1R1.
|
|
| 7. |
- Bergsten, Erika, et al.
(author)
-
PDGF-D is a specific, protease-activated ligand for the PDGF beta-receptor
- 2001
-
In: Nature Cell Biology. - : Macmillan Magazines Ltd. - 1465-7392 .- 1476-4679. ; 3:5, s. 512-516
-
Journal article (peer-reviewed)abstract
- The term 'platelet-derived growth factor' (PDGF) refers to a family of disulphide-bonded dimeric isoforms that are important for growth, survival and function in several types of connective tissue cell. So far, three different PDGF chains have been identified - the classical PDGF-A and PDGF-B and the recently identified PDGF-C. PDGF isoforms (PDGF-AA, AB, BB and CC) exert their cellular effects by differential binding to two receptor tyrosine kinases. The PDGF alpha-receptor (PDGFR-alpha) binds to all three PDGF chains, whereas the beta-receptor (PDGFR-beta) binds only to PDGF-B. Gene-targeting studies using mice have shown that the genes for PDGF-A and PDGF-B, as well as the two PDGFR genes, are essential for normal development. Furthermore, overexpression of PDGFs is linked to different pathological conditions, including malignancies, atherosclerosis and fibroproliferative diseases. Here we have identify and characterize a fourth member of the PDGF family, PDGF-D. PDGF-D has a two-domain structure similar to PDGF-C and is secreted as a disulphide-linked homodimer, PDGF-DD. Upon limited proteolysis, PDGF-DD is activated and becomes a specific agonistic ligand for PDGFR-beta. PDGF-DD is the first known PDGFR-beta-specific ligand, and its unique receptor specificity indicates that it may be important for development and pathophysiology in several organs.
|
|
| 8. |
- Calvo, Charles-Félix, et al.
(author)
-
Vascular endothelial growth factor receptor 3 directly regulates murine neurogenesis.
- 2011
-
In: Genes & Development. - : Cold Spring Harbor Laboratory. - 0890-9369 .- 1549-5477. ; 25:8
-
Journal article (peer-reviewed)abstract
- Neural stem cells (NSCs) are slowly dividing astrocytes that are intimately associated with capillary endothelial cells in the subventricular zone (SVZ) of the brain. Functionally, members of the vascular endothelial growth factor (VEGF) family can stimulate neurogenesis as well as angiogenesis, but it has been unclear whether they act directly via VEGF receptors (VEGFRs) expressed by neural cells, or indirectly via the release of growth factors from angiogenic capillaries. Here, we show that VEGFR-3, a receptor required for lymphangiogenesis, is expressed by NSCs and is directly required for neurogenesis. Vegfr3:YFP reporter mice show VEGFR-3 expression in multipotent NSCs, which are capable of self-renewal and are activated by the VEGFR-3 ligand VEGF-C in vitro. Overexpression of VEGF-C stimulates VEGFR-3-expressing NSCs and neurogenesis in the SVZ without affecting angiogenesis. Conversely, conditional deletion of Vegfr3 in neural cells, inducible deletion in subventricular astrocytes, and blocking of VEGFR-3 signaling with antibodies reduce SVZ neurogenesis. Therefore, VEGF-C/VEGFR-3 signaling acts directly on NSCs and regulates adult neurogenesis, opening potential approaches for treatment of neurodegenerative diseases.
|
|
| 9. |
- Dixelius, Johan, et al.
(author)
-
Ligand-induced vascular endothelial growth factor receptor-3 (VEGFR-3) heterodimerization with VEGFR-2 in primary lymphatic endothelial cells regulates tyrosine phosphorylation sites
- 2003
-
In: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 278, s. 40973-
-
Journal article (peer-reviewed)abstract
- Vascular endothelial growth factors (VEGFs) regulate the development and growth of the blood and lymphatic vascular systems. Of the three VEGF receptors (VEGFR), VEGFR-1 and -2 are expressed on blood vessels; VEGFR-2 is found also on lymphatic vessels. VEGFR-3 is expressed mainly on lymphatic vessels but it is also up-regulated in tumor angiogenesis. Although VEGFR-3 is essential for proper lymphatic development, its signal transduction mechanisms are still incompletely understood. Trans-phosphorylation of activated, dimerized receptor tyrosine kinases is known to be critical for the regulation of kinase activity and for receptor interaction with signal transduction molecules. In this study, we have identified five tyrosyl phosphorylation sites in the VEGFR-3 carboxyl-terminal tail. These sites were used both in VEGFR-3 overexpressed in 293 cells and when the endogenous VEGFR-3 was activated in lymphatic endothelial cells. Interestingly, VEGF-C stimulation of lymphatic endothelial cells also induced the formation of VEGFR-3/VEGFR-2 heterodimers, in which VEGFR-3 was phosphorylated only at three of the five sites while the two most carboxyl-terminal tyrosine residues appeared not to be accessible for the VEGFR-2 kinase. Our data suggest that the carboxyl-terminal tail of VEGFR-3 provides important regulatory tyrosine phosphorylation sites with potential signal transduction capacity and that these sites are differentially used in ligand-induced homo- and heterodimeric receptor complexes.
|
|
| 10. |
- Eichmann, Anne, et al.
(author)
-
Neural guidance molecules regulate vascular remodeling and vessel navigation.
- 2005
-
In: Genes & Development. - : Cold Spring Harbor Laboratory. - 0890-9369 .- 1549-5477. ; 19:9
-
Journal article (peer-reviewed)abstract
- The development of the embryonic blood vascular and lymphatic systems requires the coordinated action of several transcription factors and growth factors that target endothelial and periendothelial cells. However, according to recent studies, the precise "wiring" of the vascular system does not occur without an ordered series of guidance decisions involving several molecules initially discovered for axons in the nervous system, including ephrins, netrins, slits, and semaphorins. Here, we summarize the new advances in our understanding of the roles of these axonal pathfinding molecules in vascular remodeling and vessel guidance, indicating that neuronal axons and vessel sprouts use common molecular mechanisms for navigation in the body.
|
|
