scholarly journals VEGFR3 does not sustain retinal angiogenesis without VEGFR2

2015 ◽  
Vol 112 (3) ◽  
pp. 761-766 ◽  
Author(s):  
Georgia Zarkada ◽  
Krista Heinolainen ◽  
Taija Makinen ◽  
Yoshiaki Kubota ◽  
Kari Alitalo
Keyword(s):  
Blood Vessels ◽  
Vascular System ◽  
Notch Pathway ◽  
Lymphatic Vessels ◽  
Signal Transduction Pathway ◽  
Retinal Angiogenesis ◽  
Vegfr2 Signaling ◽  
Endothelial Growth Factors ◽  
Tip Cells

Angiogenesis, the formation of new blood vessels, is regulated by vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs). VEGFR2 is abundant in the tip cells of angiogenic sprouts, where VEGF/VEGFR2 functions upstream of the delta-like ligand 4 (DLL4)/Notch signal transduction pathway. VEGFR3 is expressed in all endothelia and is indispensable for angiogenesis during early embryonic development. In adults, VEGFR3 is expressed in angiogenic blood vessels and some fenestrated endothelia. VEGFR3 is abundant in endothelial tip cells, where it activates Notch signaling, facilitating the conversion of tip cells to stalk cells during the stabilization of vascular branches. Subsequently, Notch activation suppresses VEGFR3 expression in a negative feedback loop. Here we used conditional deletions and a Notch pathway inhibitor to investigate the cross-talk between VEGFR2, VEGFR3, and Notch in vivo. We show that postnatal angiogenesis requires VEGFR2 signaling also in the absence of Notch or VEGFR3, and that even small amounts of VEGFR2 are able to sustain angiogenesis to some extent. We found that VEGFR2 is required independently of VEGFR3 for endothelial DLL4 up-regulation and angiogenic sprouting, and for VEGFR3 functions in angiogenesis. In contrast, VEGFR2 deletion had no effect, whereas VEGFR3 was essential for postnatal lymphangiogenesis, and even for lymphatic vessel maintenance in adult skin. Knowledge of these interactions and the signaling functions of VEGFRs in blood vessels and lymphatic vessels is essential for the therapeutic manipulation of the vascular system, especially when considering multitargeted antiangiogenic treatments.

Recombinant TAT-Thymosin β-4 Promotes Angiogenesis by Activating VEGFR2 Signaling Pathway

2021 ◽  
Author(s):  
Chul Min Kim ◽  
Yun-Mi Jeong ◽  
Jae-Hun Kim ◽  
Guolong Jin ◽  
Hyeongkwon Oh ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Signaling Pathway ◽  
Dynamic Equilibrium ◽  
Common Type ◽  
Cell Penetrating Peptide ◽  
Angiogenic Potential ◽  
Angiogenic Effect ◽  
Vegfr2 Signaling

Abstract Thymosin β-4 is a 43-amino acid intracellular polypeptide that was originally isolated from bovine thymus. Of the 16 known thymosin families, thymosin β-4 is the most common type found in all tissues. Thymosin β-4 regulates angiogenesis, cell differentiation, morphogenesis, migration, and organogenesis and is linked to a dynamic equilibrium between G-actin and F-actin. In particular, thymosin β-4 is well-known for its angiogenic and anti-apoptotic functions. In this study, we synthesized thymosin β-4 linked with the well-known cell-penetrating peptide TAT (YGRKKRRRQRRR). TAT-thymosin β-4 promotes angiogenesis and cell migration in vitro via the VEGFR2 signaling pathway and reduces apoptosis. To examine angiogenic potential in vivo, a Matrigel Plus assay was conducted that revealed the angiogenic effect of TAT-thymosin β-4. In conclusion, TAT-thymosin β-4 promotes blood vessels and is expected to be applicable in regenerative medicine for all organs requiring blood vessels.

Vascular zip codes in angiogenesis and metastasis

2004 ◽  
Vol 32 (3) ◽  
pp. 397-402 ◽  
Author(s):  
E. Ruoslahti
Keyword(s):  
Blood Vessels ◽  
Lymphatic Vessels ◽  
Therapeutic Agents ◽  
In Vivo Screening ◽  
Normal Tissues ◽  
Tumour Metastasis ◽  
Selective Expression ◽  
Vascular Markers ◽  
Tumour Blood

In vivo screening of phage-displayed peptide libraries has revealed extensive molecular differences in the blood vessels of individual normal tissues. Pathological lesions also put their signature on the vasculature; in tumours, both blood and lymphatic vessels differ from normal vessels. The changes that characterize tumour blood vessels include selective expression of certain integrins. Peptides isolated by in vivo phage display for homing to tumours have been shown to be useful in directing therapeutic agents to experimental tumours. The targeting can enhance the efficacy of the therapy while reducing side effects. Phage screening has also revealed lung-specific vascular markers that promote tumour metastasis to the lungs by mediating specific adherence of tumour cells to the lung vasculature. These phage-screening studies have revealed a previously unsuspected degree of vascular specialization and provide potentially useful guidance devices for targeted therapies.

scholarly journals Investigating lymphangiogenesis in vitro and in vivo using engineered human lymphatic vessel networks

2021 ◽  
Vol 118 (31) ◽  
pp. e2101931118
Author(s):  
Shira Landau ◽  
Abigail Newman ◽  
Shlomit Edri ◽  
Inbal Michael ◽  
Shahar Ben-Shaul ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Vessel ◽  
Blood Vessels ◽  
Lymphatic Vessel ◽  
Lymphatic Vessels ◽  
Lymphatic Endothelial Cells ◽  
Supporting Cells ◽  
Vessel Formation ◽  
Vessel Networks

The lymphatic system is involved in various biological processes, including fluid transport from the interstitium into the venous circulation, lipid absorption, and immune cell trafficking. Despite its critical role in homeostasis, lymphangiogenesis (lymphatic vessel formation) is less widely studied than its counterpart, angiogenesis (blood vessel formation). Although the incorporation of lymphatic vasculature in engineered tissues or organoids would enable more precise mimicry of native tissue, few studies have focused on creating engineered tissues containing lymphatic vessels. Here, we populated thick collagen sheets with human lymphatic endothelial cells, combined with supporting cells and blood endothelial cells, and examined lymphangiogenesis within the resulting constructs. Our model required just a few days to develop a functional lymphatic vessel network, in contrast to other reported models requiring several weeks. Coculture of lymphatic endothelial cells with the appropriate supporting cells and intact PDGFR-β signaling proved essential for the lymphangiogenesis process. Additionally, subjecting the constructs to cyclic stretch enabled the creation of complex muscle tissue aligned with the lymphatic and blood vessel networks, more precisely biomimicking native tissue. Interestingly, the response of developing lymphatic vessels to tensile forces was different from that of blood vessels; while blood vessels oriented perpendicularly to the stretch direction, lymphatic vessels mostly oriented in parallel to the stretch direction. Implantation of the engineered lymphatic constructs into a mouse abdominal wall muscle resulted in anastomosis between host and implant lymphatic vasculatures, demonstrating the engineered construct's potential functionality in vivo. Overall, this model provides a potential platform for investigating lymphangiogenesis and lymphatic disease mechanisms.

Heterogeneity of Endothelial Sheet Migration: Role in Angiogenic Plasticity.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3692-3692
Author(s):  
Solomon F. Ofori-Acquah ◽  
Troy Stevens
Keyword(s):  
Endothelial Cells ◽  
Blood Vessels ◽  
Vascular System ◽  
Phenotypic Traits ◽  
Collective Cell Migration ◽  
Isolated Cells ◽  
Wound Edge ◽  
Total Distance ◽  
Sheet Migration

Abstract The vascular system is a complex network of conduit and microvascular vessels exposed to different microenvironments that imprints unique phenotypic traits on individual endothelial cell populations. Endothelial cells in fully differentiated blood vessels in adult tissues have a quiescent phenotype characterized by an increased resistance to proliferate, migrate or undergo apoptosis. The intrinsic capacity of endothelial cells to switch from a quiescent to angiogenic phenotype however plays an important role in wound healing, several vascular proliferative disorders and tumor angiogenesis. Endothelial cells revert to an angiogenic phenotype as isolated cells in culture nonetheless they are contact inhibited at confluence reflecting their in vivo phenotype in the endothelium. In this study, we used time-lapse video microscopy to study early events in endothelial sheet migration in confluent monolayers of primary endothelial cells derived from conduit (PAECs) and microvascular (PMVECs) blood vessels. Recordings were made in a live cell chamber and were restricted to six hours to minimize the effect of proliferation on sheet migration. PMVECs at the wound edge were significantly highly spread and squamous in appearance compared to PAECs, which had a distinctly more cuboidal morphology. Majority (>95%) of PMVECs at the wound edge produced extensive lamellipodia based on morphology and dynamics that measured 25 μm ± 4 μm. By contrast, PAECs formed significantly smaller lamelipodia which extended by 8 μm ± 4 μm. On average PMVEC sheets migrated at a speed of 12.5 μm per hour covering a total distance of 75 μm ± 15 μm (n=6). Sheet migration rate in PMVECs was 3-fold faster than in PAECs (3.8 μm per hour), which covered a total distance of 23 μm ± 10 μm in the same time period. To unravel the molecular basis for this functional diversity, gene micro array analysis was performed. We identified unique transcriptional profiles for cell-cell adhesion molecules, integrins and disintegrin-metalloproteases each with a distinct role in collective cell migration. In particular, integrin alpha 7, which is a major regulator of lamellipodia formation was found to be 20-fold more abundant in PMVECs than in PAECs. This study provides molecular and functional evidence for heterogeneity of endothelial sheet migration. This central finding highlights variability in angiogenic plasticity in fully differentiated endothelial cells, which may have important ramifications for anti-angiogenesis therapy.

scholarly journals A novel pro-lymphangiogenic function for Th17/IL-17

Blood ◽  
2011 ◽  
Vol 118 (17) ◽  
pp. 4630-4634 ◽  
Author(s):  
Sunil K. Chauhan ◽  
Yiping Jin ◽  
Sunali Goyal ◽  
Hyun Soo Lee ◽  
Thomas A. Fuchsluger ◽  
...  
Keyword(s):  
Cell Culture ◽  
Endothelial Cells ◽  
Autoimmune Diseases ◽  
Blood Vessels ◽  
Th17 Cells ◽  
Lymphatic Vessels ◽  
Preclinical Model ◽  
Lymphatic Endothelial Cells ◽  
Corneal Lymphangiogenesis

Abstract Th17 cells, in addition to their proinflammatory functions, have been recognized as potent inducers of angiogenesis in autoimmune diseases and malignancies. In the present study, we demonstrate distinct mechanisms by which IL-17 induces lymphangiogenesis. Using the mouse cornea micropocket and cell culture assays, our data demonstrate that IL-17 directly promotes growth of lymphatic vessels by inducing increased expression of prolymphangiogenic VEGF-D and proliferation of lymphatic endothelial cells. However, IL-17–induced growth of blood vessels is primarily mediated through IL-1β secretion by IL-17–responsive cells. Furthermore, in vivo blockade of IL-17 in a preclinical model of Th17-dominant autoimmune ocular disease demonstrates a significant reduction in the corneal lymphangiogenesis and in the progression of clinical disease. Taken together, our findings demonstrate a novel prolymphangiogenic function for Th17/IL-17, indicating that IL-17 can promote the progression and amplification of immunity in part through its induction of lymphangiogenesis.

Microfluidics of blood in blood vessels stenosis

2016 ◽  
Vol 11 (2) ◽  
pp. 210-217 ◽  
Author(s):  
A.T. Akhmetov ◽  
A.A. Valiev ◽  
A.A. Rakhimov ◽  
S.P. Sametov ◽  
R.R. Habibullina
Keyword(s):  
Blood Flow ◽  
Blood Vessels ◽  
Hydraulic Resistance ◽  
Microfluidic Device ◽  
Human Body ◽  
Vascular System ◽  
Hydrodynamic Conditions ◽  
Microstructure Change ◽  
Healthy Part

It is mentioned in the paper that hydrodynamic conditions of a flow in blood vessels with the stenosis are abnormal in relation to the total hemodynamic conditions of blood flow in a vascular system of a human body. A microfluidic device developed with a stepped narrowing for studying of the blood flow at abnormal conditions allowed to reveal blood structure in microchannels simulating the stenosis. Microstructure change is observed during the flow of both native and diluted blood through the narrowing. The study of hemorheological properties allowed us to determine an increasing contribution of the hydraulic resistance of the healthy part of the vessel during the stenosis formation.

In Vivo Spin Trapping of Glyceryl Trinitrate–Derived Nitric Oxide in Rabbit Blood Vessels and Organs

Circulation ◽  
1995 ◽  
Vol 92 (7) ◽  
pp. 1876-1882 ◽  
Author(s):  
Alexander Mülsch ◽  
Peter Mordvintcev ◽  
Eberhard Bassenge ◽  
Frank Jung ◽  
Bernd Clement ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Glyceryl Trinitrate ◽  
Blood Vessels ◽  
Spin Trapping ◽  
Rabbit Blood

A High-Affinity Human Antibody That Targets Tumoral Blood Vessels

Blood ◽  
1999 ◽  
Vol 94 (1) ◽  
pp. 192-198 ◽  
Author(s):  
Lorenzo Tarli ◽  
Enrica Balza ◽  
Francesca Viti ◽  
Laura Borsi ◽  
Patrizia Castellani ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Small Cell Lung Carcinoma ◽  
Antibody Fragment ◽  
Human Colon ◽  
Experimental Models ◽  
Human Antibody ◽  
Cell Lung Carcinoma ◽  
High Affinity ◽  
Biodistribution Studies

Angiogenesis is a characteristic feature of many aggressive tumors and of other relevant disorders. Molecules capable of specifically binding to new-forming blood vessels, but not to mature vessels, could be used as selective vehicles and would, therefore, open diagnostic and therapeutic opportunities. We have studied the distribution of the ED-B oncofetal domain of fibronectin, a marker of angiogenesis, in four different tumor animal models: the F9 murine teratocarcinoma, SKMEL-28 human melanoma, N592 human small cell lung carcinoma, and C51 human colon carcinoma. In all of these experimental models we observed accumulation of the fibronectin isoform containing the ED-B domain around neovascular structures when the tumors were in the exponentially growing phase, but not in the slow-growing phase. Then we performed biodistribution studies in mice bearing a subcutaneously implanted F9 murine teratocarcinoma, using a high-affinity human antibody fragment (L19) directed against the ED-B domain of fibronectin. Radiolabeled L19, but not an irrelevant anti-lysozyme antibody fragment (D1.3), efficiently localizes in the tumoral vessels. The maximal dose of L19 accumulated in the tumor was observed 3 hours after injection (8.2% injected dose per gram). By virtue of the rapid clearance of the antibody fragment from the circulation, tumor-to-blood ratios of 1.9, 3.7, and 11.8 were obtained at 3, 5, and 24 hours, respectively. The tumor-targeting performance of L19 was not dose-dependent in the 0.7 to 10 μg range of injected antibody. The integral of the radioactivity localized in tumoral vessels over 24 hours was greater than 70-fold higher than the integral of the radioactivity in blood over the same time period, normalized per gram of tissue or fluid. These findings quantitatively show that new-forming blood vessels can selectively be targeted in vivo using specific antibodies, and suggest that L19 may be of clinical utility for the immunoscintigraphic detection of angiogenesis in patients.

scholarly journals Oxidized LDLs as Signaling Molecules

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1184
Author(s):  
Jean-Marc Zingg ◽  
Adelina Vlad ◽  
Roberta Ricciarelli
Keyword(s):  
Free Radicals ◽  
Cellular Response ◽  
Vascular System ◽  
Signaling Molecules ◽  
Scavenger Receptors ◽  
Physiological Relevance ◽  
Reactive Radicals ◽  
Accumulation Of Lipids

Levels of oxidized low-density lipoproteins (oxLDLs) are usually low in vivo but can increase whenever the balance between formation and scavenging of free radicals is impaired. Under normal conditions, uptake and degradation represent the physiological cellular response to oxLDL exposure. The uptake of oxLDLs is mediated by cell surface scavenger receptors that may also act as signaling molecules. Under conditions of atherosclerosis, monocytes/macrophages and vascular smooth muscle cells highly exposed to oxLDLs tend to convert to foam cells due to the intracellular accumulation of lipids. Moreover, the atherogenic process is accelerated by the increased expression of the scavenger receptors CD36, SR-BI, LOX-1, and SRA in response to high levels of oxLDL and oxidized lipids. In some respects, the effects of oxLDLs, involving cell proliferation, inflammation, apoptosis, adhesion, migration, senescence, and gene expression, can be seen as an adaptive response to the rise of free radicals in the vascular system. Unlike highly reactive radicals, circulating oxLDLs may signal to cells at more distant sites and possibly trigger a systemic antioxidant defense, thus elevating the role of oxLDLs to that of signaling molecules with physiological relevance.

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