scholarly journals Regulation of monocyte cell fate by blood vessels mediated by Notch signalling

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Jaba Gamrekelashvili ◽  
Roberto Giagnorio ◽  
Jasmin Jussofie ◽  
Oliver Soehnlein ◽  
Johan Duchene ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Vessels ◽  
Cell Fate ◽  
Myeloid Cell ◽  
Notch Signalling ◽  
Monocyte Cell ◽  
Genetic Deletion ◽  
Cell Fate Tracking

Abstract A population of monocytes, known as Ly6Clo monocytes, patrol blood vessels by crawling along the vascular endothelium. Here we show that endothelial cells control their origin through Notch signalling. Using combinations of conditional genetic deletion strategies and cell-fate tracking experiments we show that Notch2 regulates conversion of Ly6Chi monocytes into Ly6Clo monocytes in vivo and in vitro, thereby regulating monocyte cell fate under steady-state conditions. This process is controlled by Notch ligand delta-like 1 (Dll1) expressed by a population of endothelial cells that constitute distinct vascular niches in the bone marrow and spleen in vivo, while culture on recombinant DLL1 induces monocyte conversion in vitro. Thus, blood vessels regulate monocyte conversion, a form of committed myeloid cell fate regulation.

scholarly journals Activated Notch4 Inhibits Angiogenesis: Role of β1-Integrin Activation

2002 ◽  
Vol 22 (8) ◽  
pp. 2830-2841 ◽  
Author(s):  
Kevin G. Leong ◽  
Xiaolong Hu ◽  
Linheng Li ◽  
Michela Noseda ◽  
Bruno Larrivée ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Fate ◽  
Chorioallantoic Membrane ◽  
Surface Expression ◽  
Cell Phenotype ◽  
Β1 Integrin ◽  
Cell Fate Decisions ◽  
Β1 Integrins

ABSTRACT Notch4 is a member of the Notch family of transmembrane receptors that is expressed primarily on endothelial cells. Activation of Notch in various cell systems has been shown to regulate cell fate decisions. The sprouting of endothelial cells from microvessels, or angiogenesis, involves the modulation of the endothelial cell phenotype. Based on the function of other Notch family members and the expression pattern of Notch4, we postulated that Notch4 activation would modulate angiogenesis. Using an in vitro endothelial-sprouting assay, we show that expression of constitutively active Notch4 in human dermal microvascular endothelial cells (HMEC-1) inhibits endothelial sprouting. We also show that activated Notch4 inhibits vascular endothelial growth factor (VEGF)-induced angiogenesis in the chick chorioallantoic membrane in vivo. Activated Notch4 does not inhibit HMEC-1 proliferation or migration through fibrinogen. However, migration through collagen is inhibited. Our data show that Notch4 cells exhibit increased β1-integrin-mediated adhesion to collagen. HMEC-1 expressing activated Notch4 do not have increased surface expression of β1-integrins. Rather, we demonstrate that Notch4-expressing cells display β1-integrin in an active, high-affinity conformation. Furthermore, using function-activating β1-integrin antibodies, we demonstrate that activation of β1-integrins is sufficient to inhibit VEGF-induced endothelial sprouting in vitro and angiogenesis in vivo. Our findings suggest that constitutive Notch4 activation in endothelial cells inhibits angiogenesis in part by promoting β1-integrin-mediated adhesion to the underlying matrix.

scholarly journals Preclinical Testing of Living Tissue-Engineered Heart Valves for Pediatric Patients, Challenges and Opportunities

2021 ◽  
Vol 8 ◽  
Author(s):  
Ionela Movileanu ◽  
Marius Harpa ◽  
Hussam Al Hussein ◽  
Lucian Harceaga ◽  
Alexandru Chertes ◽  
...  
Keyword(s):  
Stem Cells ◽  
Endothelial Cells ◽  
Cell Fate ◽  
Heart Valve ◽  
Pediatric Patients ◽  
Living Tissue ◽  
Congenital Diseases ◽  
Challenges And Opportunities

Introduction: Pediatric patients with cardiac congenital diseases require heart valve implants that can grow with their natural somatic increase in size. Current artificial valves perform poorly in children and cannot grow; thus, living-tissue-engineered valves capable of sustaining matrix homeostasis could overcome the current drawbacks of artificial prostheses and minimize the need for repeat surgeries.Materials and Methods: To prepare living-tissue-engineered valves, we produced completely acellular ovine pulmonary valves by perfusion. We then collected autologous adipose tissue, isolated stem cells, and differentiated them into fibroblasts and separately into endothelial cells. We seeded the fibroblasts in the cusp interstitium and onto the root adventitia and the endothelial cells inside the lumen, conditioned the living valves in dedicated pulmonary heart valve bioreactors, and pursued orthotopic implantation of autologous cell-seeded valves with 6 months follow-up. Unseeded valves served as controls.Results: Perfusion decellularization yielded acellular pulmonary valves that were stable, no degradable in vivo, cell friendly and biocompatible, had excellent hemodynamics, were not immunogenic or inflammatory, non thrombogenic, did not calcify in juvenile sheep, and served as substrates for cell repopulation. Autologous adipose-derived stem cells were easy to isolate and differentiate into fibroblasts and endothelial-like cells. Cell-seeded valves exhibited preserved viability after progressive bioreactor conditioning and functioned well in vivo for 6 months. At explantation, the implants and anastomoses were intact, and the valve root was well integrated into host tissues; valve leaflets were unchanged in size, non fibrotic, supple, and functional. Numerous cells positive for a-smooth muscle cell actin were found mostly in the sinus, base, and the fibrosa of the leaflets, and most surfaces were covered by endothelial cells, indicating a strong potential for repopulation of the scaffold.Conclusions: Tissue-engineered living valves can be generated in vitro using the approach described here. The technology is not trivial and can provide numerous challenges and opportunities, which are discussed in detail in this paper. Overall, we concluded that cell seeding did not negatively affect tissue-engineered heart valve (TEHV) performance as they exhibited as good hemodynamic performance as acellular valves in this model. Further understanding of cell fate after implantation and the timeline of repopulation of acellular scaffolds will help us evaluate the translational potential of this technology.

scholarly journals Development and Application of Endothelial Cells Derived From Pluripotent Stem Cells in Microphysiological Systems Models

2021 ◽  
Vol 8 ◽  
Author(s):  
Crystal C. Kennedy ◽  
Erin E. Brown ◽  
Nadia O. Abutaleb ◽  
George A. Truskey
Keyword(s):  
Stem Cells ◽  
Endothelial Cells ◽  
Blood Vessels ◽  
Pluripotent Stem Cells ◽  
The Body ◽  
Organ Systems ◽  
Temporal Waveform ◽  
Induced Pluripotent

The vascular endothelium is present in all organs and blood vessels, facilitates the exchange of nutrients and waste throughout different organ systems in the body, and sets the tone for healthy vessel function. Mechanosensitive in nature, the endothelium responds to the magnitude and temporal waveform of shear stress in the vessels. Endothelial dysfunction can lead to atherosclerosis and other diseases. Modeling endothelial function and dysfunction in organ systems in vitro, such as the blood–brain barrier and tissue-engineered blood vessels, requires sourcing endothelial cells (ECs) for these biomedical engineering applications. It can be difficult to source primary, easily renewable ECs that possess the function or dysfunction in question. In contrast, human pluripotent stem cells (hPSCs) can be sourced from donors of interest and renewed almost indefinitely. In this review, we highlight how knowledge of vascular EC development in vivo is used to differentiate induced pluripotent stem cells (iPSC) into ECs. We then describe how iPSC-derived ECs are being used currently in in vitro models of organ function and disease and in vivo applications.

scholarly journals Adhesion of Candida albicans to Endothelial Cells under Physiological Conditions of Flow

2009 ◽  
Vol 77 (9) ◽  
pp. 3872-3878 ◽  
Author(s):  
Sarah E. W. Grubb ◽  
Craig Murdoch ◽  
Peter E. Sudbery ◽  
Stephen P. Saville ◽  
Jose L. Lopez-Ribot ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Candida Albicans ◽  
Blood Vessels ◽  
Systemic Infection ◽  
Multiple Organ ◽  
Adhesion Assay ◽  
Conflicting Evidence

ABSTRACT Candida albicans is a commensal organism that under certain circumstances can become pathogenic. During systemic infection C. albicans is disseminated via the circulation to distant organs, where it causes multiple organ failure. Despite the severity of systemic C. albicans infection, little is known about the mechanisms involved in the adhesion of this organism to the endothelium lining blood vessels. Previous studies have used static assays to examine adhesion. However, these do not realistically model blood vessels, where circulating C. albicans cells must adhere to the endothelium under conditions of flow and shear stress. Furthermore, there is conflicting evidence concerning the role played by yeast, pseudohyphal, and hyphal forms of C. albicans in adhesion to endothelium. To test the hypothesis that there may be differences in the abilities of these three morphogenic forms of C. albicans to adhere to endothelium under conditions of flow, we developed an in vitro flow adhesion assay. We found that all three forms of C. albicans rapidly bound to confluent endothelial cells under conditions of flow. Maximum adhesion was found at low shear stress levels similar to that found in postcapillary venules. Moreover, yeast forms bound in significantly greater numbers than did pseudohyphal and hyphal forms, respectively, contrasting with previous findings from static assays. These findings are consistent with recent in vivo data suggesting that yeast forms may be capable of adhering to the endothelium and migrating into the tissues before undergoing morphogenic change to cause tissue damage.

scholarly journals Erratum: Corrigendum: Regulation of monocyte cell fate by blood vessels mediated by Notch signalling

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Jaba Gamrekelashvili ◽  
Roberto Giagnorio ◽  
Jasmin Jussofie ◽  
Oliver Soehnlein ◽  
Johan Duchene ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Cell Fate ◽  
Notch Signalling ◽  
Monocyte Cell

scholarly journals Identification of Angiogenic Cargo in Extracellular Vesicles Secreted from Human Adipose Tissue-Derived Stem Cells and Induction of Angiogenesis In Vitro and In Vivo

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 495
Author(s):  
Prakash Gangadaran ◽  
Ramya Lakshmi Rajendran ◽  
Ji Min Oh ◽  
Eun Jung Oh ◽  
Chae Moon Hong ◽  
...  
Keyword(s):  
Stem Cells ◽  
Endothelial Cells ◽  
Adipose Tissue ◽  
Blood Vessels ◽  
Extracellular Vesicles ◽  
Human Adipose Tissue ◽  
Antibody Array ◽  
Angiogenic Proteins

Angiogenesis is defined as the generation of new blood vessels or the sprouting of endothelial cells from a pre-existing vascular network. Angiogenesis occurs during the growth and development of an organism, the response of organs or tissues to injury, and during cancer development and progression. The majority of studies on stem-cell-derived extracellular vesicles (EVs) have used cell lines, and have primarily focused on well-known solitary proteins. Here, we isolated stem cells from human adipose tissue (ADSCs), and we isolated EVs from them (ADSC-EVs). The ADSC-EVs were characterised and 20 angiogenic proteins were analysed using an angiogenic antibody array. Furthermore, we analysed the ability of ADSC-EVs to induce angiogenesis in vitro and in vivo. ADSC-EVs were positive for CD81 and negative for GM130, calnexin, and cytochrome-C. ADSC-EVs showed typical EV spherical morphology and were ~200 nm in size. ADSC-EVs were found to contain angiogenic proteins as cargo, among which interleukin 8 (IL-8) was the most abundant, followed by chemokine (C-C motif) ligand 2 (CCL2), a tissue inhibitor of metalloproteinases 1 (TIMP-1), TIMP-2, and vascular endothelial growth factor-D (VEGF-D). ADSC-EVs treatment increased the proliferation, migration, total vessel length, total number of junctions, and junction density of endothelial cells in vitro. The results of an in vivo Matrigel plug assay revealed that ADSC-EVs induced more blood vessels in the Matrigel compared with the control. These results demonstrate that ADSC-EVs contain angiogenic proteins as cargo and promote angiogenesis in vitro and in vivo. Therefore, ADSC-EVs have potential for therapeutic use in ischaemia.

Novel Synthetic Peptide Promotes Vascular Angiogenesis In Vitro and In Vivo in a VEGF-Independent Pathway.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3913-3913
Author(s):  
Britta Hardy ◽  
Annat Raiter ◽  
Chana Weiss ◽  
Alexander Battler
Keyword(s):  
Endothelial Cells ◽  
Blood Vessels ◽  
Synthetic Peptide ◽  
Fold Increase ◽  
In Vitro Assays ◽  
Similar Treatment ◽  
Mouse Ear ◽  
Post Operation

Abstract Angiogenesis is a fundamental process of generating new blood vessels by sprouting of endothelial cells from pre-existing vessels. Angiogenesis plays a crucial role in embryonic organ development and in adult vascular diseases. Adult tissues respond to hypoxia with compensatory mechanisms in which they can survive. Up-regulation of growth factors such as VEGF stimulate growth of vascular endothelial cells. Insufficient angiogenesis is relevant to many diseases such as coronary artery disease and delayed wound healing. Therapeutic angiogenesis aims to treat local hypovascularity by stimulating or inducing neovascularization for the treatment of ischemic vascular disease under the influence of an appropriate angiogenic molecule. We have identified a novel synthetic peptide, RoY, selected from a phage display peptide library by screening against endothelial cells under different physiological conditions. RoY peptide induces angiogenesis in vitro in a VEGF- independent mechanism and promotes collateral vessel growth and blood perfusion in vivo. In vitro assays demonstrated specific binding of peptide to endothelial cells and not to peripheral blood lymphocytes. Proliferation with RoY peptide at different dosages induces significant proliferation reaching 1.6 to 1.8-fold increase over control at 10ng/ml. The ability of RoY peptide to induce migration of endothelial cells was measured at different concentrations and under normoxic and hypoxic conditions using a Boyden cell migration chamber. RoY at 50 ng/ml induced a significant two-fold increase in migration compared to control and similar to VEGF. However, under hypoxia, RoY at 20 ng/ml induced a significant 2.5 fold increase in migration, significantly more migration than a similar dose under normoxia. RoY induced tube formation on Matrigel in both human umbilical vascular and dermal microvascular endothelial cells. A mouse ear angiogenesis model and a mouse ischemic hind limb model were used to evaluate the in vivo effects of RoY peptide. Angiogenesis in a mouse ear was induced by injection of RoY and was compared to the number of blood vessels in the control ear. RoY induced a 50% increase in the number of blood vessels in the treated ear. Ligation of the femoral artery in C57/ Bl mice induces ischemia in the operated leg. Injection of 1–10μg of RoY peptide to the operated ischemic legs resulted in a 100 percent perfusion in the operated leg versus the control non-operated leg. This increase was maintained and significant 21 days post operation while similar treatment with VEGF was maximal 14 days post operation and at 21 days the percent perfusion decreased. A possible angiogenic mechanisms of the synthetic novel peptide will be discussed. However, we have found that endothelial cells incubated with RoY peptide at different concentrations and times did not induce VEGF A secretion, nor was there an increase in VEGF receptors Flt-1 and Kdr, as revealed by FACS analysis. Gene expression of VEGF-A, Flt-1 and Kdr were not induced by RoY peptide, and the levels determined by Real Time PCR were not significantly different compared to controls. We have evaluated the angiogenic activity of a novel synthetic proangiogenic peptide. Characterization of the nature of endothelial cell signaling by this peptide will provide the basis for the development of targeted angiogenic therapy.

scholarly journals Basement membrane-like structures containing NTH α1(IV) are formed around the endothelial cell network in a novel in vitro angiogenesis model

2019 ◽  
Vol 317 (2) ◽  
pp. C314-C325
Author(s):  
Yongchol Shin ◽  
Akane Moriya ◽  
Yuta Tohnishi ◽  
Takafumi Watanabe ◽  
Yasutada Imamura
Keyword(s):  
Endothelial Cells ◽  
Basement Membrane ◽  
Blood Vessels ◽  
Type Iv Collagen ◽  
Vascular Endothelial Cells ◽  
Culture Dish ◽  
Cell Network ◽  
Type Iv

Angiogenesis is a process through which new blood vessels are formed by sprouting and elongating from existing blood vessels. Several methods have been used to replicate angiogenesis in vitro, including culturing vascular endothelial cells on Matrigel and coculturing with endothelial cells and fibroblasts. However, the angiogenesis elongation process has not been completely clarified in these models. We therefore propose a new in vitro model of angiogenesis, suitable for observing vascular elongation, by seeding a spheroid cocultured from endothelial cells and fibroblasts into a culture dish. In this model, endothelial cells formed tubular networks elongated from the spheroid with a lumen structure and were connected with tight junctions. A basement membrane (BM)-like structure was observed around the tubular network, similarly to blood vessels in vivo. These results suggested that blood vessel-like structure could be reconstituted in our model. Laminin and type IV collagen, main BM components, were highly localized around the network, along with nontriple helical form of type IV collagen α1-chain [NTH α1(IV)]. In an ascorbic acid-depleted condition, laminin and NTH α1(IV) were observed around the network but not the triple-helical form of type IV collagen and the network was unstable. These results suggest that laminin and NTH α1(IV) are involved in the formation of tubular network and type IV collagen is necessary to stabilize the network.

scholarly journals An inhibitor of endothelial ETS transcription factors promotes physiologic and therapeutic vessel regression

2020 ◽  
Vol 117 (42) ◽  
pp. 26494-26502
Author(s):  
Christopher M. Schafer ◽  
Jami M. Gurley ◽  
Katarzyna Kurylowicz ◽  
Prisca K. Lin ◽  
Wen Chen ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Transcription Factors ◽  
Blood Vessels ◽  
Therapeutic Potential ◽  
Umbilical Vein ◽  
Low Flow ◽  
Ocular Diseases ◽  
Ets Transcription Factors

During the progression of ocular diseases such as retinopathy of prematurity and diabetic retinopathy, overgrowth of retinal blood vessels results in the formation of pathological neovascular tufts that impair vision. Current therapeutic options for treating these diseases include antiangiogenic strategies that can lead to the undesirable inhibition of normal vascular development. Therefore, strategies that eliminate pathological neovascular tufts while sparing normal blood vessels are needed. In this study we exploited the hyaloid vascular network in murine eyes, which naturally undergoes regression after birth, to gain mechanistic insights that could be therapeutically adapted for driving neovessel regression in ocular diseases. We found that endothelial cells of regressing hyaloid vessels underwent down-regulation of two structurally related E-26 transformation-specific (ETS) transcription factors, ETS-related gene (ERG) and Friend leukemia integration 1 (FLI1), prior to apoptosis. Moreover, the small molecule YK-4-279, which inhibits the transcriptional and biological activity of ETS factors, enhanced hyaloid regression in vivo and drove Human Umbilical Vein Endothelial Cells (HUVEC) tube regression and apoptosis in vitro. Importantly, exposure of HUVECs to sheer stress inhibited YK-4-279–induced apoptosis, indicating that low-flow vessels may be uniquely susceptible to YK-4-279–mediated regression. We tested this hypothesis by administering YK-4-279 to mice in an oxygen-induced retinopathy model that generates disorganized and poorly perfused neovascular tufts that mimic human ocular diseases. YK-4-279 treatment significantly reduced neovascular tufts while sparing healthy retinal vessels, thereby demonstrating the therapeutic potential of this inhibitor.

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