Akt-1 Regulates Angiogenesis in Skin.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 845-845
Author(s):  
Tatiana Byzova ◽  
Juhua Chen ◽  
Payaningal R. Somanath
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Blood Vessels ◽  
Cell Function ◽  
Active Form ◽  
Endothelial Cell Migration ◽  
Matrix Composition ◽  
Adhesive Properties ◽  
Endothelial Cell Function

Abstract The major mechanism to adapt to ischemic conditions is the development of neovascularization, i.e. angiogenesis, a process driven by members of VEGF family of growth factors. Phosphoinositide 3-kinase/Akt pathway is a critical component of the signaling network that regulates endothelial cell function related to angiogenesis. VEGF treatment of endothelial cells results in rapid phosphorylation of Akt. Our studies demonstrated that Akt kinase activity is necessary for VEGF-induced and integrin-mediated endothelial cell adhesion and migration. Moreover, cell transfection with a constitutive active form of Akt (myr-Akt) leads to increased function of integrin receptors. Using Akt-1 null mice we found that Akt-1 controls VEGF-induced and integrin-dependent endothelial cell responses in vitro. Impaired endothelial cell migration and adhesion to extracellular matrix and a reduced rate of cell proliferation were observed in Akt-1 (−/−) endothelial cells compared to WT. There are three Akt isoforms with different tissue distribution, however, it appears that Akt-1 is a predominant isoform in skin and in skin microvasculature. This observation prompted us to perform series of in vivo experiments designed to assess the angiogenic response in skin in the absence of Akt-1. Angiogenesis assay using matrigel plugs revealed that the weight and hemoglobin content of matrigel plugs is about two fold higher in Akt (−/−) mice compared to WT mice. Tumor angiogenesis also appears to be enhanced in Akt(−/−) mice, resulting in the significantly lower degree of tumor necrosis. Blood vessels in Akt (−/−) mice appear to be smaller in diameter and have reduced laminin content. Our analysis revealed significant changes in blood vessel wall matrix composition of Akt (−/−) mice as compared to WT animals. These changes resulted in increased vascular permeability in skin of Akt (−/−) mice. Akt-1 is known to target multiple cellular processes including adhesive properties, cell survival, transcription and translation. It appears that the phenotype of Akt-1 (−/−) mice depends on the equilibrium between pro-angiogenic and anti-angiogenic roles of Akt-1 and reveals a central role for Akt-1 in the regulation of matrix production and maturation of blood vessels.

The tetrapeptide AcSDKP, an inhibitor of primitive hematopoietic cell proliferation, induces angiogenesis in vitro and in vivo

Blood ◽  
2003 ◽  
Vol 101 (8) ◽  
pp. 3014-3020 ◽  
Author(s):  
Jian-Miao Liu ◽  
Françoise Lawrence ◽  
Milica Kovacevic ◽  
Jérôme Bignon ◽  
Evangelia Papadimitriou ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Cell Function ◽  
Active Form ◽  
Chorioallantoic Membrane ◽  
Endothelial Cell Migration ◽  
Endothelial Cell Function ◽  
Angiogenic Response ◽  
Matrix Metalloproteinase 1

Abstract The tetrapeptide acetyl-Ser-Asp-Lys-Pro (AcSDKP), purified from bone marrow and constitutively synthesized in vivo, belongs to the family of negative regulators of hematopoiesis. It protects the stem cell compartment from the toxicity of anticancer drugs and irradiation and consequently contributes to a reduction in marrow failure. This current work provides experimental evidence for another novel biologic function of AcSDKP. We report that AcSDKP is a mediator of angiogenesis, as measured by its ability to modulate endothelial cell function in vitro and angiogenesis in vivo. AcSDKP at nanomolar concentrations stimulates in vitro endothelial cell migration and differentiation into capillary-like structures on Matrigel as well as enhances the secretion of an active form of matrix metalloproteinase-1 (MMP-1). In vivo, AcSDKP promotes a significant angiogenic response in the chicken embryo chorioallantoic membrane (CAM) and in the abdominal muscle of the rat. Moreover, it induces the formation of blood vessels in Matrigel plugs implanted subcutaneously in the rat. This is the first report demonstrating the ability of AcSDKP to interact directly with endothelial cells and to elicit an angiogenic response in vitro and in vivo.

High Glucose Alters Endothelial Cell Response to Shear Stress

2009 ◽  
Author(s):  
Steven F. Kemeny ◽  
Alisa Morss Clyne
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Endothelial Cell ◽  
Blood Vessels ◽  
Cell Mechanics ◽  
High Glucose ◽  
Fluid Shear Stress ◽  
Cell Function ◽  
Focal Adhesions ◽  
Endothelial Cell Function

Endothelial cells line the walls of all blood vessels, where they maintain homeostasis through control of vascular tone, permeability, inflammation, and the growth and regression of blood vessels. Endothelial cells are mechanosensitive to fluid shear stress, elongating and aligning in the flow direction [1–2]. This shape change is driven by rearrangement of the actin cytoskeleton and focal adhesions [2]. Hyperglycemia, a hallmark of diabetes, affects endothelial cell function. High glucose has been shown to increase protein kinase C, formation of glucose-derived advanced glycation end-products, and glucose flux through the aldose reductase pathway within endothelial cells [3]. These changes are thought to be related to increased reactive oxygen species production [4]. While endothelial cell mechanics have been widely studied in healthy conditions, many disease states have yet to be explored. Biochemical alterations related to high glucose may alter endothelial cell mechanics.

Comparison of combination treatment with endostatin, soluble neuropilin-1 and thrombospondin-2 to single inhibitors in antiangiogenic therapy of renal cell carcinoma

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 15648-15648
Author(s):  
G. Bartsch ◽  
K. Eggert ◽  
S. Loges ◽  
W. Fiedler ◽  
E. Laack ◽  
...  
Keyword(s):  
Renal Cell Carcinoma ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Function ◽  
Lung Metastases ◽  
Endothelial Cell Function ◽  
Tumor Weight ◽  
Neuropilin 1 ◽  
Angiogenic Inhibitors

15648 Background: Combinations of cytotoxic drugs lead to increased activity and minimize resistance compared to single agents in tumor therapy. Similarly, antiangiogenic treatment could be improved by combinations targeting different pathways. We investigated a combination of endogenous inhibitors using endostatin (ES), soluble Neuropilin-1 (sNP-1), and thrombospondin-2 (TSP-2) in a model of renal cell carcinoma. Methods: Porcine aortic endothelial cells have been engineered for stable production of angiogenic inhibitors by lipofection and were encapsulated in sodium alginate microbeads. Proliferation of human umbilical vein endothelial cells or Renca renal carcinoma cells was examined after incubation with different microbeads. Similarly, effects of inhibitors on endothelial cell function were tested in tube formation and in vitro wound assays. Microbeads were implanted into SCID mice with subcutaneously growing tumors derived from Renca cells or in mice developing lung metastases after intravenous injection of tumor cells. Results: Factors released from microbeads inhibited endothelial cell function but had no effect on tumor cell proliferation in vitro. In vivo, subcutaneous tumor growth was inhibited similarly by each angiogenic inhibitor alone. After 30 days mean tumor weight was 1.3 g in controls and 0.17, 0.18, 0.18g in ES, sNP-1, and TSP-2 treated mice, respectively. Tumor weight in mice treated with all three inhibitors was further reduced to 0.03g. Histological analyses confirmed antiangiogenic activity by inhibition of microvessel density in treated tumors. In a metastastic model treatment with angiogenic inhibitors induced a significant reduction in size and number of lung metastases with additive effects when factors were used in combination. Conclusions: We conclude that combination therapy targeting multiple angiogenic pathways has synergistic activity and could help to avoid resistance to single inhibitors in tumor treatment. No significant financial relationships to disclose.

scholarly journals Effects of HIV-1 gp120 and TAT-derived microvesicles on endothelial cell function

2019 ◽  
Vol 126 (5) ◽  
pp. 1242-1249
Author(s):  
Jamie G. Hijmans ◽  
Kelly Stockelman ◽  
Ma’ayan Levy ◽  
L. Madden Brewster ◽  
Tyler D. Bammert ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Viral Protein ◽  
Cell Function ◽  
Endothelial Damage ◽  
Endothelial Cell Function ◽  
Gp 120 ◽  
Hiv 1

The aims of this study were twofold. The first was to determine if human immunodeficiency virus (HIV)-1 glycoprotein (gp) 120 and transactivator of transcription (Tat) stimulate the release of endothelial microvesicles (EMVs). The second was to determine whether viral protein-induced EMVs are deleterious to endothelial cell function (inducing endothelial cell inflammation, oxidative stress, senescence and increasing apoptotic susceptibility). Human aortic endothelial cells (HAECs) were treated with recombinant HIV-1 proteins Bal gp120 (R5), Lav gp120 (X4), or Tat. EMVs released in response to each viral protein were isolated and quantified. Fresh HAECs were treated with EMVs generated under control conditions and from each of the viral protein conditions for 24 h. EMV release was higher ( P < 0.05) in HAECs treated with R5 (141 ± 21 MV/µl),X4 (132 ± 20 MV/µl), and Tat (130 ± 20 MV/µl) compared with control (61 ± 13 MV/µl). Viral protein EMVs induced significantly higher endothelial cell release of proinflammatory cytokines and expression of cell adhesion molecules than control. Reactive oxygen species production was more pronounced ( P < 0.05) in the R5-, X4- and Tat-EMV-treated cells. In addition, viral protein-stimulated EMVs significantly augmented endothelial cell senescence and apoptotic susceptibility. Concomitant with these functional changes, viral protein-stimulated EMVs disrupted cell expression of micro-RNAs 34a, 126, 146a, 181b, 221, and miR-Let-7a ( P < 0.05). These results demonstrate that HIV-1 gp120 and Tat stimulate microvesicle release from endothelial cells, and these microvesicles confer pathological effects on endothelial cells by inducing inflammation, oxidative stress, and senescence as well as enhancing susceptibility to apoptosis. Viral protein-generated EMVs may contribute to the increased risk of vascular disease in patients with HIV-1.NEW & NOTEWORTHY Human immunodeficiency virus (HIV)-1-related proteins glycoprotein (gp) 120 and transactivator of transcription (Tat)-mediated endothelial damage and dysfunction are poorly understood. Endothelial microvesicles (EMVs) serve as indicators and potent mediators of endothelial dysfunction. In the present study we determined if HIV-1 R5- and X4-tropic gp120 and Tat stimulate EMV release in vitro and if viral protein-induced EMVs are deleterious to endothelial cell function. gp120 and Tat induced a marked increase in EMV release. Viral protein-induced EMVs significantly increased endothelial cell inflammation, oxidative stress, senescence, and apoptotic susceptibility in vitro. gp120- and Tat-derived EMVs promote a proinflammatory, pro-oxidative, prosenescent, and proapoptotic endothelial phenotype and may contribute to the endothelial damage and dysfunction associated with gp120 and Tat.

Isolation, culture, and characterization of rat lung microvascular endothelial cells

1994 ◽  
Vol 267 (4) ◽  
pp. L433-L441 ◽  
Author(s):  
J. C. Magee ◽  
A. E. Stone ◽  
K. T. Oldham ◽  
K. S. Guice
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Function ◽  
Primary Cultures ◽  
Microvascular Endothelial Cells ◽  
Rat Lung ◽  
Simple Method ◽  
Endothelial Cell Function ◽  
Microvascular Endothelial

Highly pure primary cultures of rat lung microvascular endothelial cells were obtained from peripheral lung tissue using a combination of selective culture strategies. The cells had a characteristic morphology consistent with an endothelial origin and were positive for a number of endothelial cell markers, including uptake of fluorescent acetylated lactate dehydrogenase, binding of the lectin Bandeiraea simplicifolia I, and positive immunofluorescence staining with two endothelial cell monoclonal antibodies. The cells behaved as microvascular endothelial cells using an in vitro angiogenesis assay. This isolation method provides a simple method for culturing the pulmonary microvasculature of the rat and these studies support the idea that endothelial cells from different vessels exhibit phenotypic heterogeneity. This method should prove useful for studying specialized endothelial cell function and differentiation in vitro.

scholarly journals Adiponectin Promotes Revascularization of Ischemic Muscle through a Cyclooxygenase 2-Dependent Mechanism

2009 ◽  
Vol 29 (13) ◽  
pp. 3487-3499 ◽  
Author(s):  
Koji Ohashi ◽  
Noriyuki Ouchi ◽  
Kaori Sato ◽  
Akiko Higuchi ◽  
Tomo-o Ishikawa ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Function ◽  
Vascular Diseases ◽  
Adaptor Protein ◽  
Cyclooxygenase 2 ◽  
Endothelial Cell Migration ◽  
Endothelial Cell Function ◽  
Vascular Insufficiency ◽  
Cox 2

ABSTRACT Adiponectin is a fat-derived plasma protein that has cardioprotective roles in obesity-linked diseases. Because cyclooxygenase 2 (COX-2) is an important modulator of endothelial function, we investigated the possible contribution of COX-2 to adiponectin-mediated vascular responses in a mouse hind limb model of vascular insufficiency. Ischemic insult increased COX-2 expression in endothelial cells of wild-type mice, but this induction was attenuated in adiponectin knockout mice. Ischemia-induced revascularization was impaired in mice in which the Cox-2 gene is deleted in Tie2-Cre-expressing cells. Adenovirus-mediated overexpression of adiponectin enhanced COX-2 expression and revascularization of ischemic limbs in control mice, but not in targeted Cox-2-deficient mice. In cultured endothelial cells, adiponectin protein increased COX-2 expression, and ablation of COX-2 abrogated the adiponectin-stimulated increases in endothelial cell migration, differentiation, and survival. Ablation of calreticulin (CRT) or its adaptor protein CD91 diminished adiponectin-stimulated COX-2 expression and endothelial cell responses. These observations provide evidence that adiponectin promotes endothelial cell function through CRT/CD91-mediated increases in COX-2 signaling. Thus, disruption of the adiponectin-COX-2 regulatory axis in endothelial cells could participate in the pathogenesis of obesity-related vascular diseases.

scholarly journals Dysregulation of the EphrinB2−EphB4 ratio in pediatric cerebral arteriovenous malformations is associated with endothelial cell dysfunction in vitro and functions as a novel noninvasive biomarker in patients

2020 ◽  
Vol 52 (4) ◽  
pp. 658-671 ◽  
Author(s):  
Katie Pricola Fehnel ◽  
David L. Penn ◽  
Micah Duggins-Warf ◽  
Maxwell Gruber ◽  
Steven Pineda ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cerebrovascular Disease ◽  
Cell Function ◽  
Index Patient ◽  
Receptor Expression ◽  
Endothelial Cell Function ◽  
Angiogenic Potential ◽  
The Impact

Abstract We investigated (1) EphrinB2 and EphB4 receptor expression in cerebral AVMs, (2) the impact of an altered EphrinB2:EphB4 ratio on brain endothelial cell function and (3) potential translational applications of these data. The following parameters were compared between AVM endothelial cells (AVMECs) and human brain microvascular endothelial cells (HBMVECs): quantified EphrinB2 and EphB4 expression, angiogenic potential, and responses to manipulation of the EphrinB2:EphB4 ratio via pharmacologic stimulation/inhibition. To investigate the clinical relevance of these in vitro data, Ephrin expression was assessed in AVM tissue (by immunohistochemistry) and urine (by ELISA) from pediatric patients with AVM (n = 30), other cerebrovascular disease (n = 14) and control patients (n = 29), and the data were subjected to univariate and multivariate statistical analyses. Compared to HBMVECs, AVMECs demonstrated increased invasion (p = 0.04) and migration (p = 0.08), impaired tube formation (p = 0.06) and increased EphrinB2:EphB4 ratios. Altering the EphrinB2:EphB4 ratio (by increasing EphrinB2 or blocking EphB4) in HBMVECs increased invasion (p = 0.03 and p < 0.05, respectively). EphrinB2 expression was increased in AVM tissue, which correlated with increased urinary EphrinB2 levels in AVM patients. Using the optimal urinary cutoff value (EphrinB2 > 25.7 pg/μg), AVMs were detected with high accuracy (80% vs. controls) and were distinguished from other cerebrovascular disease (75% accuracy). Post-treatment urinary EphrinB2 levels normalized in an index patient. In summary, AVMECs have an EphrinB2:EphB4 ratio that is increased compared to that of normal HBMVECs. Changing this ratio in HBMVECs induces AVMEC-like behavior. EphrinB2 is clinically relevant, and its levels are increased in AVM tissue and patient urine. This work suggests that dysregulation of the EphrinB2:EphB4 signaling cascade and increases in EphrinB2 may play a role in AVM development, with potential utility as a diagnostic and therapeutic target.

scholarly journals Galectins in Endothelial Cell Biology and Angiogenesis: The Basics

Biomolecules ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1386
Author(s):  
Victor Thijssen
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Blood Vessels ◽  
Cell Biology ◽  
Cell Function ◽  
Current Knowledge ◽  
Protein Family ◽  
Endothelial Cell Function ◽  
Inner Surface ◽  
External Cues

Angiogenesis, the growth of new blood vessels out of existing vessels, is a complex and tightly regulated process. It is executed by the cells that cover the inner surface of the vasculature, i.e., the endothelial cells. During angiogenesis, these cells adopt different phenotypes, which allows them to proliferate and migrate, and to form tube-like structures that eventually result in the generation of a functional neovasculature. Multiple internal and external cues control these processes and the galectin protein family was found to be indispensable for proper execution of angiogenesis. Over the last three decades, several members of this glycan-binding protein family have been linked to endothelial cell functioning and to different steps of the angiogenesis cascade. This review provides a basic overview of our current knowledge regarding galectins in angiogenesis. It covers the main findings with regard to the endothelial expression of galectins and highlights their role in endothelial cell function and biology.

scholarly journals The Natural Antioxidants, Pomegranate Extract and Soy Isoflavones, Favourably Modulate Canine Endothelial Cell Function

2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
Sabina M. Baumgartner-Parzer ◽  
Ferdinand Rudolf Waldenberger ◽  
Angelika Freudenthaler ◽  
Amandine Ginouvès-Guerdoux ◽  
David McGahie ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Function ◽  
Soy Isoflavones ◽  
Vascular Endothelial ◽  
Vascular Endothelial Dysfunction ◽  
Endothelial Cell Function ◽  
Proliferation And Apoptosis

Cardiovascular disease, preceded by vascular endothelial dysfunction, is a prominent cause of death in dogs. L-carnitine and taurine, well known for their antioxidative capacity, beneficially affect cardiovascular disease as well as certain dog cardiomyopathies. It is well established that vascular endothelial dysfunction precedes cardiovascular disease and that “vasoprotective factors” (NO and antioxidants) prevent apoptosis, whereas “risk factors” such as oxidized LDL, hyperglycemia, and free fatty acids trigger it in cultured human vascular endothelial cells. Whereas human vascular cell in vitro models are widely established and used for the characterisation of potential vasoprotective substances, such models are not available for canine endothelial cells. In the present study we therefore developed an in vitro model, which allows the testing of the effects of different substances on proliferation and apoptosis in canine aortic endothelial cells. This model was used to test L-carnitine, taurine, pomegranate extract, and Soy Isoflavones in comparison to reference substances (glutathione and pioglitazone) previously shown to modulate human endothelial cell function. L-carnitine and taurine neither exhibited antiproliferative nor antiapoptotic activities in the context of this study. However extracts from pomegranate and soy isoflavones dramatically reduced proliferation and apoptosis in a dose dependent fashion, being in line with a vasoprotective activity in dogs.

scholarly journals Isolation, Characterization, and Transplantation of Cardiac Endothelial Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Busadee Pratumvinit ◽  
Kanit Reesukumal ◽  
Kajohnkiart Janebodin ◽  
Nicholas Ieronimakis ◽  
Morayma Reyes
Keyword(s):  
Flow Cytometry ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Biology ◽  
Cell Function ◽  
Ex Vivo ◽  
Enzymatic Digestion ◽  
Clinical Applications ◽  
Endothelial Cell Function

Isolation andex vivoexpansion of cardiac endothelial cells have been a recurrent challenge due to difficulties in isolation, cell heterogeneity, lack of specific markers to identify myocardial endothelial cells, and inadequate conditions to maintain long-term cultures. Herein, we developed a method for isolation, characterization, and expansion of cardiac endothelial cells applicable to study endothelial cell biology and clinical applications such as neoangiogenesis. First, we dissociated the cells from murine heart by mechanical disaggregation and enzymatic digestion. Then, we used flow cytometry coupled with specific markers to isolate endothelial cells from murine hearts. CD45+ cells were gated out to eliminate the hematopoietic cells. CD31+/Sca-1+ cells were isolated as endothelial cells. Cells isolated from atrium grew faster than those from ventricle. Cardiac endothelial cells maintain endothelial cell function such as vascular tube formation and acetylated-LDL uptakein vitro. Finally, cardiac endothelial cells formed microvessels in dorsal matrigel plug and engrafted in cardiac microvessels following intravenous and intra-arterial injections. In conclusion, our multicolor flow cytometry method is an effective method to analyze and purify endothelial cells from murine heart, which in turn can beex vivoexpanded to study the biology of endothelial cells or for clinical applications such as therapeutic angiogenesis.

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