scholarly journals Arsenic trioxide induces dose- and time-dependent apoptosis of endothelium and may exert an antileukemic effect via inhibition of angiogenesis

Blood ◽  
2000 ◽  
Vol 96 (4) ◽  
pp. 1525-1530 ◽  
Author(s):  
Gail J. Roboz ◽  
Sergio Dias ◽  
George Lam ◽  
William J. Lane ◽  
Steven L. Soignet ◽  
...  

Arsenic trioxide (As2O3) has recently been used successfully in the treatment of acute promyelocytic leukemia and has been shown to induce partial differentiation and apoptosis of leukemic cells in vitro. However, the mechanism by which As2O3 exerts its antileukemic effect remains uncertain. Emerging data suggest that the endothelium and angiogenesis play a seminal role in the proliferation of liquid tumors, such as leukemia. We have shown that activated endothelial cells release cytokines that may stimulate leukemic cell growth. Leukemic cells, in turn, can release endothelial growth factors, such as vascular endothelial growth factor (VEGF). On the basis of these observations, we hypothesized that As2O3 may interrupt a reciprocal loop between leukemic cells and the endothelium by direct action on both cell types. We have shown that treatment of proliferating layers of human umbilical vein endothelial cells (HUVECs) with a variety of concentrations of As2O3results in a reproducible dose- and time-dependent sequence of events marked by change to an activated morphology, up-regulation of endothelial cell adhesion markers, and apoptosis. Also, treatment with As2O3 caused inhibition of VEGF production in the leukemic cell line HEL. Finally, incubation of HUVECs with As2O3 prevented capillary tubule and branch formation in an in vitro endothelial cell–differentiation assay. In conclusion, we believe that As2O3 interrupts a reciprocal stimulatory loop between leukemic cells and endothelial cells by causing apoptosis of both cell types and by inhibiting leukemic cell VEGF production.

Blood ◽  
2000 ◽  
Vol 96 (4) ◽  
pp. 1525-1530 ◽  
Author(s):  
Gail J. Roboz ◽  
Sergio Dias ◽  
George Lam ◽  
William J. Lane ◽  
Steven L. Soignet ◽  
...  

Abstract Arsenic trioxide (As2O3) has recently been used successfully in the treatment of acute promyelocytic leukemia and has been shown to induce partial differentiation and apoptosis of leukemic cells in vitro. However, the mechanism by which As2O3 exerts its antileukemic effect remains uncertain. Emerging data suggest that the endothelium and angiogenesis play a seminal role in the proliferation of liquid tumors, such as leukemia. We have shown that activated endothelial cells release cytokines that may stimulate leukemic cell growth. Leukemic cells, in turn, can release endothelial growth factors, such as vascular endothelial growth factor (VEGF). On the basis of these observations, we hypothesized that As2O3 may interrupt a reciprocal loop between leukemic cells and the endothelium by direct action on both cell types. We have shown that treatment of proliferating layers of human umbilical vein endothelial cells (HUVECs) with a variety of concentrations of As2O3results in a reproducible dose- and time-dependent sequence of events marked by change to an activated morphology, up-regulation of endothelial cell adhesion markers, and apoptosis. Also, treatment with As2O3 caused inhibition of VEGF production in the leukemic cell line HEL. Finally, incubation of HUVECs with As2O3 prevented capillary tubule and branch formation in an in vitro endothelial cell–differentiation assay. In conclusion, we believe that As2O3 interrupts a reciprocal stimulatory loop between leukemic cells and endothelial cells by causing apoptosis of both cell types and by inhibiting leukemic cell VEGF production.


1987 ◽  
Vol 245 (1) ◽  
pp. 151-157 ◽  
Author(s):  
E R Hall ◽  
C E Manner ◽  
J Carinhas ◽  
R Snopko ◽  
M Rafelson

The asymmetric distribution of phospholipids in bovine endothelial-cell membranes was probed with 2,4,6-trinitrobenzenesulphonate and purified phospholipase A2. The data suggest that phosphotidylethanolamine is primarily located in the inner lipid bilayer, as reported for other cell types. Stearic acid is taken up by the endothelial cells and is randomly distributed among the membrane phospholipids. In contrast, the polyunsaturated fatty acids (arachidonic, eicosatrienoic and eicosapentaenoic acids) have initial incorporation into the phosphatidylcholine fraction. These fatty acids then undergo a time-dependent transfer from phosphatidylcholine to phosphatidylethanolamine. Thus we propose that endothelial cells possess a mechanism for the selective internalization of polyunsaturated fatty acids.


Blood ◽  
1988 ◽  
Vol 71 (1) ◽  
pp. 99-103 ◽  
Author(s):  
KM Zsebo ◽  
VN Yuschenkoff ◽  
S Schiffer ◽  
D Chang ◽  
E McCall ◽  
...  

Abstract Cultured mononuclear phagocytes produce soluble factors that stimulate endothelial cells to release GM-colony-stimulating activity (GM-CSA). One such factor was recently identified as interleukin 1 (IL 1). Studies were designed to determine which types of granulopoietic factors are released by IL 1-stimulated endothelial cells. Supernatants from endothelial cells cultured for 3 days in medium containing IL 1 alpha and beta were tested in both murine and human CFU-GM colony growth assays. The effect of conditioned media on differentiation of WEHI-3B myelomonocytic leukemic cells was also examined. Control media containing IL 1 alone or unstimulated endothelial cell-conditioned media contained no detectable CSA in any bioassay. Medium conditioned by IL 1-stimulated endothelial cells stimulated the clonal growth of both human and murine CFU-GM and induced macrophage differentiation of WEHI-3B cells. Treatment of these conditioned media with a highly specific neutralizing monoclonal G-CSF antibody completely inhibited their activity in the murine CFU-GM assay, but only partially inhibited GM colony growth by human marrow. Treatment of the active conditioned media with a neutralizing rabbit anti-human GM-CSF antibody partially reduced the activity of the media in the human GM-colony growth assay. G-CSF radioimmunoassay of endothelial cell culture supernatants and Northern blot analysis of endothelial cell cytoplasmic RNA for GM-CSF gene transcripts confirmed that IL 1 induced expression of both G-CSF and GM-CSF genes. Because treatment of media with both antibodies abrogated all activity in the human GM colony growth assay, we conclude that IL 1-stimulated endothelial cells release both G and GM-CSF and that these are the only granulopoietic factors detectable in clonogenic assays released by these cells in vitro.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 5324-5324
Author(s):  
Jennifer L. McNeer ◽  
Blazej Dolniak ◽  
Barbara Kroczynska ◽  
Antonella Sassano ◽  
Leonidas Platanias

Abstract Arsenic Trioxide (As2O3) has major efficacy in the treatment of acute promyelocytic leukemia (APL), but its use in other malignancies is limited by the need for high intracellular concentrations to induce apoptosis. Prior work in our laboratory has demonstrated that the p38 MAP kinase (MAPK) pathway is activated following treatment of cells with As2O3 and exhibits negative regulatory effects on As2O3-induced apoptosis and growth suppression. In the current study, we sought to identify upstream effector mechanisms by which the p38 pathway is activated by As2O3 in leukemic cells. We found that the MAPK kinase kinase TAO2 (thousand and one amino acid protein kinase 2) is phosphorylated on Ser181 after treatment of NB4, NB4.306, and U937 cells with arsenic. Such phosphorylation was rapid, occurring as early as after 5 minutes of As2O3 treatment. In addition, our data indicate that such phosphorylation occurs downstream of As2O3-induced redox reactions, as demonstrated by increased phosphorylation in cells pretreated with the oxidizing agent buthionine sulfoximine (BSO) and decreased phosphorylation following pretreatment with the reducing agent dithiothreitol (DTT). Arsenic treatment of the cells also resulted in activation of the kinase domain of TAO2, as evidenced in in vitro kinase assay studies using ATF2 as an exogenous substrate. siRNA-mediated TAO2 knockdown resulted in inhibition of As2O3-induced p38 phosphorylation, suggesting that this kinase acts as an upstream effector of the arsenic-activated p38 MAPK pathway. Moreover, in studies to determine the functional relevance of TAO2 in the induction of As2O3-dependent antileukemic responses we found that siRNA-mediated TAO2 knockdown enhanced the suppressive effects of As2O3 on KT1-derived leukemic progenitor (CFU-L) growth in clonogenic assays in methylcellulose. Altogether, our data demonstrate that TAO2 is activated during arsenic treatment of leukemic cells lines and acts as an upstream activator of the p38 MAPK pathway. Such activation appears to occur in a negative feedback regulatory manner to compensate for the suppressive effects of As2O3 on leukemic cell growth. Importantly, these findings raise the possibility that targeting TAO2 may provide a novel approach to enhance the generation of the antileukemic properties of As2O3.


2001 ◽  
Vol 281 (3) ◽  
pp. L529-L533 ◽  
Author(s):  
Aron B. Fisher ◽  
Shu Chien ◽  
Abdul I. Barakat ◽  
Robert M. Nerem

Endothelial cells are normally exposed constantly to mechanical forces that significantly influence their phenotype. This symposium presented recent information concerning endothelial cell responses to shear stress associated with blood flow. Endothelial cell shear stress mechanosensors that have been proposed include membrane receptor kinases, integrins, G proteins, ion channels, intercellular junction proteins, membrane lipids (e.g., those associated with caveolae), and the cytoskeleton. These sensors are linked to signaling cascades that interact with or result in generation of reactive oxygen species, nitric oxide, and various transcription factors among other responses. Endothelial cells adapt to sustained shear stress, and either an increase or decrease from normal shear leads to signaling events. In vitro models for the study of endothelial cell responses must consider the pattern of shear stress (e.g., steady vs. oscillatory flow), the scaffold for cell growth (e.g., basement membrane or other cell types such as smooth muscle cells), and the extent of flow adaptation. These cellular responses have major relevance for understanding the pathophysiological effects of increased shear stress associated with hypertension or decreased shear stress associated with thrombotic occlusion.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
V F M Segers ◽  
Z Vermeulen ◽  
L Mateiu ◽  
L Dugaucquier ◽  
G W De Keulenaer

Abstract Background Cardiac microvascular endothelial cells (CMVECs) are the most numerous cells in the myocardium and orchestrate cardiogenesis during development, regulate adult cardiac function, and modulate pathophysiology of heart failure. It has been shown that the transcriptome of CMVECs differs from other endothelial cell types, but transcriptomic changes in cardiac endothelial cells during cardiac maturation and cardiac remodeling have not been studied earlier. Purpose To study changes in the transcriptome of CMVECs during cardiac maturation and cardiac remodeling, and to test the hypothesis that the fetal gene program is reactivated during cardiac remodeling in CVMECs. Methods CMVECs were isolated from rat hearts based on CD31 expression and were immediately processed for RNA sequencing, without an in vitro propagation step. We compared gene expression levels from primary CMVECs of neonatal hearts, normal adult hearts, and infarcted-hearts (4 weeks post LAD ligation). Results Between neonatal and adult CMVECs, 6838 genes were differentially expressed indicating that CMVECs undergo a substantial transformation during postnatal cardiac growth. A large fraction of genes upregulated in neonatal CMVECs are part of mitosis pathways, whereas a large fraction of genes upregulated in adult CMVECs are part of cellular response, secretory, signaling, and cell adhesion pathways. Between CMVECs of normal adult hearts and infarcted hearts, 159 genes were differentially expressed. We found a limited degree of overlap (55 genes) between the differentially expressed genes in neonatal and infarcted-hearts. Of 46 significantly upregulated genes in the infarcted heart, 46% were also upregulated in neonatal hearts relative to sham. Of 113 significantly downregulated genes in the infarcted-hearts, 30% were also downregulated in neonatal hearts relative to sham. Conclusion These data demonstrate that CMVECs undergo dramatic changes from neonatal to adult and more subtle changes between normal state and cardiac remodeling. During cardiac remodeling, a small part of the fetal gene program is reactivated in CMVECs. Acknowledgement/Funding IOF/SBO research grant (PID34923), Fund for Scientific Research Flanders (Application numbers 1501118N and 1842219N).


Blood ◽  
1988 ◽  
Vol 71 (1) ◽  
pp. 99-103 ◽  
Author(s):  
KM Zsebo ◽  
VN Yuschenkoff ◽  
S Schiffer ◽  
D Chang ◽  
E McCall ◽  
...  

Cultured mononuclear phagocytes produce soluble factors that stimulate endothelial cells to release GM-colony-stimulating activity (GM-CSA). One such factor was recently identified as interleukin 1 (IL 1). Studies were designed to determine which types of granulopoietic factors are released by IL 1-stimulated endothelial cells. Supernatants from endothelial cells cultured for 3 days in medium containing IL 1 alpha and beta were tested in both murine and human CFU-GM colony growth assays. The effect of conditioned media on differentiation of WEHI-3B myelomonocytic leukemic cells was also examined. Control media containing IL 1 alone or unstimulated endothelial cell-conditioned media contained no detectable CSA in any bioassay. Medium conditioned by IL 1-stimulated endothelial cells stimulated the clonal growth of both human and murine CFU-GM and induced macrophage differentiation of WEHI-3B cells. Treatment of these conditioned media with a highly specific neutralizing monoclonal G-CSF antibody completely inhibited their activity in the murine CFU-GM assay, but only partially inhibited GM colony growth by human marrow. Treatment of the active conditioned media with a neutralizing rabbit anti-human GM-CSF antibody partially reduced the activity of the media in the human GM-colony growth assay. G-CSF radioimmunoassay of endothelial cell culture supernatants and Northern blot analysis of endothelial cell cytoplasmic RNA for GM-CSF gene transcripts confirmed that IL 1 induced expression of both G-CSF and GM-CSF genes. Because treatment of media with both antibodies abrogated all activity in the human GM colony growth assay, we conclude that IL 1-stimulated endothelial cells release both G and GM-CSF and that these are the only granulopoietic factors detectable in clonogenic assays released by these cells in vitro.


1998 ◽  
Vol 95 (16) ◽  
pp. 9454-9458 ◽  
Author(s):  
Armen B. Shanafelt ◽  
Carla P. Forte ◽  
James J. Kasper ◽  
Lisa Sanchez-Pescador ◽  
Monte Wetzel ◽  
...  

Interleukin 4 (IL-4) is a pleiotropic cytokine. Of the cell types responsive to IL-4, T cells express one IL-4 receptor (IL-4R) type, IL-4Rα/IL-2Rγ (class I IL-4R), whereas endothelial cells express another type, IL-4Rα/IL-13Rα (class II IL-4R). It was hypothesized that IL-4 variants could be generated that would be selective for cell types expressing the different IL-4Rs. A series of IL-4 muteins were generated that were substituted in the region of IL-4 implicated in interactions with IL-2Rγ. These muteins were evaluated in T cell and endothelial cell assays. One of these muteins, containing the mutation Arg-121 to Glu (IL-4/R121E), exhibited complete biological selectivity for T cells, B cells, and monocytes, but showed no activity on endothelial cells. Receptor binding studies indicated that IL-4/R121E retained physical interaction with IL-2Rγ but not IL-13Rα; consistent with this observation, IL-4/R121E was an antagonist of IL-4-induced activity on endothelial cells. IL-4/R121E exhibits a spectrum of activitiesin vitrothat suggest utility in the treatment of certain autoimmune diseases.


1979 ◽  
Author(s):  
S. Korach ◽  
D. Ngo

Adult pig aortas, sectioned longitudinally, were incubated in 0.1% collagenase-PBS (15 mn, 37°C). Gentle scraping of the lumenal surface resulted in high yields (3-4 x 106 cell/aorta) of viable endothelial cells, essentially devoid of other cell types by morphological and immunochemical (F VIII-antigen) criteria. Confluent monolayers were incubated for various times (5 mn to 1 wk) with decomplemented rabbit antisera raised against pig endothelial cells. Changes in cell morphology appeared to depend on antibody concentration rather than on duration of contact with antiserum. High concentrations of antiserum (5 to 20%) led to cytoplasmic shredding, bulging of cells and extensive vacuolization, whereas at lower concentrations, cells appeared almost normal. Transmission EM studies by the indirect immunoperoxydase method showed antibodies reacting with unfixed cells to be distributed all over the upper cell surface, in the outer parts of intercellular junctions, and within numerous pinocytotic vesicles. Much weaker reactions could also be seen at the lower cell surface. When viewed under the Scanning EM, antiserum-treated endothelial cells also disclosed antibody concentration-dependent bulging and release of cells from their substrate. In vitro studies of gradual modifications of vascular endothelial cells acted upon by antibodies should provide a better understanding of the structural and biochemical processes underlying endothelial damage and detachment.


2021 ◽  
Vol 22 (2) ◽  
pp. 978
Author(s):  
Skadi Lau ◽  
Manfred Gossen ◽  
Andreas Lendlein ◽  
Friedrich Jung

Although cardiovascular devices are mostly implanted in arteries or to replace arteries, in vitro studies on implant endothelialization are commonly performed with human umbilical cord-derived venous endothelial cells (HUVEC). In light of considerable differences, both morphologically and functionally, between arterial and venous endothelial cells, we here compare HUVEC and human umbilical cord-derived arterial endothelial cells (HUAEC) regarding their equivalence as an endothelial cell in vitro model for cardiovascular research. No differences were found in either for the tested parameters. The metabolic activity and lactate dehydrogenase, an indicator for the membrane integrity, slightly decreased over seven days of cultivation upon normalization to the cell number. The amount of secreted nitrite and nitrate, as well as prostacyclin per cell, also decreased slightly over time. Thromboxane B2 was secreted in constant amounts per cell at all time points. The Von Willebrand factor remained mainly intracellularly up to seven days of cultivation. In contrast, collagen and laminin were secreted into the extracellular space with increasing cell density. Based on these results one might argue that both cell types are equally suited for cardiovascular research. However, future studies should investigate further cell functionalities, and whether arterial endothelial cells from implantation-relevant areas, such as coronary arteries in the heart, are superior to umbilical cord-derived endothelial cells.


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