scholarly journals Hypoxia Does neither Stimulate Pulmonary Artery Endothelial Cell Proliferation in Mice and Rats with Pulmonary Hypertension and Vascular Remodeling nor in Human Pulmonary Artery Endothelial Cells

2011 ◽  
Vol 48 (6) ◽  
pp. 465-475 ◽  
Author(s):  
Lunyin Yu ◽  
Charles A. Hales
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Pulmonary Hypertension ◽  
Endothelial Cell ◽  
Pulmonary Artery ◽  
Vascular Remodeling ◽  
Endothelial Cell Proliferation ◽  
Human Pulmonary Artery ◽  
Pulmonary Artery Endothelial Cell

Notch2 Suppression Mimicking Changes in Human Pulmonary Hypertension Modulates Notch1 and Promotes Endothelial Cell Proliferation

2021 ◽  
Author(s):  
Sanghamitra Sahoo ◽  
Yao Li ◽  
Daniel de Jesus ◽  
John Charles Sembrat II ◽  
Mauricio M Rojas ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Target Genes ◽  
Pulmonary Arteries ◽  
Notch Receptor ◽  
Endothelial Cell Proliferation ◽  
Tissue Samples ◽  
Endothelial Proliferation ◽  
Human Pulmonary Artery

Pulmonary arterial hypertension (PAH) is a fatal cardiopulmonary disease characterized by increased vascular cell proliferation with resistance to apoptosis and occlusive remodeling of the small pulmonary arteries in humans. The Notch family of proteins are proximal signaling mediators of an evolutionarily conserved pathway that effect cell proliferation, fate determination, and development. In endothelial cells (ECs), Notch receptor 2 (Notch2) has been shown to promote endothelial apoptosis. However, a pro- or anti-proliferative role for Notch2 in pulmonary endothelial proliferation and ensuing PAH is unknown. Herein, we postulated that suppressed Notch2 signaling drives pulmonary endothelial proliferation in the setting of PAH. We observed that levels of Notch2 are ablated in lung and PA tissue samples from PAH patients compared to non-PAH controls. Interestingly, Notch2 expression was attenuated in human pulmonary artery endothelial cells (hPAECs) exposed to vasoactive factors including hypoxia, TGFβ, ET-1, and IGF-1. Gene silencing of Notch2 increased EC proliferation and reduced apoptosis. At the molecular level, Notch2-deficient hPAECs activated Akt, Erk1/2 and anti-apoptotic protein Bcl-2, and reduced levels of p21cip and Bax. Intriguingly, loss of Notch2 elicits a paradoxical activation of Notch1 and transcriptional upregulation of canonical Notch target genes Hes1, Hey1 and Hey2. Further, reduction in Rb and increased E2F1 binding to the Notch1 promoter appear to explain the upregulation of Notch1. In aggregate, our results demonstrate that loss of Notch2 derepresses Notch1 and elicits aberrant EC hallmarks of PAH. The data underscore a novel role for Notch in the maintenance of endothelial cell homeostasis.

Lung endothelial cell proliferation in normal and pulmonary hypertensive neonatal calves

1998 ◽  
Vol 275 (3) ◽  
pp. L593-L600 ◽  
Author(s):  
Leopold Stiebellehner ◽  
James K. Belknap ◽  
Beverly Ensley ◽  
Alan Tucker ◽  
E. Christopher Orton ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Pulmonary Artery ◽  
Main Pulmonary Artery ◽  
Endothelial Cell Proliferation ◽  
Hemodynamic Changes ◽  
Vascular Segment ◽  
Neonatal Calves

Tremendous changes in pressure and flow occur in the pulmonary and systemic circulations after birth, and these hemodynamic changes should markedly affect endothelial cell replication. However, in vivo endothelial replication rates in the neonatal period have not been reported. To label replicating endothelial cells, we administered the thymidine analog bromodeoxyuridine to calves ∼1, 4, 7, 10, and 14 days old before they were killed. Because we expected the ratio of replicating to nonreplicating cells to vary with vascular segment, we examined the main pulmonary artery, a large elastic artery, three sizes of intrapulmonary arteries, the aorta, and the carotid artery. In normoxia for arteries < 1,500 μm, ∼27% of the endothelial cells were labeled on day 1 but only ∼2% on day 14. In the main pulmonary artery, only ∼4% of the endothelial cells were labeled on day 1 and ∼2% on day 14. In contrast, in the aorta, ∼12% of the endothelial cells were labeled on day 1 and ∼2% on day 14. In chronically hypoxic animals, only ∼14% of the endothelial cells were labeled on day 1 in small lung arteries and ∼8% were still labeled on day 14. We conclude that the postnatal circulatory adaptation to extrauterine life includes significant changes in endothelial cell proliferation that vary dramatically with time and vascular location and that these changes are altered in chronic hypoxia.

scholarly journals Chronic Hypoxia Promotes Pulmonary Artery Endothelial Cell Proliferation through H2O2-Induced 5-Lipoxygenase

PLoS ONE ◽  
2014 ◽  
Vol 9 (6) ◽  
pp. e98532 ◽  
Author(s):  
Kristi M. Porter ◽  
Bum-Yong Kang ◽  
Sherry E. Adesina ◽  
Tamara C. Murphy ◽  
C. Michael Hart ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cell ◽  
Pulmonary Artery ◽  
Chronic Hypoxia ◽  
Endothelial Cell Proliferation ◽  
Pulmonary Artery Endothelial Cell

5-Lipoxygenase and human pulmonary artery endothelial cell proliferation

2002 ◽  
Vol 282 (2) ◽  
pp. H585-H593 ◽  
Author(s):  
Jennifer L. Walker ◽  
Joseph Loscalzo ◽  
Ying-Yi Zhang
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cell ◽  
Pulmonary Artery ◽  
Transfection Efficiency ◽  
Nordihydroguaiaretic Acid ◽  
Cell Counting ◽  
Endothelial Cell Proliferation ◽  
Dependent Manner ◽  
Lactate Dehydrogenase Release ◽  
Human Pulmonary Artery

Increased 5-lipoxygenase (5LO) expression in pulmonary artery endothelial cells (PAECs) has been observed in primary pulmonary hypertension, a disorder associated with pulmonary vascular remodeling and aberrant endothelial cell proliferation. To examine whether 5LO plays a role in endothelial cell proliferation, we analyzed the effect of 5LO inhibitors on cultured human PAECs. Analysis of [3H]thymidine incorporation showed that 5LO and 5LO-activating protein inhibitors AA-861, nordihydroguaiaretic acid (NDGA), and MK-886 all inhibited PAEC growth in a dose-dependent manner, with maximal inhibition of >90% and IC50values of 3.9, 1.8, and 0.48 μM, respectively. The effect of AA-861 and NDGA correlated with their effect on 5LO activity in PAECs. Concentrations of these inhibitors at or below their IC90values did not cause significant cell death as determined by lactate dehydrogenase release, but decreased cell doubling, as measured by cell counting at 24 h after serum replenishment. Analysis of DNA content suggested that the inhibitors led to an accumulation of PAECs at the G0/G1phase. Antisense oligonucleotides to 5LO mRNA delivered at a transfection efficiency of ∼60% inhibited cell growth by 40 ± 26% compared with that of a sequence-unrelated oligonucleotide. Indomethacin had no effect on PAEC growth over a range of concentrations (0.3–5 μM). These data show that 5LO inhibitors impaired the proliferative response of the cultured PAECs, suggesting that this enzyme may contribute to PAEC growth under certain pathological conditions.

scholarly journals Raf/ERK drives the proliferative and invasive phenotype of BMPR2-silenced pulmonary artery endothelial cells

2016 ◽  
Vol 310 (2) ◽  
pp. L187-L201 ◽  
Author(s):  
Keytam S. Awad ◽  
Jason M. Elinoff ◽  
Shuibang Wang ◽  
Salina Gairhe ◽  
Gabriela A. Ferreyra ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Pulmonary Artery ◽  
Vascular Remodeling ◽  
Kinase Inhibitor ◽  
Erk Signaling ◽  
Cell Phenotype ◽  
Loss Of Function ◽  
Morphogenetic Protein ◽  
Human Pulmonary Artery

A proliferative endothelial cell phenotype, inflammation, and pulmonary vascular remodeling are prominent features of pulmonary arterial hypertension (PAH). Bone morphogenetic protein type II receptor (BMPR2) loss-of-function is the most common cause of heritable PAH and has been closely linked to the formation of pathological plexiform lesions. Although some BMPR2 mutations leave ligand-dependent responses intact, the disruption of ligand-independent, noncanonical functions are universal among PAH-associated BMPR2 genotypes, but incompletely understood. This study examined the noncanonical signaling consequences of BMPR2 silencing in human pulmonary artery endothelial cells to identify potential therapeutic targets. BMPR2 siRNA silencing resulted in a proliferative, promigratory pulmonary artery endothelial cell phenotype and disruption of cytoskeletal architecture. Expression profiling closely reflected these phenotypic changes. Gene set enrichment and promoter analyses, as well as the differential expression of pathway components identified Ras/Raf/ERK signaling as an important consequence of BMPR2 silencing. Raf family members and ERK1/2 were constitutively activated after BMPR2 knockdown. Two Raf inhibitors, sorafenib and AZ628, and low-dose nintedanib, a triple receptor tyrosine kinase inhibitor upstream from Ras, reversed the abnormal proliferation and hypermotility of BMPR2 deficiency. Inhibition of dysregulated Ras/Raf/ERK signaling may be useful in reversing vascular remodeling in PAH.

Mechanism of ATP-induced leukocyte adherence to cultured pulmonary artery endothelial cells

1996 ◽  
Vol 270 (5) ◽  
pp. L695-L703 ◽  
Author(s):  
A. L. Parker ◽  
L. L. Likar ◽  
D. D. Dawicki ◽  
S. Rounds
Keyword(s):  
Endothelial Cells ◽  
Cell Adhesion ◽  
Endothelial Cell ◽  
Pulmonary Artery ◽  
Platelet Activating Factor ◽  
Human Neutrophils ◽  
Neutrophil Adherence ◽  
Human Pulmonary Artery ◽  
Pulmonary Artery Endothelial Cell ◽  
Endothelial Cell Adhesion

Previously we have shown that ATP enhances the adherence of HL-60 cells and human neutrophils to bovine pulmonary artery endothelial cells. The current investigations extend earlier findings by showing that ATP and UTP dose-dependently stimulate human neutrophil adherence to human pulmonary artery endothelial cells. We have also explore the mechanisms of ATP- and UTP-stimulated adherence. We have found that fucose, a component of selectin receptors, inhibits ATP-stimulated HL-60 cell-bovine pulmonary artery endothelial cell adhesion. Additionally, pretreatment of HL-60 cells with neuraminidase abolishes ATP enhancement. However, fucose does not affect ATP- or thrombin-induced adhesion of freshly isolated human neutrophils to human endothelial cells. Antibodies to human P-selection intercellular adhesion molecule (ICAM)-1, and the beta-subunit of CD11/CD18 do not alter ATP-induced adherence of HL-60 cells to bovine endothelial cells. Similarly, antibodies to human P-selectin and ICAM-1 do not inhibit human neutrophil-human pulmonary artery endothelial cell adhesion. The platelet-activating factor receptor antagonists, WEB-2086 and L-659,989, are effective in attenuating ATP- and UTP-stimulated adherence. Preincubation of neutrophils or human pulmonary artery endothelial cells with ATP or UTP also enhances adherence, an effect that is blocked by L-659,989. Thus platelet activating factor, associated with both neutrophils and endothelial cells, mediates ATP- and UTP-induced neutrophil adherence. ATP, released during vascular injury, may exacerbate neutrophil-endothelial cell interaction and thereby contribute to neutrophil-induced injury.

Effect of Native and Cleaved Forms of Antithrombin on Nuclear Factor κB Activation in Endothelial Cells.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3923-3923
Author(s):  
Hongyu Ni ◽  
Balwant Chauhan ◽  
Steven Olson
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Pulmonary Artery ◽  
Nuclear Factor Κb ◽  
Coagulation Cascade ◽  
Endothelial Cell Proliferation ◽  
Nuclear Factor ◽  
Single Chain ◽  
Anti Inflammatory

Abstract Antithrombin (AT) is a single chain plasma glycoprotein that belongs to a superfamily of serine protease inhibitors (Serpin). AT is the major inhibitor of the serine proteases of the coagulation cascade, notably thrombin and factor Xa. In addition, AT has also been demonstrated to have anti-inflammatory properties. Recently, cleaved and latent forms of AT have been shown to function as antiangiogenic agents. However, the molecular mechanisms by which native AT and cleaved AT exert their anti-inflammatory and antiangiogenic effects remains unknown. In this study, we have investigated the effects of both native and cleaved forms of AT on endothelial cell proliferation and nuclear factor κB (NF-κB) activation in the endothelial cells. Bovine pulmonary artery endothelial cells (BPAE) was used in the study. Human α-antithrombin was purified from plasma by affinity chromatography on heparin Sepharose, followed by anion-exchange chromatography. Cleaved form of AT was prepared by digestion of purified human AT with human neutrophil elastase, followed by chromatography on a heparin Sepharose column. The endothelial cells were stimulated with basic fibroblast growth factor (bFGF) or tumor necrosis factor-α (TNF-α) in culture and incubated with either native AT or cleaved AT. Endothelial cell proliferation was measured by the MTT (methylthiazolyldiphenyl-tetrazolium bromide) cell proliferation assay as well as by counting cell numbers before and after the treatment. The results demonstrate that both native AT and cleaved AT could inhibit bovine pulmonary artery endothelial cell proliferation. These results contrast with those reported with other types of endothelial cells such as human umbilical vein endothelial cells (HUVEC) in which only cleaved form but not native form of AT inhibits cell proliferation. NF-κB activation was detected by the ELISA-based assay using antibodies specific for the activated form of p50 and p65 subunit of the NF-κB. In native AT, the inhibitory activity of endothelial cell proliferation was associated with down-regulation of NF-κB as measured by decreased nuclear p65. However, the cleaved AT showed minimal effect on the NF-κB activation. Our results suggest that although both native and cleaved AT inhibit endothelial cell proliferation, they might use different signal transduction pathways. Moreover, our findings suggest that native and cleaved AT may have differential effects on different types of endothelial cells.

Abstract 117: RhoC Regulates VEGF-induced Signaling in Endothelial Cells

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Luke Hoeppner ◽  
Sutapa Sinha ◽  
Ying Wang ◽  
Resham Bhattacharya ◽  
Shamit Dutta ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Vascular Permeability ◽  
Rho Gtpase ◽  
Endothelial Cell Migration ◽  
Calcium Flux ◽  
Endothelial Cell Proliferation ◽  
Vegf Receptor ◽  
Vegf Signaling

Vascular permeability factor/vascular endothelial growth factor A (VEGF) is a central regulator of angiogenesis and potently promotes vascular permeability. VEGF plays a key role in the pathologies of heart disease, stroke, and cancer. Therefore, understanding the molecular regulation of VEGF signaling is an important pursuit. Rho GTPase proteins play various roles in vasculogenesis and angiogenesis. While the functions of RhoA and RhoB in these processes have been well defined, little is known about the role of RhoC in VEGF-mediated signaling in endothelial cells and vascular development. Here, we describe how RhoC modulates VEGF signaling to regulate endothelial cell proliferation, migration and permeability. We found VEGF stimulation activates RhoC in human umbilical vein endothelial cells (HUVECs), which was completely blocked after VEGF receptor 2 (VEGFR-2) knockdown indicating that VEGF activates RhoC through VEGFR-2 signaling. Interestingly, RhoC knockdown delayed the degradation of VEGFR-2 compared to control siRNA treated HUVECs, thus implicating RhoC in VEGFR-2 trafficking. In light of our results suggesting VEGF activates RhoC through VEGFR-2, we sought to determine whether RhoC regulates vascular permeability through the VEGFR-2/phospholipase Cγ (PLCγ) /Ca 2+ /eNOS cascade. We found RhoC knockdown in VEGF-stimulated HUVECs significantly increased PLC-γ1 phosphorylation at tyrosine 783, promoted basal and VEGF-stimulated eNOS phophorylation at serine 1177, and increased calcium flux compared with control siRNA transfected HUVECs. Taken together, our findings suggest RhoC negatively regulates VEGF-induced vascular permeability. We confirmed this finding through a VEGF-inducible zebrafish model of vascular permeability by observing significantly greater vascular permeability in RhoC morpholino (MO)-injected zebrafish than control MO-injected zebrafish. Furthermore, we showed that RhoC promotes endothelial cell proliferation and negatively regulates endothelial cell migration. Our data suggests a scenario in which RhoC promotes proliferation by upregulating -catenin in a Wnt signaling-independent manner, which in turn, promotes Cyclin D1 expression and subsequently drives cell cycle progression.

The role of matrix metalloproteinase activity in the maturation of human capillary endothelial cells in vitro

1999 ◽  
Vol 112 (10) ◽  
pp. 1599-1609 ◽  
Author(s):  
B.M. Kraling ◽  
D.G. Wiederschain ◽  
T. Boehm ◽  
M. Rehn ◽  
J.B. Mulliken ◽  
...  
Keyword(s):  
Cell Culture ◽  
Cell Proliferation ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Endothelial Cell Proliferation ◽  
Protein Levels ◽  
Matrix Deposition ◽  
Capillary Endothelial Cells ◽  
Vessel Maturation

Vessel maturation during angiogenesis (the formation of new blood vessels) is characterized by the deposition of new basement membrane and the downregulation of endothelial cell proliferation in the new vessels. Matrix remodeling plays a crucial, but still poorly understood role, in angiogenesis regulation. We present here a novel assay system with which to study the maturation of human capillary endothelial cells in vitro. When human dermal microvascular endothelial cells (HDMEC) were cultured in the presence of dibutyryl cAMP (Bt2) and hydrocortisone (HC), the deposition of a fibrous lattice of matrix molecules consisting of collagens type IV, type XVIII, laminin and thrombospondin was induced. In basal medium (without Bt2 and HC), HDMEC released active matrix metalloproteinases (MMPs) into the culture medium. However, MMP protein levels were significantly reduced by treatment with Bt2 and HC, while protein levels and activity of endogenous tissue inhibitor of MMPs (TIMP) increased. This shift in the proteolytic balance and matrix deposition was inhibited by the specific protein kinase A inhibitors RpcAMP and KT5720 or by substituting analogues without reported glucocorticoid activity for HC. The addition of MMP inhibitors human recombinant TIMP-1 or 1,10-phenanthroline to cultures under basal conditions induced matrix deposition in a dose-dependent manner, which was not observed with the serine protease inhibitor epsilon-amino-n-caproic acid (ACA). The deposited basement membrane-type of matrix reproducibly suppressed HDMEC proliferation and increased HDMEC adhesion to the substratum. These processes of matrix deposition and downregulation of endothelial cell proliferation, hallmarks of differentiating new capillaries in the end of angiogenesis, were recapitulated in our cell culture system by decreasing the matrix-degrading activity. These data suggest that our cell culture assay provides a simple and feasible model system for the study of capillary endothelial cell differentiation and vessel maturation in vitro.

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