Inhibition of the VEGF receptor 2 combined with chronic hypoxia causes cell death‐dependent pulmonary endothelial cell proliferation and severe pulmonary hypertension

2001 ◽  
Vol 15 (2) ◽  
pp. 427-438 ◽  
Author(s):  
LAIMUTE TARASEVICIENE‐STEWART ◽  
YASUNORI KASAHARA ◽  
LORI ALGER ◽  
PETER HIRTH ◽  
GERALD MC MAHON ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
Pulmonary Hypertension ◽  
Endothelial Cell ◽  
Chronic Hypoxia ◽  
Endothelial Cell Proliferation ◽  
Vegf Receptor ◽  
Severe Pulmonary Hypertension

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.

scholarly journals Prenatal inflammation impairs intestinal microvascular development through a TNF-dependent mechanism and predisposes newborn mice to necrotizing enterocolitis

2019 ◽  
Vol 317 (1) ◽  
pp. G57-G66 ◽  
Author(s):  
Xiaocai Yan ◽  
Elizabeth Managlia ◽  
Xiao-Di Tan ◽  
Isabelle G. De Plaen
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cell ◽  
Necrotizing Enterocolitis ◽  
Endothelial Cell Proliferation ◽  
Vegf Receptor ◽  
Fetal Serum ◽  
Prenatal Inflammation ◽  
Vegfr2 Signaling

Prenatal inflammation is a risk factor for necrotizing enterocolitis (NEC), and it increases intestinal injury in a rat NEC model. We previously showed that maldevelopment of the intestinal microvasculature and lack of vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) signaling play a role in experimental NEC. However, whether prenatal inflammation affects the intestinal microvasculature remains unknown. In this study, mouse dams were injected intraperitoneally with lipopolysaccharide (LPS) or saline at embryonic day 17. Neonatal intestinal microvasculature density, endothelial cell proliferation, and intestinal VEGF-A and VEGFR2 proteins were assessed in vivo. Maternal and fetal serum TNF concentrations were measured by ELISA. The impact of TNF on the neonatal intestinal microvasculature was examined in vitro and in vivo, and we determined whether prenatal LPS injection exacerbates experimental NEC via TNF. Here we found that prenatal LPS injection significantly decreased intestinal microvascular density, endothelial cell proliferation, and VEGF and VEGFR2 protein expression in neonatal mice. Prenatal LPS injection increased maternal and fetal serum levels of TNF. TNF decreased VEGFR2 protein in vitro in neonatal endothelial cells. Postnatal TNF administration in vivo decreased intestinal microvasculature density, endothelial cell proliferation, and VEGF and VEGFR2 protein expression and increased the incidence of severe NEC. These effects were ameliorated by stabilizing hypoxia-inducible factor-1α, the master regulator of VEGF. Furthermore, prenatal LPS injection significantly increased the incidence of severe NEC in our model, and the effect was dependent on endogenous TNF. Our study suggests that prenatal inflammation increases the susceptibility to NEC, downregulates intestinal VEGFR2 signaling, and affects perinatal intestinal microvascular development via a TNF mechanism. NEW & NOTEWORTHY This report provides new evidence that maternal inflammation decreases neonatal intestinal VEGF receptor 2 signaling and endothelial cell proliferation, impairs intestinal microvascular development, and predisposes neonatal mouse pups to necrotizing enterocolitis (NEC) through inflammatory cytokines such as TNF. Our data suggest that alteration of intestinal microvascular development may be a key mechanism by which premature infants exposed to prenatal inflammation are at risk for NEC and preserving the VEGF/VEGF receptor 2 signaling pathway may help prevent NEC development.

Abstract P248: Novel Role of Axl Kinase in Endothelial Cell Proliferation and Pulmonary Arterial Hypertension

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Anastasia Gorelova ◽  
Sanghamitra Sahoo ◽  
Patrick J Pagano
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cell ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Endothelial Cell Proliferation ◽  
Vegf Receptor ◽  
Drug Bioavailability ◽  
Endothelial Proliferation ◽  
Pulmonary Arterial

Pulmonary arterial hypertension (PAH) is a poorly characterized disease of unclear etiology that affects individuals of all ages. Vascular remodeling and increase in pulmonary artery (PA) and right ventricle (RV) pressures are two major culprits in RV failure and death in PAH. Recent advances in the study of PAH suggest that endothelial cell proliferation is an early instigator of this hallmark remodeling. We postulated that Axl receptor tyrosine kinase (implicated in pro-proliferative and pro-survival signaling in cancerous cells) could mediate endothelial proliferation and thus hemodynamic changes occurring in PAH. Using immunofluorescent microscopy of lung microvessels of human PAH vs. non-PAH, we observed Axl expression on intimal endothelial cells but not medial smooth muscle cells. Furthermore, digitized microscopy revealed that Axl tended to increase on the endothelium of PAH vessels (1.65±0.15-fold vs. non-PAH; n=3-4; p=0.057 ). To address the role of Axl in vivo , an Axl inhibitor R428 was employed in a mouse model of pulmonary hypertension. C57Bl/6 mice were subjected to hypoxia at pO 2 =10% and VEGF receptor antagonist SU5416 (Su/Ch) or normoxia (Norm) for 3 wks. Indeed, Su/Ch caused a significant rise in lung Axl protein and mRNA (7.1±0.4- and 2.4±0.5-fold, Su/Ch vs. Norm, protein and mRNA, respectively; n=3-6; p<0.01). As predicted, RV pressure (RVP) rose from 27±0.5 to 43±1.8 mmHg (Norm vs. Su/Ch; n=6; p<0.01). However, we did not observe a decrease in RVP with twice-daily gavage of 75 mg/kg R428 (43±1.4 mmHg, Su/Ch + R428; n=6). A similar pattern was observed with mean PA pressure (18.4±0.3 and 28.7±1.2 mmHg, Norm vs. Su/Ch, p<0.01; 28.7±0.9 mmHg, Su/Ch + R428), RV resistance (1403±256 vs. 2703±464 Wood units, Norm vs. Su/Ch, n/s; vs. 3610±625 Wood units, Su/Ch + R428) and Fulton index (0.26±0.01 and 0.34±0.02, Norm vs. Su/Ch, p<0.05; 0.38±0.02, Su/Ch + R428). In conclusion, our preliminary results demonstrate upregulated Axl expression in the endothelium of PAH patients and in lungs of PH mice and suggest that Axl kinase may play a novel role in pulmonary vascular endothelial proliferation and remodeling in PAH. It remains to be determined whether drug bioavailability or severity of disease precluded an ameliorative effect of an Axl inhibitor.

Hypoxia induces different genes in the lungs of rats compared with mice

2003 ◽  
Vol 12 (3) ◽  
pp. 209-219 ◽  
Author(s):  
Yasushi Hoshikawa ◽  
Patrick Nana-Sinkam ◽  
Mark D. Moore ◽  
Sylk Sotto-Santiago ◽  
Tzulip Phang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Proliferation ◽  
Endothelial Cell ◽  
Vascular Remodeling ◽  
Chronic Hypoxia ◽  
Gene Expression Pattern ◽  
Endothelial Cell Proliferation ◽  
Pulmonary Vascular Remodeling ◽  
Hypoxic Conditions ◽  
Expression Of Genes

Different animal species have a varying response to hypoxia. Mice develop less pulmonary artery thickening after chronic hypoxia exposure than rats. We hypothesized that the lung tissue gene expression pattern displayed in hypoxic rats would differ from that of hypoxic mice. We exposed Sprague-Dawley rats and C57BL/6 mice to both 1 and 3 wk of hypobaric hypoxia. Although both species developed pulmonary hypertension, mice showed less pulmonary vascular remodeling than rats. Microarray gene analysis demonstrated a distinct pattern of gene expression between mice and rats when exposed to hypoxic conditions. In addition, some genes appeared to be more responsive at an earlier time point of 1 wk of hypoxia. Hypoxic conditions in the rat induce genes involved in endothelial cell proliferation, repression of apoptosis, and vasodilation. Mice exposed to hypoxic conditions decrease the expression of genes involved in vasodilation and in endothelial cell proliferation. Although we cannot determine whether the differential expression of genes during chronic hypoxia is cause or consequence of the differential pulmonary vascular remodeling, we propose that a balance between over- and under-expression of a selective group of genes may be responsible for lung vascular remodeling and vascular tone control.

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
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