scholarly journals Erratum for: Roundabout4 Suppresses Glioma-Induced Endothelial Cell Proliferation, Migration and Tube Formation in Vitro by Inhibiting VEGR2-Mediated PI3K/AKT and FAK Signaling Pathways

2021 ◽  
Vol 55 (5) ◽  
pp. 652-653

2015 ◽  
Vol 35 (5) ◽  
pp. 1689-1705 ◽  
Author(s):  
Heng Cai ◽  
Yixue Xue ◽  
Zhen Li ◽  
Yi Hu ◽  
Zhenhua Wang ◽  
...  

Background and Aims: Endothelial cell (EC) proliferation, migration, and tube formation are the critical steps for tumor angiogenesis, which is involved in the formation of new tumor blood vessels. Roundabout4 (Robo4), a new member of Robo proteins family, is specifically expressed in endothelial cells. This study aimed to investigate the effects of Robo4 on glioma-induced endothelial cell proliferation, migration and tube formation in vitro. Methods and Results: We found that Robo4 was endogenously expressed in Human Brain Microvascular Endothelial Cells (HBMECs), while Robo4 was significantly down-regulated in endothelial cells cultured in glioma conditioned medium. Robo4 over-expression remarkably suppressed glioma-induced endothelial cell proliferation, migration and tube formation in vitro. In addition, Robo4 influenced the glioma-induced angiogenesis via binding to its ligand Slit2. Further studies demonstrated that the knockdown of Robo4 up-regulated the phosphorylation of VEGFR2, PI3K, AKT and FAK in EC cultured in glioma conditioned medium. VEGFR2 inhibitor SU-1498, AKT inhibitor LY294002 and FAK inhibitor 14 (FAK inhibitor) blocked the Robo4 knockdown-mediated alteration in glioma angiogenesis in vitro. Conclusion: Our results proved that Robo4 suppressed glioma-induced endothelial cell proliferation, migration and tube formation in vitro by inhibiting VEGR2-mediated activation of PI3K/AKT and FAK signaling pathways.



Endocrinology ◽  
2011 ◽  
Vol 152 (7) ◽  
pp. 2845-2856 ◽  
Author(s):  
Jacqueline A. Maybin ◽  
Sharon Battersby ◽  
Nikhil Hirani ◽  
Leonid L. Nikitenko ◽  
Hilary O. D. Critchley ◽  
...  

After menstruation, the endometrium has a remarkable capacity for repair, but the factors involved remain undefined. We hypothesize adrenomedullin (AM) plays a role in this process. Premenstrually progesterone levels decline, stimulating prostaglandin (PG) synthesis, vasoconstriction, and hypoxia. This study aimed to determine 1) AM expression throughout the menstrual (M) cycle and 2) its regulation by PG and hypoxia. Human endometrial biopsies (n = 51) were collected with ethical approval and consent. AM mRNA expression was examined by quantitative RT-PCR and was found to be selectively elevated in endometrium from the menstrual (M) phase (P < 0.001). AM immunohistochemical staining was maximal in M and proliferative (P) endometrium. Culture of secretory, but not P, explants with 100 nm PGF2α or hypoxia (0.5% O2) increased AM mRNA (P < 0.05). P explants were induced to increase AM expression using in vitro progesterone withdrawal but required the presence of hypoxia (P < 0.05). Short hairpin sequences against hypoxia-inducible factor-1α (HIF-1α) inhibited AM hypoxic up-regulation but did not alter PGF2α-induced expression. The AM receptor was immunolocalized to endothelial cells in both lymphatic and blood vessels. Conditioned medium from PGF2α-treated cells increased endothelial cell proliferation and branching (P < 0.05). This was abolished by AM receptor antagonists. In conclusion, AM is elevated at the time of endometrial repair and induces both angiogenesis and lymphangiogenesis by stimulating endothelial cell proliferation and tube formation. In the human endometrium, AM expression is up-regulated by two mechanisms: a HIF-1α-mediated hypoxic induction and a HIF-1α-independent PGF2α pathway. These physiological mechanisms may provide novel therapeutic targets for disorders such as heavy menstrual bleeding.



2007 ◽  
Vol 252 (2) ◽  
pp. 235-243 ◽  
Author(s):  
Mok-Ryeon Ahn ◽  
Kazuhiro Kunimasa ◽  
Toshiro Ohta ◽  
Shigenori Kumazawa ◽  
Miya Kamihira ◽  
...  


2004 ◽  
Vol 287 (5) ◽  
pp. H2099-H2105 ◽  
Author(s):  
Dahai Wang ◽  
Oscar A. Carretero ◽  
Xiao-Yi Yang ◽  
Nour-Eddine Rhaleb ◽  
Yun-He Liu ◽  
...  

N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP), a natural inhibitor of pluripotent hematopoietic stem cell proliferation, has been suggested as capable of promoting an angiogenic response. We studied whether Ac-SDKP stimulates endothelial cell proliferation, migration, and tube formation; enhances angiogenic response in the rat cornea after implantation of a tumor spheroid; and increases capillary density in rat hearts with myocardial infarction (MI). In vitro, an immortal BALB/c mouse aortic endothelial 22106 cell line was used to determine the effects of Ac-SDKP on endothelial cell proliferation and migration and tube formation. In vivo, a 9L-gliosarcoma cell spheroid (250–300 μm in diameter) was implanted in the rat cornea and vehicle or Ac-SDKP (800 μg·kg−1·day−1ip) infused via osmotic minipump. Myocardial capillary density was studied in rats with MI given either vehicle or Ac-SDKP. We found that Ac-SDKP 1) stimulated endothelial cell proliferation and migration and tube formation in a dose-dependent manner, 2) enhanced corneal neovascularization, and 3) increased myocardial capillary density. Endothelial cell proliferation and angiogenesis stimulated by Ac-SDKP could be beneficial in cardiovascular diseases such as hypertension and MI. Furthermore, because Ac-SDKP is mainly cleaved by ACE, it may partially mediate the cardioprotective effect of ACE inhibitors.



1999 ◽  
Vol 112 (10) ◽  
pp. 1599-1609 ◽  
Author(s):  
B.M. Kraling ◽  
D.G. Wiederschain ◽  
T. Boehm ◽  
M. Rehn ◽  
J.B. Mulliken ◽  
...  

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.



2010 ◽  
Vol 628 (1-3) ◽  
pp. 42-50 ◽  
Author(s):  
Xu Dai ◽  
Hong-jin Song ◽  
Shi-gang Cui ◽  
Ting Wang ◽  
Qian Liu ◽  
...  


Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 706-707
Author(s):  
Robert Q Miao ◽  
Jun Agata ◽  
Lee Chao ◽  
Julie Chao

P76 Kallistatin is a serine proteinase inhibitor (serpin) which has multifunctions including regulation of tissue kallikrein activity, blood pressure, inflammation and neointima hyperplasia. In this study, we investigated the potential role of kallistatin in vascular biology by studying its effects on the proliferation, migration and adhesion of cultured primary human endothelial cells in vitro, and angiogenesis in the ischemic hindlimb of rats. Purified kallistatin significantly inhibits cultured endothelial cell proliferation, migration and adhesion induced by VEGF or bFGF. To further investigate the role of kallistatin in vascular growth in vivo, we prepared adenovirus carrying the human kallistatin gene under the control of the cytomegalovirus promoter/enhancer (Ad.CMV-cHKBP). Expression of recombinant human kallistatin in HEK 293 cells transfected with Ad.CMV-cHKBP was identified by a specific ELISA. The effect of adenovirus-mediated kallistatin gene delivery on angiogenesis was evaluated in a rat model of hindlimb ischemia. Adenovirus carrying the human kallistatin or green fluorescent protein (GFP) gene were injected locally into the ischemic adductor at the time of surgery. Histological and morphometric analysis at 14 days post injection showed that adenovirus-mediated kallistatin gene delivery significantly reduced capillary density in the ischemic muscle as compared to that of control rats injected with GFP. The anti-angiogenic effect of kallistatin was associated with reduced regional blood flow in the ischemic hindlimb measured by microsphere assays. Expression of human kallistatin was identified in the injected muscle and immunoreactive human kallistatin levels were measured in the muscle and in the circulation of rats following kallistatin gene delivery. These results demonstrate a novel role of kallistatin in the inhibition of angiogenesis and in vascular remodeling.



2019 ◽  
Vol 317 (1) ◽  
pp. G57-G66 ◽  
Author(s):  
Xiaocai Yan ◽  
Elizabeth Managlia ◽  
Xiao-Di Tan ◽  
Isabelle G. De Plaen

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.



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