Abstract 531: Tie-2/Cre--Mediated Conditional Deletion of Lipid Phosphate Phosphatase-3 Reveals Its Role in Endothelial Cell Apoptosis

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Ishita Chatterjee ◽  
Kishore K Wary

Rationale: A recent genome-wide association study (GWAS) has linked a frequently occurring variation in the LPP3 (also known as PPAP2b) loci to increased risk of coronary heart disease (CAD). However, the in vivo function of LPP3 in vascular endothelial cell is incompletely understood. Goal: To address the endothelial cell (EC) specific function of Lpp3 in mice. Results: Tie-2/Cre mediated Lpp3 deletion did not affect normal vasculogenesis in early embryonic development, in contrast, in late embryonic stages it led to impaired angiogenesis associated with hemorrhage, edema and late embryonic lethal phenotype. Immunohistochemical staining followed by microscopic analyses of mutant embryos revealed reduced fibronectin and VE-cadherin expression throughout different vascular bed, and increased apoptosis in CD31+ vascular structures. Transmission electron microscopy (TEM) showed the presence of apoptotic endothelial cells and disruption of adherens junctions in mutant embryos. LPP3-knockdown in vitro showed an increase in p53 and p21 protein levels, with concomitant decrease in cell proliferation. LPP3-knockdown also decreased transendothelial electrical resistance (TER), interestingly re-expression of ß-catenin cDNA into LPP3-depleted endothelial cells partially restored the effect of loss of LPP3. Conclusion: These results suggest the ability of LPP3 to regulate survival and apoptotic activities of endothelial cells during patho/physiological angiogenesis.

Blood ◽  
2010 ◽  
Vol 115 (20) ◽  
pp. 4130-4137 ◽  
Author(s):  
Jinmin Gao ◽  
Lei Sun ◽  
Lihong Huo ◽  
Min Liu ◽  
Dengwen Li ◽  
...  

Cylindromatosis (CYLD) is a deubiquitinase that was initially identified as a tumor suppressor and has recently been implicated in diverse normal physiologic processes. In this study, we have investigated the involvement of CYLD in angiogenesis, the formation of new blood vessels from preexisting ones. We find that knockdown of CYLD expression significantly impairs angiogenesis in vitro in both matrigel-based tube formation assay and collagen-based 3-dimensional capillary sprouting assay. Disruption of CYLD also remarkably inhibits angiogenic response in vivo, as evidenced by diminished blood vessel growth into the angioreactors implanted in mice. Mechanistic studies show that CYLD regulates angiogenesis by mediating the spreading and migration of vascular endothelial cells. Silencing of CYLD dramatically decreases microtubule dynamics in endothelial cells and inhibits endothelial cell migration by blocking the polarization process. Furthermore, we identify Rac1 activation as an important factor contributing to the action of CYLD in regulating endothelial cell migration and angiogenesis. Our findings thus uncover a previously unrecognized role for CYLD in the angiogenic process and provide a novel mechanism for Rac1 activation during endothelial cell migration and angiogenesis.


2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Jiping Cai ◽  
Ruili Wei ◽  
Jinwei Cheng

Vascular endothelial cell growth inhibitor (VEGI) is a recently identified antiangiogenic cytokine that belongs to the TNF superfamily, and could effectively inhibit endothelial cell proliferation and angiogenesis. Synthetic peptide CTT (CTTHWGFTLC) has been found to suppress invasion and migration of both tumor and endothelial cells by potent and selective inhibition of MMP-2 and MMP-9. To prepare chimeric protein VEGI-CTT for more potent antitumor therapy, the recombinant expression vector pET-VEGI-CTT was constructed. This fusion protein was expressed in inclusion bodies inE. coliBL21 (DE3), and was refolded and purified by immobilized metal affinity chromatography using His-tag. Purified VEGI-CTT protein was characterized by proliferation assays of the endothelial cells and casein degradation assay in vitro. The results demonstrated that chimeric protein VEGI-CTT had a potent activity of antiangiogenesis through inhibiting the proliferation of endothelial cells, and could effectively reduce the activity of MMP-2 and MMP-9. The preliminarily in vivo study demonstrated that chimeric protein VEGI-CTT had more potent antitumor activity than VEGI and/or CTT peptide against CA46 human lymphoma xenografts in nude mice. Thus, these facts that are derived from the present study suggest that the chimeric protein VEGI-CTT may be used for tumor therapy in the future.


Development ◽  
1995 ◽  
Vol 121 (4) ◽  
pp. 1089-1098 ◽  
Author(s):  
T.M. Schlaeger ◽  
Y. Qin ◽  
Y. Fujiwara ◽  
J. Magram ◽  
T.N. Sato

Vascular endothelial cells play essential roles in the function and development of the cardiovascular system. However, due to the lack of lineage-specific markers suitable for molecular and biochemical analyses, very little is known about the molecular mechanisms that regulate endothelial cell differentiation. We report the first vascular endothelial cell lineage-specific (including angioblastic precursor cells) 1.2 kb promoter in transgenic mice. Moreover, deletion analysis of this promoter region in transgenic embryos revealed multiple elements that are required for the maximum endothelial cell lineage-specific expression. This is a powerful molecular tool that will enable us to identify factors and cellular signals essential for the establishment of vascular endothelial cell lineage. It will also allow us to deliver genes specifically into this cell type in vivo to test specifically molecules that have been implicated in cardiovascular development. Furthermore, we have established embryonic stem (ES) cells from the blastocysts of the transgenic mouse that carry the 1.2 kb promoter-LacZ reporter transgene. These ES cells were able to differentiate in vitro to form cystic embryoid bodies (CEB) that contain endothelial cells determined by PECAM immunohistochemistry. However, these in vitro differentiated endothelial cells did not express the LacZ reporter gene. This indicates the lack of factors and/or cellular interactions which are required to induce the expression of the reporter gene mediated by this 1.2 kb promoter in this in vitro differentiation system. Thus this system will allow us to screen for the putative inducers that exist in vivo but not in vitro. These putative inducers are presumably important for in vivo differentiation of vascular endothelial cells.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Ha-Rim Seo ◽  
Hyo Eun Jeong ◽  
Hyung Joon Joo ◽  
Seung-Cheol Choi ◽  
Jong-Ho Kim ◽  
...  

Background: Human body contains many kinds of different type of endothelial cells (EC). However, cellular difference of their angiogenic potential has been hardly understood. We compared in vitro angiogenic potential between arterial EC and venous EC and investigated its underlying molecular mechanisms. Method: Used human aortic endothelial cells (HAEC) which was indicated from arterial EC and human umbilical vein endothelial cells (HUVEC) indicated from venous EC. To explore angiogenic potential in detail, we adopted a novel 3D microfluidic angiogenesis assay system, which closely mimic in vivo angiogenesis. Results: In 3D microfluidic angiogenesis assay system, HAEC demonstrated stronger angiogenic potential compared to HUVEC. HAEC maintained its profound angiogenic property under different biophysical conditions. In mRNA microarray sorted on up- regulated or down-regulated genes, HAEC demonstrated significantly higher expression of gastrulation brain homeobox 2 (GBX2), fibroblast grow factor 2 (FGF2), FGF5 and collagen 8a1. Angiogenesis-related protein assay revealed that HAEC has higher secretion of endogenous FGF2 than HUVEC. HAEC has only up-regulated FGF2 and FGF5 in this part of FGF family. Furthermore, FGF5 expression under vascular endothelial growth factor-A (VEGF-A) stimulation was higher in HAEC compared to HUVEC although VEGF-A augmented FGF5 expression in both HAEC and HUVEC. Those data suggested that FGF5 expression in both HAEC and HUVEC is partially dependent to VEGF-A stimulate. HUVEC and HAEC reduced vascular density after FGF2 and FGF5 siRNA treat. Conclusion: HAEC has stronger angiogenic potential than HUVEC through up-regulation of endogenous FGF2 and FGF5 expression


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.


2000 ◽  
Vol 113 (1) ◽  
pp. 59-69 ◽  
Author(s):  
M.F. Carlevaro ◽  
S. Cermelli ◽  
R. Cancedda ◽  
F. Descalzi Cancedda

Vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) induces endothelial cell migration and proliferation in culture and is strongly angiogenic in vivo. VEGF synthesis has been shown to occur in both normal and transformed cells. The receptors for the factor have been shown to be localized mainly in endothelial cells, however, the presence of VEGF synthesis and the VEGF receptor in cells other than endothelial cells has been demonstrated. Neoangiogenesis in cartilage growth plate plays a fundamental role in endochondral ossification. We have shown that, in an avian in vitro system for chondrocyte differentiation, VEGF was produced and localized in cell clusters totally resembling in vivo cartilage. The factor was synthesized by hypertrophic chondrocytes and was released into their conditioned medium, which is highly chemotactic for endothelial cells. Antibodies against VEGF inhibited endothelial cell migration induced by chondrocyte conditioned media. Similarly, endothelial cell migration was inhibited also by antibodies directed against the VEGF receptor 2/Flk1 (VEGFR2). In avian and mammalian embryo long bones, immediately before vascular invasion, VEGF was distinctly localized in growth plate hypertrophic chondrocytes. In contrast, VEGF was not observed in quiescent and proliferating chondrocytes earlier in development. VEGF receptor 2 colocalized with the factor both in hypertrophic cartilage in vivo and hypertrophic cartilage engineered in vitro, suggesting an autocrine loop in chondrocytes at the time of their maturation to hypertrophic cells and of cartilage erosion. Regardless of cell exposure to exogenous VEGF, VEGFR-2 phosphorylation was recognized in cultured hypertrophic chondrocytes, supporting the idea of an autocrine functional activation of signal transduction in this non-endothelial cell type as a consequence of the endogenous VEGF production. In summary we propose that VEGF is actively responsible for hypertrophic cartilage neovascularization through a paracrine release by chondrocytes, with invading endothelial cells as a target. Furthermore, VEGF receptor localization and signal transduction in chondrocytes strongly support the hypothesis of a VEGF autocrine activity also in morphogenesis and differentiation of a mesoderm derived cell.


2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Junyao Yang ◽  
Wen Wang ◽  
Qian Wang ◽  
Lingfang Zeng

Background: Histone deacetylase 7 (HDAC7) belongs to class II HDAC family, playing a pivotal role in the maintenance of endothelium integrity. There are 8 splicing variants in mouse HDAC7 mRNAs. Within the 5’ terminal non-coding area of some variants, there exist some short open reading frames (sORFs). Whether these sORFs can be translated and their potential roles in cellular physiology remain unclear. Method and results: Our previous studies suggested that one mouse HDAC7 produced a 7aa peptide from the non-coding area. In this study, we demonstrated that one sORF encoding a 7 amino acids (aa)-peptide could be translated in response to vascular endothelial cell growth factor (VEGF) in vascular progenitor cells (VPCs). The 7aa-peptide (7A) could be phosphorylated at serine residue via MEKK1. Importantly, the phosphorylated 7aa-peptide (7Ap) could transfer the phosphorylation group to the Thr residue of the 14-3-3γ protein in a cell free in-gel buffer system. The in vitro functional analyses revealed that 7A enhanced VEGF-induced VPC migration and differentiation toward endothelial cell (EC) lineage, in which MEKK1 and 14-3-3γ served as upstream kinase and downstream effector respectively. Knockdown of either MEKK1 or 14-3-3γ attenuated VEGF-induced VPC migration and differentiation. Exogenous 7Ap could rescue VEGF effect in MEKK1 but not in 14-3-3γ knockdown cells. The in vivo studies showed that 7A especially 7Ap induced capillary vessel formation within matrigel plug assays, increased re-endothelialization and suppressed neointima formation in the femoral artery injury model, and promoted the foot blood perfusion recovery in the hindlimb ischemia model. Conclusion: These results indicate that the sORFs within the non-coding area can be translated under some circumstances and that the 7aa-peptide may play an important role in cellular processes like migration and differentiation via acting as a phosphorylation carrier. Significance: As a phosphorylation carrier, 7aa possesses therapeutic potentials in tackling angiogenesis related diseases.


Vaccines ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 70 ◽  
Author(s):  
Gerna ◽  
Kabanova ◽  
Lilleri

In the 1970s–1980s, a striking increase in the number of disseminated human cytomegalovirus (HCMV) infections occurred in immunosuppressed patient populations. Autopsy findings documented the in vivo disseminated infection (besides fibroblasts) of epithelial cells, endothelial cells, and polymorphonuclear leukocytes. As a result, multiple diagnostic assays, such as quantification of HCMV antigenemia (pp65), viremia (infectious virus), and DNAemia (HCMV DNA) in patient blood, were developed. In vitro experiments showed that only low passage or endothelial cell-passaged clinical isolates, and not laboratory-adapted strains, could reproduce both HCMV leuko- and endothelial cell-tropism, which were found through genetic analysis to require the three viral genes UL128, UL130, and UL131 of the HCMV UL128 locus (UL128L). Products of this locus, together with gH/gL, were shown to form the gH/gL/pUL128L pentamer complex (PC) required for infection of epithelial cells/endothelial cells, whereas gH/gL and gO form the gH/gL/gO trimer complex (TC) required for infection of all cell types. In 2016, following previous work, a receptor for the TC that mediates entry into fibroblasts was identified as PDGFRα, while in 2018, a receptor for the PC that mediates entry into endothelial/epithelial cells was identified as neuropilin2 (Nrp2). Furthermore, the olfactory receptor family member OR14I1 was recently identified as a possible additional receptor for the PC in epithelial cells. Thus, current data support two models of viral entry: (i) in fibroblasts, following interaction of PDGFRα with TC, the latter activates gB to fuse the virus envelope with the cell membrane, whereas (ii) in epithelial cells/endothelial cells, interaction of Nrp2 (and OR14I1) with PC promotes endocytosis of virus particles, followed by gB activation by gH/gL/gO (or gH/gL) and final low-pH entry into the cell.


2016 ◽  
Vol 231 (1) ◽  
pp. 97-108 ◽  
Author(s):  
Mahendra Prasad Bhatt ◽  
Yeon-Ju Lee ◽  
Se-Hui Jung ◽  
Yong Ho Kim ◽  
Jong Yun Hwang ◽  
...  

C-peptide exerts protective effects against diabetic complications; however, its role in inhibiting hyperglycemic memory (HGM) has not been elucidated. We investigated the beneficial effect of C-peptide on HGM-induced vascular damage in vitro and in vivo using human umbilical vein endothelial cells and diabetic mice. HGM induced apoptosis by persistent generation of intracellular ROS and sustained formation of ONOO− and nitrotyrosine. These HGM-induced intracellular events were normalized by treatment with C-peptide, but not insulin, in endothelial cells. C-peptide also inhibited persistent upregulation of p53 and activation of mitochondrial adaptor p66shc after glucose normalization. Further, C-peptide replacement therapy prevented persistent generation of ROS and ONOO− in the aorta of diabetic mice whose glucose levels were normalized by the administration of insulin. C-peptide, but not insulin, also prevented HGM-induced endothelial apoptosis in the murine diabetic aorta. This study highlights a promising role for C-peptide in preventing HGM-induced intracellular events and diabetic vascular damage.


Blood ◽  
2011 ◽  
Vol 118 (6) ◽  
pp. 1699-1709 ◽  
Author(s):  
Isabelle Ligi ◽  
Stéphanie Simoncini ◽  
Edwige Tellier ◽  
Paula Frizera Vassallo ◽  
Florence Sabatier ◽  
...  

Abstract Low birth weight (LBW) is associated with increased risk of cardiovascular diseases at adulthood. Nevertheless, the impact of LBW on the endothelium is not clearly established. We investigate whether LBW alters the angiogenic properties of cord blood endothelial colony forming cells (LBW-ECFCs) in 25 preterm neonates compared with 25 term neonates (CT-ECFCs). We observed that LBW decreased the number of colonies formed by ECFCs and delayed the time of appearance of their clonal progeny. LBW dramatically reduced LBW-ECFC capacity to form sprouts and tubes, to migrate and to proliferate in vitro. The angiogenic defect of LBW-ECFCs was confirmed in vivo by their inability to form robust capillary networks in Matrigel plugs injected in nu/nu mice. Gene profile analysis of LBW-ECFCs demonstrated an increased expression of antiangiogenic genes. Among them, thrombospondin 1 (THBS1) was highly expressed at RNA and protein levels in LBW-ECFCs. Silencing THBS1 restored the angiogenic properties of LBW-ECFCs by increasing AKT phosphorylation. The imbalance toward an angiostatic state provide a mechanistic link between LBW and the impaired angiogenic properties of ECFCs and allows the identification of THBS1 as a novel player in LBW-ECFC defect, opening new perspectives for novel deprogramming agents.


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