PUBLICATION

IGF2 and IGF1R identified as novel tip cell genes in primary microvascular endothelial cell monolayers

Authors
Dallinga, M.G., Yetkin-Arik, B., Kayser, R.P., Vogels, I.M.C., Nowak-Sliwinska, P., Griffioen, A.W., van Noorden, C.J.F., Klaassen, I., Schlingemann, R.O.
ID
ZDB-PUB-191026-12
Date
2018
Source
Angiogenesis   21: 823-836 (Journal)
Registered Authors
Keywords
Angiogenesis, CD34, Cultured cells, Endothelial cells, Endothelial growth factors, IGF2, Tip cells
MeSH Terms
  • Humans
  • Receptor, TIE-1/genetics
  • Receptor, TIE-1/metabolism
  • Animals
  • Receptors, Somatomedin/genetics
  • Receptors, Somatomedin/metabolism*
  • Microvessels/cytology
  • Microvessels/metabolism*
  • Zebrafish
  • Chick Embryo
  • Gene Knockdown Techniques
  • Human Umbilical Vein Endothelial Cells/cytology
  • Human Umbilical Vein Endothelial Cells/metabolism*
  • Insulin-Like Growth Factor II/genetics
  • Insulin-Like Growth Factor II/metabolism*
  • Angiopoietin-2/genetics
  • Angiopoietin-2/metabolism
(all 17)
PubMed
29951828 Full text @ Angiogenesis
Abstract
Tip cells, the leading cells of angiogenic sprouts, were identified in cultures of human umbilical vein endothelial cells (HUVECs) by using CD34 as a marker. Here, we show that tip cells are also present in primary human microvascular endothelial cells (hMVECs), a more relevant endothelial cell type for angiogenesis. By means of flow cytometry, immunocytochemistry, and qPCR, it is shown that endothelial cell cultures contain a dynamic population of CD34+ cells with many hallmarks of tip cells, including filopodia-like extensions, elevated mRNA levels of known tip cell genes, and responsiveness to stimulation with VEGF and inhibition by DLL4. Furthermore, we demonstrate that our in vitro tip cell model can be exploited to investigate cellular and molecular mechanisms in tip cells and to discover novel targets for anti-angiogenesis therapy in patients. Small interfering RNA (siRNA) was used to knockdown gene expression of the known tip cell genes angiopoietin 2 (ANGPT2) and tyrosine kinase with immunoglobulin-like and EGF-like domains 1 (TIE1), which resulted in similar effects on tip cells and sprouting as compared to inhibition of tip cells in vivo. Finally, we identified two novel tip cell-specific genes in CD34+ tip cells in vitro: insulin-like growth factor 2 (IGF2) and IGF-1-receptor (IGF1R). Knockdown of these genes resulted in a significant decrease in the fraction of tip cells and in the extent of sprouting in vitro and in vivo. In conclusion, this study shows that by using our in vitro tip cell model, two novel essential tip cells genes are identified.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Allele Construct Type Affected Genomic Region
y7TgTransgenic Insertion
    1 - 1 of 1
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    Human Disease / Model
    No data available
    Sequence Targeting Reagents
    Target Reagent Reagent Type
    igf2aMO1-igf2aMRPHLNO
    igf2aMO2-igf2aMRPHLNO
    igf2bMO2-igf2bMRPHLNO
    igf2bMO3-igf2bMRPHLNO
    tp53MO4-tp53MRPHLNO
    1 - 5 of 5
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    Fish
    Antibodies
    No data available
    Orthology
    No data available
    Engineered Foreign Genes
    Marker Marker Type Name
    EGFPEFGEGFP
    1 - 1 of 1
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    Mapping