Cited by 479Angiogenesis and VEGF in CancerCell Adhesion Molecules ResearchLymphatic System and Diseases

Angiopoietin-2 differentially regulates angiogenesis through TIE2 and integrin signaling

Open access
Felcht, Moritz, Luck, Robert, Schering, Alexander, Seidel, Philipp, Srivastava, Kshitij, Hu, Junhao, Bartol, Arne, Kienast, Yvonne +14 more·2012·Journal of Clinical Investigation

Abstract

Angiopoietin-2 (ANG-2) is a key regulator of angiogenesis that exerts context-dependent effects on ECs. ANG-2 binds the endothelial-specific receptor tyrosine kinase 2 (TIE2) and acts as a negative regulator of ANG-1/TIE2 signaling during angiogenesis, thereby controlling the responsiveness of ECs to exogenous cytokines. Recent data from tumors indicate that under certain conditions ANG-2 can also promote angiogenesis. However, the molecular mechanisms of dual ANG-2 functions are poorly understood. Here, we identify a model for the opposing roles of ANG-2 in angiogenesis. We found that angiogenesis-activated endothelium harbored a subpopulation of TIE2-negative ECs (TIE2lo). TIE2 expression was downregulated in angiogenic ECs, which abundantly expressed several integrins. ANG-2 bound to these integrins in TIE2lo ECs, subsequently inducing, in a TIE2-independent manner, phosphorylation of the integrin adaptor protein FAK, resulting in RAC1 activation, migration, and sprouting angiogenesis. Correspondingly, in vivo ANG-2 blockade interfered with integrin signaling and inhibited FAK phosphorylation and sprouting angiogenesis of TIE2lo ECs. These data establish a contextual model whereby differential TIE2 and integrin expression, binding, and activation control the role of ANG-2 in angiogenesis. The results of this study have immediate translational implications for the therapeutic exploitation of angiopoietin signaling.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1172/jci58832

Cites

50 of 50 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • ANGPTs can signal via integrins to modulate vascular responses beyond the primary signaling mode through TIE2.

    “Recent studies have demonstrated that beyond the primary signaling mode through TIE2, ANGPTs can also signal via integrins to modulate vascular responses (13, 21–25).”
  • Integrins have been identified as alternative receptors for the angiopoietins in certain Tie2-negative non-endothelial cells and in endothelial tip cells of angiogenic vessel sprouts, which express low levels of Tie2.

    “Integrins, which regulate endothelial cell–cell and cell–matrix interactions, have been identified as alternative receptors for the angiopoietins in certain Tie2-negative non-endothelial cells22232425, and in the endothelial tip cells of angiogenic vessel sprouts, which express low levels of Tie2 (refs 26, 27).”
  • Our results differentiating between Ang1- and Ang2-mediated β1-integrin activation in the absence of Tie2 are in line with Ang2-integrin signalling in the endothelial tip cells, which express high Ang2 but low Tie2 levels.

    “Our results differentiating between Ang1- and Ang2-mediated β1-integrin activation in the absence of Tie2 are in line with Ang2-integrin signalling in the endothelial tip cells, which express high Ang2 but low Tie2 levels27.”

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. Imanishi Y, et al. Angiopoetin-2 stimulates breast cancer metastasis through the αvβ1 integrin-medi- ated pathway. Cancer Res. 2007;67(9):4254-4263.

Cited by

Sorted by citations

Authors
Felcht, M., Luck, R., Schering, A., Seidel, P., Srivastava, K., Hu, J., Bartol, A., Kienast, Y., Vettel, C., Loos, E. K., Kutschera, S., Bartels, S., Appak, S., Besemfelder, E., Terhardt, D., Chavakis, E., Wieland, T., Klein, C., Thomas, M., Uemura, A., Goerdt, S., & Augustin, H. G.
Affiliations
  • German Cancer Research Center (DE)
  • Heidelberg University (DE)
  • Goethe University Frankfurt (DE)
Corresponding author
Augustin, Hellmut G.
Venue
Journal of Clinical Investigation
Published
2012-06-01
Volume
122
Issue
6
Pages
1991-2005
ISSN
0021-9738 (ISSN-L)
OpenAlex
W2157985193
Cited by
479
References
50
Citations by year
2026: 20 · 2025: 33 · 2024: 28 · 2023: 44 · 2022: 29 · 2021: 21 · 2020: 31 · 2019: 36 · 2018: 37 · 2017: 40 · 2016: 40 · 2015: 37 · 2014: 41 · 2013: 30 · 2012: 12
FWCI
15.41
Type
journal article
Language
en
Open access
Locations
  • Journal of Clinical Investigation (publishedVersion)
  • Europe PMC (PubMed Central) (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • Deutsches Krebsforschungszentrum
  • Deutsche Forschungsgemeinschaft (Project B6, SFB873, SFB‐TR23)
  • Aventis Foundation
  • Japan Society for the Promotion of Science (22689046)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Angiogenesis and VEGF in Cancer
  • Health Sciences › Medicine › Immunology and Allergy › Cell Adhesion Molecules Research
  • Health Sciences › Medicine › Oncology › Lymphatic System and Diseases
Keywords
angiopoietin-2, angiogenesis, Tie2, integrin signaling, FAK phosphorylation, Rac1 activation, sprouting angiogenesis, endothelial cells, tumor angiogenesis
MeSH terms
Animals, Female, Humans, Male, Melanoma, Neoplasm Proteins, Neovascularization, Pathologic, Neuropeptides, Phosphorylation, Signal Transduction, Down-Regulation, Integrins, rac GTP-Binding Proteins, Receptor Protein-Tyrosine Kinases, rac1 GTP-Binding Protein, Angiopoietin-2, Endothelial Cells, Receptor, TIE-2, Mice, Focal Adhesion Kinase 1

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review