Related Experiment Videos
Angiopoietin affects neutrophil migration
Daniel H Sturn1, Clemens Feistritzer, Birgit A Mosheimer
1Division of General Internal Medicine, Department of Internal Medicine, Medical University of Innsbruck, Innsbruck, Austria.
Microcirculation (New York, N.Y. : 1994)
|July 16, 2005
Summary
Angiopoietin-1 and angiopoietin-2 influence neutrophil migration via the Tie-2 receptor. These angiogenic factors modulate inflammation by affecting neutrophil movement and inhibiting VEGF-directed chemotaxis.
Area of Science:
- Immunology
- Molecular Biology
- Vascular Biology
Background:
- Vascular growth factors regulate leukocyte infiltration post-ischemia.
- Angiopoietins are key angiogenic factors with incompletely understood roles in inflammation.
Purpose of the Study:
- To investigate the effects of angiopoietin-1 and angiopoietin-2 on human neutrophils.
- To determine the involvement of the angiopoietin receptor Tie-2 in these interactions.
Main Methods:
- Human neutrophils isolated from venous blood.
- Micropore filter assays for cell migration.
- Reverse transcriptase-polymerase chain reaction (RT-PCR) and Fluorescence-Activated Cell Sorting (FACS) for receptor expression analysis.
- Functional assays using signaling enzyme blockers.
Main Results:
- Angiopoietins demonstrated chemotactic activity for neutrophils.
- Angiopoietins exhibited antagonistic effects on each other and inhibited VEGF-directed neutrophil migration.
- All observed angiopoietin effects were dependent on the Tie-2 receptor, which is expressed on neutrophils (mRNA and protein levels).
Conclusions:
- Human neutrophils express the Tie-2 receptor.
- Ligand binding to Tie-2 by angiopoietin-1 or angiopoietin-2 influences neutrophil migration and inhibits VEGF-mediated chemotaxis.
- Angiopoietins play a significant role in modulating neutrophilic inflammation.