Time-lapse microscopy of macrophages during embryonic vascular development
Abstract
Background: Macrophages are present before the onset of blood flow, but very little is known about their function in vascular development. We have developed a technique to concurrently label both endothelial cells and macrophages for time-lapse microscopy using co-injection of fluorescently conjugated acetylated low-density lipoprotein (AcLDL) and phagocytic dye PKH26-PCL. Results: We characterize double-labeled cells to confirm specific labeling of macrophages. Double-labeled cells circulate, roll along the endothelium, and extravasate from vessels. Most observed macrophages are integrated into the vessel wall, showing an endothelial-like morphology. We used transgenic quail that express a fluorescent protein driven by the endothelial-specific promoter Tie1 in conjugation with the phagocytic dye to analyze these cells. Circulating PKH26-PCL-labeled cells are mostly Tie1−, but those which have integrated into the vessel wall are largely Tie1+. The endothelial-like phagocytic cells were generally stationary during normal vascular development. We, therefore, induced vascular remodeling and found that these cells could be recruited to sites of remodeling. Conclusions: The active interaction of endothelial cells and macrophages support the hypothesis that these cells are involved in vascular remodeling. The presence of phagocytic endothelial-like cells suggests either a myeloid-origin to certain endothelial cells or that circulating endothelial cells/hematopoietic stem cells have phagocytic capacity.
Additional Information
© 2012 Wiley Periodicals, Inc. Accepted 5 July 2012. Article first published online: 30 Jul. 2012. Grant sponsor: NSERC Discovery Program; Grant number: 342134; Grant sponsor: Canadian Foundation for Innovation; Grant sponsor: the Canada Research Chair Program. S.A.R. was supported by the Eugenie Lamothe Fellowship.Additional details
- Eprint ID
- 34514
- DOI
- 10.1002/dvdy.23835
- Resolver ID
- CaltechAUTHORS:20120927-130109788
- Eugenie Lamothe Fellowship
- 342134
- Natural Sciences and Engineering Research Council of Canada (NSERC)
- Canada Foundation for Innovation
- Canada Research Chair Program
- Created
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2012-09-27Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field