Title

3D model of angiogenesis as a platform for analysis of endothelial cell derived microvesicles

ORCiD

Dr. Benjamin D. Zeitlin: 0000-0003-0110-0188

Document Type

Conference Presentation

Conference Title

International Society for Extracellular Vesicles

Location

Gothenburg, Swededn

Conference Dates

April 18-21, 2012

Date of Presentation

4-18-2012

Abstract

The aim of this study was to determine the utility of an in vitro 3D model of endothelial cell (EC) angiogenic sprouting for the microscopic study of EC microvesicle (MV) release and cellular interaction. Few protocols allow simple observation of cell interaction with MVs in vitro. For those that do, the focus is primarily on cellular response to MVs from other cell types. ECs are well known to release both MVs and exosomes when activated. Also, non–EC-derived extracellular vesicles may stimulate angiogenesis but less is known of the action of EC-derived MVs on other ECs. Herein, ECs were encapsulated in solid droplets of a peptide matrix. ECs formed networks in the droplets prior to embedding in collagen. Proangiogenic mediators induced planar cell invasion and growth of capillary-like sprouts. MV release and cellular interaction were observed microscopically using either differential interference contrast (DIC), Nikon advanced modulation contrast (NAMC), normal or confocal fluorescence. The EC release and uptake of MVs, estimated to be ∼1 µm in diameter, were readily observable by eye using the 3D planar model with either DIC or NAMC. Actin probes clearly defined vesicles by confocal fluorescence, yet more variable results were obtained by fluorescent microscopy with probes to EC markers. This planar 3D in vitro model of angiogenesis is a useful tool for investigating the interaction of ECs with MVs around 1 µm in diameter. It also allows for fluorescent labeling for specific markers of both cells and MVs of ∼1 µm or potentially smaller.