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Updated: Sep 8, 2025
Acute Brain Trauma in Mice Followed By Longitudinal Two-photon Imaging
Published on: April 6, 2014
Microglia express Tie2 in a longitudinal imaging study of acute neural injury in mice
Jennifer Brodsky1, Zeinab Tashi1, Sharon K Christopher2
1School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ 85287.
Abstract:
The Tie2 receptor tyrosine kinase is expressed both in stroke recovery and cancer progression by vascular endothelial and myeloid lineage cells. Tie2 mechanisms have been described in vascular maturation, but the receptor's immune role remains poorly understood. Here, we describe the expression of Tie2 in microglia in response to an acute neural injury, uncovering a potential new role for these cells. Using magnetic resonance imaging (MRI) and the Ts-Biotag multimodal reporter mouse, we noninvasively imaged Tie2 expression dynamics in a longitudinal study of neural injury to identify key timepoints in wound signaling and healing. Using labeled bone marrow chimeras, we further determined that Tie2 is expressed in brain-resident microglia but not invading macrophages. Our results establish the utility of noninvasive molecular imaging for longitudinal studies of neuroimmune function and present a new role for Tie2 as a uniquely expressed marker of microglial function during wound healing.
Insights
Researchers found the Tie2 receptor in microglia during neural injury, suggesting a new role for these immune cells in brain healing. This study highlights Tie2 as a marker for microglial function in wound repair.
Area of Science:
- Neuroscience
- Immunology
- Molecular Biology
Background:
- Tie2 receptor tyrosine kinase is known in vascular development and cancer.
- Its role in the immune system, particularly in neural injury, is not well understood.
- Microglia are key immune cells in the central nervous system.
Purpose of the Study:
- To investigate the expression and role of Tie2 in microglia following acute neural injury.
- To explore Tie2 as a potential marker for microglial function during neuroinflammation and wound healing.
- To utilize noninvasive imaging techniques for longitudinal studies of neuroimmune responses.
Main Methods:
- Utilized magnetic resonance imaging (MRI) with the Ts-Biotag multimodal reporter mouse for noninvasive imaging.
- Conducted longitudinal studies to track Tie2 expression dynamics after neural injury.
- Employed labeled bone marrow chimeras to differentiate between resident microglia and infiltrating macrophages.
Main Results:
- Demonstrated Tie2 expression in microglia in response to acute neural injury.
- Identified key timepoints in wound signaling and healing through longitudinal imaging.
- Confirmed Tie2 expression is specific to brain-resident microglia, not invading macrophages.
Conclusions:
- Tie2 plays a previously unrecognized role in microglial function during neural wound healing.
- Noninvasive molecular imaging is a valuable tool for studying neuroimmune responses longitudinally.
- Tie2 serves as a unique marker for microglial activity in the context of brain injury and repair.
