Characterization of Macrophages M1/M2 Phenotypes in Acute and Chronic Microenvironments
after SCI
Joel A Trushinski
Mentors: Aileen Anderson, Hal Nguyen
Traumatic spinal cord injury is caused by the initial physical trauma to the cord, followed by infiltration of
immune cells (e.g., macrophages) that can be harmful or beneficial to SCI and functional outcome. However,
the characterization or phenotypes associated with these macrophages have not been clearly defined after
SCI. It has been suggested that M1 infiltrate the cord early post-SCI with cytotoxic and pro-inflammatory
functions. In contrast, M2 come in later with anti-inflammatory and repair/regeneration functions. With
respect to M1/M2 characterization after SCI, we hypothesize that M1 invade the cord acutely, while M2
come in chronically after SCI. Previously, we showed evidence of a proportionally increasing M2 population
(relative to M1) after chronic SCI at 60 and 90 days post-injury (dpi). Since then, I have further validated this,
increasing M2 phenotypes at 60dpi verses an increasing M1 phenotypes at 7dpi using immunofluorescent
labeling for CD68/iNOS to identify M1 and CD68/CD163 to identify M2. In all, our data show an alteration
of M1/M2 phenotypes in the spinal cord from acute to chronic SCI.