Description
- Abstract:
- About 1.5 million people in the US sustain a Traumatic Brain Injury (TBI), with 80-90% of those being mild traumatic brain injuries (mTBIs). mTBIs are characterized by headaches, dizziness and impaired memory. TBI is followed by cellular events such as excitotoxicity, free radical creation, and neuroinflammation in the brain. Neuroinflammation in particular is one of the most common and important consequences of TBI. Microglia play a key role in neuroinflammation, as they are the primary immune effector cells within the CNS microenvironment. Following injury, microglia changes from resting-state to an activated state, resulting in a change in morphology. The activated state falls on an activation spectrum between two major phenotypes, commonly classified as M1 or M2, which describe its pro-inflammatory and anti-inflammatory states respectively. This study employs a three-dimensional (3D) neural spheroid model that was developed by the Hoffman-Kim laboratory, that mimics the brain microenvironment. Centrifugal injuries at 4,000 revolutions per minute (RPM) were applied to the spheroids to mimic the mTBI, with either single injury or three consecutive injuries for repeated conditions. These spheroids were then fixed at various time points ranging from immediately after injury at 0H to 7 DPI (days post injury). These spheroids were then stained for CD86 and CD16 as M1 markers, and CD206 as an M2 marker. In order to determine the microglia’s resting state, the P2Y12 receptor is used, as it is a microglia-specific marker that is highly expressed in the resting state of microglia. In this study, the total mean pixel intensities and sphericities for the spheroids were calculated using ImageJ, and it found that there was a significant difference in total mean pixel intensities and sphericities for three repeated injury conditions stained for P2Y12R. Significant differences were found in total mean pixel intensities and sphericities between 0H and 7DPI in repeated conditions for CD206, but there were no other significant differences found in the rest of the CD206 conditions tested. CD86 and CD16 were not detected at any of the tested conditions. This study establishes a 3D spheroid model to study neuroinflammatory markers for microglia in both single and repeated mTBI injuries, particularly looking at mean pixel intensities of the stainings as well as the morphology.
- Notes:
- Thesis (Sc. M.)--Brown University, 2022
Citation
Okazaki, Lisa,
"Modeling Microglia Activation in Neuroinflammation in 3D Neuronal Spheroids After Single and Repeated Mild Traumatic Brain Injury"
(2022).
Biomedical Engineering Theses and Dissertations.
Brown Digital Repository. Brown University Library.
https://repository.library.brown.edu/studio/item/bdr:ppm7vhzc/
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Biomedical Engineering Theses and Dissertations
Theses and Dissertations for the Biomedical Engineering department....