Profiling neuroimmune cascade in male and female 3xTg mice exposed to successive weight drop closed-head injuries

STUDY PURPOSE: Repetitive mild traumatic brain injuries (rmTBI) sustained within a window of vulnerability (up to a month after initial injury) can result in long term cognitive deficits, depression, and eventual neurodegeneration associated with tau pathology, amyloid beta plaques, gliosis, and neuronal and functional loss. However, we have limited understanding of how successive injuries affect the brain to result in these devastating long-term consequences. In the current study, we addressed the question of how repeated injuries affect the brain in the acute phase of injury (<24hr) by exposing the 3xTg-AD mouse model of tau and amyloid beta pathology to successive (1x, 3x, 5x) once-daily weight drop closed-head injuries and quantifying immune markers, pathological markers, and transcriptional profiles at 30min, 4hr, and 24hr after each injury. DATA COLLECTED: Time points included pre-injury and 30min, 4hr, and 24hr post-injury for 1x, 3x, and 5xCHI. This work was conducted using a weight drop closed-head injury model. Animals were anesthetized using 4.5% isoflurane (1 L/min, 70/30 nitric oxide/oxygen) prior to injury. The injury was delivered by a 54 g bolt dropped from the top of a vertically mounted 38in guide tube targeted to the dorsal aspect of the intact skull, between the coronal and lambdoid structures. Control sham-injured mice were age- and sex- matched and received the same exposure to anesthesia but were not subject to closed-head injury. Cerebral blood flow was measured immediately prior to animal sacrifice by non-invasive diffuse correlation spectroscopy while under isoflurane. Mice were anesthetized and decapitated, then the brain was extracted and microdissected. The left frontal cortex, somato-motor cortex, and hippocampus were flash-frozen and stored until lysis for molecular analysis.
Cytokines, MAPK, amyloid beta, and tau from frontal cortex and hippocampus brain lysate by Luminex ELISA
GFAP, S100B, CD68, TMEM119 from frontal cortex and hippocampus brain lysate by ELISA
NOTE: Male and female samples run in separate batches except for S100B, CD68, and TMEM119 ELISAs; eight female samples were measured in both female and male batch assays as technical replicates.
Gene expression data from female somato-motor cortex brain lysate can be accessed in the Gene Expression Omnibus (GEO) repository under series record GSE226838. DATA USAGE NOTES: