Project description:Many extracellular matrix (ECM) changes occur in the brain after traumatic brain injury. This work sought to understand the dynamics of ECM modifications after TBI by comparing RNA transcription between ipsilateral and contralateral brain regions. Mice underwent controlled cortical impact (with a 2mm depth) using a pneumatic impactor. Seven days later, brain tissue was harvested from the site of injury and from the corresponding contralateral cortex. Microarrays were used to measure gene expression to compare these tissues.
Project description:Here we investigated the topographical relationship of early transcriptional responses to a single, focal TBI in mice by controlled cortical impact (CCI). Guided by the presence of the anterior commissure (AC) in coronal sections at the rostro-caudal point of impact, we compared gene expression changes in the neocortex (CTX) and corpus callosum-external capsule (CC-EC), striatum (STR) and AC. Injury-induced gene expression changes were detected in the CTX, CC-EC and STR but not AC and were principally segregated based on cytoarchitecture, and secondarily by proximity to the site of impact. Additionally, unbiased spatial clustering revealed a positive relationship between proximity to the impact and the number of acutely differentially expressed genes within the laminar CTX. Next, we examined the effects of systemic depletion of neutrophils and monocytes on spatial gene expression changes in the injured brain.
Project description:We report the miRNAs differentially expressed in the orbitofrontal cortex of adult male rats 5 weeks after a controlled cortical injury model of traumatic brain injury (TBI). Animals underwent 3 repeated mild injuries on days 1, 4 and 7. Tissue was collected on day 42.
Project description:To elucidate the epigenomic features of hippocampal cells following mTBI, approximately 50,000 nuclei were profiled from matched hippocampal tissues of three mice subjected to controlled cortical impact (CCI) and three sham-operated controls. Cell type-specific chromatin accessibility changes in response to mTBI were identified.
Project description:Neuroprotective potential of intranasally delivered L-myc immortalized human neural stem cells in female rats after a controlled cortical impact injury
Project description:Traumatic brain injury (TBI) causes transient increases and subsequent decreases in brain glucose utilization. The underlying molecular pathways are orchestrated processes and poorly understood. In the current study, we determined temporal changes in cortical and hippocampal expression of genes important for brain glucose/lactate metabolism and the effect of a known neuroprotective drug telmisartan on the expression of these genes after experimental TBI. Adult male C57BL/6J mice (n?=?6/group) underwent sham or unilateral controlled cortical impact (CCI) injury. Their ipsilateral and contralateral cortex and hippocampus were collected 6?h, 1, 3, 7, 14, 21, and 28?days after injury. Expressions of several genes important for brain glucose utilization were determined by qRT-PCR. In results, (1) mRNA levels of three key enzymes in glucose metabolism [hexo kinase (HK) 1, pyruvate kinase, and pyruvate dehydrogenase (PDH)] were all increased 6?h after injury in the contralateral cortex, followed by decreases at subsequent times in the ipsilateral cortex and hippocampus; (2) capillary glucose transporter Glut-1 mRNA increased, while neuronal glucose transporter Glut-3 mRNA decreased, at various times in the ipsilateral cortex and hippocampus; (3) astrocyte lactate transporter MCT-1 mRNA increased, whereas neuronal lactate transporter MCT-2 mRNA decreased in the ipsilateral cortex and hippocampus; (4) HK2 (an isoform of hexokinase) expression increased at all time points in the ipsilateral cortex and hippocampus. GPR81 (lactate receptor) mRNA increased at various time points in the ipsilateral cortex and hippocampus. These temporal alterations in gene expression corresponded closely to the patterns of impaired brain glucose utilization reported in both TBI patients and experimental TBI rodents. The observed changes in hippocampal gene expression were delayed and prolonged, when compared with those in the cortex. The patterns of alterations were specific to different brain regions and exhibited different recovery periods following TBI. Oral administration of telmisartan (1?mg/kg, for 7?days, n?=?10 per group) ameliorated cortical or hippocampal mRNA for Glut-1/3, MCT-1/2 and PDH in CCI mice. These data provide molecular evidence for dynamic alteration of multiple critical factors in brain glucose metabolism post-TBI and can inform further research for treating brain metabolic disorders post-TBI.