Project description:Expression of 757 neuroinflammaiton-associated genes in vehicle and complement inhibitor treated TBI brains at days 3, 7 and 28 post injury
Project description:We inflicted TBI to chemokine-deficient mouse lines in order to establish involvement of various signalling pathways that may be addressed therapeutically. Interacting chemokine pathways in brain regulate distinct inflammatory cells. Activated microglia are separate from invading phagocytes and dendritic cells. Findings show potential targets to interfere with specific inflammatory responses after brain injury. TBI was carried out in Ccl3-/- and Ccr2-/- mice, total RNA prepared from injured cerebral neocortex after three days. RNA samples were from uninjured Ccl3-/- and Ccr2-/- mice as reference for hybridization on Affymetrix microarrays.
Project description:The variations of psycho- and physiological deficits caused by TBI correlate with the degree of brain injury. However, the objective stratification of TBI is yet elusive. A modified closed-head injury Marmarou model was used based on the release of a 500 gram steel slug on top of the rat skull from a height of 100 cm or 120 cm to induce differential injury models for mild TBI and moderate TBI, respectively. The skull was covered by a helmet to mimic the warfighter’s condition in theater. The hippocampus was at the focal point of injury, and the cerebellum, was susceptible to diffused shock (secondary injury). The HC-CB axis coordinates visuomotor performance, which is known to be vulnerable to TBI. The rats that received moderate TBI showed deficient visuomotor performance by the Barnes maze test for longer time periods than those inflicted with mild TBI. The time resolved and HC-CB specific transcriptomic analysis focused on genes that enabled discrimination of mild from moderate TBI at 14d post injury which is equivalent to nearly 1.5 years of human lifetime. The functional analysis elucidated an active healing mechanism in the HC exposed to mild TBI. In contrast, moderate TBI caused delayed healing and active cell death in the HC. In conclusion, the graded brain injuries differentially implicated the HC-CB axis, despite the use of a helmet to reduce the impact. Time resolved functional dynamics informed the distinct consequences of mild vs. moderate TBI.
Project description:TBI causes the disruption of blood vessels in brain leading to hemorrhage, edema, and changes in cerebral blood flow. How such altered vascular and flow condition affect endothelial cells, the cellular unit of blood vessels, is not known. We used single cell RNA sequencing (scRNAseq) to analyze the heterogenity in endothelial cell clusters in brain, and how key cellular and signaling signatures of these clusters are temporally changed post-TBI at the site of injury.
Project description:We inflicted TBI to wildetype (wt) mice in order to establish whether the anti-inflammatory agent cyclophosphamide can be used therapeutically. Cyclophosphamide was found to regulate distinct inflammatory cells such as activated microglia separate from invading phagocytes and dendritic cells. Cyclophosphamide postinjury selectively reduces antigen-presenting dendritic cells. Findings show feasibility of drug development to interfere with brain inflammation. TBI was carried out in injured wt B6 mice for postinjury treatment with cyclophospamide i.p. using saline as a control substance for comparison with injured but untreated mice. Total RNA was prepared from injured cerebral neocortex after three days. RNA samples were also from uninjured wt mice as reference for hybridization on Affymetrix microarrays.
Project description:We inflicted TBI to chemokine-deficient mouse lines in order to establish involvement of various signalling pathways that may be addressed therapeutically. Interacting chemokine pathways in brain regulate distinct inflammatory cells. Activated microglia are separate from invading phagocytes and dendritic cells. Findings show potential targets to interfere with specific inflammatory responses after brain injury.
Project description:Traumatic brain injury (TBI) causes hospitalizations and mortality worldwide with no approved neuroprotective treatments available, partly due to a poor understanding of the molecular mechanisms underlying TBI neuropathology and neuroprotection. We previously reported that the administration of low-dose methamphetamine (MA) induced significant functional/cognitive improvements following severe TBI in rats. We further demonstrated that MA mediates neuroprotection in part, via dopamine-dependent activation of the PI3K-AKT pathway. Here, we further investigated the proteomic changes within the rat cortex and hippocampus following mild TBI (TM), severe TBI (TS), or severe TBI plus MA treatment (TSm) compared to sham operated controls (n=78 in total). We quantified >7,000 unique proteins in total and identified 402 and 801 altered proteins (APs) with high confidence in cortical and hippocampal tissues, respectively. The overall profile of APs observed in TSm rats more closely resembled those seen in TM rather than TS rats. Pathway analysis suggested beneficial roles for acute signaling through IL-6, TGFβ, and IL-1β. Moreover, changes in fibrinogen levels observed in TSm rats suggested a potential role for these proteins in reducing/preventing TBI-induced coagulopathies. These data facilitate further investigations to identify specific pathways and proteins that may serve as key targets for the development of neuroprotective therapies.