Project description:Abstract Background Traumatic brain injury (TBI) results in irreversible damage at the site of impact and initiates cellular and molecular processes that lead to secondary neural injury in the surrounding tissue. We used microarray analysis to determine which genes, pathways and networks were significantly altered using a rat model of TBI. Adult rats received a unilateral controlled cortical impact (CCI) and were sacrificed 24h post-injury. The ipsilateral hemi-brain tissue at the site of the injury, the corresponding contralateral hemi-brain tissue, and naM-CM-/ve (control) brain tissue were used for microarray analysis. Ingenuity Pathway Analysis (IPA) software was used to identify molecular pathways and networks that were associated with the altered gene expression in brain tissues following TBI. Results Inspection of the top fifteen biological functions in IPA associated with TBI in the ipsilateral tissues revealed that all had an inflammatory component. IPA analysis also indicated that inflammatory genes were altered on the contralateral side, but many of the genes were inversely expressed compared to the ipsilateral side. The contralateral gene expression pattern suggests a remote anti-inflammatory molecular response. We created a network of the inversely expressed common (i.e., same gene changed on both sides of the brain) inflammatory response (IR) genes and those IR genes included in pathways and networks identified by IPA that changed on only one side. We ranked the genes by the number of direct connections each had in the network, creating a gene interaction hierarchy (GIH). Two well characterized signaling pathways, toll-like receptor/NF-kappaB signaling and JAK/STAT signaling, were prominent in our GIH. Conclusions Bioinformatic analysis of microarray data following TBI identified key molecular pathways and networks associated with neural injury following TBI. The GIH created here provides a starting point for investigating therapeutic targets in a ranked order that is somewhat different than what has been presented previously. In addition to being a vehicle for identifying potential targets for post-TBI therapeutic strategies, our findings can also provide a context for evaluating the potential of therapeutic agents currently in development. The ipsilateral hemi-brain tissue at the site of the injury, the corresponding contralateral hemi-brain tissue, and naM-CM-/ve (control) brain tissue (n=3 for each) were used for RNA isolation. The TBI injured animals were Todd 1, 2 Todd, and Todd 3, each yielding an ispilateral and contralateral sample. The naM-CM-/ve animals were Xu 13 control, Xu 2 control, and Xu 6 control.
Project description:Traumatic brain injury (TBI) triggers neuroinflammatory cascades mediated by microglia, which promotes tissue repair in the short-term. These cascades may exacerbate TBI-induced tissue damage and symptoms in the months to years post-injury. However, the progression of the microglial function across time post-injury and whether this differs between biological sexes is not well understood. In this study, we examined the microglial proteome in the days (3- and 7-days) to 1 month (28 days) after a midline fluid percussion injury (mFPI) in male and female mice using label-free quantitative proteomics. We identified a reduction in microglial proteins involved with clearance of neuronal debris via phagocytosis at 3- and 7-days post-injury. At 28 days post-injury pro-inflammatory proteins were decreased and anti-inflammatory proteins were increased in microglia. These results indicate a reduction in microglial clearance of neuronal debris in the days post-injury with a shift to anti-inflammatory function by 1 month. The changes in the microglial proteome that occurred across time post-injury did not differ between biological sexes. However, we did identify an increase in microglial proteins related to pro-inflammation as well as insulin and estrogen signalling in males compared with female mice that occurred with or without a brain injury. Although microglial response was similar between males and females up to 1 month following TBI, biological sex differences in the basal microglial proteome has implications for the efficacy of treatment strategies targeting the microglial response post-injury.
Project description:Abstract Background Traumatic brain injury (TBI) results in irreversible damage at the site of impact and initiates cellular and molecular processes that lead to secondary neural injury in the surrounding tissue. We used microarray analysis to determine which genes, pathways and networks were significantly altered using a rat model of TBI. Adult rats received a unilateral controlled cortical impact (CCI) and were sacrificed 24h post-injury. The ipsilateral hemi-brain tissue at the site of the injury, the corresponding contralateral hemi-brain tissue, and naïve (control) brain tissue were used for microarray analysis. Ingenuity Pathway Analysis (IPA) software was used to identify molecular pathways and networks that were associated with the altered gene expression in brain tissues following TBI. Results Inspection of the top fifteen biological functions in IPA associated with TBI in the ipsilateral tissues revealed that all had an inflammatory component. IPA analysis also indicated that inflammatory genes were altered on the contralateral side, but many of the genes were inversely expressed compared to the ipsilateral side. The contralateral gene expression pattern suggests a remote anti-inflammatory molecular response. We created a network of the inversely expressed common (i.e., same gene changed on both sides of the brain) inflammatory response (IR) genes and those IR genes included in pathways and networks identified by IPA that changed on only one side. We ranked the genes by the number of direct connections each had in the network, creating a gene interaction hierarchy (GIH). Two well characterized signaling pathways, toll-like receptor/NF-kappaB signaling and JAK/STAT signaling, were prominent in our GIH. Conclusions Bioinformatic analysis of microarray data following TBI identified key molecular pathways and networks associated with neural injury following TBI. The GIH created here provides a starting point for investigating therapeutic targets in a ranked order that is somewhat different than what has been presented previously. In addition to being a vehicle for identifying potential targets for post-TBI therapeutic strategies, our findings can also provide a context for evaluating the potential of therapeutic agents currently in development.
Project description:Remote ischemic conditioning (RIC) treatment has been shown to modify levels of traumatic brain injury (TBI) pathology related proteins, however, the mechanism is not widely understood. This study utilized LC-MS/MS to identify protein biomarkers of RIC treatment after TBI in mouse models.
Project description:Traumatic brain injury (TBI) induces a complex cascade of molecular and physiological effects. This study proposes to investigate the gene expression profile in cortex and hippocampus over early time points, following two different injury severities. These results will complement prior knowledge of both metabolic and neuroplastic changes after TBI, as well as serve as a starting point to investigate additional gene families whose expression is altered after TBI.,To characterize the profile of gene expression following a diffuse traumatic brain injury of varying severity in adult rats. ,Distinct patterns of gene expression following traumatic brain injury will occur in a time- and injury-dependent fashion. In particular, changes in expression of enzymes involved in energy metabolism and neuroplasticity will be detected.,Adult rats will be subjected to mild and severe lateral fluid percussion injury OR sham surgery without injury. At various post-injury timepoints (0.5, 4 and 24 hours), animals will be sacrificed, brain regions (parietal cortex and hippocampus, ipsilateral and contralateral to injury) will be dissected and RNA isolated. RNA will be used to synthesize cRNA probes for microarray hybridization. RNA from 2 matched animals will be pooled onto a single chip (U34A rat, Affymetrix). Comparisons will be made between sham and injured animals, with brain region, injury severity, and post-injury time point as the experimental variables.
Project description:Ten-week-old C57BL/6J mice were subjected to unilateral hind limb ischemia-reperfusion (I/R) injury by postural suspension method for 4 hours, and then treated with aspirin anti-inflammatory group and peptide functionalized hydrogel drug. RNA-seq analysis was then performed.
Project description:Traumatic brain injury (TBI) initiates a complex sequence of destructive and neuroprotective cellular responses. The initial mechanical injury is followed by an extended time period of secondary brain damage. Due to the complicated pathological picture a better understanding of the molecular events occurring during this secondary phase of injury is needed. This study was aimed at analysing gene expression patterns following cerebral cortical contusion in rat using high throughput microarray technology with the goal of identifying genes involved in an early and in a more delayed phase of trauma, as genomic responses behind secondary mechanisms likely are time-dependent. Keywords: Traumatic brain injury, genomic response
Project description:Traumatic brain injury (TBI) induces a complex cascade of molecular and physiological effects. This study proposes to investigate the gene expression profile in cortex and hippocampus over early time points, following two different injury severities. These results will complement prior knowledge of both metabolic and neuroplastic changes after TBI, as well as serve as a starting point to investigate additional gene families whose expression is altered after TBI. To characterize the profile of gene expression following a diffuse traumatic brain injury of varying severity in adult rats. Distinct patterns of gene expression following traumatic brain injury will occur in a time- and injury-dependent fashion. In particular, changes in expression of enzymes involved in energy metabolism and neuroplasticity will be detected. Adult rats will be subjected to mild and severe lateral fluid percussion injury OR sham surgery without injury. At various post-injury timepoints (0.5, 4 and 24 hours), animals will be sacrificed, brain regions (parietal cortex and hippocampus, ipsilateral and contralateral to injury) will be dissected and RNA isolated. RNA will be used to synthesize cRNA probes for microarray hybridization. RNA from 2 matched animals will be pooled onto a single chip (U34A rat, Affymetrix). Comparisons will be made between sham and injured animals, with brain region, injury severity, and post-injury time point as the experimental variables. Keywords: time-course
Project description:Efficient growth cone regeneration requires protein synthesis in the adult mammalian brain and spinal cord. Recent evidence suggests that the local availability of protein synthesis machinery in adult mammalian axons may be an indicator of their regenerative capacity. Here we investigated the local protein synthesis capacity in matured cortical axons, which have poor regenerative capacity, yet are critical for recovery following injury due to traumatic brain injury and stroke. This work is the first to biochemically isolate and identify mRNA from mammalian cortical axons, making use of a unique microfluidic platform to isolate axons free of other cellular debris. We first sought to identify mRNA in naïve axons that makes up the pool of mRNA available for translation initiated following axotomy. Next, we investigated changes in the mRNA population localized to axons 2 days following axotomy and growth cone regeneration. Keywords: axonal expression analysis; injury state analysis
Project description:Traumatic brain injury (TBI) alters and dysregulates the expression of thousands of genes in the brain. Since some of the most common problems in TBI patients are learning and memory deficits, we are studying the effects of TBI on the hippocampus, a region of the brain which is essential for learning and memory and which is known to be particularly vulnerable to TBI. We are interested in understanding how potential neuroprotective drugs alter the TBI-induced gene expression profile. The objective of this study is to elucidate and compare the differential gene expression profiles in the hippocampus of naive, sham-control, TBI and TBI plus drug treated rats. JM6, PMI-006 and E33 are three compounds with neuroprotective, anti-inflammatory and anti-oxidative effects. Our goal is to determine if different neuroprotective compounds have similar effects on common gene targets. These genes and the cell signaling pathways linked to them would then be the target of new therapeutic strategies for TBI. Rats were prepared for fluid percussion traumatic brain injury or sham injury (naïve rats had no anesthesia and were not handled in any way and gene expression in their brains serve as baseline data) and 24 hr post-injury, hippocampi were obtained, and stored in RNA later. Total RNA was isolated, quantitified and used for Agilent microarray analysis at GenUs Biosystems. Each group of naive, sham control, TBI and TBI plus JM6, TBI plus PMI-006 and TBI plus E33 (estrogen) has three biological replicates.