Evidence for a rheostat that determines neuronal survival after traumatic brain injury
Ontology highlight
ABSTRACT:
ORGANISM(S): Rattus norvegicus
PROVIDER: GSE16735 | GEO | 2010/12/20
SECONDARY ACCESSION(S): PRJNA117425
REPOSITORIES: GEO
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Project description:To investigate the determinants of neuronal survival after traumatic brain injury, we compared the transcriptional profiles of dying (Fluoro-Jade-positive) and immediately adjacent surviving (Fluoro-Jade-negative) neurons from the CA3 subfield of the rat hippocampus 24 hours after experimental TBI. We found that hippocampal neurons that survive TBI invariably express high levels of genes that have cellular functions involved in survival, regeneration, development, proliferation, neuronal plasticity such as cAMP response element binding protein (CREB), brain-derived-neurotrophic factor (BDNF) and mitogen-activated protein kinase 1 (MAPK1). Dying neurons express high levels of genes involved in aberrant cell cycle progression, immune response, inflammation, oxidative stress and apoptosis such as Interleukin-1β (IL-1β), caspase 3 and B-cell linker (BLNK). We conclude that shifting the balance between the global levels of these proteins with pharmacotherapeutic drugs that induce expression of cell survival associated genes, is expected to alter the cellular rheostat that determines cell survival or cell death. Replicate pooled samples (approximately 600 laser capture microdissected hippocampal neurons per sample of dying neurons (labeled with Fluoro-Jade, a fluorescent stain for degenerating CNS neurons) and surviving neurons (Fluoro-Jade-negative) were hybridized in duplicate to rat Agilent whole genome arrays.
2010-12-20 | E-GEOD-16735 | biostudies-arrayexpress
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2022-06-30 | GSE190426 | GEO
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.
2021-03-02 | PXD024317 | Pride
Project description:We compared arginase-1+ macrophages (macrophages were defined by flow cytometry as CD45hi CD11b+ Ly6G-) with arginase-1- brain macrophages following traumatic brain injury (TBI) by isolating these cells from YARG transgenic mice, which express YFP under the arginase-1 promoter. Both cell populations were isolated from YARG brain tissues one day following TBI. We also examined the expression profile of peripheral blood monocytes (monocytes were defined by flow cytometry as CD11bhi F4/80+) from injured YARG mice and from normal YARG mice. Peripheral blood samples were compared to TBI brain macrophages to assess gene expression changes before and after infiltration into the brain. TBI macrophage subsets were identified by using a reporter mouse strain (YARG) that expresses eYFP from an IRES inserted at the 3' end of the gene for arginase-1 (Arg1), a hallmark of alternatively activated (M2) macrophages. One day after TBI, 21±1.5% of ipsilateral brain macrophages expressed relatively high levels of Arg1 as detected by YFP. Gene expression analysis of Arg1+ and Arg1- brain macrophage populations revealed that these populations were distinct from either classically activated (M1) macrophages or M2 macrophages, with features of both. The Arg1+ cells differed from Arg1- cells in multiple aspects, most notably in their chemokine repertoires. Thus, the macrophage response to TBI involves recruitment of at least two major macrophage subsets. Overall, our data indicate that the macrophage response to TBI is heterogeneous and unique. Four groups (Arg1- brain macrophages post-TBI, Arg1+ brain macrophages post-TBI, normal blood monocytes, blood monocytes post-TBI) were analyzed. Four replicates of each group were analyzed for a total of 16 samples (only 3 replicates of the blood monocyte groups are included in this submission).
2013-05-01 | E-GEOD-39759 | biostudies-arrayexpress
Project description:Caspase-1 signaling in myeloid suppressor cells can promote T-cell independent cancer progression, but the regulation of inflammasome signaling within the highly heterogeneous myeloid cells in the tumor milieu remains elusive. To resolve this complexity, scRNA-seq of human head & neck carcinoma identified distinct inflammasome complex genes within specific clusters of tumor-infiltrating myeloid cells. Among these myeloid cells, NLRP3 sensor and downstream effector IL-1β transcripts were enriched in multiple monocytic and macrophage subtypes in the TME. In vivo, we showed that NLRP3, and not AIM2, phenocopied the caspase-1/IL-1β dependent tumor progression. Paradoxically, we found that myeloid-intrinsic caspase-1 signaling within the TME increased myeloid survival without significant intratumoral trafficking as would be predicted from their canonical pyroptotic function. Mechanistically, this myeloid NLRP3/IL-1β signaling axis promotion of tumor growth was found to be gasdermin D independent. When we probed for the tumor intrinsic factors that regulated NLRP3/IL-1β signaling, we found that mononuclear phagocyte-mediated efferocytosis of dying tumor cells in the TME directly activated NLRP3 dependent inflammasome signaling to drive IL-1β secretion and to promote tumor growth. Dynamic RNA velocity analysis of the single cell transcriptomic dataset showed a strong directional flow from efferocytosis gene-sethigh macrophages to an inflammasome gene-sethigh macrophage population. Cumulatively, we provide a novel inflammasome signaling axis between tumor apoptosis and myeloid cells that characterizes chronic inflammation induced malignancy.
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Project description:Traumatic axonal injury (TAI) in the brainstem carries a particularly poor prognosis. Although the role of neuroinflammation in this process is incompletely characterized, astrogliosis has been shown to coincide with TAI. Moreover, astrogliotic forebrain astrocytes were recently shown to confer a toxic effect on neurons. We sought to assess if ventral brainstem- or rostroventral spinal astrocytes exert similar effects on motor neurons in vitro. We derived brainstem/rostroventral spinal astrocyte-like cells (ES-astrocytes) and motor neurons using directed differentiation of embryonic stem cells (ES). ES-astrocyte identity was assessed using RNA-sequencing, immunocytochemistry, and comparison with primary subventricular zone-astrocytes. We activated the ES-astrocytes using the neurotoxicity-eliciting cytokines interleukin- (IL-) 1α and tumor necrosis factor-(TNF-)α. In co-cultures with reactive ES-astrocytes and motor neurons, we demonstrated neurotoxic ES-astrocyte activity, similarly to what has previously been shown for other central nervous system (CNS) regions. When exposed to IL-1β and IL-6, two neuroinflammatory cytokines found in the cerebrospinal fluid and serum proteome following severe traumatic brain injury (TBI), ES-astrocytes exerted similar effects on motor neurons. This demonstrates that ventral brainstem and rostroventral spinal cord astrocytes can exert neurotoxic effects in vitro. This highlights the importance of neuroinflammation as a secondary injury mechanism following neurotrauma, and presents a possible treatment avenue to improve neuronal survival in particularly vulnerable CNS regions following TAI.
2023-04-02 | GSE213804 | GEO
Project description:The cAMP responsive element binding protein (CREB) pathway has been involved in two major cascades of gene expression regulating neuronal function. The first one presents CREB as a critical component of the molecular switch that control longlasting forms of neuronal plasticity and learning. The second one relates CREB to neuronal survival and protection. To investigate the role of CREB-dependent gene expression in neuronal plasticity and survival in vivo, we generated bitransgenic mice expressing A-CREB, an artificial peptide with strong and broad inhibitory effect on the CREB family, in forebrain neurons in a regulatable manner. The expression of ACREB in hippocampal neurons impaired L-LTP, reduced intrinsic excitability and the susceptibility to induced seizures, and altered both basal and activity-driven gene expression. In the long-term, the chronic inhibition of CREB function caused severe loss of neurons in the CA1 subfield as well as in other brain regions. Our experiments confirmed previous findings in CREB deficient mutants and revealed new aspects of CREB-dependent gene expression in the hippocampus supporting a dual role for CREB-dependent gene expression regulating intrinsic and synaptic plasticity and promoting neuronal survival. manufacturer's protocol. Experiment Overall Design: Each sample contained total RNA from the hippocampi of a group of 3-4 three weeks old mice. We obtained duplicate samples for each experimental condition (in total 14 WT and 20 A-CREB mice where used in this experiment). Mouse Genome 430 2.0 genechips were hybridized, stained, washed and screened for quality according to the manufacturer's protocol.
2009-01-17 | E-GEOD-14320 | biostudies-arrayexpress
Project description:The current lack of proven pharmacological treatment options for traumatic brain injury (TBI) patients reflects the poor translation of successful preclinical studies in clinical trials. This may be due to poor choice of therapeutic agents based on incomplete knowledge of critical elements of neuroprotection. Our goal is to expedite discovery and translation of therapeutic agents that can improve functional outcome by identifying the common molecular profile of neuroprotective drugs. Since damage to the hippocampus is associated with TBI-induced deficits in learning and memory, we analyzed of the hippocampal transcriptional profiles of TBI rats treated with two clinically used drugs metyrapone and carbenoxolone, which have been shown to improve cognitive deficits in previous studies. Despite their different structures, we found that MT and CB have similar effects on several known biological pathways. The neuroprotective effects of these drugs are associated with a distinctive molecular signature which is characterized not by changes in expression of any individual gene but by a common global effect on multiple cell signaling pathways. These data suggest that drug treatments that induce a coordinated attenuation of multiple injury-induced cell signaling networks, both deleterious and protective, have high translational potential. There were 16 samples for array analysis, two biological replicates each for control (4 and 24 hour), TBI (4 and 24 hour), TBI plus MT (4 and 24 hour) and TBI plus CB (4 and 24 hour). Each biological sample, which is a pooled RNA sample (laser captured CA3 pyramidal neurons) from the hippocampus of 3-6 rats, was hybridized to duplicate arrays so that there were 32 gene arrays in this study.
2012-12-23 | E-GEOD-31357 | biostudies-arrayexpress
Project description:The cAMP responsive element binding protein (CREB) pathway has been involved in two major cascades of gene expression regulating neuronal function. The first one presents CREB as a critical component of the molecular switch that control longlasting forms of neuronal plasticity and learning. The second one relates CREB to neuronal survival and protection. To investigate the role of CREB-dependent gene expression in neuronal plasticity and survival in vivo, we generated bitransgenic mice expressing A-CREB, an artificial peptide with strong and broad inhibitory effect on the CREB family, in forebrain neurons in a regulatable manner. The expression of ACREB in hippocampal neurons impaired L-LTP, reduced intrinsic excitability and the susceptibility to induced seizures, and altered both basal and activity-driven gene expression. In the long-term, the chronic inhibition of CREB function caused severe loss of neurons in the CA1 subfield as well as in other brain regions. Our experiments confirmed previous findings in CREB deficient mutants and revealed new aspects of CREB-dependent gene expression in the hippocampus supporting a dual role for CREB-dependent gene expression regulating intrinsic and synaptic plasticity and promoting neuronal survival. manufacturer's protocol.
2009-01-12 | GSE14320 | GEO
Project description:Partial tendon-to-bone interface (TBI) injuries heal in a mechanically inferior manner and redevelop healthy uninjured tissue morphology. The origin of the cells involved in tendon-to-bone healing remains unknown. We employed a rigorous approach to evaluate if mouse skeletal stem cells (mSSC) play a role in tendon-to-bone healing after partial-injury. Using fluorescence-activated cell sorting we identified that found that they are present within the TBI. Using a TBI-injury rainbow lineage tracing mouse model, we demonstrated that injury-responsive cells within the TBI and calcaneus proliferate polyclonally following partial-tendon injury at the TBI. These injury-responsive clonal cells express skeletal marker SP7. We quantified the differences in mSCC frequency after TBI-injury and found that mSSC respond to injury with a higher frequency and have associated changes in gene expression, with the specific down-regulation of the TGFβ signaling pathway. Exogenous delivery of TGFβ after injury was found to reduce the mSSC response after injury. These findings suggest that mSSC may facilitate tendon-to-bone healing by downregulating TGFβ signaling within the mSSC niche.
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