Genetics in experimental traumatic brain injury

Traumatic brain injury (TBI) is the leading cause of death and disability in the young population in the industrialized world. It comprises a heterogeneous group of brain pathologies where head trauma initiates a series of complex molecular pathways, which, together with the initial injury, account for the final outcome. Although extensive research has shed some light on these pathways, they are still incompletely understood. No pharmacological treatment for TBI exists. This project was initiated to study a possible impact of genetic heterogeneity in experimental TBI and identify genes/loci that regulate the secondary TBI pathways and outcome. Brain contusion was induced using the weight drop injury (WDI) model in inbred and congenic rat strains. Inflammatory pathways, infiltration of neutrophils, NK cells and monocytes/macrophages and activation of microglia and the complement pathway were found to be regulated by non-MHC (Major Histocompatibility Complex) genes. Non-MHC genes did also influence neurodegeneration, and interestingly, a stronger inflammatory response was correlated to a more vigorous neuronal/axonal injury and neurodegenerative outcome. Further, the use of congenic rats with loci harboring the Ciita gene or the MHC-gene complex, revealed that mainly MHC genes regulate MHC-II presentation after TBI with a smaller contribution from Ciita, and also that MHC genes regulate a delayed T cell infiltration after TBI, suggesting a role for adaptive immune responses and autoimmunity in TBI. We used various genetic mapping approaches to disclose genes that regulate neurodegeneration in a rat ventral root avulsion (VRA) model and found that glutathione-S-transferase alpha 4 (Gsta4) is a candidate gene for regulating motorneuron death in this model. Levels of Gsta4 were genetically regulated by a variation in the Gsta4 gene region and had an inverse correlation to the degree of neurodegeneration. This effect of Gsta4 gene variation was replicated in experimental TBI where it regulated the degree of hippocampal neuronal cell loss. Gsta4 exerts its effect possibly via more efficient detoxification of the highly reactant product of lipid peroxidation, 4-hydroxynonenal (4-HNE). The presence of 4-HNE was demonstrated in experimental TBI and also in human pericontusional tissue providing evidence for the importance of the Gsta4 – 4HNE pathway also in human TBI. Taken together, the findings in both VRA and TBI suggest that the Gsta4 - 4-HNE detoxification pathway can be important, not only in TBI, but possibly also in other neurodegenerative diseases. Alltogether, the findings of this thesis demonstrate that genetic heterogeneity has a substantial impact on the secondary pathways and outcome in experimental TBI and highlight the need for further research in the field of genetics in TBI

PENGEMBANGAN KEMAMPUAN PROBLEM SOLVING MELALUI PEMBELAJARAN TOPIK OPTIKA FISIS BAGI MAHASISRVA CALON GURU FRISIKA

Traumatic brain injury (TBI) is a common cause of death and disability, worldwide. Early determination of injury severity is essential to improve care. Neurofilament light (NF-L) has been introduced as a marker of neuroaxonal injury in neuroinflammatory/-degenerative diseases. In this study we determined the predictive power of serum (s-) and cerebrospinal fluid (CSF-) NF-L levels towards outcome, and explored their potential correlation to diffuse axonal injury (DAI). A total of 182 patients suffering from TBI admitted to the neurointensive care unit at a level 1 trauma center were included. S-NF-L levels were acquired, together with S100B and neuron-specific enolase (NSE). CSF-NF-L was measured in a subcohort (n = 84) with ventriculostomies. Clinical and neuro-radiological parameters, including computerized tomography (CT) and magnetic resonance imaging, were included in the analyses. Outcome was assessed 6 to 12 months after injury using the Glasgow Outcome Score (1-5). In univariate proportional odds analyses mean s-NF-L, -S100B and -NSE levels presented a pseudo-R-2 Nagelkerke of 0.062, 0.214 and 0.074 in correlation to outcome, respectively. In a multivariate analysis, in addition to a model including core parameters (pseudo-R-2 0.33 towards outcome; Age, Glasgow Coma Scale, pupil response, Stockholm CT score, abbreviated injury severity score, S100B), S-NF-L yielded an extra 0.023 pseudo-R-2 and a significantly better model (p = 0.006) No correlation between DAI or CT assessed-intracranial damage and NF-L was found. Our study thus demonstrates that SNF-L correlates to TBI outcome, even if used in models with S100B, indicating an independent contribution to the prediction, perhaps by reflecting different pathophysiological processes, not possible to monitor using conventional neuroradiology. Although we did not find a predictive value of NF-L for DAI, this cannot be completely excluded. We suggest furthe

Результаты паратиреоидной аллотрансплантации

АЛЛОТРАНСПЛАНТАЦИЯГИПОПАРАТИРЕОЗИММУНОСУПРЕССИЯПАРАЩИТОВИДНЫЕ ЖЕЛЕЗЫ /хирТКАНЕВАЯ ТЕРАПИ

Lipocalin-2 is increased in progressive multiple sclerosis and inhibits remyelination

Objective: We aimed to examine the regulation of lipocalin-2 (LCN2) in multiple sclerosis (MS) and its potential functional relevance with regard to myelination and neurodegeneration. Methods: We determined LCN2 levels in 3 different studies: (1) in CSF and plasma from a case-control study comparing patients with MS (n = 147) with controls (n = 50) and patients with relapsing-remitting MS (n = 75) with patients with progressive MS (n = 72); (2) in CSF and brain tissue microdialysates from a case series of 7 patients with progressive MS; and (3) in CSF at baseline and 60 weeks after natalizumab treatment in a cohort study of 17 patients with progressive MS. Correlation to neurofilament light, a marker of neuroaxonal injury, was tested. The effect of LCN2 on myelination and neurodegeneration was studied in a rat in vitro neuroglial cell coculture model. Results: Intrathecal production of LCN2 was increased predominantly in patients with progressive MS (p < 0.005 vs relapsing-remitting MS) and displayed a positive correlation to neurofilament light (p = 0.005). Levels of LCN2 in brain microdialysates were severalfold higher than in the CSF, suggesting local production in progressive MS. Treatment with natalizumab in progressive MS reduced LCN2 levels an average of 13% (p < 0.0001). LCN2 was found to inhibit remyelination in a dose-dependent manner in vitro. Conclusions: LCN2 production is predominantly increased in progressive MS. Although this moderate increase does not support the use of LCN2 as a biomarker, the correlation to neurofilament light and the inhibitory effect on remyelination suggest that LCN2 might contribute to neurodegeneration through myelination-dependent pathways

Научно-исследовательская, культурно-массовая, физкультурно-спортивная и общественная деятельность студентов как факторы успешности их учебно-познавательного процесса

Материалы IV Респ. науч.-метод. конф., посвящ. 120-летию со дня рождения П. О. Сухого, Гомель, 29–30 окт. 2015 г

Complement Receptor 2 is increased in cerebrospinal fluid of multiple sclerosis patients and regulates C3 function

Besides its vital role in immunity, the complement system also contributes to the shaping of the synaptic circuitry of the brain. We recently described that soluble Complement Receptor 2 (sCR2) is part of the nerve injury response in rodents. We here study CR2 in context of multiple sclerosis (MS) and explore the molecular effects of CR2 on 0 activation. Significant increases in sCR2 levels were evident in cerebrospinal fluid (CSF) from both patients with relapsing remitting MS (n = 33; 6.2 ng/mL) and secondary-progressive MS (n = 9; 7.0 ng/mL) as compared to controls (n = 18; 4.1 ng/mL). Furthermore, CSF sCR2 levels correlated significantly both with CSF C3 and C1q as well as to a disease severity measure. In vitro, sCR2 inhibited the cleavage and down regulation of Cab to iC3b, suggesting that it exerts a modulatory role in complement activation downstream of C3. These results propose a novel function for CR2/sCR2 in human neuroinflammatory conditions

Comparative Assessment of the Prognostic Value of Biomarkers in Traumatic Brain Injury Reveals an Independent Role for Serum Levels of Neurofilament Light

Traumatic brain injury (TBI) is a common cause of death and disability, worldwide. Early determination of injury severity is essential to improve care. Neurofilament light (NF-L) has been introduced as a marker of neuroaxonal injury in neuroinflammatory/-degenerative diseases. In this study we determined the predictive power of serum (s-) and cerebrospinal fluid (CSF-) NF-L levels towards outcome, and explored their potential correlation to diffuse axonal injury (DAI). A total of 182 patients suffering from TBI admitted to the neurointensive care unit at a level 1 trauma center were included. S-NF-L levels were acquired, together with S100B and neuron-specific enolase (NSE). CSF-NF-L was measured in a subcohort (n = 84) with ventriculostomies. Clinical and neuro-radiological parameters, including computerized tomography (CT) and magnetic resonance imaging, were included in the analyses. Outcome was assessed 6 to 12 months after injury using the Glasgow Outcome Score (1-5). In univariate proportional odds analyses mean s-NF-L, -S100B and -NSE levels presented a pseudo-R-2 Nagelkerke of 0.062, 0.214 and 0.074 in correlation to outcome, respectively. In a multivariate analysis, in addition to a model including core parameters (pseudo-R-2 0.33 towards outcome; Age, Glasgow Coma Scale, pupil response, Stockholm CT score, abbreviated injury severity score, S100B), S-NF-L yielded an extra 0.023 pseudo-R-2 and a significantly better model (p = 0.006) No correlation between DAI or CT assessed-intracranial damage and NF-L was found. Our study thus demonstrates that SNF-L correlates to TBI outcome, even if used in models with S100B, indicating an independent contribution to the prediction, perhaps by reflecting different pathophysiological processes, not possible to monitor using conventional neuroradiology. Although we did not find a predictive value of NF-L for DAI, this cannot be completely excluded. We suggest furthe

Identification of gene regions regulating inflammatory microglial response in the rat CNS after nerve injury

Local CNS inflammation takes place in many neurological disorders and is important for autoimmune neuroinflammation. Microglial activation is strain-dependent in rats and differential MHC class II expression is influenced by variations in the Mhc2ta gene. Despite sharing Mhc2ta and MHC class II alleles, BN and LEW.1N rats differ in MHC class II expression after ventral root avulsion (VRA). We studied MHC class II expression and glial activation markers in BN rats after VRA. Our results demonstrate that MHC class II expression originates from a subpopulation of IBA1(+), ED1(-), and ED2(-) microglia. We subsequently performed a genome-wide linkage scan in an F2(BNxLEW.1N) population, to investigate gene regions regulating this inflammatory response. Alongside MHC class II, we studied the expression of MHC class 1, costimulatory molecules, complement components, microglial markers and Il1b. MHC class II and other transcripts were commonly regulated by gene regions on chromosomes 1 and 7. Furthermore, a common region on chromosome 10 regulated expression of complement and co-stimulatory molecules, while a region on chromosome II regulated MHC class I. We also detected epistatic interactions in the regulation of the inflammatory process. These results reveal the complex regulation of CNS inflammation by several gene regions, which may have relevance for disease. (C) 2009 Elsevier B.V. All rights reserved