1
|
Özen I, Clausen F, Flygt J, Marklund N, Paul G. Neutralization of Interleukin 1-beta is associated with preservation of thalamic capillaries after experimental traumatic brain injury. Front Neurol 2024; 15:1378203. [PMID: 38765267 PMCID: PMC11100426 DOI: 10.3389/fneur.2024.1378203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 04/11/2024] [Indexed: 05/21/2024] Open
Abstract
Introduction Traumatic brain injury to thalamo-cortical pathways is associated with posttraumatic morbidity. Diffuse mechanical forces to white matter tracts and deep grey matter regions induce an inflammatory response and vascular damage resulting in progressive neurodegeneration. Pro-inflammatory cytokines, including interleukin-1β (IL-1β), may contribute to the link between inflammation and the injured capillary network after TBI. This study investigates whether IL-1β is a key contributor to capillary alterations and changes in pericyte coverage in the thalamus and cortex after TBI. Methods Animals were subjected to central fluid percussion injury (cFPI), a model of TBI causing widespread axonal and vascular pathology, or sham injury and randomized to receive a neutralizing anti-IL-1β or a control, anti-cyclosporin A antibody, at 30 min post-injury. Capillary length and pericyte coverage of cortex and thalamus were analyzed by immunohistochemistry at 2- and 7-days post-injury. Results and Conclusion Our results show that early post-injury attenuation of IL-1β dependent inflammatory signaling prevents capillary damage by increasing pericyte coverage in the thalamus.
Collapse
Affiliation(s)
- Ilknur Özen
- Lund Brain Injury Laboratory for Neurosurgical Research, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Fredrik Clausen
- Department of Clinical Sciences Lund, Neurosurgery, Lund University, Skåne University Hospital, Lund, Sweden
| | - Johanna Flygt
- Department of Clinical Sciences Lund, Neurosurgery, Lund University, Skåne University Hospital, Lund, Sweden
| | - Niklas Marklund
- Lund Brain Injury Laboratory for Neurosurgical Research, Department of Clinical Sciences, Lund University, Lund, Sweden
- Department of Clinical Sciences Lund, Neurosurgery, Lund University, Skåne University Hospital, Lund, Sweden
| | - Gesine Paul
- Translational Neurology Group, Department of Clinical Science, Wallenberg Neuroscience Center and Wallenberg Center for Molecular Medicine, Lund University, Lund, Sweden
- Department of Neurology, Scania University Hospital, Lund, Sweden
| |
Collapse
|
2
|
Ozen I, Ruscher K, Nilsson R, Flygt J, Clausen F, Marklund N. Interleukin-1 Beta Neutralization Attenuates Traumatic Brain Injury-Induced Microglia Activation and Neuronal Changes in the Globus Pallidus. Int J Mol Sci 2020; 21:ijms21020387. [PMID: 31936248 PMCID: PMC7014296 DOI: 10.3390/ijms21020387] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 12/29/2019] [Accepted: 01/03/2020] [Indexed: 12/14/2022] Open
Abstract
Traumatic brain injury (TBI) increases the risk of delayed neurodegenerative processes, including Parkinson’s disease (PD). Interleukin-1beta (IL-1β), a key pro-inflammatory cytokine, may promote secondary injury development after TBI. Conversely, neutralizing IL-1β was found to improve functional recovery following experimental TBI. However, the mechanisms underlying the behavioral improvements observed by IL-1β neutralization are still poorly understood. The present study investigated the role of IL-1β on the microglia response and neuronal changes in the globus pallidus in response to diffuse TBI. Mice were subjected to sham injury or the central fluid percussion injury (cFPI) (a model of traumatic axonal injury), and were randomly administered an IL-1β neutralizing or a control antibody at 30 min post-injury. The animals were analyzed at 2, 7, or 14 days post-injury. When compared to controls, mice subjected to cFPI TBI had increased microglia activation and dopaminergic innervation in the globus pallidus, and a decreased number of parvalbumin (PV) positive interneurons in the globus pallidus. Neutralization of IL-1β attenuated the microglia activation, prevented the loss of PV+ interneurons and normalized dopaminergic fiber density in the globus pallidus of brain-injured animals. These findings argue for an important role for neuro-inflammation in the PD-like pathology observed in TBI.
Collapse
Affiliation(s)
- Ilknur Ozen
- Lund Brain Injury Laboratory for Neurosurgical Research, Department of Clinical Sciences, Lund University, 22184 Lund, Sweden; (I.O.); (K.R.); (R.N.)
| | - Karsten Ruscher
- Lund Brain Injury Laboratory for Neurosurgical Research, Department of Clinical Sciences, Lund University, 22184 Lund, Sweden; (I.O.); (K.R.); (R.N.)
- Laboratory for Experimental Brain Research, Department of Clinical Sciences, Lund University, 22184 Lund, Sweden
| | - Robert Nilsson
- Lund Brain Injury Laboratory for Neurosurgical Research, Department of Clinical Sciences, Lund University, 22184 Lund, Sweden; (I.O.); (K.R.); (R.N.)
- Laboratory for Experimental Brain Research, Department of Clinical Sciences, Lund University, 22184 Lund, Sweden
| | - Johanna Flygt
- Department of Neuroscience, Section of Neurosurgery, Uppsala University, 75185 Uppsala, Sweden; (J.F.); (F.C.)
| | - Fredrik Clausen
- Department of Neuroscience, Section of Neurosurgery, Uppsala University, 75185 Uppsala, Sweden; (J.F.); (F.C.)
| | - Niklas Marklund
- Lund Brain Injury Laboratory for Neurosurgical Research, Department of Clinical Sciences, Lund University, 22184 Lund, Sweden; (I.O.); (K.R.); (R.N.)
- Department of Neuroscience, Section of Neurosurgery, Uppsala University, 75185 Uppsala, Sweden; (J.F.); (F.C.)
- Department of Clinical Sciences Lund, Neurosurgery, Lund University, 22185 Lund, Sweden
- Correspondence:
| |
Collapse
|
3
|
Flygt J, Ruscher K, Norberg A, Mir A, Gram H, Clausen F, Marklund N. Neutralization of Interleukin-1β following Diffuse Traumatic Brain Injury in the Mouse Attenuates the Loss of Mature Oligodendrocytes. J Neurotrauma 2018; 35:2837-2849. [PMID: 29690837 PMCID: PMC6247990 DOI: 10.1089/neu.2018.5660] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Traumatic brain injury (TBI) commonly results in injury to the components of the white matter tracts, causing post-injury cognitive deficits. The myelin-producing oligodendrocytes (OLs) are vulnerable to TBI, although may potentially be replaced by proliferating oligodendrocyte progenitor cells (OPCs). The cytokine interleukin-1β (IL-1β) is a key mediator of the complex inflammatory response, and when neutralized in experimental TBI, behavioral outcome was improved. To evaluate the role of IL-1β on oligodendrocyte cell death and OPC proliferation, 116 adult male mice subjected to sham injury or the central fluid percussion injury (cFPI) model of traumatic axonal injury, were analyzed at two, seven, and 14 days post-injury. At 30 min post-injury, mice were randomly administered an IL-1β neutralizing or a control antibody. OPC proliferation (5-ethynyl 2'- deoxyuridine (EdU)/Olig2 co-labeling) and mature oligodendrocyte cell loss was evaluated in injured white matter tracts. Microglia/macrophages immunohistochemistry and ramification using Sholl analysis were also evaluated. Neutralizing IL-1β resulted in attenuated cell death, indicated by cleaved caspase-3 expression, and attenuated loss of mature OLs from two to seven days post-injury in brain-injured animals. IL-1β neutralization also attenuated the early, two day post-injury increase of microglia/macrophage immunoreactivity and altered their ramification. The proliferation of OPCs in brain-injured animals was not altered, however. Our data suggest that IL-1β is involved in the TBI-induced loss of OLs and early microglia/macrophage activation, although not the OPC proliferation. Attenuated oligodendrocyte cell loss may contribute to the improved behavioral outcome observed by IL-1β neutralization in this mouse model of diffuse TBI.
Collapse
Affiliation(s)
- Johanna Flygt
- 1 Department of Neuroscience, Section of Neurosurgery, Uppsala University , Uppsala, Sweden
| | - Karsten Ruscher
- 2 Novartis Institutes of Biomedical Research , Basel, Switzerland
| | - Amanda Norberg
- 1 Department of Neuroscience, Section of Neurosurgery, Uppsala University , Uppsala, Sweden
| | - Anis Mir
- 3 Lund University, Skane University Hospital , Department of Clinical Sciences Lund, Neurosurgery, Lund, Sweden
| | - Hermann Gram
- 3 Lund University, Skane University Hospital , Department of Clinical Sciences Lund, Neurosurgery, Lund, Sweden
| | - Fredrik Clausen
- 1 Department of Neuroscience, Section of Neurosurgery, Uppsala University , Uppsala, Sweden
| | - Niklas Marklund
- 1 Department of Neuroscience, Section of Neurosurgery, Uppsala University , Uppsala, Sweden .,3 Lund University, Skane University Hospital , Department of Clinical Sciences Lund, Neurosurgery, Lund, Sweden
| |
Collapse
|
4
|
Flygt J, Clausen F, Marklund N. Diffuse traumatic brain injury in the mouse induces a transient proliferation of oligodendrocyte progenitor cells in injured white matter tracts. Restor Neurol Neurosci 2018; 35:251-263. [PMID: 27768001 DOI: 10.3233/rnn-160675] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Injury to the white matter may lead to impaired neuronal signaling and is commonly observed following traumatic brain injury (TBI). Although endogenous repair of TBI-induced white matter pathology is limited, oligodendrocyte progenitor cells (OPCs) may be stimulated to proliferate and regenerate functionally myelinating oligodendrocytes. Even though OPCs are present throughout the adult brain, little is known about their proliferative activity following axonal injury caused by TBI. OBJECTIVE We hypothesized that central fluid percussion injury (cFPI) in mice, a TBI model causing wide-spread axonal injury, results in OPC proliferation. METHODS Proliferation of OPCs was evaluated in 27 cFPI mice using 5-ethynyl-2'-deoxyuridine (EdU) labeling and a cell proliferation assay at 2 (n = 9), 7 (n = 8) and 21 (n = 10) days post injury (dpi). Sham-injured mice (n = 14) were used as controls. OPC proliferation was quantified by immunohistochemistry using the OPC markers NG2 and Olig2 in several white matter loci including the corpus callosum, external capsule, fimbriae, the internal capsule and cerebral peduncle. RESULTS The number of EdU/DAPI/Olig2-positive cells were increased in the cFPI group compared to sham-injured animals at 7 days post-injury (dpi; p≤0.05) in the majority of white matter regions. The OPC proliferation had subsided by 21 dpi. The number of EdU/DAPI/NG2 cells was also increase at 7 dpi in the external capsule and fimbriae. CONCLUSION These results suggest that traumatic axonal injury in the mouse induces a transient proliferative response of residing OPCs. These proliferating OPCs may replace dead oligodendrocytes and contribute to remyelination, which needs evaluation in future studies.
Collapse
|
5
|
Flygt J, Gumucio A, Ingelsson M, Skoglund K, Holm J, Alafuzoff I, Marklund N. Human Traumatic Brain Injury Results in Oligodendrocyte Death and Increases the Number of Oligodendrocyte Progenitor Cells. J Neuropathol Exp Neurol 2016; 75:503-15. [PMID: 27105664 DOI: 10.1093/jnen/nlw025] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 02/28/2016] [Indexed: 12/13/2022] Open
Abstract
Oligodendrocyte (OL) death may contribute to white matter pathology, a common cause of network dysfunction and persistent cognitive problems in patients with traumatic brain injury (TBI). Oligodendrocyte progenitor cells (OPCs) persist throughout the adult CNS and may replace dead OLs. OL death and OPCs were analyzed by immunohistochemistry of human brain tissue samples, surgically removed due to life-threatening contusions and/or focal brain swelling at 60.6 ± 75 hours (range 4-192 hours) postinjury in 10 severe TBI patients (age 51.7 ± 18.5 years). Control brain tissue was obtained postmortem from 5 age-matched patients without CNS disorders. TUNEL and CC1 co-labeling was used to analyze apoptotic OLs, which were increased in injured brain tissue (p < 0.05), without correlation with time from injury until surgery. The OPC markers Olig2, A2B5, NG2, and PDGFR-α were used. In contrast to the number of single-labeled Olig2, A2B5, NG2, and PDGFR-α-positive cells, numbers of Olig2 and A2B5 co-labeled cells were increased in TBI samples (p < 0.05); this was inversely correlated with time from injury to surgery (r = -0.8, p < 0.05). These results indicate that severe focal human TBI results in OL death and increases in OPCs postinjury, which may influence white matter function following TBI.
Collapse
Affiliation(s)
- Johanna Flygt
- From the Department of Neuroscience, Neurosurgery (JF, KS, JH, NM), and Department of Public Health and Caring Sciences, Geriatrics (AG, MI), and Department of Immunology, Genetics and Pathology (IA), Uppsala University, Uppsala, Sweden
| | - Astrid Gumucio
- From the Department of Neuroscience, Neurosurgery (JF, KS, JH, NM), and Department of Public Health and Caring Sciences, Geriatrics (AG, MI), and Department of Immunology, Genetics and Pathology (IA), Uppsala University, Uppsala, Sweden
| | - Martin Ingelsson
- From the Department of Neuroscience, Neurosurgery (JF, KS, JH, NM), and Department of Public Health and Caring Sciences, Geriatrics (AG, MI), and Department of Immunology, Genetics and Pathology (IA), Uppsala University, Uppsala, Sweden
| | - Karin Skoglund
- From the Department of Neuroscience, Neurosurgery (JF, KS, JH, NM), and Department of Public Health and Caring Sciences, Geriatrics (AG, MI), and Department of Immunology, Genetics and Pathology (IA), Uppsala University, Uppsala, Sweden
| | - Jonatan Holm
- From the Department of Neuroscience, Neurosurgery (JF, KS, JH, NM), and Department of Public Health and Caring Sciences, Geriatrics (AG, MI), and Department of Immunology, Genetics and Pathology (IA), Uppsala University, Uppsala, Sweden
| | - Irina Alafuzoff
- From the Department of Neuroscience, Neurosurgery (JF, KS, JH, NM), and Department of Public Health and Caring Sciences, Geriatrics (AG, MI), and Department of Immunology, Genetics and Pathology (IA), Uppsala University, Uppsala, Sweden
| | - Niklas Marklund
- From the Department of Neuroscience, Neurosurgery (JF, KS, JH, NM), and Department of Public Health and Caring Sciences, Geriatrics (AG, MI), and Department of Immunology, Genetics and Pathology (IA), Uppsala University, Uppsala, Sweden.
| |
Collapse
|
6
|
Ekmark-Lewén S, Flygt J, Fridgeirsdottir GA, Kiwanuka O, Hånell A, Meyerson BJ, Mir AK, Gram H, Lewén A, Clausen F, Hillered L, Marklund N. Diffuse traumatic axonal injury in mice induces complex behavioural alterations that are normalized by neutralization of interleukin-1β. Eur J Neurosci 2016; 43:1016-33. [PMID: 27091435 DOI: 10.1111/ejn.13190] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 01/06/2016] [Accepted: 01/26/2016] [Indexed: 12/15/2022]
Abstract
Widespread traumatic axonal injury (TAI) results in brain network dysfunction, which commonly leads to persisting cognitive and behavioural impairments following traumatic brain injury (TBI). TBI induces a complex neuroinflammatory response, frequently located at sites of axonal pathology. The role of the pro-inflammatory cytokine interleukin (IL)-1β has not been established in TAI. An IL-1β-neutralizing or a control antibody was administered intraperitoneally at 30 min following central fluid percussion injury (cFPI), a mouse model of widespread TAI. Mice subjected to moderate cFPI (n = 41) were compared with sham-injured controls (n = 20) and untreated, naive mice (n = 9). The anti-IL-1β antibody reached the target brain regions in adequate therapeutic concentrations (up to ~30 μg/brain tissue) at 24 h post-injury in both cFPI (n = 5) and sham-injured (n = 3) mice, with lower concentrations at 72 h post-injury (up to ~18 μg/g brain tissue in three cFPI mice). Functional outcome was analysed with the multivariate concentric square field (MCSF) test at 2 and 9 days post-injury, and the Morris water maze (MWM) at 14-21 days post-injury. Following TAI, the IL-1β-neutralizing antibody resulted in an improved behavioural outcome, including normalized behavioural profiles in the MCSF test. The performance in the MWM probe (memory) trial was improved, although not in the learning trials. The IL-1β-neutralizing treatment did not influence cerebral ventricle size or the number of microglia/macrophages. These findings support the hypothesis that IL-1β is an important contributor to the processes causing complex cognitive and behavioural disturbances following TAI.
Collapse
Affiliation(s)
- Sara Ekmark-Lewén
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala, Sweden
| | - Johanna Flygt
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala, Sweden
| | | | - Olivia Kiwanuka
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala, Sweden
| | - Anders Hånell
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala, Sweden
| | - Bengt J Meyerson
- Department of Neuroscience, Pharmacology, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | - Anis K Mir
- Novartis Institutes of Biomedical Research, Basel, Switzerland
| | - Hermann Gram
- Novartis Institutes of Biomedical Research, Basel, Switzerland
| | - Anders Lewén
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala, Sweden
| | - Fredrik Clausen
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala, Sweden
| | - Lars Hillered
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala, Sweden
| | - Niklas Marklund
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala, Sweden.,Department of Neurosurgery, Uppsala University Hospital, Ing 85, 2 tr, SE-756 55, Uppsala, Sweden
| |
Collapse
|
7
|
Israelsson C, Flygt J, Åstrand E, Kiwanuka O, Bengtsson H, Marklund N. Altered expression of myelin-associated inhibitors and their receptors after traumatic brain injury in the mouse. Restor Neurol Neurosci 2015; 32:717-31. [PMID: 25079982 DOI: 10.3233/rnn-140419] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE When central nervous system axons are injured, regeneration is partly inhibited by myelin-associated inhibitors (MAIs). Following traumatic brain injury (TBI) in the rat, pharmacological neutralisation of the MAIs Nogo-A and myelin-associated glycoprotein (MAG) resulted in improved functional outcome. In contrast, genetic or pharmacological neutralization of the MAI receptors Nogo-66 receptor 1 (NgR1) or paired-immunoglobulin like receptor-B (PirB) showed an unaltered or impaired outcome following TBI in mice. The aim of the present study was thus to evaluate the MAI expression levels following TBI in mice. METHODS Quantitative reverse transcriptase PCR (qRT-PCR) was used to measure total RNA isolated from brains of young adult male C57BL/6 mice at one, three or seven days following controlled cortical impact TBI or sham injury. Hippocampal and neocortical tissue ipsi- and contralateral to the injury was analyzed for Nogo-A, oligodendrocyte-myelin glycoprotein (OMgp), MAG, and the MAI receptors PirB and NgR1, including its co-receptor Lingo1. RESULTS Compared to sham-injured controls, PirB neocortical expression was significantly upregulated at one day and NgR1 expression downregulated at seven days post-TBI. In the hippocampus, transcriptional upregulation was observed in Nogo-A (one day post-injury), MAG and PirB at seven days post-injury. In contrast, the hippocampal transcripts of NgR1 and Lingo1 were decreased at seven days post-injury. The expression of OMgp was unaltered at all time points post-injury. CONCLUSION These results suggest that early dynamic changes in MAI gene expression occur following TBI in the mouse, particularly in the hippocampus, which may play an inhibitory role for post-injury regeneration and plasticity.
Collapse
Affiliation(s)
- Charlotte Israelsson
- Department of Neuroscience, Developmental Neuroscience, Uppsala University, Uppsala, Sweden
| | - Johanna Flygt
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala, Sweden
| | - Elaine Åstrand
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala, Sweden
| | - Olivia Kiwanuka
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala, Sweden
| | - Henrik Bengtsson
- Department of Neuroscience, Developmental Neuroscience, Uppsala University, Uppsala, Sweden
| | - Niklas Marklund
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala, Sweden
| |
Collapse
|
8
|
Skoglund K, Hillered L, Purins K, Tsitsopoulos PP, Flygt J, Engquist H, Lewén A, Enblad P, Marklund N. The neurological wake-up test does not alter cerebral energy metabolism and oxygenation in patients with severe traumatic brain injury. Neurocrit Care 2015; 20:413-26. [PMID: 23934408 DOI: 10.1007/s12028-013-9876-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND The neurological wake-up test (NWT) is used to monitor the level of consciousness in patients with traumatic brain injury (TBI). However, it requires interruption of sedation and may elicit a stress response. We evaluated the effects of the NWT using cerebral microdialysis (MD), brain tissue oxygenation (PbtiO2), jugular venous oxygen saturation (SjvO2), and/or arterial-venous difference (AVD) for glucose, lactate, and oxygen in patients with severe TBI. METHODS Seventeen intubated TBI patients (age 16-74 years) were sedated using continuous propofol infusion. All patients received intracranial pressure (ICP) and cerebral perfusion pressure (CPP) monitoring in addition to MD, PbtiO2 and/or SjvO2. Up to 10 days post-injury, ICP, CPP, PbtiO2 (51 NWTs), MD (49 NWTs), and/or SjvO2 (18 NWTs) levels during propofol sedation (baseline) and NWT were compared. MD was evaluated at a flow rate of 1.0 μL/min (28 NWTs) or the routine 0.3 μL/min rate (21 NWTs). RESULTS The NWT increased ICP and CPP levels (p < 0.05). Compared to baseline, interstitial levels of glucose, lactate, pyruvate, glutamate, glycerol, and the lactate/pyruvate ratio were unaltered by the NWT. Pathological SjvO2 (<50 % or >71 %; n = 2 NWTs) and PbtiO2 (<10 mmHg; n = 3 NWTs) values were rare at baseline and did not change following NWT. Finally, the NWT did not alter the AVD of glucose, lactate, or oxygen. CONCLUSIONS The NWT-induced stress response resulted in increased ICP and CPP levels although it did not negatively alter focal neurochemistry or cerebral oxygenation in TBI patients.
Collapse
Affiliation(s)
- Karin Skoglund
- Department of Neuroscience, Neurosurgery, Uppsala University Hospital, Uppsala University, 75185, Uppsala, Sweden
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Axelson HW, Winkler T, Flygt J, Djupsjö A, Hånell A, Marklund N. Plasticity of the contralateral motor cortex following focal traumatic brain injury in the rat. Restor Neurol Neurosci 2013; 31:73-85. [PMID: 23047494 DOI: 10.3233/rnn-2012-120242] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE Recovery is limited following traumatic brain injury (TBI) since injured axons regenerate poorly and replacement of lost cells is minimal. Behavioral improvements could instead be due to plasticity of uninjured brain regions. We hypothesized that plasticity of the uninjured hemisphere occurs contralateral to a focal TBI in the adult rat. Thus, we performed cortical mapping of the cortex contralateral to the TBI using intracortical microstimulation (ICMS). METHODS A focal TBI was induced using the weight-drop technique (n = 5) and sham-injured animals were used as controls (n = 4). At five weeks post-injury, ICMS was used to map the motor area contralateral to the injury. Motor responses were detected by visual inspection and electromyography (EMG). RESULTS In sham- and brain-injured animals, numerous fore- and hindlimb motor responses contralateral to the stimulation (ipsilateral to the injury) were obtained. Compared to sham-injured controls, there was a markedly increased (p < 0.05) number of fore- and hindlimb responses ipsilateral to the stimulation after TBI. CONCLUSION Following focal TBI in the rat, our data suggest reorganization of cortical and/or subcortical regions in the uninjured hemisphere contralateral to a focal TBI leading to an altered responsiveness to ICMS. Although we cannot exclude that these changes are maladaptive, it is plausible that this plasticity process positively influences motor recovery after TBI.
Collapse
Affiliation(s)
- Hans W Axelson
- Department of Neuroscience, Neurophysiology, Uppsala University, Uppsala, Sweden
| | | | | | | | | | | |
Collapse
|
10
|
Ekmark-Lewén S, Flygt J, Kiwanuka O, Meyerson BJ, Lewén A, Hillered L, Marklund N. Traumatic axonal injury in the mouse is accompanied by a dynamic inflammatory response, astroglial reactivity and complex behavioral changes. J Neuroinflammation 2013; 10:44. [PMID: 23557178 PMCID: PMC3651302 DOI: 10.1186/1742-2094-10-44] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 03/07/2013] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Diffuse traumatic axonal injury (TAI), a common consequence of traumatic brain injury, is associated with high morbidity and mortality. Inflammatory processes may play an important role in the pathophysiology of TAI. In the central fluid percussion injury (cFPI) TAI model in mice, the neuroinflammatory and astroglial response and behavioral changes are unknown. METHODS Twenty cFPI-injured and nine sham-injured mice were used, and the neuroinflammatory and astroglial response was evaluated by immunohistochemistry at 1, 3 and 7 days post-injury. The multivariate concentric square field test (MCSF) was used to compare complex behavioral changes in mice subjected to cFPI (n = 16) or sham injury (n = 10). Data was analyzed using non-parametric statistics and principal component analysis (MCSF data). RESULTS At all post-injury time points, β-amyloid precursor protein (β-APP) immunoreactivity revealed widespread bilateral axonal injury and IgG immunostaining showed increased blood-brain barrier permeability. Using vimentin and glial fibrillary acidic protein (GFAP) immunohistochemistry, glial cell reactivity was observed in cortical regions and important white matter tracts peaking at three days post-injury. Only vimentin was increased post-injury in the internal capsule and only GFAP in the thalamus. Compared to sham-injured controls, an increased number of activated microglia (MAC-2), infiltrating neutrophils (GR-1) and T-cells (CD3) appearing one day after TAI (P<0.05 for all cell types) was observed in subcortical white matter. In the MCSF, the behavioral patterns including general activity and exploratory behavior differed between cFPI mice and sham-injured controls. CONCLUSIONS Traumatic axonal injury TAI resulted in marked bilateral astroglial and neuroinflammatory responses and complex behavioral changes. The cFPI model in mice appears suitable for the study of injury mechanisms, including neuroinflammation, and the development of treatments targeting TAI.
Collapse
Affiliation(s)
- Sara Ekmark-Lewén
- Department of Neuroscience, Division of Neurosurgery, Uppsala University, Uppsala, 751 85, Sweden
| | - Johanna Flygt
- Department of Neuroscience, Division of Neurosurgery, Uppsala University, Uppsala, 751 85, Sweden
| | - Olivia Kiwanuka
- Department of Neuroscience, Division of Neurosurgery, Uppsala University, Uppsala, 751 85, Sweden
| | - Bengt J Meyerson
- Department of Neuroscience, Division of Pharmacology, Biomedical Center, Uppsala University, Uppsala, 715 23, Sweden
| | - Anders Lewén
- Department of Neuroscience, Division of Neurosurgery, Uppsala University, Uppsala, 751 85, Sweden
| | - Lars Hillered
- Department of Neuroscience, Division of Neurosurgery, Uppsala University, Uppsala, 751 85, Sweden
| | - Niklas Marklund
- Department of Neuroscience, Division of Neurosurgery, Uppsala University, Uppsala, 751 85, Sweden
| |
Collapse
|
11
|
Flygt J, Djupsjö A, Lenne F, Marklund N. Myelin loss and oligodendrocyte pathology in white matter tracts following traumatic brain injury in the rat. Eur J Neurosci 2013; 38:2153-65. [PMID: 23458840 DOI: 10.1111/ejn.12179] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 01/29/2013] [Accepted: 02/05/2013] [Indexed: 12/11/2022]
Abstract
Axonal injury is an important contributor to the behavioral deficits observed following traumatic brain injury (TBI). Additionally, loss of myelin and/or oligodendrocytes can negatively influence signal transduction and axon integrity. Apoptotic oligodendrocytes, changes in the oligodendrocyte progenitor cell (OPC) population and loss of myelin were evaluated at 2, 7 and 21 days following TBI. We used the central fluid percussion injury model (n = 18 and three controls) and the lateral fluid percussion injury model (n = 15 and three controls). The external capsule, fimbriae and corpus callosum were analysed. With Luxol Fast Blue and RIP staining, myelin loss was observed in both models, in all evaluated regions and at all post-injury time points, as compared with sham-injured controls (P ≤ 0.05). Accumulation of β-amyloid precursor protein was observed in white matter tracts in both models in areas with preserved and reduced myelin staining. White matter microglial/macrophage activation, evaluated by isolectin B4 immunostaining, was marked at the early time points. In contrast, the glial scar, evaluated by glial fibrillary acidic protein staining, showed its highest intensity 21 days post-injury in both models. The number of apoptotic oligodendrocytes, detected by CC1/caspase-3 co-labeling, was increased in both models in all evaluated regions. Finally, the numbers of OPCs, evaluated with the markers Tcf4 and Olig2, were increased from day 2 (Olig2) or day 7 (Tcf4) post-injury (P ≤ 0.05). Our results indicate that TBI induces oligodendrocyte apoptosis and widespread myelin loss, followed by a concomitant increase in the number of OPCs. Prevention of myelin loss and oligodendrocyte death may represent novel therapeutic targets for TBI.
Collapse
Affiliation(s)
- J Flygt
- Department of Neurosurgery, Uppsala University Hospital, Uppsala SE-751 85, Sweden
| | | | | | | |
Collapse
|