| 1. |
- Olsson, Sandra, 1976, et al.
(author)
-
Genetic variation in complement component C3 shows association with ischaemic stroke.
- 2011
-
In: European journal of neurology : the official journal of the European Federation of Neurological Societies. - : Wiley. - 1468-1331. ; 42, s. 214-16
-
Journal article (peer-reviewed)abstract
- Background and purpose: The aim of this study was to investigate whether genetic variation at the third complement component (C3) locus is associated with ischaemic stroke (IS). Methods: The Sahlgrenska Academy Study on Ischaemic Stroke comprises 844 patients with IS, and 668 healthy controls. Sixteen SNPs were analyzed. Results: Two SNPs, rs2277984 and rs3745565, showed a significant association with overall IS. The SNP rs2277984 also showed association with the IS subtype cryptogenic stroke. These associations were independent of hypertension, diabetes, and smoking. The independent association between rs3745565 and overall IS withstands correction for multiple testing. Conclusion: In this sample of patients with IS, genetic variation in C3 is associated with IS.
|
|
| 2. |
- Stokowska, Anna, et al.
(author)
-
Cardioembolic and Small Vessel Disease Stroke Show Differences in Associations between Systemic C3 Levels and Outcome
- 2013
-
In: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 8:8
-
Journal article (peer-reviewed)abstract
- Background: Activation of the complement system has been proposed to play a role in the pathophysiology of stroke. As the specific involvement of the complement proteins may be influenced by stroke etiology, we compared plasma C3 and C3a levels in patients with cardioembolic (CE) and small vessel disease (SVD) subtypes of ischemic stroke and control subjects and evaluated their association to outcome at three months and two years. Methodology/Principal Findings: Plasma C3 and C3a levels in 79 CE and 79 SVD stroke patients, sampled within 10 days and at three months after stroke, and age- and sex-matched control subjects from The Sahlgrenska Academy Study on Ischemic Stroke were measured by ELISA. Functional outcome was assesed with modified Rankin Scale. In the CE group, plasma C3 levels were elevated only in the acute phase, whereas C3a was elevated at both time points. The follow-up phase plasma C3 levels in the upper third were associated with an increased risk of unfavorable outcome at three months (OR 7.12, CI 1.72-29.46, P = 0.007) as well as after two years (OR 8.25, CI 1.61-42.28, P = 0.011) after stroke. These associations withstand adjustment for age and sex. Conversely, three-month follow-up plasma C3a/C3 level ratios in the middle third were associated with favorable outcome after two years both in the univariate analysis (OR 0.19, CI 0.05-0.82, P = 0.026) and after adjustment for age and sex (OR 0.19, CI 0.04-0.88, P = 0.033). In the SVD group, plasma C3 and C3a levels were elevated at both time points but showed no significant associations with outcome. Conclusions: Plasma C3 and C3a levels are elevated after CE and SVD stroke but show associations with outcome only in CE stroke.
|
|
| 3. |
- Stokowska, Anna, et al.
(author)
-
Plasma c3 and c3a levels in cryptogenic and large-vessel disease stroke: associations with outcome.
- 2011
-
In: Cerebrovascular diseases (Basel, Switzerland). - : S. Karger AG. - 1421-9786 .- 1015-9770. ; 32:2, s. 114-22
-
Journal article (peer-reviewed)abstract
- Background and Purpose: Inflammation seems to be a key player in the pathophysiology of stroke. In this study, we compared plasma C3 and C3a levels in cryptogenic and large-vessel disease (LVD) subtypes of ischemic stroke and control subjects and evaluated their association to outcome at 3 months and 2 years. Methods: C3 and C3a levels in plasma of 79 cryptogenic stroke and 73 LVD stroke patients, sampled within 10 days and at 3 months after stroke, and age- and sex-matched control subjects from the Sahlgrenska Academy Study on Ischemic Stroke were measured by ELISA. Functional outcome was assessed with the modified Rankin Scale. Results: Plasma C3 was increased in both stroke groups at both time points. Systemic elevation of C3a was limited to the acute phase in the cryptogenic stroke group, whereas plasma C3a levels in the LVD group were also elevated at the 3-month follow-up. In the LVD group, plasma C3 levels in the upper third at the 3-month follow-up were associated with an unfavorable outcome after 3 months independently of age and sex: odds ratio (OR) 5.56; 95% confidence interval (CI) 1.03-29.93; p = 0.045; as well as after 2 years: OR 4.75; 95% CI 1.11-20.30; p = 0.036. In the cryptogenic stroke group, high plasma C3a levels in the acute phase were associated with an unfavorable outcome after 3 months: OR 3.75; 95% CI 1.01-13.96; p = 0.049 in univariate analysis but not after adjustment for age and sex (p = 0.050). Conclusions: Plasma C3 and C3a levels are elevated in cryptogenic and LVD stroke and the predictive value of these markers may depend on stroke subtype. Further studies on the role of the complement system in ischemic stroke outcome based on larger patient populations and controlling for the effect of infections, are clearly warranted.
|
|
| 4. |
- Andersson, Daniel, 1979, et al.
(author)
-
Plasticity Response in the Contralesional Hemisphere after Subtle Neurotrauma: Gene Expression Profiling after Partial Deafferentation of the Hippocampus
- 2013
-
In: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 8:7
-
Journal article (peer-reviewed)abstract
- Neurotrauma or focal brain ischemia are known to trigger molecular and structural responses in the uninjured hemisphere. These responses may have implications for tissue repair processes as well as for the recovery of function. To determine whether the plasticity response in the uninjured hemisphere occurs even after a subtle trauma, we subjected mice to a partial unilateral deafferentation of the hippocampus induced by stereotactically performed entorhinal cortex lesion (ECL). The expression of selected genes was assessed by quantitative real-time PCR in the hippocampal tissue at the injured side and the contralesional side at day 4 and 14 after injury. We observed that expression of genes coding for synaptotagmin 1, ezrin, thrombospondin 4, and C1q proteins, that have all been implicated in the synapse formation, re-arrangement and plasticity, were upregulated both in the injured and the contralesional hippocampus, implying a plasticity response in the uninjured hemisphere. Several of the genes, the expression of which was altered in response to ECL, are known to be expressed in astrocytes. To test whether astrocyte activation plays a role in the observed plasticity response to ECL, we took advantage of mice deficient in two intermediate filament (nanofilament) proteins glial fibrillary acidic protein (GFAP) and vimentin (GFAP(-/-) Vim(-/-)) and exhibiting attenuated astrocyte activation and reactive gliosis. The absence of GFAP and vimentin reduced the ECL-induced upregulation of thrombospondin 4, indicating that this response to ECL depends on astrocyte activation and reactive gliosis. We conclude that even a very limited focal neurotrauma triggers a distinct response at the contralesional side, which at least to some extent depends on astrocyte activation.
|
|
| 5. |
- Andersson, Karin, 1972, et al.
(author)
-
Inflammation in the hippocampus affects IGF1 receptor signaling and contributes to neurological sequelae in rheumatoid arthritis.
- 2018
-
In: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 1091-6490. ; 115:51, s. E12063-E12072
-
Journal article (peer-reviewed)abstract
- Rheumatoid arthritis (RA) is an inflammatory joint disease with a neurological component including depression, cognitive deficits, and pain, which substantially affect patients' quality of daily life. Insulin-like growth factor 1 receptor (IGF1R) signaling is one of the factors in RA pathogenesis as well as a known regulator of adult neurogenesis. The purpose of this study was to investigate the association between IGF1R signaling and the neurological symptoms in RA. In experimental RA, we demonstrated that arthritis induced enrichment of IBA1+ microglia in the hippocampus. This coincided with inhibitory phosphorylation of insulin receptor substrate 1 (IRS1) and up-regulation of IGF1R in the pyramidal cell layer of the cornus ammoni and in the dentate gyrus, reproducing the molecular features of the IGF1/insulin resistance. The aberrant IGF1R signaling was associated with reduced hippocampal neurogenesis, smaller hippocampus, and increased immobility of RA mice. Inhibition of IGF1R in experimental RA led to a reduction of IRS1 inhibition and partial improvement of neurogenesis. Evaluation of physical functioning and brain imaging in RA patients revealed that enhanced functional disability is linked with smaller hippocampus volume and aberrant IGF1R/IRS1 signaling. These results point to abnormal IGF1R signaling in the brain as a mediator of neurological sequelae in RA and provide support for the potentially reversible nature of hippocampal changes.
|
|
| 6. |
- Aswendt, M., et al.
(author)
-
Reactive astrocytes prevent maladaptive plasticity after ischemic stroke
- 2022
-
In: Progress in Neurobiology. - : Elsevier BV. - 0301-0082. ; 209
-
Journal article (peer-reviewed)abstract
- Restoration of functional connectivity is a major contributor to functional recovery after stroke. We investigated the role of reactive astrocytes in functional connectivity and recovery after photothrombotic stroke in mice with attenuated reactive gliosis (GFAP–/–Vim–/–). Infarct volume and longitudinal functional connectivity changes were determined by in vivo T2-weighted magnetic resonance imaging (MRI) and resting-state functional MRI. Sensorimotor function was assessed with behavioral tests, and glial and neural plasticity responses were quantified in the peri-infarct region. Four weeks after stroke, GFAP–/–Vim–/– mice showed impaired recovery of sensorimotor function and aberrant restoration of global neuronal connectivity. These mice also exhibited maladaptive plasticity responses, shown by higher number of lost and newly formed functional connections between primary and secondary targets of cortical stroke regions and increased peri-infarct expression of the axonal plasticity marker Gap43. We conclude that reactive astrocytes modulate recovery-promoting plasticity responses after ischemic stroke. © 2021
|
|
| 7. |
- Berg, Alexander, et al.
(author)
-
Axonal Regeneration after Sciatic Nerve Lesion Is Delayed but Complete in GFAP- and Vimentin-Deficient Mice.
- 2013
-
In: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 8:11
-
Journal article (peer-reviewed)abstract
- Peripheral axotomy of motoneurons triggers Wallerian degeneration of injured axons distal to the lesion, followed by axon regeneration. Centrally, axotomy induces loss of synapses (synaptic stripping) from the surface of lesioned motoneurons in the spinal cord. At the lesion site, reactive Schwann cells provide trophic support and guidance for outgrowing axons. The mechanisms of synaptic stripping remain elusive, but reactive astrocytes and microglia appear to be important in this process. We studied axonal regeneration and synaptic stripping of motoneurons after a sciatic nerve lesion in mice lacking the intermediate filament (nanofilament) proteins glial fibrillary acidic protein (GFAP) and vimentin, which are upregulated in reactive astrocytes and Schwann cells. Seven days after sciatic nerve transection, ultrastructural analysis of synaptic density on the somata of injured motoneurons revealed more remaining boutons covering injured somata in GFAP(-/-)Vim(-/-) mice. After sciatic nerve crush in GFAP(-/-)Vim(-/-) mice, the fraction of reinnervated motor endplates on muscle fibers of the gastrocnemius muscle was reduced 13 days after the injury, and axonal regeneration and functional recovery were delayed but complete. Thus, the absence of GFAP and vimentin in glial cells does not seem to affect the outcome after peripheral motoneuron injury but may have an important effect on the response dynamics.
|
|
| 8. |
- Berg, A., et al.
(author)
-
Reduced removal of synaptic terminals from axotomized spinal motoneurons in the absence of complement C3
- 2012
-
In: Experimental Neurology. - : Elsevier BV. - 0014-4886 .- 1090-2430. ; 237:1, s. 8-17
-
Journal article (peer-reviewed)abstract
- Complement proteins C1q and C3 play a critical role in synaptic elimination during development. Axotomy of spinal motoneurons triggers removal of synaptic terminals from the cell surface of motoneurons by largely unknown mechanisms. We therefore hypothesized that the complement system is involved also in synaptic stripping of injured motoneurons. In the sciatic motor pool of wild type (WT) mice, the immunoreactivity (IR) for both C1q and C3 was increased after sciatic nerve transection (SNT). Mice deficient in C3 (C3(-/-)) showed a reduced loss of synaptic terminals from injured motoneurons at one week after SNT, as assessed by immunoreactivity for synaptic markers and electron microscopy. In particular, the removal of putative inhibitory terminals, immunopositive for vesicular inhibitory amino acid transporter (VIAAT) and ultrastructurally identified as type F synapses, was reduced in C3(-/-) mice. In contrast, lesion-induced removal of nerve terminals in C1q(-/-) mice appeared similar to WT mice. Growth associated protein (GAP)-43 mRNA expression in lesioned motoneurons increased much more in C3(-/-) compared to WT mice after SNT. After sciatic nerve crush (SNC), the C3(-/-) mice showed a faster functional recovery, assessed as grip strength, compared to WT mice. No differences were detected regarding nerve inflammation at the site of injury or pattern of muscle reinnervation. These data indicate that a non-classical pathway of complement activation is involved in axotomy-induced adult synapse removal, and that its inhibition promotes functional recovery. (c) 2012 Elsevier Inc. All rights reserved.
|
|
| 9. |
- Bila, Custodio, et al.
(author)
-
Complement opsonization enhances friend virus infection of B cells and thereby amplifies the virus-specific CD8+ T cell response.
- 2011
-
In: Journal of virology. - 1098-5514. ; 85:2, s. 1151-5
-
Journal article (peer-reviewed)abstract
- B cells are one of the targets of Friend virus (FV) infection, a well-established mouse model often used to study retroviral infections in vivo. Although B cells may be effective in stimulating cytotoxic T lymphocyte responses, studies involving their role in FV infection have mainly focused on neutralizing antibody production. Here we show that polyclonal activation of B cells promotes their infection with FV both in vitro and in vivo. Furthermore, we demonstrate that complement opsonization of Friend murine leukemia virus (F-MuLV) enhances infection of B cells, which correlates with increased potency of B cells to activate FV-specific CD8(+) T cells.
|
|
| 10. |
- Bunketorp Käll, Lina, 1975, et al.
(author)
-
Effects of horse-riding therapy and rhythm and music-based therapy on functional mobility in late phase after stroke
- 2019
-
In: Neurorehabilitation. - : IOS Press. - 1053-8135 .- 1878-6448. ; 45:4, s. 483-492
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Persons with stroke commonly have residual neurological deficits that seriously OBJECTIVE: To investigate whether horse-riding therapy (H-RT) and rhythm and music-based therapy METHODS: This study is part of a randomized controlled trial in which H-RT and R-MT was provided RESULTS: 123 participants were assigned to H-RT (n = 41), R-MT (n = 41), or control (n = 41). Post- CONCLUSIONS: The present study supports the efficacy of H-RT in producing immediate gains in gait
|
|
