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- Järlestedt, Katarina, et al.
(författare)
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Receptor for complement peptide C3a: a therapeutic target for neonatal hypoxic-ischemic brain injury.
- 2013
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Ingår i: FASEB journal : official publication of the Federation of American Societies for Experimental Biology. - Bethesda : Wiley. - 1530-6860 .- 0892-6638. ; 27:9, s. 3797-3804
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Tidskriftsartikel (refereegranskat)abstract
- Complement is an essential component of inflammation that plays a role in ischemic brain injury. Recent reports demonstrate novel functions of complement in normal and diseased CNS, such as regulation of neurogenesis and synapse elimination. Here, we examined the role of complement-derived peptide C3a in unilateral hypoxia-ischemia (HI), a model of neonatal HI encephalopathy. HI injury was induced at postnatal day 9 (P9), and loss of hippocampal tissue was determined on P31. We compared WT mice with transgenic mice expressing C3a under the control of glial fibrillary acidic protein promoter, which express biologically active C3a only in CNS and without the requirement of a priori complement activation. Further, we injected C3a peptide into the lateral cerebral ventricle of mice lacking the C3a receptor (C3aR) and WT mice and assessed HI-induced memory impairment 41 d later. We found that HI-induced tissue loss in C3a overexpressing mice was reduced by 50% compared with WT mice. C3a peptide injected 1 h after HI protected WT but not C3aR-deficient mice against HI-induced memory impairment. Thus, C3a acting through its canonical receptor ameliorates behavioral deficits after HI injury, and C3aR is a novel therapeutic target for the treatment of neonatal HI encephalopathy.-Järlestedt, K., Rousset, C. I., Ståhlberg, A., Sourkova, H., Atkins, A. L., Thornton, C., Barnum, S. R., Wetsel, R. A., Dragunow, M., Pekny, M., Mallard, C., Hagberg, H., Pekna, M. Receptor for complement peptide C3a: a therapeutic target for neonatal hypoxic-ischemic brain injury.
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| 3. |
- Rahpeymai Bogestål, Yalda, 1977, et al.
(författare)
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Signaling through C5aR is not involved in basal neurogenesis.
- 2007
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Ingår i: Journal of neuroscience research. - : Wiley. - 0360-4012 .- 1097-4547. ; 85:13, s. 2892-7
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Tidskriftsartikel (refereegranskat)abstract
- The complement system, an important part of the innate immune system, provides protection against invading pathogens, in part through its proinflammatory activities. Although most complement proteins are synthesized locally in the brain and the relevant complement receptors are expressed on resident brain cells, little is known about brain-specific role(s) of the complement system. C3a and C5a, complement-derived peptides with anaphylatoxic properties, have been implicated in noninflammatory functions, such as tissue regeneration and neuroprotection. Recently, we have shown that signaling through C3a receptor (C3aR) is involved in the regulation of neurogenesis. In the present study, we assessed basal neurogenesis in mice lacking C5a receptor (C5aR(-/-)) and mice expressing C3a and C5a, respectively in the CNS under the control of glial fibrillary acidic protein (GFAP) promoter (C3a/GFAP and C5a/GFAP, respectively) and thus without the requirement for complement activation. We did not observe any difference among C5aR(-/-), C3a/GFAP and C5a/GFAP mice and their respective controls in the number of newly formed neuroblasts and newly formed neurons in the subventricular zone (SVZ) of lateral ventricles and hippocampal dentate gyrus, the two neurogenic niches in the adult brain, or the olfactory bulb, the final destination of new neurons formed in the SVZ. Our results indicate that signaling through C5aR is not involved in basal neurogenesis in adult mice and that basal neurogenesis in adult C3a/GFAP and C5a/GFAP mice is not altered. (c) 2007 Wiley-Liss, Inc.
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- Ramos, Theresa N, et al.
(författare)
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Cutting edge : the membrane attack complex of complement is required for the development of murine experimental cerebral malaria
- 2011
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 186:12, s. 6657-6660
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Tidskriftsartikel (refereegranskat)abstract
- Cerebral malaria is the most severe complication of Plasmodium falciparum infection and accounts for a large number of malaria fatalities worldwide. Recent studies demonstrated that C5(-/-) mice are resistant to experimental cerebral malaria (ECM) and suggested that protection was due to loss of C5a-induced inflammation. Surprisingly, we observed that C5aR(-/-) mice were fully susceptible to disease, indicating that C5a is not required for ECM. C3aR(-/-) and C3aR(-/-) × C5aR(-/-) mice were equally susceptible to ECM as were wild-type mice, indicating that neither complement anaphylatoxin receptor is critical for ECM development. In contrast, C9 deposition in the brains of mice with ECM suggested an important role for the terminal complement pathway. Treatment with anti-C9 Ab significantly increased survival time and reduced mortality in ECM. Our data indicate that protection from ECM in C5(-/-) mice is mediated through inhibition of membrane attack complex formation and not through C5a-induced inflammation.
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| 5. |
- Stokowska, Anna, et al.
(författare)
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Complement peptide C3a stimulates neural plasticity after experimental brain ischaemia.
- 2017
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Ingår i: Brain. - : Oxford University Press. - 0006-8950 .- 1460-2156. ; 140:2
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Tidskriftsartikel (refereegranskat)abstract
- Ischaemic stroke induces endogenous repair processes that include proliferation and differentiation of neural stem cells and extensive rewiring of the remaining neural connections, yet about 50% of stroke survivors live with severe long-term disability. There is an unmet need for drug therapies to improve recovery by promoting brain plasticity in the subacute to chronic phase after ischaemic stroke. We previously showed that complement-derived peptide C3a regulates neural progenitor cell migration and differentiation in vitro and that C3a receptor signalling stimulates neurogenesis in unchallenged adult mice. To determine the role of C3a-C3a receptor signalling in ischaemia-induced neural plasticity, we subjected C3a receptor-deficient mice, GFAP-C3a transgenic mice expressing biologically active C3a in the central nervous system, and their respective wild-type controls to photothrombotic stroke. We found that C3a overexpression increased, whereas C3a receptor deficiency decreased post-stroke expression of GAP43 (P < 0.01), a marker of axonal sprouting and plasticity, in the peri-infarct cortex. To verify the translational potential of these findings, we used a pharmacological approach. Daily intranasal treatment of wild-type mice with C3a beginning 7 days after stroke induction robustly increased synaptic density (P < 0.01) and expression of GAP43 in peri-infarct cortex (P < 0.05). Importantly, the C3a treatment led to faster and more complete recovery of forepaw motor function (P < 0.05). We conclude that C3a-C3a receptor signalling stimulates post-ischaemic neural plasticity and intranasal treatment with C3a receptor agonists is an attractive approach to improve functional recovery after ischaemic brain injury.media-1vid110.1093/brain/aww314_video_abstractaww314_video_abstract.
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