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Investigating the role of cystatin C in experimental autoimmune encephalomyelitis
Abstracts
Results: Blockade of CXCR2 reduced infarct volumes and improved functional outcome in hypercholesterolemic but not in control mice. SB225002 treatment inhibits ischemia-induced increase in peripheral neutrophils, which was associated with a reduced CXCR2 expression and a reduced proportion of viable neutrophils in the bone marrow of ischemic SB225002-treated hypercholesterolemic mice. Neutrophil infiltration into ischemic brains was reduced by CXCR2 blockade in both experimental settings. Conclusion: Whereas SB225002 treatment does not protect the ischemic brain of normocholesterolemic mice, blockade of CXCR2 reduces cerebral tissue injury and improves functional outcome in hypercholesterolemic mice. Interestingly, the neuroprotective effect of SB225002 in hypercholesterolemic mice was associated with an inhibition of ischemia-induced peripheral neutrophilia which might be caused by an increased neutrophil apoptosis in the bone marrow as a result of an increased CXCR2 expression on neutrophils of ischemic hypercholesterolemic mice. Our data demonstrate that pre-clinical and clinical trials should pay more attention to inflammation-associated co-morbidities and particularly emphasize the role of neutrophils in this multifactor associated disease setting.
doi:10.1016/j.jneuroim.2014.08.408
52 Investigating the role of cystatin C in experimental autoimmune encephalomyelitis Vahid Hoghooghia, Shalina S. Ousmanb a
Faculty of Medicine, Department of Neuroscience, University of Calgary, Calgary, Canada; bFaculty of Medicine, Department of Clinical Neurosciences, University of Calgary, Calgary, Canada Multiple sclerosis (MS) is an autoimmune disease characterized by inflammation, demyelination and neurodegeneration of the central nervous system (CNS). The disease is associated with the enhanced and down-regulated expression of scores of genes and proteins but the function of most of these molecules is poorly understood. Cystatin C (CysC) mRNA level is enhanced in the brains of MS subjects and variable amounts of the protein have been found in serum and cerebrospinal fluid of patients. We have also found increased CysC protein expression in the CNS of mice with experimental allergic encephalomyelitis (EAE), an animal model of MS. The function of CysC in MS and EAE however is unclear. CysC is an inhibitor of cysteine proteases including cathepsins B, H, K, L, and S and it is expressed by astrocytes, neurons, microglia and macrophages. Both protective and detrimental effects of CysC have been reported. Due to its decreased expression when macrophages are activated and, its therapeutic effect in collagen-induced arthritis, an anti-inflammatory function for this protease inhibitor has been implied. However, this protease inhibitor has been demonstrated to both prevent cell death and to mediate neurodegeneration. Further, antiCysC promoted the differentiation of oligodendrocyte precursor cells into oligodendrocytes (OLs) suggesting a negative role of this molecule in OL biology. It is therefore unclear what role CysC would play in MS and whether the cell type and environment define its biology. We are investigating the function of CysC in EAE using mice that are null and transgenic for the protein. Our preliminary data shows that CysC has a detrimental role in EAE since it promotes and suppresses clinical disease in CysC overexpressing and knockout mice respectively. Our ongoing studies will dissect whether immunological and/or neurobiological mechanisms underlie the negative effect of CysC in EAE.
153
Supported by a studentship to VH and an operating grant to SSO from the Multiple Sclerosis Society of Canada. doi:10.1016/j.jneuroim.2014.08.409
153 Sodium chloride-high diet promotes pro-inflammatory macrophage activation and aggravates central nervous system autoimmunity Stephanie Hucke, Melanie Eschborn, Annika Engbers, Heinz Wiendl, Luisa Klotz Department of Neurology, University of Muenster, Muenster, Germany It has long been debated whether environmental factors such as nutrition may have an influence on Multiple Sclerosis (MS) incidence and severity. Recently it was shown that a sodium chloride (NaCl)rich diet influences T cell responses during autoimmunity of the central nervous system (CNS) in the animal model of MS, i.e. experimental autoimmune encephalomyelitis (EAE). As the influence of NaCl on macrophages is largely unclear, we wanted to evaluate the influence of NaCl on proinflammatory macrophage responses in the context of CNS autoimmunity. Murine and human macrophage responses were investigated in vitro and in vivo under homeostatic conditions, upon stimulation as well as during MOG-induced EAE. Furthermore, the impact of transferred NaCltreated macrophages on EAE disease severity was assessed. Murine NaCl-treated macrophages exhibited a strong pro-inflammatory phenotype upon stimulation characterized by significantly higher production of TNFa and IL-12 and increased expression of immune-stimulatory molecules such as MHC-II and CD40. Mice receiving a NaCl-high diet showed significant aggravation in clinical EAE severity compared to mice receiving a normal diet accompanied by a strongly activated phenotype of CNS macrophages at the peak of EAE. Transfer of NaCl-conditioned macrophages into EAE-diseased animals resulted in a significant aggravation of disease severity when compared to transfer of untreated macrophages, thus underlining the pathophysiological relevance of NaCl for macrophage activation in the context of EAE. Importantly, also in human monocytes, NaCl induced increased production of pro-inflammatory cytokines TNFa and IL-12 as well as enhanced expression of the immunomodulatory surface markers HLA-DR, CD80, CD86 and CD40. NaCl-high diet promotes a pro-inflammatory phenotype in macrophages that aggravates CNS autoimmunity. Further studies are warranted to determine the relevance of increased dietary NaCl uptake in humans for MS disease incidence and disease severity. doi:10.1016/j.jneuroim.2014.08.410
507 The bile acid receptor FXR controls CNS autoimmunity in an IL-10-dependent fashion Stephanie Huckea, Martin Herolda, Marie Liebmanna, Anita Posevitz-Fejfara, Tanja Kuhlmannb, Heinz Wiendla, Luisa Klotza a
Department of Neurology, University hospital Münster, Münster, Germany; bInstitute of Neuropathology, University hospital Münster, Münster, Germany
Results: Blockade of CXCR2 reduced infarct volumes and improved functional outcome in hypercholesterolemic but not in control mice. SB225002 treatment inhibits ischemia-induced increase in peripheral neutrophils, which was associated with a reduced CXCR2 expression and a reduced proportion of viable neutrophils in the bone marrow of ischemic SB225002-treated hypercholesterolemic mice. Neutrophil infiltration into ischemic brains was reduced by CXCR2 blockade in both experimental settings. Conclusion: Whereas SB225002 treatment does not protect the ischemic brain of normocholesterolemic mice, blockade of CXCR2 reduces cerebral tissue injury and improves functional outcome in hypercholesterolemic mice. Interestingly, the neuroprotective effect of SB225002 in hypercholesterolemic mice was associated with an inhibition of ischemia-induced peripheral neutrophilia which might be caused by an increased neutrophil apoptosis in the bone marrow as a result of an increased CXCR2 expression on neutrophils of ischemic hypercholesterolemic mice. Our data demonstrate that pre-clinical and clinical trials should pay more attention to inflammation-associated co-morbidities and particularly emphasize the role of neutrophils in this multifactor associated disease setting.
doi:10.1016/j.jneuroim.2014.08.408
52 Investigating the role of cystatin C in experimental autoimmune encephalomyelitis Vahid Hoghooghia, Shalina S. Ousmanb a
Faculty of Medicine, Department of Neuroscience, University of Calgary, Calgary, Canada; bFaculty of Medicine, Department of Clinical Neurosciences, University of Calgary, Calgary, Canada Multiple sclerosis (MS) is an autoimmune disease characterized by inflammation, demyelination and neurodegeneration of the central nervous system (CNS). The disease is associated with the enhanced and down-regulated expression of scores of genes and proteins but the function of most of these molecules is poorly understood. Cystatin C (CysC) mRNA level is enhanced in the brains of MS subjects and variable amounts of the protein have been found in serum and cerebrospinal fluid of patients. We have also found increased CysC protein expression in the CNS of mice with experimental allergic encephalomyelitis (EAE), an animal model of MS. The function of CysC in MS and EAE however is unclear. CysC is an inhibitor of cysteine proteases including cathepsins B, H, K, L, and S and it is expressed by astrocytes, neurons, microglia and macrophages. Both protective and detrimental effects of CysC have been reported. Due to its decreased expression when macrophages are activated and, its therapeutic effect in collagen-induced arthritis, an anti-inflammatory function for this protease inhibitor has been implied. However, this protease inhibitor has been demonstrated to both prevent cell death and to mediate neurodegeneration. Further, antiCysC promoted the differentiation of oligodendrocyte precursor cells into oligodendrocytes (OLs) suggesting a negative role of this molecule in OL biology. It is therefore unclear what role CysC would play in MS and whether the cell type and environment define its biology. We are investigating the function of CysC in EAE using mice that are null and transgenic for the protein. Our preliminary data shows that CysC has a detrimental role in EAE since it promotes and suppresses clinical disease in CysC overexpressing and knockout mice respectively. Our ongoing studies will dissect whether immunological and/or neurobiological mechanisms underlie the negative effect of CysC in EAE.
153
Supported by a studentship to VH and an operating grant to SSO from the Multiple Sclerosis Society of Canada. doi:10.1016/j.jneuroim.2014.08.409
153 Sodium chloride-high diet promotes pro-inflammatory macrophage activation and aggravates central nervous system autoimmunity Stephanie Hucke, Melanie Eschborn, Annika Engbers, Heinz Wiendl, Luisa Klotz Department of Neurology, University of Muenster, Muenster, Germany It has long been debated whether environmental factors such as nutrition may have an influence on Multiple Sclerosis (MS) incidence and severity. Recently it was shown that a sodium chloride (NaCl)rich diet influences T cell responses during autoimmunity of the central nervous system (CNS) in the animal model of MS, i.e. experimental autoimmune encephalomyelitis (EAE). As the influence of NaCl on macrophages is largely unclear, we wanted to evaluate the influence of NaCl on proinflammatory macrophage responses in the context of CNS autoimmunity. Murine and human macrophage responses were investigated in vitro and in vivo under homeostatic conditions, upon stimulation as well as during MOG-induced EAE. Furthermore, the impact of transferred NaCltreated macrophages on EAE disease severity was assessed. Murine NaCl-treated macrophages exhibited a strong pro-inflammatory phenotype upon stimulation characterized by significantly higher production of TNFa and IL-12 and increased expression of immune-stimulatory molecules such as MHC-II and CD40. Mice receiving a NaCl-high diet showed significant aggravation in clinical EAE severity compared to mice receiving a normal diet accompanied by a strongly activated phenotype of CNS macrophages at the peak of EAE. Transfer of NaCl-conditioned macrophages into EAE-diseased animals resulted in a significant aggravation of disease severity when compared to transfer of untreated macrophages, thus underlining the pathophysiological relevance of NaCl for macrophage activation in the context of EAE. Importantly, also in human monocytes, NaCl induced increased production of pro-inflammatory cytokines TNFa and IL-12 as well as enhanced expression of the immunomodulatory surface markers HLA-DR, CD80, CD86 and CD40. NaCl-high diet promotes a pro-inflammatory phenotype in macrophages that aggravates CNS autoimmunity. Further studies are warranted to determine the relevance of increased dietary NaCl uptake in humans for MS disease incidence and disease severity. doi:10.1016/j.jneuroim.2014.08.410
507 The bile acid receptor FXR controls CNS autoimmunity in an IL-10-dependent fashion Stephanie Huckea, Martin Herolda, Marie Liebmanna, Anita Posevitz-Fejfara, Tanja Kuhlmannb, Heinz Wiendla, Luisa Klotza a
Department of Neurology, University hospital Münster, Münster, Germany; bInstitute of Neuropathology, University hospital Münster, Münster, Germany