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Yang R, Lin TH, Zhan J, Lai S, Song C, Sun P, Ye Z, Wallendorf M, George A, Cross AH, Song SK. Diffusion basis spectrum imaging measures anti-inflammatory and neuroprotective effects of fingolimod on murine optic neuritis. NEUROIMAGE-CLINICAL 2021; 31:102732. [PMID: 34166868 PMCID: PMC8240023 DOI: 10.1016/j.nicl.2021.102732] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 06/12/2021] [Accepted: 06/14/2021] [Indexed: 10/30/2022]
Abstract
OBJECTIVE To prospectively determine whether diffusion basis spectrum imaging (DBSI) detects, differentiates and quantitates coexisting inflammation, demyelination, axonal injury and axon loss in mice with optic neuritis (ON) due to experimental autoimmune encephalomyelitis (EAE), and to determine if DBSI accurately measures effects of fingolimod on underlying pathology. METHODS EAE was induced in 7-week-old C57BL/6 female mice. Visual acuity (VA) was assessed daily to detect onset of ON after which daily oral-treatment with either fingolimod (1 mg/kg) or saline was given for ten weeks. In vivo DBSI scans of optic nerves were performed at baseline, 2-, 6- and 10-weeks post treatment. DBSI-derived metrics including restricted isotropic diffusion tensor fraction (putatively reflecting cellularity), non-restricted isotropic diffusion tensor fraction (putatively reflecting vasogenic edema), DBSI-derived axonal volume, axial diffusivity, λ∥ (putatively reflecting axonal integrity), and increased radial diffusivity, λ⊥ (putatively reflecting demyelination). Mice were killed immediately after the last DBSI scan for immunohistochemical assessment. RESULTS Optic nerves of fingolimod-treated mice exhibited significantly better (p < 0.05) VA than saline-treated group at each time point. During ten-week of treatment, DBSI-derived non-restricted and restricted-isotropic-diffusion-tensor fractions, and axonal volumes were not significantly different (p > 0.05) from the baseline values in fingolimod-treated mice. Transient DBSI-λ∥ decrease and DBSI-λ⊥ increase were detected during Fingolimod treatment. DBSI-derived metrics assessed in vivo significantly correlated (p < 0.05) with the corresponding histological markers. CONCLUSION DBSI was used to assess changes of the underlying optic nerve pathologies in EAE mice with ON, exhibiting great potential as a noninvasive outcome measure for monitoring disease progression and therapeutic efficacy for MS.
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Affiliation(s)
- Ruimeng Yang
- Department of Radiology, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong 510640, China; Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Tsen-Hsuan Lin
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jie Zhan
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Shengsheng Lai
- Department of Medical Equipment, Guangdong Food and Drug Vocational College, Guangzhou, Guangdong 510520, China
| | - Chunyu Song
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Peng Sun
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zezhong Ye
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michael Wallendorf
- Department of Biostatistics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Ajit George
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Anne H Cross
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Sheng-Kwei Song
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA.
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Nematullah M, Hoda MN, Nimker S, Khan F. Restoration of PP2A levels in inflamed microglial cells: Important for neuroprotective M2 microglial viability. Toxicol Appl Pharmacol 2020; 409:115294. [PMID: 33069748 DOI: 10.1016/j.taap.2020.115294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/01/2020] [Accepted: 10/13/2020] [Indexed: 11/16/2022]
Abstract
PP2A, a trimeric Serine/Threonine Protein Phosphatase 2A highly expressed in brain, is a master regulator of cellular functions. Reduction in PP2A activity has been linked to progression of microglial mediated neuroinflammatory diseases. Inflammatory conditions are characterized by increased population of CD86+ve M1 cells and a therapeutic strategy to polarize microglial cells towards CD206+ve M2 cells is the need of hour. In this paper we analyzed A: whether the level of PP2A is altered in CD86+ve cells, B: whether FTY720, a known modulator of PP2A, is able to restore the level of PP2A in inflamed CD86+ve cells. Results revealed that PP2A activity was significantly diminished in inflamed cells but the surprising observation was the cell viability of only 35.99% upon FTY720 treatment in inflamed cells lacking basal PP2A activity. A sharp increase at mRNA level of CD95 and ASK-1 indicated that apoptosis occurred in these cells through CD95/ASK-1/JNK pathway. Importantly, flow cytometric analysis revealed apoptosis of not only CD86+ve cells but also CD206+ve cells. Previous studies have reported that FTY720 polarizes microglial cells towards M2 states; however apoptosis of M2 cells was not studied. As western blot analysis revealed that FTY720 failed to completely restore PP2A, another PP2A modulator, Memantine, was used for co-treatment. Upon co-treatment, the level of PP2A was completely restored and also viability of microglial cells was significantly improved with a significant reduction in apoptosis of M2 cells. These findings suggest that co-treatment strategy may prove beneficial to balance M1/M2 microglial population, thereby improving neuronal functions.
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Affiliation(s)
- Md Nematullah
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - M N Hoda
- Department of Neurology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Centre, Dignity Health, Phoenix, AZ 85013, USA
| | | | - Farah Khan
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India.
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Molecular Effects of FDA-Approved Multiple Sclerosis Drugs on Glial Cells and Neurons of the Central Nervous System. Int J Mol Sci 2020; 21:ijms21124229. [PMID: 32545828 PMCID: PMC7352301 DOI: 10.3390/ijms21124229] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/08/2020] [Accepted: 06/10/2020] [Indexed: 02/07/2023] Open
Abstract
Multiple sclerosis (MS) is characterized by peripheral and central inflammatory features, as well as demyelination and neurodegeneration. The available Food and Drug Administration (FDA)-approved drugs for MS have been designed to suppress the peripheral immune system. In addition, however, the effects of these drugs may be partially attributed to their influence on glial cells and neurons of the central nervous system (CNS). We here describe the molecular effects of the traditional and more recent FDA-approved MS drugs Fingolimod, Dimethyl Fumarate, Glatiramer Acetate, Interferon-β, Teriflunomide, Laquinimod, Natalizumab, Alemtuzumab and Ocrelizumab on microglia, astrocytes, neurons and oligodendrocytes. Furthermore, we point to a possible common molecular effect of these drugs, namely a key role for NFκB signaling, causing a switch from pro-inflammatory microglia and astrocytes to anti-inflammatory phenotypes of these CNS cell types that recently emerged as central players in MS pathogenesis. This notion argues for the need to further explore the molecular mechanisms underlying MS drug action.
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Yazdi A, Ghasemi‐Kasman M, Javan M. Possible regenerative effects of fingolimod (FTY720) in multiple sclerosis disease: An overview on remyelination process. J Neurosci Res 2019; 98:524-536. [DOI: 10.1002/jnr.24509] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 07/19/2019] [Accepted: 07/22/2019] [Indexed: 12/11/2022]
Affiliation(s)
- Azadeh Yazdi
- Department of Physiology, School of Medicine Isfahan University of Medical Sciences Isfahan Iran
| | - Maryam Ghasemi‐Kasman
- Cellular and Molecular Biology Research Center Health Research Institute, Babol University of Medical Sciences Babol Iran
- Neuroscience Research Center Health Research Institute, Babol University of Medical Sciences Babol Iran
| | - Mohammad Javan
- Department of Physiology, Faculty of Medical Sciences Tarbiat Modares University Tehran Iran
- Department of Brain and Cognitive Sciences, Cell Science Research Center Royan Institute for Stem Cell Biology and Technology, ACECR Tehran Iran
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Herold S, Kumar P, Jung K, Graf I, Menkhoff H, Schulz X, Bähr M, Hein K. CatWalk gait analysis in a rat model of multiple sclerosis. BMC Neurosci 2016; 17:78. [PMID: 27903258 PMCID: PMC5131412 DOI: 10.1186/s12868-016-0317-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 11/28/2016] [Indexed: 11/10/2022] Open
Abstract
Background
Myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE) is a widely used animal model for multiple sclerosis. The characteristic feature of the MOG-EAE model in Brown Norway rats is consistent involvement of the spinal cord resulting in limb paresis. The aim of the study was to investigate whether early subclinical gait abnormalities are present in this animal model and can be detected by CatWalk XT, a fully automated gait analysis system. Furthermore, we investigated the usability of CatWalk system for treatment studies. Results Our gait analysis showed no preclinical abnormalities in MOG-EAE animals. Nevertheless, we characterized a combination of gait parameters that display a high predictive capacity in regard to disease onset. Our detailed histopathological analysis of the spinal cord revealed that lesion formation starts in the lumbar region and propagates toward the cervical part of the spinal cord during the disease course. In the treatment study, the stabilization of gait parameters under the treatment with methylprednisolone was detected in CatWalk as well as in traditional EAE-scoring system. Conclusions The results from CatWalk test indicate no benefit of lab-intensive automated gait system in EAE-model with chronic-progressive disease course as well as in therapeutic studies with pronounced effect on the severity of clinical symptoms. However, due to its quantitative and objective nature this system may display a refined test to detect small but functional relevant changes in regeneration-orientated studies.
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Affiliation(s)
- Sabine Herold
- Department of Neurology, University Medicine Göttingen, Robert-Koch Straße 40, 37073, Göttingen, Germany
| | - Prateek Kumar
- Department of Neurology, University Medicine Göttingen, Robert-Koch Straße 40, 37073, Göttingen, Germany
| | - Klaus Jung
- Department of Medical Biometry and Statistical Bioinformatics, University Medicine Göttingen, Robert-Koch Straße 40, 37073, Göttingen, Germany.,Institute of Animal Breeding and Genetics, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Irina Graf
- Department of Neurology, University Medicine Göttingen, Robert-Koch Straße 40, 37073, Göttingen, Germany
| | - Henrike Menkhoff
- Department of Neurology, University Medicine Göttingen, Robert-Koch Straße 40, 37073, Göttingen, Germany
| | - Xenia Schulz
- Department of Medical Biometry and Statistical Bioinformatics, University Medicine Göttingen, Robert-Koch Straße 40, 37073, Göttingen, Germany
| | - Mathias Bähr
- Department of Neurology, University Medicine Göttingen, Robert-Koch Straße 40, 37073, Göttingen, Germany
| | - Katharina Hein
- Department of Neurology, University Medicine Göttingen, Robert-Koch Straße 40, 37073, Göttingen, Germany. .,Department of Neurology, University Hospital, Robert-Koch-Strasse 40, 37075, Göttingen, Germany.
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Abstract
OBJECTIVE In this work, we evaluated the association of human immunodeficiency virus (HIV) infection and methamphetamine (METH) use with mitochondrial injury in the brain and its implication on neurocognitive impairment. DESIGN Mitochondria carry their genome (mtDNA) and play a critical role in cellular processes in the central nervous system. METH is commonly used in HIV-infected populations. HIV infection and METH use can cause damage to mtDNA and lead to neurocognitive morbidity. We evaluated HIV infection and METH use with mitochondrial injury in the brain. METHODS We obtained white and gray matter from Brodmann areas 7, 8, 9, 46 of the following: HIV-infected individuals with history of past METH use (HIV+METH+, n = 16), HIV-infected individuals with no history of past METH use (HIV+METH-, n = 11), and HIV-negative controls (HIV-METH-, n = 30). We used the 'common deletion', a 4977 bp mutation, as a measurement of mitochondrial injury, and quantified levels of mtDNA and 'common deletion' by droplet digital PCR, and evaluated in relation to neurocognitive functioning [Global Deficit Score (GDS)]. RESULTS Levels of mtDNA and mitochondrial injury were highest in white matter of Brodmann area 46. A higher relative proportion of mtDNA carrying the 'common deletion' was associated with lower GDS (P < 0.01) in HIV+METH+ but higher GDS (P < 0.01) in HIV+METH-. CONCLUSIONS Increased mitochondrial injury was associated with worse neurocognitive function in HIV+METH- individuals. Among HIV+METH+ individuals, an opposite effect was seen.
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Yazdi A, Baharvand H, Javan M. Enhanced remyelination following lysolecithin-induced demyelination in mice under treatment with fingolimod (FTY720). Neuroscience 2015; 311:34-44. [PMID: 26475743 DOI: 10.1016/j.neuroscience.2015.10.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 10/07/2015] [Accepted: 10/08/2015] [Indexed: 01/24/2023]
Abstract
Multiple sclerosis (MS) is a chronic, progressive demyelinating disorder which affects the central nervous system (CNS) and is recognized as the major cause of nervous system disability in young adults. Enhancing myelin repair by stimulating endogenous progenitors is a main goal in efforts for MS treatment. Fingolimod (FTY720) which is administrated as an oral medicine for relapsing-remitting MS has direct effects on neural cells. In this study, we hypothesized if daily treatment with FTY720 enhances endogenous myelin repair in a model of local demyelination induced by lysolecithin (LPC). We examined the response of inflammatory cells as well as resident OPCs and evaluated the number of newly produced myelinating cells in animals which were under daily treatment with FTY720. FTY720 at doses 0.3 and 1mg/kg decreased the inflammation score at the site of LPC injection and decreased the extent of demyelination. FTY720 especially at the lower dose increased the number of remyelinated axons and newly produced myelinating cells. These data indicate that repetitive treatment with FTY720, behind an anti-inflammatory effect, exerts beneficial effects on the process of endogenous repair of demyelinating insults.
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Affiliation(s)
- A Yazdi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - H Baharvand
- Department of Stem Cells and Developmental Biology at Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran; Department of Developmental Biology, University of Science and Culture, ACECR, Tehran, Iran
| | - M Javan
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Department of Stem Cells and Developmental Biology at Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran.
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Herold S, Kumar P, Wichert SP, Kretzschmar B, Bähr M, Rossner MJ, Hein K. Neurodegeneration in Autoimmune Optic Neuritis Is Associated with Altered APP Cleavage in Neurons and Up-Regulation of p53. PLoS One 2015; 10:e0138852. [PMID: 26426258 PMCID: PMC4591258 DOI: 10.1371/journal.pone.0138852] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 09/06/2015] [Indexed: 11/19/2022] Open
Abstract
Multiple Sclerosis (MS) is a chronic autoimmune inflammatory disease of the central nervous system (CNS). Histopathological and radiological analysis revealed that neurodegeneration occurs early in the disease course. However, the pathological mechanisms involved in neurodegeneration are poorly understood. Myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE) in Brown Norway rats (BN-rats) is a well-established animal model, especially of the neurodegenerative aspects of MS. Previous studies in this animal model indicated that loss of retinal ganglion cells (RGCs), the neurons that form the axons of the optic nerve, occurs in the preclinical phase of the disease and is in part independent of overt histopathological changes of the optic nerve. Therefore, the aim of this study was to identify genes which are involved in neuronal cell loss at different disease stages of EAE. Furthermore, genes that are highly specific for autoimmune-driven neurodegeneration were compared to those regulated in RGCs after optic nerve axotomy at corresponding time points. Using laser capture micro dissection we isolated RNA from unfixed RGCs and performed global transcriptome analysis of retinal neurons. In total, we detected 582 genes sequentially expressed in the preclinical phase and 1150 genes in the clinical manifest EAE (P < 0.05, fold-induction >1.5). Furthermore, using ingenuity pathway analysis (IPA), we identified amyloid precursor protein (APP) as a potential upstream regulator of changes in gene expression in the preclinical EAE but neither in clinical EAE, nor at any time point after optic nerve transection. Therefore, the gene pathway analysis lead to the hypothesis that altered cleavage of APP in neurons in the preclinical phase of EAE leads to the enhanced production of APP intracellular domain (AICD), which in turn acts as a transcriptional regulator and thereby initiates an apoptotic signaling cascade via up-regulation of the target gene p53.
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Affiliation(s)
- Sabine Herold
- Department of Neurology, University Medicine Göttingen, Göttingen, Germany
| | - Prateek Kumar
- Department of Neurology, University Medicine Göttingen, Göttingen, Germany
| | - Sven P. Wichert
- Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilians University Munich, Munich, Germany
| | | | - Mathias Bähr
- Department of Neurology, University Medicine Göttingen, Göttingen, Germany
| | - Moritz J. Rossner
- Molecular and Behavioral Neurobiology, Department of Psychiatry, Ludwig Maximilians University Munich, Munich, Germany
| | - Katharina Hein
- Department of Neurology, University Medicine Göttingen, Göttingen, Germany
- * E-mail:
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Kumar P, Friebe K, Schallhorn R, Moinfar Z, Nau R, Bähr M, Schütze S, Hein K. Systemic Escherichia coli infection does not influence clinical symptoms and neurodegeneration in experimental autoimmune encephalomyelitis. BMC Neurosci 2015; 16:36. [PMID: 26088203 PMCID: PMC4472157 DOI: 10.1186/s12868-015-0172-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 06/03/2015] [Indexed: 01/13/2023] Open
Abstract
Background Systemic infections can influence the course of multiple sclerosis (MS), especially by driving recurrent acute episodes. The question whether the infection enhances tissue damage is of great clinical importance and cannot easily be assessed in clinical trials. Here, we investigated the effects of a systemic infection with Escherichia coli, a Gram-negative bacterium frequently causing urinary tract infections, on the clinical course as well as on neurodegeneration in experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Methods Rats were immunized with myelin oligodendrocyte glycoprotein (MOG1–125) and challenged intraperitoneally with live E. coli K1 in the preclinical or in the clinical phase of the disease. To ensure the survival of animals, antibiotic treatment with ceftriaxone was initiated 36 h after the infection and continued for 3 consecutive days. Results Systemic infection with E. coli did not influence the onset of clinical EAE symptoms or disease severity. Analysis of the optic nerve and retinal ganglion cells revealed no significant changes in the extent of inflammatory infiltrates, demyelination and neurodegeneration after E. coli infection. Conclusions We could not confirm the detrimental effect of lipopolysaccharide-induced systemic inflammation, a model frequently used to mimic the bacterial infection, previously observed in animal models of MS. Our results indicate that the effect of an acute E. coli infection on the course of MS is less pronounced than suspected and underline the need for adequate models to test the role of systemic infections in the pathogenesis of MS.
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Affiliation(s)
- Prateek Kumar
- Department of Neurology, University Hospital, University Medical Center Göttingen, Robert-Koch-Strasse 40, 37075, Göttingen, Germany.
| | - Katharina Friebe
- Department of Neurology, University Hospital, University Medical Center Göttingen, Robert-Koch-Strasse 40, 37075, Göttingen, Germany.
| | - Rieka Schallhorn
- Department of Neurology, University Hospital, University Medical Center Göttingen, Robert-Koch-Strasse 40, 37075, Göttingen, Germany.
| | - Zahra Moinfar
- Department of Neurology, University Hospital, University Medical Center Göttingen, Robert-Koch-Strasse 40, 37075, Göttingen, Germany.
| | - Roland Nau
- Institute of Neuropathology, University Medical Center Göttingen, 37075, Göttingen, Germany.
| | - Mathias Bähr
- Department of Neurology, University Hospital, University Medical Center Göttingen, Robert-Koch-Strasse 40, 37075, Göttingen, Germany.
| | - Sandra Schütze
- Institute of Neuropathology, University Medical Center Göttingen, 37075, Göttingen, Germany.
| | - Katharina Hein
- Department of Neurology, University Hospital, University Medical Center Göttingen, Robert-Koch-Strasse 40, 37075, Göttingen, Germany.
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Brimonidine suppresses loss of retinal neurons and visual function in a murine model of optic neuritis. Neurosci Lett 2015; 592:27-31. [DOI: 10.1016/j.neulet.2015.02.059] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 01/31/2015] [Accepted: 02/27/2015] [Indexed: 02/05/2023]
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Kumar P, Kretzschmar B, Herold S, Nau R, Kreutzfeldt M, Schütze S, Bähr M, Hein K. Beneficial effect of chronic Staphylococcus aureus infection in a model of multiple sclerosis is mediated through the secretion of extracellular adherence protein. J Neuroinflammation 2015; 12:22. [PMID: 25644616 PMCID: PMC4322648 DOI: 10.1186/s12974-015-0241-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 01/10/2015] [Indexed: 12/15/2022] Open
Abstract
Background Bacterial infections have been assumed to worsen multiple sclerosis (MS) disease symptoms and to lead to increased neurodegeneration. However, the underlying biological mechanisms for these effects are complex and poorly understood. Here, we assessed the disease-modulating effects of chronic infection with Staphylococcus aureus, a common human pathogen, on the clinical course and the extent of neurodegeneration in experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Methods To conduct this study, we established a persistent chronic infection in female brown Norway rats by inoculating Staphylococcus aureus (S. aureus) bacteria in a subcutaneously implanted tissue cages. Results In this study, we observed that the introduction of a localized S. aureus infection during the subclinical phase of EAE induced a chronic systemic inflammatory response, consisting of increased T- and B-cell counts and systemic production of proinflammatory cytokines. Unexpectedly, the S. aureus infection completely prevented the development of clinical EAE, and markedly reduced inflammatory infiltration and demyelination of the optic nerve, while it increased the number of surviving retinal neurons. Using a S. aureus strain that lacked the extracellular adherence protein (Eap), we determined that the extracellular adherence protein is at least partially responsible for the inhibitory effect of S. aureus infection on autoimmune inflammation of the central nervous system. Conclusions Our results demonstrate for the first time that chronic infection with S. aureus has a beneficial effect on EAE, indicating a dual role of infection in the pathogenesis of MS. We also showed that secretion of Eap by S. aureus plays a major role in preventing autoimmune inflammation of the CNS. Moreover, we identified Eap as a factor responsible for this protective effect.
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Affiliation(s)
- Prateek Kumar
- Department of Neurology, University Medicine Goettingen, Robert-Koch-Strasse 40, 37075, Goettingen, Germany.
| | - Benedikt Kretzschmar
- Department of Neurology, University Medicine Goettingen, Robert-Koch-Strasse 40, 37075, Goettingen, Germany.
| | - Sabine Herold
- Department of Neurology, University Medicine Goettingen, Robert-Koch-Strasse 40, 37075, Goettingen, Germany.
| | - Roland Nau
- Institute of Neuropathology, University Medicine Goettingen, Goettingen, 37075, Germany.
| | - Mario Kreutzfeldt
- Department of Pathology and Immunology, Centre Médical Universitaire 1, Rue Michel-Servet 1211, Geneva 4, Switzerland.
| | - Sandra Schütze
- Institute of Neuropathology, University Medicine Goettingen, Goettingen, 37075, Germany.
| | - Mathias Bähr
- Department of Neurology, University Medicine Goettingen, Robert-Koch-Strasse 40, 37075, Goettingen, Germany.
| | - Katharina Hein
- Department of Neurology, University Medicine Goettingen, Robert-Koch-Strasse 40, 37075, Goettingen, Germany.
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Das A, Barker DA, Wang T, Lau CM, Lin Y, Botchwey EA. Delivery of bioactive lipids from composite microgel-microsphere injectable scaffolds enhances stem cell recruitment and skeletal repair. PLoS One 2014; 9:e101276. [PMID: 25077607 PMCID: PMC4117484 DOI: 10.1371/journal.pone.0101276] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 06/04/2014] [Indexed: 01/07/2023] Open
Abstract
In this study, a microgel composed of chitosan and inorganic phosphates was used to deliver poly(lactic-co-glycolic acid) (PLAGA) microspheres loaded with sphingolipid growth factor FTY720 to critical size cranial defects in Sprague Dawley rats. We show that sustained release of FTY720 from injected microspheres used alone or in combination with recombinant human bone morphogenic protein-2 (rhBMP2) improves defect vascularization and bone formation in the presence and absence of rhBMP2 as evaluated by quantitative microCT and histological measurements. Moreover, sustained delivery of FTY720 from PLAGA and local targeting of sphingosine 1-phosphate (S1P) receptors reduces CD45+ inflammatory cell infiltration, promotes endogenous recruitment of CD29+CD90+ bone progenitor cells and enhances the efficacy of rhBMP2 from chitosan microgels. Companion in vitro studies suggest that selective activation of sphingosine receptor subtype-3 (S1P3) via FTY720 treatment induces smad-1 phosphorylation in bone-marrow stromal cells. Additionally, FTY720 enhances stromal cell-derived factor-1 (SDF-1) mediated chemotaxis of CD90+CD11B-CD45- bone progenitor cells in vitro after stimulation with rhBMP2. We believe that use of such small molecule delivery formulations to recruit endogenous bone progenitors may be an attractive alternative to exogenous cell-based therapy.
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Affiliation(s)
- Anusuya Das
- Department of Orthopaedic Surgery, University of Virginia, Charlottesville, Virginia, United States of America
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States of America
| | - Daniel A. Barker
- Department of Otolaryngology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Tiffany Wang
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Cheryl M. Lau
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Yong Lin
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States of America
| | - Edward A. Botchwey
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
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Kretzschmar B, Hein K, Moinfar Z, Könnecke B, Sättler MB, Hess H, Weissert R, Bähr M. Treatment with atacicept enhances neuronal cell death in a rat model of optic neuritis. J Neuroimmunol 2014; 268:58-63. [DOI: 10.1016/j.jneuroim.2014.01.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 01/07/2014] [Accepted: 01/09/2014] [Indexed: 01/01/2023]
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Chan AY, Mann SN, Chen H, Stone DU, Carr DJJ, Mandal NA. Sphingolipids in ocular inflammation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 801:623-9. [PMID: 24664751 DOI: 10.1007/978-1-4614-3209-8_78] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Sphingolipids are essential to cell membrane structure and the development and maintenance of neural tissues. The role of bioactive sphingolipids has been established in numerous cellular events, including cell survival, growth, and apoptosis. Ocular inflammatory and autoimmune diseases involve activation and migration of endothelial cells, neovascularization, and infiltration of immune cells into various tissues. Clinically, the impact and role of sphingolipid-mediated signaling is increasingly being appreciated in the pathogenesis and treatment of diseases ranging from multiple sclerosis to neovascularization in age-related macular degeneration and diabetic retinopathy. In this review, we discuss our current knowledge and understanding of sphingolipid metabolism and signaling associated with the pathogenesis of ocular diseases.
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Affiliation(s)
- Annie Y Chan
- Department of Ophthalmology, OUHSC, Oklahoma City, OK, USA,
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15
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Abstract
The development of fingolimod, an unselective functional antagonist of the interactions between sphingosine 1 phosphate (S1P) and sphingosine 1 phosphate receptors (S1PRs), as the first oral therapy for multiple sclerosis (MS) has been a milestone. The parallel intensive research on the role of S1P, sphingosine kinases, and the five known S1PRs, their tissue distribution and expression in physiological and pathological conditions have led to a wide range of interesting findings. The initial focus of this research in the context of developing fingolimod as a treatment of MS has been on its immunological effects. The wide distribution and important roles of sphingosine, its metabolites, and their receptors in the central nervous system (CNS) in general, in myelin, and in all cell types of this organ have spurred interest to examine S1P and its five receptors in the brain as well. The present review will concentrate on the latter area and give a brief overview of what is known about S1P/S1PR interactions in the CNS in physiological and pathological conditions.
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Wang X, Brieland JK, Kim JH, Chen YJ, O’Neal J, O’Neil SR, Tu TW, Trinkaus K, Song SK. Diffusion tensor imaging detects treatment effects of FTY720 in experimental autoimmune encephalomyelitis mice. NMR IN BIOMEDICINE 2013; 26:1742-1750. [PMID: 23939596 PMCID: PMC3838438 DOI: 10.1002/nbm.3012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 07/14/2013] [Accepted: 07/16/2013] [Indexed: 05/29/2023]
Abstract
Fingolimod (FTY720) is an orally available sphingosine-1-phosphate (S1P) receptor modulator reducing relapse frequency in patients with relapsing-remitting multiple sclerosis (RRMS). In addition to immunosuppression, neuronal protection by FTY720 has also been suggested, but remains controversial. Axial and radial diffusivities derived from in vivo diffusion tensor imaging (DTI) were employed as noninvasive biomarkers of axonal injury and demyelination to assess axonal protection by FTY720 in experimental autoimmune encephalomyelitis (EAE) mice. EAE was induced through active immunization of C57BL/6 mice using myelin oligodendrocyte glycoprotein peptide 35-55 (MOG(35-55)). We evaluated both the prophylactic and therapeutic treatment effect of FTY720 at doses of 3 and 10 mg/kg on EAE mice by daily clinical scoring and end-point in vivo DTI. Prophylactic administration of FTY720 suppressed the disease onset and prevented axon and myelin damage when compared with EAE mice without treatment. Therapeutic treatment by FTY720 did not prevent EAE onset, but reduced disease severity, improving axial and radial diffusivity towards the control values without statistical significance. Consistent with previous findings, in vivo DTI-derived axial and radial diffusivity correlated with clinical scores in EAE mice. The results support the use of in vivo DTI as an effective outcome measure for preclinical drug development.
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Affiliation(s)
- Xiaojie Wang
- Department of Chemistry, Washington University, St. Louis, MO, USA
| | | | - Joong H. Kim
- Department of Radiology, Washington University, St. Louis, MO, USA
| | - Ying-Jr Chen
- Department of Chemistry, Washington University, St. Louis, MO, USA
| | | | | | - Tsang-Wei Tu
- Department of Mechanical Engineering and Materials Science, St. Louis, MO, USA
| | - Kathryn Trinkaus
- Department of Biostatistics, Washington University, St. Louis, MO, USA
| | - Sheng-Kwei Song
- Department of Radiology, Washington University, St. Louis, MO, USA
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NADH-dehydrogenase type-2 suppresses irreversible visual loss and neurodegeneration in the EAE animal model of MS. Mol Ther 2013; 21:1876-88. [PMID: 23752309 DOI: 10.1038/mt.2013.104] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 04/21/2013] [Indexed: 11/08/2022] Open
Abstract
To address mitochondrial dysfunction that mediates irreversible visual loss and neurodegeneration of the optic nerve in the experimental autoimmune encephalomyelitis (EAE) animal model of multiple sclerosis (MS), mice sensitized for EAE were vitreally injected with self-complementary adenoassociated virus (scAAV) containing the NADH-dehydrogenase type-2 (NDI1) complex I gene that quickly expressed in mitochondria of almost all retinal ganglion cells (RGCs). Visual function assessed by pattern electroretinograms (PERGs) reduced by half in EAE showed no significant reductions with NDI1. Serial optical coherence tomography (OCT) revealed significant inner retinal thinning with EAE that was suppressed by NDI1. Although complex I activity reduced 80% in EAE was not improved by NDI1, in vivo fluorescent probes indicated mitochondrial oxidative stress and apoptosis of the EAE retina were reduced by NDI1. Finally, the 42% loss of axons in the EAE optic nerve was ameliorated by NDI1. Targeting the dysfunctional complex I of EAE responsible for loss of respiration, mitochondrial oxidative stress and apoptosis may be a novel approach to address neuronal and axonal loss responsible for permanent disability that is unaltered by current disease modifying drugs for MS that target inflammation.
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18
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Suppression of Experimental Autoimmune Optic Neuritis by the Novel Agent Fingolimod. J Neuroophthalmol 2013; 33:143-8. [DOI: 10.1097/wno.0b013e31828ea2fc] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Fingolimod: direct CNS effects of sphingosine 1-phosphate (S1P) receptor modulation and implications in multiple sclerosis therapy. J Neurol Sci 2013; 328:9-18. [PMID: 23518370 DOI: 10.1016/j.jns.2013.02.011] [Citation(s) in RCA: 226] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 02/14/2013] [Accepted: 02/15/2013] [Indexed: 11/23/2022]
Abstract
Fingolimod is the first oral disease-modifying therapy approved for relapsing forms of multiple sclerosis (MS). Following phosphorylation in vivo, the active agent, fingolimod phosphate (fingolimod-P), acts as a sphingosine 1-phosphate (S1P) receptor modulator, binding with high affinity to four of the five known S1P receptors (S1P1, S1P3, S1P4 and S1P5). The mechanism of action of fingolimod in MS has primarily been considered as immunomodulatory, whereby fingolimod-P modulates S1P1 on lymphocytes, selectively retaining autoreactive lymphocytes in lymph nodes to reduce damaging infiltration into the central nervous system (CNS). However, emerging evidence indicates that fingolimod has direct effects in the CNS in MS. For example, in the MS animal model of experimental autoimmune encephalomyelitis (EAE), fingolimod is highly efficacious in both a prophylactic and therapeutic setting, yet becomes ineffective in animals selectively deficient for S1P1 on astrocytes, despite maintained normal immunologic receptor expression and functions, and S1P-mediated immune activities. Here we review S1P signaling effects relevant to MS in neural cell types expressing S1P receptors, including astrocytes, oligodendrocytes, neurons, microglia and dendritic cells. The direct effects of fingolimod on these CNS cells observed in preclinical studies are discussed in view of the functional consequences of reducing neurodegenerative processes and promoting myelin preservation and repair. The therapeutic implications of S1P modulation in the CNS are considered in terms of the clinical outcomes of MS, such as reducing MS-related brain atrophy, and other CNS disorders. Additionally, we briefly outline other existing and investigational MS therapies that may also have effects in the CNS.
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20
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Abstract
Optic neuritis can be defined as typical (associated with multiple sclerosis, improving independent of steroid treatment), or atypical (not associated with multiple sclerosis, steroid-dependent improvement). Causes of atypical optic neuritis include connective tissue diseases (eg, lupus), vasculitis, sarcoidosis, or neuromyelitis optica. In this manuscript, updated treatment options for both typical and atypical optic neuritis are reviewed. Conventional treatments, such as corticosteroids, therapeutic plasma exchange, and intravenous immunoglobulin therapy are all discussed with commentary regarding evidence-based outcomes. Less commonly used treatments and novel purported therapies for optic neuritis are also reviewed. Special scenarios in the treatment of optic neuritis – pediatric optic neuritis, acute demyelinating encephalomyelitis, and optic neuritis occurring during pregnancy – are specifically examined.
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Affiliation(s)
- John H Pula
- Division of Neuro-ophthalmology, University of Illinois College of Medicine at Peoria, Peoria
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21
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Choi JW, Chun J. Lysophospholipids and their receptors in the central nervous system. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1831:20-32. [PMID: 22884303 DOI: 10.1016/j.bbalip.2012.07.015] [Citation(s) in RCA: 194] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 07/17/2012] [Accepted: 07/18/2012] [Indexed: 02/05/2023]
Abstract
Lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P), two of the best-studied lysophospholipids, are known to influence diverse biological events, including organismal development as well as function and pathogenesis within multiple organ systems. These functional roles are due to a family of at least 11 G protein-coupled receptors (GPCRs), named LPA(1-6) and S1P(1-5), which are widely distributed throughout the body and that activate multiple effector pathways initiated by a range of heterotrimeric G proteins including G(i/o), G(12/13), G(q) and G(s), with actual activation dependent on receptor subtypes. In the central nervous system (CNS), a major locus for these signaling pathways, LPA and S1P have been shown to influence myriad responses in neurons and glial cell types through their cognate receptors. These receptor-mediated activities can contribute to disease pathogenesis and have therapeutic relevance to human CNS disorders as demonstrated for multiple sclerosis (MS) and possibly others that include congenital hydrocephalus, ischemic stroke, neurotrauma, neuropsychiatric disorders, developmental disorders, seizures, hearing loss, and Sandhoff disease, based upon the experimental literature. In particular, FTY720 (fingolimod, Gilenya, Novartis Pharma, AG) that becomes an analog of S1P upon phosphorylation, was approved by the FDA in 2010 as a first oral treatment for MS, validating this class of receptors as medicinal targets. This review will provide an overview and update on the biological functions of LPA and S1P signaling in the CNS, with a focus on results from studies using genetic null mutants for LPA and S1P receptors. This article is part of a Special Issue entitled Advances in Lysophospholipid Research.
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Affiliation(s)
- Ji Woong Choi
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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22
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Ingwersen J, Aktas O, Kuery P, Kieseier B, Boyko A, Hartung HP. Fingolimod in multiple sclerosis: mechanisms of action and clinical efficacy. Clin Immunol 2011; 142:15-24. [PMID: 21669553 DOI: 10.1016/j.clim.2011.05.005] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 05/16/2011] [Accepted: 05/17/2011] [Indexed: 12/22/2022]
Abstract
Fingolimod, also known as FTY720, has recently been approved by the regulatory authorities in the US, EU, Australia, Russia, among others, for the treatment of relapsing-remitting multiple sclerosis. Fingolimod therefore represents the first oral drug for the treatment of this autoimmune disease of the central nervous system. Fingolimod modulates sphingosine-1 phosphate receptors and has unique immunoregulatory properties. Mechanistic studies from animal models have shown that fingolimod prevents immune cells from exiting from the lymphoid tissue and reaching the inflammatory tissue. Indeed, two phase III studies that laid the basis for fingolimod's approval demonstrated that fingolimod efficiently improves the relapse rate compared to both placebo and one of the standard MS medications. In this review, we will summarize the immunological profile of fingolimod, discuss the possible direct neurobiological effects that have been suggested recently and present the clinical data regarding the efficacy and safety profiles of this promising new drug.
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Affiliation(s)
- Jens Ingwersen
- Multiple Sclerosis Center, Department of Neurology, Heinrich-Heine-University of Düsseldorf, Düsseldorf, Germany
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