1
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Wu H, Li N, Peng S, Fu H, Hu Z, Su L. Maresin1 improves hippocampal neuroinflammation and cognitive function in septic rats by activating the SLC7A11 / GPX4 ferroptosis signaling pathway. Int Immunopharmacol 2024; 131:111792. [PMID: 38484667 DOI: 10.1016/j.intimp.2024.111792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 02/19/2024] [Accepted: 02/29/2024] [Indexed: 04/10/2024]
Abstract
Sepsis-associated encephalopathy (SAE) is a prevalent complication of sepsis, with hippocampal neuroinflammation playing a crucial role in SAE-induced cognitive impairment. Maresin1 (MaR1), a bioactive docosahexaenoic acid (DHA) metabolite, demonstrates comprehensive anti-inflammatory and neuroprotective attributes. Yet, its protective efficacy against SAE-induced cognitive decline remains unexplored. In this investigation, we implemented a rat SAE model via cecal ligation and puncture (CLP), while lipopolysaccharide (LPS) stimulation of HT22 cells simulated an in vitro SAE model; both models were pre-treated with MaR1. We evaluated rat learning and memory using a water maze, assessed hippocampal neuron damage via Nissl and FJC staining, and observed mitochondrial alterations through TEM. In vivo and in vitro assays gauged levels of Fe2+, MDA, GSH, and SOD. Additionally, Iba1 expression in the hippocampus was examined via immunofluorescence, while SLC7A11 and GPX4 protein expression levels were determined using western blot. Our findings indicated CLP-induced learning and memory impairment in rats, along with heightened ROS, Fe2+, and MDA levels in hippocampal neurons, diminished GSH and SOD levels, and down-regulated ferroptosis-related proteins (GPX4 and SLC7A11). Remarkably, MaR1 treatment attenuated these adverse effects. In LPS-stimulated HT22 cells, MaR1 lowered lipid ROS and bolstered mitochondrial membrane potential. Nonetheless, the ferroptosis inducer Erastin reversed MaR1's protective effects. Transwell experiments further showed MaR1's potential to inhibit microglia activation triggered by ferroptosis in HT22 cells. Consequently, MaR1 may mitigate hippocampal neuroinflammation via activating the SLC7A11/GPX4 ferroptosis signaling pathway, thus ameliorating SAE-related cognitive impairment.
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Affiliation(s)
- Huiping Wu
- Intensive Care Unit, The First Affiliated Hospital of JinZhou Medical University, Jinzhou 121001, China
| | - Na Li
- Intensive Care Unit, The First Affiliated Hospital of JinZhou Medical University, Jinzhou 121001, China
| | - Shuang Peng
- Intensive Care Unit, The First Affiliated Hospital of JinZhou Medical University, Jinzhou 121001, China
| | - Haiyan Fu
- Intensive Care Unit, The First Affiliated Hospital of JinZhou Medical University, Jinzhou 121001, China
| | - Zhansheng Hu
- Intensive Care Unit, The First Affiliated Hospital of JinZhou Medical University, Jinzhou 121001, China
| | - Longxiang Su
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, 1st Shuaifuyuan, Dongcheng District, Beijing 100730, China.
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2
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Rim C, You MJ, Nahm M, Kwon MS. Emerging role of senescent microglia in brain aging-related neurodegenerative diseases. Transl Neurodegener 2024; 13:10. [PMID: 38378788 PMCID: PMC10877780 DOI: 10.1186/s40035-024-00402-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/31/2024] [Indexed: 02/22/2024] Open
Abstract
Brain aging is a recognized risk factor for neurodegenerative diseases like Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease), but the intricate interplay between brain aging and the pathogenesis of these conditions remains inadequately understood. Cellular senescence is considered to contribute to cellular dysfunction and inflammaging. According to the threshold theory of senescent cell accumulation, the vulnerability to neurodegenerative diseases is associated with the rates of senescent cell generation and clearance within the brain. Given the role of microglia in eliminating senescent cells, the accumulation of senescent microglia may lead to the acceleration of brain aging, contributing to inflammaging and increased vulnerability to neurodegenerative diseases. In this review, we propose the idea that the senescence of microglia, which is notably vulnerable to aging, could potentially serve as a central catalyst in the progression of neurodegenerative diseases. The senescent microglia are emerging as a promising target for mitigating neurodegenerative diseases.
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Affiliation(s)
- Chan Rim
- Department of Pharmacology, Research Institute for Basic Medical Science, School of Medicine, CHA University, CHA Bio Complex, 335 Pangyo, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, Republic of Korea
| | - Min-Jung You
- Department of Pharmacology, Research Institute for Basic Medical Science, School of Medicine, CHA University, CHA Bio Complex, 335 Pangyo, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, Republic of Korea
| | - Minyeop Nahm
- Dementia Research Group, Korea Brain Research Institute, Daegu, Republic of Korea
| | - Min-Soo Kwon
- Department of Pharmacology, Research Institute for Basic Medical Science, School of Medicine, CHA University, CHA Bio Complex, 335 Pangyo, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, Republic of Korea.
- Brainimmunex Inc., 26 Yatap-ro, Bundang-gu, Seongnam-si, Gyeonggi-do, 13522, Republic of Korea.
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3
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Bolandghamat S, Behnam‐Rassouli M. Iron role paradox in nerve degeneration and regeneration. Physiol Rep 2024; 12:e15908. [PMID: 38176709 PMCID: PMC10766496 DOI: 10.14814/phy2.15908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 12/02/2023] [Accepted: 12/14/2023] [Indexed: 01/06/2024] Open
Abstract
Iron accumulates in the neural tissue during peripheral nerve degeneration. Some studies have already been suggested that iron facilitates Wallerian degeneration (WD) events such as Schwann cell de-differentiation. On the other hand, intracellular iron levels remain elevated during nerve regeneration and gradually decrease. Iron enhances Schwann cell differentiation and axonal outgrowth. Therefore, there seems to be a paradox in the role of iron during nerve degeneration and regeneration. We explain this contradiction by suggesting that the increase in intracellular iron concentration during peripheral nerve degeneration is likely to prepare neural cells for the initiation of regeneration. Changes in iron levels are the result of changes in the expression of iron homeostasis proteins. In this review, we will first discuss the changes in the iron/iron homeostasis protein levels during peripheral nerve degeneration and regeneration and then explain how iron is related to nerve regeneration. This data may help better understand the mechanisms of peripheral nerve repair and find a solution to prevent or slow the progression of peripheral neuropathies.
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Affiliation(s)
- Samira Bolandghamat
- Department of Biology, Faculty of ScienceFerdowsi University of MashhadMashhadIran
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4
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Agas A, Ravula AR, Ma X, Cheng Y, Belfield KD, Haorah J. Hemolytic iron regulation in traumatic brain injury and alcohol use. Alcohol 2023; 109:1-12. [PMID: 36690222 PMCID: PMC10175116 DOI: 10.1016/j.alcohol.2023.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 12/18/2022] [Accepted: 01/03/2023] [Indexed: 01/22/2023]
Abstract
Hemorrhage is a major component of traumatic brain injury (TBI). Red blood cells, accumulated at the hemorrhagic site, undergo hemolysis upon energy depletion and release free iron into the central nervous system. This iron must be managed to prevent iron neurotoxicity and ferroptosis. As prior alcohol consumption is often associated with TBI, we examined iron regulation in a rat model of chronic alcohol feeding subjected to fluid percussion-induced TBI. We found that alcohol consumption prior to TBI altered the expression profiles of the lipocalin 2/heme oxygenase 1/ferritin iron management system. Notably, unlike TBI alone, TBI following chronic alcohol consumption sustained the expression of all three regulatory proteins for 1, 3, and 7 days post-injury. In addition, alcohol significantly affected TBI-induced expression of ferritin light chain at 3 days post-injury. We also found that alcohol exacerbated TBI-induced activation of microglia at 7 days post-injury. Finally, we propose that microglia may also play a role in iron management through red blood cell clearance.
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Affiliation(s)
- Agnieszka Agas
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States.
| | - Arun Reddy Ravula
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States
| | - Xiaotang Ma
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States
| | - Yiming Cheng
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States
| | - Kevin D Belfield
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ, United States
| | - James Haorah
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States
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5
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Smith AN, Shaughness M, Collier S, Hopkins D, Byrnes KR. Therapeutic targeting of microglia mediated oxidative stress after neurotrauma. Front Med (Lausanne) 2022; 9:1034692. [PMID: 36405593 PMCID: PMC9671221 DOI: 10.3389/fmed.2022.1034692] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 10/12/2022] [Indexed: 10/06/2023] Open
Abstract
Inflammation is a primary component of the central nervous system injury response. Traumatic brain and spinal cord injury are characterized by a pronounced microglial response to damage, including alterations in microglial morphology and increased production of reactive oxygen species (ROS). The acute activity of microglia may be beneficial to recovery, but continued inflammation and ROS production is deleterious to the health and function of other cells. Microglial nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX), mitochondria, and changes in iron levels are three of the most common sources of ROS. All three play a significant role in post-traumatic brain and spinal cord injury ROS production and the resultant oxidative stress. This review will evaluate the current state of therapeutics used to target these avenues of microglia-mediated oxidative stress after injury and suggest avenues for future research.
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Affiliation(s)
- Austin N. Smith
- Neuroscience Program, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Michael Shaughness
- Neuroscience Program, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Sean Collier
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Deanna Hopkins
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Kimberly R. Byrnes
- Neuroscience Program, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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6
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Ravanfar P, Syeda WT, Jayaram M, Rushmore RJ, Moffat B, Lin AP, Lyall AE, Merritt AH, Yaghmaie N, Laskaris L, Luza S, Opazo CM, Liberg B, Chakravarty MM, Devenyi GA, Desmond P, Cropley VL, Makris N, Shenton ME, Bush AI, Velakoulis D, Pantelis C. In Vivo 7-Tesla MRI Investigation of Brain Iron and Its Metabolic Correlates in Chronic Schizophrenia. SCHIZOPHRENIA (HEIDELBERG, GERMANY) 2022; 8:86. [PMID: 36289238 PMCID: PMC9605948 DOI: 10.1038/s41537-022-00293-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Brain iron is central to dopaminergic neurotransmission, a key component in schizophrenia pathology. Iron can also generate oxidative stress, which is one proposed mechanism for gray matter volume reduction in schizophrenia. The role of brain iron in schizophrenia and its potential link to oxidative stress has not been previously examined. In this study, we used 7-Tesla MRI quantitative susceptibility mapping (QSM), magnetic resonance spectroscopy (MRS), and structural T1 imaging in 12 individuals with chronic schizophrenia and 14 healthy age-matched controls. In schizophrenia, there were higher QSM values in bilateral putamen and higher concentrations of phosphocreatine and lactate in caudal anterior cingulate cortex (caCC). Network-based correlation analysis of QSM across corticostriatal pathways as well as the correlation between QSM, MRS, and volume, showed distinct patterns between groups. This study introduces increased iron in the putamen in schizophrenia in addition to network-wide disturbances of iron and metabolic status.
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Affiliation(s)
- Parsa Ravanfar
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia.
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
| | - Warda T Syeda
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia
| | - Mahesh Jayaram
- Department of Psychiatry, The University of Melbourne and Melbourne Health, Parkville, Australia
| | - R Jarrett Rushmore
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
- Center for Morphometric Analysis (CMA), Massachusetts General Hospital, Charlestown, MA, USA
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, USA
| | - Bradford Moffat
- Melbourne Brain Centre Imaging Unit, Department of Radiology, University of Melbourne, Parkville, VIC, Australia
| | - Alexander P Lin
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
- Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Amanda E Lyall
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
- Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Antonia H Merritt
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia
| | - Negin Yaghmaie
- Melbourne Brain Centre Imaging Unit, Department of Radiology, University of Melbourne, Parkville, VIC, Australia
- Department of Biomedical Engineering, The University of Melbourne, Parkville, VIC, Australia
| | - Liliana Laskaris
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia
| | - Sandra Luza
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia
- Melbourne Dementia Research Centre, The Florey Institute of Neuroscience & Mental Health, and The University of Melbourne, Parkville, VIC, Australia
| | - Carlos M Opazo
- Melbourne Dementia Research Centre, The Florey Institute of Neuroscience & Mental Health, and The University of Melbourne, Parkville, VIC, Australia
| | - Benny Liberg
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - M Mallar Chakravarty
- Cerebral Imaging Center, Douglas Research Centre, Montreal, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
- Department of Biomedical Engineering, McGill University, Montreal, QC, Canada
| | - Gabriel A Devenyi
- Cerebral Imaging Center, Douglas Research Centre, Montreal, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Patricia Desmond
- Department of Radiology, Royal Melbourne Hospital, University of Melbourne, Parkville, VIC, Australia
| | - Vanessa L Cropley
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia
| | - Nikos Makris
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
- Center for Morphometric Analysis (CMA), Massachusetts General Hospital, Charlestown, MA, USA
| | - Martha E Shenton
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Ashley I Bush
- Melbourne Dementia Research Centre, The Florey Institute of Neuroscience & Mental Health, and The University of Melbourne, Parkville, VIC, Australia
| | - Dennis Velakoulis
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia
- Neuropsychiatry, The Royal Melbourne Hospital, Parkville, VIC, Australia
| | - Christos Pantelis
- Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Carlton South, VIC, Australia.
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia.
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7
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Rahimian R, Belliveau C, Chen R, Mechawar N. Microglial Inflammatory-Metabolic Pathways and Their Potential Therapeutic Implication in Major Depressive Disorder. Front Psychiatry 2022; 13:871997. [PMID: 35782423 PMCID: PMC9245023 DOI: 10.3389/fpsyt.2022.871997] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 05/23/2022] [Indexed: 12/19/2022] Open
Abstract
Increasing evidence supports the notion that neuroinflammation plays a critical role in the etiology of major depressive disorder (MDD), at least in a subset of patients. By virtue of their capacity to transform into reactive states in response to inflammatory insults, microglia, the brain's resident immune cells, play a pivotal role in the induction of neuroinflammation. Experimental studies have demonstrated the ability of microglia to recognize pathogens or damaged cells, leading to the activation of a cytotoxic response that exacerbates damage to brain cells. However, microglia display a wide range of responses to injury and may also promote resolution stages of inflammation and tissue regeneration. MDD has been associated with chronic priming of microglia. Recent studies suggest that altered microglial morphology and function, caused either by intense inflammatory activation or by senescence, may contribute to depression and associated impairments in neuroplasticity. In this context, modifying microglia phenotype by tuning inflammatory pathways might have important translational relevance to harness neuroinflammation in MDD. Interestingly, it was recently shown that different microglial phenotypes are associated with distinct metabolic pathways and analysis of the underlying molecular mechanisms points to an instrumental role for energy metabolism in shaping microglial functions. Here, we review various canonical pro-inflammatory, anti-inflammatory and metabolic pathways in microglia that may provide new therapeutic opportunities to control neuroinflammation in brain disorders, with a strong focus on MDD.
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Affiliation(s)
- Reza Rahimian
- Douglas Mental Health University Institute, McGill Group for Suicide Studies, Verdun, QC, Canada
| | - Claudia Belliveau
- Douglas Mental Health University Institute, McGill Group for Suicide Studies, Verdun, QC, Canada.,Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Rebecca Chen
- Douglas Mental Health University Institute, McGill Group for Suicide Studies, Verdun, QC, Canada.,Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Naguib Mechawar
- Douglas Mental Health University Institute, McGill Group for Suicide Studies, Verdun, QC, Canada.,Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada.,Department of Psychiatry, McGill University, Montreal, QC, Canada
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8
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Guo Z, Long L, Qiu W, Lu T, Zhang L, Shu Y, Zhang K, Fang L, Chen S. The Distributional Characteristics of Multiple Sclerosis Lesions on Quantitative Susceptibility Mapping and Their Correlation With Clinical Severity. Front Neurol 2021; 12:647519. [PMID: 34305779 PMCID: PMC8299522 DOI: 10.3389/fneur.2021.647519] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 06/08/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Multiple sclerosis (MS) patients have a wide spectrum of severity and responses to therapy; the personalization of treatment relies on sensitive and specific biomarkers. Previous studies have suggested that susceptibility contrast in demyelinated plaques is associated with iron-related pathology in multiple sclerosis which may indicate clinical severity. The aims of this study were to characterize the spatial distribution of MS lesions with different iron patterns by using quantitative susceptibility mapping and to explore neuroradiological findings that correlate with poor clinical outcome. Methods: Twenty-six patients with relapsing-remitting MS [14 men, 12 women; mean age, 29 ± 8 (standard deviation) years; age range, 21-52 years] were included in this study. Differences in lesion number, T2 volume, and susceptibility were compared among lesions subcategorized by location and by the presence or absence of a hyperintense rim on quantitative susceptibility mapping. Associations between these imaging features and clinical outcomes including Expanded Disability Status Scale scores and annual relapse rates were investigated. Results: A total of 811 unifocal MS lesions were included, and their QSM patterns were nodular hyperintensity with no rim (rim-, 540, 67%) or with a hyperintense rim on the edge (rim+, 172, 21%) and nodular isointensity (99, 12%). Rim+ lesions had significantly larger volume (115 ± 142 vs. 166 ± 185 mm3, p < 0.001) and lower susceptibility (4 ± 15 vs. 8 ± 16 ppb, p < 0.05) than rim- lesions. More rim+ lesions were found in periventricular areas [median, 45%; interquartile range (IQR), 36%], whereas a larger proportion of rim- lesions were distributed in juxtacortical (median, 32%; IQR, 21%) and deep white matter (median, 38%; IQR, 22%) areas. The annual relapse rate was positively correlated with the proportion of periventricular rim+ lesions (p < 0.001, r = 0.65) and the proportion of subtentorial rim+ lesions (p < 0.05, r = 0.40). Additionally, a significant association was found between the burden of periventricular rim+ lesions (β = 0.64, p < 0.001) and the burden of subtentorial rim- lesions (β = 0.36, p < 0.05). Conclusions: A high number or lesion burden of periventricular rim+ lesions or subtentorial lesions is associated with frequent clinical relapses.
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Affiliation(s)
- Zhuoxin Guo
- Department of Radiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Liu Long
- Department of Radiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Wei Qiu
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Tingting Lu
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Lina Zhang
- Department of Radiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Yaqing Shu
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Ke Zhang
- Department of Radiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Ling Fang
- Department of Radiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Shaoqiong Chen
- Department of Radiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
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9
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Amaral EP, Vinhaes CL, Oliveira-de-Souza D, Nogueira B, Akrami KM, Andrade BB. The Interplay Between Systemic Inflammation, Oxidative Stress, and Tissue Remodeling in Tuberculosis. Antioxid Redox Signal 2021; 34:471-485. [PMID: 32559410 PMCID: PMC8020551 DOI: 10.1089/ars.2020.8124] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Significance: Excessive and prolonged proinflammatory responses are associated with oxidative stress, which is commonly observed during chronic tuberculosis (TB). Such condition favors tissue destruction and consequently bacterial spread. A tissue remodeling program is also triggered in chronically inflamed sites, facilitating a wide spectrum of clinical manifestations. Recent Advances: Since persistent and exacerbated oxidative stress responses have been associated with severe pathology, a number of studies have suggested that the inhibition of this augmented stress response by improving host antioxidant status may represent a reasonable strategy to ameliorate tissue damage in TB. Critical Issues: This review summarizes the interplay between oxidative stress, systemic inflammation and tissue remodeling, and its consequences in promoting TB disease. We emphasize the most important mechanisms associated with stress responses that contribute to the progression of TB. We also point out important host immune components that may influence the exacerbation of cellular stress and the subsequent tissue injury. Future Directions: Further research should reveal valuable targets for host-directed therapy of TB, preventing development of severe immunopathology and disease progression. Antioxid. Redox Signal. 34, 471-485.
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Affiliation(s)
- Eduardo P Amaral
- Immunobiology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Caian L Vinhaes
- Laboratório de Inflamação e Biomarcadores, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.,Multinational Organization Network Sponsoring Translational and Epidemiological Research (MONSTER) Initiative, Salvador, Brazil.,Curso de Medicina, Faculdade de Tecnologia e Ciências (FTC), Salvador, Brazil
| | - Deivide Oliveira-de-Souza
- Laboratório de Inflamação e Biomarcadores, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.,Multinational Organization Network Sponsoring Translational and Epidemiological Research (MONSTER) Initiative, Salvador, Brazil.,Curso de Medicina, Faculdade de Tecnologia e Ciências (FTC), Salvador, Brazil
| | - Betania Nogueira
- Multinational Organization Network Sponsoring Translational and Epidemiological Research (MONSTER) Initiative, Salvador, Brazil.,Curso de Medicina, Faculdade de Tecnologia e Ciências (FTC), Salvador, Brazil.,Faculdade de Medicina, Universidade Federal da Bahia, Salvador, Brazil
| | - Kevan M Akrami
- Multinational Organization Network Sponsoring Translational and Epidemiological Research (MONSTER) Initiative, Salvador, Brazil.,Faculdade de Medicina, Universidade Federal da Bahia, Salvador, Brazil.,Division of Infectious Diseases and Pulmonary Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, California, USA
| | - Bruno B Andrade
- Laboratório de Inflamação e Biomarcadores, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.,Multinational Organization Network Sponsoring Translational and Epidemiological Research (MONSTER) Initiative, Salvador, Brazil.,Curso de Medicina, Faculdade de Tecnologia e Ciências (FTC), Salvador, Brazil.,Wellcome Centre for Infectious Disease Research in Africa, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa.,Division of Infectious Diseases, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.,Universidade Salvador (UNIFACS), Laureate Universities, Salvador, Brazil.,Escola Bahiana de Medicina e Saúde Pública (EBMSP), Salvador, Brazil
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10
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Iron-Storage Protein Ferritin Is Upregulated in Endometriosis and Iron Overload Contributes to a Migratory Phenotype. Biomedicines 2020; 8:biomedicines8110454. [PMID: 33121166 PMCID: PMC7694081 DOI: 10.3390/biomedicines8110454] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/13/2020] [Accepted: 10/26/2020] [Indexed: 02/07/2023] Open
Abstract
High levels of iron in the peritoneal cavity during menstruation have been implicated in the pathogenesis of endometriosis. However, whether iron directly affects the growth or migration of human endometriotic cells is poorly understood. This study demonstrated the presence of increased levels of the iron storage protein, ferritin, in the endometriotic tissues of patients with endometriosis. Furthermore, iron treatment stimulated the migration and epithelial–mesenchymal transition (EMT), but not growth, of 12Z human endometriotic cells. The expression of matrix metalloproteinase (MMP)-2/-9 was markedly increased through iron treatment in 12Z cells. Interestingly, intracellular reactive oxygen species (ROS) levels were significantly increased by iron in 12Z cells, and N-acetyl-L-cysteine significantly reduced iron-induced migration and MMP-2/-9 expression. Additionally, iron stimulated the activation of the NFκB pathway, and the activation was associated with iron-induced migration and MMP-2/-9 expression in 12Z cells. Moreover, iron markedly increased EMT and MMP-2/-9 expression in endometriotic lesions in an endometriosis mouse model. Taken together, these results suggest that iron may contribute to the migration abilities of human endometriotic cells via MMP expression through the ROS–NFκB pathway.
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11
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Miedema A, Wijering MHC, Eggen BJL, Kooistra SM. High-Resolution Transcriptomic and Proteomic Profiling of Heterogeneity of Brain-Derived Microglia in Multiple Sclerosis. Front Mol Neurosci 2020; 13:583811. [PMID: 33192299 PMCID: PMC7654237 DOI: 10.3389/fnmol.2020.583811] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 09/23/2020] [Indexed: 12/12/2022] Open
Abstract
Microglia are important for central nervous system (CNS) homeostasis and first to respond to tissue damage and perturbations. Microglia are heterogeneous cells; in case of pathology, microglia adopt a range of phenotypes with altered functions. However, how these different microglia subtypes are implicated in CNS disease is largely unresolved. Multiple sclerosis (MS) is a chronic demyelinating disease of the CNS, characterized by inflammation and axonal degeneration, ultimately leading to neurological decline. One way microglia are implicated in MS is through stimulation of remyelination. They facilitate efficient remyelination by phagocytosis of myelin debris. In addition, microglia recruit oligodendrocyte precursor cells (OPCs) to demyelinated areas and stimulate remyelination. The development of high-resolution technologies to profile individual cells has greatly contributed to our understanding of microglia heterogeneity and function under normal and pathological conditions. Gene expression profiling technologies have evolved from whole tissue RNA sequencing toward single-cell or nucleus sequencing. Single microglia proteomic profiles are also increasingly generated, offering another layer of high-resolution data. Here, we will review recent studies that have employed these technologies in the context of MS and their respective advantages and disadvantages. Moreover, recent developments that allow for (single) cell profiling while retaining spatial information and tissue context will be discussed.
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Affiliation(s)
- Anneke Miedema
- Section Molecular Neurobiology, Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Marion H C Wijering
- Section Molecular Neurobiology, Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Bart J L Eggen
- Section Molecular Neurobiology, Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Susanne M Kooistra
- Section Molecular Neurobiology, Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
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12
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Lee NJ, Ha SK, Sati P, Absinta M, Nair G, Luciano NJ, Leibovitch EC, Yen CC, Rouault TA, Silva AC, Jacobson S, Reich DS. Potential role of iron in repair of inflammatory demyelinating lesions. J Clin Invest 2020; 129:4365-4376. [PMID: 31498148 DOI: 10.1172/jci126809] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 07/16/2019] [Indexed: 12/20/2022] Open
Abstract
Inflammatory destruction of iron-rich myelin is characteristic of multiple sclerosis (MS). Although iron is needed for oligodendrocytes to produce myelin during development, its deposition has also been linked to neurodegeneration and inflammation, including in MS. We report perivascular iron deposition in multiple sclerosis lesions that was mirrored in 72 lesions from 13 marmosets with experimental autoimmune encephalomyelitis. Iron accumulated mainly inside microglia/macrophages from 6 weeks after demyelination. Consistently, expression of transferrin receptor, the brain's main iron-influx protein, increased as lesions aged. Iron was uncorrelated with inflammation and postdated initial demyelination, suggesting that iron is not directly pathogenic. Iron homeostasis was at least partially restored in remyelinated, but not persistently demyelinated, lesions. Taken together, our results suggest that iron accumulation in the weeks after inflammatory demyelination may contribute to lesion repair rather than inflammatory demyelination per se.
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Affiliation(s)
- Nathanael J Lee
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA.,Department of Neuroscience, Georgetown University Medical Center, Georgetown University, Washington, District of Columbia, USA
| | - Seung-Kwon Ha
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Pascal Sati
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Martina Absinta
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Govind Nair
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Nicholas J Luciano
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Emily C Leibovitch
- Viral Immunology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Cecil C Yen
- Cerebral Microcirculation Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Tracey A Rouault
- Section on Human Iron Metabolism, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Afonso C Silva
- Cerebral Microcirculation Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Steven Jacobson
- Viral Immunology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Daniel S Reich
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
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13
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Recent advances in the mechanisms of neuroinflammation and their roles in neurodegeneration. Neurochem Int 2018; 120:13-20. [PMID: 30016687 DOI: 10.1016/j.neuint.2018.07.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 06/07/2018] [Accepted: 07/13/2018] [Indexed: 12/11/2022]
Abstract
Neuroinflammation is associated with the pathogenesis of many neurological disorders including Parkinson's disease, Alzheimer's disease, Amyotrophic lateral sclerosis and Huntington disease. Current studies in this area have advanced the mechanism of neuroinflammation and its role in neurodegeneration. Studies from epidemiologic, clinical and animal models also contributed in the various new mechanisms of neuroinflammation. In this line, activation of monocytes is an important emerging mechanism that has a, profound role in neuroinflammation and neurodegeneration. Ion channels, matrix metalloproteases and microRNAs are also found to be the key players in the pathogenesis of neuroinflammation. In particular, microRNA-32 regulates microglia-mediated neuroinflammation and thus neurodegeneration. Notably, some important studies describe the role of Th17 cells in neuroinflammation, but, very little knowledge is available about their mechanism of action. Particularly, the role of autophagy gets emphasized, which plays a very critical role in protein aggregation and neurodegeneration. In this review, we highlight and discuss the mechanisms of these mediators of inflammation by which they contribute to the disease progression. In conclusion, we focus on the various newer molecular mechanisms that are associated with the basic understanding of neuroinflammation in neurodegeneration.
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14
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Schmidt KE, Kuepper JM, Schumak B, Alferink J, Hofmann A, Howland SW, Rénia L, Limmer A, Specht S, Hoerauf A. Doxycycline inhibits experimental cerebral malaria by reducing inflammatory immune reactions and tissue-degrading mediators. PLoS One 2018; 13:e0192717. [PMID: 29438386 PMCID: PMC5811026 DOI: 10.1371/journal.pone.0192717] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 01/29/2018] [Indexed: 12/22/2022] Open
Abstract
Malaria ranks among the most important infectious diseases worldwide and affects mostly people living in tropical countries. Mechanisms involved in disease progression are still not fully understood and specific treatments that might interfere with cerebral malaria (CM) are limited. Here we show that administration of doxycycline (DOX) prevented experimental CM (ECM) in Plasmodium berghei ANKA (PbA)-infected C57BL/6 wildtype (WT) mice in an IL-10-independent manner. DOX-treated mice showed an intact blood-brain barrier (BBB) and attenuated brain inflammation. Importantly, if WT mice were infected with a 20-fold increased parasite load, they could be still protected from ECM if they received DOX from day 4-6 post infection, despite similar parasitemia compared to control-infected mice that did not receive DOX and developed ECM. Infiltration of T cells and cytotoxic responses were reduced in brains of DOX-treated mice. Analysis of brain tissue by RNA-array revealed reduced expression of chemokines and tumour necrosis factor (TNF) in brains of DOX-treated mice. Furthermore, DOX-administration resulted in brains of the mice in reduced expression of matrix metalloproteinase 2 (MMP2) and granzyme B, which are both factors associated with ECM pathology. Systemic interferon gamma production was reduced and activated peripheral T cells accumulated in the spleen in DOX-treated mice. Our results suggest that DOX targeted inflammatory processes in the central nervous system (CNS) and prevented ECM by impaired brain access of effector T cells in addition to its anti-parasitic effect, thereby expanding the understanding of molecular events that underlie DOX-mediated therapeutic interventions.
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Affiliation(s)
- Kim E. Schmidt
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Janina M. Kuepper
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Beatrix Schumak
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
- * E-mail:
| | - Judith Alferink
- Department of Psychiatry and Psychotherapy, University Hospital Muenster, Muenster, Germany
| | - Andrea Hofmann
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Shanshan W. Howland
- Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Laurent Rénia
- Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Andreas Limmer
- Clinic for Anaesthesiology and Intensive Care, University Hospital Essen, Essen, Germany
- Institutes of Molecular Medicine and Experimental Immunology, University Hospital Bonn, Bonn, Germany
| | - Sabine Specht
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
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15
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Mairuae N, Cheepsunthorn P. Valproic acid attenuates nitric oxide and interleukin-1β production in lipopolysaccharide-stimulated iron-rich microglia. Biomed Rep 2018. [PMID: 29541456 DOI: 10.3892/br.2018.1062] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Iron accumulation in activated microglia has been consistently reported in neurodegenerative diseases. Previous results suggest that these cells facilitate neuroinflammation leading to neuronal cell death. Therefore, chemical compounds that alleviate the activation of iron-rich microglia may result in neuroprotection. In the present study, the effect of valproic acid (VPA) on microglial activation under iron-rich conditions was investigated. BV-2 microglial cells were exposed to lipopolysaccharide (LPS; 1 µg/ml) and iron (300 µg/ml) with or without VPA (1.6 mM). The results demonstrated that VPA attenuated the activation of iron-rich BV2 cells induced by LPS by down-regulating the mRNA expression of inducible nitric oxide (NO) synthase and interleukin 1β (IL-1β; P<0.01), to ultimately reduce the production of NO and IL-1β (P<0.01). These events were accompanied by an attenuation in the nuclear translocation of nuclear factor-κB p65 subunit (P<0.01). These findings suggest that VPA may be therapeutically useful for attenuating the activation of iron-rich microglia.
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Affiliation(s)
- Nootchanat Mairuae
- Biomedical Research Unit, Faculty of Medicine, Mahasarakham University, Maha Sarakham 44000, Thailand
| | - Poonlarp Cheepsunthorn
- Department of Anatomy, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
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16
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Peters DG, Pollack AN, Cheng KC, Sun D, Saido T, Haaf MP, Yang QX, Connor JR, Meadowcroft MD. Dietary lipophilic iron alters amyloidogenesis and microglial morphology in Alzheimer's disease knock-in APP mice. Metallomics 2018; 10:426-443. [PMID: 29424844 DOI: 10.1039/c8mt00004b] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized pathologically by amyloid beta (Aβ) deposition, microgliosis, and iron dyshomeostasis. Increased labile iron due to homeostatic dysregulation is believed to facilitate amyloidogenesis. Free iron is incorporated into aggregating amyloid peptides during Aβ plaque formation and increases potential for oxidative stress surrounding plaques. The goal of this work was to observe how brain iron levels temporally influence Aβ plaque formation, plaque iron concentration, and microgliosis. We fed humanized APPNL-F and APPNL-G-F knock-in mice lipophilic iron compound 3,5,5-trimethylhexanoyl ferrocene (TMHF) and iron deficient diets for twelve months. TMHF elevated brain iron by 22% and iron deficiency decreased brain iron 21% relative to control diet. Increasing brain iron with TMHF accelerated plaque formation, increased Aβ staining, and increased senile morphology of amyloid plaques. Increased brain iron was associated with increased plaque-iron loading and microglial iron inclusions. TMHF decreased IBA1+ microglia branch length while increasing roundness indicative of microglial activation. This body of work suggests that increasing mouse brain iron with TMHF potentiates a more human-like Alzheimer's disease phenotype with iron integration into Aβ plaques and associated microgliosis.
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Affiliation(s)
- Douglas G Peters
- Department of Neurosurgery, The Pennsylvania State University - College of Medicine, 500 University Drive, Hershey, Pennsylvania 17033, USA and Department of Neural and Behavioral Science, The Pennsylvania State University - College of Medicine, Hershey, Pennsylvania, USA
| | - Alexis N Pollack
- Department of Neurosurgery, The Pennsylvania State University - College of Medicine, 500 University Drive, Hershey, Pennsylvania 17033, USA
| | - Keith C Cheng
- Department of Pathology (Gittlen Cancer Research Institute), The Pennsylvania State University - College of Medicine, Hershey, Pennsylvania, USA
| | - Dongxiao Sun
- Department of Pharmacology, The Pennsylvania State University - College of Medicine, Hershey, Pennsylvania, USA
| | - Takaomi Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Brain Science Institute, Wakō-shi, Saitama-ken, Japan
| | - Michael P Haaf
- Department of Chemistry, Ithaca College, Ithaca, New York, USA
| | - Qing X Yang
- Department of Radiology (Center for NMR Research), The Pennsylvania State University - College of Medicine, Hershey, Pennsylvania, USA
| | - James R Connor
- Department of Neurosurgery, The Pennsylvania State University - College of Medicine, 500 University Drive, Hershey, Pennsylvania 17033, USA
| | - Mark D Meadowcroft
- Department of Neurosurgery, The Pennsylvania State University - College of Medicine, 500 University Drive, Hershey, Pennsylvania 17033, USA and Department of Radiology (Center for NMR Research), The Pennsylvania State University - College of Medicine, Hershey, Pennsylvania, USA
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17
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Nixon AM, Neely E, Simpson IA, Connor JR. The role of HFE genotype in macrophage phenotype. J Neuroinflammation 2018; 15:30. [PMID: 29391061 PMCID: PMC5796391 DOI: 10.1186/s12974-018-1057-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 01/03/2018] [Indexed: 12/14/2022] Open
Abstract
Background Iron regulation is essential for cellular energy production. Loss of cellular iron homeostasis has critical implications for both normal function and disease progression. The H63D variant of the HFE gene is the most common gene variant in Caucasians. The resulting mutant protein alters cellular iron homeostasis and is associated with a number of neurological diseases and cancer. In the brain, microglial and infiltrating macrophages are critical to maintaining iron homeostasis and modulating inflammation associated with the pathogenic process in multiple diseases. This study addresses whether HFE genotype affects macrophage function and the implications of these findings for disease processes. Methods Bone marrow macrophages were isolated from wildtype and H67D HFE knock-in mice. The H67D gene variant in mice is the human equivalent of the H63D variant. Upon differentiation, the macrophages were used to analyze iron regulatory proteins, cellular iron release, migration, phagocytosis, and cytokine expression. Results The results of this study demonstrate that the H67D HFE genotype significantly impacts a number of critical macrophage functions. Specifically, fundamental activities such as proliferation in response to iron exposure, L-ferritin expression in response to iron loading, secretion of BMP6 and cytokines, and migration and phagocytic activity were all found to be impacted by genotype. Furthermore, we demonstrated that exposure to apo-Tf (iron-poor transferrin) can increase the release of iron from macrophages. In normal conditions, 70% of circulating transferrin is unsaturated. Therefore, the ability of apo-Tf to induce iron release could be a major regulatory mechanism for iron release from macrophages. Conclusions These studies demonstrate that the HFE genotype impacts fundamental components of macrophage phenotype that could alter their role in degenerative and reparative processes in neurodegenerative disorders.
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Affiliation(s)
- Anne M Nixon
- Department of Neurosurgery, The Pennsylvania State University College of Medicine, M.S. Hershey Medical Center, Hershey, PA, 17033, USA.
| | - Elizabeth Neely
- Department of Neurosurgery, The Pennsylvania State University College of Medicine, M.S. Hershey Medical Center, Hershey, PA, 17033, USA
| | - Ian A Simpson
- Department of Neural and Behavior Science, The Pennsylvania State University College of Medicine, M.S. Hershey Medical Center, Hershey, 17033, PA, USA
| | - James R Connor
- Department of Neurosurgery, The Pennsylvania State University College of Medicine, M.S. Hershey Medical Center, Hershey, PA, 17033, USA
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18
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Klocke C, Allen JL, Sobolewski M, Mayer-Pröschel M, Blum JL, Lauterstein D, Zelikoff JT, Cory-Slechta DA. Neuropathological Consequences of Gestational Exposure to Concentrated Ambient Fine and Ultrafine Particles in the Mouse. Toxicol Sci 2018; 156:492-508. [PMID: 28087836 DOI: 10.1093/toxsci/kfx010] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Increasing evidence indicates that the central nervous system (CNS) is a target of air pollution. We previously reported that postnatal exposure of mice to concentrated ambient ultrafine particles (UFP; ≤100 nm) via the University of Rochester HUCAPS system during a critical developmental window of CNS development, equivalent to human 3rd trimester, produced male-predominant neuropathological and behavioral characteristics common to multiple neurodevelopmental disorders, including autism spectrum disorder (ASD), in humans. The current study sought to determine whether vulnerability to fine (≤2.5 μm) and UFP air pollution exposure extends to embryonic periods of brain development in mice, equivalent to human 1st and 2nd trimesters. Pregnant mice were exposed 6 h/day from gestational days (GDs) 0.5-16.5 using the New York University VACES system to concentrated ambient fine/ultrafine particles at an average concentration of 92.69 μg/m3 over the course of the exposure period. At postnatal days (PNDs) 11-15, neuropathological consequences were characterized. Gestational air pollution exposures produced ventriculomegaly, increased corpus callosum (CC) area and reduced hippocampal area in both sexes. Both sexes demonstrated CC hypermyelination and increased microglial activation and reduced total CC microglia number. Analyses of iron deposition as a critical component of myelination revealed increased iron deposition in the CC of exposed female offspring, but not in males. These findings demonstrate that vulnerability of the brain to air pollution extends to gestation and produces features of several neurodevelopmental disorders in both sexes. Further, they highlight the importance of the commonalities of components of particulate matter exposures as a source of neurotoxicity and common CNS alterations.
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Affiliation(s)
| | | | | | - Margot Mayer-Pröschel
- Department of Biomedical Genetics, University of Rochester School of Medicine, Rochester, New York 14642
| | - Jason L Blum
- Department of Environmental Medicine, New York University School of Medicine, Tuxedo, New York 10987
| | - Dana Lauterstein
- Department of Environmental Medicine, New York University School of Medicine, Tuxedo, New York 10987
| | - Judith T Zelikoff
- Department of Environmental Medicine, New York University School of Medicine, Tuxedo, New York 10987
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19
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Meng FX, Hou JM, Sun TS. In vivo evaluation of microglia activation by intracranial iron overload in central pain after spinal cord injury. J Orthop Surg Res 2017; 12:75. [PMID: 28521818 PMCID: PMC5437601 DOI: 10.1186/s13018-017-0578-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 03/24/2017] [Indexed: 11/23/2022] Open
Abstract
Background Central pain (CP) is a common clinical problem in patients with spinal cord injury (SCI). Recent studies found the pathogenesis of CP was related to the remodeling of the brain. We investigate the roles of iron overload and subsequent microglia activate in the remodeling of the brain after SCI. Methods An SCI-induced CP model was established in Sprague-Dawley rats that were randomly assigned to SCI, sham operation, deferoxamine (DFX), minocycline, and nitric oxide synthase inhibitor treatment groups. At 12 weeks, pain behavior and thermal pain threshold were evaluated in each group, and iron transferrin receptor (TfR)1 and ferritin (Fn) mRNA, as well as iron-regulatory protein (IRP)1, FN, lactoferrin, and nuclear factor (NF)-κB protein levels in the rat brains were measured. Microglia proliferation and differentiation and IRP1 expression were evaluated by immunohistochemistry. Results Autophagy was observed in rats after SCI, accompanied by reduced latency of thermal pain, increased iron content and IRP1 and NF-κB levels in the hindlimb sensory area, hippocampus, and thalamus, and decreased Fn levels in the hindlimb sensory area. TfR1 mRNA expression was upregulated in activated microglia. Treatment with an iron-chelating agent, or inhibitors of nitric oxide synthase or microglia suppressed microglia proliferation. Conclusions SCI may induce intracranial iron overload, which activates microglia via NF-κB signaling. Microglia secrete inflammatory factors that induce neuronal damage and lead to CP. Treatment with an iron-chelating agent or NF-κB or microglia inhibitors can relieve CP resulting from SCI.
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Affiliation(s)
- Fan Xing Meng
- Third Military Medical University, No. 30 Gaotanyan Street, Chongqing, 400038, China.,Department of Orthopedics, Chinese PLA Army General Hospital, Dongcheng District, Nanmencang No. 5, Beijing, 100700, China
| | - Jing Ming Hou
- Department of Orthopedics, Chinese PLA Army General Hospital, Dongcheng District, Nanmencang No. 5, Beijing, 100700, China.,Department of Rehabilitation, Southwest Hospital, Third Military Medical University, No. 30 Gaotanyan Street, Chongqing, 400038, China
| | - Tian Sheng Sun
- Third Military Medical University, No. 30 Gaotanyan Street, Chongqing, 400038, China. suntiansheng-@163.com.,Department of Orthopedics, Chinese PLA Army General Hospital, Dongcheng District, Nanmencang No. 5, Beijing, 100700, China. suntiansheng-@163.com
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20
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Rosato-Siri MV, Marziali L, Guitart ME, Badaracco ME, Puntel M, Pitossi F, Correale J, Pasquini JM. Iron Availability Compromises Not Only Oligodendrocytes But Also Astrocytes and Microglial Cells. Mol Neurobiol 2017; 55:1068-1081. [DOI: 10.1007/s12035-016-0369-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 12/28/2016] [Indexed: 12/21/2022]
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21
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Pan K, Li X, Chen Y, Zhu D, Li Y, Tao G, Zuo Z. Deferoxamine pre-treatment protects against postoperative cognitive dysfunction of aged rats by depressing microglial activation via ameliorating iron accumulation in hippocampus. Neuropharmacology 2016; 111:180-194. [PMID: 27608977 DOI: 10.1016/j.neuropharm.2016.09.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 08/08/2016] [Accepted: 09/04/2016] [Indexed: 12/31/2022]
Abstract
Postoperative cognitive dysfunction (POCD) is a common complication of elderly patients after surgery. The mechanisms of POCD have not been clarified. Iron accumulation is a feature of neurodegeneration. Recent reports showed that iron content was increased with impaired cognition induced by surgery. We sought to investigate whether iron chelation would attenuate POCD. In this study, male aged (18 months) Sprague-Dawley rats received 100 mg/kg deferoxamine or saline solution (0.9%) for 6 days before exploratory laparotomy. Cognition was evaluated by Morris water maze before and after surgery. Additional rats received deferoxamine or saline were used to determine hippocampal iron content, iron transport-related proteins (transferrin receptor, divalent metal transporter 1, ferroportin 1 and hepcidin), oxidative stress, microglial activation and brain cell apoptosis. It was found that deferoxamine improved postoperative spatial memory in aged rats. Deferoxamine significantly reduced hippocampal iron concentration and ferritin. Surgery increased divalent metal transporter 1 and hepcidin, decreased transferrin receptor and ferroportin 1, and enhanced ferroportin 1 mRNA. However, deferoxamine reversed the changes of these proteins. Furthermore, deferoxamine sharply reduced the hippocampal reactive oxygen species, malondialdehyde concentration and OX-42 that is a marker of microglia, which might reduce postoperative brain cell apoptosis. This study showed that deferoxamine may improve postoperative cognition of aged rats by ameliorating oxidative stress induced by hippocampal iron accumulation, microglial activation and brain cell apoptosis. This study suggests a potential therapeutic method for reducing POCD.
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Affiliation(s)
- Ke Pan
- Department of Anesthesiology, Southwest Hospital, The Third Military Medical University, Chongqing, China; Department of Anesthesiology, No. 281 Hospital of People's Liberation Army, Hebei, China
| | - Xiaojun Li
- Department of Anesthesiology, Southwest Hospital, The Third Military Medical University, Chongqing, China
| | - Yan Chen
- Department of Anesthesiology, Southwest Hospital, The Third Military Medical University, Chongqing, China
| | - Dan Zhu
- Department of Anesthesiology, Southwest Hospital, The Third Military Medical University, Chongqing, China
| | - Yuping Li
- Department of Anesthesiology, Southwest Hospital, The Third Military Medical University, Chongqing, China
| | - Guocai Tao
- Department of Anesthesiology, Southwest Hospital, The Third Military Medical University, Chongqing, China.
| | - Zhiyi Zuo
- Department of Anesthesiology, University of Virginia, Charlottesville, VA, USA.
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22
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Camacho A, Simão M, Ea HK, Cohen-Solal M, Richette P, Branco J, Cancela ML. Iron overload in a murine model of hereditary hemochromatosis is associated with accelerated progression of osteoarthritis under mechanical stress. Osteoarthritis Cartilage 2016; 24:494-502. [PMID: 26403062 DOI: 10.1016/j.joca.2015.09.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 08/21/2015] [Accepted: 09/11/2015] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Hereditary hemochromatosis (HH) is a disease caused by mutations in the Hfe gene characterised by systemic iron overload and associated with an increased prevalence of osteoarthritis (OA) but the role of iron overload in the development of OA is still undefined. To further understand the molecular mechanisms involved we have used a murine model of HH and studied the progression of experimental OA under mechanical stress. DESIGN OA was surgically induced in the knee joints of 10-week-old C57BL6 (wild-type) mice and Hfe-KO mice. OA progression was assessed using histology, micro CT, gene expression and immunohistochemistry at 8 weeks after surgery. RESULTS Hfe-KO mice showed a systemic iron overload and an increased iron accumulation in the knee synovial membrane following surgery. The histological OA score was significantly higher in the Hfe-KO mice at 8 weeks after surgery. Micro CT study of the proximal tibia revealed increased subchondral bone volume and increased trabecular thickness. Gene expression and immunohistochemical analysis showed a significant increase in the expression of matrix metallopeptidase 3 (MMP-3) in the joints of Hfe-KO mice compared with control mice at 8 weeks after surgery. CONCLUSIONS HH was associated with an accelerated development of OA in mice. Our findings suggest that synovial iron overload has a definite role in the progression of HH-related OA.
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Affiliation(s)
- A Camacho
- Department of Orthopedics, Centro Hospitalar Lisboa Central, Lisboa, Portugal; PhD Program in Medicine, NOVA Medical School, University Nova de Lisboa, Lisbon, Portugal; Centre of Marine Sciences (CCMAR), University of Algarve, Faro, Portugal.
| | - M Simão
- Centre of Marine Sciences (CCMAR), University of Algarve, Faro, Portugal; PhD Program in Biomedical Sciences, University of Algarve, Faro, Portugal
| | - H-K Ea
- Inserm 1132, Hôpital Lariboisière, Paris, France; Université Paris Diderot, UFR médicale, Assistance Publique-Hôpitaux de Paris, Hôpital Lariboisière, Fédération de Rhumatologie, Paris, France
| | - M Cohen-Solal
- Inserm 1132, Hôpital Lariboisière, Paris, France; Université Paris Diderot, UFR médicale, Assistance Publique-Hôpitaux de Paris, Hôpital Lariboisière, Fédération de Rhumatologie, Paris, France
| | - P Richette
- Inserm 1132, Hôpital Lariboisière, Paris, France; Université Paris Diderot, UFR médicale, Assistance Publique-Hôpitaux de Paris, Hôpital Lariboisière, Fédération de Rhumatologie, Paris, France
| | - J Branco
- Department of Rheumatology, Hospital Egas Moniz, Centro Hospitalar Lisboa Ocidental EPE, Lisbon, Portugal; CEDOC - Chronic Diseases Research Center, NOVA Medical School, University Nova de Lisboa, Lisbon, Portugal
| | - M L Cancela
- Department of Biomedical Sciences and Medicine (DCBM), University of Algarve, Faro, Portugal; Centre of Marine Sciences (CCMAR), University of Algarve, Faro, Portugal
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23
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Righy C, Bozza MT, Oliveira MF, Bozza FA. Molecular, Cellular and Clinical Aspects of Intracerebral Hemorrhage: Are the Enemies Within? Curr Neuropharmacol 2016; 14:392-402. [PMID: 26714583 PMCID: PMC4876594 DOI: 10.2174/1570159x14666151230110058] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 11/28/2015] [Accepted: 12/29/2015] [Indexed: 12/13/2022] Open
Abstract
Hemorrhagic stroke is a disease with high incidence and mortality rates. In addition to the mass lesions that result from hemorrhagic stroke, substances such as the blood-derived products (BDP) (hemoglobin (Hb), heme and iron) induce a potent inflammatory response and exert direct toxic effects on neurons, astrocytes, and microglia. In the present review, we discuss the mechanisms of brain injury secondary to hemorrhagic stroke, focusing on the involvement of BDP as major players of cellular redox imbalance, inflammation, and glutamate excitotoxicity. Potential natural mechanisms of protection against free Hb and heme such as haptoglobin and hemopexin, respectively, are highlighted. We finally discuss the experimental and clinical trials targeting free iron and heme scavenging as well as inflammation, as potential new therapies to minimize the devastating effects of hemorrhagic stroke on brain structure and function.
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Affiliation(s)
- Cássia Righy
- Avenida Brasil 4.365, Manguinhos, Rio de Janeiro-RJ, CEP 21.040-900, Pavilhão Gaspar Viana.
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24
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Leitner DF, Todorich B, Zhang X, Connor JR. Semaphorin4A Is Cytotoxic to Oligodendrocytes and Is Elevated in Microglia and Multiple Sclerosis. ASN Neuro 2015; 7:7/3/1759091415587502. [PMID: 26024919 PMCID: PMC4449839 DOI: 10.1177/1759091415587502] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
We have previously established that T cell immunoglobulin and mucin domain containing 2 (Tim2) is an H-ferritin receptor on oligodendrocytes (OLs). Tim2 also binds Semaphorin4A (Sema4A). Sema4A is expressed by lymphocytes, and its role in immune activation is known; however, its relationship to diseases that are known to have myelin damage has not been studied. In this study, we demonstrate that Sema4A is cytotoxic to OLs in culture: an effect accompanied by process collapse, membrane blebbing, and phosphatidylserine inversion. We further demonstrate that Sema4A preferentially binds to primary OLs but not astrocytes: an observation consistent with the lack of expression of Tim2 on astrocytes. We found that Sema4A protein levels are increased within multiple sclerosis plaques compared with normal-appearing white matter and that Sema4A induces lactate dehydrogenase release in a human OL cell line. The chief cellular source of Sema4A within the multiple sclerosis plaques appears to be infiltrating lymphocytes and microglia. Macrophages are known to express Sema4A, so we interrogated microglia as a potential source of Sema4A in the brain. We found that rat primary microglia express Sema4A which increased after lipopolysaccharide activation. Because activated microglia accumulate iron, we determined whether iron status influenced Sema4A and found that iron chelation decreased Sema4A and iron loading increased Sema4A in activated microglia. Overall, our data implicate Sema4A in the destruction of OLs and reveal that its expression is sensitive to iron levels.
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Affiliation(s)
- Dominique F Leitner
- Department of Neurosurgery, Penn State University College of Medicine, Hershey, PA, USA
| | - Bozho Todorich
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA
| | - Xuesheng Zhang
- Department of Pediatrics, Penn State University College of Medicine, Hershey, PA, USA
| | - James R Connor
- Department of Neurosurgery, Penn State University College of Medicine, Hershey, PA, USA
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25
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Neubert J, Wagner S, Kiwit J, Bräuer AU, Glumm J. New findings about iron oxide nanoparticles and their different effects on murine primary brain cells. Int J Nanomedicine 2015; 10:2033-49. [PMID: 25792834 PMCID: PMC4364595 DOI: 10.2147/ijn.s74404] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The physicochemical properties of superparamagnetic iron oxide nanoparticles (SPIOs) enable their application in the diagnostics and therapy of central nervous system diseases. However, since crucial information regarding side effects of particle–cell interactions within the central nervous system is still lacking, we investigated the influence of novel very small iron oxide particles or the clinically approved ferucarbotran or ferumoxytol on the vitality and morphology of brain cells. We exposed primary cell cultures of microglia and hippocampal neurons, as well as neuron–glia cocultures to varying concentrations of SPIOs for 6 and/or 24 hours, respectively. Here, we show that SPIO accumulation by microglia and subsequent morphological alterations strongly depend on the respective nanoparticle type. Microglial viability was severely compromised by high SPIO concentrations, except in the case of ferumoxytol. While ferumoxytol did not cause immediate microglial death, it induced severe morphological alterations and increased degeneration of primary neurons. Additionally, primary neurons clearly degenerated after very small iron oxide particle and ferucarbotran exposure. In neuron–glia cocultures, SPIOs rather stimulated the outgrowth of neuronal processes in a concentration- and particle-dependent manner. We conclude that the influence of SPIOs on brain cells not only depends on the particle type but also on the physiological system they are applied to.
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Affiliation(s)
- Jenni Neubert
- Institute of Cell Biology and Neurobiology, Center for Anatomy, Charité-Universitaetsmedizin Berlin, Berlin, Germany
| | - Susanne Wagner
- Institute for Radiology, Charité-Universitaetsmedizin Berlin, Berlin, Germany
| | - Jürgen Kiwit
- Clinic for Neurosurgery, HELIOS Klinikum Berlin-Buch, Berlin, Germany
| | - Anja U Bräuer
- Institute of Cell Biology and Neurobiology, Center for Anatomy, Charité-Universitaetsmedizin Berlin, Berlin, Germany
| | - Jana Glumm
- Institute of Cell Biology and Neurobiology, Center for Anatomy, Charité-Universitaetsmedizin Berlin, Berlin, Germany ; Clinic for Neurosurgery, HELIOS Klinikum Berlin-Buch, Berlin, Germany
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26
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Zhang XY, Cao JB, Zhang LM, Li YF, Mi WD. Deferoxamine attenuates lipopolysaccharide-induced neuroinflammation and memory impairment in mice. J Neuroinflammation 2015; 12:20. [PMID: 25644393 PMCID: PMC4323121 DOI: 10.1186/s12974-015-0238-3] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 01/06/2015] [Indexed: 12/11/2022] Open
Abstract
Background Neuroinflammation often results in enduring cognitive impairment and is a risk factor for postoperative cognitive dysfunction. There are currently no effective treatments for infection-induced cognitive impairment. Previous studies have shown that the iron chelator deferoxamine (DFO) can increase the resistance of neurons to injury and disease by stimulating adaptive cellular stress responses. However, the impact of DFO on the cognitive sequelae of neuroinflammation is unknown. Methods A mouse model of lipopolysaccharide (LPS)-induced cognitive impairment was established to evaluate the neuroprotective effects of DFO against LPS-induced memory deficits and neuroinflammation. Adult C57BL/6 mice were treated with 0.5 μg of DFO 3 days prior to intracerebroventricular microinjection of 2 μg of LPS. Cognitive function was assessed using a Morris water maze from post-injection days 1 to 3. Animal behavioral tests, as well as pathological and biochemical assays were performed to evaluate the LPS-induced hippocampal damage and the neuroprotective effect of DFO. Results Treatment of mice with LPS resulted in deficits in cognitive performance in the Morris water maze without changing locomotor activity, which were ameliorated by pretreatment with DFO. DFO prevented LPS-induced microglial activation and elevations of IL-1β and TNF-α levels in the hippocampus. Moreover, DFO attenuated elevated expression of caspase-3, modulated GSK3β activity, and prevented LPS-induced increases of MDA and SOD levels in the hippocampus. DFO also significantly blocked LPS-induced iron accumulation and altered expression of proteins related to iron metabolism in the hippocampus. Conclusions Our results suggest that DFO may possess a neuroprotective effect against LPS-induced neuroinflammation and cognitive deficits via mechanisms involving maintenance of less brain iron, prevention of neuroinflammation, and alleviation of oxidative stress and apoptosis.
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Affiliation(s)
- Xiao-Ying Zhang
- Anesthesia and Operation Center, Chinese PLA General Hospital, Beijing, 100853, China.
| | - Jiang-Bei Cao
- Anesthesia and Operation Center, Chinese PLA General Hospital, Beijing, 100853, China.
| | - Li-Ming Zhang
- Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, Beijing, 100850, China.
| | - Yun-Feng Li
- Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, Beijing, 100850, China.
| | - Wei-Dong Mi
- Anesthesia and Operation Center, Chinese PLA General Hospital, Beijing, 100853, China.
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27
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Lovejoy DB, Guillemin GJ. The potential for transition metal-mediated neurodegeneration in amyotrophic lateral sclerosis. Front Aging Neurosci 2014; 6:173. [PMID: 25100994 PMCID: PMC4107949 DOI: 10.3389/fnagi.2014.00173] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 07/01/2014] [Indexed: 12/12/2022] Open
Abstract
Modulations of the potentially toxic transition metals iron (Fe) and copper (Cu) are implicated in the neurodegenerative process in a variety of human disease states including amyotrophic lateral sclerosis (ALS). However, the precise role played by these metals is still very much unclear, despite considerable clinical and experimental data suggestive of a role for these elements in the neurodegenerative process. The discovery of mutations in the antioxidant enzyme Cu/Zn superoxide dismutase 1 (SOD-1) in ALS patients established the first known cause of ALS. Recent data suggest that various mutations in SOD-1 affect metal-binding of Cu and Zn, in turn promoting toxic protein aggregation. Copper homeostasis is also disturbed in ALS, and may be relevant to ALS pathogenesis. Another set of interesting observations in ALS patients involves the key nutrient Fe. In ALS patients, Fe loading can be inferred by studies showing increased expression of serum ferritin, an Fe-storage protein, with high serum ferritin levels correlating to poor prognosis. Magnetic resonance imaging of ALS patients shows a characteristic T2 shortening that is attributed to the presence of Fe in the motor cortex. In mutant SOD-1 mouse models, increased Fe is also detected in the spinal cord and treatment with Fe-chelating drugs lowers spinal cord Fe, preserves motor neurons, and extends lifespan. Inflammation may play a key causative role in Fe accumulation, but this is not yet conclusive. Excess transition metals may enhance induction of endoplasmic reticulum (ER) stress, a system that is already under strain in ALS. Taken together, the evidence suggests a role for transition metals in ALS progression and the potential use of metal-chelating drugs as a component of future ALS therapy.
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Affiliation(s)
- David B Lovejoy
- Australian School of Advanced Medicine, Macquarie University , Sydney, NSW , Australia
| | - Gilles J Guillemin
- Australian School of Advanced Medicine, Macquarie University , Sydney, NSW , Australia
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28
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Abstract
Histochemical and MRI studies have demonstrated that MS (multiple sclerosis) patients have abnormal deposition of iron in both gray and white matter structures. Data is emerging indicating that this iron could partake in pathogenesis by various mechanisms, e.g., promoting the production of reactive oxygen species and enhancing the production of proinflammatory cytokines. Iron chelation therapy could be a viable strategy to block iron-related pathological events or it can confer cellular protection by stabilizing hypoxia inducible factor 1α, a transcription factor that normally responds to hypoxic conditions. Iron chelation has been shown to protect against disease progression and/or limit iron accumulation in some neurological disorders or their experimental models. Data from studies that administered a chelator to animals with experimental autoimmune encephalomyelitis, a model of MS, support the rationale for examining this treatment approach in MS. Preliminary clinical studies have been performed in MS patients using deferoxamine. Although some side effects were observed, the large majority of patients were able to tolerate the arduous administration regimen, i.e., 6-8 h of subcutaneous infusion, and all side effects resolved upon discontinuation of treatment. Importantly, these preliminary studies did not identify a disqualifying event for this experimental approach. More recently developed chelators, deferasirox and deferiprone, are more desirable for possible use in MS given their oral administration, and importantly, deferiprone can cross the blood-brain barrier. However, experiences from other conditions indicate that the potential for adverse events during chelation therapy necessitates close patient monitoring and a carefully considered administration regimen.
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29
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Luther EM, Petters C, Bulcke F, Kaltz A, Thiel K, Bickmeyer U, Dringen R. Endocytotic uptake of iron oxide nanoparticles by cultured brain microglial cells. Acta Biomater 2013; 9:8454-65. [PMID: 23727247 DOI: 10.1016/j.actbio.2013.05.022] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2012] [Revised: 05/17/2013] [Accepted: 05/21/2013] [Indexed: 11/29/2022]
Abstract
Microglia are the phagocytotic cells of the brain that respond rapidly to alterations in brain homeostasis. Since iron oxide nanoparticles (IONPs) are used for diagnostic and therapeutic applications in the brain, the consequences of an exposure of microglial cells to IONPs are of particular interest. To address this topic we have synthesized and characterized fluorescent BODIPY®-labelled IONPs (BP-IONPs). The average hydrodynamic diameter and the ζ-potential of BP-IONPs in water were ∼65 nm and -49 mV, respectively. Both values increased after dispersion of the particles in serum containing incubation medium to ∼130 nm and -8 mV. Exposure of cultured rat microglial cells with BP-IONPs caused a time-, concentration- and temperature-dependent uptake of the particles, as demonstrated by strong increases in cellular iron contents and cellular fluorescence. Incubation for 3h with 150 and 450 μM iron as BP-IONPs increased the cellular iron content from a low basal level of ∼50 nmol iron mg(-1) to 219±52 and 481±28 nmol iron (mg protein)(-1), respectively. These conditions did not affect cell viability, but exposure to higher concentrations of BP-IONPs or for longer incubation periods severely compromised cell viability. The BP-IONP fluorescence in viable microglial cells was co-localized with lysosomes. In addition, BP-IONP accumulation was lowered by 60% in the presence of the endocytosis inhibitors 5-(N-ethyl-N-isopropyl)amiloride, tyrphostin23 and chlorpromazin. These results suggest that the rapid accumulation of BP-IONPs by microglial cells is predominantly mediated by macropinocytosis and clathrin-mediated endocytosis, which direct the accumulated particles into the lysosomal compartment.
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Affiliation(s)
- Eva M Luther
- Center for Biomolecular Interactions Bremen, University of Bremen, P.O. Box 330440, D-28334 Bremen, Germany
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30
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Bagnato F, Hametner S, Yao B, van Gelderen P, Merkle H, Cantor FK, Lassmann H, Duyn JH. Tracking iron in multiple sclerosis: a combined imaging and histopathological study at 7 Tesla. Brain 2012; 134:3602-15. [PMID: 22171355 DOI: 10.1093/brain/awr278] [Citation(s) in RCA: 256] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Previous authors have shown that the transverse relaxivity R(2)* and frequency shifts that characterize gradient echo signal decay in magnetic resonance imaging are closely associated with the distribution of iron and myelin in the brain's white matter. In multiple sclerosis, iron accumulation in brain tissue may reflect a multiplicity of pathological processes. Hence, iron may have the unique potential to serve as an in vivo magnetic resonance imaging tracer of disease pathology. To investigate the ability of iron in tracking multiple sclerosis-induced pathology by magnetic resonance imaging, we performed qualitative histopathological analysis of white matter lesions and normal-appearing white matter regions with variable appearance on gradient echo magnetic resonance imaging at 7 Tesla. The samples used for this study derive from two patients with multiple sclerosis and one non-multiple sclerosis donor. Magnetic resonance images were acquired using a whole body 7 Tesla magnetic resonance imaging scanner equipped with a 24-channel receive-only array designed for tissue imaging. A 3D multi-gradient echo sequence was obtained and quantitative R(2)* and phase maps were reconstructed. Immunohistochemical stainings for myelin and oligodendrocytes, microglia and macrophages, ferritin and ferritin light polypeptide were performed on 3- to 5-µm thick paraffin sections. Iron was detected with Perl's staining and 3,3'-diaminobenzidine-tetrahydrochloride enhanced Turnbull blue staining. In multiple sclerosis tissue, iron presence invariably matched with an increase in R(2)*. Conversely, R(2)* increase was not always associated with the presence of iron on histochemical staining. We interpret this finding as the effect of embedding, sectioning and staining procedures. These processes likely affected the histopathological analysis results but not the magnetic resonance imaging that was obtained before tissue manipulations. Several cellular sources of iron were identified. These sources included oligodendrocytes in normal-appearing white matter and activated macrophages/microglia at the edges of white matter lesions. Additionally, in white matter lesions, iron precipitation in aggregates typical of microbleeds was shown by the Perl's staining. Our combined imaging and pathological study shows that multi-gradient echo magnetic resonance imaging is a sensitive technique for the identification of iron in the brain tissue of patients with multiple sclerosis. However, magnetic resonance imaging-identified iron does not necessarily reflect pathology and may also be seen in apparently normal tissue. Iron identification by multi-gradient echo magnetic resonance imaging in diseased tissues can shed light on the pathological processes when coupled with topographical information and patient disease history.
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Affiliation(s)
- Francesca Bagnato
- National Institutes of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Bethesda, MD, USA.
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31
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Williams R, Buchheit CL, Berman NEJ, LeVine SM. Pathogenic implications of iron accumulation in multiple sclerosis. J Neurochem 2011; 120:7-25. [PMID: 22004421 DOI: 10.1111/j.1471-4159.2011.07536.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Iron, an essential element used for a multitude of biochemical reactions, abnormally accumulates in the CNS of patients with multiple sclerosis (MS). The mechanisms of abnormal iron deposition in MS are not fully understood, nor do we know whether these deposits have adverse consequences, that is, contribute to pathogenesis. With some exceptions, excess levels of iron are represented concomitantly in multiple deep gray matter structures often with bilateral representation, whereas in white matter, pathological iron deposits are usually located at sites of inflammation that are associated with veins. These distinct spatial patterns suggest disparate mechanisms of iron accumulation between these regions. Iron has been postulated to promote disease activity in MS by various means: (i) iron can amplify the activated state of microglia resulting in the increased production of proinflammatory mediators; (ii) excess intracellular iron deposits could promote mitochondria dysfunction; and (iii) improperly managed iron could catalyze the production of damaging reactive oxygen species (ROS). The pathological consequences of abnormal iron deposits may be dependent on the affected brain region and/or accumulation process. Here, we review putative mechanisms of enhanced iron uptake in MS and address the likely roles of iron in the pathogenesis of this disease.
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Affiliation(s)
- Rachel Williams
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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