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Ashraf AA, Aljuhani M, Hubens CJ, Jeandriens J, Parkes HG, Geraki K, Mahmood A, Herlihy AH, So PW. Inflammation subsequent to mild iron excess differentially alters regional brain iron metabolism, oxidation and neuroinflammation status in mice. Front Aging Neurosci 2024; 16:1393351. [PMID: 38836051 PMCID: PMC11148467 DOI: 10.3389/fnagi.2024.1393351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 04/26/2024] [Indexed: 06/06/2024] Open
Abstract
Iron dyshomeostasis and neuroinflammation, characteristic features of the aged brain, and exacerbated in neurodegenerative disease, may induce oxidative stress-mediated neurodegeneration. In this study, the effects of potential priming with mild systemic iron injections on subsequent lipopolysaccharide (LPS)-induced inflammation in adult C57Bl/6J mice were examined. After cognitive testing, regional brain tissues were dissected for iron (metal) measurements by total reflection X-ray fluorescence and synchrotron radiation X-Ray fluorescence-based elemental mapping; and iron regulatory, ferroptosis-related, and glia-specific protein analysis, and lipid peroxidation by western blotting. Microglial morphology and astrogliosis were assessed by immunohistochemistry. Iron only treatment enhanced cognitive performance on the novel object location task compared with iron priming and subsequent LPS-induced inflammation. LPS-induced inflammation, with or without iron treatment, attenuated hippocampal heme oxygenase-1 and augmented 4-hydroxynonenal levels. Conversely, in the cortex, elevated ferritin light chain and xCT (light chain of System Xc-) were observed in response to LPS-induced inflammation, without and with iron-priming. Increased microglial branch/process lengths and astrocyte immunoreactivity were also increased by combined iron and LPS in both the hippocampus and cortex. Here, we demonstrate iron priming and subsequent LPS-induced inflammation led to iron dyshomeostasis, compromised antioxidant function, increased lipid peroxidation and altered neuroinflammatory state in a brain region-dependent manner.
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Affiliation(s)
- Azhaar Ahmad Ashraf
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Manal Aljuhani
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Chantal J Hubens
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Jérôme Jeandriens
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
- Department of Human Biology and Toxicology, Faculty of Medicine, University of Mons, Mons, Belgium
| | - Harold G Parkes
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Kalotina Geraki
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, United Kingdom
| | - Ayesha Mahmood
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | | | - Po-Wah So
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
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Hou W, Ji Z. GPT-4V exhibits human-like performance in biomedical image classification. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.31.573796. [PMID: 38260646 PMCID: PMC10802384 DOI: 10.1101/2023.12.31.573796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
We demonstrate that GPT-4V(ision), a large multimodal model, exhibits strong one-shot learning ability, generalizability, and natural language interpretability in various biomedical image classification tasks, including classifying cell types, tissues, cell states, and disease status. Such features resemble human-like performance and distinguish GPT-4V from conventional image classification methods, which typically require large cohorts of training data and lack interpretability.
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Affiliation(s)
- Wenpin Hou
- Department of Biostatistics, The Mailman School of Public Health, Columbia University, New York City, NY, USA
| | - Zhicheng Ji
- Department of Biostatistics and Bioinformatics, Duke University School of Medicine, Durham, NC, USA
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3
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Mertens C, Marques O, Horvat NK, Simonetti M, Muckenthaler MU, Jung M. The Macrophage Iron Signature in Health and Disease. Int J Mol Sci 2021; 22:ijms22168457. [PMID: 34445160 PMCID: PMC8395084 DOI: 10.3390/ijms22168457] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 07/30/2021] [Accepted: 08/02/2021] [Indexed: 12/13/2022] Open
Abstract
Throughout life, macrophages are located in every tissue of the body, where their main roles are to phagocytose cellular debris and recycle aging red blood cells. In the tissue niche, they promote homeostasis through trophic, regulatory, and repair functions by responding to internal and external stimuli. This in turn polarizes macrophages into a broad spectrum of functional activation states, also reflected in their iron-regulated gene profile. The fast adaptation to the environment in which they are located helps to maintain tissue homeostasis under physiological conditions.
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Affiliation(s)
- Christina Mertens
- Department of Pediatric Hematology, Oncology and Immunology, University of Heidelberg, INF 350, 69120 Heidelberg, Germany; (O.M.); (N.K.H.); (M.U.M.)
- Correspondence: (C.M.); (M.J.); Tel.: +(49)-622-156-4582 (C.M.); +(49)-696-301-6931 (M.J.)
| | - Oriana Marques
- Department of Pediatric Hematology, Oncology and Immunology, University of Heidelberg, INF 350, 69120 Heidelberg, Germany; (O.M.); (N.K.H.); (M.U.M.)
- Molecular Medicine Partnership Unit, 69120 Heidelberg, Germany
| | - Natalie K. Horvat
- Department of Pediatric Hematology, Oncology and Immunology, University of Heidelberg, INF 350, 69120 Heidelberg, Germany; (O.M.); (N.K.H.); (M.U.M.)
- Molecular Medicine Partnership Unit, 69120 Heidelberg, Germany
- European Molecular Biology Laboratory (EMBL), Collaboration for Joint PhD Degree between EMBL and the Faculty of Biosciences, University of Heidelberg, 69117 Heidelberg, Germany
| | - Manuela Simonetti
- Institute of Pharmacology, Medical Faculty Heidelberg, Heidelberg University, INF 366, 69120 Heidelberg, Germany;
| | - Martina U. Muckenthaler
- Department of Pediatric Hematology, Oncology and Immunology, University of Heidelberg, INF 350, 69120 Heidelberg, Germany; (O.M.); (N.K.H.); (M.U.M.)
- Molecular Medicine Partnership Unit, 69120 Heidelberg, Germany
| | - Michaela Jung
- Institute of Biochemistry I, Faculty of Medicine, Goethe-University Frankfurt, 60590 Frankfurt, Germany
- Correspondence: (C.M.); (M.J.); Tel.: +(49)-622-156-4582 (C.M.); +(49)-696-301-6931 (M.J.)
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N-Acetylcysteine Nanocarriers Protect against Oxidative Stress in a Cellular Model of Parkinson's Disease. Antioxidants (Basel) 2020; 9:antiox9070600. [PMID: 32660079 PMCID: PMC7402157 DOI: 10.3390/antiox9070600] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 07/03/2020] [Accepted: 07/07/2020] [Indexed: 12/20/2022] Open
Abstract
Oxidative stress is a key mediator in the development and progression of Parkinson's disease (PD). The antioxidant n-acetylcysteine (NAC) has generated interest as a disease-modifying therapy for PD but is limited due to poor bioavailability, a short half-life, and limited access to the brain. The aim of this study was to formulate and utilise mitochondria-targeted nanocarriers for delivery of NAC alone and in combination with the iron chelator deferoxamine (DFO), and assess their ability to protect against oxidative stress in a cellular rotenone PD model. Pluronic F68 (P68) and dequalinium (DQA) nanocarriers were prepared by a modified thin-film hydration method. An MTT assay assessed cell viability and iron status was measured using a ferrozine assay and ferritin immunoassay. For oxidative stress, a modified cellular antioxidant activity assay and the thiobarbituric acid-reactive substances assay and mitochondrial hydroxyl assay were utilised. Overall, this study demonstrates, for the first time, successful formulation of NAC and NAC + DFO into P68 + DQA nanocarriers for neuronal delivery. The results indicate that NAC and NAC + DFO nanocarriers have the potential characteristics to access the brain and that 1000 μM P68 + DQA NAC exhibited the strongest ability to protect against reduced cell viability (p = 0.0001), increased iron (p = 0.0033) and oxidative stress (p ≤ 0.0003). These NAC nanocarriers therefore demonstrate significant potential to be transitioned for further preclinical testing for PD.
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Li C, Bian Y, Feng Y, Tang F, Wang L, Hoi MPM, Ma D, Zhao C, Lee SMY. Neuroprotective Effects of BHDPC, a Novel Neuroprotectant, on Experimental Stroke by Modulating Microglia Polarization. ACS Chem Neurosci 2019; 10:2434-2449. [PMID: 30839193 DOI: 10.1021/acschemneuro.8b00713] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
This study mainly investigated the therapeutic effects of BHDPC on ischemic stroke and its underlying mechanisms. In vivo, the transient middle cerebral artery occlusion (MCAO) was used to induce ischemic model. In vitro, oxygen and glucose deprivation/reperfusion (OGD/R)-induced ischemic stroke in BV-2 microglia and primary neurons, and bEnd.3 mouse cerebral microvascular endothelial cells (ECs) were also used. First, we found that BHDPC exerts considerable neuroprotection against MCAO-induced ischemic injury to mice via alleviating neurological deficits and brain infarcts, inhibiting neuronal cell loss and apoptosis, and attenuating blood-brain barrier disruption and tight junction protein changes. Next, we observed that BHDPC significantly reduced microglial M1 activation but enhanced M2 polarization in MCAO-induced ischemic brain. Further experiments in vitro indicated that BHDPC suppressed microglial activation but promoted M2 microglial polarization in OGD/R-induced BV-2 microglia. In addition, conditioned medium (CM) experiments showed that CM from BHDPC-treated BV-2 microglia provided protections against OGD/R-induced ischemic damage in primary neurons and bEnd.3 ECs. Moreover, we found that BHDPC actions on microglial inflammation were associated with the inactivation of NF-κB signaling. Interestingly, we also found that BHDPC enhanced phosphorylation of protein kinase A (PKA) and cAMP-response element-binding protein (CREB). The pharmacological inhibition or gene knockdown of PKA/CREB signaling diminished BHDPC-promoted microglial M2 polarization. In summary, BHDPC conferred neuroprotection against ischemic injury in experimental stroke models. Modulating microglial activation and polarization contributes to BHDPC-mediated neuroprotective actions, which in part were mediated by nuclear factor kappa B and PKA/CREB signaling pathway.
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Affiliation(s)
- Chuwen Li
- Key Laboratory of Molecular Target & Clinical Pharmacology, School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou 510182, China
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau 999078, China
| | - Yaqi Bian
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau 999078, China
| | - Yu Feng
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau 999078, China
| | - Fan Tang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau 999078, China
| | - Liang Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau 999078, China
| | - Maggie Pui Man Hoi
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau 999078, China
| | - Dan Ma
- Department of Clinical Neurosciences, Wellcome Trust-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AH, U.K
| | - Chao Zhao
- Department of Clinical Neurosciences, Wellcome Trust-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AH, U.K
| | - Simon Ming Yuen Lee
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau 999078, China
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Almutairi MMA, Xu G, Shi H. Iron Pathophysiology in Stroke. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1173:105-123. [PMID: 31456207 DOI: 10.1007/978-981-13-9589-5_6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Ischemic and hemorrhagic stroke are the common types of stroke that lead to brain injury neurological deficits and mortality. All forms of stroke remain a serious health issue, and there is little successful development of drugs for treating stroke. Incomplete understanding of stroke pathophysiology is considered the main barrier that limits this research progress. Besides mitochondria and free radical-producing enzymes, labile iron is an important contributor to oxidative stress. Although iron regulation and metabolism in cerebral stroke are not fully understood, much progress has been achieved in recent years. For example, hepcidin has recently been recognized as the principal regulator of systemic iron homeostasis and a bridge between inflammation and iron regulation. This review discusses recent research progress in iron pathophysiology following cerebral stroke, focusing molecular regulation of iron metabolism and potential treatment targets.
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Affiliation(s)
- Mohammed M A Almutairi
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, 66045, USA.,Department of Pharmacology and Toxicology, School of Pharmacy, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Grace Xu
- Department of Anesthesiology, School of Medicine, University of Kansas, Kansas City, KS, 66160, USA
| | - Honglian Shi
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, 66045, USA.
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Daglas M, Adlard PA. The Involvement of Iron in Traumatic Brain Injury and Neurodegenerative Disease. Front Neurosci 2018; 12:981. [PMID: 30618597 PMCID: PMC6306469 DOI: 10.3389/fnins.2018.00981] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 12/07/2018] [Indexed: 12/18/2022] Open
Abstract
Traumatic brain injury (TBI) consists of acute and long-term pathophysiological sequelae that ultimately lead to cognitive and motor function deficits, with age being a critical risk factor for poorer prognosis. TBI has been recently linked to the development of neurodegenerative diseases later in life including Alzheimer’s disease, Parkinson’s disease, chronic traumatic encephalopathy, and multiple sclerosis. The accumulation of iron in the brain has been documented in a number of neurodegenerative diseases, and also in normal aging, and can contribute to neurotoxicity through a variety of mechanisms including the production of free radicals leading to oxidative stress, excitotoxicity and by promoting inflammatory reactions. A growing body of evidence similarly supports a deleterious role of iron in the pathogenesis of TBI. Iron deposition in the injured brain can occur via hemorrhage/microhemorrhages (heme-bound iron) or independently as labile iron (non-heme bound), which is considered to be more damaging to the brain. This review focusses on the role of iron in potentiating neurodegeneration in TBI, with insight into the intersection with neurodegenerative conditions. An important implication of this work is the potential for therapeutic approaches that target iron to attenuate the neuropathology/phenotype related to TBI and to also reduce the associated risk of developing neurodegenerative disease.
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Affiliation(s)
- Maria Daglas
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Paul A Adlard
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
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8
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Model Senescent Microglia Induce Disease Related Changes in α-Synuclein Expression and Activity. Biomolecules 2018; 8:biom8030067. [PMID: 30071596 PMCID: PMC6164966 DOI: 10.3390/biom8030067] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 07/24/2018] [Accepted: 07/26/2018] [Indexed: 12/13/2022] Open
Abstract
Aging is the most prominent risk factor for most neurodegenerative diseases. However, incorporating aging-related changes into models of neurodegeneration rarely occurs. One of the significant changes that occurs in the brain as we age is the shift in phenotype of the resident microglia population to one less able to respond to deleterious changes in the brain. These microglia are termed dystrophic microglia. In order to better model neurodegenerative diseases, we have developed a method to convert microglia into a senescent phenotype in vitro. Mouse microglia grown in high iron concentrations showed many characteristics of dystrophic microglia including, increased iron storage, increased expression of proteins, such as ferritin and the potassium channel, Kv1.3, increased reactive oxygen species production and cytokine release. We have applied this new model to the study of α-synuclein, a protein that is closely associated with a number of neurodegenerative diseases. We have shown that conditioned medium from our model dystrophic microglia increases α-synuclein transcription and expression via tumor necrosis factor alpha (TNFα) and mediated through nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). The conditioned medium also decreases the formation of α-synuclein tetramers, associated ferrireductase activity, and increases aggregates of α-synuclein. The results suggest that we have developed an interesting new model of aged microglia and that factors, including TNFα released from dystrophic microglia could have a significant influence on the pathogenesis of α-synuclein related diseases.
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Li C, Chen T, Zhou H, Feng Y, Hoi MPM, Ma D, Zhao C, Zheng Y, Lee SMY. BHDPC Is a Novel Neuroprotectant That Provides Anti-neuroinflammatory and Neuroprotective Effects by Inactivating NF-κB and Activating PKA/CREB. Front Pharmacol 2018; 9:614. [PMID: 29988625 PMCID: PMC6027181 DOI: 10.3389/fphar.2018.00614] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 05/22/2018] [Indexed: 12/31/2022] Open
Abstract
Microglia-mediated neuroinflammatory responses are inevitable and important pathological processes in several kinds of disorder of the central nervous system (CNS). Therefore, alleviating activated microglia-induced inflammatory process might be a valuable therapeutic approach to neuroinflammation-related diseases. In the present study, we investigated BHDPC, a novel neuroprotectant discovered in our previous study that had anti-inflammatory effects under neuroinflammatory conditions. First, we found that BHDPC could inhibit neuroinflammatory responses and promote microglial M2 phenotype polarization in both lipopolysaccharide (LPS)-activated BV-2 microglia l cells. Furthermore, BHDPC provided protective actions against neuroinflammation-induced neurotoxicity in HT22 mouse hippocampal cells co-cultured with activated BV-2 microglia. Further experiments demonstrated that BHDPC could suppress LPS-induced activation of transcription factor nuclear factor kappa B (NF-κB) via interfering with the degradation of the inhibitor of kappa B (IκB) and phosphorylation of IκB, the IκB kinase (IKK). Moreover, we also found that BHDPC could induce phosphorylation of cAMP-dependent protein kinase A (PKA) and cAMP-response element-binding protein (CREB) in BV-2 microglial cells. Also, using the PKA-specific inhibitor, we found that BHDPC-induced CREB phosphorylation was dependent on PKA, which also contributed to BHDPC-mediated anti-inflammation and neuroprotection.
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Affiliation(s)
- Chuwen Li
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Tongkai Chen
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China.,Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Hefeng Zhou
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Yu Feng
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Maggie P M Hoi
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Dan Ma
- Department of Clinical Neurosciences, Wellcome Trust-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Chao Zhao
- Department of Clinical Neurosciences, Wellcome Trust-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Ying Zheng
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Simon M Y Lee
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
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10
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Li C, Zhang C, Zhou H, Feng Y, Tang F, Hoi MPM, He C, Ma D, Zhao C, Lee SMY. Inhibitory Effects of Betulinic Acid on LPS-Induced Neuroinflammation Involve M2 Microglial Polarization via CaMKKβ-Dependent AMPK Activation. Front Mol Neurosci 2018; 11:98. [PMID: 29666569 PMCID: PMC5891622 DOI: 10.3389/fnmol.2018.00098] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 03/13/2018] [Indexed: 11/13/2022] Open
Abstract
In response to the microenvironment, microglia may polarize into either an M1 pro-inflammatory phenotype, exacerbating neurotoxicity, or an M2 anti-inflammatory phenotype, conferring neuroprotection. Betulinic acid (BA) is a naturally pentacyclic triterpenoid with considerable anti-inflammatory properties. Here, we aim to investigate the potential effects of BA on microglial phenotype polarization and to reveal the underlying mechanisms of action. First, we confirmed that BA promoted M2 polarization and inhibited M1 polarization in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. Then, we demonstrated that the effect of BA on microglial polarization was dependent on AMP-activated protein kinase (AMPK) activation, as evidenced by the fact that both AMPK inhibitor compound C and AMPK siRNA abolished the M2 polarization promoted by BA. Moreover, we found that calmodulin-dependent protein kinase kinase β (CaMKKβ), but not liver kinase B1, was the upstream kinase required for BA-mediated AMPK activation and microglial M2 polarization, via the use of both the CaMKKβ inhibitor STO-609 and CaMKKβ siRNA. Finally, BA enhanced AMPK phosphorylation and promoted M2 microglial polarization in the cerebral cortex of LPS-injected mice brains, which was attenuated by pre-administration of the AMPK inhibitor. This study demonstrated that BA promoted M2 polarization of microglia, thus conferring anti-neuroinflammatory effects via CaMKKβ-dependent AMPK activation.
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Affiliation(s)
- Chuwen Li
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Chao Zhang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China.,School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Hefeng Zhou
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Yu Feng
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Fan Tang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Maggie P M Hoi
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Chengwei He
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Dan Ma
- Department of Clinical Neurosciences, Wellcome Trust-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Chao Zhao
- Department of Clinical Neurosciences, Wellcome Trust-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Simon M Y Lee
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
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11
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Abstract
Brain iron is tightly regulated by a multitude of proteins to ensure homeostasis. Iron dyshomeostasis has become a molecular signature associated with aging which is accompanied by progressive decline in cognitive processes. A common theme in neurodegenerative diseases where age is the major risk factor, iron dyshomeostasis coincides with neuroinflammation, abnormal protein aggregation, neurodegeneration, and neurobehavioral deficits. There is a great need to determine the mechanisms governing perturbations in iron metabolism, in particular to distinguish between physiological and pathological aging to generate fruitful therapeutic targets for neurodegenerative diseases. The aim of the present review is to focus on the age-related alterations in brain iron metabolism from a cellular and molecular biology perspective, alongside genetics, and neuroimaging aspects in man and rodent models, with respect to normal aging and neurodegeneration. In particular, the relationship between iron dyshomeostasis and neuroinflammation will be evaluated, as well as the effects of systemic iron overload on the brain. Based on the evidence discussed here, we suggest a synergistic use of iron-chelators and anti-inflammatories as putative anti-brain aging therapies to counteract pathological aging in neurodegenerative diseases.
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Affiliation(s)
- Azhaar Ashraf
- Institute of Psychiatry, Psychology and Neuroscience, Department of Neuroimaging, King's College London, London, United Kingdom
| | - Maryam Clark
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Po-Wah So
- Institute of Psychiatry, Psychology and Neuroscience, Department of Neuroimaging, King's College London, London, United Kingdom
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12
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Chen R, Yang Y, Xu J, Pan Y, Zhang W, Xing Y, Ni H, Sun Y, Hou Y, Li N. Tamarix hohenackeri Bunge exerts anti-inflammatory effects on lipopolysaccharide-activated microglia in vitro. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2018; 40:10-19. [PMID: 29496162 DOI: 10.1016/j.phymed.2017.12.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 12/11/2017] [Accepted: 12/28/2017] [Indexed: 06/08/2023]
Abstract
BACKGROUND Tamarix species are well known as the main host plants of Herba Cistanches, a valuable Traditional Chinese Medicine. They are also traditional medicinal plants themselves and are used to treat spleen problems, leucoderma and ocular conditions. PURPOSE The aim of the present study was to investigate the anti-inflammatory effect of Tamarix hohenackeri Bunge. METHODS In the present study, BV-2 microglial cells were used and stimulated with lipopolysaccharide (LPS). Cell viability was tested using the MTT assay. The release of nitric oxide (NO) was determined using the Griess assay. The mRNA level of inducible nitric oxide synthase (iNOS), tumor necrosis factor α (TNF-α), interleukin (IL)-1β and IL-6 were investigated by quantitative real-time PCR (qRT-PCR). The protein levels of phosphorylated of IκBα, ERK and MEK, as well as the cytoplasmic and nuclear NF-κB p65 were tested by Western blot analysis. The translocation of the NF-κB p65 subunit from the cytosol to the nucleus was investigated by immunofluorescence staining. RESULTS Ethyl acetate (EtOAc) extract of Tamarix hohenackeri Bunge significantly inhibited the release of NO. Phytochemical research was performed to produce 13 main constituents. Among them, compounds 6, 7, 10 and 13 were identified to be the effective components with anti-inflammatory activity. These compounds significantly inhibited the production of NO by LPS-activated BV-2 microglial cells. qRT-PCR showed that compounds 6 and 7 significantly suppressed the LPS-induced transcription of genes encoding pro-inflammatory mediators, including iNOS, TNF-α, IL-1β and IL-6. Western blot analysis showed that compound 7 inhibited the LPS-induced phosphorylation of IκBα and antagonized the LPS-induced reduction of cytoplasmic NF-κB p65 and the increase of nuclear NF-κB p65. Immunofluorescence staining showed that nuclear translocation of NF-κB p65 was suppressed by compound 7. Western blot analysis showed that compound 7 inhibited the LPS-induced phosphorylation of ERK and MEK. CONCLUSION The present study revealed, for the first time, the effective anti-inflammatory agents from T. Hohenackeri. Compound 7 exerted potent anti-inflammatory effects and its underlying mechanism may be associated with its capacity to inhibit NF-κB signaling pathway and the MEK/ERK activation in activated microglia. The compound may be potential candidate therapeutic agent for neurodegenerative diseases.
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Affiliation(s)
- Ru Chen
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Yanqiu Yang
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Jikai Xu
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Yingni Pan
- School of Traditional Chinese Materia Medica, Key Laboratory of Structure-Based Drug Design and Discovery, Shenyang Pharmaceutical University, Ministry of Education, Shenyang, China
| | - Wenqiang Zhang
- College of Life and Health Sciences, Northeastern University, Shenyang, China
| | - Yachao Xing
- School of Traditional Chinese Materia Medica, Key Laboratory of Structure-Based Drug Design and Discovery, Shenyang Pharmaceutical University, Ministry of Education, Shenyang, China
| | - Hui Ni
- XinJiang Institute of Chinese Materia Medica and Ethnodrug, Urumqi, China
| | - Yu Sun
- XinJiang Institute of Chinese Materia Medica and Ethnodrug, Urumqi, China
| | - Yue Hou
- College of Life and Health Sciences, Northeastern University, Shenyang, China.
| | - Ning Li
- School of Traditional Chinese Materia Medica, Key Laboratory of Structure-Based Drug Design and Discovery, Shenyang Pharmaceutical University, Ministry of Education, Shenyang, China.
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Okanin, effective constituent of the flower tea Coreopsis tinctoria, attenuates LPS-induced microglial activation through inhibition of the TLR4/NF-κB signaling pathways. Sci Rep 2017; 7:45705. [PMID: 28367982 PMCID: PMC5377376 DOI: 10.1038/srep45705] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 03/03/2017] [Indexed: 11/08/2022] Open
Abstract
The EtOAc extract of Coreopsis tinctoria Nutt. significantly inhibited LPS-induced nitric oxide (NO) production, as judged by the Griess reaction, and attenuated the LPS-induced elevation in iNOS, COX-2, IL-1β, IL-6 and TNF-α mRNA levels, as determined by quantitative real-time PCR, when incubated with BV-2 microglial cells. Immunohistochemical results showed that the EtOAc extract significantly decreased the number of Iba-1-positive cells in the hippocampal region of LPS-treated mouse brains. The major effective constituent of the EtOAc extract, okanin, was further investigated. Okanin significantly suppressed LPS-induced iNOS expression and also inhibited IL-6 and TNF-α production and mRNA expression in LPS-stimulated BV-2 cells. Western blot analysis indicated that okanin suppressed LPS-induced activation of the NF-κB signaling pathway by inhibiting the phosphorylation of IκBα and decreasing the level of nuclear NF-κB p65 after LPS treatment. Immunofluorescence staining results showed that okanin inhibited the translocation of the NF-κB p65 subunit from the cytosol to the nucleus. Moreover, okanin significantly inhibited LPS-induced TLR4 expression in BV-2 cells. In summary, okanin attenuates LPS-induced activation of microglia. This effect may be associated with its capacity to inhibit the TLR4/NF-κB signaling pathways. These results suggest that okanin may have potential as a nutritional preventive strategy for neurodegenerative disorders.
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Li N, Wang Y, Li X, Zhang H, Zhou D, Wang W, Li W, Zhang X, Li X, Hou Y, Meng D. Bioactive phenols as potential neuroinflammation inhibitors from the leaves of Xanthoceras sorbifolia Bunge. Bioorg Med Chem Lett 2016; 26:5018-5023. [DOI: 10.1016/j.bmcl.2016.08.094] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 08/26/2016] [Accepted: 08/30/2016] [Indexed: 01/14/2023]
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Hou Y, Li N, Xie G, Wang J, Yuan Q, Jia C, Liu X, Li G, Tang Y, Wang B. Pterostilbene exerts anti-neuroinflammatory effect on lipopolysaccharide-activated microglia via inhibition of MAPK signalling pathways. J Funct Foods 2015. [DOI: 10.1016/j.jff.2015.10.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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16
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Li N, Meng D, Pan Y, Cui Q, Li G, Ni H, Sun Y, Qing D, Jia X, Pan Y, Hou Y. Anti-neuroinflammatory and NQO1 inducing activity of natural phytochemicals from Coreopsis tinctoria. J Funct Foods 2015. [DOI: 10.1016/j.jff.2015.06.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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Natural therapeutic agents for neurodegenerative diseases from a traditional herbal medicine Pongamia pinnata (L.) Pierre. Bioorg Med Chem Lett 2014; 25:53-8. [PMID: 25466192 DOI: 10.1016/j.bmcl.2014.11.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 10/02/2014] [Accepted: 11/05/2014] [Indexed: 01/28/2023]
Abstract
Neurodegenerative diseases are associated with neuroinflammation, manifested by over-production of nitric oxide (NO) by microglial cells. Now there still lack effective treatment and prevention for the neurodegenerative diseases. Concerning neuroinflammation mediated by microglia cell, bioactivity-guided phytochemical research of Pongamia pinnata (L.) Pierre was performed in this study. A new chlorinated flavonoid, 2′,6′-dichlore-3′, 5′-dimethoxy-[2′′,3′′:7,8]-furanoflavone (1) was identified together with 29 known compounds, including flavonoids (compounds 2-17), isoflavonoids (compounds 18-23), chalcones (compounds 24-25), flavonones (compounds 26-27), triterpenes (28-29) and alkaloid (30) from the effective dichloride methane extract of dry stem of P. pinnata (L.) Pierre. Their structures were elucidated by physicochemical and spectral methods. The anti-neuroinflammatory activities were assayed in BV-2 cells by assessing LPS-induced NO production. Then pongaglabol methyl ether (2), lonchocarpin (24) and glabrachromene II (25) were selected as potential therapeutic agents for neurodegenerative diseases because of their significant anti-neuroinflammatory activities. Furthermore, the characteristics of structure type existing in P. pinnata (L.) Pierre and brief SAR were summarized, respectively.
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Li N, Ma Z, Li M, Xing Y, Hou Y. Natural potential therapeutic agents of neurodegenerative diseases from the traditional herbal medicine Chinese dragon's blood. JOURNAL OF ETHNOPHARMACOLOGY 2014; 152:508-521. [PMID: 24509154 DOI: 10.1016/j.jep.2014.01.032] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 01/26/2014] [Accepted: 01/28/2014] [Indexed: 06/03/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Dragon's blood has been used as a famous traditional medicine since ancient times by many cultures. It is a deep red resin, obtained from more than 20 different species of four distinct genera. Red resin of Dracaena cochinchinensis S.C. Chen, known as Chinese dragon's blood or Yunnan dragon's blood, has been shown to promote blood circulation, alleviate inflammation, and to treat stomach ulcers, diarrhea, diabetes, and bleeding. This study investigated an effective approach to identify natural therapeutic agents for neurodegeneration from herbal medicine. The dichloride extract and isolated effective constituents of Chinese dragon's blood showed quinone oxidoreductase 1 (NQO1) inducing activity and anti-inflammatory effect significantly, which are therapy targets of various neurodegenerative diseases. MATERIALS AND METHODS Multiple chromatography and spectra analysis were utilized to afford effective constituents. Then Hepa 1c1c7 and BV-2 cells were employed to assay their NQO1 inducing and anti-inflammatory activities, respectively. RESULTS Bioactivities guided isolation afforded 21 effective constituents, including two new polymers cochinchinenene E (1), cochinchinenene F (2) and a new steroid dracaenol C (16). The main constituent 3 (weight percent 0.2%), 5 (weight percent 0.017%), 4 (weight percent 0.009%), 9 (weight percent 0.094%), 10 (weight percent 0.017%) and 8 (weight percent 0.006%) are responsible for the anti-inflammatory activities of Chinese dragon's blood. While, new compounds 1, 2 and known compounds 5, 11 showed good NQO1 inducing activities. The brief feature of the activities and structures was discussed accordingly. CONCLUSION Overviewing the bioactivities and phytochemical study result, 4'-hydroxy-2,4-dimethoxydihydrochalcone (3) and pterostilbene (5) as effective constituents of Chinese dragon's blood, were found to be potential candidate therapeutic agents for neurodegenerative diseases.
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Key Words
- 1,2,4,5-Tetrachloro-3,6-dimethoxybenzene (PubChem CID: 13678).
- 10-Hydroxy-11-methoxy dracaenone (PubChem CID: 3081034)
- 3,4-Dihydroxyallylbenzene (PubChem CID: 70775)
- 4'-Hydroxy-2,4,6-trimethoxydihydro chalcone (PubChem CID: 189670)
- 4'-Hydroxy-2,4-dimethoxydihydrochalcone (PubChem CID: 5319081)
- 6,4'-Dihydroxy-7-methoxyhomoisoflavane (PubChem CID: 25014549)
- 6-Methoxy-7-hydroxyflavone (PubChem CID: 14376438)
- 7,4'-Dihydroxy-homoisoflavane (PubChem CID: 11708657)
- 7-Hydroxy-4'-methoxyflavane (PubChem CID: 3483299)
- Anti-inflammatory effect
- Chinese Dragon׳s Blood
- Dracaena cochinchinensis S.C. Chen
- NQO1 inducing activity
- Polymers
- Pterostilbene (PubChem CID: 5281727)
- Therapeutic agents for neurodegenerative diseases
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Affiliation(s)
- Ning Li
- School of Traditional Chinese Materia Medica 49(#), Key Laboratory of Structure-Based Drug Design and Discovery, Shenyang Pharmaceutical University, Ministry of Education, Wenhua Road 103, Shenyang 110016, China.
| | - Zhongjun Ma
- Department of Ocean Science and Engineering, Zhejiang University, Hangzhou 310058, China
| | - Mujie Li
- School of Traditional Chinese Materia Medica 49(#), Key Laboratory of Structure-Based Drug Design and Discovery, Shenyang Pharmaceutical University, Ministry of Education, Wenhua Road 103, Shenyang 110016, China
| | - Yachao Xing
- School of Traditional Chinese Materia Medica 49(#), Key Laboratory of Structure-Based Drug Design and Discovery, Shenyang Pharmaceutical University, Ministry of Education, Wenhua Road 103, Shenyang 110016, China
| | - Yue Hou
- College of Life and Health Sciences, Northeastern University, Shenyang 110004, China
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Urrutia P, Aguirre P, Esparza A, Tapia V, Mena NP, Arredondo M, González-Billault C, Núñez MT. Inflammation alters the expression of DMT1, FPN1 and hepcidin, and it causes iron accumulation in central nervous system cells. J Neurochem 2013; 126:541-9. [PMID: 23506423 DOI: 10.1111/jnc.12244] [Citation(s) in RCA: 261] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 02/27/2013] [Accepted: 03/01/2013] [Indexed: 12/23/2022]
Abstract
Inflammation and iron accumulation are present in a variety of neurodegenerative diseases that include Alzheimer's disease and Parkinson's disease. The study of the putative association between inflammation and iron accumulation in central nervous system cells is relevant to understand the contribution of these processes to the progression of neuronal death. In this study, we analyzed the effects of the inflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) and of lipopolysaccharide on total cell iron content and on the expression and abundance of the iron transporters divalent metal transporter 1 (DMT1) and Ferroportin 1 (FPN1) in neurons, astrocytes and microglia obtained from rat brain. Considering previous reports indicating that inflammatory stimuli induce the systemic synthesis of the master iron regulator hepcidin, we identified brain cells that produce hepcidin in response to inflammatory stimuli, as well as hepcidin-target cells. We found that inflammatory stimuli increased the expression of DMT1 in neurons, astrocytes, and microglia. Inflammatory stimuli also induced the expression of hepcidin in astrocytes and microglia, but not in neurons. Incubation with hepcidin decreased the expression of FPN1 in the three cell types. The net result of these changes was increased iron accumulation in neurons and microglia but not in astrocytes. The data presented here establish for the first time a causal association between inflammation and iron accumulation in brain cells, probably promoted by changes in DMT1 and FPN1 expression and mediated in part by hepcidin. This connection may potentially contribute to the progression of neurodegenerative diseases by enhancing iron-induced oxidative damage.
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Affiliation(s)
- Pamela Urrutia
- Department of Biology, Faculty of Sciences, Universidad de Chile and Research Ring on Oxidative Stress in the Nervous System, Santiago, Chile
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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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Stachowski EK, Schwarcz R. Regulation of quinolinic acid neosynthesis in mouse, rat and human brain by iron and iron chelators in vitro. J Neural Transm (Vienna) 2011; 119:123-31. [PMID: 21833493 DOI: 10.1007/s00702-011-0694-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Accepted: 07/22/2011] [Indexed: 12/30/2022]
Abstract
Several lines of evidence indicate that excess iron may play an etiologically significant role in neurodegenerative disorders. This idea is supported, for example, by experimental studies in animals demonstrating significant neuroprotection by iron chelation. Here, we tested whether this effect might be related to a functional link between iron and the endogenous excitotoxin quinolinic acid (QUIN), a presumed pathogen in several neurological disorders. In particular, the present in vitro study was designed to examine the effects of Fe(2+), a known co-factor of oxygenases, on the activity of QUIN's immediate biosynthetic enzyme, 3-hydroxyanthranilic acid dioxygenase (3HAO), in the brain. In crude tissue homogenate, addition of Fe(2+) (2-40 μM) stimulated 3HAO activity 4- to 6-fold in all three species tested (mouse, rat and human). The slope of the iron curve was steepest in rat brain where an increase from 6 to 14 μM resulted in a more than fivefold higher enzyme activity. In all species, the Fe(2+)-induced increase in 3HAO activity was dose-dependently attenuated by the addition of ferritin, the main iron storage protein in the brain. The effect of iron was also readily prevented by N,N'-bis(2-hydroxybenzyl) ethylenediamine-N,N'-diacetic acid (HBED), a synthetic iron chelator with neuroprotective properties in vivo. All these effects were reproduced using neostriatal tissue obtained postmortem from normal individuals and patients with end-stage Huntington's disease. Our results suggest that QUIN levels and function in the mammalian brain might be tightly controlled by endogenous iron and proteins that regulate the bioavailability of iron.
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Affiliation(s)
- Erin K Stachowski
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, P.O. Box 21247, Baltimore, Maryland 21228, USA
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Williams R, Rohr AM, Wang WT, Choi IY, Lee P, Berman NEJ, Lynch SG, LeVine SM. Iron deposition is independent of cellular inflammation in a cerebral model of multiple sclerosis. BMC Neurosci 2011; 12:59. [PMID: 21699685 PMCID: PMC3128570 DOI: 10.1186/1471-2202-12-59] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 06/23/2011] [Indexed: 11/16/2022] Open
Abstract
Background Perivenular inflammation is a common early pathological feature in multiple sclerosis (MS). A recent hypothesis stated that CNS inflammation is induced by perivenular iron deposits that occur in response to altered blood flow in MS subjects. In order to evaluate this hypothesis, an animal model was developed, called cerebral experimental autoimmune encephalomyelitis (cEAE), which presents with CNS perivascular iron deposits. This model was used to investigate the relationship of iron deposition to inflammation. Methods In order to generate cEAE, mice were given an encephalitogen injection followed by a stereotactic intracerebral injection of TNF-α and IFN-γ. Control animals received encephalitogen followed by an intracerebral injection of saline, or no encephalitogen plus an intracerebral injection of saline or cytokines. Laser Doppler was used to measure cerebral blood flow. MRI and iron histochemistry were used to localize iron deposits. Additional histological procedures were used to localize inflammatory cell infiltrates, microgliosis and astrogliosis. Results Doppler analysis revealed that cEAE mice had a reduction in cerebral blood flow compared to controls. MRI revealed T2 hypointense areas in cEAE animals that spatially correlated with iron deposition around vessels and at some sites of inflammation as detected by iron histochemistry. Vessels with associated iron deposits were distributed across both hemispheres. Mice with cEAE had more iron-labeled vessels compared to controls, but these vessels were not commonly associated with inflammatory cell infiltrates. Some iron-laden vessels had associated microgliosis that was above the background microglial response, and iron deposits were observed within reactive microglia. Vessels with associated astrogliosis were more commonly observed without colocalization of iron deposits. Conclusion The findings indicate that iron deposition around vessels can occur independently of inflammation providing evidence against the hypothesis that iron deposits account for inflammatory cell infiltrates observed in MS.
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Affiliation(s)
- Rachel Williams
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA
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Choi EY, Park ZY, Choi EJ, Oh HM, Lee S, Choi SC, Lee KM, Im SH, Chun JS, Jun CD. Transcriptional regulation of IL-8 by iron chelator in human epithelial cells is independent from NF-κB but involves ERK1/2- and p38 kinase-dependent activation of AP-1. J Cell Biochem 2007; 102:1442-57. [PMID: 17471497 DOI: 10.1002/jcb.21367] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have shown that the bacterial iron chelator, deferoxamine (DFO), triggers inflammatory signals including the production of CXC chemokine IL-8, in human intestinal epithelial cells (IECs) by activating the ERK1/2 and p38 kinase pathways. In this study we investigated the mechanisms involved in IL-8 generation by DFO, focusing on the transcription factors involved and the roles of both mitogen-activated protein kinases (MAPKs) in the transcription factor activation. Treatment of human epithelial HT-29 cells with DFO markedly up-regulated the expression of the essential components of the transcription factor AP-1 at a transcriptional level, while it minimally affected the expression of the NF-kappaB subunits. DFO also induced AP-1-dependent transcriptional activity in HT-29 cells, and this activity was further augmented by the wild-type c-Jun transfection. In contrast, the AP-1 activity by DFO was markedly decreased by the dominant-negative c-Jun transfection. Electrophoretic mobility shift assays revealed that DFO increases the specific binding of AP-1 but not of NF-kappaB. Such AP-1 binding and transcriptional activities were blocked by the inhibitors of the ERK1/2 and p38 kinase pathways, suggesting that both mitogen-activated protein kinases (MAPKs) lie upstream of AP-1. Besides its action on AP-1, DFO also induced the specific binding of other transcription factors such as CREB and Egr-1. In summary, our results indicate that iron chelator-induced IL-8 generation in IECs involves activation of ERK1/2 and p38 kinase and downstream activation of AP-1. A possible link between iron status and two additional transcription factors, that is, CREB and Egr-1, rather than NF-kappaB, was also suggested.
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Affiliation(s)
- Eun-Young Choi
- Department of Life Science, Gwangju Institute of Science and Technology (GIST), Gwangju, Korea
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Choi EY, Lee S, Oh HM, Kim YD, Choi EJ, Kim SH, Kim SW, Choi SC, Jun CD. Involvement of protein kinase Cdelta in iron chelator-induced IL-8 production in human intestinal epithelial cells. Life Sci 2006; 80:436-45. [PMID: 17097691 DOI: 10.1016/j.lfs.2006.09.044] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2006] [Revised: 08/27/2006] [Accepted: 09/26/2006] [Indexed: 11/28/2022]
Abstract
We have shown that the bacterial iron chelator, deferoxamine (DFO), triggers inflammatory signals, including the production of CXC chemokine IL-8, in human intestinal epithelial cells (IECs) by activating ERK1/2 and p38 kinase pathways. In the present study, we show that PKCdelta, one of the novel protein kinase C (PKC) isoforms, involves in signal transduction pathways leading to DFO-induced IL-8 production. Pretreatment of human intestinal epithelial HT-29 cells with rottlerin showed remarkable inhibition of DFO-induced IL-8 production. In contrast, other PKC inhibitors such as Gö6976, Gö6983, GF109203X, and staurosporine revealed less or no inhibitory effects on DFO-induced IL-8 production, suggesting a potential role of PKCdelta. Accordingly, DFO caused phosphorylation of PKCdelta in the Thr505 and Ser643 residues in HT-29 cells. Transfection of dominant-negative PKCdelta vector inhibited DFO-induced PKCdelta phosphorylation as well as IL-8 promoter activity. In addition, suppression of endogenous PKCdelta by siRNA significantly reduced DFO-induced IL-8 production. Collectively, these results suggest that PKCdelta plays a pivotal role in signaling pathways leading to iron chelator-induced IL-8 production in human IECs.
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Affiliation(s)
- Eun-Young Choi
- Department of Life Science, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea
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Al-Waili NS, Butler GJ. Phototherapy and malignancy: Possible enhancement by iron administration and hyperbaric oxygen. Med Hypotheses 2006; 67:1148-58. [PMID: 16860490 DOI: 10.1016/j.mehy.2005.12.052] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Revised: 11/28/2005] [Accepted: 12/01/2005] [Indexed: 12/27/2022]
Abstract
Photodynamic therapy (PDT) is a new therapeutic approach for the treatment of malignant tumors. Hyperbaric oxygen (HBO(2)) shows beneficial effects in various modalities of cancer interventions. Tumor cells tend to accumulate large amount of iron. There is interaction between tissue content of oxygen, iron, free radical production and tissue damage. Accumulation of intracellular iron is necessary for the production of oxygen radicals. HBO(2) increases tissue oxygen and hydrogen peroxide production in the cells. Malignant cells require iron, and exhibit more transferrin receptors. The photodynamic sensitization of human leukemic cells is achieved with accumulation of porphyrins stimulated by 5-aminolaevulanic acid (ALA) plus hemin. Further, a significant improvement in tumor response is obtained when PDT is delivered during hyperoxygenation. When PDT is combined with hyperoxygenation, the hypoxic condition is improved and the cell killing rate at various time points after PDT is significantly enhanced. Photosensitization with use of porphyrins is used with HBO(2) and PDT for treatment of certain tumors. PDT with ALA is used for treatment of actinic keratosis (AK). The combination of iron administration (by injection or oral rout), hemin, or transferrin, as a source for iron, HBO(2) as a source of oxygen under pressure and PDT as a source of generating free-radical tissue damage may be useful in the treatment of tumors. The possibility of combining HBO(2), iron, light and local photosensitizers to overcome skin tumors deserve extensive laboratory and clinical research work. Conclusively, iron, HBO(2), and PDT may have synergistic effect to hamper tumor cells.
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Affiliation(s)
- Noori S Al-Waili
- Life Support Technologies, Inc. - NEWTechnologies, Inc., The Chronic Wound Management and Hyperbaric Medicine Center, The Mount Vernon Hospital, Sound Shore Health System, Mount Vernon, 7th Avenue, North 12, New York 10550, USA
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Choi EY, Kim EC, Oh HM, Kim S, Lee HJ, Cho EY, Yoon KH, Kim EA, Han WC, Choi SC, Hwang JY, Park C, Oh BS, Kim Y, Kimm KC, Park KI, Chung HT, Jun CD. Iron chelator triggers inflammatory signals in human intestinal epithelial cells: involvement of p38 and extracellular signal-regulated kinase signaling pathways. THE JOURNAL OF IMMUNOLOGY 2004; 172:7069-77. [PMID: 15153529 DOI: 10.4049/jimmunol.172.11.7069] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Competition for cellular iron (Fe) is a vital component of the interaction between host and pathogen. Most bacteria have an obligate requirement for Fe to sustain infection, growth, and survival in host. To obtain iron required for growth, many bacteria secrete iron chelators (siderophores). This study was undertaken to test whether a bacterial siderophore, deferoxamine (DFO), could trigger inflammatory signals in human intestinal epithelial cells as a single stimulus. Incubation of human intestinal epithelial HT-29 cells with DFO increased the expression of IL-8 mRNA, as well as the release of IL-8 protein. The signal transduction study revealed that both p38 and extracellular signal-regulated kinase-1/2 were significantly activated in response to DFO. Accordingly, the selective inhibitors for both kinases, either alone or in combination, completely abolished DFO-induced IL-8 secretion, indicating an importance of mitogen-activated protein kinases pathway. These proinflammatory effects of DFO were, in large part, mediated by activation of Na(+)/H(+) exchangers, because selective blockade of Na(+)/H(+) exchangers prevented the DFO-induced IL-8 production. Interestingly, however, DFO neither induced NF-kappaB activation by itself nor affected IL-1beta- or TNF-alpha-mediated NF-kappaB activation, suggesting a NF-kappaB-independent mechanism in DFO-induced IL-8 production. Global gene expression profiling revealed that DFO significantly up-regulates inflammation-related genes including proinflammatory genes, and that many of those genes are down-modulated by the selective mitogen-activated protein kinase inhibitors. Collectively, these results demonstrate that, in addition to bacterial products or cell wall components, direct chelation of host Fe by infected bacteria may also contribute to the evocation of host inflammatory responses.
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Affiliation(s)
- Eun-Young Choi
- Department of Microbiology and Immunology and Digestive Disease Research Institute, School of Medicine, Wonkwang University, Iksan, Chonbuk, Korea
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Barluzzi R, Saleppico S, Nocentini A, Boelaert JR, Neglia R, Bistoni F, Blasi E. Iron overload exacerbates experimental meningoencephalitis by Cryptococcus neoformans. J Neuroimmunol 2002; 132:140-6. [PMID: 12417444 DOI: 10.1016/s0165-5728(02)00324-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This study was aimed at investigating the effects of iron overload on the onset and outcome of cerebral cryptococcosis. To this purpose, iron dextran-administered mice were intracerebrally challenged with virulent melanogenic and avirulent non-melanogenic strains of Cryptococcus neoformans. The results shown here provide the first evidence that iron overload exacerbates the outcome of cryptococcal meningoencephalitis, irrespective of the fungal strain employed; pathogen colonization of the brain is facilitated, local cytokine response is delayed and/or prevented.
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Affiliation(s)
- Roberta Barluzzi
- Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia, Italy
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Malecki EA, Connor JR. The case for iron chelation and/or antioxidant therapy in Alzheimer's disease. Drug Dev Res 2002. [DOI: 10.1002/ddr.10105] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kwon KH, Kim KI, Jun WJ, Shin DH, Cho HY, Hong BS. In vitro and in vivo effects of macrophage-stimulatory polysaccharide from leaves of Perilla frutescens var. crispa. Biol Pharm Bull 2002; 25:367-71. [PMID: 11913535 DOI: 10.1248/bpb.25.367] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The crude polysaccharide (PFB-1) was isolated from the leaves of Perilla frutescens var. crispa by the sequential procedures with hot-water extraction, methanol reflux, and ethanol precipitation. It was further purified by anion column chromatography in order to obtain the partially purified polysaccharide (PFB-1-0). In the presence of PFB-1-0, strong cellular lysosomal enzyme activity of murine peritoneal macrophages was observed in vitro. Compared to bacterial lipopolysaccharide (LPS), its activity was relatively high. The in vitro phagocytic activity was enhanced by PFB-1-0 as the similar pattern in both gram-negative bacteria, E. coli, and gram-positive bacteria, S. aureus with a time-dependent manner. We also investigated the production of several mediators by murine peritoneal macrophages upon stimulation with PFB-1 (in vivo) or PFB-1-0 (in vitro). The levels of nitric oxide (NO) and tumor necrosis factor (TNF)-alpha were increased in the presence of PFB-1-0 in vitro. The PFB-1 stimulated the production of interleukin (IL)-6 and granulocyte-macrophage colony-stimulating factor (GM-CSF) in vivo. Results suggest that the polysaccharide from P. frutescens var. crispa represents an immunopotentiator and biological response modifiers in vitro and in vivo levels.
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Affiliation(s)
- Ki Han Kwon
- Graduate School of Biotechnology, Korea University, Seoul
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30
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Kim KI, Shin KS, Jun WJ, Hong BS, Shin DH, Cho HY, Chang HI, Yoo SM, Yang HC. Effects of polysaccharides from rhizomes of Curcuma zedoaria on macrophage functions. Biosci Biotechnol Biochem 2001; 65:2369-77. [PMID: 11791707 DOI: 10.1271/bbb.65.2369] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The effects of Curcuma zedoaria, which is used as a condiment, in perfumery, and as a medicine, on immune response were investigated by measuring macrophage-stimulating activity in macrophages and RAW 264.7 cells. In this study, CZ-1 and CZ-1-III, the fractions partially purified from C. zedoaria, had a strong, dose-dependent lysosomal enzyme activity. It was suggested that active portions of CZ-1-III were polysaccharides rather than proteins. Phagocytic activity increased as a similar pattern in both the gram-negative and gram-positive bacteria, time-dependently. It was demonstrated that CZ-1-III can augment the oxygen burst response but had an even higher activity in vivo than in vitro. Also a significant increase of H2O2, NO, and TNF-alpha production was observed. However, the production of TNF-alpha at the concentration of 1,000 microg/ml decreased. These data suggested that C. zedoaria had macrophage-stimulating activity and the possibility of being used as a biological response modifier.
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Affiliation(s)
- K I Kim
- Graduate School of Biotechnology, Korea University, Seoul
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31
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Cheepsunthorn P, Radov L, Menzies S, Reid J, Connor JR. Characterization of a novel brain-derived microglial cell line isolated from neonatal rat brain. Glia 2001; 35:53-62. [PMID: 11424192 DOI: 10.1002/glia.1070] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We observed highly aggressively proliferating immortalized (HAPI) cells growing in cultures that had been enriched for microglia. The cells were initially obtained from mixed glial cultures prepared from 3-day-old rat brains. HAPI cells are typically round with few or no processes when cultured in 10% serum containing medium. As the percentage of serum in the medium is decreased, the HAPI cells have more processes. HAPI cells stain for the isolectin B4, OX-42, and GLUT5, which are markers for microglial cells, but the cells do not immunolabel with A2B5, a marker of cells in the oligodendroglial cell lineage, or with the astrocyte-specific marker, glial fibrillary aciidic protein (GFAP). In addition, HAPI cells are capable of phagocytosis. We conclude that HAPI cells are of microglia/macrophage lineage. Exposing HAPI cells to lipopolysaccharide (LPS) induces the mRNAs for tumor necrosis factor-alpha (TNF-alpha) and inducible nitric oxide synthase (iNOS). LPS exposure also induces secretion of TNF-alpha and production of nitric oxide (NO) in HAPI cells. Because activation of microglia is associated with an increase in iron accumulation and ferritin expression, we tested the hypothesis that iron status affects the production of TNF-alpha and NO. Our studies demonstrate that both iron chelation and iron loading diminished the LPS-induced effect of TNF-alpha and NO. The results of this study indicate that HAPI cells possess the characteristics of microglia/brain macrophages, providing an alternative cell culture model for the study of microglia. In addition, we demonstrate that the activation of microglial cells could be modified by iron.
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Affiliation(s)
- P Cheepsunthorn
- Department of Neuroscience and Anatomy, M.S. Hershey Medical Center, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania, USA
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Tanji K, Imaizumi T, Matsumiya T, Itaya H, Fujimoto K, Cui X, Toki T, Ito E, Yoshida H, Wakabayashi K, Satoh K. Desferrioxamine, an iron chelator, upregulates cyclooxygenase-2 expression and prostaglandin production in a human macrophage cell line. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1530:227-35. [PMID: 11239825 DOI: 10.1016/s1388-1981(01)00089-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Prostaglandins (PGs) play regulatory roles in a variety of physiological and pathological processes, including the immune response, cytoprotection and inflammation. Desferrioxamine (DFX), an iron chelator, is known to reduce free radical-mediated cell injury and to upregulate certain inflammatory mediators. We investigated the effects of DFX on the production of PGs and the expression of cyclooxygenase-2 (COX-2), the rate-limiting enzyme in the synthesis of PGs, using a human macrophage cell line, U937. Our results showed that COX-2 expression and PGE(2) production are upregulated by DFX treatment and that this upregulation is dependent on both COX-2 promoter activity and alteration of mRNA stability. COX-2 promoter activity may be, at least in part, mediated by activation of the extracellular signal-regulated kinase pathway. These findings suggest that iron metabolism may regulate inflammatory processes by modulating PGs as well as other inflammatory mediators.
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Affiliation(s)
- K Tanji
- Department of Molecular Biology, Institute of Brain Science, Hirosaki University School of Medicine, Japan.
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Saleppico S, Boelaert JR, Omodeo Salè F, Mazzolla R, Morucci P, Bistoni F, Blasi E. Differential effects of iron load on basal and interferon-gamma plus lipopolysaccharide enhance anticryptococcal activity by the murine microglial cell line BV-2. J Neuroimmunol 1999; 93:102-7. [PMID: 10378873 DOI: 10.1016/s0165-5728(98)00206-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Here we evaluated the influence of intracellular iron levels on the constitutive and interferon (IFN)-gamma plus lipopolysaccharide (LPS) enhanced anticryptococcal activity by the murine microglial cell line BV-2. We demonstrated that iron loading via ferric nitrilotriacetate (FeNTA) resulted in a significant increase in the constitutive levels of anticryptococcal activity, while the enhancing effects by IFN-gamma plus LPS were prevented. Accordingly, a major increase was observed in the levels of thiobarbituric reactive substance (TBARS) produced upon iron loading under basal conditions, whereas IFN-gamma plus LPS treatment, that per se did not affect TBARS production, prevented by about 50% the enhancement otherwise occurring in response to iron loading. The potential involvement of multiple effector system and their relation to intracellular iron will be discussed.
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Affiliation(s)
- S Saleppico
- Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Italy
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Abstract
Iron is an oxidant as well as a nutrient for invading microbial and neoplastic cells. Excessive iron in specific tissues and cells (iron loading) promotes development of infection, neoplasia, cardiomyopathy, arthropathy, and various endocrine and possibly neurodegenerative disorders. To contain and detoxify the metal, hosts have evolved an iron withholding defense system, but the system can be compromised by numerous factors. An array of behavioral, medical, and immunologic methods are in place or in development to strengthen iron withholding. Routine screening for iron loading could provide valuable information in epidemiologic, diagnostic, prophylactic, and therapeutic studies of emerging infectious diseases.
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