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Marques-da-Silva D, Lagoa R. Rafting on the Evidence for Lipid Raft-like Domains as Hubs Triggering Environmental Toxicants' Cellular Effects. Molecules 2023; 28:6598. [PMID: 37764374 PMCID: PMC10536579 DOI: 10.3390/molecules28186598] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 09/07/2023] [Accepted: 09/07/2023] [Indexed: 09/29/2023] Open
Abstract
The plasma membrane lipid rafts are cholesterol- and sphingolipid-enriched domains that allow regularly distributed, sub-micro-sized structures englobing proteins to compartmentalize cellular processes. These membrane domains can be highly heterogeneous and dynamic, functioning as signal transduction platforms that amplify the local concentrations and signaling of individual components. Moreover, they participate in cell signaling routes that are known to be important targets of environmental toxicants affecting cell redox status and calcium homeostasis, immune regulation, and hormonal functions. In this work, the evidence that plasma membrane raft-like domains operate as hubs for toxicants' cellular actions is discussed, and suggestions for future research are provided. Several studies address the insertion of pesticides and other organic pollutants into membranes, their accumulation in lipid rafts, or lipid rafts' disruption by polychlorinated biphenyls (PCBs), benzo[a]pyrene (B[a]P), and even metals/metalloids. In hepatocytes, macrophages, or neurons, B[a]P, airborne particulate matter, and other toxicants caused rafts' protein and lipid remodeling, oxidative changes, or amyloidogenesis. Different studies investigated the role of the invaginated lipid rafts present in endothelial cells in mediating the vascular inflammatory effects of PCBs. Furthermore, in vitro and in vivo data strongly implicate raft-localized NADPH oxidases, the aryl hydrocarbon receptor, caveolin-1, and protein kinases in the toxic mechanisms of occupational and environmental chemicals.
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Affiliation(s)
- Dorinda Marques-da-Silva
- LSRE—Laboratory of Separation and Reaction Engineering and LCM—Laboratory of Catalysis and Materials, School of Management and Technology, Polytechnic Institute of Leiria, Morro do Lena-Alto do Vieiro, 2411-901 Leiria, Portugal;
- ALiCE—Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
- School of Technology and Management, Polytechnic Institute of Leiria, Morro do Lena-Alto do Vieiro, 2411-901 Leiria, Portugal
| | - Ricardo Lagoa
- LSRE—Laboratory of Separation and Reaction Engineering and LCM—Laboratory of Catalysis and Materials, School of Management and Technology, Polytechnic Institute of Leiria, Morro do Lena-Alto do Vieiro, 2411-901 Leiria, Portugal;
- ALiCE—Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
- School of Technology and Management, Polytechnic Institute of Leiria, Morro do Lena-Alto do Vieiro, 2411-901 Leiria, Portugal
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2
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O’Day PA, Pattammattel A, Aronstein P, Leppert VJ, Forman HJ. Iron Speciation in Respirable Particulate Matter and Implications for Human Health. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:7006-7016. [PMID: 35235749 PMCID: PMC9179659 DOI: 10.1021/acs.est.1c06962] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 01/19/2022] [Accepted: 02/08/2022] [Indexed: 06/14/2023]
Abstract
Particulate matter (PM) air pollution poses a major global health risk, but the role of iron (Fe) is not clearly defined because chemistry at the particle-cell interface is often not considered. Detailed spectromicroscopy characterizations of PM2.5 samples from the San Joaquin Valley, CA identified major Fe-bearing components and estimated their relative proportions. Iron in ambient PM2.5 was present in spatially and temporally variable mixtures, mostly as Fe(III) oxides and phyllosilicates, but with significant fractions of metallic iron (Fe(0)), Fe(II,III) oxide, and Fe(III) bonded to organic carbon. Fe(0) was present as aggregated, nm-sized particles that comprised up to ∼30% of the Fe spectral fraction. Mixtures reflect anthropogenic and geogenic particles subjected to environmental weathering, but reduced Fe in PM originates from anthropogenic sources, likely as abrasion products. Possible mechanistic pathways involving Fe(0) particles and mixtures of Fe(II) and Fe(III) surface species may generate hydrogen peroxide and oxygen-centered radical species (hydroxyl, hydroperoxyl, or superoxide) in Fenton-type reactions. From a health perspective, PM mixtures with reduced and oxidized Fe will have a disproportionate effect in cellular response after inhalation because of their tendency to shuttle electrons and produce oxidants and electrophiles that induce inflammation and oxidative stress.
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Affiliation(s)
- Peggy A. O’Day
- Life
and Environmental Sciences Department and the Sierra Nevada Research
Institute, University of California, Merced, California 95343, United States
- Environmental
Systems Graduate Program, University of
California, Merced, 95343, United States
| | - Ajith Pattammattel
- Life
and Environmental Sciences Department and the Sierra Nevada Research
Institute, University of California, Merced, California 95343, United States
- NSLS
II, Brookhaven National Laboratory, Upton, New York 11973 United States
| | - Paul Aronstein
- Environmental
Systems Graduate Program, University of
California, Merced, 95343, United States
| | - Valerie J. Leppert
- Materials
Science and Engineering Department, University
of California, Merced, California 95343, United States
| | - Henry Jay Forman
- Life
and Environmental Sciences Department and the Sierra Nevada Research
Institute, University of California, Merced, California 95343, United States
- Leonard
Davis School of Gerontology, University
of Southern California, Los Angeles, California 90089, United States
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3
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Kang E, Park JE, Seo Y, Han JS. ( E)-5-hydroxy-7-methoxy-3-(2'-hydroxybenzyl)-4-chromanone isolated from Portulaca oleracea L. suppresses LPS-induced inflammation in RAW 264.7 macrophages by downregulating inflammatory factors. Immunopharmacol Immunotoxicol 2021; 43:611-621. [PMID: 34388059 DOI: 10.1080/08923973.2021.1963271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
CONTEXT Portulaca oleracea L. is herbaceous succulent annual plant, which belongs to the Portulacaceae family. Many studies have shown its wide spectrum of pharmacological activities such as anti-cancer and anti-diabetic effects. OBJECTIVES The objective of this study was to identify the anti-inflammatory effects of HM-chromanone isolated from Portulaca oleracea L. in LPS-stimulated RAW 264.7 macrophages. MATERIALS AND METHODS LPS (1 μg/ml)-stimulated mouse RAW 264.7 macrophages were used to assess the anti-inflammatory effect of HM-chromanone (10-50 μM). Cell viability was evaluated by MTT assay. In addition, the production of intracellular ROS, superoxide anion, lipid peroxide, NO, and PGE2, and activity of antioxidant enzymes were analyzed. The expressions of iNOS, COX-2, IκB, NF-κB, TNF-α, IL-1β and IL-6 were evaluated by western blot analysis. RESULTS HM-chromanone has demonstrated that there is no significant cytotoxic effect on the viability of RAW 264.7 macrophages. In LPS-stimulated RAW 264.7 cells, HM-chromanone treatment was found to significantly inhibit the production of intracellular ROS, superoxide anion and lipid peroxide, while enhancing the activity of antioxidant enzymes such as SOD, catalase, and GSH-px. Additionally, HM-chromanone treatment was observed to inhibit NO and PGE2 production by inhibiting the expression of iNOS and COX-2. Subsequently, HM-chromanone was observed to significantly suppress LPS-induced expression of IκB, NF-κB, TNF-α, IL-1β and IL-6. DISCUSSION AND CONCLUSION Overall, our results suggested that HM-chromanone suppresses LPS-induced inflammation in RAW 264.7 macrophages by downregulating the expression of inflammatory factors.
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Affiliation(s)
- Eunji Kang
- Department of Food Science and Nutrition, Pusan National University, Busan, Republic of Korea
| | - Jae Eun Park
- Department of Food Science and Nutrition, Pusan National University, Busan, Republic of Korea
| | - Youngwan Seo
- Division of Marine Bioscience, Korea Maritime and Ocean University, Busan, Republic of Korea
| | - Ji Sook Han
- Department of Food Science and Nutrition, Pusan National University, Busan, Republic of Korea
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4
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Pattammattel A, Leppert VJ, Aronstein P, Robinson M, Mousavi A, Sioutas C, Forman HJ, O’Day PA. Iron Speciation in Particulate Matter (PM 2.5) from Urban Los Angeles Using Spectro-microscopy Methods. ATMOSPHERIC ENVIRONMENT (OXFORD, ENGLAND : 1994) 2021; 245:117988. [PMID: 33223923 PMCID: PMC7673293 DOI: 10.1016/j.atmosenv.2020.117988] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The speciation, oxidation states, and relative abundance of iron (Fe) phases in PM2.5 samples from two locations in urban Los Angeles were investigated using a combination of bulk and spatially resolved, element-specific spectroscopy and microscopy methods. Synchrotron X-ray absorption spectroscopy (XAS) of bulk samples in situ (i.e., without extraction or digestion) was used to quantify the relative fractions of major Fe phases, which were corroborated by spatially resolved spectro-microscopy measurements. Ferrihydrite (amorphous Fe(III)-hydroxide) comprised the largest Fe fraction (34-52%), with hematite (α-Fe2O3; 13-23%) and magnetite (Fe3O4; 10-24%) identified as major crystalline oxide components. An Fe-bearing phyllosilicate fraction (16-23%) was fit best with a reference spectrum of a natural illite/smectite mineral, and metallic Fe(0) was a relatively small (2-6%) but easily identified component. Sizes, morphologies, oxidation state, and trace element compositions of Fe-bearing PM from electron microscopy, electron energy loss spectroscopy (EELS), and scanning transmission X-ray microscopy (STXM) revealed variable and heterogeneous mixtures of Fe species and phases, often associated with carbonaceous material with evidence of surface oxidation. Ferrihydrite (or related Fe(III) hydroxide phases) was ubiquitous in PM samples. It forms as an oxidation or surface alteration product of crystalline Fe phases, and also occurs as coatings or nanoparticles dispersed with other phases as a result of environmental dissolution and re-precipitation reactions. The prevalence of ferrihydrite (and adsorbed Fe(III) has likely been underestimated in studies of ambient PM because it is non-crystalline, non-magnetic, more soluble than crystalline phases, and found in complex mixtures. Review of potential sources of different particle types suggests that the majority of Fe-bearing PM from these urban sites originates from anthropogenic activities, primarily abrasion products from vehicle braking systems and engine emissions from combustion and/or wear. These variable mixtures have a high probability for electron transfer reactions between Fe, redox-active metals such as copper, and reactive carbon species such as quinones. Our findings suggest the need to assess biological responses of specific Fe-bearing phases both individually and in combination to unravel mechanisms of adverse health effects of particulate Fe.
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Affiliation(s)
- Ajith Pattammattel
- Sierra Nevada Research Institute and School of Natural Sciences, University of California, Merced, 95343, USA
| | | | - Paul Aronstein
- Environmental Systems Program, University of California, Merced, 95343, USA
| | - Matthew Robinson
- School of Engineering, University of California, Merced, 95343, USA
| | - Amirhosein Mousavi
- Viterbi School of Engineering, University of Southern California, Los Angeles, USA
| | - Constantinos Sioutas
- Viterbi School of Engineering, University of Southern California, Los Angeles, USA
| | - Henry Jay Forman
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, USA
| | - Peggy A. O’Day
- Sierra Nevada Research Institute and School of Natural Sciences, University of California, Merced, 95343, USA
- Environmental Systems Program, University of California, Merced, 95343, USA
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5
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Forman HJ, Zhang H. Targeting oxidative stress in disease: promise and limitations of antioxidant therapy. Nat Rev Drug Discov 2021; 20:689-709. [PMID: 34194012 PMCID: PMC8243062 DOI: 10.1038/s41573-021-00233-1] [Citation(s) in RCA: 952] [Impact Index Per Article: 317.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/12/2021] [Indexed: 02/06/2023]
Abstract
Oxidative stress is a component of many diseases, including atherosclerosis, chronic obstructive pulmonary disease, Alzheimer disease and cancer. Although numerous small molecules evaluated as antioxidants have exhibited therapeutic potential in preclinical studies, clinical trial results have been disappointing. A greater understanding of the mechanisms through which antioxidants act and where and when they are effective may provide a rational approach that leads to greater pharmacological success. Here, we review the relationships between oxidative stress, redox signalling and disease, the mechanisms through which oxidative stress can contribute to pathology, how antioxidant defences work, what limits their effectiveness and how antioxidant defences can be increased through physiological signalling, dietary components and potential pharmaceutical intervention.
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Affiliation(s)
- Henry Jay Forman
- University of California Merced, Merced, CA, USA. .,Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA.
| | - Hongqiao Zhang
- grid.42505.360000 0001 2156 6853Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA USA
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6
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Natarajan P, Tomich JM. Understanding the influence of experimental factors on bio-interactions of nanoparticles: Towards improving correlation between in vitro and in vivo studies. Arch Biochem Biophys 2020; 694:108592. [PMID: 32971033 PMCID: PMC7503072 DOI: 10.1016/j.abb.2020.108592] [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: 06/18/2020] [Revised: 09/16/2020] [Accepted: 09/18/2020] [Indexed: 12/17/2022]
Abstract
Bionanotechnology has developed rapidly over the past two decades, owing to the extensive and versatile, functionalities and applicability of nanoparticles (NPs). Fifty-one nanomedicines have been approved by FDA since 1995, out of the many NPs based formulations developed to date. The general conformation of NPs consists of a core with ligands coating their surface, that stabilizes them and provides them with added functionalities. The physicochemical properties, especially the surface composition of NPs influence their bio-interactions to a large extent. This review discusses recent studies that help understand the nano-bio interactions of iron oxide and gold NPs with different surface compositions. We discuss the influence of the experimental factors on the outcome of the studies and, thus, the importance of standardization in the field of nanotechnology. Recent studies suggest that with careful selection of experimental parameters, it is possible to improve the positive correlation between in vitro and in vivo studies. This provides a fundamental understanding of the NPs which helps in assessing their potential toxic side effects and may aid in manipulating them further to improve their biocompatibility and biosafety.
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7
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Shkirkova K, Lamorie-Foote K, Connor M, Patel A, Barisano G, Baertsch H, Liu Q, Morgan TE, Sioutas C, Mack WJ. Effects of ambient particulate matter on vascular tissue: a review. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2020; 23:319-350. [PMID: 32972334 PMCID: PMC7758078 DOI: 10.1080/10937404.2020.1822971] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Fine and ultra-fine particulate matter (PM) are major constituents of urban air pollution and recognized risk factors for cardiovascular diseases. This review examined the effects of PM exposure on vascular tissue. Specific mechanisms by which PM affects the vasculature include inflammation, oxidative stress, actions on vascular tone and vasomotor responses, as well as atherosclerotic plaque formation. Further, there appears to be a greater PM exposure effect on susceptible individuals with pre-existing cardiovascular conditions.
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Affiliation(s)
| | - Krista Lamorie-Foote
- Zilkha Neurogenetic Institute, University of Southern California
- Keck School of Medicine, University of Southern California
| | - Michelle Connor
- Zilkha Neurogenetic Institute, University of Southern California
- Keck School of Medicine, University of Southern California
| | - Arati Patel
- Zilkha Neurogenetic Institute, University of Southern California
- Keck School of Medicine, University of Southern California
| | | | - Hans Baertsch
- Zilkha Neurogenetic Institute, University of Southern California
- Keck School of Medicine, University of Southern California
| | - Qinghai Liu
- Zilkha Neurogenetic Institute, University of Southern California
| | - Todd E. Morgan
- Leonard Davis School of Gerontology, University of Southern California
| | - Constantinos Sioutas
- Department of Civil and Environmental Engineering, Viterbi School of Engineering, University of Southern California
| | - William J. Mack
- Zilkha Neurogenetic Institute, University of Southern California
- Leonard Davis School of Gerontology, University of Southern California
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8
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Haghani A, Johnson R, Safi N, Zhang H, Thorwald M, Mousavi A, Woodward NC, Shirmohammadi F, Coussa V, Wise JP, Forman HJ, Sioutas C, Allayee H, Morgan TE, Finch CE. Toxicity of urban air pollution particulate matter in developing and adult mouse brain: Comparison of total and filter-eluted nanoparticles. ENVIRONMENT INTERNATIONAL 2020; 136:105510. [PMID: 32004873 PMCID: PMC7063839 DOI: 10.1016/j.envint.2020.105510] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/17/2020] [Accepted: 01/17/2020] [Indexed: 05/19/2023]
Abstract
Air pollution (AirP) is associated with many neurodevelopmental and neurological disorders in human populations. Rodent models show similar neurotoxic effects of AirP particulate matter (PM) collected by different methods or from various sources. However, controversies continue on the identity of the specific neurotoxic components and mechanisms of neurotoxicity. We collected urban PM by two modes at the same site and time: direct collection as an aqueous slurry (sPM) versus a nano-sized sub-fraction of PM0.2 that was eluted from filters (nPM). The nPM lacks water-insoluble PAHs (polycyclic aromatic hydrocarbons) and is depleted by >50% in bioactive metals (e.g., copper, iron, nickel), inorganic ions, black carbon, and other organic compounds. Three biological models were used: in vivo exposure of adult male mice to re-aerosolized nPM and sPM for 3 weeks, gestational exposure, and glial cell cultures. In contrast to larger inflammatory responses of sPM in vitro, cerebral cortex responses of mice to sPM and nPM largely overlapped for adult and gestational exposures. Adult brain responses included induction of IFNγ and NF-κB. Gestational exposure to nPM and sPM caused equivalent depressive behaviors. Responses to nPM and sPM diverged for cerebral cortex glutamate receptor mRNA, systemic fat gain and insulin resistance. The shared toxic responses of sPM with nPM may arise from shared transition metals and organics. In contrast, gestational exposure to sPM but not nPM, decreased glutamatergic mRNAs, which may be attributed to PAHs. We discuss potential mechanisms in the overlap between nPM and sPM despite major differences in bulk chemical composition.
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Affiliation(s)
- Amin Haghani
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, United States
| | - Richard Johnson
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, United States
| | - Nikoo Safi
- Center for Cancer Prevention and Translational Genomics at the Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Hongqiao Zhang
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, United States
| | - Max Thorwald
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, United States
| | - Amirhosein Mousavi
- Viterbi School of Engineering, University of Southern California, Los Angeles, CA, United States
| | - Nicholas C Woodward
- Department of Preventive Medicine, University of Southern California, Los Angeles, CA, United States
| | - Farimah Shirmohammadi
- Viterbi School of Engineering, University of Southern California, Los Angeles, CA, United States
| | - Valerio Coussa
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, United States
| | - John P Wise
- School of Medicine, University of Louisville, Louisville, KY, United States
| | - Henry Jay Forman
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, United States
| | - Constantinos Sioutas
- Viterbi School of Engineering, University of Southern California, Los Angeles, CA, United States
| | - Hooman Allayee
- Department of Preventive Medicine, University of Southern California, Los Angeles, CA, United States
| | - Todd E Morgan
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, United States
| | - Caleb E Finch
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, United States; Dornsife College, University of Southern California, Los Angeles, CA, United States.
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9
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Cacciottolo M, Morgan TE, Saffari AA, Shirmohammadi F, Forman HJ, Sioutas C, Finch CE. Traffic-related air pollutants (TRAP-PM) promote neuronal amyloidogenesis through oxidative damage to lipid rafts. Free Radic Biol Med 2020; 147:242-251. [PMID: 31883973 PMCID: PMC7075030 DOI: 10.1016/j.freeradbiomed.2019.12.023] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 12/10/2019] [Accepted: 12/20/2019] [Indexed: 12/21/2022]
Abstract
Traffic-related air pollution particulate matter (TRAP-PM) is associated with increased risk of Alzheimer Disease (AD). Rodent models respond to nano-sized TRAP-PM (nPM) with increased production of amyloid Aβ peptides, concurrently with oxidative damage. Because pro-Aβ processing of the amyloid precursor protein (APP) occurs on subcellular lipid rafts, we hypothesized that oxidative stress from nPM exposure would alter lipid rafts to favor Aβ production. This hypothesis was tested with J20 mice and N2a cells transgenic for hAPPswe (familial AD). Exposure of J20-APPswe mice to nPM for 150 h caused increased lipid oxidation (4-HNE) and increased the pro-amyloidogenic processing of APP in lipid raft fractions in cerebral cortex; the absence of these changes in cerebellum parallels the AD brain region selectivity for Aβ deposits. In vitro, nPM induced similar oxidative responses in N2a-APPswe cells, with dose-dependent production of NO, oxidative damage (4-HNE, 3NT), and lipid raft alterations of APP with increased Aβ peptides. The antioxidant N-acetyl-cysteine (NAC) attenuated nPM-induced oxidative damage and lipid raft alterations of APP processing. These findings identify neuronal lipid rafts as novel targets of oxidative damage in the pro-amyloidogenic effects of air pollution.
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Affiliation(s)
- Mafalda Cacciottolo
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Todd E Morgan
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Arian A Saffari
- Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Farimah Shirmohammadi
- Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Henry Jay Forman
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Costantinos Sioutas
- Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Caleb E Finch
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA; Dornsife College, Dept. Biological Sciences, University of Southern California, Los Angeles, CA, USA.
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10
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Zhang H, Haghani A, Mousavi AH, Cacciottolo M, D'Agostino C, Safi N, Sowlat MH, Sioutas C, Morgan TE, Finch CE, Forman HJ. Cell-based assays that predict in vivo neurotoxicity of urban ambient nano-sized particulate matter. Free Radic Biol Med 2019; 145:33-41. [PMID: 31542466 PMCID: PMC7207020 DOI: 10.1016/j.freeradbiomed.2019.09.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/12/2019] [Accepted: 09/19/2019] [Indexed: 12/13/2022]
Abstract
Exposure to urban ambient particulate matter (PM) is associated with risk of Alzheimer's disease and accelerated cognitive decline in normal aging. Assessment of the neurotoxic effects caused by urban PM is complicated by variations of composition from source, location, and season. We compared several in vitro cell-based assays in relation to their in vivo neurotoxicity for NF-κB transcriptional activation, nitric oxide induction, and lipid peroxidation. These studies compared batches of nPM, a nanosized subfraction of PM2.5, extracted as an aqueous suspension, used in prior studies. In vitro activities were compared with in vivo responses of mice chronically exposed to the same batch of nPM. The potency of nPM varied widely between batches for NF-κB activation, analyzed with an NF-κB reporter in human monocytes. Three independently collected batches of nPM had corresponding differences to responses of mouse cerebral cortex to chronic nPM inhalation, for levels of induction of pro-inflammatory cytokines, microglial activation (Iba1), and soluble Aβ40 & -42 peptides. The in vitro responses of BV2 microglia for NO-production and lipid peroxidation also differed by nPM batch, but did not correlate with in vivo responses. These data confirm that batches of nPM can differ widely in toxicity. The in vitro NF-κB reporter assay offers a simple, high throughput screening method to predict the in vivo neurotoxic effects of nPM exposure.
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Affiliation(s)
- Hongqiao Zhang
- Leonard Davis School of Gerontology, University of Southern California, USA
| | - Amin Haghani
- Leonard Davis School of Gerontology, University of Southern California, USA
| | - Amirhosein H Mousavi
- Viterbi School of Engineering, University of Southern California, Los Angeles, CA, 90089, USA
| | | | - Carla D'Agostino
- Leonard Davis School of Gerontology, University of Southern California, USA
| | - Nikoo Safi
- Center for Cancer Prevention and Translational Genomics at the Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Mohammad H Sowlat
- Leonard Davis School of Gerontology, University of Southern California, USA
| | - Constantinos Sioutas
- Viterbi School of Engineering, University of Southern California, Los Angeles, CA, 90089, USA
| | - Todd E Morgan
- Leonard Davis School of Gerontology, University of Southern California, USA
| | - Caleb E Finch
- Leonard Davis School of Gerontology, University of Southern California, USA; Dept. Neurobiology, Dornsife College, USA
| | - Henry Jay Forman
- Leonard Davis School of Gerontology, University of Southern California, USA.
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11
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Pattammattel A, Leppert VJ, Forman HJ, O’Day PA. Surface characterization and chemical speciation of adsorbed iron(iii) on oxidized carbon nanoparticles. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2019; 21:548-563. [PMID: 30702742 PMCID: PMC6426675 DOI: 10.1039/c8em00545a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Carbonaceous nanomaterials represent a significant portion of ultra-fine airborne particulate matter, and iron is the most abundant transition metal in air particles. Owing to their high surface area and atmospheric oxidation, carbon nanoparticles (CNP) are enriched with surface carbonyl functional groups and act as a host for metals and small molecules. Using a synthetic model, concentration-dependent changes in the chemical speciation of iron adsorbed on oxidized carbon surfaces were investigated by a combination of X-ray and electron microscopic and spectroscopic methods. Carbon K-edge absorption spectra demonstrated that the CNP surface was enriched with carboxylic acid groups after chemical oxidation but that microporosity was unchanged. Oxidized CNP showed a high affinity for sorption of Fe(iii) from solution (75-95% uptake) and spectroscopic measurements confirmed a 3+ oxidation state of Fe on CNP irrespective of surface loading. The bonding of adsorbed Fe(iii) at variable loadings was determined by iron K-edge X-ray absorption spectroscopy. At low loadings (3 and 10 μmol Fe m-2 CNP), mononuclear Fe was octahedrally coordinated to oxygen atoms of carboxylate groups. As Fe surface coverage increased (21 and 31 μmol Fe m-2 CNP), Fe-Fe backscatters were observed at interatomic distances indicating iron (oxy)hydroxide particle formation on CNP. Electron-donating surface carboxylate groups on CNP coordinated and stabilized mononuclear Fe(iii). Saturation of high-affinity sites may have promoted hydroxide particle nucleation at higher loading, demonstrating that the chemical form of reactive metal ions may change with surface concentration and degree of CNP surface oxidation. Model systems such as those discussed here, with controlled surface properties and known chemical speciation of adsorbed metals, are needed to establish structure-activity models for toxicity assessments of environmentally relevant nanoparticles.
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Affiliation(s)
- Ajith Pattammattel
- School of Natural Sciences and Sierra Nevada Research Institute, University of California, Merced, California, USA
- Corresponding authors ,
| | - Valerie J. Leppert
- School of Engineering, University of California, Merced, California, USA
| | - Henry Jay Forman
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, California, USA
| | - Peggy A. O’Day
- School of Natural Sciences and Sierra Nevada Research Institute, University of California, Merced, California, USA
- Corresponding authors ,
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12
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Yazdimamaghani M, Moos PJ, Dobrovolskaia MA, Ghandehari H. Genotoxicity of amorphous silica nanoparticles: Status and prospects. NANOMEDICINE : NANOTECHNOLOGY, BIOLOGY, AND MEDICINE 2019; 16:106-125. [PMID: 30529789 PMCID: PMC6455809 DOI: 10.1016/j.nano.2018.11.013] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 11/19/2018] [Accepted: 11/27/2018] [Indexed: 12/11/2022]
Abstract
Amorphous silica nanoparticles (SNPs) are widely used in biomedical applications and consumer products. Little is known, however, about their genotoxicity and potential to induce gene expression regulation. Despite recent efforts to study the underlying mechanisms of genotoxicity of SNPs, inconsistent results create a challenge. A variety of factors determine particle-cell interactions and underlying mechanisms. Further, high-throughput studies are required to carefully assess the impact of silica nanoparticle physicochemical properties on induction of genotoxic response in different cell lines and animal models. In this article, we review the strategies available for evaluation of genotoxicity of nanoparticles (NPs), survey current status of silica nanoparticle gene alteration and genotoxicity, discuss particle-mediated inflammation as a contributing factor to genotoxicity, identify existing gaps and suggest future directions for this research.
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Affiliation(s)
- Mostafa Yazdimamaghani
- Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, Utah, United States; Utah Center for Nanomedicine, Nano Institute of Utah, University of Utah, Salt Lake City, Utah, United States
| | - Philip J Moos
- Utah Center for Nanomedicine, Nano Institute of Utah, University of Utah, Salt Lake City, Utah, United States; Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, United States
| | - Marina A Dobrovolskaia
- Nanotechnology Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research sponsored by the National Cancer Institute, Frederick, Maryland, United States
| | - Hamidreza Ghandehari
- Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, Utah, United States; Utah Center for Nanomedicine, Nano Institute of Utah, University of Utah, Salt Lake City, Utah, United States; Department of Bioengineering, University of Utah, Salt Lake City, Utah, United States.
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13
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Forman HJ, Finch CE. A critical review of assays for hazardous components of air pollution. Free Radic Biol Med 2018; 117:202-217. [PMID: 29407794 PMCID: PMC5845809 DOI: 10.1016/j.freeradbiomed.2018.01.030] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 01/22/2018] [Accepted: 01/25/2018] [Indexed: 12/11/2022]
Abstract
Increased mortality and diverse morbidities are globally associated with exposure to ambient air pollution (AAP), cigarette smoke (CS), and household air pollution (HAP). The AAP-CS-HAP aerosols present heterogeneous particulate matter (PM) of diverse chemical and physical characteristics. Some epidemiological models have assumed the same health hazards by PM weight for AAP, CS, and HAP regardless of the composition. While others have recognized that biological activities and toxicity will vary with components, we focus particularly on oxidation because of its major role in assay outcomes. Our review of PM assays considers misinterpretations of some chemical measures used for oxidative activity. Overall, there is low consistency across chemical and cell-based assays for oxidative and inflammatory activity. We also note gaps in understanding how much airborne PM of various sizes enter cells and organs. For CS, the body burden per cigarette may be much below current assumptions. Synergies shown for health hazards of AAP and CS suggest crosstalk in detoxification pathways mediated by AHR, NF-κB, and Nrf2. These complex genomic and biochemical interactions frustrate resolution of the toxicity of specific AAP components. We propose further strategies based on targeted gene expression based on cell-type differences.
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Affiliation(s)
- Henry Jay Forman
- Leonard Davis School of Gerontology, The University of Southern California, Los Angeles, CA, United States; School of Natural Sciences, University of California, Merced, CA, United States.
| | - Caleb Ellicott Finch
- Leonard Davis School of Gerontology, The University of Southern California, Los Angeles, CA, United States; Dornsife College, The University of Southern California, Los Angeles, CA, United States
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14
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Ferrosenescence: The iron age of neurodegeneration? Mech Ageing Dev 2017; 174:63-75. [PMID: 29180225 DOI: 10.1016/j.mad.2017.11.012] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 11/13/2017] [Accepted: 11/15/2017] [Indexed: 12/15/2022]
Abstract
Aging has been associated with iron retention in many cell types, including the neurons, promoting neurodegeneration by ferroptosis. Excess intracellular iron accelerates aging by damaging the DNA and blocking genomic repair systems, a process we define as ferrosenescence. Novel neuroimaging and proteomic techniques have pinpointed indicators of both iron retention and ferrosenescence, allowing for their early correction, potentially bringing prevention of neurodegenerative disorders within reach. In this review, we take a closer look at the early markers of iron dyshomeostasis in neurodegenerative disorders, focusing on preventive strategies based on nutritional and microbiome manipulations.
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Liao L, Zheng B, Yi B, Liu C, Chen L, Zeng Z, Gao J. Annexin A2-modulated proliferation of pulmonary arterial smooth muscle cells depends on caveolae and caveolin-1 in hepatopulmonary syndrome. Exp Cell Res 2017; 359:266-274. [PMID: 28729092 DOI: 10.1016/j.yexcr.2017.07.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 07/14/2017] [Accepted: 07/15/2017] [Indexed: 11/25/2022]
Abstract
We have established that annexin A2 (ANXA2) is an important factor in the experimental hepatopulmonary syndrome (HPS) serum-induced proliferation of pulmonary arterial smooth muscle cells (PASMCs). However, the detailed mechanism remains unclear. ANXA2 translocated to the caveolin-enriched microdomains (caveolae) in PASMCs upon HPS serum stimulation. The disruption of caveolae by Methyl-β-cyclodextrin (MβCD) alleviated the caveolae recruitment of ANXA2 and the ANXA2-mediated activation of ERK1/2 and NF-κB, so that ANXA2-modulated PASMC proliferation was suppressed. The over-expression of Cav-1 resulted in the relocation of ANXA2 from caveolae and negatively regulated ERK1/2 and NF-κB activation, which inhibited the ANXA2-modulated PASMC proliferative behavior. These data indicate that caveolae function as a signaling platform for ANXA2-induced proliferative behavior and Cav-1 participates upstream of ANXA2 in the activation of ERK1/2 and NF-κB.
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Affiliation(s)
- Lin Liao
- Department of Anesthesia, People's Hospital of Qijiang District, Chongqing 401420, China
| | - Binwu Zheng
- Department of Anesthesia, People's Hospital of Rongchang County, Chongqing 402460, China
| | - Bin Yi
- Department of Anesthesia, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China
| | - Chang Liu
- Department of Anesthesia, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China
| | - Lin Chen
- Department of Anesthesia, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China
| | - Ziyang Zeng
- Department of Anesthesia, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China.
| | - Jing Gao
- Department of Anesthesia, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China.
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16
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Zhang H, Zhou L, Yuen J, Birkner N, Leppert V, O'Day PA, Forman HJ. Delayed Nrf2-regulated antioxidant gene induction in response to silica nanoparticles. Free Radic Biol Med 2017; 108:311-319. [PMID: 28389405 PMCID: PMC5480609 DOI: 10.1016/j.freeradbiomed.2017.04.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 03/29/2017] [Accepted: 04/01/2017] [Indexed: 12/14/2022]
Abstract
Silica nanoparticles with iron on their surface cause the production of oxidants and stimulate an inflammatory response in macrophages. Nuclear factor erythroid-derived 2 - like factor 2 (Nrf2) signaling and its regulated antioxidant genes play critical roles in maintaining redox homeostasis. In this study we investigated the regulation of four representative Nrf2-regulated antioxidant genes; i.e., glutamate cysteine ligase (GCL) catalytic subunit (GCLC), GCL modifier subunit (GCLM), heme oxygenase 1 (HO-1), and NAD(P)H:quinone oxidoreductase-1 (NQO-1), by iron-coated silica nanoparticles (SiO2-Fe) in human THP-1 macrophages. We found that the expression of these four antioxidant genes was modified by SiO2-Fe in a time-dependent manner. At 6h, their expression was unchanged except for GCLC, which was reduced compared with controls. At 18h, the expression of these antioxidant genes was significantly increased compared with controls. In contrast, the Nrf2 activator sulforaphane induced all antioxidant genes at as early as 3h. The nuclear translocation of Nrf2 occurred later than that for NF-κB p65 protein and the induction of proinflammatory cytokines (TNFα and IL-1β). NF-κB inhibitor SN50 prevented the reduction of GCLC at 6h and abolished the induction of antioxidant genes at 18h by SiO2-Fe, but did not affect the basal and sulforaphane-induced expression of antioxidant genes, suggesting that NF-κB signaling plays a key role in the induction of Nrf2-mediated genes in response to SiO2-Fe. Consistently, SN50 inhibited the nuclear translocation of Nrf2 caused by SiO2-Fe. In addition, Nrf2 silencing decreased the basal and SiO2-induced expression of the four reprehensive antioxidant genes. Taken together, these data indicated that SiO2-Fe induced a delayed response of Nrf2-regulated antioxidant genes, likely through NF-κB-Nrf2 interactions.
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Affiliation(s)
- Hongqiao Zhang
- Leonard Davies School of Gerontology, University of Southern California, Los Angeles, CA 90089, United States.
| | - Lulu Zhou
- Leonard Davies School of Gerontology, University of Southern California, Los Angeles, CA 90089, United States
| | - Jenay Yuen
- Leonard Davies School of Gerontology, University of Southern California, Los Angeles, CA 90089, United States
| | - Nancy Birkner
- School of Natural Sciences and Sierra Nevada Research Institute, University of California at Merced, Merced, CA 95343, United States
| | - Valerie Leppert
- School of Engineering, University of California at Merced, Merced, CA 95343, United States
| | - Peggy A O'Day
- School of Natural Sciences and Sierra Nevada Research Institute, University of California at Merced, Merced, CA 95343, United States
| | - Henry Jay Forman
- Leonard Davies School of Gerontology, University of Southern California, Los Angeles, CA 90089, United States
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17
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Premshekharan G, Nguyen K, Zhang H, Forman HJ, Leppert VJ. Low dose inflammatory potential of silica particles in human-derived THP-1 macrophage cell culture studies - Mechanism and effects of particle size and iron. Chem Biol Interact 2017; 272:160-171. [PMID: 28512001 DOI: 10.1016/j.cbi.2017.05.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 04/22/2017] [Accepted: 05/03/2017] [Indexed: 11/16/2022]
Abstract
Silica and iron are major constituents in ambient particulate matter, and iron is a common impurity in many engineered nanomaterials. The purpose of this work was to determine the pro-inflammatory and other biological effects and mechanism of particle size and iron presence under low dose, non-cytotoxic conditions that are likely to approximate actual exposure levels, in contrast with higher dose studies in which cytotoxicity occurs. Specifically, human-derived THP-1 macrophages were exposed to 1 μg/ml of pristine and iron-coated 50 nm and 2 μm engineered silica nanoparticles. Particles were first characterized for size, size distribution, surface area, iron concentration, phase and aggregation in cell culture media. Then, biological assays were conducted to determine a non-lethal dose used in subsequent experiments. Superoxide production, lipid peroxidation, and increased pro-inflammatory cytokine (TNF-α and IL-1β) mRNA expression were measured as a function of particle size and iron presence. Smaller particle size and the presence of iron increased superoxide production, lipid peroxidation, and the induction of pro-inflammatory cytokine mRNA expression. Separate addition of an iron-chelator, a scavenger of superoxide and hydrogen peroxide, and an inhibitor of phosphatidylcholine specific phospholipase C (PC-PLC), suppressed the increase in cytokine mRNA expression. Furthermore, free iron itself showed none of the aforementioned effects. The results highlight the importance of particle size and iron in lung inflammation for both natural and engineered nanomaterials, under low dose, non-toxic conditions, and support the role of an oxidant, lipid peroxidation and PC-PLC dependent inflammatory mechanism.
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Affiliation(s)
- Gayatri Premshekharan
- School of Engineering, University of California, 5200 N. Lake Rd., Merced, CA 95343, United States
| | - Kennedy Nguyen
- School of Engineering, University of California, 5200 N. Lake Rd., Merced, CA 95343, United States
| | - Hongqiao Zhang
- School of Natural Sciences, University of California, 5200 N. Lake Rd., Merced, CA 95343, United States; Davis School of Gerontology, University of Southern California, 3715 McClintock Ave, Los Angeles, CA 90089, United States
| | - Henry Jay Forman
- School of Natural Sciences, University of California, 5200 N. Lake Rd., Merced, CA 95343, United States; Davis School of Gerontology, University of Southern California, 3715 McClintock Ave, Los Angeles, CA 90089, United States
| | - Valerie Jean Leppert
- School of Engineering, University of California, 5200 N. Lake Rd., Merced, CA 95343, United States.
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18
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Dos Anjos DO, Sobral Alves ES, Gonçalves VT, Fontes SS, Nogueira ML, Suarez-Fontes AM, Neves da Costa JB, Rios-Santos F, Vannier-Santos MA. Effects of a novel β-lapachone derivative on Trypanosoma cruzi: Parasite death involving apoptosis, autophagy and necrosis. Int J Parasitol Drugs Drug Resist 2016; 6:207-219. [PMID: 27770751 PMCID: PMC5078628 DOI: 10.1016/j.ijpddr.2016.10.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 10/07/2016] [Accepted: 10/10/2016] [Indexed: 12/18/2022]
Abstract
Natural products comprise valuable sources for new antiparasitic drugs. Here we tested the effects of a novel β-lapachone derivative on Trypanosoma cruzi parasite survival and proliferation and used microscopy and cytometry techniques to approach the mechanism(s) underlying parasite death. The selectivity index determination indicate that the compound trypanocidal activity was over ten-fold more cytotoxic to epimastigotes than to macrophages or splenocytes. Scanning electron microscopy analysis revealed that the R72 β-lapachone derivative affected the T. cruzi morphology and surface topography. General plasma membrane waving and blebbing particularly on the cytostome region were observed in the R72-treated parasites. Transmission electron microscopy observations confirmed the surface damage at the cytostome opening vicinity. We also observed ultrastructural evidence of the autophagic mechanism termed macroautophagy. Some of the autophagosomes involved large portions of the parasite cytoplasm and their fusion/confluence may lead to necrotic parasite death. The remarkably enhanced frequency of autophagy triggering was confirmed by quantitating monodansylcadaverine labeling. Some cells displayed evidence of chromatin pycnosis and nuclear fragmentation were detected. This latter phenomenon was also indicated by DAPI staining of R72-treated cells. The apoptotis induction was suggested to take place in circa one-third of the parasites assessed by annexin V labeling measured by flow cytometry. TUNEL staining corroborated the apoptosis induction. Propidium iodide labeling indicate that at least 10% of the R72-treated parasites suffered necrosis within 24 h. The present data indicate that the β-lapachone derivative R72 selectively triggers T. cruzi cell death, involving both apoptosis and autophagy-induced necrosis.
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Affiliation(s)
- Danielle Oliveira Dos Anjos
- Lab. Biologia Parasitária, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz - FIOCRUZ, Brazil; Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz UESC, Brazil
| | | | | | - Sheila Suarez Fontes
- Lab. Biologia Parasitária, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz - FIOCRUZ, Brazil
| | - Mateus Lima Nogueira
- Lab. Biologia Parasitária, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz - FIOCRUZ, Brazil
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Forman HJ. Redox signaling: An evolution from free radicals to aging. Free Radic Biol Med 2016; 97:398-407. [PMID: 27393004 PMCID: PMC4996735 DOI: 10.1016/j.freeradbiomed.2016.07.003] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 06/30/2016] [Accepted: 07/04/2016] [Indexed: 12/11/2022]
Abstract
Redox biology has evolved from studies of the pathology that involves oxidants to an understanding of how oxidants participate in normal as well as aberrant signal transduction. Although the concept that signal transduction involved changes in the redox state dates from the 1930s, the modern history of redox biology began with the discovery of superoxide dismutase by McCord and Fridovich. The initial focus was on free radicals and damage of macromolecules, which remains an important topic. But, over time it was realized that hydroperoxides, especially H2O2 produced by NADPH oxidases, and electrophiles derived from lipid peroxidation or metabolism, played essential roles in physiologically relevant signaling. The mechanisms through which H2O2 and other electrophiles signal became an important area of study that provided insight into how these reactive molecules were involved in major signaling pathways and regulation of transcription factors. Thus, the field of redox signaling that is the overlap of signal transduction with redox biology was established. Alterations in redox signaling are observed in aging, but we also now know that redox signaling is essential in physiological homeostasis and that sustained deviation from redox homeostasis results in disease. This is a review of the history of redox biology from a personal perspective of nearly fifty years working in this field that hopefully provides some insights for the reader.
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Affiliation(s)
- Henry Jay Forman
- Leonard Davis School of Gerontology, University of Southern California, 3715 McClintock Avenue, Los Angeles, CA 90089, United States
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20
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Ursini F, Maiorino M, Forman HJ. Redox homeostasis: The Golden Mean of healthy living. Redox Biol 2016; 8:205-15. [PMID: 26820564 PMCID: PMC4732014 DOI: 10.1016/j.redox.2016.01.010] [Citation(s) in RCA: 256] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 01/15/2016] [Accepted: 01/18/2016] [Indexed: 12/20/2022] Open
Abstract
The notion that electrophiles serve as messengers in cell signaling is now widely accepted. Nonetheless, major issues restrain acceptance of redox homeostasis and redox signaling as components of maintenance of a normal physiological steady state. The first is that redox signaling requires sudden switching on of oxidant production and bypassing of antioxidant mechanisms rather than a continuous process that, like other signaling mechanisms, can be smoothly turned up or down. The second is the misperception that reactions in redox signaling involve “reactive oxygen species” rather than reaction of specific electrophiles with specific protein thiolates. The third is that hormesis provides protection against oxidants by increasing cellular defense or repair mechanisms rather than by specifically addressing the offset of redox homeostasis. Instead, we propose that both oxidant and antioxidant signaling are main features of redox homeostasis. As the redox shift is rapidly reversed by feedback reactions, homeostasis is maintained by continuous signaling for production and elimination of electrophiles and nucleophiles. Redox homeostasis, which is the maintenance of nucleophilic tone, accounts for a healthy physiological steady state. Electrophiles and nucleophiles are not intrinsically harmful or protective, and redox homeostasis is an essential feature of both the response to challenges and subsequent feedback. While the balance between oxidants and nucleophiles is preserved in redox homeostasis, oxidative stress provokes the establishment of a new radically altered redox steady state. The popular belief that scavenging free radicals by antioxidants has a beneficial effect is wishful thinking. We propose, instead, that continuous feedback preserves nucleophilic tone and that this is supported by redox active nutritional phytochemicals. These nonessential compounds, by activating Nrf2, mimic the effect of endogenously produced electrophiles (parahormesis). In summary, while hormesis, although globally protective, results in setting up of a new phenotype, parahormesis contributes to health by favoring maintenance of homeostasis. Redox homeostasis is the continuously challenged oxidative/nucleophilic balance. Rheostatic redox signaling enzymes maintain oxidative/nucleophilic homeostasis. Phytochemicals assist redox homeostasis through oxidative feedback (parahormesis). Adaptation and hormesis while protective establish a new phenotype and set point.
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Affiliation(s)
- Fulvio Ursini
- Department of Molecular Medicine, University of Padova, Viale G. Colombo 3, I-35121 Padova, Italy
| | - Matilde Maiorino
- Department of Molecular Medicine, University of Padova, Viale G. Colombo 3, I-35121 Padova, Italy
| | - Henry Jay Forman
- Andrus Gerontology Center of the Davis School of Gerontology, University of Southern, California, 3715 McClintock Ave, Los Angeles, CA 90089-0191, USA
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Liao CM, Wu BC, Cheng YH, You SH, Lin YJ, Hsieh NH. Ceramics manufacturing contributes to ambient silica air pollution and burden of lung disease. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:15067-15079. [PMID: 26002365 DOI: 10.1007/s11356-015-4701-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 05/12/2015] [Indexed: 06/04/2023]
Abstract
Inhalation of silica (SiO2) in occupational exposures can cause pulmonary fibrosis (silicosis), lung function deficits, pulmonary inflammation, and lung cancer. Current risk assessment models, however, cannot fully explain the magnitude of silica-induced pulmonary disease risk. The purpose of this study was to assess human health risk exposed to airborne silica dust in Taiwan ceramics manufacturing. We conducted measurements to characterize workplace-specific airborne silica dust in tile and commodity ceramic factories and used physiologically based alveolar exposure model to estimate exposure dose. We constructed dose-response models for describing relationships between exposure dose and inflammatory responses, by which health risks among workers can be assessed. We found that silica contents were 0.22-33.04 % with mean concentration ranges of 0.11-5.48 and 0.46-1763.30 μg m(-3), respectively, in commodity and tile ceramic factories. We showed that granulation workers in tile ceramic factory had the highest total SiO2 lung burden (∼1000 mg) with cumulative SiO2 lung burden of ∼4 × 10(4) mg-year. The threshold estimates with an effect on human lung inflammation and fibrosis are 407.31 ± 277.10 (mean ± sd) and 505.91 ± 231.69 mg, respectively. For granulation workers, long-term exposure to airborne silica dust for 30-45 years was likely to pose severe adverse health risks of inflammation and fibrosis. We provide integrated assessment algorithms required to implement the analyses and maintain resulting concentration of silica dust at safety threshold level in the hope that they will stimulate further analyses and interpretation. We suggest that decision-makers take action to implement platforms for effective risk management to prevent the related long-term occupational disease in ceramics manufacturing.
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Affiliation(s)
- Chung-Min Liao
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, 10617, Taiwan, Republic of China.
| | - Bo-Chun Wu
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, 10617, Taiwan, Republic of China
| | - Yi-Hsien Cheng
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, 10617, Taiwan, Republic of China
| | - Shu-Han You
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, 10617, Taiwan, Republic of China
- National Environmental Health Research Center, National Health Research Institutes, Miaoli County, 35053, Taiwan, Republic of China
| | - Yi-Jun Lin
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, 10617, Taiwan, Republic of China
| | - Nan-Hung Hsieh
- Institute of Labor, Occupational Safety and Health, Ministry of Labor, Executive Yuan, New Taipei City, 22143, Taiwan, Republic of China
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22
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Spickett C, Fedorova M, Hoffmann R, Forman H. An Introduction to Redox Balance and Lipid Oxidation. OXIDATIVE STRESS AND DISEASE 2015. [DOI: 10.1201/b18138-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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23
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Shimizu Y, Dobashi K, Nagase H, Ohta K, Sano T, Matsuzaki S, Ishii Y, Satoh T, Koka M, Yokoyama A, Ohkubo T, Ishii Y, Kamiya T. Co-localization of iron binding on silica with p62/sequestosome1 (SQSTM1) in lung granulomas of mice with acute silicosis. J Clin Biochem Nutr 2014; 56:74-83. [PMID: 25834305 PMCID: PMC4306660 DOI: 10.3164/jcbn.14-44] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 09/02/2014] [Indexed: 01/05/2023] Open
Abstract
The cellular mechanisms involved in the development of silicosis have not been fully elucidated. This study aimed to examine influence of silica-induced lung injury on autophagy. Suspensions of crystalline silica particles were administered transnasally to C57BL/6j mice. Immunohistochemical examination for Fas and p62 protein expression was performed using lung tissue specimens. Two-dimensional and quantitative analysis of silica deposits in the lungs were performed in situ using lung tissue sections by an in-air microparticle induced X-ray emission (in-air micro-PIXE) analysis system, which was based on irrradiation of specimens with a proton ion microbeam. Quantitative analysis showed a significant increase of iron levels on silica particles (assessed as the ratio of Fe relative to Si) on day 56 compared with day 7 (p<0.05). Fas and p62 were expressed by histiocytes in granulomas on day 7, and the expressions persisted for day 56. Fas- and p62-expressing histiocytes were co-localized in granulomas with silica particles that showed an increase of iron levels on silica particles in mouse lungs. Iron complexed with silica induces apoptosis, and may lead to dysregulations of autophagy in histiocytes of granulomas, and these mechanisms may contribute to granuloma development and progression in silicosis.
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Affiliation(s)
- Yasuo Shimizu
- Department of Pulmonary Medicine and Clinical Immunology, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu-machi, Tochigi 321-0293, Japan ; Department of Respiratory Medicine, Maebashi Red Cross Hospital, 3-21-36 Asahi-cho, Maebashi-shi, Tochigi 371-0014, Japan ; Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, 3-39-15 Showa-machi, Maebashi-shi, Gunma 371-8511, Japan
| | - Kunio Dobashi
- Gunma University School of Health Sciences, 3-39-22 Showa-machi, Maebashi-shi, Gunma 371-8514, Japan
| | - Hiroyuki Nagase
- Division of Respiratory Medicine and Allergology, Department of Medicine, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan
| | - Ken Ohta
- Department of Respiratory Diseases, National Hospital Organization Tokyo National Hospital, Tokyo, 3-1-1 Takeoka, Kiyose-shi, Tokyo 204-8585, Japan
| | - Takaaki Sano
- Department of Diagnostic Pathology, Gunma University Graduate School of Medicine, 3-39-15 Showa-machi, Maebashi-shi, Gunma 371-8511, Japan
| | - Shinichi Matsuzaki
- Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, 3-39-15 Showa-machi, Maebashi-shi, Gunma 371-8511, Japan
| | - Yoshiki Ishii
- Department of Pulmonary Medicine and Clinical Immunology, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu-machi, Tochigi 321-0293, Japan
| | - Takahiro Satoh
- Japan Atomic Energy Agency, Takasaki Advanced Radiation Research Institute, 1233 Watanuki-machi, Takasaki-shi, Gunma 370-1292, Japan
| | - Masashi Koka
- Japan Atomic Energy Agency, Takasaki Advanced Radiation Research Institute, 1233 Watanuki-machi, Takasaki-shi, Gunma 370-1292, Japan
| | - Akihito Yokoyama
- Japan Atomic Energy Agency, Takasaki Advanced Radiation Research Institute, 1233 Watanuki-machi, Takasaki-shi, Gunma 370-1292, Japan
| | - Takeru Ohkubo
- Japan Atomic Energy Agency, Takasaki Advanced Radiation Research Institute, 1233 Watanuki-machi, Takasaki-shi, Gunma 370-1292, Japan
| | - Yasuyuki Ishii
- Japan Atomic Energy Agency, Takasaki Advanced Radiation Research Institute, 1233 Watanuki-machi, Takasaki-shi, Gunma 370-1292, Japan
| | - Tomihiro Kamiya
- Japan Atomic Energy Agency, Takasaki Advanced Radiation Research Institute, 1233 Watanuki-machi, Takasaki-shi, Gunma 370-1292, Japan
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Zhang L, Hong Z, Chen X, Tan S, Lin Y, Wang Y, Sun S, Cai W, Lu Z. Iron metabolism in neuromyelitis optica patients. J Neurol Sci 2014; 347:214-8. [PMID: 25456458 DOI: 10.1016/j.jns.2014.09.051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 09/11/2014] [Accepted: 09/30/2014] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The aim of this study was to investigate whether there was any relationship between iron metabolism and clinical features of NMO patients. METHODS We measured serum iron, ferritin, and transferrin levels in 25 patients with NMO and 25 controls. RESULTS The patients with NMO had significantly decreased serum iron and increased serum ferritin (P=0.001 and 0.002, respectively), both of which were in normal ranges. The serum iron level of NMO patients was not correlated with disease duration, relapse number, or magnetic resonance imaging lesions. After multivariate linear regression analysis, the serum iron level was correlated with age (P=0.003) but not EDSS score. CONCLUSIONS The iron metabolism might reflect the chronic oxidative injury in NMO patients. It is still unclear whether iron metabolism is implicated in the pathogenesis of NMO.
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Affiliation(s)
- Lei Zhang
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No 600 Tianhe Road, Guangzhou City, China; Department of Neurology, The Fifth Affiliated Hospital of Sun Yat-sen University, No 52 Meihuadong Road, Zhuhai City, China
| | - Zhongsi Hong
- Department of Infection, The Fifth Affiliated Hospital of Sun Yat-sen University, No 52 Meihuadong Road, Zhuhai City, China
| | - Xiaoyu Chen
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No 600 Tianhe Road, Guangzhou City, China
| | - Sha Tan
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No 600 Tianhe Road, Guangzhou City, China
| | - Yinyao Lin
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No 600 Tianhe Road, Guangzhou City, China
| | - Yanqiang Wang
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No 600 Tianhe Road, Guangzhou City, China
| | - Shaoyang Sun
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No 600 Tianhe Road, Guangzhou City, China
| | - Wei Cai
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No 600 Tianhe Road, Guangzhou City, China
| | - Zhengqi Lu
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, No 600 Tianhe Road, Guangzhou City, China.
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25
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Spadaro F, Cecchetti S, Purificato C, Sabbatucci M, Podo F, Ramoni C, Gessani S, Fantuzzi L. Nuclear phosphoinositide-specific phospholipase C β1 controls cytoplasmic CCL2 mRNA levels in HIV-1 gp120-stimulated primary human macrophages. PLoS One 2013; 8:e59705. [PMID: 23555755 PMCID: PMC3610878 DOI: 10.1371/journal.pone.0059705] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 02/17/2013] [Indexed: 01/21/2023] Open
Abstract
HIV-1 envelope glycoprotein gp120 induces, independently of infection, the release of CCL2 from macrophages. In turn, this chemokine acts as an autocrine factor enhancing viral replication. In this study, we show for the first time that phosphoinositide-specific phospholipase C (PI-PLC) is required for the production of CCL2 triggered by gp120 in macrophages. Using a combination of confocal laser-scanner microscopy, pharmacologic inhibition, western blotting and fluorescence-activated cell sorter analysis, we demonstrate that gp120 interaction with CCR5 leads to nuclear localization of the PI-PLC β1 isozyme mediated by mitogen-activated protein kinase ERK-1/2. Notably, phosphatidylcholine-specific phospholipase C (PC-PLC), previously reported to be required for NF-kB-mediated CCL2 production induced by gp120 in macrophages, drives both ERK1/2 activation and PI-PLC β1 nuclear localization induced by gp120. PI-PLC β1 activation through CCR5 is also triggered by the natural chemokine ligand CCL4, but independently of ERK1/2. Finally, PI-PLC inhibition neither blocks gp120-mediated NF-kB activation nor overall accumulation of CCL2 mRNA, whereas it decreases CCL2 transcript level in the cytoplasm. These results identify nuclear PI-PLC β1 as a new intermediate in the gp120-triggered PC-PLC-driven signal transduction pathway leading to CCL2 secretion in macrophages. The finding that a concerted gp120-mediated signaling involving both PC- and PI-specific PLCs is required for the expression of CCL2 in macrophages suggests that this signal transduction pathway may also be relevant for the modulation of viral replication in these cells. Thus, this study may contribute to identify novel targets for therapeutic intervention in HIV-1 infection.
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Affiliation(s)
- Francesca Spadaro
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Serena Cecchetti
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy
| | - Cristina Purificato
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Michela Sabbatucci
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Franca Podo
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy
| | - Carlo Ramoni
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy
| | - Sandra Gessani
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Laura Fantuzzi
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
- * E-mail:
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26
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Silicon, a Possible Link between Environmental Exposure and Autoimmune Diseases: The Case of Rheumatoid Arthritis. ARTHRITIS 2012; 2012:604187. [PMID: 23119159 PMCID: PMC3483651 DOI: 10.1155/2012/604187] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 09/13/2012] [Indexed: 12/28/2022]
Abstract
Silicon is one of the most common chemicals on earth. Several compounds such as silica, asbestos, silicone or, nanoparticles are built from tetrahedral units with silicon as the central atom. Despite these, structural similarities, they have rarely been analyzed as a group. These compounds generate significant biological alterations that include immune hyperactivation, production of the reactive species of oxygen and tissue injury. These pathological processes may trigger autoimmune responses and lead to the development of rheumatoid arthritis. Populations at risk include those that constantly work in industrial process, mining, and agriculture as well as those that undergo silicone implants. Herein a review on the main features of these compounds and how they may induce autoimmune responses is presented.
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27
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Huang P, Liu D, Gan X, Zhang R, Gao W, Xia Z, Hei Z. Mast cells activation contribute to small intestinal ischemia reperfusion induced acute lung injury in rats. Injury 2012; 43:1250-6. [PMID: 22277108 DOI: 10.1016/j.injury.2011.12.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 12/21/2011] [Accepted: 12/26/2011] [Indexed: 02/02/2023]
Abstract
BACKGROUND Small intestinal ischemia-reperfusion (IIR) injury may lead to severe local and remote tissue injury, especially acute lung injury (ALI). Mast cell activation plays an important role in IIR injury. It is unknown whether IIR mediates lung injury via mast cell activation. METHODS Adult SD rats were randomized into sham operated group (S), sole IIR group (IIR) in which rats were subjected to 75 min of superior mesenteric artery occlusion followed by 4h reperfusion, or IIR being respectively treated with the mast cell stabilizer Cromolyn Sodium (IIR+CS group), with the tryptase antagonist Protamine (IIR+P group), with the histamine receptor antagonist Ketotifen (IIR+K group), or with the mast cell degranulator Compound 48/80 (IIR+CP group). The above agents were, respectively, administrated intravenously 5 min before reperfusion. At the end of experiment, lung tissue was obtained for histologic assessment and assays for protein expressions of tryptase and mast cell protease 7(MCP7). Pulmonary mast cell number and levels of histamine, TNF-α and IL-8 were quantified. RESULTS IIR resulted in lung injury evidenced as significant increases in lung histological scores (P<0.05 IIR vs. S), accompanied with concomitant increases of mast cell counts and elevations in TNF-α and IL-8 concentrations and reductions in histamine levels (all P<0.05 IIR vs. S). IIR also increased lung tissue tryptase and MCP7 protein expressions (all P<0.05, IIR vs. S). Cromolyn Sodium, Ketotifen and Protamine significantly reduced whilst Compound 48/80 aggravated IIR mediated ALI and the above biochemical changes (P<0.05). CONCLUSIONS Mast cells activation play a critical role in IIR mediated ALI.
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Affiliation(s)
- Pinjie Huang
- Department of Anesthesiology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510630, China
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28
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Pfau JC, Seib T, Overocker JJ, Roe J, Ferro AS. Functional expression of system x(c)- is upregulated by asbestos but not crystalline silica in murine macrophages. Inhal Toxicol 2012; 24:476-85. [PMID: 22697888 DOI: 10.3109/08958378.2012.689782] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
CONTEXT Inhalation of asbestos or silica is associated with chronic and progressive diseases, including fibrosis, cancer, and increased risk of systemic autoimmunity. Because there is a need for treatment options for these diseases, a better understanding of their mechanistic etiologies is essential. While oxidative stress in macrophages is an early consequence of these exposures, it may also serve as a signaling mechanism involved in downstream immune dysregulation. The system x(c)(-) exchange protein is induced by oxidative stress, and exchanges equimolor levels of extracellular cystine for intracellular glutamate. Cystine is subsequently reduced to cysteine, the rate-limiting precursor for glutathione synthesis. OBJECTIVE As the primary transporter responsible for cystine/glutamate exchange on macrophages, system x(c)- was hypothesized to be inducible in response to asbestos and silica, and to increase viability through protection from oxidative stress. RESULTS When challenged with amphibole asbestos, but not crystalline silica, RAW 264.7 macrophages increased expression of xCT and the rate of cystine/glutamate exchange in sodium-free conditions. This upregulation was prevented with N-acetylcysteine, implicating oxidative stress. Cystine protected the macrophages from asbestos-induced oxidative stress and cell death, supporting the hypothesis that imported cystine was used for synthesis of cellular antioxidants. System x(c)(-) inhibitors, glutamate and S-4-carboxyphenylglycine ((S)-4-CPG), significantly increased oxidative stress and cell death of asbestos-treated macrophages. CONCLUSION System x(c)(-) plays a critical role in survival of macrophages exposed to asbestos, but not silica. These data demonstrate a very early difference in the cellular response to these silicates that may have important downstream implications in the pathologic outcome of exposure.
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Affiliation(s)
- Jean C Pfau
- Department of Biological Sciences, Idaho State University, Pocatello, ID 83209, USA.
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Zhang H, Liu H, Davies KJ, Sioutas C, Finch CE, Morgan TE, Forman HJ. Nrf2-regulated phase II enzymes are induced by chronic ambient nanoparticle exposure in young mice with age-related impairments. Free Radic Biol Med 2012; 52:2038-46. [PMID: 22401859 PMCID: PMC3342863 DOI: 10.1016/j.freeradbiomed.2012.02.042] [Citation(s) in RCA: 122] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 01/30/2012] [Accepted: 02/25/2012] [Indexed: 01/05/2023]
Abstract
Many xenobiotic detoxifying (phase II) enzymes are induced by sublethal doses of environmental toxicants. However, these adaptive mechanisms have not been studied in response to vehicular-derived airborne nano-sized particulate matter (nPM). Because aging is associated with increased susceptibility to environmental toxicants, we also examined the expression of Nrf2-regulated phase II genes in middle-aged mice and their inducibility by chronic nPM. The nPM from vehicular traffic was collected in urban Los Angeles and reaerosolized for exposure of C57BL/6J male mice (3 and 18 months old) for 150 h over 10 weeks. Brain (cerebellum), liver, and lung were assayed by RT-PCR and/or Western blots for the expression of phase II enzymes, glutamate cysteine ligase (catalytic GCLC, and modifier GCLM subunits), NAD(P)H:quinone oxidoreductase 1 (NQO1), heme oxygenase 1 (HO-1), and relevant transcription factors, NF-E2-related factor 2 (Nrf2), c-Myc, Bach1. Chronic nPM exposure induced GCLC, GCLM, HO-1, NQO1 mRNA, and protein similarly in cerebellum, liver, and lung of young mice. Middle-aged mice had elevated basal levels, but showed impaired further induction by nPM. Similarly, Nrf2 increased with age and was induced by nPM in young but not old. c-Myc showed the same age and induction profile while the age increase in Bach1 was further induced by nPM. Chronic exposure to nanoparticles induced Nrf2-regulated detoxifying enzymes in brain (cerebellum), liver, and lung of young adult mice, indicating a systemic impact of nPM. In contrast, middle-aged mice did not respond above their elevated basal levels except for Bach1. The lack of induction of phase II enzymes in aging mice may be a model for the vulnerability of elderly to air pollution.
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Affiliation(s)
- Hongqiao Zhang
- Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089
| | - Honglei Liu
- Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089
| | - Kelvin J.A. Davies
- Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089
| | - Constantinos Sioutas
- Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089
| | - Caleb E. Finch
- Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089
| | - Todd E. Morgan
- Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089
| | - Henry Jay Forman
- Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089
- University of California at Merced, Merced, CA 95343
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