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An Intercellular Flow of Glutathione Regulated by Interleukin 6 Links Astrocytes and the Liver in the Pathophysiology of Amyotrophic Lateral Sclerosis. Antioxidants (Basel) 2021; 10:antiox10122007. [PMID: 34943110 PMCID: PMC8698416 DOI: 10.3390/antiox10122007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 12/20/2022] Open
Abstract
Oxidative stress has been proposed as a major mechanism of damage to motor neurons associated with the progression of amyotrophic lateral sclerosis (ALS). Astrocytes are the most numerous glial cells in the central nervous system and, under physiological conditions, protect neurons from oxidative damage. However, it is uncertain how their reactive phenotype may affect motor neurons during ALS progression. In two different ALS mouse models (SOD1G93A and FUS-R521C), we found that increased levels of proinflammatory interleukin 6 facilitate glutathione (GSH) release from the liver to blood circulation, which can reach the astrocytes and be channeled towards motor neurons as a mechanism of antioxidant protection. Nevertheless, although ALS progression is associated with an increase in GSH efflux from astrocytes, generation of reactive oxygen species also increases, suggesting that as the disease progresses, astrocyte-derived oxidative stress could be key to motor-neuron damage.
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Mesnil M, Defamie N, Naus C, Sarrouilhe D. Brain Disorders and Chemical Pollutants: A Gap Junction Link? Biomolecules 2020; 11:51. [PMID: 33396565 PMCID: PMC7824109 DOI: 10.3390/biom11010051] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 02/07/2023] Open
Abstract
The incidence of brain pathologies has increased during last decades. Better diagnosis (autism spectrum disorders) and longer life expectancy (Parkinson's disease, Alzheimer's disease) partly explain this increase, while emerging data suggest pollutant exposures as a possible but still underestimated cause of major brain disorders. Taking into account that the brain parenchyma is rich in gap junctions and that most pollutants inhibit their function; brain disorders might be the consequence of gap-junctional alterations due to long-term exposures to pollutants. In this article, this hypothesis is addressed through three complementary aspects: (1) the gap-junctional organization and connexin expression in brain parenchyma and their function; (2) the effect of major pollutants (pesticides, bisphenol A, phthalates, heavy metals, airborne particles, etc.) on gap-junctional and connexin functions; (3) a description of the major brain disorders categorized as neurodevelopmental (autism spectrum disorders, attention deficit hyperactivity disorders, epilepsy), neurobehavioral (migraines, major depressive disorders), neurodegenerative (Parkinson's and Alzheimer's diseases) and cancers (glioma), in which both connexin dysfunction and pollutant involvement have been described. Based on these different aspects, the possible involvement of pollutant-inhibited gap junctions in brain disorders is discussed for prenatal and postnatal exposures.
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Affiliation(s)
- Marc Mesnil
- Laboratoire STIM, ERL7003 CNRS-Université de Poitiers, 1 rue G. Bonnet–TSA 51 106, 86073 Poitiers, France; (M.M.); (N.D.)
| | - Norah Defamie
- Laboratoire STIM, ERL7003 CNRS-Université de Poitiers, 1 rue G. Bonnet–TSA 51 106, 86073 Poitiers, France; (M.M.); (N.D.)
| | - Christian Naus
- Faculty of Medicine, Department of Cellular & Physiological Sciences, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T1Z3, Canada;
| | - Denis Sarrouilhe
- Laboratoire de Physiologie Humaine, Faculté de Médecine et Pharmacie, 6 rue de La Milétrie, bât D1, TSA 51115, 86073 Poitiers, France
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Kayasandik CB, Ru W, Labate D. A multistep deep learning framework for the automated detection and segmentation of astrocytes in fluorescent images of brain tissue. Sci Rep 2020; 10:5137. [PMID: 32198485 PMCID: PMC7083864 DOI: 10.1038/s41598-020-61953-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 03/04/2020] [Indexed: 02/07/2023] Open
Abstract
While astrocytes have been traditionally described as passive supportive cells, studies during the last decade have shown they are active players in many aspects of CNS physiology and function both in normal and disease states. However, the precise mechanisms regulating astrocytes function and interactions within the CNS are still poorly understood. This knowledge gap is due in large part to the limitations of current image analysis tools that cannot process astrocyte images efficiently and to the lack of methods capable of quantifying their complex morphological characteristics. To provide an unbiased and accurate framework for the quantitative analysis of fluorescent images of astrocytes, we introduce a new automated image processing pipeline whose main novelties include an innovative module for cell detection based on multiscale directional filters and a segmentation routine that leverages deep learning and sparse representations to reduce the need of training data and improve performance. Extensive numerical tests show that our method performs very competitively with respect to state-of-the-art methods also in challenging images where astrocytes are clustered together. Our code is released open source and freely available to the scientific community.
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Affiliation(s)
| | - Wenjuan Ru
- Center for Neurodegeneration, Houston Methodist Research Institute, Houston, Texas, United States of America
| | - Demetrio Labate
- University of Houston, Department of Mathematics, Houston, Texas, United States of America.
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Pavlou MAS, Grandbarbe L, Buckley NJ, Niclou SP, Michelucci A. Transcriptional and epigenetic mechanisms underlying astrocyte identity. Prog Neurobiol 2018; 174:36-52. [PMID: 30599178 DOI: 10.1016/j.pneurobio.2018.12.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 11/20/2018] [Accepted: 12/28/2018] [Indexed: 12/14/2022]
Abstract
Astrocytes play a significant role in coordinating neural development and provide critical support for the function of the CNS. They possess important adaptation capacities that range from their transition towards reactive astrocytes to their ability to undergo reprogramming, thereby revealing their potential to retain latent features of neural progenitor cells. We propose that the mechanisms underlying reactive astrogliosis or astrocyte reprogramming provide an opportunity for initiating neuronal regeneration, a process that is notably reduced in the mammalian nervous system throughout evolution. Conversely, this plasticity may also affect normal astrocytic functions resulting in pathologies ranging from neurodevelopmental disorders to neurodegenerative diseases and brain tumors. We postulate that epigenetic mechanisms linking extrinsic cues and intrinsic transcriptional programs are key factors to maintain astrocyte identity and function, and critically, to control the balance of regenerative and degenerative activity. Here, we will review the main evidences supporting this concept. We propose that unravelling the epigenetic and transcriptional mechanisms underlying the acquisition of astrocyte identity and plasticity, as well as understanding how these processes are modulated by the local microenvironment under specific threatening or pathological conditions, may pave the way to new therapeutic avenues for several neurological disorders including neurodegenerative diseases and brain tumors of astrocytic lineage.
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Affiliation(s)
- Maria Angeliki S Pavlou
- Life Sciences Research Unit, University of Luxembourg, Esch-sur-Alzette, Luxembourg; NORLUX Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - Luc Grandbarbe
- Life Sciences Research Unit, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Noel J Buckley
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, United Kingdom
| | - Simone P Niclou
- NORLUX Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, Luxembourg, Luxembourg; KG Jebsen Brain Tumour Research Center, Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Alessandro Michelucci
- NORLUX Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, Luxembourg, Luxembourg; Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-Belval, Luxembourg.
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5
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Chiu CD, Yao NW, Guo JH, Shen CC, Lee HT, Chiu YP, Ji HR, Chen X, Chen CC, Chang C. Inhibition of astrocytic activity alleviates sequela in acute stages of intracerebral hemorrhage. Oncotarget 2017; 8:94850-94861. [PMID: 29212271 PMCID: PMC5706917 DOI: 10.18632/oncotarget.22022] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 09/22/2017] [Indexed: 12/27/2022] Open
Abstract
Neurological deterioration of intracerebral hemorrhage (ICH) mostly occurs within the first 24 hours. Together with the microglia/macrophages (MMΦ), astrocytes are important cell population responsible for many brain injuries but rarely being highlighted in acute stage of ICH. In present study, we induced rats ICH either by collagenase or autologous blood injection. Experimental groups were classified as vehicle or Ethyl-1-(4-(2,3,3-trichloroacrylamide)phenyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylate (Pyr3) treatment group (n = 9, each group). MRI assessments after ICH were used to evaluate the hematoma progression and blood-brain barrier (BBB) integrity. The glia cells accumulations were examined by GFAP and Iba1 immunohistochemistry, respectively. Abundant astrocytes but few MMΦ were observed in hyperacute and acute ICH. Upon suppression of astrocyte activity, ICH rats exhibited decreased size of hematoma expansion, less BBB destruction, reduced astrocyte accumulation in perihematomal regions, postponed course of hemoresolution and gain better outcomes. These finding provide evidence that activated astrocytes are crucial cell populations in hyperacute and acute ICH, and their modulation may offer opportunities for novel therapy and patient management.
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Affiliation(s)
- Cheng-Di Chiu
- School of Medicine, China Medical University, Taichung, Taiwan.,Graduate Institute of Biomedical Science, China Medical University, Taichung, Taiwan.,Department of Neurosurgery, China Medical University Hospital, Taichung, Taiwan.,Stroke Center, China Medical University Hospital, Taichung, Taiwan
| | - Nai-Wei Yao
- School of Medicine, China Medical University, Taichung, Taiwan.,Institute of Biomedical Sciences, Academic Sinica, Taipei, Taiwan.,Stroke Center, China Medical University Hospital, Taichung, Taiwan
| | - Jeng-Hung Guo
- Department of Neurosurgery, China Medical University Hospital, Taichung, Taiwan
| | - Chiung-Chyi Shen
- Department of Minimally Invasive Skull Base Neurosurgery, Neurological Institute, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Hsu-Tung Lee
- Department of Neurosurgical Oncology, Neurological Institute, Taichung Veterans General Hospital, Taichung, Taiwan
| | - You-Pen Chiu
- School of Medicine, China Medical University, Taichung, Taiwan.,Stroke Center, China Medical University Hospital, Taichung, Taiwan
| | - Hui-Ru Ji
- Graduate Institute of Biomedical Science, China Medical University, Taichung, Taiwan.,Stroke Center, China Medical University Hospital, Taichung, Taiwan
| | - Xianxiu Chen
- School of Medicine, China Medical University, Taichung, Taiwan.,Department of Neurosurgery, China Medical University Hospital, Taichung, Taiwan.,Stroke Center, China Medical University Hospital, Taichung, Taiwan
| | - Chun-Chung Chen
- School of Medicine, China Medical University, Taichung, Taiwan.,Department of Neurosurgery, China Medical University Hospital, Taichung, Taiwan.,Stroke Center, China Medical University Hospital, Taichung, Taiwan
| | - Chen Chang
- Institute of Biomedical Sciences, Academic Sinica, Taipei, Taiwan
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Temporal Profiling of Astrocyte Precursors Reveals Parallel Roles for Asef during Development and after Injury. J Neurosci 2017; 36:11904-11917. [PMID: 27881777 DOI: 10.1523/jneurosci.1658-16.2016] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 09/12/2016] [Accepted: 09/18/2016] [Indexed: 12/21/2022] Open
Abstract
Lineage development is a stepwise process, governed by stage-specific regulatory factors and associated markers. Astrocytes are one of the principle cell types in the CNS and the stages associated with their development remain very poorly defined. To identify these stages, we performed gene-expression profiling on astrocyte precursor populations in the spinal cord, identifying distinct patterns of gene induction during their development that are strongly correlated with human astrocytes. Validation studies identified a new cohort of astrocyte-associated genes during development and demonstrated their expression in reactive astrocytes in human white matter injury (WMI). Functional studies on one of these genes revealed that mice lacking Asef exhibited impaired astrocyte differentiation during development and repair after WMI, coupled with compromised blood-brain barrier integrity in the adult CNS. These studies have identified distinct stages of astrocyte lineage development associated with human WMI and, together with our functional analysis of Asef, highlight the parallels between astrocyte development and their reactive counterparts associated with injury. SIGNIFICANCE STATEMENT Astrocytes play a central role in CNS function and associated diseases. Yet the mechanisms that control their development remain poorly defined. Using the developing mouse spinal cord as a model system, we identify molecular changes that occur in developing astrocytes. These molecular signatures are strongly correlated with human astrocyte expression profiles and validation in mouse spinal cord identifies a host of new genes associated with the astrocyte lineage. These genes are present in reactive astrocytes in human white matter injury, and functional studies reveal that one of these genes, Asef, contributes to reactive astrocyte responses after injury. These studies identify distinct stages of astrocyte lineage development and highlight the parallels between astrocyte development and their reactive counterparts associated with injury.
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Roshan MHK, Tambo A, Pace NP. Potential Role of Caffeine in the Treatment of Parkinson's Disease. Open Neurol J 2016; 10:42-58. [PMID: 27563362 PMCID: PMC4962431 DOI: 10.2174/1874205x01610010042] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 04/30/2016] [Accepted: 05/02/2016] [Indexed: 12/20/2022] Open
Abstract
Parkinson’s disease [PD] is the second most common neurodegenerative disorder after Alzheimer’s disease, affecting 1% of the population over the age of 55. The underlying neuropathology seen in PD is characterised by progressive loss of dopaminergic neurons in the substantia nigra pars compacta with the presence of Lewy bodies. The Lewy bodies are composed of aggregates of α-synuclein. The motor manifestations of PD include a resting tremor, bradykinesia, and muscle rigidity. Currently there is no cure for PD and motor symptoms are treated with a number of drugs including levodopa [L-dopa]. These drugs do not delay progression of the disease and often provide only temporary relief. Their use is often accompanied by severe adverse effects. Emerging evidence from both in vivo and in vitro studies suggests that caffeine may reduce parkinsonian motor symptoms by antagonising the adenosine A2A receptor, which is predominately expressed in the basal ganglia. It is hypothesised that caffeine may increase the excitatory activity in local areas by inhibiting the astrocytic inflammatory processes but evidence remains inconclusive. In addition, the co-administration of caffeine with currently available PD drugs helps to reduce drug tolerance, suggesting that caffeine may be used as an adjuvant in treating PD. In conclusion, caffeine may have a wide range of therapeutic effects which are yet to be explored, and therefore warrants further investigation in randomized clinical trials.
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Affiliation(s)
- Mohsin H K Roshan
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta- Msida, Malta
| | - Amos Tambo
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta- Msida, Malta
| | - Nikolai P Pace
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta- Msida, Malta
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Molofsky AV, Deneen B. Astrocyte development: A Guide for the Perplexed. Glia 2015; 63:1320-9. [PMID: 25963996 DOI: 10.1002/glia.22836] [Citation(s) in RCA: 201] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 03/26/2015] [Indexed: 01/09/2023]
Abstract
Astrocytes are the predominant cell type in the brain and perform key functions vital to CNS physiology, including blood brain barrier formation and maintenance, synaptogenesis, neurotransmission, and metabolic regulation. To fully understand the contributions of astrocytes to brain function, it will be important to bridge the existing gap between development and physiology. In this review, we provide an overview of Astrocyte development, including recent insights into molecular mechanisms of astrocyte specification, regional patterning and proliferation. This developmental perspective is complemented with recent findings that describe the functional maturation of astrocytes and their prospective diversity. Future progress in understanding Astrocyte development will depend on the development of astrocyte- stage specific markers and tools for manipulating astrocytes without affecting neuron production. Ultimately, a mechanistic approach to Astrocyte development will be crucial to developing new treatments for the many neurodevelopmental, neurodegenerative, neuroimmune, and neoplastic diseases involving astrocyte dysfunction.
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Affiliation(s)
- Anna Victoria Molofsky
- Department of Psychiatry, University of California-San Francisco, San Francisco, California
| | - Benjamin Deneen
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas
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9
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Abstract
Vertebrate myelination is an evolutionary advancement essential for motor, sensory, and higher-order cognitive function. CNS myelin, a multilamellar differentiation of the oligodendrocyte plasma membrane, ensheaths axons to facilitate electrical conduction. Myelination is one of the most pivotal cell-cell interactions for normal brain development, involving extensive information exchange between differentiating oligodendrocytes and axons. The molecular mechanisms of myelination are discussed, along with new perspectives on oligodendrocyte plasticity and myelin remodeling of the developing and adult CNS.
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10
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Uptake, Metabolic Effects and Toxicity of Arsenate and Arsenite in Astrocytes. Neurochem Res 2015; 41:465-75. [DOI: 10.1007/s11064-015-1570-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 03/30/2015] [Accepted: 04/01/2015] [Indexed: 12/17/2022]
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11
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Ahlberg S, Antonopulos A, Diendorf J, Dringen R, Epple M, Flöck R, Goedecke W, Graf C, Haberl N, Helmlinger J, Herzog F, Heuer F, Hirn S, Johannes C, Kittler S, Köller M, Korn K, Kreyling WG, Krombach F, Lademann J, Loza K, Luther EM, Malissek M, Meinke MC, Nordmeyer D, Pailliart A, Raabe J, Rancan F, Rothen-Rutishauser B, Rühl E, Schleh C, Seibel A, Sengstock C, Treuel L, Vogt A, Weber K, Zellner R. PVP-coated, negatively charged silver nanoparticles: A multi-center study of their physicochemical characteristics, cell culture and in vivo experiments. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2014; 5:1944-65. [PMID: 25383306 PMCID: PMC4222445 DOI: 10.3762/bjnano.5.205] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 10/07/2014] [Indexed: 04/14/2023]
Abstract
PVP-capped silver nanoparticles with a diameter of the metallic core of 70 nm, a hydrodynamic diameter of 120 nm and a zeta potential of -20 mV were prepared and investigated with regard to their biological activity. This review summarizes the physicochemical properties (dissolution, protein adsorption, dispersability) of these nanoparticles and the cellular consequences of the exposure of a broad range of biological test systems to this defined type of silver nanoparticles. Silver nanoparticles dissolve in water in the presence of oxygen. In addition, in biological media (i.e., in the presence of proteins) the surface of silver nanoparticles is rapidly coated by a protein corona that influences their physicochemical and biological properties including cellular uptake. Silver nanoparticles are taken up by cell-type specific endocytosis pathways as demonstrated for hMSC, primary T-cells, primary monocytes, and astrocytes. A visualization of particles inside cells is possible by X-ray microscopy, fluorescence microscopy, and combined FIB/SEM analysis. By staining organelles, their localization inside the cell can be additionally determined. While primary brain astrocytes are shown to be fairly tolerant toward silver nanoparticles, silver nanoparticles induce the formation of DNA double-strand-breaks (DSB) and lead to chromosomal aberrations and sister-chromatid exchanges in Chinese hamster fibroblast cell lines (CHO9, K1, V79B). An exposure of rats to silver nanoparticles in vivo induced a moderate pulmonary toxicity, however, only at rather high concentrations. The same was found in precision-cut lung slices of rats in which silver nanoparticles remained mainly at the tissue surface. In a human 3D triple-cell culture model consisting of three cell types (alveolar epithelial cells, macrophages, and dendritic cells), adverse effects were also only found at high silver concentrations. The silver ions that are released from silver nanoparticles may be harmful to skin with disrupted barrier (e.g., wounds) and induce oxidative stress in skin cells (HaCaT). In conclusion, the data obtained on the effects of this well-defined type of silver nanoparticles on various biological systems clearly demonstrate that cell-type specific properties as well as experimental conditions determine the biocompatibility of and the cellular responses to an exposure with silver nanoparticles.
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