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Brawek B, Liang Y, Savitska D, Li K, Fomin-Thunemann N, Kovalchuk Y, Zirdum E, Jakobsson J, Garaschuk O. A new approach for ratiometric in vivo calcium imaging of microglia. Sci Rep 2017; 7:6030. [PMID: 28729628 PMCID: PMC5519759 DOI: 10.1038/s41598-017-05952-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 06/07/2017] [Indexed: 11/09/2022] Open
Abstract
Microglia, resident immune cells of the brain, react to the presence of pathogens/danger signals with a large repertoire of functional responses including morphological changes, proliferation, chemotaxis, production/release of cytokines, and phagocytosis. In vitro studies suggest that many of these effector functions are Ca2+-dependent, but our knowledge about in vivo Ca2+ signalling in microglia is rudimentary. This is mostly due to technical reasons, as microglia largely resisted all attempts of in vivo labelling with Ca2+ indicators. Here, we introduce a novel approach, utilizing a microglia-specific microRNA-9-regulated viral vector, enabling the expression of a genetically-encoded ratiometric Ca2+ sensor Twitch-2B in microglia. The Twitch-2B-assisted in vivo imaging enables recording of spontaneous and evoked microglial Ca2+ signals and allows for the first time to monitor the steady state intracellular Ca2+ levels in microglia. Intact in vivo microglia show very homogenous and low steady state intracellular Ca2+ levels. However, the levels increase significantly after acute slice preparation and cell culturing along with an increase in the expression of activation markers CD68 and IL-1β. These data identify the steady state intracellular Ca2+ level as a versatile microglial activation marker, which is highly sensitive to the cell's environment.
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Affiliation(s)
- Bianca Brawek
- Institute of Physiology II, University of Tübingen, 72074, Tübingen, Germany
| | - Yajie Liang
- Institute of Physiology II, University of Tübingen, 72074, Tübingen, Germany
| | - Daria Savitska
- Institute of Physiology II, University of Tübingen, 72074, Tübingen, Germany
| | - Kaizhen Li
- Institute of Physiology II, University of Tübingen, 72074, Tübingen, Germany
| | | | - Yury Kovalchuk
- Institute of Physiology II, University of Tübingen, 72074, Tübingen, Germany
| | - Elizabeta Zirdum
- Institute of Physiology II, University of Tübingen, 72074, Tübingen, Germany
| | - Johan Jakobsson
- Laboratory of Molecular Neurogenetics, Department of Experimental Medical Science, Wallenberg Neuroscience Center and Lund Stem Cell Center, Lund University, Lund, 221 84, Sweden
| | - Olga Garaschuk
- Institute of Physiology II, University of Tübingen, 72074, Tübingen, Germany.
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102
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Turner RC, Naser ZJ, Lucke-Wold BP, Logsdon AF, Vangilder RL, Matsumoto RR, Huber JD, Rosen CL. Single low-dose lipopolysaccharide preconditioning: neuroprotective against axonal injury and modulates glial cells. NEUROIMMUNOLOGY AND NEUROINFLAMMATION 2017; 4:6-15. [PMID: 28164149 PMCID: PMC5289820 DOI: 10.20517/2347-8659.2016.40] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Aim Over 7 million traumatic brain injuries (TBI) are reported each year in the United States. However, treatments and neuroprotection following TBI are limited because secondary injury cascades are poorly understood. Lipopolysaccharide (LPS) administration before controlled cortical impact can contribute to neuroprotection. However, the underlying mechanisms and whether LPS preconditioning confers neuroprotection against closed-head injuries remains unclear. Methods The authors hypothesized that preconditioning with a low dose of LPS (0.2 mg/kg) would regulate glial reactivity and protect against diffuse axonal injury induced by weight drop. LPS was administered 7 days prior to TBI. LPS administration reduced locomotion, which recovered completely by time of injury. Results LPS preconditioning significantly reduced the post-injury gliosis response near the corpus callosum, possibly by downregulating the oncostatin M receptor. These novel findings demonstrate a protective role of LPS preconditioning against diffuse axonal injury. LPS preconditioning successfully prevented neurodegeneration near the corpus callosum, as measured by fluorojade B. Conclusion Further work is required to elucidate whether LPS preconditioning confers long-term protection against behavioral deficits and to elucidate the biochemical mechanisms responsible for LPS-induced neuroprotective effects.
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Affiliation(s)
- Ryan C Turner
- Department of Neurosurgery, West Virginia University, School of Medicine, Morgantown, WV 26506, USA; Center for Neuroscience, West Virginia University, School of Medicine, Morgantown, WV 26506, USA
| | - Zachary J Naser
- Department of Neurosurgery, West Virginia University, School of Medicine, Morgantown, WV 26506, USA; Center for Neuroscience, West Virginia University, School of Medicine, Morgantown, WV 26506, USA
| | - Brandon P Lucke-Wold
- Department of Neurosurgery, West Virginia University, School of Medicine, Morgantown, WV 26506, USA; Center for Neuroscience, West Virginia University, School of Medicine, Morgantown, WV 26506, USA
| | - Aric F Logsdon
- Center for Neuroscience, West Virginia University, School of Medicine, Morgantown, WV 26506, USA; Department of Basic Pharmaceutical Sciences, West Virginia University, School of Pharmacy, Morgantown, WV 26506, USA
| | - Reyna L Vangilder
- Center for Neuroscience, West Virginia University, School of Medicine, Morgantown, WV 26506, USA; Center for Health Restoration, West Virginia University, School of Nursing, Morgantown, WV 26506, USA
| | - Rae R Matsumoto
- Center for Neuroscience, West Virginia University, School of Medicine, Morgantown, WV 26506, USA; Department of Basic Pharmaceutical Sciences, West Virginia University, School of Pharmacy, Morgantown, WV 26506, USA
| | - Jason D Huber
- Center for Neuroscience, West Virginia University, School of Medicine, Morgantown, WV 26506, USA; Department of Basic Pharmaceutical Sciences, West Virginia University, School of Pharmacy, Morgantown, WV 26506, USA
| | - Charles L Rosen
- Department of Neurosurgery, West Virginia University, School of Medicine, Morgantown, WV 26506, USA; Center for Neuroscience, West Virginia University, School of Medicine, Morgantown, WV 26506, USA
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103
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Oosterhof N, Holtman IR, Kuil LE, van der Linde HC, Boddeke EWGM, Eggen BJL, van Ham TJ. Identification of a conserved and acute neurodegeneration-specific microglial transcriptome in the zebrafish. Glia 2016; 65:138-149. [PMID: 27757989 PMCID: PMC5215681 DOI: 10.1002/glia.23083] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 09/21/2016] [Accepted: 09/28/2016] [Indexed: 12/29/2022]
Abstract
Microglia are brain resident macrophages important for brain development, connectivity, homeostasis and disease. However, it is still largely unclear how microglia functions and their identity are regulated at the molecular level. Although recent transcriptomic studies have identified genes specifically expressed in microglia, the function of most of these genes in microglia is still unknown. Here, we performed RNA sequencing on microglia acutely isolated from healthy and neurodegenerative zebrafish brains. We found that a large fraction of the mouse microglial signature is conserved in the zebrafish, corroborating the use of zebrafish to help understand microglial genetics in mammals in addition to studying basic microglia biology. Second, our transcriptome analysis of microglia following neuronal ablation suggested primarily a proliferative response of microglia, which we confirmed by immunohistochemistry and in vivo imaging. Together with the recent improvements in genome editing technology in zebrafish, these data offer opportunities to facilitate functional genetic research on microglia in vivo in the healthy as well as in the diseased brain. GLIA 2016;65:138–149
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Affiliation(s)
- Nynke Oosterhof
- Department of Clinical Genetics, Erasmus University Medical Center, Rotterdam, Wytemaweg 80, CN, 3015, The Netherlands
| | - Inge R Holtman
- Department of Neuroscience, Section Medical Physiology, University of Groningen, University Medical Center Groningen, A. Deusinglaan 1, 971 3, AV, Groningen, The Netherlands
| | - Laura E Kuil
- Department of Clinical Genetics, Erasmus University Medical Center, Rotterdam, Wytemaweg 80, CN, 3015, The Netherlands
| | - Herma C van der Linde
- Department of Clinical Genetics, Erasmus University Medical Center, Rotterdam, Wytemaweg 80, CN, 3015, The Netherlands
| | - Erik W G M Boddeke
- Department of Neuroscience, Section Medical Physiology, University of Groningen, University Medical Center Groningen, A. Deusinglaan 1, 971 3, AV, Groningen, The Netherlands
| | - Bart J L Eggen
- Department of Neuroscience, Section Medical Physiology, University of Groningen, University Medical Center Groningen, A. Deusinglaan 1, 971 3, AV, Groningen, The Netherlands
| | - Tjakko J van Ham
- Department of Clinical Genetics, Erasmus University Medical Center, Rotterdam, Wytemaweg 80, CN, 3015, The Netherlands
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Carson WF, Kunkel SL. Regulation of Cellular Immune Responses in Sepsis by Histone Modifications. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2016; 106:191-225. [PMID: 28057212 DOI: 10.1016/bs.apcsb.2016.08.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Severe sepsis, septic shock, and related inflammatory syndromes are driven by the aberrant expression of proinflammatory mediators by immune cells. During the acute phase of sepsis, overexpression of chemokines and cytokines drives physiological stress leading to organ failure and mortality. Following recovery from sepsis, the immune system exhibits profound immunosuppression, evidenced by an inability to produce the same proinflammatory mediators that are required for normal responses to infectious microorganisms. Gene expression in inflammatory responses is influenced by the transcriptional accessibility of the chromatin, with histone posttranslational modifications determining whether inflammatory gene loci are set to transcriptionally active, repressed, or poised states. Experimental evidence indicates that histone modifications play a central role in governing the cytokine storm of severe sepsis, and that aberrant chromatin modifications induced during the acute phase of sepsis may mediate chronic immunosuppression in sepsis survivors. This review will focus on the role of histone modifications in governing immune responses in severe sepsis, with an emphasis on specific leukocyte subsets and the histone modifications observed in these cells during chronic stages of sepsis. Additionally, the expression and function of chromatin-modifying enzymes (CMEs) will be discussed in the context of severe sepsis, as potential mediators of epigenetic regulation of gene expression in sepsis responses. In summary, this review will argue for the use of chromatin modifications and CME expression in leukocytes as potential biomarkers of immunosuppression in patients with severe sepsis.
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Affiliation(s)
- W F Carson
- University of Michigan Medical School, Ann Arbor, MI, United States.
| | - S L Kunkel
- University of Michigan Medical School, Ann Arbor, MI, United States
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105
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Matt SM, Lawson MA, Johnson RW. Aging and peripheral lipopolysaccharide can modulate epigenetic regulators and decrease IL-1β promoter DNA methylation in microglia. Neurobiol Aging 2016; 47:1-9. [PMID: 27500965 DOI: 10.1016/j.neurobiolaging.2016.07.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 07/01/2016] [Accepted: 07/07/2016] [Indexed: 12/23/2022]
Abstract
In aged mice, peripheral stimulation of the innate immune system with lipopolysaccharide (LPS) causes exaggerated neuroinflammation and prolonged sickness behavior due in part to microglial dysfunction. Epigenetic changes to DNA may play a role in microglial dysfunction; therefore, we sought to determine whether aged microglia displayed DNA hypomethylation of the interleukin-1 beta (IL-1β) promoter and altered expression of epigenetic regulators. We further examined whether the demethylating agent 5-azacytidine induced IL-1β expression in BV2 and primary microglia similar to microglia from aged mice. Novel findings indicated that aged mice had decreased methylation of the IL-1β gene promoter in primary microglia basally or following systemic LPS that is associated with increased IL-1β mRNA, intracellular IL-1β production, as well as prolonged sickness behavior. Last, 5-azacytidine increased IL-1β gene expression and decreased DNA methylation of BV2 and primary microglial cells similar to microglia from aged mice. Taken together, these data indicate that DNA methylation promotes heightened microglial activation in the aged brain.
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Affiliation(s)
- Stephanie M Matt
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Marcus A Lawson
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Rodney W Johnson
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Integrative Immunology and Behavior Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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106
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Neurons and astroglia govern microglial endotoxin tolerance through macrophage colony-stimulating factor receptor-mediated ERK1/2 signals. Brain Behav Immun 2016; 55:260-272. [PMID: 27132056 PMCID: PMC4899166 DOI: 10.1016/j.bbi.2016.04.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 04/20/2016] [Accepted: 04/26/2016] [Indexed: 11/20/2022] Open
Abstract
Endotoxin tolerance (ET) is a reduced responsiveness of innate immune cells like macrophages/monocytes to an endotoxin challenge following a previous encounter with the endotoxin. Although ET in peripheral systems has been well studied, little is known about ET in the brain. The present study showed that brain immune cells, microglia, being different from peripheral macrophages, displayed non-cell autonomous mechanisms in ET formation. Specifically, neurons and astroglia were indispensable for microglial ET. Macrophage colony-stimulating factor (M-CSF) secreted from these non-immune cells was essential for governing microglial ET. Neutralization of M-CSF deprived the neuron-glia conditioned medium of its ability to enable microglia to form ET when microglia encountered two lipopolysaccharide (LPS) treatments. Recombinant M-CSF protein rendered enriched microglia refractory to the second LPS challenge leading to microglial ET. Activation of microglial M-CSF receptor (M-CSFR; also known as CSF1R) and the downstream ERK1/2 signals was responsible for M-CSF-mediated microglial ET. Endotoxin-tolerant microglia in neuron-glia cultures displayed M2-like polarized phenotypes, as shown by upregulation of M2 marker Arg-1, elevated production of anti-inflammatory cytokine interleukin 10, and decreased secretion of pro-inflammatory mediators (tumor necrosis factor α, nitric oxide, prostaglandin E2 and interleukin 1β). Endotoxin-tolerant microglia protected neurons against LPS-elicited inflammatory insults, as shown by reduced neuronal damages in LPS pre-treatment group compared with the group without LPS pre-treatment. Moreover, while neurons and astroglia became injured during chronic neuroinflammation, microglia failed to form ET. Thus, this study identified a distinct non-cell autonomous mechanism of microglial ET. Interactions of M-CSF secreted by neurons and astroglia with microglial M-CSFR programed microglial ET. Loss of microglial ET could be an important pathogenetic mechanism of inflammation-associated neuronal damages.
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107
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Abstract
PURPOSE OF REVIEW The activation of inflammatory response is dependent upon genetic factors and epigenetic control mechanisms. This overview will highlight recent advances in the understanding of epigenetic dynamics during cellular inflammation. RECENT FINDINGS There is a growing body of evidence indicating that alterations of the chromatin state associate with an increased risk of chronic disease development and inflammation. Epigenetic alterations respond rapidly to environmental changes and have a profound effect on gene regulatory cross-wirings and transcriptional regulation. SUMMARY Systematic dissection of the mechanisms underlying epigenetic effects during inflammatory response is a critical step toward elucidation of the cell's molecular processes and holds potential for the development of novel therapies for the treatment of chronic diseases.
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Affiliation(s)
- Dashzeveg Bayarsaihan
- Institute for System Genomics and Center for Regenerative Medicine and Skeletal Development, University of Connecticut Health Center, Farmington, Connecticut, USA
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108
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Ajmone-Cat MA, D'Urso MC, di Blasio G, Brignone MS, De Simone R, Minghetti L. Glycogen synthase kinase 3 is part of the molecular machinery regulating the adaptive response to LPS stimulation in microglial cells. Brain Behav Immun 2016; 55:225-235. [PMID: 26593276 DOI: 10.1016/j.bbi.2015.11.012] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/31/2015] [Accepted: 11/20/2015] [Indexed: 12/31/2022] Open
Abstract
Repeated stimulation of TLR4 signaling by lipopolysaccharide (LPS) in microglia induces a state of tolerance/sensitization consisting in the reprogramming of the expression of pro-inflammatory genes in favor of anti-inflammatory ones. The molecular mechanisms underlying this adaptive response are far to be elucidated. Glycogen synthase kinase 3 (GSK3) has emerged as crucial regulator of TLR signaling, mediating the balance between pro- and anti-inflammatory functions in both periphery and central nervous system. The present study extends this notion identifying GSK3 as part of the molecular machinery regulating the LPS-adaptive response in microglial cells, by using primary microglial cultures and organotypic hippocampal slices (OHSCs). We found that lithium chloride (LiCl), a widely used GSK3 inhibitor and the mainstay treatment for bipolar disorder, reinforced the LPS adaptive response by enhancing both downregulation of pro-inflammatory genes (inducible nitric oxide synthase, interleukin 1β, interleukin 6, tumor necrosis factor α), and upregulation of genes typically associated to anti-inflammatory functions (interleukin 10 and MRC1). The effects of GSK3 inhibition were mimicked by Wnt3a, added exogenously, and reversed by Inhibitor of Wnt-Response-1-endo, a pharmacological disruptor of the canonical Wnt/β-catenin pathway, and GW9662, a selective peroxisome proliferator activated receptor γ antagonist, suggesting that these two pathways are involved in the regulation of LPS-tolerance/sensitization by GSK. Finally, LiCl treatment of OHSCs enhanced the protective functional consequences of the microglial adaptive response to LPS on oligodendrocyte maturation, as indicated by MBP mRNA upregulation. These results further indicate GSK3 as key component in the orchestration of neuroinflammation and target for neuroprotective strategies.
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Affiliation(s)
| | - Maria Cristina D'Urso
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy
| | - Giorgia di Blasio
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy
| | | | - Roberta De Simone
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy
| | - Luisa Minghetti
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy.
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Rios ECS, Soriano FG, Olah G, Gerö D, Szczesny B, Szabo C. Hydrogen sulfide modulates chromatin remodeling and inflammatory mediator production in response to endotoxin, but does not play a role in the development of endotoxin tolerance. JOURNAL OF INFLAMMATION-LONDON 2016; 13:10. [PMID: 27042162 PMCID: PMC4818437 DOI: 10.1186/s12950-016-0119-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 03/28/2016] [Indexed: 02/01/2023]
Abstract
Background Pretreatment with low doses of LPS (lipopolysaccharide, bacterial endotoxin) reduces the pro-inflammatory response to a subsequent higher LPS dose, a phenomenon known as endotoxin tolerance. Moreover, hydrogen sulfide (H2S), an endogenous gaseous mediator (gasotransmitter) can exert anti-inflammatory effects. Here we investigated the potential role of H2S in the development of LPS tolerance. THP1 differentiated macrophages were pretreated with the H2S donor NaHS (1 mM) or the H2S biosynthesis inhibitor aminooxyacetic acid (AOAA, 1 mM). Methods To induce tolerance, cells were treated with a low concentration of LPS (0.5 μg/ml) for 4 or 24 h, and then treated with a high concentration of LPS (1 μg/ml) for 4 h or 24 h. In in vivo studies, male wild-type and CSE-/- mice were randomized to the following groups: Control (vehicle); Endotoxemic saline for 3 days before the induction of endotoxemia with 10 mg/kg LPS) mg/kg; Tolerant (LPS at 1 mg/kg for 3 days, followed LPS at 10 mg/kg). Animals were sacrificed after 4 or 12 h; plasma IL-6 and TNF-α levels were measured. Changes in histone H3 and H4 acetylation were analyzed by Western blotting. Results LPS tolerance decreased pro-inflammatory cytokine production. AOAA did not affect the effect of tolerance on reducing cytokine production. Treatment of the cells with the H2S donor reduced cytokine production. Induction of the tolerance increased the acetylation of H3; AOAA reduced histone acetylation. H2S donation increased histone acetylation. Tolerance did not affect the responses to H2S with respect to histone acetylation. Conclusions In conclusion, both LPS tolerance and H2S donation decrease LPS-induced cytokine production in vitro and modulate histone acetylation. However, endogenous, CSE-derived H2S does not appear to play a significant role in the development of LPS tolerance.
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Affiliation(s)
- Ester C S Rios
- Department of Emergency Medicine, Universidade de São Paulo Medical School, São Paulo, Brazil
| | - Francisco G Soriano
- Department of Emergency Medicine, Universidade de São Paulo Medical School, São Paulo, Brazil
| | - Gabor Olah
- Department of Anesthesiology, University of Texas Medical Branch, 601 Harborside Drive, Building 21, Room 4.202D, Galveston, TX 77555-1102 USA
| | - Domokos Gerö
- Department of Anesthesiology, University of Texas Medical Branch, 601 Harborside Drive, Building 21, Room 4.202D, Galveston, TX 77555-1102 USA
| | - Bartosz Szczesny
- Department of Anesthesiology, University of Texas Medical Branch, 601 Harborside Drive, Building 21, Room 4.202D, Galveston, TX 77555-1102 USA
| | - Csaba Szabo
- Department of Anesthesiology, University of Texas Medical Branch, 601 Harborside Drive, Building 21, Room 4.202D, Galveston, TX 77555-1102 USA
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Chiariotti L, Coretti L, Pero R, Lembo F. Epigenetic Alterations Induced by Bacterial Lipopolysaccharides. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 879:91-105. [PMID: 26659265 DOI: 10.1007/978-3-319-24738-0_5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Lipopolysaccharide (LPS) is one of the principal bacterial products known to elicit inflammation. Cells of myeloid lineage such as monocytes and macrophages, but also epithelial cells give rise to an inflammatory response upon LPS stimulation. This phenomenon implies reprogramming of cell specific gene expression that can occur through different mechanisms including epigenetic modifications. Given their intrinsic nature, epigenetic modifications may be involved both in the acute response to LPS and in the establishment of a preconditioned genomic state (epigenomic memory) that may potentially influence the host response to further contacts with microorganisms. Information has accumulated during the last years aimed at elucidating the epigenetic mechanisms which underlie the cellular LPS response. These findings, summarized in this chapter, will hopefully be a good basis for a definition of the complete cascade of LPS-induced epigenetic events and their biological significance in different cell types.
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Affiliation(s)
- Lorenzo Chiariotti
- Department of Medicina Molecolare e Biotecnologie Mediche, University of Naples "Federico II", Naples, Italy. .,Istituto di Endocrinologia ed Oncologia Sperimentale IEOS, C.N.R., EPIGEN Laboratories, Naples, Italy.
| | - Lorena Coretti
- Department of Medicina Molecolare e Biotecnologie Mediche, University of Naples "Federico II", Naples, Italy.,Istituto di Endocrinologia ed Oncologia Sperimentale IEOS, C.N.R., EPIGEN Laboratories, Naples, Italy
| | - Raffaela Pero
- Department of Medicina Molecolare e Biotecnologie Mediche, University of Naples "Federico II", Naples, Italy
| | - Francesca Lembo
- Istituto di Endocrinologia ed Oncologia Sperimentale IEOS, C.N.R., EPIGEN Laboratories, Naples, Italy. .,Department of Pharmacy, University of Naples "Federico II", Naples, Italy.
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111
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Eslami M, Sayyah M, Soleimani M, Alizadeh L, Hadjighassem M. Lipopolysaccharide preconditioning prevents acceleration of kindling epileptogenesis induced by traumatic brain injury. J Neuroimmunol 2015; 289:143-51. [PMID: 26616884 DOI: 10.1016/j.jneuroim.2015.11.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/31/2015] [Accepted: 11/03/2015] [Indexed: 02/08/2023]
Abstract
10-20% of symptomatic epilepsies are post-traumatic. We examined effect of LPS preconditioning on epileptogenesis after controlled cortical impact (CCI). LPS (0.01, 0.1 and 0.5 mg/kg) was injected i.p. to rats 5 days before induction of CCI to parieto-temporal cortex. Kindling started 24h after CCI by i.p. injection of 30 mg/kg of pentylenetetrazole every other day until manifestation of 3 consecutive generalized seizures. CCI injury accelerated the rate of kindled seizures acquisition. LPS (0.1 and 0.5 mg/kg) prevented the acceleration of kindling. LPS preconditioning significantly decreased IL-1β and TNF-α over-expression and the number of damaged neurons in the hippocampus of traumatic rats.
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Affiliation(s)
- Mansoureh Eslami
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran; Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran; Department of Physiology and Pharmacology, Pasteur Institute of Iran, Tehran, Iran; Department of Basic Sciences, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Sayyah
- Department of Physiology and Pharmacology, Pasteur Institute of Iran, Tehran, Iran.
| | - Mansoureh Soleimani
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | | | - Mahmoudreza Hadjighassem
- Brain and Spinal cord injury Research Center, Neuroscience Institute, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran; Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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112
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Netea MG, Latz E, Mills KHG, O'Neill LAJ. Innate immune memory: a paradigm shift in understanding host defense. Nat Immunol 2015; 16:675-9. [DOI: 10.1038/ni.3178] [Citation(s) in RCA: 155] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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