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Zou K, Deng Q, Zhang H, Huang C. Glymphatic system: a gateway for neuroinflammation. Neural Regen Res 2024; 19:2661-2672. [PMID: 38595285 PMCID: PMC11168510 DOI: 10.4103/1673-5374.391312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/15/2023] [Accepted: 11/09/2023] [Indexed: 04/11/2024] Open
Abstract
The glymphatic system is a relatively recently identified fluid exchange and transport system in the brain. Accumulating evidence indicates that glymphatic function is impaired not only in central nervous system disorders but also in systemic diseases. Systemic diseases can trigger the inflammatory responses in the central nervous system, occasionally leading to sustained inflammation and functional disturbance of the central nervous system. This review summarizes the current knowledge on the association between glymphatic dysfunction and central nervous system inflammation. In addition, we discuss the hypothesis that disease conditions initially associated with peripheral inflammation overwhelm the performance of the glymphatic system, thereby triggering central nervous system dysfunction, chronic neuroinflammation, and neurodegeneration. Future research investigating the role of the glymphatic system in neuroinflammation may offer innovative therapeutic approaches for central nervous system disorders.
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Affiliation(s)
- Kailu Zou
- Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Qingwei Deng
- Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Hong Zhang
- Xiangya School of Medicine, Central South University, Changsha, Hunan Province, China
| | - Changsheng Huang
- Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
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2
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Sriram S, Carstens K, Dewing W, Fiacco TA. Astrocyte regulation of extracellular space parameters across the sleep-wake cycle. Front Cell Neurosci 2024; 18:1401698. [PMID: 38988660 PMCID: PMC11233815 DOI: 10.3389/fncel.2024.1401698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Accepted: 06/07/2024] [Indexed: 07/12/2024] Open
Abstract
Multiple subfields of neuroscience research are beginning to incorporate astrocytes into current frameworks of understanding overall brain physiology, neuronal circuitry, and disease etiology that underlie sleep and sleep-related disorders. Astrocytes have emerged as a dynamic regulator of neuronal activity through control of extracellular space (ECS) volume and composition, both of which can vary dramatically during different levels of sleep and arousal. Astrocytes are also an attractive target of sleep research due to their prominent role in the glymphatic system, a method by which toxic metabolites generated during wakefulness are cleared away. In this review we assess the literature surrounding glial influences on fluctuations in ECS volume and composition across the sleep-wake cycle. We also examine mechanisms of astrocyte volume regulation in glymphatic solute clearance and their role in sleep and wake states. Overall, findings highlight the importance of astrocytes in sleep and sleep research.
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Affiliation(s)
- Sandhya Sriram
- Interdepartmental Graduate Program in Neuroscience, University of California, Riverside, Riverside, CA, United States
- Department of Biochemistry and Molecular Biology, University of California, Riverside, Riverside, CA, United States
| | - Kaira Carstens
- Department of Biochemistry and Molecular Biology, University of California, Riverside, Riverside, CA, United States
| | - Wayne Dewing
- Undergraduate Major in Neuroscience, University of California, Riverside, Riverside, CA, United States
| | - Todd A Fiacco
- Interdepartmental Graduate Program in Neuroscience, University of California, Riverside, Riverside, CA, United States
- Department of Biochemistry and Molecular Biology, University of California, Riverside, Riverside, CA, United States
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3
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Zheng S, Zhao X, Huang J, Tian Q, Xu S, Bo R, Liu M, Li J. Eugenol alleviates Salmonella Typhimurium-infected cecal injury by modulating cecal flora and tight junctions accompanied by suppressing inflammation. Microb Pathog 2023; 179:106113. [PMID: 37062493 DOI: 10.1016/j.micpath.2023.106113] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 04/13/2023] [Indexed: 04/18/2023]
Abstract
BACKGROUND Salmonella enterica serovar Typhimurium (ST) mainly exists in poultry and poultry related products, which are common sources of human salmonellosis. So, ST is an important zoonotic pathogen that threatens public health and safety. Eugenol has been noted for its antibacterial and anti-inflammatory properties, and it is expected to develop into an antibacterial therapy in vivo. METHODS Herein, the effects of eugenol against ST infection in terms of intestinal flora, cecal tight junction, and cecal inflammation in broilers was evaluated in this study. RESULTS The results showed that oral eugenol pretreatment obviously relieved the histopathological changes and ultrastructural injury of cecum caused by ST infection. Further analysis found that eugenol lessened the number of ST in the cecum, restrained Proteobacteria and Ruminococcus, and kept the ratio of Firmicutes to Bacteroidetes (F/B), improved the relative abundance of Alistipes compared to the infection control. Moreover, eugenol sustained the expression of ZO-1, claudin-1, and occluding tight junction proteins, reduced the mRNA levels of myeloid differentiation factor 88 (MyD88), toll-like receptor-4 (TLR4) and inducible nitric oxide synthesis (iNOS), suppressed the phosphorylation of p65 and IκBα in the NF-κB signaling pathway, as well as the mRNA levels of TNF-α, IL-1β, IL-2, and IL-18 in the cecum tissue. CONCLUSION Taken together, eugenol could protect broilers against ST infection via maintaining intestinal flora, tight junctions involved in mucosal barrier function, then accordingly limiting the excessive inflammation, finally contributed to improving relative weight gains and survival rates of broilers.
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Affiliation(s)
- ShuMei Zheng
- School of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, PR China
| | - Xin Zhao
- School of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, PR China
| | - JunJie Huang
- School of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, PR China
| | - QiMing Tian
- School of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, PR China
| | - ShuYa Xu
- School of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, PR China
| | - RuoNan Bo
- School of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, PR China
| | - MingJiang Liu
- School of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, PR China
| | - JinGui Li
- School of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, PR China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu, 225009, PR China.
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Barabási B, Barna L, Santa-Maria AR, Harazin A, Molnár R, Kincses A, Vigh JP, Dukay B, Sántha M, Tóth ME, Walter FR, Deli MA, Hoyk Z. Role of interleukin-6 and interleukin-10 in morphological and functional changes of the blood-brain barrier in hypertriglyceridemia. Fluids Barriers CNS 2023; 20:15. [PMID: 36882782 PMCID: PMC9990353 DOI: 10.1186/s12987-023-00418-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 02/24/2023] [Indexed: 03/09/2023] Open
Abstract
BACKGROUND Hypertriglyceridemia is closely linked to atherosclerosis related inflammatory processes and blood-brain barrier (BBB) dysfunction. Using apolipoprotein B-100 (APOB-100) transgenic mice, an animal model of chronic hypertriglyceridemia, we analyzed BBB function and morphology in vitro and ex vivo. Our objective was to determine which BBB characteristics are produced mainly by interleukin (IL)-6, an atherosclerosis promoting cytokine, and whether these actions can be antagonized by IL-10, an anti-inflammatory cytokine. METHODS Brain endothelial and glial cell cultures and brain microvessels were isolated from wild type (WT) and APOB-100 transgenic mice and were treated with IL-6, IL-10 and their combination. First, IL-6 and IL-10 production was measured in WT and APOB-100 microvessels using qPCR. Then functional parameters of endothelial cell cultures were analyzed and immunocytochemistry for key BBB proteins was performed. RESULTS IL-6 mRNA levels were higher in brain microvessels than in brain parenchyma of APOB-100 transgenic mice. Transendothelial electric resistance and P-glycoprotein activity were lower, and paracellular permeability was higher in cultured APOB-100 brain endothelial cells. These features were sensitive to both IL-6 and IL-10 treatments. A decreased P-glycoprotein immunostaining was measured in transgenic endothelial cells under control conditions and in WT cells after treating them with IL-6. This effect was antagonized by IL-10. Changes in immunostaining for tight junction proteins were observed after IL-6 exposure, which were in part antagonized by IL-10. In glial cell cultures an increase in aquaporin-4 immunolabeling in the transgenic group and an increase in microglia cell density in WT glia cultures was detected after IL-6 treatment, which was antagonized by IL-10. In isolated brain microvessels a decrease in P-glycoprotein immunolabeled area fraction was measured in APOB-100 microvessels under control conditions and in WT microvessels after every cytokine treatment. ZO-1 immunolabeling showed characteristics similar to that of P-glycoprotein. No change was seen in claudin-5 and occludin immunoreactive area fractions in microvessels. A decrease in aquaporin-4 immunoreactivity was measured in WT microvessels treated by IL-6, which was antagonized by IL-10. CONCLUSION IL-6 produced in microvessels contributes to BBB impairment observed in the APOB-100 mice. We showed that IL-10 partly antagonizes the effects of IL-6 at the BBB.
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Affiliation(s)
- Beáta Barabási
- Institute of Biophysics, Biological Research Centre, Temesvári Krt. 62, Szeged, 6726, Hungary.,Doctoral School of Theoretical Medicine, University of Szeged, Tisza L. Krt. 109, Szeged, 6725, Hungary
| | - Lilla Barna
- Institute of Biophysics, Biological Research Centre, Temesvári Krt. 62, Szeged, 6726, Hungary
| | - Ana Raquel Santa-Maria
- Institute of Biophysics, Biological Research Centre, Temesvári Krt. 62, Szeged, 6726, Hungary.,Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA, 02115, USA
| | - András Harazin
- Institute of Biophysics, Biological Research Centre, Temesvári Krt. 62, Szeged, 6726, Hungary
| | - Réka Molnár
- Institute of Biophysics, Biological Research Centre, Temesvári Krt. 62, Szeged, 6726, Hungary
| | - András Kincses
- Institute of Biophysics, Biological Research Centre, Temesvári Krt. 62, Szeged, 6726, Hungary
| | - Judit P Vigh
- Institute of Biophysics, Biological Research Centre, Temesvári Krt. 62, Szeged, 6726, Hungary
| | - Brigitta Dukay
- Institute of Biochemistry, Biological Research Centre, Temesvári Krt. 62, Szeged, 6726, Hungary
| | - Miklós Sántha
- Institute of Biochemistry, Biological Research Centre, Temesvári Krt. 62, Szeged, 6726, Hungary
| | - Melinda E Tóth
- Institute of Biochemistry, Biological Research Centre, Temesvári Krt. 62, Szeged, 6726, Hungary
| | - Fruzsina R Walter
- Institute of Biophysics, Biological Research Centre, Temesvári Krt. 62, Szeged, 6726, Hungary.
| | - Mária A Deli
- Institute of Biophysics, Biological Research Centre, Temesvári Krt. 62, Szeged, 6726, Hungary.
| | - Zsófia Hoyk
- Institute of Biophysics, Biological Research Centre, Temesvári Krt. 62, Szeged, 6726, Hungary.
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The protective effect and potential mechanisms of eugenol against Salmonella in vivo and in vitro. Poult Sci 2022; 101:101801. [PMID: 35338975 PMCID: PMC8957058 DOI: 10.1016/j.psj.2022.101801] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/15/2022] [Accepted: 02/17/2022] [Indexed: 02/08/2023] Open
Abstract
Salmonella enterica serovar Typhimurium (S. Typhimurium) continues to be a serious concern to the poultry industry as a bacterial foodborne zoonosis, which generally results in intestinal inflammation and barrier dysfunction or even death. Eugenol is a phenolic compound with various pharmacological activities involved antioxidant, anti-inflammatory, and antibacterial effects, which is expected to be an effective nonantibiotic therapy. The purpose of this study was to explore the protective effects of eugenol in the cellular and broiler models of S. Typhimurium infection and the possible underlying mechanisms. The results of animal infection showed that eugenol treatments enhanced the relative weight gains and survival rates of broilers with a reduction of the organ bacterial load and intestinal ultrastructural injury. Moreover, eugenol significantly inhibited the mRNA levels of myeloid differentiation factor 88 (MyD88) and toll-like receptor-4 (TLR4), then declined the phosphorylation of p65 and IκBα of NF-κB pathway and the expressions of inflammatory factors (TNF-α, IL-1β, IL-2, and IL-18) in duodenum tissues, while maintained the expressions of intestinal tight junction proteins (ZO-1, claudin-1, occludin). Further experiments in vitro revealed that eugenol markedly inhibited the adhesion and invasion of S. Typhimurium to RAW264.7 or IEC-6 cells, then reduce bacterial multiplication in IEC-6 or DF-1 cells. In conclusion, eugenol could defend broilers from S. Typhimurium infection by stabilizing the intestinal mucosal barrier and relieving inflammatory response, as well as inhibiting bacterial adhesion and invasion to cells.
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Mogensen FLH, Delle C, Nedergaard M. The Glymphatic System (En)during Inflammation. Int J Mol Sci 2021; 22:7491. [PMID: 34299111 PMCID: PMC8305763 DOI: 10.3390/ijms22147491] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/04/2021] [Accepted: 07/08/2021] [Indexed: 01/15/2023] Open
Abstract
The glymphatic system is a fluid-transport system that accesses all regions of the brain. It facilitates the exchange of cerebrospinal fluid and interstitial fluid and clears waste from the metabolically active brain. Astrocytic endfeet and their dense expression of the aquaporin-4 water channels promote fluid exchange between the perivascular spaces and the neuropil. Cerebrospinal and interstitial fluids are together transported back to the vascular compartment by meningeal and cervical lymphatic vessels. Multiple lines of work show that neurological diseases in general impair glymphatic fluid transport. Insofar as the glymphatic system plays a pseudo-lymphatic role in the central nervous system, it is poised to play a role in neuroinflammation. In this review, we discuss how the association of the glymphatic system with the meningeal lymphatic vessel calls for a renewal of established concepts on the CNS as an immune-privileged site. We also discuss potential approaches to target the glymphatic system to combat neuroinflammation.
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Affiliation(s)
- Frida Lind-Holm Mogensen
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (F.L.-H.M.); (C.D.)
| | - Christine Delle
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (F.L.-H.M.); (C.D.)
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (F.L.-H.M.); (C.D.)
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
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7
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Manouchehrian O, Ramos M, Bachiller S, Lundgaard I, Deierborg T. Acute systemic LPS-exposure impairs perivascular CSF distribution in mice. J Neuroinflammation 2021; 18:34. [PMID: 33514389 PMCID: PMC7844902 DOI: 10.1186/s12974-021-02082-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/13/2021] [Indexed: 12/22/2022] Open
Abstract
Background The exchange of cerebrospinal (CSF) and interstitial fluid is believed to be vital for waste clearance in the brain. The sleep-dependent glymphatic system, which is comprised of perivascular flow of CSF and is largely dependent on arterial pulsatility and astrocytic aquaporin-4 (AQP4) expression, facilitates much of this brain clearance. During the last decade, several observations have indicated that impaired glymphatic function goes hand in hand with neurodegenerative diseases. Since pathologies of the brain carry inflammatory components, we wanted to know how acute inflammation, e.g., with lipopolysaccharide (LPS) injections, would affect the glymphatic system. In this study, we aim to measure the effect of LPS on perivascular CSF distribution as a measure of glymphatic function. Methods Three hours after injection of LPS (1 mg/kg i.p.), C57bl/6 mice were (1) imaged for two CSF tracers, injected into cisterna magna, (2) transcardially perfused with buffer, or (3) used for physiological readouts. Tracer flow was imaged using a low magnification microscope on fixed brains, as well as using vibratome-cut slices for measuring tracer penetration in the brain. Cytokines, glial, and BBB-permeability markers were measured with ELISAs, Western blots, and immunohistochemistry. Cerebral blood flow was approximated using laser Doppler flowmetry, respiration and heart rate with a surgical monitor, and AQP4-polarization was quantified using confocal microscopy of immunolabeled brain sections. Results LPS-injections significantly lowered perivascular CSF tracer flow and penetration into the parenchyma. No differences in AQP4 polarization, cytokines, astroglial and BBB markers, cerebral blood flow, or respiration were detected in LPS-injected mice, although LPS did elevate cortical Iba1+ area and heart rate. Conclusions This study reports another physiological response after acute exposure to the bacterial endotoxin LPS, namely the statistically significant decrease in perivascular distribution of CSF. These observations may benefit our understanding of the role of systemic inflammation in brain clearance.
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Affiliation(s)
- Oscar Manouchehrian
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Science, Lund University, SE-221 84, Lund, Sweden.
| | - Marta Ramos
- Department of Experimental Medical Science, Lund University, SE-221 84, Lund, Sweden.,Wallenberg Centre for Molecular Medicine, Lund University, SE-223 62, Lund, Sweden
| | - Sara Bachiller
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Science, Lund University, SE-221 84, Lund, Sweden
| | - Iben Lundgaard
- Department of Experimental Medical Science, Lund University, SE-221 84, Lund, Sweden.,Wallenberg Centre for Molecular Medicine, Lund University, SE-223 62, Lund, Sweden
| | - Tomas Deierborg
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Science, Lund University, SE-221 84, Lund, Sweden
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8
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Spradley FT. Targeting inflammation to reduce seizure severity in an experimental model of eclampsia. Hypertens Res 2020; 43:350-353. [PMID: 31932641 DOI: 10.1038/s41440-019-0317-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 08/06/2019] [Accepted: 08/06/2019] [Indexed: 11/09/2022]
Affiliation(s)
- Frank T Spradley
- Department of Surgery, The University of Mississippi Medical Center, Jackson, MS, USA.
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9
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Dickson K, Lehmann C. Inflammatory Response to Different Toxins in Experimental Sepsis Models. Int J Mol Sci 2019; 20:ijms20184341. [PMID: 31491842 PMCID: PMC6770119 DOI: 10.3390/ijms20184341] [Citation(s) in RCA: 130] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/27/2019] [Accepted: 09/02/2019] [Indexed: 12/29/2022] Open
Abstract
Sepsis is defined as life-threatening organ dysfunction caused by the dysregulated host response to infection. Despite serious mortality and morbidity, no sepsis-specific drugs exist. Endotoxemia is often used to model the hyperinflammation associated with early sepsis. This model classically uses lipopolysaccharide (LPS) from Gram-negative pathogens to activate the immune system, leading to hyperinflammation, microcirculatory disturbances and death. Other toxins may also be used to activate the immune system including Gram-positive peptidoglycan (PG) and lipoteichoic acid (LTA). In addition to these standard toxins, other bacterial components can induce inflammation. These molecules activate different signaling pathways and produce different physiological responses which can be taken advantage of for sepsis modeling. Endotoxemia modeling can provide information on pathways to inflammation in sepsis and contribute to preclinical drug development.
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Affiliation(s)
- Kayle Dickson
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
| | - Christian Lehmann
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS B3H 4R2, Canada.
- Department of Pharmacology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS B3H 4R2, Canada.
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Setkowicz Z, Kosonowska E, Janeczko K. Inflammation in the developing rat modulates astroglial reactivity to seizures in the mature brain. J Anat 2017; 231:366-379. [PMID: 28597918 DOI: 10.1111/joa.12636] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2017] [Indexed: 11/29/2022] Open
Abstract
Astrocytes participate in neuronal development and excitability, and produce factors enhancing or suppressing inflammatory processes occurring due to neurodegenerative diseases, such as epilepsy. Seizures, in turn, trigger the release of inflammatory mediators, causing structural and functional changes in the brain. Therefore, it appears reasonable to determine whether generalized inflammation at developmental periods can affect astrocyte reactivity to epileptic seizures occurring in the adult brain. Lipopolysaccharide (LPS) was injected in 6- or 30-day-old rats (P6 or P30, respectively). At the age of 2 months, seizures were induced, and pilocarpine and morphological changes of astrocytes located within the hippocampal formation were assessed. Additionally, expression of glial fibrillary acidic protein (GFAP), glutamine synthetase (GS), aquaporin 4 (AQP4), and inwardly rectifying potassium channel Kir 4.1 (Kir4.1) was determined using Western blots. The animal group given LPS on P6 displayed maximal susceptibility to pilocarpine-induced seizures, significantly higher than the group that received LPS on P30. In the immunohistologically examined hippocampal formation, the GFAP-immunoreactive area was not affected by LPS alone. However, it was reduced following seizures in naïve controls but not in LPS-pretreated rats. Increases in the ramification of astrocytic processes were detected only in adult rats given LPS on P30, not on P6. Seizures abolished the effects. Following seizures, the process ramification showed no significant change in the two LPS-treated rat groups, whereas it was significantly reduced in the dentate gyrus of LPS-untreated controls. Glial fibrillary acidic protein (GFAP) expression showed no changes induced with LPS alone and rose slightly after seizures. AQP4 content was lower in rats given LPS on P6 and was seizure-resistant in the two LPS-treated groups, contrary to a decrease in untreated controls. GS expression was not affected by LPS treatments and was reduced after seizures without an intergroup difference. Kir4.1 underwent highly significant increases in all groups experiencing seizures, but LPS alone had no effect. It can be concluded that the generalized inflammatory status led to some important changes in astrocytes reflected, in part at least by permanent modifications of their morphology and molecular profile. Moreover, the previously experienced inflammation prevented the cells from much stronger changes in response to seizures observed in adult untreated controls. The obtained results point to a link between the activation of astrocytes by transient systemic inflammation occurring during the developmental period and their subsequent reactivity to seizures, which may play an important role in the functional features of the brain, including its susceptibility to seizures.
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Affiliation(s)
- Zuzanna Setkowicz
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, Krakow, Poland
| | - Emilia Kosonowska
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, Krakow, Poland
| | - Krzysztof Janeczko
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, Krakow, Poland
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Goldstein J, Carden TR, Perez MJ, Taira CA, Höcht C, Gironacci MM. Angiotensin-(1-7) protects from brain damage induced by shiga toxin 2-producing enterohemorrhagic Escherichia coli. Am J Physiol Regul Integr Comp Physiol 2016; 311:R1173-R1185. [PMID: 27681328 DOI: 10.1152/ajpregu.00467.2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 09/01/2016] [Accepted: 09/13/2016] [Indexed: 01/03/2023]
Abstract
Shiga toxin 2 (Stx2)-producing enterohemorrhagic induced brain damage. Since a cerebroprotective action was reported for angiotensin (Ang)-(1-7), our aim was to investigate whether Ang-(1-7) protects from brain damage induced by Stx2-producing enterohemorrhagic Escherichia coli The anterior hypothalamic area of adult male Wistar rats was injected with saline solution or Stx2 or Stx2 plus Ang-(1-7) or Stx2 plus Ang-(1-7) plus A779. Rats received a single injection of Stx2 at the beginning of the experiment, and Ang-(1-7), A779, or saline was administered daily in a single injection for 8 days. Cellular ultrastructural changes were analyzed by transmission electron microscopy. Stx2 induced neurodegeneration, axonal demyelination, alterations in synapse, and oligodendrocyte and astrocyte damage, accompanied by edema. Ang-(1-7) prevented neuronal damage triggered by the toxin in 55.6 ± 9.5% of the neurons and the Stx2-induced synapse dysfunction was reversed. In addition, Ang-(1-7) blocked Stx2-induced demyelination in 92 ± 4% of the axons. Oligodendrocyte damage caused by Stx2 was prevented by Ang-(1-7) but astrocytes were only partially protected by the peptide (38 ± 5% of astrocytes were preserved). Ang-(1-7) treatment resulted in 50% reduction in the number of activated microglial cells induced by Stx2, suggesting an anti-inflammatory action. All these beneficial effects elicited by Ang-(1-7) were blocked by the Mas receptor antagonist and thus it was concluded that Ang-(1-7) protects mainly neurons and oligodendrocytes, and partially astrocytes, in the central nervous system through Mas receptor stimulation.
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Affiliation(s)
- Jorge Goldstein
- Laboratorio de Neurofisiopatología, Instituto de Fisiología y Biofísica "Houssay"-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Tomás R Carden
- Departamento de Química Biológica, Instituto de Química y Fisicoquímica Biológicas-CONICET, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina; and
| | - María J Perez
- Departamento de Química Biológica, Instituto de Química y Fisicoquímica Biológicas-CONICET, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina; and
| | - Carlos A Taira
- Departamento de Farmacología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Christian Höcht
- Departamento de Farmacología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Mariela M Gironacci
- Departamento de Química Biológica, Instituto de Química y Fisicoquímica Biológicas-CONICET, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina; and
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Leu H, Sugimoto N, Shimizu M, Toma T, Wada T, Ohta K, Yachie A. Tumor necrosis factor-α modifies the effects of Shiga toxin on glial cells. Int Immunopharmacol 2016; 38:139-43. [PMID: 27268285 DOI: 10.1016/j.intimp.2016.05.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 05/16/2016] [Accepted: 05/26/2016] [Indexed: 11/25/2022]
Abstract
Shiga toxin (STX) is one of the main factors inducing hemorrhagic colitis and hemolytic-uremic syndrome (HUS) in infections with STX-producing Escherichia coli (STEC). Approximately 62% of patients with HUS showed symptoms of encephalopathy in the 2011 Japanese outbreak of STEC infections. At that time, we reported elevated serum concentrations of tumor necrosis factor (TNF)-α in patients with acute encephalopathy during the HUS phase. In the current study, we investigated whether TNF-α augments the effects of STX in glial cell lines and primary glial cells. We found that TNF-α alone or STX in combination with TNF-α activates nuclear factor-κB (NF-κB) signaling and inhibits growth of glial cells. The magnitude of the NF-κB activation and the inhibition of cell growth by the STX and TNF-α combination was greater than that obtained with TNF-α alone or STX alone. Thus, this in vitro study reveals the role of TNF-α in glial cells during STEC infections.
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Affiliation(s)
- Hue Leu
- Department of Pediatrics, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan; Dan Phuong General Hospital, Hanoi, Vietnam.
| | - Naotoshi Sugimoto
- Department of Pediatrics, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan; Department of Physiology, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
| | - Masaki Shimizu
- Department of Pediatrics, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
| | - Tomoko Toma
- Department of Pediatrics, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
| | - Taizo Wada
- Department of Pediatrics, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
| | - Kunio Ohta
- Department of Pediatrics, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
| | - Akihiro Yachie
- Department of Pediatrics, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
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