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Morita M, Toida A, Horiuchi Y, Watanabe S, Sasahara M, Kawaguchi K, So T, Imanaka T. Generation of an immortalized astrocytic cell line from Abcd1-deficient H-2K btsA58 mice to facilitate the study of the role of astrocytes in X-linked adrenoleukodystrophy. Heliyon 2021; 7:e06228. [PMID: 33659749 PMCID: PMC7892932 DOI: 10.1016/j.heliyon.2021.e06228] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 11/16/2020] [Accepted: 02/04/2021] [Indexed: 12/27/2022] Open
Abstract
X-linked adrenoleukodystrophy (X-ALD) is an inherited metabolic disease characterized by inflammatory demyelination, and activated astrocytes as well as microglia are thought to be involved in its pathogenesis. Conditionally immortalized astrocytic cell clones were prepared from wild-type or Abcd1-deficient H-2KbtsA58 transgenic mice to study the involvement of astrocytes in the pathogenesis of X-ALD. The established astrocyte clones expressed astrocyte-specific molecules such as Vimentin, S100β, Aldh1L1 and Glast. The conditionally immortalized astrocytes proliferated vigorously and exhibited a compact cell body under a permissive condition at 33 °C in the presence of IFN-γ, whereas they became quiescent and exhibited substantial cell enlargement under a non-permissive condition at 37 °C in the absence of IFN-γ. An Abcd1-deficient astrocyte clone exhibited a decrease in the β-oxidation of very long chain fatty acid (VLCFA) and an increase in cellular levels of VLCFA, typical features of Abcd1-deficiency. Upon stimulation with LPS, the Abcd1-deficient astrocyte clone expressed higher levels of pro-inflammatory genes, such as Il6, Nos2, Ccl2 and Cxcl10, compared to wild-type (WT) astrocytes. Furthermore, the Abcd1-deficient astrocytes produced higher amounts of chondroitin sulfate, a marker of reactive astrocytes. These results suggest that dysfunction of Abcd1 renders astrocytes highly responsive to innate immune stimuli. Conditionally immortalized cell clones which preserve astrocyte properties are a useful tool for analyzing the cellular and molecular pathology of ALD.
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Affiliation(s)
- Masashi Morita
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 930-0194, Japan
| | - Ai Toida
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 930-0194, Japan
| | - Yuki Horiuchi
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 930-0194, Japan
| | - Shiro Watanabe
- Division of Nutritional Biochemistry, Institute of Natural Medicine, University of Toyama, Toyama, 930-0194, Japan
| | - Masakiyo Sasahara
- Department of Pathology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 930-0194, Japan
| | - Kosuke Kawaguchi
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 930-0194, Japan
| | - Takanori So
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, 930-0194, Japan
| | - Tsuneo Imanaka
- Faculty of Pharmaceutical Sciences, Hiroshima International University, Kure, Hiroshima, 737-0112, Japan
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Hupp S, Iliev AI. CSF-1 receptor inhibition as a highly effective tool for depletion of microglia in mixed glial cultures. J Neurosci Methods 2020; 332:108537. [PMID: 31790710 DOI: 10.1016/j.jneumeth.2019.108537] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 10/26/2019] [Accepted: 11/28/2019] [Indexed: 11/15/2022]
Abstract
BACKGROUND A breakthrough in the microglia and macrophages field was the identification of the macrophage colony stimulating factor-1 (CSF-1) as a pro-survival factor. Its pharmacological inhibition in animals depletes rapidly all microglia and macrophages. Microglial depletion in mixed glial cultures has always represented a challenge and none of the existing approaches delivers satisfactory results. NEW METHOD We applied a CSF-1R inhibitor (PLX5622) in primary mouse glial cultures, analyzing microglial dose-responses, starting at different time-points and incubating for various periods of time. RESULTS We used two treatment modalities with 10 μM PLX5622 to deplete microglia: i) immediately after brain homogenization and ii) at day in vitro 12. The application of the inhibitor immediately after cell preparation depleted microglia to 8% at 1 week, to 2% at 4 weeks and to 0.5% at 6 weeks (half-time 3.5 days). When mixed glial cultures were treated starting at day in vitro 12, microglia depletion was slower (half-time 6 days) and not complete, indicating a decreased sensitivity to CSF-1. The remaining astrocytes preserved their proliferation ability, their migration in a scratch wound assay, and their pro-inflammatory (IL-6) response towards lipopolysaccharide. COMPARISON TO EXISTING METHODS The proposed approach for microglial depletion in mixed glial cultures is more effective than other existing methods and is non-toxic to non-microglial cells. CONCLUSIONS CSF-1R inhibitors are effective tools for depleting microglia in mixed glial cultures. Longer maturation of the cultures leads to a diminished sensitivity of microglia towards CSF-1. Thus, the treatment should start as early as possible after glial culture preparation.
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Affiliation(s)
- Sabrina Hupp
- Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012, Bern, Switzerland.
| | - Asparouh I Iliev
- Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012, Bern, Switzerland.
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Ferrer-Acosta Y, Gonzalez-Vega MN, Rivera-Aponte DE, Martinez-Jimenez SM, Martins AH. Monitoring Astrocyte Reactivity and Proliferation in Vitro Under Ischemic-Like Conditions. J Vis Exp 2017. [PMID: 29155711 DOI: 10.3791/55108] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Ischemic stroke is a complex brain injury caused by a thrombus or embolus obstructing blood flow to parts of the brain. This leads to deprivation of oxygen and glucose, which causes energy failure and neuronal death. After an ischemic stroke insult, astrocytes become reactive and proliferate around the injury site as it develops. Under this scenario, it is difficult to study the specific contribution of astrocytes to the brain region exposed to ischemia. Therefore, this article introduces a methodology to study primary astrocyte reactivity and proliferation under an in vitro model of an ischemia-like environment, called oxygen glucose deprivation (OGD). Astrocytes were isolated from 1-4 day-old neonatal rats and the number of non-specific astrocytic cells was assessed using astrocyte selective marker Glial Fibrillary Acidic Protein (GFAP) and nuclear staining. The period in which astrocytes are subjected to the OGD condition can be customized, as well as the percentage of oxygen they are exposed to. This flexibility allows scientists to characterize the duration of the ischemic-like condition in different groups of cells in vitro. This article discusses the timeframes of OGD that induce astrocyte reactivity, hypertrophic morphology, and proliferation as measured by immunofluorescence using Proliferating Cell Nuclear Antigen (PCNA). Besides proliferation, astrocytes undergo energy and oxidative stress, and respond to OGD by releasing soluble factors into the cell medium. This medium can be collected and used to analyze the effects of molecules released by astrocytes in primary neuronal cultures without cell-to-cell interaction. In summary, this primary cell culture model can be efficiently used to understand the role of isolated astrocytes upon injury.
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Affiliation(s)
- Yancy Ferrer-Acosta
- Department of Neuroscience, School of Medicine, Universidad Central del Caribe
| | | | | | | | - Antonio H Martins
- Department of Pharmacology and Toxicology, Medical Sciences, Campus, University of Puerto Rico;
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Effect of different levels of intermittent hypoxia on autophagy of hippocampal neurons. Sleep Breath 2017; 21:791-798. [PMID: 28553681 DOI: 10.1007/s11325-017-1512-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 04/28/2017] [Accepted: 05/15/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE The current study was carried out to assess the effects of different levels of intermittent hypoxia (IH) on autophagy in hippocampal neurons, and explore the extent, frequency and duration of IH for researching on autophagy in hippocampal neurons. METHODS Hippocampal neurons were exposed to different levels of IH. To analyze the oxygen level of neuronal exposure environment, we detected the oxygen concentration in the chamber by O2 analyzer, and monitored the oxygen partial pressure (PO2), carbon dioxide partial pressure (PCO2), and pH in the culture media by blood gas analyzer. After 4-, 8-, and 12-h IH, the morphology and quantity of neurons, as well as the expression of light chain 3 (LC3)-II positive dots were observed by immunofluorescence. The expression of apoptosis marker protein cleaved caspase-3 and autophagy marker protein LC3 were examined by western blotting. RESULTS The oxygen level in the chamber and the neuronal culture media both reached to the values set previously in three models. The level of cleaved caspase-3 and LC3 had no significant changes in IH-1 group. The morphology and quantity had no significant changes, while the levels of cleaved caspase-3 and LC3 were both increased in IH-2 group. The quantity of neurons was reduced significantly, and the chromatin condensed and nuclei fragmented in IH-3 group. CONCLUSIONS The effects of varying degrees of IH on autophagy in hippocampal neurons are different. The IH model, hypoxia phase (1.5% O2, 5% CO2, and balance N2) for 5 min and reoxygenation phase (21% O2, 5% CO2, and balance N2) for 10 min, may be the best condition for researching on autophagy in hippocampal neurons.
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Iizumi T, Takahashi S, Mashima K, Minami K, Izawa Y, Abe T, Hishiki T, Suematsu M, Kajimura M, Suzuki N. A possible role of microglia-derived nitric oxide by lipopolysaccharide in activation of astroglial pentose-phosphate pathway via the Keap1/Nrf2 system. J Neuroinflammation 2016; 13:99. [PMID: 27143001 PMCID: PMC4855896 DOI: 10.1186/s12974-016-0564-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 04/26/2016] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Toll-like receptor 4 (TLR4) plays a pivotal role in the pathophysiology of stroke-induced inflammation. Both astroglia and microglia express TLR4, and endogenous ligands produced in the ischemic brain induce inflammatory responses. Reactive oxygen species (ROS), nitric oxide (NO), and inflammatory cytokines produced by TLR4 activation play harmful roles in neuronal damage after stroke. Although astroglia exhibit pro-inflammatory responses upon TLR4 stimulation by lipopolysaccharide (LPS), they may also play cytoprotective roles via the activation of the pentose phosphate pathway (PPP), reducing oxidative stress by glutathione peroxidase. We investigated the mechanisms by which astroglia reduce oxidative stress via the activation of PPP, using TLR4 stimulation and hypoxia in concert with microglia. METHODS In vitro experiments were performed using cells prepared from Sprague-Dawley rats. Coexisting microglia in the astroglial culture were chemically eliminated using L-leucine methyl ester (LME). Cells were exposed to LPS (0.01 μg/mL) or hypoxia (1 % O2) for 12-15 h. PPP activity was measured using [1-(14)C]glucose and [6-(14)C]glucose. ROS and NO production were measured using 2',7'-dichlorodihydrofluorescein diacetate and diaminofluorescein-FM diacetate, respectively. The involvement of nuclear factor-erythroid-2-related factor 2 (Nrf2), a cardinal transcriptional factor under stress conditions that regulates glucose 6-phosphate dehydrogenase, the rate-limiting enzyme of PPP, was evaluated using immunohistochemistry. RESULTS Cultured astroglia exposed to LPS elicited 20 % increases in PPP flux, and these actions of astroglia appeared to involve Nrf2. However, the chemical depletion of coexisting microglia eliminated both increases in PPP and astroglial nuclear translocation of Nrf2. LPS induced ROS and NO production in the astroglial culture containing microglia but not in the microglia-depleted astroglial culture. LPS enhanced astroglial ROS production after glutathione depletion. U0126, an upstream inhibitor of mitogen-activated protein kinase, eliminated LPS-induced NO production, whereas ROS production was unaffected. U0126 also eliminated LPS-induced PPP activation in astroglial-microglial culture, indicating that microglia-derived NO mediated astroglial PPP activation. Hypoxia induced astroglial PPP activation independent of the microglia-NO pathway. Elimination of ROS and NO production by sulforaphane, a natural Nrf2 activator, confirmed the astroglial protective mechanism. CONCLUSIONS Astroglia in concert with microglia may play a cytoprotective role for countering oxidative stress in stroke.
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Affiliation(s)
- Takuya Iizumi
- Department of Neurology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, 160-8582, Tokyo, Japan
| | - Shinichi Takahashi
- Department of Neurology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, 160-8582, Tokyo, Japan.
| | - Kyoko Mashima
- Department of Neurology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, 160-8582, Tokyo, Japan
| | - Kazushi Minami
- Department of Neurology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, 160-8582, Tokyo, Japan
| | - Yoshikane Izawa
- Department of Neurology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, 160-8582, Tokyo, Japan
| | - Takato Abe
- Department of Neurology, Osaka City University Graduate School of Medicine, Osaka-shi, 545-8585, Osaka , Japan
| | - Takako Hishiki
- Department of Biochemistry, Keio University School of Medicine, Shinjuku-ku, 160-8582, Tokyo, Japan.,Clinical and Translational Research Center, Keio University School of Medicine, Shinjuku-ku, 160-8582, Tokyo, Japan.,JST Exploratory Research for Advanced Technology (ERATO) Suematsu Gas Biology Project, Shinjuku-ku, 160-8582, Tokyo , Japan
| | - Makoto Suematsu
- Department of Biochemistry, Keio University School of Medicine, Shinjuku-ku, 160-8582, Tokyo, Japan.,JST Exploratory Research for Advanced Technology (ERATO) Suematsu Gas Biology Project, Shinjuku-ku, 160-8582, Tokyo , Japan
| | - Mayumi Kajimura
- Department of Biochemistry, Keio University School of Medicine, Shinjuku-ku, 160-8582, Tokyo, Japan.,JST Exploratory Research for Advanced Technology (ERATO) Suematsu Gas Biology Project, Shinjuku-ku, 160-8582, Tokyo , Japan
| | - Norihiro Suzuki
- Department of Neurology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, 160-8582, Tokyo, Japan
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Han Z, Chen F, Ge X, Tan J, Lei P, Zhang J. miR-21 alleviated apoptosis of cortical neurons through promoting PTEN-Akt signaling pathway in vitro after experimental traumatic brain injury. Brain Res 2014; 1582:12-20. [PMID: 25108037 DOI: 10.1016/j.brainres.2014.07.045] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 07/25/2014] [Accepted: 07/29/2014] [Indexed: 12/24/2022]
Abstract
Traumatic brain injury (TBI) is a major cause of chronic disability and death in young adults worldwide. Multiple cellular, molecular and biochemical changes impact the development and outcome of TBI. Neuronal cell apoptosis, which is an important pathological change in secondary brain damage, is crucial to determine the functional recovery after TBI. miR-21, a widely-reported oncogene, which can reduce cell apoptosis in cancer, has been confirmed to be a pronounced up-regulated miRNA after TBI in animal model. Our study is designed to investigate whether miR-21 has the function of antiapoptosis in experimental TBI model in vitro and to explore the possible regulatory mechanism of miR-21 on neuronal apoptosis. The scratch cell injury was performed to mimic TBI-induced apoptosis in neurons, and miR-21 agomir/antagomir was transfected to up-/down-regulate the miR-21 level. Our data suggests that miR-21 can reduce the number of TUNEL-positive neurons. Meanwhile, miR-21 decreased the expression level of PTEN, and increased the phosphorylation of Akt significantly. In neurons transfected with miR-21 agomir, the expression of Bcl-2 was promoted while the caspase-3, caspase-9 and Bax level were down-regulated, which are crucially the downstream apoptosis-related proteins of PTEN-Akt signaling pathway. In conclusion, miR-21 can exert the function of reducing neuronal apoptosis through activating the PTEN-Akt signaling pathway. Our research provides new insights into the molecular mechanisms of neuronal apoptosis following TBI, which reminds that miR-21may be a potential therapeutic target for TBI treatment.
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Affiliation(s)
- Zhaoli Han
- Department of Neurosurgery, Tianjin Neurological Institute General Hospital, Tianjin Medical University, Tianjin 300352, China
| | - Fanglian Chen
- Department of Neurosurgery, Tianjin Neurological Institute General Hospital, Tianjin Medical University, Tianjin 300352, China
| | - Xintong Ge
- Department of Neurosurgery, Tianjin Neurological Institute General Hospital, Tianjin Medical University, Tianjin 300352, China
| | - Jin Tan
- Tianjin Institute of Geriatrics, Tianjin Medical University General Hospital, Tianjin 300352, China
| | - Ping Lei
- Department of Neurosurgery, Tianjin Neurological Institute General Hospital, Tianjin Medical University, Tianjin 300352, China; Tianjin Institute of Geriatrics, Tianjin Medical University General Hospital, Tianjin 300352, China.
| | - Jianning Zhang
- Department of Neurosurgery, Tianjin Neurological Institute General Hospital, Tianjin Medical University, Tianjin 300352, China
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Tang M, Zhao L, Chen Y, Wang L, Zhang X. Angiotensin II protects cortical neurons against oxygen-glucose deprivation-induced injury in vitro.. Biomed Rep 2014; 2:112-116. [PMID: 24649080 DOI: 10.3892/br.2013.182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 10/02/2013] [Indexed: 11/05/2022] Open
Abstract
Ischemic cerebrovascular disease is a common type of cerebrovascular disease and the leading cause of disability and mortality worldwide. Therefore, it is crucial to elucidate its pathogenesis and develop novel therapeutic strategies. This study was performed to investigate whether angiotensin (Ang) II exerts a protective effect against cerebral ischemia/reperfusion (I/R) injury in vitro. The primary cultured neurons were prepared and an I/R model was established by incubation of cortical neurons with Na2S2O4, followed by culture in fresh medium. The protective effect of Ang II and its underlying mechanisms were investigated by morphology observation, MTT assay, flow cytometry analysis and reverse transcription-polymerase chain reaction (RT-PCR). The data demonstrated that Ang II significantly ameliorated the neuronal injury caused by oxygen-glucose deprivation. Furthermore, Ang II increased cell viability through inhibiting cell apoptosis. The RT-PCR results revealed that Ang II was able to reverse the increased bax mRNA and the decreased bcl2 mRNA expression. Of note, the protective activity of Ang II may be attenuated by co-treatment with Ang II type 2 (AT2) receptor blockade (PD123319), but not Ang II type 1 (AT1) receptor blockade (valsartan). These findings suggested that Ang II exerted a protective effect against neuronal injury induced by oxygen-glucose deprivation through decreasing cell apoptosis. Therefore, Ang II may be used as a potential therapeutic target in the future.
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Affiliation(s)
- Mingtan Tang
- Department of Pharmacology, Shandong University School of Medicine, Jinan, Shandong 250012, P.R. China
| | - Li Zhao
- Department of Pharmacology, Shandong University School of Medicine, Jinan, Shandong 250012, P.R. China
| | - Yanqing Chen
- Department of Pharmacology, Shandong University School of Medicine, Jinan, Shandong 250012, P.R. China
| | - Lixiang Wang
- Department of Pharmacology, Shandong University School of Medicine, Jinan, Shandong 250012, P.R. China
| | - Xiumei Zhang
- Department of Pharmacology, Shandong University School of Medicine, Jinan, Shandong 250012, P.R. China
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