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Zaghloul N, Kurepa D, Bader MY, Nagy N, Ahmed MN. Prophylactic inhibition of NF-κB expression in microglia leads to attenuation of hypoxic ischemic injury of the immature brain. J Neuroinflammation 2020; 17:365. [PMID: 33261624 PMCID: PMC7709340 DOI: 10.1186/s12974-020-02031-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 11/10/2020] [Indexed: 11/29/2022] Open
Abstract
Background Periventricular leukomalacia (PVL), a devastating brain injury affecting premature infants, is the most common cause of cerebral palsy. PVL is caused by hypoxia ischemia (HI) and is characterized by white matter necrotic lesions, microglial activation, upregulation of NF-κB, and neuronal death. The microglia is the main cell involved in PVL pathogenesis. The goal of this study was to investigate the role of microglial NF-κB activity and its prophylactic inhibition in a neonate mouse model of HI. Methods Transgenic mice with specific knockout NF-κB in microglia and colony stimulating factor 1 receptor Cre with floxed IKKβ (CSF-1R Cre + IKKβflox/wt ) were used. Postnatal day 5 (P5) mice underwent sham or bilateral temporary carotid artery ligation followed by hypoxia. After HI insult, inflammatory cytokines, volumetric MRI, histopathology, and immunohistochemistry for oligodendroglia and microglial activation markers were analyzed. Long-term neurobehavioral assessment, including grip strength, rotarod, and open field testing, was performed at P60. Results We demonstrate that selective inhibition of NF-κB in microglia decreases HI-induced brain injury by decreasing microglial activation, proinflammatory cytokines, and nitrative stress. Rescue of oligodendroglia is evidenced by immunohistochemistry, decreased ventriculomegaly on MRI, and histopathology. This selective inhibition leads to attenuation of paresis, incoordination, and improved grip strength, gait, and locomotion. Conclusion We conclude that NF-κb activation in microglia plays a major role in the pathogenesis of hypoxic ischemic injury of the immature brain, and its prophylactic inhibition offers significant neuroprotection. Using a specific inhibitor of microglial NF-κB may offer a new prophylactic or therapeutic alternative in preterm infants affected by HI and possibly other neurological diseases in which microglial activation plays a role.
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Affiliation(s)
- Nahla Zaghloul
- Department of Pediatrics, Division of Neonatology, University of Arizona, 1501 N. Campbell Avenue, Tucson, AZ, USA.
| | - Dalibor Kurepa
- Department of Pediatrics, Division of Neonatology, Feinstein Institute for Medical Research, Manhasset, NY, USA
| | - Mohammad Y Bader
- Department of Pediatrics, Division of Neonatology, University of Arizona, 1501 N. Campbell Avenue, Tucson, AZ, USA
| | - Nadia Nagy
- Department of Pediatrics, Division of Neonatology, University of Arizona, 1501 N. Campbell Avenue, Tucson, AZ, USA
| | - Mohamed N Ahmed
- Department of Pediatrics, Division of Neonatology, University of Arizona, 1501 N. Campbell Avenue, Tucson, AZ, USA
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Bandyopadhaya A, Constantinou C, Psychogios N, Ueki R, Yasuhara S, Martyn JAJ, Wilhelmy J, Mindrinos M, Rahme LG, Tzika AA. Bacterial-excreted small volatile molecule 2-aminoacetophenone induces oxidative stress and apoptosis in murine skeletal muscle. Int J Mol Med 2016; 37:867-78. [PMID: 26935176 PMCID: PMC4790710 DOI: 10.3892/ijmm.2016.2487] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 11/04/2015] [Indexed: 12/18/2022] Open
Abstract
Oxidative stress induces mitochondrial dysfunction and facilitates apoptosis, tissue damage or metabolic alterations following infection. We have previously discovered that the Pseudomonas aeruginosa (PA) quorum sensing (QS)-excreted small volatile molecule, 2-aminoacetophenone (2-AA), which is produced in infected human tissue, promotes bacterial phenotypes that favor chronic infection, while also compromising muscle function and dampens the pathogen-induced innate immune response, promoting host tolerance to infection. In this study, murine whole-genome expression data have demonstrated that 2-AA affects the expression of genes involved in reactive oxygen species (ROS) homeostasis, thus producing an oxidative stress signature in skeletal muscle. The results of the present study demonstrated that the expression levels of genes involved in apoptosis signaling pathways were upregulated in the skeletal muscle of 2-AA-treated mice. To confirm the results of our transcriptome analysis, we used a novel high-resolution magic-angle-spinning (HRMAS), proton (1H) nuclear magnetic resonance (NMR) method and observed increased levels of bisallylic methylene fatty acyl protons and vinyl protons, suggesting that 2-AA induces skeletal muscle cell apoptosis. This effect was corroborated by our results demonstrating the downregulation of mitochondrial membrane potential in vivo in response to 2-AA. The findings of the present study indicate that the bacterial infochemical, 2-AA, disrupts mitochondrial functions by inducing oxidative stress and apoptosis signaling and likely promotes skeletal muscle dysfunction, which may favor chronic/persistent infection.
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Affiliation(s)
- Arunava Bandyopadhaya
- Department of Surgery, Microbiology and Immunobiology, Harvard Medical School and Molecular Surgery Laboratory, Center for Surgery, Innovation and Bioengineering, Department of Surgery, Massachusetts General and Shriners Burns Hospitals, Harvard Medical School, Boston, MA 02114, USA
| | - Caterina Constantinou
- Department of Surgery, Microbiology and Immunobiology, Harvard Medical School and Molecular Surgery Laboratory, Center for Surgery, Innovation and Bioengineering, Department of Surgery, Massachusetts General and Shriners Burns Hospitals, Harvard Medical School, Boston, MA 02114, USA
| | - Nikolaos Psychogios
- NMR Surgical Laboratory, Center for Surgery, Innovation and Bioengineering, Department of Surgery, Massachusetts General and Shriners Burns Hospitals, Harvard Medical School, Boston, MA 02114, USA
| | - Ryusuke Ueki
- Department of Anesthesiology and Critical Care, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Shingo Yasuhara
- Department of Anesthesiology and Critical Care, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - J A Jeevendra Martyn
- Department of Anesthesiology and Critical Care, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Julie Wilhelmy
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Michael Mindrinos
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Laurence G Rahme
- Department of Surgery, Microbiology and Immunobiology, Harvard Medical School and Molecular Surgery Laboratory, Center for Surgery, Innovation and Bioengineering, Department of Surgery, Massachusetts General and Shriners Burns Hospitals, Harvard Medical School, Boston, MA 02114, USA
| | - A Aria Tzika
- NMR Surgical Laboratory, Center for Surgery, Innovation and Bioengineering, Department of Surgery, Massachusetts General and Shriners Burns Hospitals, Harvard Medical School, Boston, MA 02114, USA
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3
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Lee BH, Ryu PD, Lee SY. Serum starvation-induced voltage-gated potassium channel Kv7.5 expression and its regulation by Sp1 in canine osteosarcoma cells. Int J Mol Sci 2014; 15:977-93. [PMID: 24434641 PMCID: PMC3907850 DOI: 10.3390/ijms15010977] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Revised: 12/20/2013] [Accepted: 12/30/2013] [Indexed: 01/03/2023] Open
Abstract
The KCNQ gene family, whose members encode Kv7 channels, belongs to the voltage-gated potassium (Kv) channel group. The roles of this gene family have been widely investigated in nerve and muscle cells. In the present study, we investigated several characteristics of Kv7.5, which is strongly expressed in the canine osteosarcoma cell line, CCL-183. Serum starvation upregulated Kv7.5 expression, and the Kv7 channel opener, flupirtine, attenuated cell proliferation by arresting cells in the G0/G1 phase. We also showed that Kv7.5 knockdown helps CCL-183 cells to proliferate. In an effort to find an endogenous regulator of Kv7.5, we used mithramycin A to reduce the level of the transcription factor Sp1, and it strongly inhibited the induction of Kv7.5 in CCL-183 cells. These results suggest that the activation of Kv7.5 by flupirtine may exert an anti-proliferative effect in canine osteosarcoma. Therefore, Kv7.5 is a possible molecular target for canine osteosarcoma therapy.
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Affiliation(s)
- Bo Hyung Lee
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea.
| | - Pan Dong Ryu
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea.
| | - So Yeong Lee
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea.
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4
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Smolders I, Smets I, Maier O, vandeVen M, Steels P, Ameloot M. Simvastatin interferes with process outgrowth and branching of oligodendrocytes. J Neurosci Res 2011; 88:3361-75. [PMID: 20857509 DOI: 10.1002/jnr.22490] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Statins have attracted interest as a treatment option for multiple sclerosis (MS) because of their pleiotropic antiinflammatory and immunomodulatory effects. However, contradictory results have been described when they are applied to oligodendrocytes (OLGs), the cell type predominantly affected in MS. In this study we focus on the in vitro effect of statins on process outgrowth in OLN-93 cells, a well-characterized OLG-derived cell line, and primary cultures of neonatal rat OLGs. Application of the lipophilic simvastatin, as low as 0.1-1 μM, disturbs process formation of both cell types, leading to less ramified cells. We show that both protein isoprenylation and cholesterol synthesis are required for the normal differentiation of OLGs. It is further demonstrated that the expression of 2',3'-cyclic-nucleotide-3' phosphodiesterase (CNP) and tubulin is lowered, concomitant with a reduction of membrane-bound CNP as well as tubulin. Therefore, we propose that lack of isoprenylation of CNP could help to explain the altered morphological and biochemical differentiation state of treated OLGs. Moreover, expression of specific myelin markers, such as myelin basic protein, myelin-associated glycoprotein, and myelin oligodendrocyte glycoprotein, was compromised after treatment. We conclude that simvastatin treatment has detrimental effects on OLG process outgrowth, the prior step in (re)myelination, thereby mortgaging long-term healing of MS lesions.
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Affiliation(s)
- Inge Smolders
- Biomedical Research Institute, School of Life Sciences, Hasselt University and Transnational University Limburg, Diepenbeek, Belgium
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5
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Morphological changes do not reflect biochemical and functional differentiation in OLN-93 oligodendroglial cells. J Neurosci Methods 2009; 184:1-9. [DOI: 10.1016/j.jneumeth.2009.07.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Revised: 07/02/2009] [Accepted: 07/03/2009] [Indexed: 01/31/2023]
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Hyperoxia causes maturation-dependent cell death in the developing white matter. J Neurosci 2008; 28:1236-45. [PMID: 18234901 DOI: 10.1523/jneurosci.3213-07.2008] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Periventricular leukomalacia is the predominant injury in the preterm infant leading to cerebral palsy. Oxygen exposure may be an additional cause of brain injury in these infants. In this study, we investigated pathways of maturation-dependent oligodendrocyte (OL) death induced by hyperoxia in vitro and in vivo. Developing and mature OLs were subjected to 80% oxygen (0-24 h). Lactate dehydrogenase (LDH) assay was used to assess cell viability. Furthermore, 3-, 6-, and 10-d-old rat pups were subjected to 80% oxygen (24 h), and their brains were processed for myelin basic protein staining. Significant cell death was detected after 6-24 h incubation in 80% oxygen in pre-OLs (O4+,O1-), but not in mature OLs (MBP+). Cell death was executed by a caspase-dependent apoptotic pathway and could be blocked by the pan-caspase inhibitor zVAD-fmk. Overexpression of BCL2 (Homo sapiens B-cell chronic lymphocytic leukemia/lymphoma 2) significantly reduced apoptosis. Accumulation of superoxide and generation of reactive oxygen species (ROS) were detected after 2 h of oxygen exposure. Lipoxygenase inhibitors 2,3,5-trimethyl-6-(12-hydroxy-5-10-dodecadiynyl-1,4-benzoquinone and N-benzyl-N-hydroxy-5-phenylpentamide fully protected the cells from oxidative injury. Overexpression of superoxide dismutase (SOD1) dramatically increased injury to pre-OLs but not to mature OLs. We extended these studies by testing the effects of hyperoxia on neonatal white matter. Postnatal day 3 (P3) and P6 rats, but not P10 pups, showed bilateral reduction in MBP (myelin basic protein) expression with 24 h exposure to 80% oxygen. Hyperoxia causes oxidative stress and triggers maturation-dependent apoptosis in pre-OLs, which involves the generation of ROS and caspase activation, and leads to white matter injury in the neonatal rat brain. These observations may be relevant to white matter injury observed in premature infants.
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7
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Dörr J, Roth K, Zurbuchen U, Deisz R, Bechmann I, Lehmann TN, Meier S, Nitsch R, Zipp F. Tumor-necrosis-factor-related apoptosis-inducing-ligand (TRAIL)-mediated death of neurons in living human brain tissue is inhibited by flupirtine-maleate. J Neuroimmunol 2005; 167:204-9. [PMID: 16043230 DOI: 10.1016/j.jneuroim.2005.06.027] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2005] [Accepted: 06/27/2005] [Indexed: 01/18/2023]
Abstract
Neuronal damage mediated by the TRAIL-system might be involved in the pathogenesis of neuroinflammatory diseases of the central nervous system. Here we used an investigator-independent approach to quantify TRAIL-mediated death of total CNS cells and neurons in a living human brain slice culture system, a model which is much closer to the in vivo situation than dissociated cell culture. We observed dose-dependent TRAIL-mediated death of both total human CNS cells and neurons, which was prevented by flupirtine-maleate, a centrally acting analgesic drug with proposed neuroprotective properties. Our data suggest flupirtine-maleate as an orally available neuroprotective approach in the course of neuroinflammation.
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Affiliation(s)
- Jan Dörr
- Institute of Neuroimmunology, Neuroscience Research Center, Charité, University-Medicine, NWFZ 2680, Charité, 10098 Berlin, Germany
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8
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Abstract
Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system. The pathological hallmarks of MS lesions in the brain and spinal cord are inflammation, demyelination, axon loss and gliosis. Recent studies revealed heterogeneity in the mechanisms leading to the formation of lesions, which include typical autoimmune patterns of demyelination involving T cells and macrophages, as well as antibody/complement as characteristic effector mechanisms. Additionally, oligodendrocyte dystrophy patterns of demyelination, with disturbances of oligodendroglial myelin protein expression and oligodendrocyte apoptosis, were observed. Treatment of MS has advanced dramatically in recent years, with the introduction of beta-interferons, glatiramer acetate and mitoxantrone. However, not all MS patients respond well to treatment with these drugs, and this may be a consequence of disease heterogeneity. Although immunomodulatory therapy has been clinically proven to be effective in patients with relapsing-remitting MS, studies in secondary-progressive MS patients have only demonstrated a positive therapeutic effect with interferon beta-1b. The pathology and pathogenesis of lesions suggest the need for a subtype-specific treatment, which may be possible when observations from pathology can be acted upon in the living MS patient. In addition to myelin and oligodendrocyte damage, the loss of axons represents another key element of MS lesions that lacks a therapeutic approach. However, axon-protective therapy is yet to be established and the mechanisms and effector molecules involved in axonal degeneration are still to be defined.
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Affiliation(s)
- Wolfgang Brück
- Institute of Neuropathology, Georg-August University Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany.
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9
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Guillemard E, Jacquemot C, Aillet F, Schmitt N, Barré-Sinoussi F, Israël N. Human immunodeficiency virus 1 favors the persistence of infection by activating macrophages through TNF. Virology 2004; 329:371-80. [PMID: 15518816 DOI: 10.1016/j.virol.2004.08.030] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2004] [Revised: 02/03/2004] [Accepted: 08/02/2004] [Indexed: 10/26/2022]
Abstract
Macrophages play a major role in HIV-1 persistence. In the present paper, we demonstrate that the absence of apoptosis in HIV-1-infected primary human monocyte-differentiated macrophages (MDM) correlates with an increase in anti-apoptotic (Bcl-2 and Bcl-x(L)) and a decrease in pro-apoptotic (Bax and Bad) proteins. This is associated with macrophage activation as shown by tumor necrosis factor (TNF) production and NF-kappaB activation upon infection. TNF production was shown to be involved in the upregulation of Bcl-2 and Bcl-x(L) because this increase was abolished by an anti-TNF anti-serum or an inhibitor of TNF synthesis. In parallel, inhibition of TNF production induced an increase in the number of apoptotic cells. Furthermore, using an inhibitor of NF-kappaB activation, we demonstrated that TNF-induced upregulation of Bcl-x(L) and Bcl-2 occurs, respectively, through a NF-kappaB-dependent and an NF-kappaB-independent pathway.
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Affiliation(s)
- Eric Guillemard
- Unité de Biologie des Rétrovirus, Institut Pasteur, 75724 Paris Cedex 15, France
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10
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Saini HS, Gorse KM, Boxer LM, Sato-Bigbee C. Neurotrophin-3 and a CREB-mediated signaling pathway regulate Bcl-2 expression in oligodendrocyte progenitor cells. J Neurochem 2004; 89:951-61. [PMID: 15140194 DOI: 10.1111/j.1471-4159.2004.02365.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Our previous results suggested that the transcription factor CREB mediates the actions of neuroligands and growth factor signals that coupled to different signaling pathways may play different roles along oligodendrocyte (OLG) development. We showed before that CREB phosphorylation in OLG progenitors is up-regulated by neurotrophin-3 (NT-3); and moreover CREB is required for NT-3 to stimulate the proliferation of these cells. We now show that treatment of OLG progenitors with NT-3 is also accompanied by an increase in the levels of the anti-apoptotic protein Bcl-2. Interestingly, the presence of a putative CREB binding site (CRE) in the Bcl-2 gene raised the possibility that CREB could also be involved in regulating Bcl-2 expression in the OLGs. Supporting this hypothesis, the NT-3 dependent increase in Bcl-2 levels is abolished by inhibition of CREB expression. In addition, transient transfection experiments using various regions of the Bcl-2 promoter and mutation of the CRE site indicate a direct role of CREB in regulating Bcl-2 gene activity in response to NT-3. Furthermore, protein-DNA binding assays show that the CREB protein from freshly isolated OLGs indeed binds to the Bcl-2 promoter CRE. Together with our previous results, these observations suggest that CREB may play an important role in linking proliferation and survival pathways in the OLG progenitors.
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Affiliation(s)
- Harsimran S Saini
- Department of Biochemistry, Virginia Commonwealth University School of Medicine, Richmond, Virginia 23298, USA
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Khorchid A, Fragoso G, Shore G, Almazan G. Catecholamine-induced oligodendrocyte cell death in culture is developmentally regulated and involves free radical generation and differential activation of caspase-3. Glia 2002; 40:283-99. [PMID: 12420309 DOI: 10.1002/glia.10123] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Oligodendrocyte cultures were used to study the toxic effects of catecholamines. Our results showed that catecholamine-induced toxicity was dependent on the dose of dopamine or norepinephrine used and on the developmental stage of the cultures, with oligodendrocyte progenitors being more vulnerable. A role for oxidative stress and apoptosis on the mechanism of action of catecholamines on oligodendrocyte cell death was next assessed. Catecholamines caused a reduction in intracellular glutathione levels, an accumulation in reactive oxygen species and in heme oxygenase-1, the 32 kDa stress-induced protein. All these changes were prevented by N-acetyl-L-cysteine, a thiocompound with antioxidant activity and a precursor of glutathione, and were more pronounced in progenitors than mature cells, which could contribute to their higher susceptibility. Apoptotic cell death, as assessed by activation of caspase-9 and -3 and cleavage of poly(ADP-ribose) polymerase (a substrate of caspase-3), was only observed in oligodendrocyte progenitors. Pretreatment with zVAD, a general caspase inhibitor, prevented activation of caspase-9 and -3, DNA fragmentation, and decreased progenitors cell death. Furthermore, the expression levels of procaspase-3 and the ratio of the proapoptotic protein bax to antiapoptotic protein bcl-xl were several folds higher in immature than mature oligodendrocytes. Taken together, these results strongly suggest that the catecholamine-induced cytotoxicity in oligodendrocytes is developmentally regulated, mediated by oxidative stress, and have characteristics of apoptosis in progenitor cells.
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Affiliation(s)
- Amani Khorchid
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
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Kuhlmann T, Glas M, zum Bruch C, Mueller W, Weber A, Zipp F, Brück W. Investigation of bax, bcl-2, bcl-x and p53 gene polymorphisms in multiple sclerosis. J Neuroimmunol 2002; 129:154-60. [PMID: 12161031 DOI: 10.1016/s0165-5728(02)00167-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Clinical course, outcome, radiological features, severity, and histopathology are heterogenous in multiple sclerosis (MS). Since MS is considered to be a polygenic disease, the genetic background may at least partly be responsible for this variability. Some MS cases are histopathologically characterized by a dramatic oligodendrocyte loss that is in part caused by apoptosis. A dysregulated apoptotic elimination of self-reactive T cells may also contribute to disease susceptibility. To analyze genetic differences in the apoptosis regulating factors bcl-2, bax, bcl-x and p53 we investigated polymorphisms of these genes in 105 patients with a relapsing remitting disease course and 99 controls by PCR-SSCP and direct sequencing. We identified so far unpublished sequence alterations in the promotor region of the bxl-x gene, in exon 7 of the p53 gene, and in exon 1 of the bax gene. No differences were observed between MS patients and controls. Additional known polymorphisms were found in intron 3 of the bax gene and in exon 6 of the p53 gene. No significant differences in the frequency of gene sequence variations were found between MS patients and controls. The apoptosis genes studied here therefore appear less likely to be important effector genes in MS.
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Affiliation(s)
- T Kuhlmann
- Department of Neuropathology, Charité, Campus Virchow-Klinikum, Humboldt-Universität, Augustenburger Platz 1, 13353, Berlin, Germany
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Sasson R, Winder N, Kees S, Amsterdam A. Induction of apoptosis in granulosa cells by TNF alpha and its attenuation by glucocorticoids involve modulation of Bcl-2. Biochem Biophys Res Commun 2002; 294:51-9. [PMID: 12054739 DOI: 10.1016/s0006-291x(02)00431-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Tumor necrosis factor alpha (TNF alpha) plays a role in mammalian ovarian follicular development, steroidogenesis, ovulation, luteolysis, and atresia, but the exact mechanism of TNF alpha action is not completely understood. Induction of apoptosis and suppression of steroidogenesis by TNF alpha in primary preovulatory rat and human granulosa cells, as well as, in human granulosa cells immortalized by mutated p53, were characterized in the present work. Dexamethasone (Dex) and hydrocortisone efficiently suppressed TNF alpha-induced apoptosis in granulosa cells. TNF alpha dramatically reduced intracellular levels of Bcl-2, while Dex abrogated this reduction. TNF alpha reduced considerably intracellular levels of StAR protein, a key regulating factor in steroidogenesis. This reduction can be explained only in part by elimination of cells through apoptosis, since loss of steroidogenic capacity was much higher and faster than the rate and extent of loss of cell viability induced by TNF alpha, suggesting independent mechanisms for TNF alpha-induction of apoptosis and TNF alpha-suppression of steroidogenesis.
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Affiliation(s)
- Ravid Sasson
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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Dhar S, Bitting RL, Rylova SN, Jansen PJ, Lockhart E, Koeberl DD, Amalfitano A, Boustany RMN. Flupirtine blocks apoptosis in batten patient lymphoblasts and in human postmitotic CLN3- and CLN2-deficient neurons. Ann Neurol 2002; 51:448-66. [PMID: 11921051 DOI: 10.1002/ana.10143] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Multiple gene defects cause Batten disease. Accelerated apoptosis accounts for neurodegeneration in the late infantile and juvenile forms that are due to defects in the CLN3 and CLN2 genes. Extensive neuronal death is seen in CLN2- and CLN3-deficient human brain as well as in CLN6-deficient sheep brain and retina. When neurons in late infantile and juvenile brain survive, they manage to do so by upregulating the neuroprotective molecule Bcl-2. The CLN3 gene has antiapoptotic properties at the molecular level. We show that the CLN2 gene is neuroprotective: it enhances growth of NT2 cells and maintains survival of human postmitotic hNT neurons. Conversely, blocking CLN3 or CLN2 expression in hNT neurons with adenoviral antisense-CLN3 or antisense-CLN2-AAV2 constructs causes apoptosis. The drug flupirtine is a triaminopyridine derivative that acts as a nonopioid analgesic. Flupirtine upregulates Bcl-2, increases glutathione levels, activates an inwardly rectifying potassium channel, and delays loss of intermitochondrial membrane calcium retention capacity. We show that flupirtine aborts etoposide-induced apoptosis in CLN1-, CLN2-, CLN3-, and CLN6-deficient as well as normal lymphoblasts. Flupirtine also prevents the death of CLN3- and CLN2-deficient postmitotic hNT neurons at the mitochondrial level. We show that a mechanism of neuroprotection exerted by flupirtine involves complete functional antagonism of N-methyl-D-aspartate or N-methyl-D-aspartate-induced neuronal apoptosis. Flupirtine may be useful as a drug capable of halting the progression of neurodegenerative diseases caused by dysregulated apoptosis.
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Affiliation(s)
- Sumeer Dhar
- Department of Pediatrics, Duke University Medical Center, Durham, NC 27710, USA
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15
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Abstract
Brain injury in the premature infant is a problem of enormous importance. Periventricular leukomalacia (PVL) is the major neuropathologic form of this brain injury and underlies most of the neurologic morbidity encountered in survivors of premature birth. Prevention of PVL now seems ultimately achievable because of recent neurobiologic insights into pathogenesis. The pathogenesis of this lesion relates to three major interacting factors. The first two of these, an incomplete state of development of the vascular supply to the cerebral white matter, and a maturation-dependent impairment in regulation of cerebral blood flow underlie a propensity for ischemic injury to cerebral white matter. The third major pathogenetic factor is the maturation-dependent vulnerability of the oligodendroglial (OL) precursor cell that represents the major cellular target in PVL. Recent neurobiologic studies show that these cells are exquisitely vulnerable to attack by free radicals, known to be generated in abundance with ischemia-reperfusion. This vulnerability of OLs is maturation-dependent, with the OL precursor cell highly vulnerable and the mature OL resistant, and appears to relate to a developmental window characterized by a combination of deficient antioxidant defenses and active acquisition of iron during OL differentiation. The result is generation of deadly reactive oxygen species and apoptotic OL death. Important contributory factors in pathogenesis interact with this central theme of vulnerability to free radical attack. Thus, the increased likelihood of PVL in the presence of intraventricular hemorrhage could relate to increases in local iron concentrations derived from the hemorrhage. The important contributory role of maternal/fetal infection or inflammation and cytokines in the pathogenesis of PVL could be related to effects on the cerebral vasculature and cerebral hemodynamics, to generation of reactive oxygen species, or to direct toxic effects on vulnerable OL precursors. A key role for elevations in extracellular glutamate, caused by ischemia-reperfusion, is suggested by demonstrations that glutamate causes toxicity to OL precursors by both nonreceptor- and receptor-mediated mechanisms. The former involves an exacerbation of the impairment in antioxidant defenses, and the latter, an alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate receptor-mediated cell death. Most importantly, these new insights into the pathogenesis of PVL suggest potential preventive interventions. These include avoidance of cerebral ischemia by detection of infants with impaired cerebrovascular autoregulation, e.g. through the use of in vivo near-infrared spectroscopy, the use of free radical scavengers to prevent toxicity by reactive oxygen species, the administration of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate receptor antagonists to prevent glutamate-mediated injury, or the use of maternal antibiotics or anticytokine agents to prevent toxicity from maternal/fetal infection or inflammation and cytokines.
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Affiliation(s)
- J J Volpe
- Department of Neurology, Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
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Tanaka K, Nogawa S, Ito D, Suzuki S, Dembo T, Kosakai A, Fukuuchi Y. Phosphorylation of cyclic adenosine monophosphate response element binding protein in oligodendrocytes in the corpus callosum after focal cerebral ischemia in the rat. J Cereb Blood Flow Metab 2001; 21:1177-88. [PMID: 11598495 DOI: 10.1097/00004647-200110000-00006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Phosphorylation of cyclic adenosine monophosphate (AMP) response element binding protein (CREB) was examined immunohistochemically in the corpus callosum of the rat brain at various time points after 90-minute focal cerebral ischemia. Focal ischemia was induced by occlusion of the middle cerebral artery (MCA) using the intraluminal suture method. Sham animals showed that numerous oligodendrocytes (OLGs) constitutively express unphosphorylated CREB. Local cerebral blood flow (lCBF) measured by the 14C-iodoantipyrine method was reduced from 44.2 +/- 15.4 (mL 100 g(-1) min(-1)) to 18.4 +/- 3.8 and from 53.9 +/- 14.4 to 4.8 +/- 4.5 in the medial and the lateral regions of the corpus callosum, respectively, during MCA occlusion (MCAO). After release of the MCAO, lCBF recovered to the control level in each region. The medial region of the corpus callosum showed a marked increase in phosphorylated CREB-positive OLGs at 3.5 hours of recirculation, and it remained increased until 2 weeks of recirculation as it gradually declined. The activation of CREB phosphorylation in the OLGs was accompanied by expression of antiapoptotic protein bcl-2, normal staining with cresyl violet, and negative TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling) staining. Myelination detected by immunostaining with anti-myelin basic protein (MBP) antibody and anti-myelin associated glycoprotein (MAG) antibody remained normal in the medial region of the corpus callosum. The lateral region of the corpus callosum showed a significant but only transient increase in phosphorylated CREB-positive OLGs at 3.5 hours of recirculation, which was followed by a rapid decrease during the subsequent recirculation period. Expression of bcl-2 was suppressed in this region, and demyelination became apparent. These findings suggest that signal transduction through CREB phosphorylation may be closely associated with survival of OLGs and maintenance of myelination in the corpus callosum after cerebral ischemia.
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Affiliation(s)
- K Tanaka
- Department of Neurology, School of Medicine, Keio University, Tokyo, Japan
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