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Mäkelä J, Mudò G, Pham DD, Di Liberto V, Eriksson O, Louhivuori L, Bruelle C, Soliymani R, Baumann M, Korhonen L, Lalowski M, Belluardo N, Lindholm D. Peroxisome proliferator-activated receptor-γ coactivator-1α mediates neuroprotection against excitotoxic brain injury in transgenic mice: role of mitochondria and X-linked inhibitor of apoptosis protein. Eur J Neurosci 2016; 43:626-39. [PMID: 26741810 DOI: 10.1111/ejn.13157] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 12/03/2015] [Accepted: 12/29/2015] [Indexed: 01/08/2023]
Abstract
Peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) is a transcriptional coactivator involved in the regulation of mitochondrial biogenesis and cell defense. The functions of PGC-1α in physiology of brain mitochondria are, however, not fully understood. To address this we have studied wild-type and transgenic mice with a two-fold overexpression of PGC-1α in brain neurons. Data showed that the relative number and basal respiration of brain mitochondria were increased in PGC-1α transgenic mice compared with wild-type mitochondria. These changes occurred concomitantly with altered levels of proteins involved in oxidative phosphorylation (OXPHOS) as studied by proteomic analyses and immunoblottings. Cultured hippocampal neurons from PGC-1α transgenic mice were more resistant to cell degeneration induced by the glutamate receptor agonist kainic acid. In vivo kainic acid induced excitotoxic cell death in the hippocampus at 48 h in wild-type mice but significantly less so in PGC-1α transgenic mice. However, at later time points cell degeneration was also evident in the transgenic mouse hippocampus, indicating that PGC-1α overexpression can induce a delay in cell death. Immunoblotting showed that X-linked inhibitor of apoptosis protein (XIAP) was increased in PGC-1α transgenic hippocampus with no significant changes in Bcl-2 or Bcl-X. Collectively, these results show that PGC-1α overexpression contributes to enhanced neuronal viability by stimulating mitochondria number and respiration and increasing levels of OXPHOS proteins and the anti-apoptotic protein XIAP.
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Affiliation(s)
- Johanna Mäkelä
- Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki, POB 63, 00014, Haartmaninkatu 8, FIN-00290, Helsinki, Finland.,Minerva Medical Research Institute, Biomedicum-2 Helsinki, Tukholmankatu 8, FIN-00290 Helsinki, Finland
| | - Giuseppa Mudò
- Department of Experimental Biomedicine and Clinical Neuroscience, Division of Human Physiology, University of Palermo, Corso Tukory 129, I-90134 Palermo, Italy
| | - Dan Duc Pham
- Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki, POB 63, 00014, Haartmaninkatu 8, FIN-00290, Helsinki, Finland.,Minerva Medical Research Institute, Biomedicum-2 Helsinki, Tukholmankatu 8, FIN-00290 Helsinki, Finland
| | - Valentina Di Liberto
- Department of Experimental Biomedicine and Clinical Neuroscience, Division of Human Physiology, University of Palermo, Corso Tukory 129, I-90134 Palermo, Italy
| | - Ove Eriksson
- Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki, POB 63, 00014, Haartmaninkatu 8, FIN-00290, Helsinki, Finland
| | - Lauri Louhivuori
- Medicum, Department of Physiology, University of Helsinki, Helsinki, Finland
| | - Céline Bruelle
- Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki, POB 63, 00014, Haartmaninkatu 8, FIN-00290, Helsinki, Finland.,Minerva Medical Research Institute, Biomedicum-2 Helsinki, Tukholmankatu 8, FIN-00290 Helsinki, Finland
| | - Rabah Soliymani
- Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki, POB 63, 00014, Haartmaninkatu 8, FIN-00290, Helsinki, Finland
| | - Marc Baumann
- Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki, POB 63, 00014, Haartmaninkatu 8, FIN-00290, Helsinki, Finland
| | - Laura Korhonen
- Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki, POB 63, 00014, Haartmaninkatu 8, FIN-00290, Helsinki, Finland.,Clinicum, Division of Child Psychiatry, Helsinki University Central Hospital, Helsinki, Finland
| | - Maciej Lalowski
- Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki, POB 63, 00014, Haartmaninkatu 8, FIN-00290, Helsinki, Finland
| | - Natale Belluardo
- Department of Experimental Biomedicine and Clinical Neuroscience, Division of Human Physiology, University of Palermo, Corso Tukory 129, I-90134 Palermo, Italy
| | - Dan Lindholm
- Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki, POB 63, 00014, Haartmaninkatu 8, FIN-00290, Helsinki, Finland.,Minerva Medical Research Institute, Biomedicum-2 Helsinki, Tukholmankatu 8, FIN-00290 Helsinki, Finland
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Johnson EA, Svetlov SI, Wang KKW, Hayes RL, Pineda JA. Cell-specific DNA fragmentation may be attenuated by a survivin-dependent mechanism after traumatic brain injury in rats. Exp Brain Res 2005; 167:17-26. [PMID: 16193270 DOI: 10.1007/s00221-005-2362-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2004] [Accepted: 03/23/2005] [Indexed: 01/02/2023]
Abstract
Survivin attenuates apoptosis by inhibiting cleavage of some cell proteins by activated caspase-3. We recently discovered strong up-regulation of survivin, primarily in astrocytes and a sub-set of neurons, after traumatic brain injury (TBI) in rats. In this study we characterized co-expression of survivin with activated caspase-3 and downstream DNA fragmentation (TUNEL) in astrocytes and neurons after TBI. Western blot analysis revealed significant time-dependent increases in active caspase-3 between 5 and 14 days post-injury. No difference was observed between the proportion of survivin-positive and survivin-negative cells labeled with active caspase-3 at 5 or 7 days post-injury, as indicated by dual fluorescent immunostaining. Labeling of survivin-negative cells with TUNEL was, however, significantly greater than for survivin-positive cells, suggesting that expression of survivin may attenuate DNA cleavage and progression of apoptosis. A higher proportion of astrocytes than neurons accumulated active caspase-3. In contrast, co-localization with TUNEL was significantly higher for neurons than for astrocytes. These data suggest that survivin expression may attenuate DNA cleavage and cell death, and that this mechanism operates in a cell type-specific manner after TBI.
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Affiliation(s)
- Erik A Johnson
- Center for Traumatic Brain Injury Studies (CTBIS), E.F and W.L. McKnight Brain Institute of the University of Florida, Gainesville, FL 32610, USA
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Dong H, Csernansky CA, Chu Y, Csernansky JG. Intracerebroventricular kainic acid administration to neonatal rats alters interneuron development in the hippocampus. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2003; 145:81-92. [PMID: 14519496 DOI: 10.1016/s0165-3806(03)00216-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The effects of neonatal exposure to excitotoxins on the development of interneurons have not been well characterized, but may be relevant to the pathogenesis of neuropsychiatric disorders. In this study, the excitotoxin, kainic acid (KA) was administered to rats at postnatal day 7 (P7) by intracerebroventricular (i.c.v.) infusion. At P14, P25, P40 and P60, Nissl staining and immunohistochemical studies with the interneuron markers, glutamic acid decarboxylase (GAD-67), calbindin-D28k (CB) and parvalbumin (PV) were performed in the hippocampus. In control animals, the total number of interneurons, as well as the number of interneurons stained with GAD-67, CB and PV, was nearly constant from P14 through P60. In KA-treated rats, Nissl staining, GAD-67 staining, and CB staining revealed a progressive decline in the overall number of interneurons in the CA1 and CA3 subfields from P14 to P60. In contrast, PV staining in KA-treated rats showed initial decreases in the number of interneurons in the CA1 and CA3 subfields at P14 followed by increases that approached control levels by P60. These results suggest that, in general, early exposure to the excitotoxin KA decreases the number of hippocampal interneurons, but has a more variable effect on the specific population of interneurons labeled by PV. The functional impact of these changes may be relevant to the pathogenesis of neuropsychiatric disorders, such as schizophrenia.
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Affiliation(s)
- Hongxin Dong
- Department of Psychiatry, Washington University School of Medicine, Campus Box 8134, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
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Korhonen L, Belluardo N, Mudo G, Lindholm D. Increase in Bcl-2 phosphorylation and reduced levels of BH3-only Bcl-2 family proteins in kainic acid-mediated neuronal death in the rat brain. Eur J Neurosci 2003; 18:1121-34. [PMID: 12956712 DOI: 10.1046/j.1460-9568.2003.02826.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Kainic acid induces excitotoxicity and nerve cell degeneration in vulnerable regions of rat brain, most markedly in hippocampus and amygdala. Part of the cell death following kainic acid is apoptotic as shown by caspase 3 activation and chromatin condensation. Here we have studied the regulation of pro- and anti-apoptotic proteins belonging to the Bcl-2 family in rat hippocampus and amygdala by kainic acid in relationship to ensuing neuronal death. The pro-apoptotic protein Bax was up-regulated in hippocampus 6 h after kainic acid administration. The increase in Bax was followed by the appearance of TdT-mediated dUTP nick end labelling-positive cells which were prominent at 24 h. Immunohistochemistry for active Bax revealed a punctuated labelling of neurons in the CA3 and hilar regions of hippocampus as well as in amygdala. Double staining for NeuN, a marker for nerve cells, and TdT-mediated dUTP nick end labelling showed that mainly neurons undergo degeneration after kainic acid treatment. In contrast to Bax, the pro-apoptotic BH3-only Bcl-2 proteins Bim and Harakiri/DP5 were down-regulated by kainic acid. This was also observed for the anti-apoptotic proteins Bcl-x and Bcl-w. Immunoreactive Bcl-2 was up-regulated in hippocampus after kainic acid together with an increase in the phosphorylation of serine-87 in Bcl-2, suggesting a post-transcriptional modification of the protein. This was confirmed using immunoprecipitation of total Bcl-2 from hippocampus and amygdala which revealed an increase in serine-87 phospho-Bcl-2 after kainic acid. Inhibition of the c-jun N-terminal protein kinase pathway reduced both serine-87 phosphorylation and cell death after kainic acid. This indicates an important role of Bcl-2 phosphorylation in controlling neuronal death after kainic acid. In contrast to the situation in trophic factor-deprived neurons, no up-regulation of Bim or Harakiri/DP5 proteins occurred after kainic acid, suggesting alternative pathways for regulation of cell death in excitotoxicity. The results indicate that not only the relative levels of Bcl-2 family proteins but also conformation changes and post-translational modifications contribute to neuronal death following kainic acid.
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Affiliation(s)
- Laura Korhonen
- Department of Neuroscience, Neurobiology, Uppsala University, BMC, Box 587, S-751 23 Uppsala, Sweden
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Trapp T, Korhonen L, Besselmann M, Martinez R, Mercer EA, Lindholm D. Transgenic mice overexpressing XIAP in neurons show better outcome after transient cerebral ischemia. Mol Cell Neurosci 2003; 23:302-13. [PMID: 12812761 DOI: 10.1016/s1044-7431(03)00013-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
X-chromosome linked inhibitor of apoptosis protein (XIAP) is a member of the inhibitor of apoptosis protein (IAP) family and known to inhibit death of various cells under different experimental conditions. Although present in brain tissue, little is known about the physiology of the IAPs in nerve cells. Here we report on the establishment of transgenic mice with overexpression of human XIAP in brain neurons. The mice developed normally, and were more resistant to brain injury caused by transient forebrain ischemia after occlusion of the middle cerebral artery compared to control mice. The XIAP transgenic animals exhibited significantly smaller brain damage, as shown by TUNEL labelling, less reduction in brain protein synthesis, and less active caspase-3 after ischemia compared with controls. Upregulation of RhoB, which is an early indicator of neurological damage, was markedly reduced in the XIAP-overexpressing mice, which had also a better neurological outcome than control animals. This together with the increase in XIAP in normal mouse brain in regions surviving the infarct demonstrates that XIAP is an important factor promoting neuronal survival after ischemia. The results suggest that interference with the levels and the activity of XIAP in neurons may provide targets for the development of drugs limiting neuronal death after ischemia, and possibly in other brain injuries.
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Affiliation(s)
- Thorsten Trapp
- Department of Experimental Neurology, Max Planck Institute for Neurological Research, Gleueler Strasse 50, 50931, Cologne, Germany
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Korhonen L, Brännvall K, Skoglösa Y, Lindholm D. Tumor suppressor gene BRCA-1 is expressed by embryonic and adult neural stem cells and involved in cell proliferation. J Neurosci Res 2003; 71:769-76. [PMID: 12605402 DOI: 10.1002/jnr.10546] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BRCA-1 is a tumor suppressor gene that plays a role in DNA repair and cellular growth control. Here we show that BRCA-1 mRNA is expressed by embryonic rat brain and is localized to the neuroepithelium containing neuronal precursor cells. The expression of BRCA-1 decreases during rat brain development, but BRCA-1 is expressed postnatally by proliferating neuronal precursor cells in the developing cerebellum. Neural stem cells (NSC) prepared from embryonic rat brain and cultured in the presence of epidermal growth factor were positive for BRCA-1. Induction of NSC differentiation resulted in down-regulation of BRCA-1 expression as shown by RNA and protein analyses. In addition to embryonic cells, BRCA-1 is also present in NSC prepared from adult rat brain. In adult rats, BRCA1 was expressed by cells in the walls of brain ventricles and in choroid plexus. The results show that BRCA-1 is present in embryonic and adult rat NSC and that the expression is linked to NSC proliferation.
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Affiliation(s)
- L Korhonen
- Department of Neuroscience, Neurobiology, Uppsala University, Biomedical Centre, Uppsala, Sweden
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Yu LY, Korhonen L, Martinez R, Jokitalo E, Chen Y, Arumäe U, Lindholm D. Regulation of sympathetic neuron and neuroblastoma cell death by XIAP and its association with proteasomes in neural cells. Mol Cell Neurosci 2003; 22:308-18. [PMID: 12691733 DOI: 10.1016/s1044-7431(02)00038-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
XIAP (X chromosome-linked inhibitor of apoptosis protein) has been shown to inhibit cell death in a variety of cells. XIAP binds to active caspases, but XIAP also has a carboxy-terminal RING domain that can regulate cell death via protein degradation. Here we have studied the function of full-length and RING-deleted XIAP in mouse sympathetic neurons microinjected with expression plasmids and in neuroblastoma cells stably overexpressing these proteins. Both full-length and RING-deleted XIAP-protected sympathetic neurons against death induced by nerve growth factor (NGF) withdrawal to about the same extent. However, the two proteins were differentially localized in transfected neurons, with RING-deleted XIAP present in the cytoplasm and full-length XIAP found mostly in cytoplasmic protein aggregates, as revealed by transmission electron microscopy. The occurrence of these aggregates was blocked by lactacystin, a proteasome inhibitor. In neuroblastoma cells, RING-deleted XIAP protected against death induced by staurosporine, thapsigargin, or serum withdrawal, whereas full-length XIAP was without effect. Full-length, but not RING-deleted, XIAP was degraded and ubiquitinated in the neuroblastoma cells. The results show that the presence of the RING domain differentially affected the neuroprotective ability of XIAP in sensory neurons and neuroblastoma cells. The RING domain was essentially required for the proteasomal association of XIAP and for its ubiquitination.
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Affiliation(s)
- Li-Ying Yu
- Program of Molecular Neurobiology, Institute of Biotechnology, University of Helsinki, Finland
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