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Mo H, Kim J, Kim JY, Kim JW, Han H, Choi SH, Rim YA, Ju JH. Intranasal administration of induced pluripotent stem cell-derived cortical neural stem cell-secretome as a treatment option for Alzheimer's disease. Transl Neurodegener 2023; 12:50. [PMID: 37946307 PMCID: PMC10634159 DOI: 10.1186/s40035-023-00384-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 10/27/2023] [Indexed: 11/12/2023] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is the most common neurodegenerative disorder in the elderly, resulting in gradual destruction of cognitive abilities. Research on the development of various AD treatments is underway; however, no definitive treatment has been developed yet. Herein, we present induced pluripotent stem cell (iPSC)-derived cortical neural stem cell secretome (CNSC-SE) as a new treatment candidate for AD and explore its efficacy. METHODS We first assessed the effects of CNSC-SE treatment on neural maturation and electromagnetic signal during cortical nerve cell differentiation. Then to confirm the efficacy in vivo, CNSC-SE was administered to the 5×FAD mouse model through the nasal cavity (5 μg/g, once a week, 4 weeks). The cell-mediated effects on nerve recovery, amyloid beta (Aβ) plaque aggregation, microglial and astrocyte detection in the brain, and neuroinflammatory responses were investigated. Metabolomics analysis of iPSC-derived CNSC-SE revealed that it contained components that could exert neuro-protective effects or amplify cognitive restorative effects. RESULTS Human iPSC-derived CNSC-SE increased neuronal proliferation and dendritic structure formation in vitro. Furthermore, CNSC-SE-treated iPSC-derived cortical neurons acquired electrical network activity and action potential bursts. The 5×FAD mice treated with CNSC-SE showed memory restoration and reduced Aβ plaque accumulation. CONCLUSIONS Our findings suggest that the iPSC-derived CNSC-SE may serve as a potential, non-invasive therapeutic option for AD in reducing amyloid infiltration and restoring memory.
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Affiliation(s)
- Hyunkyung Mo
- CiSTEM Laboratory, Catholic iPSC Research Center, College of Medicine, The Catholic University of Korea, Seoul, 06591, Republic of Korea
- Department of Biomedicine and Health Science, College of Medicine, The Catholic University of Korea, Seoul, 06591, Republic of Korea
| | - Juryun Kim
- YiPSCELL, Inc, Omnibus Park, Banpo-daero 222, Seocho-gu, Seoul, 06591, Republic of Korea
| | - Jennifer Yejean Kim
- Department of Biology, Georgetown University, 3700 O St NW, Washington, DC, 20057, USA
| | - Jang Woon Kim
- CiSTEM Laboratory, Catholic iPSC Research Center, College of Medicine, The Catholic University of Korea, Seoul, 06591, Republic of Korea
| | - Heeju Han
- CiSTEM Laboratory, Catholic iPSC Research Center, College of Medicine, The Catholic University of Korea, Seoul, 06591, Republic of Korea
- Department of Biomedicine and Health Science, College of Medicine, The Catholic University of Korea, Seoul, 06591, Republic of Korea
| | - Si Hwa Choi
- CiSTEM Laboratory, Catholic iPSC Research Center, College of Medicine, The Catholic University of Korea, Seoul, 06591, Republic of Korea
- Department of Biomedicine and Health Science, College of Medicine, The Catholic University of Korea, Seoul, 06591, Republic of Korea
| | - Yeri Alice Rim
- CiSTEM Laboratory, Catholic iPSC Research Center, College of Medicine, The Catholic University of Korea, Seoul, 06591, Republic of Korea.
| | - Ji Hyeon Ju
- CiSTEM Laboratory, Catholic iPSC Research Center, College of Medicine, The Catholic University of Korea, Seoul, 06591, Republic of Korea.
- YiPSCELL, Inc, Omnibus Park, Banpo-daero 222, Seocho-gu, Seoul, 06591, Republic of Korea.
- Division of Rheumatology, Department of Internal Medicine, Seoul St. Mary's Hospital, Institute of Medical Science, College of Medicine, The Catholic University of Korea, Seoul, 06591, Republic of Korea.
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Gou M, Pan S, Tong J, Zhou Y, Han J, Xie T, Yu T, Feng W, Li Y, Chen S, Cui Y, Tian B, Tan MDS, Wang Z, Luo X, Li CSR, Zhang P, Huang J, Hong LE, Tan Y, Tian L. Effects of microRNA-181b-5p on cognitive deficits in first-episode patients with schizophrenia: Mediated by BCL-2. J Psychiatr Res 2021; 136:358-365. [PMID: 33636692 DOI: 10.1016/j.jpsychires.2021.02.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 01/31/2021] [Accepted: 02/08/2021] [Indexed: 11/26/2022]
Abstract
MicroRNA (miR)-181b-5p is considered to be involved in the pathogenesis of schizophrenia, and one of its regulatory target genes BCL-2 (B-cell lymphoma 2) is suggested to associate with cognition of schizophrenia. Cognitive deficit is a core trait of schizophrenia. However, it remains unclear whether miR-181b-5p affects cognition and its possible pathway in schizophrenia. We hypothesized that miR-181b-5p affects cognition by targeting BCL-2 mRNA and downregulating BCL-2 protein expression in schizophrenia patients. In this study, first-episode patients with schizophrenia (FEPS, n = 123) and age- and gender-matched healthy controls (HCs, n = 50) were enrolled in Chinese populations. Expression levels of miR-181b-5p and BCL-2 mRNA in peripheral whole blood were measured with quantitative real-time PCR (Q-PCR) and BCL-2 protein in plasma were measured with Enzyme Linked Immunosorbent Assay (ELISA). Psychopathology was assessed with the Positive and Negative Syndrome Scale (PANSS), cognitive function was evaluated using the MATRICS Consensus Cognitive Battery (MCCB). Peripheral blood miR-181b-5p expression level was significantly upregulated (p = 0.001) whereas BCL-2 mRNA and BCL-2 protein levels were significantly downregulated (p = 0.002, p = 0.023 respectively) in the FEPS compared with those in the HCs. The miR-181b-5p level was negatively (p = 0.005), whereas the BCL-2 mRNA level was positively (p < 0.001), correlated with working memory in FEPS. Mediating effect analysis showed that the effect of miR-181b-5p on working memory in the FEPS was exerted via targeting BCL-2 mRNA. MiR-181b-5p in combination with BCL-2 mRNA might be suggested as potential biomarker for schizophrenia in our discovery sample. In conclusion, overexpressed miR-181b-5p may affect cognitive function in patients with schizophrenia.
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Affiliation(s)
- Mengzhuang Gou
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Shujuan Pan
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Jinghui Tong
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Yanfang Zhou
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Jiarui Han
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Ting Xie
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Ting Yu
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Wei Feng
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Yanli Li
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Song Chen
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Yimin Cui
- Department of Pharmacy, Peking University First Hospital, Beijing, China
| | - Baopeng Tian
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - M D Shuping Tan
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Zhiren Wang
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Xingguang Luo
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Chiang-Shan R Li
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Ping Zhang
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - Junchao Huang
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China
| | - L Elliot Hong
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, USA
| | - Yunlong Tan
- Peking University HuiLongGuan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, China.
| | - Li Tian
- Institute of Biomedicine and Translational Medicine, Department of Physiology, Faculty of Medicine, University of Tartu, Tartu, Estonia
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Protective Effect of Biobran/MGN-3 against Sporadic Alzheimer's Disease Mouse Model: Possible Role of Oxidative Stress and Apoptotic Pathways. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:8845064. [PMID: 33574982 PMCID: PMC7857904 DOI: 10.1155/2021/8845064] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/14/2020] [Accepted: 01/03/2021] [Indexed: 12/29/2022]
Abstract
Alzheimer's disease (AD) is a debilitating and irreversible brain disease that affects an increasing number of aged individuals, mandating the development of protective nutraceuticals. Biobran/MGN-3, an arabinoxylan from rice bran, has potent antioxidant, antiaging, and immunomodulatory effects. The aim of the present study was to investigate the protective effect of Biobran against sporadic Alzheimer's disease (SAD). SAD was induced in mice via intracerebroventricular injection of streptozotocin (STZ) (3 mg/kg). STZ-treated mice were administered with Biobran for 21 days. The effects of Biobran on memory and learning were measured via the Morris water maze, novel object recognition, and Y-maze tests. Biomarkers for apoptosis, oxidative stress, and amyloidogenesis were measured using ELISA and western blot analysis. Histopathological examination was performed to confirm neuronal damage and amyloid-beta deposition. Biobran reversed the spatial memory deficit in SAD-induced mice, and it increased the expression of glutathione, reduced malondialdehyde, decreased IL-6, decreased intercellular adhesion molecule-1 (ICAM-1), and significantly increased nuclear factor erythroid 2-related factor 2 (Nrf2) and antioxidant response element (ARE). Moreover, Biobran exerted a protective effect against amyloid-beta-induced apoptosis via the suppression of both cleaved caspase-3 and the proapoptotic protein Bax and via the upregulation of the antiapoptotic protein Bcl-2. Furthermore, it reduced the expression of forkhead box class O proteins. It could be concluded from this study that Biobran may be a useful nutritional antioxidant agent for protection against SAD through its activation of the gene expression of Nrf2/ARE, which in turn modulates the apoptotic and amyloidogenic pathways.
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Khan S. IGFBP-2 Signaling in the Brain: From Brain Development to Higher Order Brain Functions. Front Endocrinol (Lausanne) 2019; 10:822. [PMID: 31824433 PMCID: PMC6883226 DOI: 10.3389/fendo.2019.00822] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 11/08/2019] [Indexed: 12/13/2022] Open
Abstract
Insulin-like growth factor-binding protein-2 (IGFBP-2) is a pleiotropic polypeptide that functions as autocrine and/or paracrine growth factors. IGFBP-2 is the most abundant of the IGFBPs in the cerebrospinal fluid (CSF), and developing brain showed the highest expression of IGFBP-2. IGFBP-2 expressed in the hippocampus, cortex, olfactory lobes, cerebellum, and amygdala. IGFBP-2 mRNA expression is seen in meninges, blood vessels, and in small cell-body neurons (interneurons) and astrocytes. The expression pattern of IGFBP-2 is often developmentally regulated and cell-specific. Biological activities of IGFBP-2 which are independent of their abilities to bind to insulin-like growth factors (IGFs) are mediated by the heparin binding domain (HBD). To execute IGF-independent functions, some IGFBPs have shown to bind with their putative receptors or to translocate inside the cells. Thus, IGFBP-2 functions can be mediated both via insulin-like growth factor receptor-1 (IGF-IR) and independent of IGF-Rs. In this review, I suggest that IGFBP-2 is not only involved in the growth, development of the brain but also with the regulation of neuronal plasticity to modulate high-level cognitive operations such as spatial learning and memory and information processing. Hence, IGFBP-2 serves as a neurotrophic factor which acts via metaplastic signaling from embryonic to adult stages.
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5
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Fröhlich M, Jaeger A, Weiss DG, Kriehuber R. Inhibition of BCL‐2 leads to increased apoptosis and delayed neuronal differentiation in human ReNcell VM cells
in vitro. Int J Dev Neurosci 2015; 48:9-17. [DOI: 10.1016/j.ijdevneu.2015.10.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 10/21/2015] [Accepted: 10/21/2015] [Indexed: 10/22/2022] Open
Affiliation(s)
- Michael Fröhlich
- University of RostockInstitute of Biological Sciences, Cell Biology and Biosystems TechnologyAlbert‐Einstein‐Straße 3D‐18051RostockGermany
| | - Alexandra Jaeger
- University of RostockInstitute of Biological Sciences, Cell Biology and Biosystems TechnologyAlbert‐Einstein‐Straße 3D‐18051RostockGermany
| | - Dieter G. Weiss
- University of RostockInstitute of Biological Sciences, Cell Biology and Biosystems TechnologyAlbert‐Einstein‐Straße 3D‐18051RostockGermany
| | - Ralf Kriehuber
- University of RostockInstitute of Biological Sciences, Cell Biology and Biosystems TechnologyAlbert‐Einstein‐Straße 3D‐18051RostockGermany
- Department of Safety and Radiation Protection, Radiation Biology UnitForschungszentrum Jülich GmbHD‐52425JülichGermany
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6
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Effects of repetitive transcranial magnetic stimulation on synaptic plasticity and apoptosis in vascular dementia rats. Behav Brain Res 2015; 281:149-55. [DOI: 10.1016/j.bbr.2014.12.037] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 12/11/2014] [Accepted: 12/15/2014] [Indexed: 11/21/2022]
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7
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Repeated cocaine administration increases B-cell leukemia/lymphoma 2 phosphorylation in the rat dorsal striatum. Neurosci Lett 2009; 468:125-9. [PMID: 19879923 DOI: 10.1016/j.neulet.2009.10.082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 10/24/2009] [Accepted: 10/26/2009] [Indexed: 12/24/2022]
Abstract
Protein phosphorylation caused by drug administration is a critical step in the regulation of behavioral alterations. This study was conducted to determine how repeated exposure to cocaine phosphorylates B-cell leukemia/lymphoma 2 (Bcl2), which may be responsible for the regulation of behavioral alterations in the rat dorsal striatum. The results revealed that repeated systemic injections of cocaine (20 mg/kg) once a day for 7 consecutive days increased the phosphorylation of Bcl2 at serine 70 (Bcl2-S70). However, this increase was reduced by the blockade of dopamine D1 receptors, group I metabotropic glutamate receptors (mGluRs), and N-methyl-D-aspartate (NMDA) receptors. In addition, elevation of behavioral locomotor activity after repeated exposure to cocaine was partially reduced by the inhibition of Bcl2. These data suggest that stimulation of dopamine D1 receptors, group I mGluRs, and NMDA receptors following repeated cocaine administration is necessary for the induction of Bcl2-S70 phosphorylation, which contributes to the expression of behavioral sensitization.
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8
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Bader Lange ML, Cenini G, Piroddi M, Abdul HM, Sultana R, Galli F, Memo M, Butterfield DA. Loss of phospholipid asymmetry and elevated brain apoptotic protein levels in subjects with amnestic mild cognitive impairment and Alzheimer disease. Neurobiol Dis 2007; 29:456-64. [PMID: 18077176 DOI: 10.1016/j.nbd.2007.11.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Revised: 09/21/2007] [Accepted: 11/05/2007] [Indexed: 11/28/2022] Open
Abstract
Oxidative stress, a hallmark of Alzheimer disease (AD), has been shown to induce lipid peroxidation and apoptosis disrupting cellular homeostasis. Normally, the aminophospholipid phosphatidylserine (PtdSer) is asymmetrically distributed on the cytosolic leaflet of the lipid bilayer. Under oxidative stress conditions, asymmetry is altered, characterized by the appearance of PtdSer on the outer leaflet, to initiate the first stages of an apoptotic process. PtdSer asymmetry is actively maintained by the ATP-dependent translocase flippase, whose function is inhibited if covalently bound by lipid peroxidation products, 4-hydroxynonenal (HNE) and acrolein, within the membrane bilayer in which they are produced. Additionally, pro-apoptotic proteins Bax and caspase-3 have been implemented in the oxidative modification of PtdSer resulting in subsequent asymmetric collapse, while anti-apoptotic protein Bcl-2 has been found to prevent this process. The current investigation focused on detection of PtdSer on the outer leaflet of the bilayer in synaptosomes from brain of subjects with AD and amnestic mild cognitive impairment (MCI), as well as expression levels of apoptosis-related proteins Bcl-2, Bax, and caspase-3. Fluorescence and Western blot analysis suggest PtdSer exposure on the outer leaflet is significantly increased in brain from subjects with MCI and AD contributing to early apoptotic elevation of pro- and anti-apoptotic proteins and finally neuronal loss. MCI is considered a possible transition point between normal cognitive aging and probable AD. Brain from subjects with MCI is reported to have increased levels of tissue oxidation; therefore, the results of this study could mark the progression of patients with MCI into AD. This study contributes to a model of apoptosis-specific oxidation of phospholipids consistent with the notion that PtdSer exposure is required for apoptotic-cell death.
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Affiliation(s)
- Miranda L Bader Lange
- Department of Chemistry, Center of Membrane Sciences, Sanders-Brown Center on Ageing, University of Kentucky, Lexington, KY 40506-0055, USA
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9
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Bezchlibnyk YB, Xu L, Wang JF, Young LT. Decreased expression of insulin-like growth factor binding protein 2 in the prefrontal cortex of subjects with bipolar disorder and its regulation by lithium treatment. Brain Res 2007; 1147:213-7. [PMID: 17395163 DOI: 10.1016/j.brainres.2007.01.147] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Revised: 10/04/2006] [Accepted: 01/11/2007] [Indexed: 11/25/2022]
Abstract
Insulin-like growth factors (IGFs) regulate cellular proliferation and death, and their bioactivity is controlled by IGF binding proteins (IGFBPs). Since IGFBP-2 is the major brain resident IGFBP, and we have demonstrated lithium-mediated changes in its mRNA and protein levels in neuronal cultures, we examined IGFBP-2 expression in prefrontal cortex postmortem brain tissue from subjects with mood disorders. We found decreased IGFBP-2 expression in bipolar disorder patients compared with controls; this was especially pronounced in subjects not treated with lithium. These results suggest a role for IGFBPs in the etiology and pharmacotherapy of mood disorders.
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Affiliation(s)
- Yarema B Bezchlibnyk
- The Vivian Rakoff Mood Disorders Lab, Centre for Addiction and Mental Health, Toronto, ON, Canada
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10
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Zeng L, Lu X, Zeng S, Lin Y, Sun Y, Zhang X, Zuo M. Dynamic changes of apoptosis and expression of Bcl-2 family members in the posthatch hippocampus of Bengalese finches. Brain Res 2006; 1107:58-69. [PMID: 16842761 DOI: 10.1016/j.brainres.2006.05.085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Revised: 05/19/2006] [Accepted: 05/26/2006] [Indexed: 10/24/2022]
Abstract
The hippocampus of songbirds plays an important role in spatial memory, and probably in song learning. Although prolonged neuronal generation and apoptosis are thought to be closely correlated with memory function, natural changes of the number of neurons and in apoptosis in the hippocampus of songbirds have not been fully investigated during development and in the adult. In the current study, we examined developmental changes in the volume and the number of neurons and apoptotic cells in the hippocampus of songbirds (Lonchura striata) from posthatch day (P5) to adulthood. Apoptotic cells were determined by Nissl staining and immunohistochemistry for cleaved caspase-3, a key apoptotic caspase executioner. The expression levels of Bcl-2 family member mRNA and protein, including Bcl-2, Bcl-xL and Bax, were also investigated. Our results indicated that: (1) the hippocampus volume significantly increased from P5 to P60, although the number of neurons remained stable in all studied stages; (2) the number of apoptotic cells was highest at P45, based either on the Nissl staining or on the immunohistochemistry for caspase-3; (3) Bcl-2 mRNA expression was high from P5 to adulthood, while Bax mRNA declined abruptly from P5 to adulthood, and Bcl-x mRNA was high after P45. Bcl-2 protein was only detected at P5 and P15, while detection of Bcl-xL and Bax proteins paralleled levels of mRNA expression. Our study provides detailed changes of apoptosis in the posthatch songbird hippocampus, suggesting an important role for caspase-3 and Bcl-2 family members in hippocampus apoptosis.
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Affiliation(s)
- Lei Zeng
- College of Life Sciences, Beijing Normal University, Beijing 100875, China
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11
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Marcol W, Kotulska K, Larysz-Brysz M, Malinowska-Kołodziej I, Mandera M, Lewin-Kowalik J. Expression of Bcl-2 and Bax protein in normal pineal gland in children and young adult. J Mol Histol 2006; 37:5-7. [PMID: 16832704 DOI: 10.1007/s10735-006-9019-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2005] [Accepted: 02/06/2006] [Indexed: 11/30/2022]
Abstract
The Bcl family contains both pro and antiapoptotic proteins participating in the regulation of neuronal cell death in several pathological conditions. However, very little is known about physiological profiles of Bcl-2/Bax expression in normal brain. In this study, we examined expression profile of Bcl-2 and Bax proteins in normal pineal gland in children. The material for analysis was obtained by biopsy of pineal parenchyma during surgery of pineal cysts. All specimens were labeled immunohistochemically and analyzed by means of confocal laser scanning microscope. We found only few Bcl-2 expressing (0.7%) and no Bax-immunopositive (0.0%) pinealocytes. Bcl-2-positive cells were mature neurons, neither young ones nor glia.
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Affiliation(s)
- Wiesław Marcol
- Department of Physiology, Medical University of Silesia, 18 Medyków, 40-752 Katowice, Poland.
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12
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Bezchlibnyk YB, Wang JF, Shao L, Young LT. Insulin-like growth factor binding protein-2 expression is decreased by lithium. Neuroreport 2006; 17:897-901. [PMID: 16738484 DOI: 10.1097/01.wnr.0000220143.37036.32] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Lithium has been shown to possess cytoprotective properties in both cellular and animal models. Moreover, previous studies indicate that lithium treatment alters the expression of insulin-like growth factor binding protein-1 (IGFBP-1), a critical modulator of insulin-like growth factor bioactivity. Given the critical roles played by insulin-like growth factors in cellular mitogenesis, differentiation, and cell death, and that IGFBP-2 is the major brain resident IGFBP, we assessed IGFBP-2 expression in primary cortical neuroncultures subsequent to lithium treatment. We report that 7 days of lithium treatment at therapeutically relevant doses attenuates the expression of IGFBP-2 mRNA and protein in a dose and time-dependent manner. Therefore, these results suggest a possible role for the insulin-like growth factor system in lithium's mechanism of action.
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Affiliation(s)
- Yarema B Bezchlibnyk
- The Vivian Rakoff Mood Disorders Laboratory, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
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13
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Kuhn HG, Biebl M, Wilhelm D, Li M, Friedlander RM, Winkler J. Increased generation of granule cells in adult Bcl-2-overexpressing mice: a role for cell death during continued hippocampal neurogenesis. Eur J Neurosci 2005; 22:1907-15. [PMID: 16262630 DOI: 10.1111/j.1460-9568.2005.04377.x] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Programmed cell death is an important mechanism during brain development in order to control neuronal cell numbers and to correctly form neuronal circuitries. Programmed cell death is also present in neurogenic regions of the adult brain, and a significant portion of the adult-born cells is eliminated during the first months of maturation. We here address the question whether overexpression of the anti-apoptotic protein Bcl-2 would improve the survival of neural progenitor cells and, as a consequence, increase neurogenesis in the adult hippocampus. Transgenic animals, which express human Bcl-2 under the neuron-specific enolase promoter (NSE-huBcl-2), show a significant reduction of apoptotic cells in the hippocampal granule cell layer to about half of the wild-type level. These apoptotic cells are almost exclusively found in the zone of hippocampal progenitor activity and frequently co-label with the neuronal progenitor marker doublecortin (DCX). The rate of adult neurogenesis is doubled in the dentate gyrus of Bcl-2-overexpressing mice as demonstrated by quantification of progenitor cells using DCX and new neurons using bromodeoxyuridine (BrdU)/neuronal nuclei antigen (NeuN) double-labelling. The effect of Bcl-2 is limited to the late phase of progenitor maturation, as proliferation and early-phase progenitor cells were not affected. The increased level of neurogenesis leads to a significantly higher total number of granule cells in the dentate gyrus. These results underline the importance of developmental cell death during neurogenesis in the adult brain.
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Affiliation(s)
- H Georg Kuhn
- Arvid Carlson Institute for Neuroscience at the Institute for Clinical Neuroscience, Sahlgrenska Academy at Göteborg University, 40530 Göteborg, Sweden.
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Lossi L, Cantile C, Tamagno I, Merighi A. Apoptosis in the mammalian CNS: Lessons from animal models. Vet J 2005; 170:52-66. [PMID: 15993789 DOI: 10.1016/j.tvjl.2004.05.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/13/2004] [Indexed: 12/30/2022]
Abstract
It is generally assumed that about half of the neurons produced during neurogenesis die before completion of maturation of the central nervous system (CNS). Neural cell death is also relevant in aging and several neurodegenerative diseases. Among the modalities by which neurons die, apoptosis has very much attracted the interest of investigators because in this type of cell death neurons are actively responsible for their own demise by switching on a number of genes and activating a series of specific intracellular pathways. This review focuses on the cellular and molecular mechanisms of apoptosis in normal and transgenic animal models related to naturally occurring neuronal death within the CNS. We will also consider some examples of apoptotic cell death in canine neuropathologies. A thorough analysis of naturally occurring neuronal death in vivo will offer a basis for parallel and future studies involving secondary neuronal loss such as those in neurodegenerative disorders, trauma or ischaemia.
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Affiliation(s)
- L Lossi
- Dipartimento di Morfofisiologia Veterinaria, University of Torino, Via Leonardo da Vinci 44, I-10095 Grugliasco, Italy.
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15
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Schwartz ML, Vaccarino F, Chacon M, Yan WL, Ment LR, Stewart WB. Chronic neonatal hypoxia leads to long term decreases in the volume and cell number of the rat cerebral cortex. Semin Perinatol 2004; 28:379-88. [PMID: 15693394 DOI: 10.1053/j.semperi.2004.10.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Preterm birth results in significant neurodevelopmental disability. The neonatal rodent model of chronic sublethal hypoxia faithfully mimics the effect of preterm birth on the developing brain. We employed this model to test the hypothesis that the hypoxia that accompanies preterm birth results in inappropriate signaling of apoptotic mechanisms in developing brain. We performed cortical cell counts, determinations of neuronal size and Western analyses of the apoptosis related proteins, Bcl-2 and Bax, in rat pups who were raised in chronic hypoxia (FiO2 9.5%) beginning on postnatal day 3 (P3) and extending for either 10 (P13) or 30 (P33) days. A third group of animals was exposed to 30 days of hypoxia followed by an additional 30 days in a normoxic environment (P63) to assess the potential for recovery from the initial effects of hypoxia. Age matched control pups were raised in room air throughout the experimental time period. Assessment of cortical cell number revealed a 25% reduction (P < 0.01) in total cell number following 30 days of hypoxic rearing. Glia were significantly reduced by 34% and 41% after 10 and 30 days of hypoxia, respectively, while neuron numbers were only significantly reduced (14%) after 30 days of hypoxia. Animals exposed to a hypoxic environment for 30 days followed by 30 days in a normoxic environment revealed some recovery of glial cell numbers, but no significant recovery of neuronal cell numbers. Measurement of cell size at both P13 and P33 revealed that neurons of layer III were significantly smaller in cross-sectional area in hypoxic compared with control rats (P < 0.01). However, no significant difference was noted in neuronal size following 30 days of normoxic recovery. Western blot analyses of Bcl-2 and Bax protein levels demonstrated a ratio favorable to Bax at multiple time points during the period of hypoxic exposure. These data suggest that chronic exposure to hypoxia during the perinatal period alters the production and maintenance of glial and neuronal cells and that glia and neurons demonstrate differential patterns of vulnerability and recovery following subsequent periods of normoxic exposure. It is hypothesized that the mechanisms responsible for these alterations in cortical cell number may depend on the state of differentiation of the different cell types at the time of hypoxic exposure.
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Affiliation(s)
- Michael L Schwartz
- Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06510, USA.
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16
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Bai O, Zhang H, Li XM. Antipsychotic drugs clozapine and olanzapine upregulate bcl-2 mRNA and protein in rat frontal cortex and hippocampus. Brain Res 2004; 1010:81-6. [PMID: 15126120 DOI: 10.1016/j.brainres.2004.02.064] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/23/2004] [Indexed: 11/16/2022]
Abstract
To investigate whether atypical antipsychotic drugs exert an effect on the neuroprotective protein Bcl-2, rats were chronically treated with clozapine or olanzapine for 28 days. The expression of bcl-2 mRNA and Bcl-2 protein was determined, respectively, by in situ hybridization in tissue sections and Western blot on tissue samples from rat frontal cortex and hippocampus. The bcl-2 mRNA positive cells were increased in these regions after drug treatments, and quantitative analysis revealed that the upregulation of bcl-2 mRNA and Bcl-2 protein is significantly greater than in vehicle control (p<0.05 or p<0.01). It is demonstrated that neuroprotective protein Bcl-2 is involved in the action of atypical antipsychotic drugs, and might represent a neuroprotective mechanism of these drugs.
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Affiliation(s)
- Ou Bai
- Neuropsychiatry Research Unit, Department of Psychiatry, University of Saskatchewan, A114 Medical Research Building, 103 Wiggins Road, Saskatoon, SK, Canada S7N 5E4
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17
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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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18
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Lossi L, Merighi A. In vivo cellular and molecular mechanisms of neuronal apoptosis in the mammalian CNS. Prog Neurobiol 2003; 69:287-312. [PMID: 12787572 DOI: 10.1016/s0301-0082(03)00051-0] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Apoptosis has been recognized to be an essential process during neural development. It is generally assumed that about half of the neurons produced during neurogenesis die before completion of the central nervous system (CNS) maturation, and this process affects nearly all classes of neurons. In this review, we discuss the experimental data in vivo on naturally occurring neuronal death in normal, transgenic and mutant animals, with special attention to the cerebellum as a study model. The emerging picture is that of a dual wave of apoptotic cell death affecting central neurons at different stages of their life. The first wave consists of an early neuronal death of proliferating precursors and young postmitotic neuroblasts, and appears to be closely linked to cell cycle regulation. The second wave affects postmitotic neurons at later stages, and is much better understood in functional terms, mainly on the basis of the neurotrophic concept in its broader definition. The molecular machinery of late apoptotic death of postmitotic neurons more commonly follows the mitochondrial pathway of intracellular signal transduction, but the death receptor pathway may also be involved.Undoubtedly, analysis of naturally occurring neuronal death (NOND) in vivo will offer a basis for parallel and future studies aiming to elucidate the mechanisms of pathologic neuronal loss occurring as the result of conditions such as neurodegenerative disorders, trauma or ischemia.
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Affiliation(s)
- L Lossi
- Department of Veterinary Morphophysiology, University of Torino, Via Leonardo da Vinci 44, I-10095 (TO), Grugliasco, Italy.
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19
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Heaton MB, Madorsky I, Paiva M, Mayer J. Influence of ethanol on neonatal cerebellum of BDNF gene-deleted animals: analyses of effects on Purkinje cells, apoptosis-related proteins, and endogenous antioxidants. JOURNAL OF NEUROBIOLOGY 2002; 51:160-76. [PMID: 11932957 DOI: 10.1002/neu.10051] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The sensitivity of the developing central nervous system (CNS) to the deleterious effects of ethanol has been well documented, with exposure leading to a wide array of CNS abnormalities. Certain CNS regions are susceptible to ethanol during well-defined critical periods. In the neonatal rodent cerebellum, a profound loss of Purkinje cells is found when ethanol is administered early in the postnatal period [on postnatal days 4 or 5 (P4-5)], while this neuronal population is much less vulnerable to similar ethanol insult slightly later in the postnatal period (P7-9). Prior studies have shown that neurotrophic factors (NTFs) can be altered by ethanol exposure, and both in vitro and in vivo studies have provided evidence that such substances have the potential to protect against ethanol neurotoxicity. In the present study, it was hypothesized that depletion of an NTF shown to be important to cerebellar development would exacerbate ethanol-related effects within this region, when administration was confined to a normally ethanol-resistant ontogenetic period. For this study, brain-derived neurotrophic factor (BDNF) gene-deleted ("knockout") and wild-type mice were exposed to ethanol via vapor inhalation or to control conditions during the normally ethanol-resistant period (P7 and P8). Two hours after termination of exposure on P8, analyses were made of body weight, crown-rump length, and brain weight. In subsequent investigations, the number and density of Purkinje cells and the volume of cerebellar lobule I were determined, and the expression of anti- and pro-apoptotic proteins and the activities of endogenous antioxidants were assessed. It was found that the BDNF knockouts were significantly smaller than the wild-type animals, with smaller brain weights. Purkinje cell number and density was reduced in ethanol-treated knockout, but not wild-type animals, and the volume of lobule I was significantly decreased in the gene-deleted animals compared to wild-types, but was not further affected by ethanol treatment. The loss of Purkinje cells in the BDNF knockouts was accompanied by decreases in anti-apoptotic Bcl-xl and in phosphorylated (and hence inactivated) pro-apoptotic Bad, and reduced activity of the antioxidant glutathione reductase, while the antioxidant catalase was increased by ethanol treatment in this genotype. In the wild-type animals, anti-apoptotic Bcl-2 was decreased by ethanol treatment, but the pro-apoptotic c-Jun N-terminal kinase (JNK) was markedly diminished by ethanol exposure, while the activity of the protective antioxidant superoxide dismutase (SOD) was significantly enhanced. These results suggest that neurotrophic factors have the capacity to protect against ethanol neurotoxicity, perhaps by regulation of expression of molecules critical to neuronal survival such as elements of the apoptosis cascade and protective antioxidants.
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Affiliation(s)
- Marieta Barrow Heaton
- Department of Neuroscience, McKnight Brain Institute, University of Florida College of Medicine, Box 100244, Gainesville, FL 32610-0244, USA.
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20
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Vinet J, Bernier PJ, Parent A. Bcl-2 expression in thalamus, brainstem, cerebellum and visual cortex of adult primate. Neurosci Res 2002; 42:269-77. [PMID: 11985879 DOI: 10.1016/s0168-0102(02)00004-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Due to the functional importance of Bcl-2, which acts as an anti-apoptotic protein that also affects neural differentiation and adult neurogenesis, we undertook a detailed immunohistochemical study of the distribution of this protein in the brain of squirrel monkeys. The present study describes findings obtained at thalamic, brainstem, cerebellum and visual cortex levels, and the data are compared with our previous results gathered in the same species. At thalamic level, Bcl-2-positive neurons occur in anterior, rostral intralaminar, midline and lateral habenular nuclei. The protein is also expressed in several structures associated with the ventricular system, including the subventricular zone (SVZ), the subcommissural organ, and the periventricular grey at rostral and caudal tips of the fourth ventricle. At brainstem and cerebellar levels, Bcl-2-positive neurons occur in the dorsal raphe nucleus, inferior olivary complex, and in molecular and granular layers of the cerebellum. Finally, neurons of layer IV of the striate cortex display a very strong Bcl-2 immunoreactivity that contrasts with the poor labeling of neurons in adjacent parastriate and peristriate cortices. These finding suggests that Bcl-2 plays a role in the plasticity and structural maintenance of various structures in the primate brain and indicate that the mitotically active SVZ might be more extended along the rostrocaudal axis in primates than in rodents.
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Affiliation(s)
- Jonathan Vinet
- Centre de Recherche Université Laval Robert-Giffard, 2601, Chemin de la Canardière, Local F-6500, Quebec, G1J 2G3, Beauport, Canada
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21
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Krajewska M, Mai JK, Zapata JM, Ashwell KWS, Schendel SL, Reed JC, Krajewski S. Dynamics of expression of apoptosis-regulatory proteins Bid, Bcl-2, Bcl-X, Bax and Bak during development of murine nervous system. Cell Death Differ 2002; 9:145-57. [PMID: 11840165 DOI: 10.1038/sj.cdd.4400934] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2000] [Revised: 04/20/2001] [Accepted: 07/10/2001] [Indexed: 11/09/2022] Open
Abstract
We have used immunohistochemistry and immunoblotting to examine the expression of Bid and four other Bcl-2 family proteins (Bcl-2, Bcl-X, Bax and Bak) in the developing and adult murine central nervous system (CNS). Bid protein is widespread in embryonic and postnatal brain, and its expression is maintained at a high level late into the adulthood. Bid is expressed both in the germ disc, early neural tube, proliferating stem cells of ventricular zones, and in postmitotic, differentiated neurons of the developing central and peripheral nervous system. As the differentiation proceeds, the neurons express higher levels of Bid than the stem cells of the paraventricular zone. Both in embryonic and postnatal life, Bid protein is present in the most vital regions of brain, such as the limbic system, basal ganglia, mesencephalic tectum, Purkinje cells in cerebellum, and the ventral columns of spinal cord. The p15 cleaved form of Bid was detectable in the brain specimens at fetal stages of development, consistent with caspase-mediated activation of this pro-apoptotic Bcl-2 family protein. Among the Bcl-2 family proteins only Bid and Bcl-XL continue to be expressed at high levels in the adult brain.
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Affiliation(s)
- M Krajewska
- The Burnham Institute, 10901 N Torrey Pines Road, La Jolla, CA 92037, USA
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22
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Abstract
Female rodents producing endogenous estrogens are protected from stroke damage in comparison with male counterparts. This natural protection is lost after ovariectomy or reproductive senescence. The aim of this study is to determine whether estrogen reduces early neuronal injury and cell loss after ischemia by increasing the expression of Bcl-2. Male, intact female, ovariectomized, and estrogen-repleted ovariectomized rats were subjected to middle cerebral artery occlusion, and 22 hr later the level and localization of Bcl-2 mRNA and protein were determined. The levels of post-ischemic bcl-2 mRNA and protein were increased exclusively in neurons within the peri-infarct region. Intact females and estrogen-treated castrates demonstrated increased bcl-2 mRNA and protein expression compared with males and estrogen-deficient females, accompanied by a decrease in infarct size. To test the hypothesis that the neuroprotective mechanism of estrogen functions via Bcl-2, we compared ischemic outcome in male, female, and ovariectomized wild-type mice and mice overexpressing Bcl-2 exclusively in neurons. Wild-type female mice sustained smaller infarcts compared with males. Bcl-2 overexpression reduced infarct size in males, but provided no added protection in the female. Moreover, ovariectomy exacerbated infarction in wild-type females, but had no effect in Bcl-2 overexpressors. These data indicate that overexpression of Bcl-2 simulates the protection against ischemic injury conferred by endogenous female sex steroids. We concluded that estrogen rescues neurons after focal cerebral ischemia by increasing the level of Bcl-2 in peri-infarct regions and that estrogen-induced bcl-2 gene expression is an important downstream component of neuronal protection in female stroke.
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23
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Wang Z, Li H, Chi F, Li H, Shen Y. Transient Bax-protein immunoreactivity prior to apoptosis of spiral ganglion neurons in the postnatal rat. Acta Otolaryngol 2001; 121:777-80. [PMID: 11718238 DOI: 10.1080/00016480152602195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The apoptosis occurring in the postnatal developing spiral ganglion cells (SGCs) and the concomitant change in Bax-protein immunoreactivity were investigated in rats at postnatal days (P) 1, 3, 5, 7, 10 and 14, and also in adult rats. In P5 and P7 rats, some neurons showed structural features of apoptosis, including cell shrinkage, condensed chromatin around the margin of the nucleus and phagocytosis of apoptotic bodies by satellite cells. The percentage of Bax-protein-positive neurons in the spiral ganglion was significantly higher in P1, P3, P5, and P7 rats compared with adult rats. Our results confirm the occurrence of neuronal cell apoptosis in the spiral ganglion at the end of the first postnatal week, and demonstrate the transient change in Bax-protein immunoreactivity prior to neuronal cell apoptosis. Thus, we speculate that the transient change in Bax protein could be involved in neuronal cell apoptosis of the postnatal developing SGCs of rats.
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Affiliation(s)
- Z Wang
- Department of Otolaryngology, EENT Hospital, Shanghai Medical University, People's Republic of China.
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24
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Daadi MM, Saporta S, Willing AE, Zigova T, McGrogan MP, Sanberg PR. In vitro induction and in vivo expression of bcl-2 in the hNT neurons. Brain Res Bull 2001; 56:147-52. [PMID: 11704352 DOI: 10.1016/s0361-9230(01)00621-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bcl-2 encodes membrane-associated proteins that suppress programmed cell death in cells of various origins. Compelling evidence suggests that bcl-2 is also involved in neuronal differentiation and axonal regeneration. The human Neuro-Teratocarcinoma (hNT) neurons constitute a terminally differentiated human neuronal cell line that is derived from the Ntera-2/clone D1 (NT2) precursors upon retinoic acid (RA) treatment. After transplantation into the central nervous system (CNS), the hNT neurons survive, engraft, maintain their neuronal identity, and extend long neurite outgrowth. We were particularly interested in the intracellular determinants that confer these post-transplant characteristics to the hNT neurons. Thus, we asked whether the hNT neurons express bcl-2 after transplantation into the rat striatum and if RA induction of the neuronal lineage is mediated by bcl-2. The grafted hNT neurons were first identified using three different antibodies that recognize human-specific epitopes, anti-hMit, anti-hNuc, and NuMA. After a 1-month post-transplant survival time, NuMA immunostaining revealed that 12% of the hNT neurons survived the transplantation. These neurons extended long neuritic processes within the striatum, as demonstrated using the human-specific antibody against the midsize neurofilament subunit HO14. Importantly, we found that 85% of the implanted hNT neurons expressed bcl-2 and that the in vitro induction of the neuronal lineage from the NT2 precursors with RA resulted in an upregulation of bcl-2 expression. Together, these data suggest that the differentiation of the hNT neurons to a neuronal lineage could be mediated at least partially by bcl-2.
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Affiliation(s)
- M M Daadi
- Center for Aging and Brain Repair, University of South Florida College of Medicine, Tampa, Florida, USA.
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25
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Rolletschek A, Chang H, Guan K, Czyz J, Meyer M, Wobus AM. Differentiation of embryonic stem cell-derived dopaminergic neurons is enhanced by survival-promoting factors. Mech Dev 2001; 105:93-104. [PMID: 11429285 DOI: 10.1016/s0925-4773(01)00385-9] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Here, we describe the generation of viable and dopamine-producing neurons derived from pluripotent mouse embryonic stem cells. Neurotrophic factors in combination with survival-promoting factors, such as interleukin-1beta, glial cell line-derived neurotrophic factor, neurturin, transforming growth factor-beta(3) and dibutyryl-cyclic AMP, significantly enhanced Nurr1 and tyrosine hydroxylase (TH) mRNA levels, whereas En-1, mash-1 and dopamine-2-receptor mRNA levels were not upregulated. In parallel, mRNA levels of the anti-apoptotic gene bcl-2 were found to be upregulated at terminal stages. Double immunofluorescence analysis revealed increased numbers of TH- and dopamine transporter-, but not gamma-aminobutyric acid- and serotonin-positive neurons in relation to synaptophysin-labeled cells by survival-promoting factors. Moreover, high-performance liquid chromatography analysis showed detectable levels of intracellular dopamine. We conclude that survival-promoting factors enhance differentiation, survival and maintenance of dopaminergic neurons derived from embryonic stem cells.
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Affiliation(s)
- A Rolletschek
- 'In vitro Differentiation' Group, Institute of Plant Genetics and Crop Plant Research, Corrensstrasse 3, D-06466, Gatersleben, Germany
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26
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Takahashi J, Fukuda T, Tanaka J, Minamitani M, Onouchi K, Makioka A. Bax-induced apoptosis not demonstrated in the congenital toxoplasmosis in mice. Brain Dev 2001; 23:50-3. [PMID: 11226731 DOI: 10.1016/s0387-7604(01)00179-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A prominent neuropathological change observed in a murine model of congenital toxoplasmosis is cerebral cortical hypoplasia. In the early embryonic life of toxoplasmosis mice, the number of apoptotic cell observed in cerebral cortex is increased, indicating that increased number of apoptotic cells might relate to the pathogenetic mechanism of the cortical hypoplasia. Immunohistochemical expression of apoptosis-related factors, Bcl-2 and Bax has been studied in fetal murine brains infected with toxoplasma and in controls. Paraffin sections of the fetal brains on embryonic day (ED) 10, 12, 14, 16 and 18 were applied for the immunostains of Bcl-2 and Bax. Totally, 47 experimental animals (ED10: n=8, ED12: n=6, ED14: n=12, ED16: n=6, ED18: n=15) and 48 control animals (ED10: n=6, ED12: n=8, ED14: n=9, ED16: n=9, ED18: n=16) were examined. Bcl-2 positive cells were detected on ED10, whereas Bax positive cells appeared on ED14. No difference of Bcl-2 and Bax expression between toxoplasmosis and control groups was detected, suggesting that there is no clear relation between Bax-induced apoptosis and cortical dysplasia in congenital toxoplasmosis.
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MESH Headings
- Animals
- Apoptosis/physiology
- Body Patterning/physiology
- Cerebral Cortex/abnormalities
- Cerebral Cortex/pathology
- Cerebral Cortex/physiopathology
- Female
- Fetus
- Mice
- Mice, Inbred C57BL
- Nervous System Malformations/parasitology
- Nervous System Malformations/pathology
- Nervous System Malformations/physiopathology
- Neurons/metabolism
- Neurons/pathology
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins c-bcl-2/metabolism
- Toxoplasma/pathogenicity
- Toxoplasma/physiology
- Toxoplasmosis, Animal/metabolism
- Toxoplasmosis, Animal/pathology
- Toxoplasmosis, Animal/physiopathology
- Toxoplasmosis, Cerebral/metabolism
- Toxoplasmosis, Cerebral/pathology
- Toxoplasmosis, Cerebral/physiopathology
- Toxoplasmosis, Congenital/metabolism
- Toxoplasmosis, Congenital/pathology
- Toxoplasmosis, Congenital/physiopathology
- bcl-2-Associated X Protein
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Affiliation(s)
- J Takahashi
- Division of Neuropathology, Jikei University School of Medicine, 3-25-8, Nishi-shim bashi, Minato-Ku, 105-8461, Tokyo, Japan.
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27
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Shin DH, Lee HW, Jeon GS, Lee HY, Lee KH, Cho SS. Constitutive expression of c-myb mRNA in the adult rat brain. Brain Res 2001; 892:203-7. [PMID: 11172765 DOI: 10.1016/s0006-8993(00)03300-x] [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: 11/26/2022]
Abstract
In this study, we demonstrated the c-myb mRNA expression in the adult rat brain using an in situ hybridization technique. We found c-myb mRNA signals in the various regions of the forebrain and midbrain including the cerebral cortex, thalamus, hippocampus, hypothalamus, superior and inferior colliculi and central gray. In the cerebellum, a diffuse signal was found in the granular layer while some positive cells were detected in the molecular layer as well. In addition, a number of cells showed intense signals in many nuclei of the medulla oblongata. The constitutive expression of c-myb mRNA in the different kinds of neural cells suggests that this gene might be involved in the normal function of these neurons.
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Affiliation(s)
- D H Shin
- Department of Anatomy, Dankook University College of Medicine, Chonan, South Korea
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28
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Wang S, Rosengren L, Hamberger A, Haglid K. Antisense inhibition of BCL-2 expression induces retinoic acid-mediated cell death during differentiation of human NT2N neurons. J Neurochem 2001; 76:1089-98. [PMID: 11181829 DOI: 10.1046/j.1471-4159.2001.00142.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Changes in expression of the proto-oncogene Bcl-2 are well known in the developing brain, with a high expression level in young post-mitotic neurons that are beginning the outgrowth of processes. The physiological significance of the Bcl-2 up-regulation in these neurons is not fully understood. We used a differentiation model for human CNS neurons to study the expression and function of Bcl-2. NT2/D1 human neuronal precursor cells differentiated into a neuronal phenotype in the presence of 10 microM retinoic acid for 3-5 weeks. This concentration of retinoic acid was not toxic to undifferentiated NT2/D1 cells but was sufficient to up-regulate the BCL-2 protein in 6 days. The BCL-2 levels increased further after 3 weeks, i.e. when the cells started to show neuronal morphology. Inhibition of the accumulation of endogenous BCL-2 with vectors expressing the antisense mRNA of Bcl-2 caused extensive apoptosis after 3 weeks of the retinoic acid treatment. The loss of neuron-like cells from differentiating cultures indicated that the dead cells were those committed to neuronal differentiation. Death was related to the presence of retinoic acid since withdrawal of retinoic acid after 16 days of treatment dramatically increased cell surviving. The ability of BCL-2 to prevent retinoic acid-induced cell death was also confirmed in undifferentiated NT2/D1 cells that were transfected with a vector containing Bcl-2 cDNA in sense orientation and exposed to toxic doses (40-80 microM) of retinoic acid. Furthermore, down-regulation of BCL-2 levels by an antisense oligonucleotide in neuronally differentiated NT2/D1 cells increased their susceptibility to retinoic acid-induced apoptosis. These results indicate that one function of the up-regulation of endogenous BCL-2 during neuronal differentiation is to regulate the sensitivity of young post-mitotic neurons to retinoic acid-mediated apoptosis.
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Affiliation(s)
- S Wang
- Department of Anatomy and Cell Biology, Göteborg University, Sweden.
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29
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Abstract
The ability of peripheral nervous system (PNS) but not central nervous system (CNS) neurons to regenerate their axons is a striking peculiarity of higher vertebrates. Much research has focused on the inhibitory signals produced by CNS glia that thwart regenerating axons. Less attention has been paid to the injury-induced loss of trophic stimuli needed to promote the survival and regeneration of axotomized neurons. Could differences in the mechanisms that control CNS and PNS neuronal survival and growth also contribute to the disparity in regenerative capacity? Here we review recent studies concerning the nature of the signals necessary to promote neuronal survival and growth, with an emphasis on their significance to regeneration after CNS injury.
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Affiliation(s)
- J L Goldberg
- Department of Neurobiology, Stanford University School of Medicine, California 94305-5125, USA.
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30
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Yamada M, Mizuguchi M, Nishimaki K, Takashima S, Ikeda K, Ohta S, Takahashi H. Localization of Bcl-xbeta in the developing and adult rat central nervous system. J Neurosci Res 2000; 60:468-77. [PMID: 10797549 DOI: 10.1002/(sici)1097-4547(20000515)60:4<468::aid-jnr5>3.0.co;2-v] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
bcl-xbeta is a novel apoptosis-regulating member of the bcl-x family that has recently been isolated from rats and mice. To explore the functional role of Bcl-xbeta, we raised a monoclonal antibody against rat Bcl-xbeta protein and investigated the cellular localization of the molecule in the rat CNS. Immunohistochemistry revealed that, in the fetal and neonatal stages, Bcl-xbeta was intensively and widely expressed in the CNS. Many neurons in the diencephalon and brain stem showed intense cytoplasmic labeling. The immunoreactivity decreased during the postnatal development and reached to the level of adulthood by P14. In the adult brain and spinal cord, labeling was restricted to specific types of neurons and distributed throughout their somata and dendrites. Weak immunoreactivity was present in many CNS regions such as the cerebral cortex, hippocampal dentate gyrus, caudate-putamen, globus pallidus, thalamus, locus ceruleus, pontine nuclei, inferior olive, reticular formation, cerebellar cortex and spinal anterior horn. Amygdaloid nuclei and hippocampal CA1 to CA3 sectors showed restricted expression of Bcl-xbeta in a subset of neurons. Neuronal labeling was almost undetectable in several regions, including the piriform cortex, hypothalamus, posterior column nuclei and spinal posterior horn. These results suggest that Bcl-xbeta plays an important role throughout the CNS in developing stage and may regulate the apoptosis of postnatal CNS neurons.
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Affiliation(s)
- M Yamada
- Department of Pathology, Brain Research Institute, Niigata University, Asahimachi-1, Niigata, Japan.
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31
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Almeida OF, Condé GL, Crochemore C, Demeneix BA, Fischer D, Hassan AH, Meyer M, Holsboer F, Michaelidis TM. Subtle shifts in the ratio between pro- and antiapoptotic molecules after activation of corticosteroid receptors decide neuronal fate. FASEB J 2000; 14:779-90. [PMID: 10744634 DOI: 10.1096/fasebj.14.5.779] [Citation(s) in RCA: 231] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Glucocorticoid receptor (GR) activation induces apoptosis of granule cells in the hippocampus. In contrast, neuroprotection is seen after mineralocorticoid receptor (MR) activation. To date there is no in vivo evidence for direct interactions between corticosteroids and any of the key regulatory molecules of programmed cell death. In this report, we show that the opposing actions of MR and GR on neuronal survival result from their ability to differentially influence the expression of members of the bcl-2 gene family; specifically, in the rat hippocampus, activation of GR induces cell death by increasing the ratio of the proapoptotic molecule Bax relative to the antiapoptotic molecules Bcl-2 or Bcl-x(L); the opposite effect is observed after stimulation of MR. The same results were obtained in both young and aged animals; however, older subjects (which were more susceptible to GR-mediated apoptosis) tended to express the antiapoptotic genes more robustly. Using a loss-of-function mouse model, we corroborated the observations made in the rat, demonstrating Bax to be essential in the GR-mediated cell death-signaling cascade. In addition, we show that GR activation increases and MR activation decreases levels of the tumor suppressor protein p53 (a direct transcriptional regulator of bax and bcl-2 genes), thus providing new information on the early genetic events linking corticosteroid receptors with apoptosis in the nervous system.
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Affiliation(s)
- O F Almeida
- Department of Neuroendocrinology, Max Planck Institute of Psychiatry, 80804 Munich, Germany.
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32
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Cheema ZF, West JR, Miranda RC. Ethanol Induces Fas/Apo [Apoptosis]-1 mRNA and Cell Suicide in the Developing Cerebral Cortex. Alcohol Clin Exp Res 2000. [DOI: 10.1111/j.1530-0277.2000.tb02022.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Wong CC, Poon WH, Tsim TY, Wong EY, Leung MS. Gene expressions during the development and sexual differentiation of the olfactory bulb in rats. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2000; 119:187-94. [PMID: 10675768 DOI: 10.1016/s0165-3806(99)00173-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In this study, expressions of cell-cycle-related genes: p53, retinoblastoma (Rb), p21, bcl-2(alpha), bcl-2(beta); protooncogene c-ski; glial cell marker protein gene S100beta; neurotransmitter gene, substance P and sexual-differentiation-related genes, androgen receptor (AR) and estrogen receptor beta (ER(beta)), are studied in the olfactory bulb of groups of both six female and six male rats at the ages of 3, 10, 20 and 40 days. Expressions of housekeeping genes such as beta-actin, cyclophilin and proliferating cell nuclear antigens (PCNA) are determined using reverse transcription polymerase chain reaction (RT-PCR) for the correction of unequal amount of cDNA added into the samples. Using labeled 32P-dCTP and Phosphorimager technology, relative abundance of radioactivities of the PCR products is obtained by dividing the radioactivity of each individual sample by the corresponding radioactivities of different housekeeping genes. Data evaluated by Two-way ANOVA indicate that only the bcl-2(alpha) gene expression is affected significantly by age, sex and their interactions no matter which of the three housekeeping genes is used for correction. When beta-actin was used for corrections, effects of age but not sex were found in the expressions of p53, Rb, p21, AR, ER(beta), substance P and S100beta genes, but not in bcl-2(beta), c-ski, cyclophilin and PCNA genes. While cyclophilin was used for corrections, only the p53, Rb, AR, ER(beta), substance P and S100beta but not the bcl-2(beta), p21, c-ski, PCNA and beta-actin genes are affected by age. They are all not influenced by sex of the animals. Only the AR, ER(beta) and S100beta genes are age-dependent when PCNA was used for the correction. The other gene expressions are not altered by sex, while the interactions of age and sex were found to be significantly affecting the bcl-2(beta) gene expression. Conclusively, developmental changes of the p53, Rb, AR, ER(beta), substance P and S100beta genes expressions are quite evidenced while only the bcl-2(alpha) gene seems to change significantly during the sexual differentiation of olfactory bulb in rats.
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Affiliation(s)
- C C Wong
- Department of Physiology, The Chinese University of Hong Kong, Shatin, NT, Hongkong, China.
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Jarskog LF, Gilmore JH. Developmental expression of Bcl-2 protein in human cortex. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2000; 119:225-30. [PMID: 10675772 DOI: 10.1016/s0165-3806(99)00176-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Apoptosis is essential for normal human neurodevelopment and is increasingly recognized for its role in various neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Bcl-2 is a 26 kDa membrane-associated protein known to protect neurons against apoptosis. Interestingly, Bcl-2 protein levels are altered in certain neurodegenerative disorders that reveal increased apoptosis. However, little is known about the normal expression of Bcl-2 protein in human brain. Bcl-2 protein levels were determined by ELISA and semiquantitative Western Blotting in the frontal cortex of 20 human post-mortem brains, separated into three groups: six infants (age: 0.83+/-1.0 years, mean+/-S.D.), five adolescents (age: 17.4+/-1.7 years), and nine adults (age: 41.0+/-9.6 years). All subjects died of non-CNS related illness and had no history of psychiatric illness. Bcl-2 increased significantly across the age groups in the ELISA (p=0.0058) and the Western Blot (p=0.002) experiments. The ELISA demonstrated significant differences in Bcl-2 levels between infant and adolescent cortex (p<0.05), and between infant and adult cortex (p<0.01) using a post-hoc Tukey's multiple comparison test. The Western blots demonstrated a similar significant increase in Bcl-2 between infant and adult cortex (p<0. 01). A secondary analysis showed significant correlation between individual ages and Bcl-2 levels (r(2)=0.4933, p=0.0006). This study demonstrates that Bcl-2 protein expression in human cortex is developmentally regulated and supports the hypothesis that Bcl-2 is involved in normal aging.
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Affiliation(s)
- L F Jarskog
- Department of Psychiatry, C.B. #7160, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7160, USA.
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35
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Baker NL, Carlo Russo V, Bernard O, D'Ercole AJ, Werther GA. Interactions between bcl-2 and the IGF system control apoptosis in the developing mouse brain. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1999; 118:109-18. [PMID: 10611509 DOI: 10.1016/s0165-3806(99)00136-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The IGF system and the pro-survival Bcl-2 proteins protect cells from apoptosis and play a key role in brain development. In order to examine a possible relationship between these two potent anti-apoptotic systems, we utilised two transgenic mice models overexpressing either Bcl-2 or IGF-I proteins in olfactory bulb (OB) or cerebellar neurons, respectively. We have demonstrated that while the organization of the defined layers of the OB from the bcl-2 transgenic and wildtype mice cultured in serum free medium (SF) was similarly poor, the mitral cell layer from the transgenic mice was expanded and their neurons were well preserved. Addition of IGF-I improved the definition of the layers normally present within the OB, in both wildtype and bcl-2 transgenic mice, and restored wildtype mitral cell layer structure and neuronal survival similar to that in bcl-2 mice, whose mitral cell survival was not further enhanced by IGF-I. Immunoreactivity for IGF-I and IGFBP-2 was markedly increased in these Bcl-2-expressing mitral cells compared to wildtype mice. In newborn IGF-I transgenic mice, cerebellar Purkinje cells overexpressing IGF-I showed markedly increased immunoreactivity for Bcl-2 and IGFBP-2. These studies indicate that in the developing brain IGF-I modulates expression of its major binding protein IGFBP-2, as well as the Bcl-2 protein. In addition apoptosis caused by culturing OBs in SF medium, is inhibited by expression of Bcl-2 in the mitral neurons and is associated with enhanced expression of the IGF system, including IGF-I and IGFBP-2. The later may thus play a role in IGF targeting. This complex interaction between the two potent anti-apoptotic systems is likely to provide a robust system of cell protection during brain development and repair.
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Affiliation(s)
- N L Baker
- Centre for Hormone Research, Royal Children's Hospital, Flemington Road, Parkville, Victoria, Australia
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López E, Pozas E, Rivera R, Ferrer I. Bcl-2, Bax and Bcl-x expression following kainic acid administration at convulsant doses in the rat. Neuroscience 1999; 91:1461-70. [PMID: 10391451 DOI: 10.1016/s0306-4522(98)00704-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Neuronal death was produced in the CA1 and CA3 areas of the hippocampus, amygdala, and piriform and entorhinal cortices after intraperitioneal administration of kainic acid at convulsant doses to adult rats. To assess the involvement of members of the Bcl-2 family in cell death or survival, immunohistochemistry, western and northern blotting to Bcl-2, Bcl-x and Bax, and in situ hybridization to Bax were examined at different time-points after kainic acid treatment. Members of the Bcl-2 family were expressed in the cytoplasm of pyramidal neurons in the hippocampus, and in a subset of neurons of the piriform and the entorhinal cortices, amygdala and neocortex in the normal adult brain. Dying neurons in the pyramidal cell layer of CA1 and CA3 areas, entorhinal and piriform cortices, and amygdala also expressed Bcl-2, Bax and Bcl-x following excitotoxicity, although many dying cells did not. In addition, a number of cells in the affected areas showed Bax immunoreactivity in their nuclei at 24-48 h following kainic acid administration, thus indicating Bax nuclear translocation in a subset of dying cells. Western blots disclosed no modifications in the intensity of the bands corresponding to Bcl-2, Bcl-x and Bax, between control and kainic acid-treated rats. No modifications in the intensity of the bcl-2 messenger RNA band on northern blots was observed in kainic acid-treated rats. However, a progressive increase in the intensity of the bax messenger RNA band was found in kainic acid-treated rats at 6 h, 12 h and 24 h following kainic acid administration. Interestingly, a slight increase in Bax immunoreactivity was observed in the cytoplasm of neurons of the dentate gyrus at 24-48 h, a feature which matches the increase of bax messenger RNA in the same area, as shown by in situ hybridization at 12-24 h following kainic acid injection. The present results suggest that cell death or survival does not correlate with modifications of Bcl-2, Bax and Bcl-x protein, and messenger RNA expression, but rather that kainic acid excitotoxicity is associated with Bax translocation to the nucleus in a subset of dying cells.
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Affiliation(s)
- E López
- Hospital Prínceps d'Espanya, Departament de Biologia Cellular i Anatomia Patològica, Facultat de Medecina, Universitat de Barcelona, Hospitalet de Llobregat, Spain
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37
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Moore DB, Walker DW, Heaton MB. Neonatal ethanol exposure alters bcl-2 family mRNA levels in the rat cerebellar vermis. Alcohol Clin Exp Res 1999; 23:1251-61. [PMID: 10443994 DOI: 10.1111/j.1530-0277.1999.tb04286.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND The objective of the present work was to determine whether ethanol-induced cerebellar cell death during development is related to alterations in the expression of bcl-2 family genes. METHODS Rats were exposed to ethanol or control conditions during the neonatal period and transcript levels of bcl-2 family members relative to cyclophilin were determined. Pups exposed in parallel were taken for cerebellar cell counts. RESULTS Ethanol exposure during the first postnatal week significantly reduced Purkinje and granule cell numbers by postnatal day 21 (P21). Acute first postnatal week ethanol exposure up-regulated mRNA transcripts encoding the cell death-promoting molecules bax and bcl-xs as measured on P4. An additional day of exposure on P5 resulted in no further alterations in bcl-2 family transcripts, likely because Purkinje cell death was detectable as early as P5. To determine whether proapoptotic gene expression changes were specific to first postnatal week ethanol neurotoxicity, we examined bcl-2 family mRNA levels in rats exposed to ethanol during a developmental period of cerebellar insusceptibility, the second postnatal week. Exposure on P7 to P8 produced no change in cerebellar cell number, but also resulted in increased levels of bax, although only after 2-day ethanol exposure and not after acute exposure on P7. CONCLUSIONS These data implicate altered expression of proapoptotic members of the bcl-2 gene family in acute ethanol-mediated cerebellar cell death during the first postnatal week. They also suggest that the differential survival of cerebellar neurons after ethanol exposure during more mature developmental stages may be related to more successful suppression of proapoptotic processes.
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Affiliation(s)
- D B Moore
- Department of Neuroscience, University of Florida College of Medicine, University of Florida Brain Institute, Gainesville 32610, USA
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38
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Hamnér S, Skoglösa Y, Lindholm D. Differential expression of bcl-w and bcl-x messenger RNA in the developing and adult rat nervous system. Neuroscience 1999; 91:673-84. [PMID: 10366024 DOI: 10.1016/s0306-4522(98)00642-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The bcl-2 family of proteins comprises both anti-apoptotic and pro-apoptotic members, which play a pivotal role in regulating cell death. Bcl-w is a recently identified member of this family, which was shown to inhibit apoptosis in haemopoietic cell lines. However, the function and expression patterns of bcl-w in the nervous system have so far not been described. We have cloned complementary DNA corresponding to rat bcl-w and analysed the expression of bcl-w messenger RNA during rat brain development, using RNA blotting and in situ hybridization techniques. We also compared the expression patterns of bcl-w with those of bcl-xL. During brain development, the levels of bcl-w messenger RNA were found to increase, with highest expression located to specific regions of the mature brain, such as hippocampus, cerebellum, piriform cortex and locus coeruleus. Bcl-w messenger RNA was expressed by neurons, as shown with double labeling with neuronal markers. In contrast to bcl-w, bcl-xL messenger RNA expression levels were highest during early development, particularly in cortex, hippocampus, thalamus, spinal cord and dorsal root ganglia. During postnatal development the expression of bcl-xL messenger RNA decreased and were only detected at low levels in the adult nervous system. As shown earlier for bcl-2, the expression of bcl-w and bcl-x messenger RNA in cultured cerebellar granule cells was not altered by the deprivation of neurotrophic factors. The present results suggest that bcl-w may play an important role in the mature nervous system.
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Affiliation(s)
- S Hamnér
- Department of Neuroscience, Developmental Neuroscience, Uppsala, Sweden
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39
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Abstract
Bcl-2 and bcl-xL are proteins known to inhibit cell death (apoptosis). Expression of these proteins in gangliogliomas has not been extensively examined. This study retrospectively evaluates bcl-2 and bcl-x immunostaining in paraffin-embedded materials in gangliogliomas. Twenty-nine gangliogliomas in 17 males and 12 females, age 2.5 to 47 years (mean, 20.7 years), were studied. Nineteen tumors were situated primarily in the temporal lobe. All but three patients presented with seizures ranging from 3 months to 28 years' duration (mean, 11.1 years) before surgery. All tumors histologically were comprised of an atypical neuronal component and a glioma component, which most frequently resembled a low-grade astrocytoma. Cortical dysplasia was observed adjacent to eight tumors. MIB-1 (marker of cell proliferation) labeling indices (percentage of positively staining tumor cell nuclei) ranged from 0 to 7.7 (mean, 0.8). bcl-2 staining was observed in 25 tumors (86%); neuronal staining was present in 24 cases (83%), and glial cell staining in 21 tumors (72%). Bcl-xL staining was only observed in eight gangliogliomas (28%); in all eight tumors (28%), neuronal staining was seen, and focal glial cell staining was present in two cases (7%). Four tumors (14%) did not stain with either bcl-2 or bcl-xL. There appeared to be no relationship between MIB-1 immunostaining and staining with bcl-2 or bcl-xL. bcl-2 expression by immunohistochemistry was observed more frequently than bcl-xL in gangliogliomas. Expression of these proteins may reflect abnormalities of apoptosis, which could play a role in the survival of cells that may be involved in the development of gangliogliomas.
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Affiliation(s)
- R A Prayson
- Department of Pathology, Cleveland Clinic Foundation, OH 44195, USA
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López E, Pozas E, Rivera R, Ferrer I. Bcl-2 and Bax expression following methylazoxymethanol acetate-induced apoptosis in the external granule cell layer of the developing rat cerebellum. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1999; 112:149-53. [PMID: 9974170 DOI: 10.1016/s0165-3806(98)00169-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Since Bcl-2 protects a variety of cell types from programmed cell death, whereas Bax promotes apoptosis, the present study examines Bcl-2 and Bax proteins, and bcl-2 and bax mRNA expression in the developing cerebellum of the rat following methylazoxymethanol (MAM) acetate administration by using immunohistochemistry, Western blotting and Northern blotting. Bcl-2 expression in the developing cerebellum is observed in proliferating and differentiating cells, whereas Bax expression is higher in differentiating cells than in proliferating cells during development. Administration of MAM (0.05 microliter/g, i.p.) at postnatal day 3 produces apoptotic cell death, as detected by the characteristic morphology and positivity with the method of in situ end-labeling of nuclear DNA fragmentation of dying cells, in the external granule cell layer of the cerebellum. Dying cells are not stained with Bcl-2 and Bax antibodies. Furthermore, no modification in the intensity of Bcl-2 and Bax protein bands and in the intensity of Bcl-2 and bax mRNA bands on Western and Northern blots, respectively, were observed between control and treated rats. These data indicate that MAM-induced apoptosis is not associated with modifications in the expression of Bcl-2 and Bax.
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Affiliation(s)
- E López
- Unitat de Neuropatologia, Hospital Prínceps d'Espanya (Bellvitge), Barcelona, Spain
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Lossi L, Zagzag D, Greco MA, Merighi A. Apoptosis of undifferentiated progenitors and granule cell precursors in the postnatal human cerebellar cortex correlates with expression of BCL‐2, ICE, and CPP32 proteins. J Comp Neurol 1998. [DOI: 10.1002/(sici)1096-9861(19980928)399:3<359::aid-cne5>3.0.co;2-#] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Laura Lossi
- Dipartimento di Morfofisiologia Veterinaria, Università degli Studi di Torino, I‐10126 Torino, Italy
| | - David Zagzag
- Department of Pathology, Division of Neuropathology, New York University Medical Center, New York, New York 10016
- Division of Pediatric Pathology, New York University Medical Center, New York, New York 10016
| | - M. Alba Greco
- Division of Pediatric Pathology, New York University Medical Center, New York, New York 10016
| | - Adalberto Merighi
- Dipartimento di Morfofisiologia Veterinaria, Università degli Studi di Torino, I‐10126 Torino, Italy
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Mouihate A, Pittman QJ. Lipopolysaccharide-induced fever is dissociated from apoptotic cell death in the rat brain. Brain Res 1998; 805:95-103. [PMID: 9733932 DOI: 10.1016/s0006-8993(98)00675-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Immune system activation induces increase in expression level and enzymatic activity of interleukin-1 beta converting enzyme (ICE) in rat brain. As ICE has been implicated in apoptotic cell death, a possible link may exist between immune system activation by bacterial endotoxic lipopolysaccharide (LPS) and apoptosis in rat brain. The aim of this study was to investigate possible effect of acute (5.5 h) or chronic (5 days) intraperitoneal (i.p.) administration and central injection of LPS on brain apoptotic cell death. Body temperature was continuously monitored for fever, a hallmark of immune activation. Detection of apoptotic cell death was carried out by using in situ labelling of DNA fragmentation in various brain structures. Despite the chronic or the acute pyrogenic effects of LPS, no evidence for apoptotic cell death was observed in any of the brain areas analysed, including hippocampus, hypothalamus, area postrema, subfornical organ, organum vasculosum of the lamina terminalis and nucleus tractus solitaris. Other well-known sites of apoptotic cell death, including brain of ischemic rat, mammary gland of post-lactating rat and rat intestine as well as Dnase-treated rat brain slices, were used as positive controls. These results suggest that ICE activation during fever development is dissociated from cell death by apoptosis in rat brain. Unlike peripheral targets of immunocompetent cytokines, a protective system, yet to be defined, may be present in the central nervous system and block the deleterious effects of infectious agents and cytokines.
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Affiliation(s)
- A Mouihate
- Neuroscience Research Group, Department of Physiology and Biophysics, Faculty of Medicine, University of Calgary, 3330 Hospital Drive, NW, Calgary, Alberta, Canada.
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Zanjani H, Rondi-Reig L, Vogel M, Martinou JC, Delhaye-Bouchaud N, Mariani J. Overexpression of a Hu-bcl-2 transgene in Lurcher mutant mice delays Purkinje cell death. COMPTES RENDUS DE L'ACADEMIE DES SCIENCES. SERIE III, SCIENCES DE LA VIE 1998; 321:633-40. [PMID: 9769861 DOI: 10.1016/s0764-4469(98)80002-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cerebellar Purkinje cells in the heterozygous Lurcher mutant undergo cell autonomous degeneration beginning in the second week of postnatal development and becoming almost total around 30-45 days. The Lurcher mutation was recently identified as gain-of-function defect in the delta 2 glutamate receptor causing a constitutive current leak, suggesting that +/Lc Purkinje cells die by an excitotoxic mechanism. In previous studies we have shown that overexpression of bcl-2, a key regulator of cell death, in the heterozygous Lurcher mutant does not prevent +/Lc Purkinje cell death. To investigate further the mechanisms of +/Lc Purkinje cell death, we have crossed +/Lc mutants with a second line of Hu-bcl-2 transgenics (NSE73a) that shows an earlier onset of transgene expression and higher expression levels. Analysis of eight +/Lc-NSE73a mutants (4 at 2 months and 4 at 5-6 months) showed that Hu-bcl-2 overexpression delayed, but ultimately could not prevent +/Lc Purkinje cell death.
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Affiliation(s)
- H Zanjani
- Laboratoire de neurobiologie du développement, Université Pierre-et-Marie-Curie, Paris, France
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Abstract
The distribution of neurons expressing immunoreactivity for the protein Bcl-2 was studied in the brain of squirrel monkeys (Saimiri sciureus) of various ages. Several subsets of small and intensely immunoreactive neurons displaying an immature appearance were disclosed in the amygdala and piriform cortex. The piriform cortex exhibited clusters of various forms in which Bcl-2+ neurons appeared linked to one another by their own neurites. The subventricular zone, which is known to harbor the largest population of rapidly and constitutively proliferating cells in the adult rat brain, was intensely stained, particularly at the basis of the lateral ventricle. A long and dorsoventrally oriented Bcl-2+ fiber fascicle was seen to emerge from the subventricular zone, together with numerous Bcl-2+ cells that formed a densely packed column directed at the olfactory tubercle. In adult and aged monkeys, the small and intensely labeled neurons were progressively replaced by larger and more weakly stained neurons in the amygdala and piriform cortex. In contrast, Bcl-2 immunostaining did not change with age in the subventricular zone and olfactory tubercle, the islands of Calleja of which were markedly enriched with Bcl-2. The dentate gyrus contained only a few layers of intensely labeled granule cells in juvenile monkeys, but the number of these layers increased markedly in adult and aged monkeys. These findings suggest that Bcl-2 can serve as a marker of both proliferating and differentiating neurons and indicate that such immature neurons may be much more widespread than previously thought in postnatal primate brain.
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Perovic S, Böhm M, Meesters E, Meinhardt A, Pergande G, Müller WE. Pharmacological intervention in age-associated brain disorders by Flupirtine: Alzheimer's and prion diseases. Mech Ageing Dev 1998; 101:1-19. [PMID: 9593309 DOI: 10.1016/s0047-6374(97)00152-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease, a major form of dementia in the elderly has become an increasingly important health problem in developed countries. In vitro studies on primary neurons demonstrate that Flupirtine (Katadolon) at a concentration of 1 microg/ml, significantly reduces the neurotoxic (apoptotic) effect displayed by A beta25-35, a segment of the amyloid beta-protein precursor the etiologic agent of Alzheimer's disease. Flupirtine, which has been in clinical use since 10 years ago, prevents the toxic effect of PrP, the presumed etiologic agent of the Creutzfeldt-Jakob disease as well as the excitatory amino acid glutamate on cortical neurons. Flupirtine displays a bimodal activity. Its strongest cytoprotective effect against glutamate-induced neurotoxicity was measured if administered at least 120 min prior to the addition of the glutamate. A likewise potent anti-apoptotic activity was measured if cells were simultaneously incubated with Flupirtine and the apoptotic inducers. Administration of Flupirtine during postincubation time in the experiments with glutamate did not result in neuroprotection. In parallel with the determination of the effect of Flupirtine on the toxin (A beta, PrP or glutamate)-induced neuronal death the effect of the drug on the intracellular Ca2+ level [Ca2+]i, was measured. It is well established that incubation of neurons with glutamate causes an increase in [Ca2+]i. It was found that a simultaneous administration of Flupirtine and glutamate did not reduce the glutamate-induced high Ca2+ level. Only if the cells had been preincubated for approximately 30 min with the drug the intracellular Ca2+ level was significantly lower. Experimental evidence given here shows that the molecular basis for the antiapoptotic effect of Flupirtine against glutamate, triggered during pre-incubation, is an increased expression of the protooncogene bcl-2. The neuroprotective effect determined during coincubation with the inducer is attributed to a normalization of the glutathione level which dropped in the presence of the inducers. It is concluded that Flupirtine is a promising drug to treat neurodegenerative disorders occurring with age, e.g. Alzheimer's disease and prion based diseases, like Creutzfeldt-Jakob disease. This conclusion is corroborated by the favourable pharmacokinetic profile of Flupirtine.
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Affiliation(s)
- S Perovic
- Institut für Physiologische Chemie, Abteilung Angewandte Molekülarbiologie, Universität, Mainz, Germany
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Yachnis AT, Giovanini MA, Eskin TA, Reier PJ, Anderson DK. Developmental patterns of BCL-2 and BCL-X polypeptide expression in the human spinal cord. Exp Neurol 1998; 150:82-97. [PMID: 9514825 DOI: 10.1006/exnr.1997.6746] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The cell death suppressors bcl-2 and bcl-x are developmentally regulated and may modulate physiologic cell death in the central nervous system (CNS). However, little data are currently available on the expression patterns of these polypeptides in the human CNS. We examined the ontogeny of bcl-2 and bcl-x in 12 human spinal cords of gestational ages (GA) between 5 and 39 weeks and in 3 adult cords. Paraffin sections were probed by immunohistochemistry using well-characterized, commercially available antibodies that had been raised against poorly conserved epitopes of these homologous proteins. Between 5 and 10 weeks GA, bcl-2 immunoreactivity was identified in primitive neuroepithelial cells of the ventricular zone. Individual cells of the mantle zone were stained including clusters of early anterior horn cells. Bcl-x immunoreactivity was most prominent in differentiating neurons of the mantle zone and less pronounced in the ventricular zone. Between 10 and 14 weeks GA, bcl-2 staining was observed in cells lining the central canal, neurons of the dorsal horn (especially laminae I and II), and in anterior horn cells. The latter exhibited a range of staining intensities from moderate to nondetectable. Bcl-2 immunoreactivity became markedly reduced between 15 and 25 weeks GA, persisting only in ependymal cells. In contrast, strong bcl-x staining was observed in most neurons throughout development and into adulthood. The period of apparent bcl-2 down-regulation overlaps with a peak in physiologic motoneuron death and the establishment of functional neuromuscular synapses in the human spinal cord. These findings suggest that bcl-2 and bcl-x may both be required for survival of early postmitotic neurons before appropriate synaptic connections have been established. Continued neuronal survival (after bcl-2 is down-regulated) may require persistent bcl-x expression in addition to target-derived neurotrophic factors made available through the formation of appropriate synapses.
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Affiliation(s)
- A T Yachnis
- Department of Pathology, University of Florida Brain Institute, Gainesville
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Kanazawa K, Imaizumi K, Mori T, Honma Y, Tojo M, Tanno Y, Yokoya S, Niwa S, Tohyama M, Takagi T, Wanaka A. Expression pattern of a novel death-promoting gene, DP5, in the developing murine nervous system. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1998; 54:316-20. [PMID: 9555074 DOI: 10.1016/s0169-328x(97)00360-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We examined the expression patterns of the DP5 gene, which encodes a protein with apoptosis-inducing activity, in the developing nervous system of mice. This gene was primarily expressed in the spinal motor neurons and peripheral sensory ganglia of mouse embryos and transiently in the postnatal brain, particularly in the entorhinal cortex and hippocampus. These expression patterns suggest that the DP5 gene may be involved in the apoptosis, if not all, of the developing nervous system.
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Affiliation(s)
- K Kanazawa
- Department of Cell Science, Institute of Biomedical Sciences, Osaka University Medical School, Osaka 565, Japan
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Abstract
Apoptosis is a fundamental biological process used by all muticellular organisms to eliminate unwanted or superfluous cells, and is a prominent feature of normal neural development. Developmentally occurring neuronal apoptosis serves to match the number of neurons to the requirements of their synaptic targets and to rid the nervous system of inappropriate connections. While it is generally accepted that apoptosis is a "suicide program" inherent in all cells, the molecular basis of this program is just beginning to be unraveled. Evidence from numerous recent studies indicate that a variety of proteins are involved in the transmission of external signals to the cell-death machinery within the cell. This review describes many of the recent findings of the regulatory pathways and genes that have been implicated in the induction or suppression of apoptosis in neurons.
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Affiliation(s)
- S R D'Mello
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut 06269, USA
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Bernier PJ, Parent A. The anti-apoptosis bcl-2 proto-oncogene is preferentially expressed in limbic structures of the primate brain. Neuroscience 1998; 82:635-40. [PMID: 9483524 DOI: 10.1016/s0306-4522(97)00384-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
By virtue of its capacity to prevent apoptosis the protooncogene bcl-2 is believed to play a crucial role in CNS development. Studies in rodents have shown that the anti-apoptosis Bcl-2 protein is widely expressed during CNS development, but undergoes a marked down-regulation during maturation and is present only at low concentrations in adult CNS. In contrast, current data suggest that Bcl-2 protein in adult monkey brain results from microglial expression. In the present immunohistochemical study, however, numerous subsets of Bcl-2-immunoreactive neurons were encountered in the amygdala, hippocampus, hypothalamus, limbic cortices and striatum of squirrel monkeys. Of particular interest was the presence in the basal portion of the amygdala and adjoining piriform cortex of numerous intensely immunoreactive cells with long and thick immunopositive processes that ran into the ventral amygdalofugal pathway. At striatal level Bcl-2-positive neurons were strictly confined to calbindin-poor striosomes, which are specifically innervated by limbic cortices. This study has provided the first evidence for the occurrence of Bcl-2 in mature monkey brain. It has further shown that this protein is preferentially expressed in limbic structures in primate forebrain. The sustained expression of this anti-apoptosis protein may protect limbic system neurons from various injuries or neurodegeneration. It may also be involved in the functional and structural changes that occur throughout adulthood in some regions of the primate limbic system.
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Affiliation(s)
- P J Bernier
- Centre de recherche Université Laval Robert-Giffard, Beauport, Québec, Canada
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Postnatal expression of Hu-bcl-2 gene in Lurcher mutant mice fails to rescue Purkinje cells but protects inferior olivary neurons from target-related cell death. J Neurosci 1998. [PMID: 9412510 DOI: 10.1523/jneurosci.18-01-00319.1998] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The Lurcher mutant has been extensively studied as a model for cell-autonomous and target-related cell death, yet there are still many unknowns concerning the mechanisms of neuronal degeneration in this mutant. As a key regulator of apoptosis, a bcl-2 transgene has been overexpressed in the heterozygous Lurcher mutant to investigate the effects of BCL-2 on two types of in vivo neuronal cell loss in Lurcher: cell-autonomous Purkinje cell degeneration and target-related olivary neuron death. Six adult +/Lc mutants expressing a human bcl-2 transgene (Hu-bcl-2) were generated by crossing +/Lc mutants with NSE71 Hu-bcl-2 transgenic mice. Analysis of these brains showed that bcl-2 overexpression did not prevent +/Lc Purkinje cell degeneration, but it did rescue most olivary neurons from target-related cell death. Although the number of olivary neurons was equivalent to wild-type numbers, the inferior olive nucleus was significantly shorter in its rostrocaudal extent, suggesting that olivary neurons are atrophied. We propose that Lurcher gene action causes Purkinje cell degeneration independently of a BCL-2-mediated pathway. Furthermore, although bcl-2 overexpression rescues olivary neurons from target-related cell death, it does not prevent the atrophy associated with the loss of target-related trophic support.
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