1
|
Eesmaa A, Yu LY, Göös H, Danilova T, Nõges K, Pakarinen E, Varjosalo M, Lindahl M, Lindholm P, Saarma M. CDNF Interacts with ER Chaperones and Requires UPR Sensors to Promote Neuronal Survival. Int J Mol Sci 2022; 23:ijms23169489. [PMID: 36012764 PMCID: PMC9408947 DOI: 10.3390/ijms23169489] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/16/2022] [Accepted: 08/20/2022] [Indexed: 11/16/2022] Open
Abstract
Cerebral dopamine neurotrophic factor (CDNF) is a neurotrophic factor that has beneficial effects on dopamine neurons in both in vitro and in vivo models of Parkinson's disease (PD). CDNF was recently tested in phase I-II clinical trials for the treatment of PD, but the mechanisms underlying its neuroprotective properties are still poorly understood, although studies have suggested its role in the regulation of endoplasmic reticulum (ER) homeostasis and the unfolded protein response (UPR). The aim of this study was to investigate the mechanism of action of CDNF through analyzing the involvement of UPR signaling in its anti-apoptotic function. We used tunicamycin to induce ER stress in mice in vivo and used cultured primary neurons and found that CDNF expression is regulated by ER stress in vivo and that the involvement of UPR pathways is important for the neuroprotective function of CDNF. Moreover, we used AP-MS and BiFC to perform the first interactome screening for CDNF and report novel binding partners of CDNF. These findings allowed us to hypothesize that CDNF protects neurons from ER-stress-inducing agents by modulating UPR signaling towards cell survival outcomes.
Collapse
|
2
|
Lindholm P, Saarma M. Cerebral dopamine neurotrophic factor protects and repairs dopamine neurons by novel mechanism. Mol Psychiatry 2022; 27:1310-1321. [PMID: 34907395 PMCID: PMC9095478 DOI: 10.1038/s41380-021-01394-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 11/09/2021] [Accepted: 11/15/2021] [Indexed: 12/20/2022]
Abstract
Midbrain dopamine neurons deteriorate in Parkinson's disease (PD) that is a progressive neurodegenerative movement disorder. No cure is available that would stop the dopaminergic decline or restore function of injured neurons in PD. Neurotrophic factors (NTFs), e.g., glial cell line-derived neurotrophic factor (GDNF) are small, secreted proteins that promote neuron survival during mammalian development and regulate adult neuronal plasticity, and they are studied as potential therapeutic agents for the treatment of neurodegenerative diseases. However, results from clinical trials of GDNF and related NTF neurturin (NRTN) in PD have been modest so far. In this review, we focus on cerebral dopamine neurotrophic factor (CDNF), an unconventional neurotrophic protein. CDNF delivered to the brain parenchyma protects and restores dopamine neurons in animal models of PD. In a recent Phase I-II clinical trial CDNF was found safe and well tolerated. CDNF deletion in mice led to age-dependent functional changes in the brain dopaminergic system and loss of enteric neurons resulting in slower gastrointestinal motility. These defects in Cdnf-/- mice intriguingly resemble deficiencies observed in early stage PD. Different from classical NTFs, CDNF can function both as an extracellular trophic factor and as an intracellular, endoplasmic reticulum (ER) luminal protein that protects neurons and other cell types against ER stress. Similarly to the homologous mesencephalic astrocyte-derived neurotrophic factor (MANF), CDNF is able to regulate ER stress-induced unfolded protein response (UPR) signaling and promote protein homeostasis in the ER. Since ER stress is thought to be one of the pathophysiological mechanisms contributing to the dopaminergic degeneration in PD, CDNF, and its small-molecule derivatives that are under development may provide useful tools for experimental medicine and future therapies for the treatment of PD and other neurodegenerative protein-misfolding diseases.
Collapse
Affiliation(s)
- Päivi Lindholm
- grid.7737.40000 0004 0410 2071Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, FI-00014 Helsinki, Finland
| | - Mart Saarma
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, FI-00014, Helsinki, Finland.
| |
Collapse
|
3
|
Small-Molecule Inhibitors of the RNA M6A Demethylases FTO Potently Support the Survival of Dopamine Neurons. Int J Mol Sci 2021; 22:ijms22094537. [PMID: 33926120 PMCID: PMC8123663 DOI: 10.3390/ijms22094537] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/20/2021] [Accepted: 04/22/2021] [Indexed: 12/21/2022] Open
Abstract
The fat mass and obesity-associated protein (FTO), an RNA N6-methyladenosine (m6A) demethylase, is an important regulator of central nervous system development, neuronal signaling and disease. We present here the target-tailored development and biological characterization of small-molecule inhibitors of FTO. The active compounds were identified using high-throughput molecular docking and molecular dynamics screening of the ZINC compound library. In FTO binding and activity-inhibition assays the two best inhibitors demonstrated Kd = 185 nM; IC50 = 1.46 µM (compound 2) and Kd = 337 nM; IC50 = 28.9 µM (compound 3). Importantly, the treatment of mouse midbrain dopaminergic neurons with the compounds promoted cellular survival and rescued them from growth factor deprivation induced apoptosis already at nanomolar concentrations. Moreover, both the best inhibitors demonstrated good blood-brain-barrier penetration in the model system, 31.7% and 30.8%, respectively. The FTO inhibitors demonstrated increased potency as compared to our recently developed ALKBH5 m6A demethylase inhibitors in protecting dopamine neurons. Inhibition of m6A RNA demethylation by small-molecule drugs, as presented here, has therapeutic potential and provides tools for the identification of disease-modifying m6A RNAs in neurogenesis and neuroregeneration. Further refinement of the lead compounds identified in this study can also lead to unprecedented breakthroughs in the treatment of neurodegenerative diseases.
Collapse
|
4
|
Inhibition of PI3K/AKT/mTOR signaling pathway promotes autophagy and relieves hyperalgesia in diabetic rats. Neuroreport 2020; 31:644-649. [DOI: 10.1097/wnr.0000000000001461] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
5
|
Ardashov OV, Pavlova AV, Mahato AK, Sidorova Y, Morozova EA, Korchagina DV, Salnikov GE, Genaev AM, Patrusheva OS, Li-Zhulanov NS, Tolstikova TG, Volcho KP, Salakhutdinov NF. A Novel Small Molecule Supports the Survival of Cultured Dopamine Neurons and May Restore the Dopaminergic Innervation of the Brain in the MPTP Mouse Model of Parkinson's Disease. ACS Chem Neurosci 2019; 10:4337-4349. [PMID: 31464415 DOI: 10.1021/acschemneuro.9b00396] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We previously showed that monoterpenoid (1R,2R,6S)-3-methyl-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diol 1 alleviates motor manifestations of Parkinson's disease in animal models. In the present study, we designed and synthesized monoepoxides of (1R,2R,6S)-3-methyl-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diol 1 and evaluated their biological activity in the MPTP mouse model of Parkinson's disease. We also assessed the ability of these compounds to penetrate the blood-brain barrier (BBB). According to these data, we chose epoxide 4, which potently restored the locomotor activity in MPTP-treated mice and efficiently penetrated the BBB, to further explore its potential mechanism of action. Epoxide 4 was found to robustly promote the survival of cultured dopamine neurons, protect dopamine neurons against toxin-induced degeneration, and trigger the mitogen-activated protein kinase (MAPK) signaling cascade in cells of neuronal origin. Meanwhile, neither the survival-promoting effect nor MAPK activation was observed in non-neuronal cells treated with epoxide 4. In the MPTP mouse model of Parkinson's disease, compound 4 increased the density of dopamine neuron fibers in the striatum, which can highlight its potential to stimulate striatal reinnervation and thus halt disease progression. Taken together, these data indicate that epoxide 4 can be a promising compound for further development, not only as a symptomatic but also as a neuroprotective and neurorestorative drug for Parkinson's disease.
Collapse
Affiliation(s)
- Oleg V. Ardashov
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev ave., 9, 630090 Novosibirsk, Russian Federation
- Novosibirsk State University, Pirogova, 2, 630090 Novosibirsk, Russian Federation
| | - Alla V. Pavlova
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev ave., 9, 630090 Novosibirsk, Russian Federation
| | - Arun Kumar Mahato
- Laboratory of Molecular Neuroscience, Institute of Biotechnology, HiLIFe, University of Helsinki, Viikinkaari 5D, 00014, Helsinki, Finland
| | - Yulia Sidorova
- Laboratory of Molecular Neuroscience, Institute of Biotechnology, HiLIFe, University of Helsinki, Viikinkaari 5D, 00014, Helsinki, Finland
| | - Ekaterina A. Morozova
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev ave., 9, 630090 Novosibirsk, Russian Federation
| | - Dina V. Korchagina
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev ave., 9, 630090 Novosibirsk, Russian Federation
| | - Georgi E. Salnikov
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev ave., 9, 630090 Novosibirsk, Russian Federation
- Novosibirsk State University, Pirogova, 2, 630090 Novosibirsk, Russian Federation
| | - Alexander M. Genaev
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev ave., 9, 630090 Novosibirsk, Russian Federation
| | - Oksana S. Patrusheva
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev ave., 9, 630090 Novosibirsk, Russian Federation
| | - Nikolay S. Li-Zhulanov
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev ave., 9, 630090 Novosibirsk, Russian Federation
- Novosibirsk State University, Pirogova, 2, 630090 Novosibirsk, Russian Federation
| | - Tat’yana G. Tolstikova
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev ave., 9, 630090 Novosibirsk, Russian Federation
| | - Konstantin P. Volcho
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev ave., 9, 630090 Novosibirsk, Russian Federation
- Novosibirsk State University, Pirogova, 2, 630090 Novosibirsk, Russian Federation
| | - Nariman F. Salakhutdinov
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev ave., 9, 630090 Novosibirsk, Russian Federation
- Novosibirsk State University, Pirogova, 2, 630090 Novosibirsk, Russian Federation
| |
Collapse
|
6
|
Dewanjee S, Das S, Das AK, Bhattacharjee N, Dihingia A, Dua TK, Kalita J, Manna P. Molecular mechanism of diabetic neuropathy and its pharmacotherapeutic targets. Eur J Pharmacol 2018; 833:472-523. [DOI: 10.1016/j.ejphar.2018.06.034] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 06/15/2018] [Accepted: 06/26/2018] [Indexed: 02/07/2023]
|
7
|
Priante G, Quaggio F, Gianesello L, Ceol M, Cristofaro R, Terrin L, Furlan C, Del Prete D, Anglani F. Caspase-independent programmed cell death triggers Ca 2PO 4 deposition in an in vitro model of nephrocalcinosis. Biosci Rep 2018; 38:BSR20171228. [PMID: 29208768 PMCID: PMC5770611 DOI: 10.1042/bsr20171228] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 12/01/2017] [Accepted: 12/04/2017] [Indexed: 01/12/2023] Open
Abstract
Nephrocalcinosis involves the deposition of microscopic crystals in the tubular lumen or interstitium. While the clinical, biochemical, and genetic aspects of the diseases causing nephrocalcinosis have been elucidated, little is known about the cellular events in this calcification process. We previously reported a phenomenon involving the spontaneous formation of Ca2PO4 nodules in primary papillary renal cells from a patient with medullary nephrocalcinosis harboring a rare glial cell-derived neurotrophic factor (GDNF) gene variant. We also demonstrated that cultivating GDNF-silenced human kidney-2 (HK-2) cells in osteogenic conditions for 15 days triggered Ca2PO4 deposits. Given the reportedly close relationship between cell death and pathological calcification, aim of the present study was to investigate whether apoptosis is involved in the calcification of GDNF-silenced HK-2 cells under osteogenic conditions. Silenced and control cells were cultured in standard and osteogenic medium for 1, 5, and 15 days, and any Ca2PO4 deposition was identified by means of von Kossa staining and environmental SEM (ESEM) analyses. Based on the results of annexin V and propidium iodide (PI) analysis, and terminal deoxynucleotidyl transferase dUTP-biotin nick end labeling (TUNEL) assay, the silenced cells in the osteogenic medium showed a significant increase in the percentage of cells in the late phase of apoptosis and an increased Ca2PO4 deposition at 15 days. The results of quantitative real-time PCR (qRT-PCR) of BAX and BCL2, and in-cell Western analysis of caspases indicated that the cell death process was independent of caspase-3, -6, -7, and -9 activation, however. Using this model, we provide evidence of caspase-independent cell death triggering the calcification process in GDNF-silenced HK-2 cells.
Collapse
Affiliation(s)
- Giovanna Priante
- Department of Medicine - DIMED, Kidney Histomorphology and Molecular Biology Laboratory, Clinical Nephrology, University of Padua, Padua, Italy
| | - Federica Quaggio
- Department of Medicine - DIMED, Kidney Histomorphology and Molecular Biology Laboratory, Clinical Nephrology, University of Padua, Padua, Italy
| | - Lisa Gianesello
- Department of Medicine - DIMED, Kidney Histomorphology and Molecular Biology Laboratory, Clinical Nephrology, University of Padua, Padua, Italy
| | - Monica Ceol
- Department of Medicine - DIMED, Kidney Histomorphology and Molecular Biology Laboratory, Clinical Nephrology, University of Padua, Padua, Italy
| | - Rosalba Cristofaro
- Department of Medicine - DIMED, Kidney Histomorphology and Molecular Biology Laboratory, Clinical Nephrology, University of Padua, Padua, Italy
| | - Liliana Terrin
- Department of Medicine - DIMED, Kidney Histomorphology and Molecular Biology Laboratory, Clinical Nephrology, University of Padua, Padua, Italy
| | - Claudio Furlan
- Center for Laboratory Analyses and Certification Services (CEASC), University of Padua, Padua, Italy
| | - Dorella Del Prete
- Department of Medicine - DIMED, Kidney Histomorphology and Molecular Biology Laboratory, Clinical Nephrology, University of Padua, Padua, Italy
| | - Franca Anglani
- Department of Medicine - DIMED, Kidney Histomorphology and Molecular Biology Laboratory, Clinical Nephrology, University of Padua, Padua, Italy
| |
Collapse
|
8
|
Neurotrophic Factors NGF, GDNF and NTN Selectively Modulate HSV1 and HSV2 Lytic Infection and Reactivation in Primary Adult Sensory and Autonomic Neurons. Pathogens 2017; 6:pathogens6010005. [PMID: 28178213 PMCID: PMC5371893 DOI: 10.3390/pathogens6010005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 01/31/2017] [Accepted: 02/02/2017] [Indexed: 12/15/2022] Open
Abstract
Herpes simplex viruses (HSV1 and HSV2) establish latency in peripheral ganglia after ocular or genital infection, and can reactivate to produce different patterns and frequencies of recurrent disease. Previous studies showed that nerve growth factor (NGF) maintains HSV1 latency in embryonic sympathetic and sensory neurons. However, adult sensory neurons are no longer dependent on NGF for survival, some populations cease expression of NGF receptors postnatally, and the viruses preferentially establish latency in different populations of sensory neurons responsive to other neurotrophic factors (NTFs). Thus, NGF may not maintain latency in adult sensory neurons. To identify NTFs important for maintaining HSV1 and HSV2 latency in adult neurons, we investigated acute and latently-infected primary adult sensory trigeminal (TG) and sympathetic superior cervical ganglia (SCG) after NTF removal. NGF and glial cell line-derived neurotrophic factor (GDNF) deprivation induced HSV1 reactivation in adult sympathetic neurons. In adult sensory neurons, however, neurturin (NTN) and GDNF deprivation induced HSV1 and HSV2 reactivation, respectively, while NGF deprivation had no effects. Furthermore, HSV1 and HSV2 preferentially reactivated from neurons expressing GFRα2 and GFRα1, the high affinity receptors for NTN and GDNF, respectively. Thus, NTN and GDNF play a critical role in selective maintenance of HSV1 and HSV2 latency in primary adult sensory neurons.
Collapse
|
9
|
Pham DD, Do HT, Bruelle C, Kukkonen JP, Eriksson O, Mogollón I, Korhonen LT, Arumäe U, Lindholm D. p75 Neurotrophin Receptor Signaling Activates Sterol Regulatory Element-binding Protein-2 in Hepatocyte Cells via p38 Mitogen-activated Protein Kinase and Caspase-3. J Biol Chem 2016; 291:10747-58. [PMID: 26984409 PMCID: PMC4865921 DOI: 10.1074/jbc.m116.722272] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 03/15/2016] [Indexed: 11/06/2022] Open
Abstract
Nerve growth factor (NGF) influences the survival and differentiation of a specific population of neurons during development, but its role in non-neuronal cells has been less studied. We observed here that NGF and its pro-form, pro-NGF, are elevated in fatty livers from leptin-deficient mice compared with controls, concomitant with an increase in low density lipoprotein receptors (LDLRs). Stimulation of mouse primary hepatocytes with NGF or pro-NGF increased LDLR expression through the p75 neurotrophin receptor (p75NTR). Studies using Huh7 human hepatocyte cells showed that the neurotrophins activate the sterol regulatory element-binding protein-2 (SREBP2) that regulates genes involved in lipid metabolism. The mechanisms for this were related to stimulation of p38 mitogen-activated protein kinase (p38 MAPK) and activation of caspase-3 and SREBP2 cleavage following NGF and pro-NGF stimulations. Cell fractionation experiments showed that caspase-3 activity was increased particularly in the membrane fraction that harbors SREBP2 and caspase-2. Experiments showed further that caspase-2 interacts with pro-caspase-3 and that p38 MAPK reduced this interaction and caused caspase-3 activation. Because of the increased caspase-3 activity, the cells did not undergo cell death following p75NTR stimulation, possibly due to concomitant activation of nuclear factor-κB (NF-κB) pathway by the neurotrophins. These results identify a novel signaling pathway triggered by ligand-activated p75NTR that via p38 MAPK and caspase-3 mediate the activation of SREBP2. This pathway may regulate LDLRs and lipid uptake particularly after injury or during tissue inflammation accompanied by an increased production of growth factors, including NGF and pro-NGF.
Collapse
Affiliation(s)
- Dan Duc Pham
- From the Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki, P. O. Box 63, Helsinki FIN-00014, Finland, the Minerva Foundation Institute for Medical Research, Biomedicum-2, Tukholmankatu 8, FIN-00290 Helsinki, Finland
| | - Hai Thi Do
- From the Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki, P. O. Box 63, Helsinki FIN-00014, Finland, the Minerva Foundation Institute for Medical Research, Biomedicum-2, Tukholmankatu 8, FIN-00290 Helsinki, Finland
| | - Céline Bruelle
- From the Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki, P. O. Box 63, Helsinki FIN-00014, Finland, the Minerva Foundation Institute for Medical Research, Biomedicum-2, Tukholmankatu 8, FIN-00290 Helsinki, Finland
| | - Jyrki P Kukkonen
- Biochemistry and Cell Biology, Department of Veterinary Biosciences, P. O. Box 66, University of Helsinki, Helsinki FIN-00014, Finland
| | - Ove Eriksson
- From the Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki, P. O. Box 63, Helsinki FIN-00014, Finland
| | - Isabel Mogollón
- From the Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki, P. O. Box 63, Helsinki FIN-00014, Finland, the Minerva Foundation Institute for Medical Research, Biomedicum-2, Tukholmankatu 8, FIN-00290 Helsinki, Finland
| | - Laura T Korhonen
- From the Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki, P. O. Box 63, Helsinki FIN-00014, Finland, the Minerva Foundation Institute for Medical Research, Biomedicum-2, Tukholmankatu 8, FIN-00290 Helsinki, Finland
| | - Urmas Arumäe
- the Research Program in Developmental Biology, Institute of Biotechnology, University of Helsinki, P. O. Box 65, Helsinki FIN-00014, Finland, and the Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia
| | - Dan Lindholm
- From the Medicum, Department of Biochemistry and Developmental Biology, Medical Faculty, University of Helsinki, P. O. Box 63, Helsinki FIN-00014, Finland, the Minerva Foundation Institute for Medical Research, Biomedicum-2, Tukholmankatu 8, FIN-00290 Helsinki, Finland,
| |
Collapse
|
10
|
Raba M, Palgi J, Lehtivaara M, Arumäe U. Microarray Analysis Reveals Increased Transcriptional Repression and Reduced Metabolic Activity but Not Major Changes in the Core Apoptotic Machinery during Maturation of Sympathetic Neurons. Front Cell Neurosci 2016; 10:66. [PMID: 27013977 PMCID: PMC4792887 DOI: 10.3389/fncel.2016.00066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Accepted: 03/01/2016] [Indexed: 01/19/2023] Open
Abstract
Postnatal maturation of the neurons whose main phenotype and basic synaptic contacts are already established includes neuronal growth, refinement of synaptic contacts, final steps of differentiation, programmed cell death period (PCD) etc. In the sympathetic neurons, postnatal maturation includes permanent end of the PCD that occurs with the same time schedule in vivo and in vitro suggesting that the process could be genetically determined. Also many other changes in the neuronal maturation could be permanent and thus based on stable changes in the genome expression. However, postnatal maturation of the neurons is poorly studied. Here we compared the gene expression profiles of immature and mature sympathetic neurons using Affymetrix microarray assay. We found 1310 significantly up-regulated and 1151 significantly down-regulated genes in the mature neurons. Gene ontology analysis reveals up-regulation of genes related to neuronal differentiation, chromatin and epigenetic changes, extracellular factors and their receptors, and cell adhesion, whereas many down-regulated genes were related to metabolic and biosynthetic processes. We show that termination of PCD is not related to major changes in the expression of classical genes for apoptosis or cell survival. Our dataset is deposited to the ArrayExpress database and is a valuable source to select candidate genes in the studies of neuronal maturation. As an example, we studied the changes in the expression of selected genes Igf2bp3, Coro1A, Zfp57, Dcx, and Apaf1 in the young and mature sympathetic ganglia by quantitative PCR and show that these were strongly downregulated in the mature ganglia.
Collapse
Affiliation(s)
- Mikk Raba
- Department of Gene Technology, Tallinn University of Technology Tallinn, Estonia
| | - Jaan Palgi
- Department of Gene Technology, Tallinn University of Technology Tallinn, Estonia
| | - Maria Lehtivaara
- Biomedicum Functional Genomics Unit, Biomedicum Helsinki, University of Helsinki Helsinki, Finland
| | - Urmas Arumäe
- Department of Gene Technology, Tallinn University of TechnologyTallinn, Estonia; Institute of Biotechnology, University of HelsinkiHelsinki, Finland
| |
Collapse
|
11
|
Garcia-Huerta P, Troncoso-Escudero P, Jerez C, Hetz C, Vidal RL. The intersection between growth factors, autophagy and ER stress: A new target to treat neurodegenerative diseases? Brain Res 2016; 1649:173-180. [PMID: 26993573 DOI: 10.1016/j.brainres.2016.02.052] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 01/25/2016] [Accepted: 02/10/2016] [Indexed: 01/01/2023]
Abstract
One of the salient features of most neurodegenerative diseases is the aggregation of specific proteins in the brain. This proteostasis imbalance is proposed as a key event triggering the neurodegenerative cascade. The unfolded protein response (UPR) and autophagy pathways are emerging as critical processes implicated in handling disease-related misfolded proteins. However, in some conditions, perturbations in the buffering capacity of the proteostasis network may be part of the etiology of the disease. Thus, pharmacological or gene therapy strategies to enhance autophagy or UPR responses are becoming an attractive target for disease intervention. Here, we discuss current evidence depicting the complex involvement of autophagy and ER stress in brain diseases. Novel pathways to modulate protein misfolding are discussed including the relation between aging and growth factor signaling. This article is part of a Special Issue entitled SI:Autophagy.
Collapse
Affiliation(s)
- Paula Garcia-Huerta
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; FONDAP Center for Geroscience, Brain Health and Metabolism, Santiago, Chile; Program of Cellular and Molecular Biology, Center for Molecular Studies of the Cell Institute of Biomedical Sciences, University of Chile, Chile
| | - Paulina Troncoso-Escudero
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; FONDAP Center for Geroscience, Brain Health and Metabolism, Santiago, Chile; Program of Cellular and Molecular Biology, Center for Molecular Studies of the Cell Institute of Biomedical Sciences, University of Chile, Chile
| | - Carolina Jerez
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; FONDAP Center for Geroscience, Brain Health and Metabolism, Santiago, Chile; Neurounion Biomedical Foundation, Santiago, Chile
| | - Claudio Hetz
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; FONDAP Center for Geroscience, Brain Health and Metabolism, Santiago, Chile; Program of Cellular and Molecular Biology, Center for Molecular Studies of the Cell Institute of Biomedical Sciences, University of Chile, Chile; Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA, USA.
| | - Rene L Vidal
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; FONDAP Center for Geroscience, Brain Health and Metabolism, Santiago, Chile; Neurounion Biomedical Foundation, Santiago, Chile.
| |
Collapse
|
12
|
Yamashita T, Abe K. Recent Progress in Therapeutic Strategies for Ischemic Stroke. Cell Transplant 2016; 25:893-8. [PMID: 26786838 DOI: 10.3727/096368916x690548] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Possible strategies for treating stroke include neuroprotection in the acute phase of cerebral ischemia and stem cell therapy in the chronic phase of cerebral ischemia. Previously, we have studied the temporal and spatial expression patterns of c-fos, hypoxia inducible factor-1α (HIF-1α), heat shock protein 70 (HSP70), and annexin V after 90 min of transient middle cerebral occlusion in rats and concluded that there is a time window for neuroprotection from 12 to 48 h after ischemia. In addition, we have estimated the neuroprotective effect of glial cell line-derived neurotrophic factor (GDNF) by injecting Sendai viral vector containing the GDNF gene into the postischemic brain. This Sendai virus-mediated gene transfer of GDNF showed a significant neuroprotective effect in the ischemic brain. Additionally, we have administered GDNF and hepatocyte growth factor (HGF) protein into the postischemic rat brain and estimated the infarct size and antiapoptotic and antiautophagic effects. GDNF and HGF significantly reduced infarct size, the number of microtubule-associated protein 1 light chain 3 (LC3)-positive cells, and the number of terminal deoxynucleotidyl transferase-mediated dUTP-biotin in situ nick-end labeling (TUNEL)-positive cells, indicating that GDNF and HGF were greatly associated with not only the antiapoptotic effect but also the antiautophagic effects. Finally, we have previously transplanted undifferentiated iPSCs into the ipsilateral striatum and cortex at 24 h after cerebral ischemia. Histological analysis was performed at 14 and 28 days after cell transplantation, and we found that iPSCs could supply a great number of doublecortin-positive neuroblasts but also formed tridermal teratoma in the ischemic brain. Our results suggest that iPSCs have a potential to provide neural cells after ischemic brain injury if tumorigenesis is properly controlled. In the future, we will combine these strategies to develop more effective therapies for the treatment of strokes.
Collapse
Affiliation(s)
- Toru Yamashita
- Department of Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | | |
Collapse
|
13
|
GDNF-induced cerebellar toxicity: A brief review. Neurotoxicology 2015; 52:46-56. [PMID: 26535469 DOI: 10.1016/j.neuro.2015.10.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 09/22/2015] [Accepted: 10/24/2015] [Indexed: 12/19/2022]
Abstract
Recombinant-methionyl human glial cell line-derived neurotrophic factor (GDNF) is known for its neurorestorative and neuroprotective effects in rodent and primate models of Parkinson's disease (PD). When administered locally into the putamen of Parkinsonian subjects, early clinical studies showed its potential promise as a disease-modifying agent. However, the development of GDNF for the treatment of PD has been significantly clouded by findings of cerebellar toxicity after continuous intraputamenal high-dose administration in a 6-month treatment/3-month recovery toxicology study in rhesus monkeys. Specifically, multifocal cerebellar Purkinje cell loss affecting 1-21% of the cerebellar cortex was observed in 4 of 15 (26.7%; 95% confidence interval [CI]: 10.5-52.4%) animals treated at the highest dose level tested (3000μg/month). No cerebellar toxicity was observed at lower doses (450 and 900μg/month) in the same study, or at similar or higher doses (up to 10,000μg/month) in subchronic or chronic toxicology studies testing intermittent intracerebroventricular administration. While seemingly associated with the use of GDNF, the pathogenesis of the cerebellar lesions has not been fully understood to date. This review integrates available information to evaluate potential pathogenic mechanisms and provide a consolidated assessment of the findings. While other explanations are considered, the existing evidence is most consistent with the hypothesis that leakage of GDNF into cerebrospinal fluid during chronic infusions into the putamen down-regulates GDNF receptors on Purkinje cells, and that subsequent acute withdrawal of GDNF generates the observed lesions. The implications of these findings for clinical studies with GDNF are discussed.
Collapse
|
14
|
Osman AAM, Dahlin LB, Thomsen NOB, Mohseni S. Autophagy in the posterior interosseous nerve of patients with type 1 and type 2 diabetes mellitus: an ultrastructural study. Diabetologia 2015; 58:625-32. [PMID: 25523623 DOI: 10.1007/s00125-014-3477-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 11/27/2014] [Indexed: 11/30/2022]
Abstract
AIMS/HYPOTHESIS We addressed the question of whether the autophagy pathway occurs in human peripheral nerves and whether this pathway is associated with peripheral neuropathy in diabetes mellitus. METHODS By using electron microscopy, we evaluated the presence of autophagy-related structures and neuropathy in the posterior interosseous nerve of patients who had undergone carpal tunnel release and had type 1 or type 2 diabetes mellitus, and in patients with no diabetes (controls). RESULTS Autophagy-related ultrastructures were observed in the samples taken from all patients of the three groups. The number of autophagy-associated structures was significantly higher (p < 0.05) in the nerves of patients with type 1 than type 2 diabetes. Qualitative and quantitative evaluations of fascicle area, diameter of myelinated and unmyelinated nerve fibres, the density of myelinated and unmyelinated fibres and the g-ratio of myelinated fibres were performed. We found degeneration and regeneration of a few myelinated axons in controls, and a well-developed neuropathy with the loss of large myelinated axons and the presence of many small ones in patients with diabetes. The pathology in type 1 diabetes was more extensive than in type 2 diabetes. CONCLUSIONS/INTERPRETATION The results of this study show that the human peripheral nerves have access to the autophagy machinery, and this pathway may be regulated differently in type 1 and type 2 diabetes; insulin, presence of extensive neuropathy, and/or other factors such as duration of diabetes and HbA1c level may underlie this differential regulation.
Collapse
Affiliation(s)
- Ayman A M Osman
- Department of Clinical and Experimental Medicine, Division of Cell Biology, Linköping University, SE-581 83, Linköping, Sweden
| | | | | | | |
Collapse
|
15
|
Kristiansen M, Ham J. Programmed cell death during neuronal development: the sympathetic neuron model. Cell Death Differ 2014; 21:1025-35. [PMID: 24769728 PMCID: PMC4207485 DOI: 10.1038/cdd.2014.47] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 03/05/2014] [Accepted: 03/13/2014] [Indexed: 01/08/2023] Open
Abstract
Developing sympathetic neurons of the superior cervical ganglion are one of the best studied models of neuronal apoptosis. These cells require nerve growth factor (NGF) for survival at the time that they innervate their final target tissues during late embryonic and early postnatal development. In the absence of NGF, developing sympathetic neurons die by apoptosis in a transcription-dependent manner. Molecular studies of sympathetic neuron apoptosis began in the 1980s. We now know that NGF withdrawal activates the mitochondrial (intrinsic) pathway of apoptosis in sympathetic neurons cultured in vitro, and the roles of caspases, Bcl-2 (B-cell CLL/lymphoma 2) family proteins and XIAP (X-linked inhibitor of apoptosis protein) have been extensively studied. Importantly, a considerable amount has also been learned about the intracellular signalling pathways and transcription factors that regulate programmed cell death in sympathetic neurons. In this article, we review the key papers published in the past few years, covering all aspects of apoptosis regulation in sympathetic neurons and focusing, in particular, on how signalling pathways and transcription factors regulate the cell death programme. We make some comparisons with other models of neuronal apoptosis and describe possible future directions for the field.
Collapse
Affiliation(s)
- M Kristiansen
- Molecular Haematology and Cancer Biology Unit, Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UK
| | - J Ham
- Molecular Haematology and Cancer Biology Unit, Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UK
| |
Collapse
|
16
|
Heermann S, Mätlik K, Hinz U, Fey J, Arumae U, Krieglstein K. Glia cell line-derived neurotrophic factor mediates survival of murine sympathetic precursors. J Neurosci Res 2013; 91:780-5. [PMID: 23426908 DOI: 10.1002/jnr.23188] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 11/12/2012] [Accepted: 11/13/2012] [Indexed: 11/11/2022]
Abstract
During embryonic development, neurons are first produced in excess, and final numbers are adjusted by apoptosis at later stages. Crucial to this end is the amount of target-derived growth factor available for the neurons. By this means, the target size correctly matches the innervating neuron number. This target-derived survival has been well studied for sympathetic neurons, and nerve growth factor (NGF) was identified to be the crucial factor for maintaining sympathetic neurons at late embryonic and early postnatal stages, with a virtual complete loss of sympathetic neurons in NGF knockout (KO) mice. This indicates that all sympathetic neurons are dependent on NGF. However, also different glia cell line-derived neurotrophic factor (GDNF) KO mice consistently presented a loss of sympathetic neurons. This was the rationale for investigating the role of GDNF for sympathetic precursor/neuron survival. Here we show that GDNF is capable of promoting survival of 30% sympathetic precursors dissociated at E13. This is in line with data from GDNF KOs in which a comparable sympathetic neuron loss was observed at late embryonic stages, although the onset of the phenotype was unclear. We further present data showing that GDNF ligand and canonical receptors are expressed in sympathetic neurons especially at embryonic stages, raising the possibility of an autocrine/paracrine GDNF action. Finally, we show that GDNF also maintained neonatal sympathetic neurons (40%) cultured for 2 days. However, the GDNF responsiveness was lost at 5 days in vitro.
Collapse
Affiliation(s)
- Stephan Heermann
- Department of Molecular Embryology Institute of Anatomy and Cell Biology, University of Freiburg, Freiburg, Germany.
| | | | | | | | | | | |
Collapse
|
17
|
Patel AV, Krimm RF. Neurotrophin-4 regulates the survival of gustatory neurons earlier in development using a different mechanism than brain-derived neurotrophic factor. Dev Biol 2012; 365:50-60. [PMID: 22353733 DOI: 10.1016/j.ydbio.2012.02.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 01/31/2012] [Accepted: 02/06/2012] [Indexed: 12/13/2022]
Abstract
The number of neurons in the geniculate ganglion that are available to innervate taste buds is regulated by neurotrophin-4 (NT-4) and brain-derived neurotrophic factor (BDNF). Our goal for the current study was to examine the timing and mechanism of NT-4-mediated regulation of geniculate neuron number during development. We discovered that NT-4 mutant mice lose 33% of their geniculate neuronal cells between E10.5 and E11.5. By E11.5, geniculate axons have just reached the tongue and do not yet innervate their gustatory targets; thus, NT-4 does not function as a target-derived growth factor. At E11.5, no difference was observed in proliferating cells or the rate at which cells exit the cell cycle between NT-4 mutant and wild type ganglia. Instead, there was an increase in TUNEL-labeling, indicating an increase in cell death in Ntf4(-/-) mice compared with wild types. However, activated caspase-3, which is up-regulated in the absence of BDNF, was not increased. This finding indicates that cell death initiated by NT-4-removal occurs through a different cell death pathway than BDNF-removal. We observed no additional postnatal loss of taste buds or neurons in Ntf4(-/-) mice. Thus, during early embryonic development, NT-4 produced in the ganglion and along the projection pathway inhibits cell death through an activated caspase-3 independent mechanism. Therefore, compared to BDNF, NT-4 plays distinct roles in gustatory development; differences include timing, source of neurotrophin, and mechanism of action.
Collapse
Affiliation(s)
- Ami V Patel
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | | |
Collapse
|
18
|
Jakobson M, Lintulahti A, Arumäe U. mRNA for N-Bak, a neuron-specific BH3-only splice isoform of Bak, escapes nonsense-mediated decay and is translationally repressed in the neurons. Cell Death Dis 2012; 3:e269. [PMID: 22297299 PMCID: PMC3288346 DOI: 10.1038/cddis.2012.4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
mRNA for neuronal Bak (N-Bak), a splice variant of pro-apoptotic Bcl-2 family member Bak is expressed in the neurons. Surprisingly the endogeneous N-Bak protein cannot be demonstrated in the neurons, although the antibodies recognize N-Bak protein from in vitro translation or transiently transfected cells. As N-Bak mRNA contains premature termination codon (PTC) at 89 nucleotides upstream from the last exon–exon junction, it could be degraded by nonsense-mediated decay (NMD) during the pioneer round of translation thus explaining the absence of the protein. We show here that the endogeneous neuronal N-Bak mRNA is not the NMD substrate, as it is not accumulating by cycloheximide treatment, it has a long lifetime, and even prevention of PTC by interfering with the alternative splicing did not lead to translation of the Bak mRNA. N-Bak protein is also not revealed by proteasome inhibitors. Our data suggest strong translational arrest of N-Bak mRNA in the neurons. We show that this arrest is partially mediated by 5′-untranslated region of Bak mRNA and it is not released during mitochondrial apoptosis.
Collapse
Affiliation(s)
- M Jakobson
- Institute of Biotechnology, University of Helsinki, FIN-00014 Helsinki, Finland
| | | | | |
Collapse
|
19
|
Duarte FV, Teodoro JS, Rolo AP, Palmeira CM. Exposure to dibenzofuran triggers autophagy in lung cells. Toxicol Lett 2011; 209:35-42. [PMID: 22173198 DOI: 10.1016/j.toxlet.2011.11.029] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 11/27/2011] [Accepted: 11/28/2011] [Indexed: 11/19/2022]
Abstract
Environmental pollutants, such as dioxins and furans, are extremely toxic and related with pulmonary disease development. Exposure of A549 human lung cells to dibenzofuran showed both time- and concentration-dependent decreases in cell proliferation and MTT reduction, but no alterations in cell viability. No differences were observed in the number of apoptotic nuclei, which can be due to the energetic failure caused by dibenzofuran-induced ATP depletion. Moreover, cells in culture exposed to the pollutant showed an increase in the conversion of LC3, a protein involved in the autophagic process. Incubation of A549 lung cells with dibenzofuran caused an increase in Lysotracker Red staining, indicating an increase in lysosomal vacuoles content. These results suggest that exposure to dibenzofuran affects lung mitochondrial phosphorylative function, causing an increase in the population of dysfunctional mitochondria and an impairment in the energetic status maintenance, therefore stimulating autophagy as a possible rescue mechanism in this cell line.
Collapse
Affiliation(s)
- Filipe V Duarte
- CNC - Center for Neurosciences and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
| | | | | | | |
Collapse
|
20
|
Kim WR, Sun W. Programmed cell death during postnatal development of the rodent nervous system. Dev Growth Differ 2011; 53:225-35. [DOI: 10.1111/j.1440-169x.2010.01226.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
21
|
Gomez J, Matsuyama S. Cell-penetrating penta-peptides and Bax-inhibiting peptides: protocol for their application. Methods Mol Biol 2011; 683:465-71. [PMID: 21053150 PMCID: PMC3703514 DOI: 10.1007/978-1-60761-919-2_33] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The first series of cell-penetrating penta-peptides (CPP5s) were discovered as cytoprotective penta-peptides designed from the Bax-inhibiting domain of Ku70. Bax is an inducer of programmed cell death, and Ku70 is a multifunctional protein maintaining genomic stability and protecting cells from death by inhibiting the cytotoxic activity of Bax. Since these peptides bind and inhibit Bax, they are named Bax-inhibiting peptides (BIPs). The second series of CPP5s were developed by mutating BIP's amino acid sequences to abolish the Bax-binding activity. These peptides were used as negative control peptides to evaluate the Bax-inhibiting activity of BIPs. CPP5s are able to enter cells when they are added to the culture medium. The mechanism of cell entry of CPP5s is not yet understood. Numerous studies showed that BIP rescued cells from cytotoxic stresses both in cell culture and animal model, suggesting the therapeutic potential of BIP. Both BIPs and noncytoprotective CPP5s did not show significant toxicity even at 1.6 mM concentration in cell culture. Our recent study suggests that CPP5s has the protein transduction activity, though only green fluorescent protein (GFP) has been tested as a cargo protein. If CPP5s can deliver wide range of cargo molecules into the cell, CPP5s may be utilized as nontoxic drug delivery tool. In this article, we describe our laboratory's protocols of how to synthesize, store, and apply CPP5s for the examination of their activities of cell penetration and cytoprotection.
Collapse
Affiliation(s)
| | - Shigemi Matsuyama
- Correspondence should be addressed to Shigemi Matsuyama TEL: 216-368-5832 (USA),
| |
Collapse
|
22
|
Voutilainen MH, Bäck S, Peränen J, Lindholm P, Raasmaja A, Männistö PT, Saarma M, Tuominen RK. Chronic infusion of CDNF prevents 6-OHDA-induced deficits in a rat model of Parkinson's disease. Exp Neurol 2010; 228:99-108. [PMID: 21185834 DOI: 10.1016/j.expneurol.2010.12.013] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Revised: 12/10/2010] [Accepted: 12/12/2010] [Indexed: 10/18/2022]
Abstract
Cerebral dopamine neurotrophic factor (CDNF) and mesencephalic astrocyte-derived neurotrophic factor (MANF) constitute a novel, evolutionarily conserved family of neurotrophic factors (NTF) expressed in vertebrates and invertebrates. The effects of two-week infusions of CDNF, MANF and glial cell line-derived neurotrophic factor (GDNF) were studied in a rat 6-hydroxydopamine (6-OHDA) hemiparkinsonian model. Degeneration of nigrostriatal dopamine nerve tract after toxin injection was assessed by measuring amphetamine-induced rotational behavior, and at the end of the experiment by quantifying tyrosine hydroxylase (TH)-positive neurons in the substantia nigra pars compacta (SNpc) and TH-positive fibers in the striatum. The diffusion of the NTFs into the brain tissue following chronic infusion was also studied. Finally, we examined the transportation of intrastriatally injected (125)I-CDNF within the brain. The amphetamine-induced rotational behavior was gradually normalized in rats treated with CDNF for two weeks following the intrastriatal 6-OHDA injection. CDNF was also able to inhibit 6-OHDA-induced loss of TH-immunoreactive cells of the SNpc and TH-positive fibers in the striatum. MANF and GDNF had no statistically significant effect in any of the above measures. The volume of distribution for MANF in the striatum was significantly larger than that of GDNF after 3-day infusions. Both (125)I-CDNF and (125)I-GDNF were retrogradely transported from the striatum to the SN. No behavioral signs of toxicity were observed during treatment with the three NTFs. These results imply that CDNF may have potential as a neuroprotective or even neurorestorative therapy of PD.
Collapse
Affiliation(s)
- Merja H Voutilainen
- Division of Pharmacology and Toxicology, Faculty of Pharmacy, P.O. Box 56, Viikki Biocenter, University of Helsinki, FI-00014, Helsinki, Finland
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Hellman M, Arumäe U, Yu LY, Lindholm P, Peränen J, Saarma M, Permi P. Mesencephalic astrocyte-derived neurotrophic factor (MANF) has a unique mechanism to rescue apoptotic neurons. J Biol Chem 2010; 286:2675-80. [PMID: 21047780 DOI: 10.1074/jbc.m110.146738] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mesencephalic astrocyte-derived neurotrophic factor (MANF) protects neurons and repairs the Parkinson disease-like symptoms in a rat 6-hydroxydopamine model. We show a three-dimensional solution structure of human MANF that differs drastically from other neurotrophic factors. Remarkably, the C-terminal domain of MANF (C-MANF) is homologous to the SAP domain of Ku70, a well known inhibitor of proapoptotic Bax (Bcl-2-associated X protein). Cellular studies confirm that MANF and C-MANF protect neurons intracellularly as efficiently as Ku70.
Collapse
Affiliation(s)
- Maarit Hellman
- Program in Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki, FI-00014 Helsinki, Finland
| | | | | | | | | | | | | |
Collapse
|
24
|
Abstract
Dependence receptors form a family of functionally related receptors which are all able to induce two completely opposite intracellular signals depending on the availability of their ligand. Indeed, in its presence, they mediate a positive, classical signal transduction of survival, differentiation or migration but without it, they trigger a negative signal which leads to cell death. The molecular mechanisms involved in triggering cell death in the absence of ligand are starting to be unravelled: dependence receptors are recruited at well-defined domains at the plasma membrane, they trigger cell death through a monomeric form, they are cleaved by caspases and they recruit a caspase activating complex.
Collapse
Affiliation(s)
- Chantal Thibert
- Apoptosis, Cancer and Development Laboratory, Equipe labellisée La Ligue, Université de Lyon, CNRS UMR5238, Lyon, France.
| | | |
Collapse
|
25
|
Bradley LH, Fuqua J, Richardson A, Turchan-Cholewo J, Ai Y, Kelps KA, Glass JD, He X, Zhang Z, Grondin R, Littrell OM, Huettl P, Pomerleau F, Gash DM, Gerhardt GA. Dopamine neuron stimulating actions of a GDNF propeptide. PLoS One 2010; 5:e9752. [PMID: 20305789 PMCID: PMC2841203 DOI: 10.1371/journal.pone.0009752] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Accepted: 02/20/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Neurotrophic factors, such as glial cell line-derived neurotrophic factor (GDNF), have shown great promise for protection and restoration of damaged or dying dopamine neurons in animal models and in some Parkinson's disease (PD) clinical trials. However, the delivery of neurotrophic factors to the brain is difficult due to their large size and poor bio-distribution. In addition, developing more efficacious trophic factors is hampered by the difficulty of synthesis and structural modification. Small molecules with neurotrophic actions that are easy to synthesize and modify to improve bioavailability are needed. METHODS AND FINDINGS Here we present the neurobiological actions of dopamine neuron stimulating peptide-11 (DNSP-11), an 11-mer peptide from the proGDNF domain. In vitro, DNSP-11 supports the survival of fetal mesencephalic neurons, increasing both the number of surviving cells and neuritic outgrowth. In MN9D cells, DNSP-11 protects against dopaminergic neurotoxin 6-hydroxydopamine (6-OHDA)-induced cell death, significantly decreasing TUNEL-positive cells and levels of caspase-3 activity. In vivo, a single injection of DNSP-11 into the normal adult rat substantia nigra is taken up rapidly into neurons and increases resting levels of dopamine and its metabolites for up to 28 days. Of particular note, DNSP-11 significantly improves apomorphine-induced rotational behavior, and increases dopamine and dopamine metabolite tissue levels in the substantia nigra in a rat model of PD. Unlike GDNF, DNSP-11 was found to block staurosporine- and gramicidin-induced cytotoxicity in nutrient-deprived dopaminergic B65 cells, and its neuroprotective effects included preventing the release of cytochrome c from mitochondria. CONCLUSIONS Collectively, these data support that DNSP-11 exhibits potent neurotrophic actions analogous to GDNF, making it a viable candidate for a PD therapeutic. However, it likely signals through pathways that do not directly involve the GFRalpha1 receptor.
Collapse
Affiliation(s)
- Luke H Bradley
- Department of Anatomy & Neurobiology and the Morris K. Udall Parkinson's Disease Research Center of Excellence, University of Kentucky College of Medicine, Lexington, Kentucky, United States of America.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Synergistic effects of osteonectin and NGF in promoting survival and neurite outgrowth of superior cervical ganglion neurons. Brain Res 2009; 1289:1-13. [PMID: 19596278 DOI: 10.1016/j.brainres.2009.06.093] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 06/25/2009] [Accepted: 06/26/2009] [Indexed: 01/01/2023]
Abstract
Schwann cells (SCs) play a major role in the successful regeneration of peripheral nerves regeneration. Here we examined the effects of osteonectin (ON), a major factor secreted by SCs, on survival and neuritogenesis of mouse superior cervical ganglion (SCG) neurons. SC conditioned medium (SCCM) not only promoted the survival and neuritogenesis of SCG neurons at a level comparable to nerve growth factor (NGF) but also doubled the neurite length of NGF-treated SCG neurons. SCCM neuritogenic effects were not blocked by the tyrosine kinase receptor (Trk) inhibitor K252a demonstrating that these are not due solely to classical neurotrophic factors. Anti-ON neutralizing antibody diminished the SCCM-induced survival and neuritogenesis significantly. In the presence of K252a, the SCCM neuritogenic effects were blocked completely by anti-ON which suggests synergistic effects of ON with Trk-mediated growth factors. ON alone increased the survival and neurite outgrowth of SCG neurons significantly at high density cultures. ON at low concentration acts synergistically with NGF which induced maximum survival and neurite outgrowth (>50% increase). However, ON at high concentration was detrimental to survival (64% decrease) and neurite outgrowth (87% decrease) even in the presence of NGF. The well documented counter-adhesive effect of ON may account for this observation. Nevertheless, the growth promoting effects of ON became more pronounced as the cell density increased which suggests a possible interaction of ON with growth factors secreted by SCG neurons (autocrine or paracrine effects). Taken together, our study indicates that ON plays important roles in nervous system repair through its synergistic effects with growth factors.
Collapse
|
27
|
Oxidative modifications, mitochondrial dysfunction, and impaired protein degradation in Parkinson's disease: how neurons are lost in the Bermuda triangle. Mol Neurodegener 2009; 4:24. [PMID: 19500376 PMCID: PMC2701947 DOI: 10.1186/1750-1326-4-24] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Accepted: 06/05/2009] [Indexed: 12/21/2022] Open
Abstract
While numerous hypotheses have been proposed to explain the molecular mechanisms underlying the pathogenesis of neurodegenerative diseases, the theory of oxidative stress has received considerable support. Although many correlations have been established and encouraging evidence has been obtained, conclusive proof of causation for the oxidative stress hypothesis is lacking and potential cures have not emerged. Therefore it is likely that other factors, possibly in coordination with oxidative stress, contribute to neuron death. Using Parkinson's disease (PD) as the paradigm, this review explores the hypothesis that oxidative modifications, mitochondrial functional disruption, and impairment of protein degradation constitute three interrelated molecular pathways that execute neuron death. These intertwined events are the consequence of environmental exposure, genetic factors, and endogenous risks and constitute a "Bermuda triangle" that may be considered the underlying cause of neurodegenerative pathogenesis.
Collapse
|
28
|
Gama V, Gomez JA, Mayo LD, Jackson MW, Danielpour D, Song K, Haas AL, Laughlin MJ, Matsuyama S. Hdm2 is a ubiquitin ligase of Ku70-Akt promotes cell survival by inhibiting Hdm2-dependent Ku70 destabilization. Cell Death Differ 2009; 16:758-69. [PMID: 19247369 PMCID: PMC2669846 DOI: 10.1038/cdd.2009.6] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Earlier, we have reported that 70 kDa subunit of Ku protein heterodimer (Ku70) binds and inhibits Bax activity in the cytosol and that ubiquitin (Ub)-dependent proteolysis of cytosolic Ku70 facilitates Bax-mediated apoptosis. We found that Hdm2 (human homolog of murine double minute) has an ability to ubiquitinate Ku70 and that Hdm2 overexpression in cultured cells causes a decrease in Ku70 expression levels. An interaction between Ku70 and Hdm2 was shown by means of immunoprecipitation, whereas none could be shown between 80 kDa subunit of Ku protein heterodimer and Hdm2. Vascular endothelial growth factor (VEGF) is known to inhibit endothelial cell (EC) apoptosis through an Akt-mediated survival kinase signal; however, the mechanism underlying this inhibition of apoptosis has not been fully elucidated. We found that VEGF inhibited cytosolic Ku70 degradation induced by apoptotic stress. It is known that Akt-dependent phosphorylation of Hdm2 causes nuclear translocation of Hdm2 followed by Hdm2-mediated inactivation of p53. We found that VEGF stimulated nuclear translocation of Hdm2 in EC and efficiently inhibited Ku70 degradation. We also found that constitutively active Akt, but not kinase-dead Akt, inhibited Ku70 degradation in the cytosol. Furthermore, Ku70 knockdown diminished antiapoptotic activity of Akt. Taken together, we propose that Hdm2 is a Ku70 Ub ligase and that Akt inhibits Bax-mediated apoptosis, at least in part, by maintaining Ku70 levels through the promotion of Hdm2 nuclear translocation.
Collapse
Affiliation(s)
- Vivian Gama
- Department of Medicine (Division of Hematology-Oncology), Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106
- Department of Pharmacology, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106
| | - Jose A. Gomez
- Department of Medicine (Division of Hematology-Oncology), Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106
- Department of Pharmacology, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106
| | - Lindsey D. Mayo
- Department of Pediatrics, Herman B. Wells Center for Pediatrics Research, Melvin and Bren Simon Cancer Center, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Mark W. Jackson
- Department of Pathology, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106
- Division of General Medical Science-Oncology, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106
| | - David Danielpour
- Department of Pharmacology, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106
- Division of General Medical Science-Oncology, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106
| | - Kyung Song
- Department of Pharmacology, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106
- Division of General Medical Science-Oncology, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106
| | - Arthur L. Haas
- Department of Biochemistry and Molecular Biology, Louisiana State University School of Medicine, New Orleans, LA 70112
| | - Mary J. Laughlin
- Department of Medicine (Division of Hematology-Oncology), Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106
- Division of General Medical Science-Oncology, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106
| | - Shigemi Matsuyama
- Department of Medicine (Division of Hematology-Oncology), Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106
- Department of Pharmacology, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106
- Division of General Medical Science-Oncology, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106
| |
Collapse
|
29
|
Death receptors and caspases but not mitochondria are activated in the GDNF- or BDNF-deprived dopaminergic neurons. J Neurosci 2008; 28:7467-75. [PMID: 18650325 DOI: 10.1523/jneurosci.1877-08.2008] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Neurotrophic factors, including glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF), promote survival of midbrain dopaminergic neurons, but the death pathways activated in the dopaminergic neurons by deprivation of these factors are poorly studied. We show here that deprivation of GDNF or BDNF triggers a novel mitochondria-independent death pathway in the cultured embryonic dopaminergic neurons: cytochrome c was not released from the mitochondria to cytosol, proapoptotic protein Bax was not activated, and overexpressed Bcl-xL did not block the death. Caspases were critically required, because the death was completely blocked by caspase inhibitor BAF [boc-aspartyl(OMe)-fluoromethylketone] and overexpression of dominant-negative mutants of caspase-9, -3, and -7 significantly blocked the death. Also, the death receptor pathway was involved, because blockage of caspase-8 or FADD (Fas-associated protein with death domain), an adapter required for caspase-8 activation, inhibited death induced by GDNF or BDNF deprivation. Ligation of Fas by agonistic anti-Fas antibody induced apoptosis in the GDNF- or BDNF-maintained neurons, and inhibition of Fas by Fas-Fc chimera blocked the death of GDNF- or BDNF-deprived neurons, whereas FAIM(L) (long isoform of Fas apoptosis inhibitory molecule) could control the activity of Fas in the dopaminergic neurons.
Collapse
|
30
|
Korhonen L, Hansson I, Maugras C, Wehrle R, Kairisalo M, Borgkvist A, Jokitalo E, Sotelo C, Fisone G, Dusart I, Lindholm D. Expression of X-chromosome linked inhibitor of apoptosis protein in mature Purkinje cells and in retinal bipolar cells in transgenic mice induces neurodegeneration. Neuroscience 2008; 156:515-26. [PMID: 18765270 DOI: 10.1016/j.neuroscience.2008.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2008] [Revised: 08/04/2008] [Accepted: 08/05/2008] [Indexed: 11/28/2022]
Abstract
Transgenic mice with overexpression of the caspase-inhibitor, X-chromosome-linked inhibitor of apoptosis protein (XIAP) in Purkinje cell (PC) and in retinal bipolar cells (RBCs) were produced to study the regulation of cell death. Unexpectedly, an increased neurodegeneration was observed in the PCs in these L7-XIAP mice after the third postnatal week with the mice exhibiting severe ataxia. The loss of PCs was independent of Bax as shown by crossing the L7-XIAP mice with Bax gene-deleted mice. Electron microscopy revealed intact organelles in PCs but with the stacking of ER cisterns indicative of cell stress. Immunostaining for cell death proteins showed an increased phosphorylation of c-Jun in the PCs, suggesting an involvement in cell degeneration. Apart from PCs, the number of RBCs was decreased in adult retina in line with the expression pattern for the L7 promoter. The data show that overexpression of the anti-apoptotic protein XIAP in vulnerable neurons leads to enhanced cell death. The mechanisms underlying this neurodegeneration can be related to the effects of XIAP on cell stress and altered cell signaling.
Collapse
Affiliation(s)
- L Korhonen
- Minerva Medical Research Institute, Biomedicum-2U Helsinki, Tukholmankatu 8, FIN-00290 Helsinki, Finland
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Stewart AL, Anderson RB, Kobayashi K, Young HM. Effects of NGF, NT-3 and GDNF family members on neurite outgrowth and migration from pelvic ganglia from embryonic and newborn mice. BMC DEVELOPMENTAL BIOLOGY 2008; 8:73. [PMID: 18657279 PMCID: PMC2515305 DOI: 10.1186/1471-213x-8-73] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2008] [Accepted: 07/25/2008] [Indexed: 01/09/2023]
Abstract
Background Pelvic ganglia are derived from the sacral neural crest and contain both sympathetic and parasympathetic neurons. Various members of the neurotrophin and GDNF families of neurotrophic factors have been shown to play important roles in the development of a variety of peripheral sympathetic and parasympathetic neurons; however, to date, the role of these factors in the development of pelvic ganglia has been limited to postnatal and older ages. We examined the effects of NGF, NT-3, GDNF, neurturin and artemin on cell migration and neurite outgrowth from explants of the pelvic ganglia from embryonic and newborn mice grown on collagen gels, and correlated the responses with the immunohistochemical localization of the relevant receptors in fixed tissue. Results Cell migration assays showed that GDNF strongly stimulated migration of tyrosine hydroxylase (TH) cells of pelvic ganglia from E11.5, E14.5 and P0 mice. Other factors also promoted TH cell migration, although to a lesser extent and only at discrete developmental stages. The cells and neurites of the pelvic ganglia were responsive to each of the GDNF family ligands – GDNF, neurturin and artemin – from E11.5 onwards. In contrast, NGF and NT-3 did not elicit a significant neurite outgrowth effect until E14.5 onwards. Artemin and NGF promoted significant outgrowth of sympathetic (TH+) neurites only, whereas neurturin affected primarily parasympathetic (TH-negative) neurite outgrowth, and GDNF and NT-3 enhanced both sympathetic and parasympathetic neurite outgrowth. In comparison, collagen gel assays using gut explants from E11.5 and E14.5 mice showed neurite outgrowth only in response to GDNF at E11.5 and to neurturin only in E14.5 mice. Conclusion Our data show that there are both age-dependent and neuron type-dependent differences in the responsiveness of embryonic and neo-natal pelvic ganglion neurons to growth factors.
Collapse
Affiliation(s)
- Ashley L Stewart
- Department of Anatomy and Cell Biology, University of Melbourne, 3010, Australia.
| | | | | | | |
Collapse
|
32
|
Tasdemir E, Galluzzi L, Maiuri MC, Criollo A, Vitale I, Hangen E, Modjtahedi N, Kroemer G. Methods for assessing autophagy and autophagic cell death. Methods Mol Biol 2008; 445:29-76. [PMID: 18425442 DOI: 10.1007/978-1-59745-157-4_3] [Citation(s) in RCA: 149] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Autophagic (or type 2) cell death is characterized by the massive accumulation of autophagic vacuoles (autophagosomes) in the cytoplasm of cells that lack signs of apoptosis (type 1 cell death). Here we detail and critically assess a series of methods to promote and inhibit autophagy via pharmacological and genetic manipulations. We also review the techniques currently available to detect autophagy, including transmission electron microscopy, half-life assessments of long-lived proteins, detection of LC3 maturation/aggregation, fluorescence microscopy, and colocalization of mitochondrion- or endoplasmic reticulum-specific markers with lysosomal proteins. Massive autophagic vacuolization may cause cellular stress and represent a frustrated attempt of adaptation. In this case, cell death occurs with (or in spite of) autophagy. When cell death occurs through autophagy, on the contrary, the inhibition of the autophagic process should prevent cellular demise. Accordingly, we describe a strategy for discriminating cell death with autophagy from cell death through autophagy.
Collapse
Affiliation(s)
- Ezgi Tasdemir
- INSERM, Unit Apoptosis, Cancer and Immunity, Villejuif, France
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Lang-Rollin I, Dermentzaki G, Vekrellis K, Xilouri M, Rideout HJ, Stefanis L. A novel cell death pathway that is partially caspase dependent, but morphologically non-apoptotic, elicited by proteasomal inhibition of rat sympathetic neurons. J Neurochem 2008; 105:653-65. [DOI: 10.1111/j.1471-4159.2007.05165.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
34
|
Uesaka T, Jain S, Yonemura S, Uchiyama Y, Milbrandt J, Enomoto H. Conditional ablation of GFRalpha1 in postmigratory enteric neurons triggers unconventional neuronal death in the colon and causes a Hirschsprung's disease phenotype. Development 2008; 134:2171-81. [PMID: 17507417 DOI: 10.1242/dev.001388] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The regulation of neuronal survival and death by neurotrophic factors plays a central role in the sculpting of the nervous system, but the identity of survival signals for developing enteric neurons remains obscure. We demonstrate here that conditional ablation of GFRalpha1, the high affinity receptor for GDNF, in mice during late gestation induces rapid and widespread neuronal death in the colon, leading to colon aganglionosis reminiscent of Hirschsprung's disease. Enteric neuron death induced by GFRalpha1 inactivation is not associated with the activation of common cell death executors, caspase-3 or -7, and lacks the morphological hallmarks of apoptosis, such as chromatin compaction and mitochondrial pathology. Consistent with these in vivo observations, neither caspase inhibition nor Bax deficiency blocks death of colon-derived enteric neurons induced by GDNF deprivation. This study reveals an essential role for GFRalpha1 in the survival of enteric neurons and suggests that caspase-independent death can be triggered by abolition of neurotrophic signals.
Collapse
Affiliation(s)
- Toshihiro Uesaka
- Laboratory for Neuronal Differentiation and Regeneration, RIKEN Center for Developmental Biology, Kobe 650-0047, Japan
| | | | | | | | | | | |
Collapse
|
35
|
Kim SY, Kim H, Sun W. Selective suppression of a subset of Bax‐dependent neuronal death by a cell permeable peptide inhibitor of Bax, BIP. Anim Cells Syst (Seoul) 2008. [DOI: 10.1080/19768354.2008.9647175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
|
36
|
Yu LY, Arumäe U. Survival assay of transiently transfected dopaminergic neurons. J Neurosci Methods 2007; 169:8-15. [PMID: 18191457 DOI: 10.1016/j.jneumeth.2007.11.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Revised: 11/14/2007] [Accepted: 11/16/2007] [Indexed: 11/16/2022]
Abstract
Death pathways in the apoptotic neurons are mostly studied by manipulating the levels of apoptosis-related proteins and counting the survival/death of affected neurons. Such assays are, however, technically complicated. We developed a transfection-survival assay for cultured embryonic dopaminergic (DA) neurons induced to die by deprivation of glial cell line-derived neurotrophic factor (GDNF). The calcium phosphate co-precipitation technique was used to transfect DA neurons. Microisland cultures and co-transfected enhanced green fluorescent protein allowed direct counting of transfected neurons from the same cultures at the beginning and the end of GDNF deprivation, whereas post hoc subtraction of tyrosine hydroxylase-negative neurons allowed exclusion of transfected non-DA neurons. Overexpression of dominant-negative mutant of caspase-6 significantly blocked the death of GDNF-deprived DA neurons. Thus, we have found a tool not only to transfect the neurons dissociated from midbrain, but also to analyze the apoptotic proteins particularly in DA neurons.
Collapse
Affiliation(s)
- Li-Ying Yu
- Institute of Biotechnology, University of Helsinki, FIN-00014, Helsinki, Finland
| | | |
Collapse
|
37
|
Gomez JA, Gama V, Yoshida T, Sun W, Hayes P, Leskov K, Boothman D, Matsuyama S. Bax-inhibiting peptides derived from Ku70 and cell-penetrating pentapeptides. Biochem Soc Trans 2007; 35:797-801. [PMID: 17635151 DOI: 10.1042/bst0350797] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We found that Ku70, a known DNA repair factor, has a novel function to bind and inhibit Bax (Bcl-2-associated X protein), a key mediator of apoptosis. Pentapeptides derived from the Bax-binding domain of Ku70 were cell-permeable and protected cells from Bax-mediated apoptosis. These pentapeptides were called BIPs (Bax-inhibiting peptides). BIPs may become a useful therapeutic tool to reduce cellular damage. We also generated BIP mutant pentapeptides that do not inhibit Bax, but retain their cell-penetrating activity. Since both BIPs and BIP mutants are cell-permeable, these peptides were designated CPP5s (cell-penetrating pentapeptides). Among the CPP5s discovered, VPTLK (BIP) and KLPVM (BIP mutant) were confirmed to possess protein transduction activity by examination of the delivery of GFP (green fluorescent protein) into cells by these peptides. The mechanism of cell penetration by CPP5s is not known. CPP5s enter the cell at 0 and 4 degrees C. In preliminary studies, various inhibitors of endocytosis and pinocytosis did not show any significant suppression of CPP5 cell entry. CPP5s have very low toxicity in vitro and in vivo and so may be useful tools in order to develop non-toxic drug-delivery technologies.
Collapse
Affiliation(s)
- J A Gomez
- Pharmacology Department, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Tauszig-Delamasure S, Yu LY, Cabrera JR, Bouzas-Rodriguez J, Mermet-Bouvier C, Guix C, Bordeaux MC, Arumäe U, Mehlen P. The TrkC receptor induces apoptosis when the dependence receptor notion meets the neurotrophin paradigm. Proc Natl Acad Sci U S A 2007; 104:13361-6. [PMID: 17686986 PMCID: PMC1948910 DOI: 10.1073/pnas.0701243104] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The TrkC/NT-3 receptor/ligand pair is believed to be part of the classic neurotrophic theory claiming that neuronal death occurs by default when neurotrophic factors become limited, through loss of survival signals. Here, we show that TrkC is a dependence receptor and, as such, induces caspase-dependent apoptotic death in the absence of NT-3 in immortalized cells, a proapoptotic activity inhibited by the presence of NT-3. This proapoptotic activity of TrkC relies on the caspase-mediated cleavage of the intracellular domain of TrkC, which permits the release of a proapoptotic fragment. This fragment induces apoptosis through a caspase-9-dependent mechanism. Finally, we show that the death of dorsal root ganglion (DRG) neurons provoked by NT-3 withdrawal is inhibited when TrkC-proapoptotic activity is antagonized. Thus, the death of neurons upon disappearance of NT-3 is not only due to a loss of survival signals but also to the active proapoptotic activity of the unbound TrkC dependence receptor.
Collapse
Affiliation(s)
- Servane Tauszig-Delamasure
- *Apoptosis, Cancer and Development Laboratory, Equipe Labellisée La Ligue, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5238, Université de Lyon, Centre Léon Bérard, 69008 Lyon, France; and
| | - Li-Ying Yu
- Research Program in Molecular Neurobiology, University of Helsinki, P.O. Box 56, Viikki Biocenter, FIN-00014, Helsinki, Finland
| | - Jorge Ruben Cabrera
- *Apoptosis, Cancer and Development Laboratory, Equipe Labellisée La Ligue, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5238, Université de Lyon, Centre Léon Bérard, 69008 Lyon, France; and
| | - Jimena Bouzas-Rodriguez
- *Apoptosis, Cancer and Development Laboratory, Equipe Labellisée La Ligue, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5238, Université de Lyon, Centre Léon Bérard, 69008 Lyon, France; and
| | - Catherine Mermet-Bouvier
- *Apoptosis, Cancer and Development Laboratory, Equipe Labellisée La Ligue, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5238, Université de Lyon, Centre Léon Bérard, 69008 Lyon, France; and
| | - Catherine Guix
- *Apoptosis, Cancer and Development Laboratory, Equipe Labellisée La Ligue, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5238, Université de Lyon, Centre Léon Bérard, 69008 Lyon, France; and
| | - Marie-Claire Bordeaux
- *Apoptosis, Cancer and Development Laboratory, Equipe Labellisée La Ligue, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5238, Université de Lyon, Centre Léon Bérard, 69008 Lyon, France; and
| | - Urmas Arumäe
- Research Program in Molecular Neurobiology, University of Helsinki, P.O. Box 56, Viikki Biocenter, FIN-00014, Helsinki, Finland
| | - Patrick Mehlen
- *Apoptosis, Cancer and Development Laboratory, Equipe Labellisée La Ligue, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5238, Université de Lyon, Centre Léon Bérard, 69008 Lyon, France; and
- To whom correspondence should be addressed. E-mail:
| |
Collapse
|
39
|
Benítez JA, Arregui L, Vergara P, Segovia J. Targeted-simultaneous expression of Gas1 and p53 using a bicistronic adenoviral vector in gliomas. Cancer Gene Ther 2007; 14:836-46. [PMID: 17599090 DOI: 10.1038/sj.cgt.7701076] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The targeted expression of transgenes is one of the principal goals of gene therapy, and it is particularly relevant for the treatment of brain tumors. In this study, we examined the effect of the overexpression of human gas1 (growth arrest specific 1) and human p53 cDNAs, both under the transcriptional control of a promoter of the human glial fibrillary acidic protein (gfa2), employing adenoviral expression vectors, in glioma cells. We showed that the targeted overexpression of gas1 and p53 (AdSGas1 and AdSp53, respectively) in rat glioma cells (C6) reduced the number of viable cells and induced apoptosis. Moreover, the adenovirally targeted expression of these genes also reduced tumor growth in vivo. Unexpectedly, there was no additive effect when both gas1 and p53 were simultaneously expressed in the same cells using a bicistronic adenoviral vector. We suggest that Gas1 does not act in combination with p53 in the C6 and U373 glioma cell lines, inducing apoptosis and cell cycle arrest. Our results indicate that the targeted expression of tumor suppressor genes (gas1 and p53) regulated by the gfa2 promoter, together with adenoviral vectors may provide an interesting approach for adjuvant selective glioma gene therapy.
Collapse
Affiliation(s)
- J A Benítez
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, México DF, México
| | | | | | | |
Collapse
|
40
|
Brunet N, Tarabal O, Portero-Otín M, Oppenheim RW, Esquerda JE, Calderó J. Survival and death of mature avian motoneurons in organotypic slice culture: trophic requirements for survival and different types of degeneration. J Comp Neurol 2007; 501:669-90. [PMID: 17299760 DOI: 10.1002/cne.21157] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have developed an organotypic culture technique that uses slices of chick embryo spinal cord, in which trophic requirements for long-term survival of mature motoneurons (MNs) were studied. Slices were obtained from E16 chick embryos and maintained for up to 28 days in vitro (DIV) in a basal medium. Under these conditions, most MNs died. To promote MN survival, 14 different trophic factors were assayed. Among these 14, glial cell line-derived neurotrophic factor (GDNF) and vascular endothelial growth factor were the most effective. GDNF was able to promote MN survival for at least 28 DIV. K(+) depolarization or caspase inhibition prevented MN death but also induced degenerative-like changes in rescued MNs. Agents that elevate cAMP levels promoted the survival of a proportion of MNs for at least 7 DIV. Examination of dying MNs revealed that, in addition to cells exhibiting a caspase-3-dependent apoptotic pattern, some MNs died by a caspase-3-independent mechanism and displayed autophagic vacuoles, an extremely convoluted nucleus, and a close association with microglia. This organotypic spinal cord slice culture may provide a convenient model for testing conditions that promote survival of mature-like MNs that are affected in late-onset MN disease such as amyotrophic lateral sclerosis.
Collapse
Affiliation(s)
- Núria Brunet
- Unitat de Neurobiologia Cel.lular, Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida and IRB Lleida, 25008 Lleida, Catalonia, Spain
| | | | | | | | | | | |
Collapse
|
41
|
Almeida-Leite CMD, Galvão LMDC, Afonso LCC, Cunha FDQ, Arantes RME. Interferon-γ induced nitric oxide mediates in vitro neuronal damage by Trypanosoma cruzi-infected macrophages. Neurobiol Dis 2007; 25:170-8. [PMID: 17056264 DOI: 10.1016/j.nbd.2006.09.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Revised: 09/01/2006] [Accepted: 09/05/2006] [Indexed: 11/21/2022] Open
Abstract
Neuronal lesions and peripheral denervation in Chagas' disease are related to local inflammation; however, the pathogenic mechanisms of neuronal lesions in the heart and megavisceras are still unclear. We investigated the involvement of nitric oxide (NO) on neuronal lesion in co-cultures of neurons and macrophages. Trypanosoma cruzi-infected and interferon-gamma (IFN-gamma)-activated co-cultures of neurons and wild-type (WT) macrophages showed significant reduction of both neuronal survival and neurite density. These findings correlated with the levels of NO and the expression of inducible nitric oxide synthase (iNOS). Accordingly, neuronal survival rate in the co-cultures was recovered to control levels by treatment of the cultures with the iNOS inhibitor, aminoguanidine. Moreover, neither neuronal survival nor the neurite density was affected in the co-cultures when the macrophages were harvested from iNOS-deficient mice. These results demonstrate that iNOS-derived NO is the major molecule involved in neuronal damage mechanism in our in vitro model of Chagas' disease neuropathology.
Collapse
Affiliation(s)
- Camila Megale de Almeida-Leite
- Department of Pathology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | | | | | | |
Collapse
|
42
|
Abstract
Macroautophagy, a lysosomal pathway responsible for the turnover of organelles and long-lived proteins, has been regarded mainly as an inducible process in neurons, which is mobilized in states of stress and injury. New studies show, however, that macroautophagy is also constitutively active in healthy neurons and is vital to cell survival. Neurons in the brain, unlike cells in the periphery, are protected from large-scale autophagy induction because they can use several different energy sources optimally, receive additional nutrients and neurotrophin support from glial cells, and benefit from hypothalamic regulation of peripheral nutrient supplies. Due to its exceptional efficiency, constitutive autophagy in healthy neurons proceeds in the absence of easily detectable autophagic vacuole intermediates. These intermediates can accumulate rapidly, however, when late steps in the autophagic process are blocked. Autophagic vacuoles also accumulate abnormally in affected neurons of several major neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease, where they have been linked to various aspects of disease pathogenesis including neuronal cell death. The build-up of autophagic vacuoles in these neurological disorders and others may reflect either heightened autophagy induction, impairment in later digestive steps in the autophagy pathway, or both. Determining the basis for AV accumulation is critical for understanding the pathogenic significance of autophagy in a given pathologic state and for designing possible therapies based on modulating autophagy. In this review, we discuss the special features of autophagy regulation in the brain, its suspected roles in neurodevelopment and plasticity, and recent progress toward understanding how dysfunctional autophagy contributes to neurodegenerative disease.
Collapse
Affiliation(s)
- Barry Boland
- Department of Pharmacology, Oxford University, Oxford OX13QT, United Kingdom
| | | |
Collapse
|
43
|
Wright KM, Vaughn AE, Deshmukh M. Apoptosome dependent caspase-3 activation pathway is non-redundant and necessary for apoptosis in sympathetic neurons. Cell Death Differ 2006; 14:625-33. [PMID: 16932756 DOI: 10.1038/sj.cdd.4402024] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Although sympathetic neurons are a well-studied model for neuronal apoptosis, the role of the apoptosome in activating caspases in these neurons remains debated. We find that the ability of sympathetic neurons to undergo apoptosis in response to nerve growth factor (NGF) deprivation is completely dependent on having an intact apoptosome pathway. Genetic deletion of Apaf-1, caspase-9, or caspase-3 prevents apoptosis after NGF deprivation, and importantly, allows these neurons to recover and survive long-term following readdition of NGF. The inability of caspase-3 deficient sympathetic neurons to undergo apoptosis is particularly striking, as apoptosis in dermal fibroblasts and cortical neurons proceeds even in the absence of caspase-3. Our results show that in contrast to dermal fibroblasts and cortical neurons, sympathetic neurons express no detectable levels of caspase-7. The strict requirement for an intact apoptosome, coupled with a lack of effector caspase redundancy, provides sympathetic neurons with a markedly increased control over their apoptotic pathway.
Collapse
Affiliation(s)
- K M Wright
- Curriculum in Neurobiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | | | | |
Collapse
|
44
|
Leinninger GM, Backus C, Sastry AM, Yi YB, Wang CW, Feldman EL. Mitochondria in DRG neurons undergo hyperglycemic mediated injury through Bim, Bax and the fission protein Drp1. Neurobiol Dis 2006; 23:11-22. [PMID: 16684605 DOI: 10.1016/j.nbd.2006.01.017] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2005] [Revised: 01/13/2006] [Accepted: 01/27/2006] [Indexed: 11/21/2022] Open
Abstract
Dorsal root ganglia (DRG) neurons degenerate in diabetic neuropathy (DN) and exhibit mitochondrial damage. We studied mitochondria of cultured DRG neurons exposed to high glucose as an in vitro model of DN. High glucose sequentially increases the expression, activation and localization of the pro-apoptotic proteins Bim and Bax and the mitochondrial fission protein dynamin-regulated protein 1 (Drp1). High glucose causes association of Drp1/Bax, similar to other apoptotic stimuli. Collectively, these events promote mitochondrial fragmentation and reduce mitochondrial number, suggestive of apoptotic mitochondrial fission. Drp1 is also upregulated in DRG from experimentally diabetic rats, suggesting a role for mitochondrial fission in DN. Insulin-like growth factor-I (IGF-I) protects high glucose-treated DRG neurons by preventing mitochondrial accumulation of Bim and Bax but does not modulate Drp1 expression or localization. We propose that mitochondria are compromised by convergence of Bim/Bax proteins with Drp1, which contributes to high glucose-induced injury in DRG neurons.
Collapse
Affiliation(s)
- Gina M Leinninger
- Neuroscience Program, University of Michigan, Ann Arbor, MI 48109, USA
| | | | | | | | | | | |
Collapse
|
45
|
Arimochi H, Morita K. Characterization of cytotoxic actions of tricyclic antidepressants on human HT29 colon carcinoma cells. Eur J Pharmacol 2006; 541:17-23. [PMID: 16753142 DOI: 10.1016/j.ejphar.2006.04.053] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2005] [Revised: 04/20/2006] [Accepted: 04/28/2006] [Indexed: 12/15/2022]
Abstract
Preclinical studies have suggested that the long-term use of antidepressants may result in the initiation and/or promotion of tumor in the gastrointestinal tract. However, a possible relationship between the use of antidepressants and the production of colon cancer has not yet been confirmed, and hence requires to be further investigated. To address this issue, the effects of antidepressants on the proliferation of colorectal tumor cells were examined using human HT29 colon carcinoma cells, and tricyclic antidepressant, such as imipramine, desipramine and amitriptyline, were shown to reduce the cell viability in a manner dependent on the time exposing to these drugs. In addition to these drugs, a selective serotonin reuptake inhibitor fluoxetine, but not a monoamine oxidase inhibitor tranylcypromine, caused the reduction of cell viability, similar in extent to that caused by imipramine. Further studies showed that desipramine caused the apoptotic cell death, which could be prevented by neither catalase, reduced-form glutathione (GSH), nor N-acetylcysteine (NAC), without accompanying the disruption of mitochondrial membrane potential within the cells and the release of cytochrome c into the cell cytoplasm. Moreover, desipramine caused the arrest of cell-cycle progression at either G0/G1-phase or G2/M-phase, which might be depending upon the drug concentration. Thus, these results suggest that tricyclic antidepressants may be cytotoxic, and induce the non-oxidative apoptotic death of human HT29 colon carcinoma cells probably through a non-mitochondrial pathway associated with the cell-cycle progression.
Collapse
Affiliation(s)
- Hideki Arimochi
- Department of Molecular Bacteriology, Tokushima University School of Medicine, 3-18-15 Kuramoto, Tokushima 770-8503, Japan
| | | |
Collapse
|
46
|
Abstract
Autophagy is the regulated process by which cytoplasmic organelles and long-lived proteins are delivered for lysosomal degradation. Increased numbers of autophagosomes and autolysosomes often represent prominent ultrastructural features of degenerating or dying neurons. This morphology is characteristic not only of neurons undergoing pathologic degeneration, but also during developmental programmed cell death of some neuronal populations. In recent years, a growing number of reports highlight potentially important roles for autophagy-related processes in relation to protein aggregation, regulated cell death pathways, and neurodegeneration. While starvation-induced autophagy involves nonselective bulk degradation of cytoplasm, mechanisms that regulate selective targeting of damaged organelles form an emerging area. As the study of autophagy evolves from physiologic homeostasis to pathologic situations, consideration of terminology and definitions becomes important. Increased autophagic vacuoles do not necessarily correlate with increased autophagic activity or flux. Instead, the striking accumulation of autophagic vacuoles in dying or degenerating neurons likely reflects an imbalance between the rates of autophagic sequestration and completion of the degradative process. In other words, these cells can be thought of as undergoing "autophagic stress." The concept of autophagic stress may reconcile apparently conflicting roles of autophagy-related processes in adaptive, homeostatic responses and in pathways of neurodegeneration and cell death.
Collapse
Affiliation(s)
- Charleen T Chu
- Department of Pathology/Division of Neuropathology, Department of Ophthalmology, Center for Neuroscience (CNUP), Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pennsylvania, USA.
| |
Collapse
|
47
|
Gama V, Yoshida T, Gomez JA, Basile DP, Mayo LD, Haas AL, Matsuyama S. Involvement of the ubiquitin pathway in decreasing Ku70 levels in response to drug-induced apoptosis. Exp Cell Res 2006; 312:488-99. [PMID: 16368436 DOI: 10.1016/j.yexcr.2005.11.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2005] [Revised: 11/09/2005] [Accepted: 11/10/2005] [Indexed: 11/19/2022]
Abstract
Ku70 plays an important role in DNA damage repair and prevention of cell death. Previously, we reported that apoptosis caused a decrease in cellular Ku70 levels. In this study, we analyzed the mechanism of how Ku70 levels decrease during drug-induced apoptosis. In HeLa cells, staurosporin (STS) caused a decrease in Ku70 levels without significantly affecting Ku70 mRNA levels. We found that Ku70 protein was highly ubiquitinated in various cell types, such as HeLa, HEK293T, Dami (a megakaryocytic cell line), endothelial, and rat kidney cells. An increase in ubiquitinated Ku70 protein was observed in apoptotic cells, and proteasome inhibitors attenuated the decrease in Ku70 levels in apoptotic cells. These results suggest that the ubiquitin-proteasome proteolytic pathway plays a role in decreasing Ku70 levels in apoptotic cells. Ku70 forms a heterodimer with Ku80, which is required for the DNA repair activity of Ku proteins. We also found that Ku80 levels decreased in apoptotic cells and that Ku80 is a target of ubiquitin. Ubiquitinated Ku70 was not found in the Ku70-Ku80 heterodimer, suggesting that modification by ubiquitin inhibits Ku heterodimer formation. We propose that the ubiquitin-dependent modification of Ku70 plays an important role in the control of cellular levels of Ku70.
Collapse
Affiliation(s)
- Vivian Gama
- Case Comprehensive Cancer Center, Department of Pharmacology and Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | | | | | | | | | | | | |
Collapse
|
48
|
Keast JR. Plasticity of pelvic autonomic ganglia and urogenital innervation. INTERNATIONAL REVIEW OF CYTOLOGY 2006; 248:141-208. [PMID: 16487791 DOI: 10.1016/s0074-7696(06)48003-7] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Pelvic ganglia contain a mixture of sympathetic and parasympathetic neurons and provide most of the motor innervation of the urogenital organs. They show a remarkable sensitivity to androgens and estrogens, which impacts on their development into sexually dimorphic structures and provide an array of mechanisms by which plasticity of these neurons can occur during puberty and adulthood. The structure of pelvic ganglia varies widely among species, ranging from rodents, which have a pair of large ganglia, to humans, in whom pelvic ganglion neurons are distributed in a large, complex plexus. This plexus is frequently injured during pelvic surgical procedures, yet strategies for its repair have yet to be developed. Advances in this area will come from a better understanding of the effects of injury on the cellular signaling process in pelvic neurons and also the role of neurotrophic factors during development, maintenance, and repair of these axons.
Collapse
Affiliation(s)
- Janet R Keast
- Pain Management Research Institute, University of Sydney at Royal North Shore Hospital, St Leonards, New South Wales, Australia
| |
Collapse
|
49
|
Wang Q, Maniati M, Jabado O, Pavlaki M, Troy CM, Greene LA, Stefanis L. RAIDD is required for apoptosis of PC12 cells and sympathetic neurons induced by trophic factor withdrawal. Cell Death Differ 2005; 13:75-83. [PMID: 15947787 DOI: 10.1038/sj.cdd.4401690] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Caspase 2 has been implicated in trophic deprivation-induced neuronal death. We have shown that overexpression of the caspase 2-binding protein RAIDD induces neuronal apoptosis, acting synergistically with trophic deprivation. Currently, we examine the role of endogenous RAIDD in apoptosis of PC12 cells and sympathetic neurons. Expression of a truncated caspase recruitment domain-only form of caspase 2, which presumably disrupts the RAIDD interaction with endogenous caspase 2, attenuated trophic deprivation-induced apoptosis. Furthermore, downregulation of RAIDD by small interfering RNA led to inhibition of trophic deprivation-induced death, whereas death induced by DNA damage, which is not caspase 2-mediated, was not inhibited. Therefore, RAIDD, likely through interaction with caspase 2, is involved in trophic deprivation-induced neuronal apoptosis. This is the first demonstration of the involvement of RAIDD in apoptosis, and provides further support for the idea that apoptotic pathways in the same system may differ depending on the initiating stimulus.
Collapse
Affiliation(s)
- Q Wang
- Department of Neurology, Columbia University, New York, USA
| | | | | | | | | | | | | |
Collapse
|
50
|
Lindholm D, Arumäe U. Cell differentiation: reciprocal regulation of Apaf-1 and the inhibitor of apoptosis proteins. ACTA ACUST UNITED AC 2004; 167:193-5. [PMID: 15504905 PMCID: PMC2172544 DOI: 10.1083/jcb.200409171] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The molecular mechanisms by which differentiated cells combat cell death and injury have remained unclear. In the current issue, it has been shown in neurons that cell differentiation is accompanied by a decrease in Apaf-1 and the activity of the apoptosome with an increased ability of the inhibitor of apoptosis proteins (IAPs) to sustain survival (Wright et al., 2004). These results, together with earlier ones, deepen our understanding of how cell death and the apoptosome are regulated during differentiation and in tumor cells.
Collapse
Affiliation(s)
- Dan Lindholm
- Department of Neuroscience, Uppsala University, Biomedical Centre, S-751 23 Uppsala, Sweden.
| | | |
Collapse
|