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Niu ZX, Wang YT, Sun JF, Nie P, Herdewijn P. Recent advance of clinically approved small-molecule drugs for the treatment of myeloid leukemia. Eur J Med Chem 2023; 261:115827. [PMID: 37757658 DOI: 10.1016/j.ejmech.2023.115827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/14/2023] [Accepted: 09/20/2023] [Indexed: 09/29/2023]
Abstract
Myeloid leukemia denotes a hematologic malignancy characterized by aberrant proliferation and impaired differentiation of blood progenitor cells within the bone marrow. Despite the availability of several treatment options, the clinical outlook for individuals afflicted with myeloid leukemia continues to be unfavorable, making it a challenging disease to manage. Over the past, substantial endeavors have been dedicated to the identification of novel targets and the advancement of enhanced therapeutic modalities to ameliorate the management of this disease, resulting in the discovery of many clinically approved small-molecule drugs for myeloid leukemia, including histone deacetylase inhibitors, hypomethylating agents, and tyrosine kinase inhibitors. This comprehensive review succinctly presents an up-to-date assessment of the application and synthetic routes of clinically sanctioned small-molecule drugs employed in the treatment of myeloid leukemia. Additionally, it provides a concise exploration of the pertinent challenges and prospects encompassing drug resistance and toxicity. Overall, this review effectively underscores the considerable promise exhibited by clinically endorsed small-molecule drugs in the therapeutic realm of myeloid leukemia, while concurrently shedding light on the prospective avenues that may shape the future landscape of drug development within this domain.
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Affiliation(s)
- Zhen-Xi Niu
- Department of Pharmacy, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, 450018, China
| | - Ya-Tao Wang
- First People's Hospital of Shangqiu, Henan Province, Shangqiu, 476100, China; Department of Orthopedics, China-Japan Union Hospital, Jilin University, Changchun, 130033, China.
| | - Jin-Feng Sun
- Key Laboratory of Natural Medicines of the Changbai Mountain, Ministry of Education, Yanbian University, College of Pharmacy, Yanji, Jilin, 133002, China.
| | - Peng Nie
- Rega Institute for Medical Research, Medicinal Chemistry, KU Leuven, Herestraat 49-Box 1041, 3000, Leuven, Belgium.
| | - Piet Herdewijn
- Rega Institute for Medical Research, Medicinal Chemistry, KU Leuven, Herestraat 49-Box 1041, 3000, Leuven, Belgium.
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2
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Wang D, Wu W, Callen E, Pavani R, Zolnerowich N, Kodali S, Zong D, Wong N, Noriega S, Nathan WJ, Matos-Rodrigues G, Chari R, Kruhlak MJ, Livak F, Ward M, Caldecott K, Di Stefano B, Nussenzweig A. Active DNA demethylation promotes cell fate specification and the DNA damage response. Science 2022; 378:983-989. [PMID: 36454826 PMCID: PMC10196940 DOI: 10.1126/science.add9838] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Neurons harbor high levels of single-strand DNA breaks (SSBs) that are targeted to neuronal enhancers, but the source of this endogenous damage remains unclear. Using two systems of postmitotic lineage specification-induced pluripotent stem cell-derived neurons and transdifferentiated macrophages-we show that thymidine DNA glycosylase (TDG)-driven excision of methylcytosines oxidized with ten-eleven translocation enzymes (TET) is a source of SSBs. Although macrophage differentiation favors short-patch base excision repair to fill in single-nucleotide gaps, neurons also frequently use the long-patch subpathway. Disrupting this gap-filling process using anti-neoplastic cytosine analogs triggers a DNA damage response and neuronal cell death, which is dependent on TDG. Thus, TET-mediated active DNA demethylation promotes endogenous DNA damage, a process that normally safeguards cell identity but can also provoke neurotoxicity after anticancer treatments.
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Affiliation(s)
- Dongpeng Wang
- Laboratory of Genome Integrity, National Cancer Institute NIH, Bethesda, MD, USA
| | - Wei Wu
- Laboratory of Genome Integrity, National Cancer Institute NIH, Bethesda, MD, USA
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Elsa Callen
- Laboratory of Genome Integrity, National Cancer Institute NIH, Bethesda, MD, USA
| | - Raphael Pavani
- Laboratory of Genome Integrity, National Cancer Institute NIH, Bethesda, MD, USA
| | - Nicholas Zolnerowich
- Laboratory of Genome Integrity, National Cancer Institute NIH, Bethesda, MD, USA
| | - Srikanth Kodali
- Stem Cells and Regenerative Medicine, Center for Cell and Gene Therapy, Department of Molecular and Cellular Biology and Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
- Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Dali Zong
- Laboratory of Genome Integrity, National Cancer Institute NIH, Bethesda, MD, USA
| | - Nancy Wong
- Laboratory of Genome Integrity, National Cancer Institute NIH, Bethesda, MD, USA
| | - Santiago Noriega
- Laboratory of Genome Integrity, National Cancer Institute NIH, Bethesda, MD, USA
| | - William J. Nathan
- Laboratory of Genome Integrity, National Cancer Institute NIH, Bethesda, MD, USA
| | | | - Raj Chari
- Genome Modification Core, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Michael J. Kruhlak
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Ferenc Livak
- Laboratory of Genome Integrity, National Cancer Institute NIH, Bethesda, MD, USA
| | - Michael Ward
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Keith Caldecott
- Genome Damage and Stability Centre, University of Sussex, Falmer Brighton, UK
| | - Bruno Di Stefano
- Stem Cells and Regenerative Medicine, Center for Cell and Gene Therapy, Department of Molecular and Cellular Biology and Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
- Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - André Nussenzweig
- Laboratory of Genome Integrity, National Cancer Institute NIH, Bethesda, MD, USA
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Chan ES, Ge Y, So YW, Bai YF, Liu L, Wang YT. Allosteric potentiation of GABAA receptor single-channel conductance by netrin-1 during neuronal-excitation-induced inhibitory synaptic homeostasis. Cell Rep 2022; 41:111584. [DOI: 10.1016/j.celrep.2022.111584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 07/13/2022] [Accepted: 10/08/2022] [Indexed: 11/06/2022] Open
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p53 is required for nuclear but not mitochondrial DNA damage-induced degeneration. Cell Death Dis 2021; 12:104. [PMID: 33473103 PMCID: PMC7817838 DOI: 10.1038/s41419-020-03373-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 12/16/2020] [Accepted: 12/22/2020] [Indexed: 12/18/2022]
Abstract
While the consequences of nuclear DNA damage have been well studied, the exact consequences of acute and selective mitochondrial DNA (mtDNA) damage are less understood. DNA damaging chemotherapeutic drugs are known to activate p53-dependent apoptosis in response to sustained nuclear DNA damage. While it is recognized that whole-cell exposure to these drugs also damages mtDNA, the specific contribution of mtDNA damage to cellular degeneration is less clear. To examine this, we induced selective mtDNA damage in neuronal axons using microfluidic chambers that allow for the spatial and fluidic isolation of neuronal cell bodies (containing nucleus and mitochondria) from the axons (containing mitochondria). Exposure of the DNA damaging drug cisplatin selectively to only the axons induced mtDNA damage in axonal mitochondria, without nuclear damage. We found that this resulted in the selective degeneration of only the targeted axons that were exposed to DNA damage, where ROS was induced but mitochondria were not permeabilized. mtDNA damage-induced axon degeneration was not mediated by any of the three known axon degeneration pathways: apoptosis, axon pruning, and Wallerian degeneration, as Bax-deficiency, or Casp3-deficiency, or Sarm1-deficiency failed to protect the degenerating axons. Strikingly, p53, which is essential for degeneration after nuclear DNA damage, was also not required for degeneration induced with mtDNA damage. This was most evident when the p53-deficient neurons were globally exposed to cisplatin. While the cell bodies of p53-deficient neurons were protected from degeneration in this context, the axons farthest from the cell bodies still underwent degeneration. These results highlight how whole cell exposure to DNA damage activates two pathways of degeneration; a faster, p53-dependent apoptotic degeneration that is triggered in the cell bodies with nuclear DNA damage, and a slower, p53-independent degeneration that is induced with mtDNA damage.
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Nakayama S, Adachi M, Hatano M, Inahata N, Nagao T, Fukushima N. Cytosine arabinoside induces phosphorylation of histone H2AX in hippocampal neurons via a noncanonical pathway. Neurochem Int 2020; 142:104933. [PMID: 33290798 DOI: 10.1016/j.neuint.2020.104933] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 12/01/2020] [Accepted: 12/02/2020] [Indexed: 11/29/2022]
Abstract
Cytosine arabinoside (Ara-C), an anticancer drug, is known to inhibit DNA replication in mitotic cells. Ara-C is also considered to induce DNA damage, leading to neuronal cell death. To identify the mechanism by which Ara-C kills neurons, we assessed the levels of phosphorylated histone H2AX (γ-H2AX), a marker for DNA double-strand breaks (DSBs), in hippocampal neurons cultured for 48 h with Ara-C. There was a time-dependent increase in the percentage of cells accumulating γ-H2AX, but TUNEL staining did not indicate the formation of DSBs. The nuclear spread of γ-H2AX remained after Ara-C was withdrawn. These features of Ara-C-induced γ-H2AX formation were quite distinct from those observed in proliferating pheochromocytoma cells. Furthermore, Ara-C-induced γ-H2AX formation appeared to utilize cyclin-dependent kinase 7, but not ataxia telangiectasia mutated (ATM) or ATM and Rad3 related, which are well-known kinases in γ-H2AX formation. Taken together, our findings indicated that Ara-C stimulated γ-H2AX formation in neurons without DSB formation and utilization of canonical kinases, leading to neuronal cell death.
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Affiliation(s)
- Saki Nakayama
- Department of Life Science, Kindai University, Higashiosaka, Japan
| | - Miyu Adachi
- Department of Life Science, Kindai University, Higashiosaka, Japan
| | - Misaki Hatano
- Department of Life Science, Kindai University, Higashiosaka, Japan
| | - Noriyuki Inahata
- Department of Life Science, Kindai University, Higashiosaka, Japan
| | - Tetsuji Nagao
- Department of Life Science, Kindai University, Higashiosaka, Japan
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Interneuron dysfunction in epilepsy: An experimental approach using immature brain insults to induce neuronal migration disorders. Epilepsy Res 2019; 156:106185. [DOI: 10.1016/j.eplepsyres.2019.106185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 07/13/2019] [Accepted: 08/02/2019] [Indexed: 01/16/2023]
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Bcl-xL Is Essential for the Survival and Function of Differentiated Neurons in the Cortex That Control Complex Behaviors. J Neurosci 2017; 36:5448-61. [PMID: 27194326 DOI: 10.1523/jneurosci.4247-15.2016] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 03/29/2016] [Indexed: 12/21/2022] Open
Abstract
UNLABELLED Apoptosis plays an essential role during brain development, yet the precise mechanism by which this pathway is regulated in the brain remains unknown. In particular, mammalian cells are known to express multiple anti-apoptotic Bcl-2 family proteins. However, the cells of the developing brain could also exist in a primed state in which the loss of a single anti-apoptotic Bcl-2 family protein is sufficient to trigger apoptosis. Here, we examined the critical role of Bcl-xL, an anti-apoptotic protein, during brain development. Using conditional knock-out mice in which Bcl-xL is deleted in neural progenitor cells (Bcl-xL(Emx1-Cre)), we show that the loss of Bcl-xL is not sufficient to trigger apoptosis in these proliferating progenitors. In contrast, specific populations of postmitotic neurons derived from these progenitors, including upper layer cortical neurons and the CA1-CA3 regions of the hippocampus, were acutely dependent on Bcl-xL. Consistent with this finding, deletion of Bcl-xL selectively in the postmitotic neurons in the brain (Bcl-xL(Nex-Cre)) also resulted in similar patterns of apoptosis. This Bcl-xL deficiency-induced neuronal death was a consequence of activation of the apoptotic pathway, because the cell death was rescued with codeletion of the proapoptotic proteins Bax and Bak. Importantly, the loss of these Bcl-xL-dependent neurons led to severe neurobehavioral abnormalities, including deficits in motor learning, hyperactivity, and increased risk-taking and self-injurious behaviors. Together, our results identify a population of neurons in the developing brain that are acutely dependent on Bcl-xL during the peak period of synaptic connectivity that are important for the establishment of higher-order complex behaviors. SIGNIFICANCE STATEMENT Although Bcl-xL is known to inhibit apoptosis, exactly which cells in the brain are dependent on Bcl-xL has remained unclear because of the embryonic lethality of mice globally deleted for Bcl-xL. Here, we conditionally deleted Bcl-xL in the brain and found that this did not result in widespread apoptosis in the proliferating progenitors. Instead, Bcl-xL deficiency induced apoptosis in a select population of differentiated neurons predominantly in the early postnatal stages. Importantly, these Bcl-xL-dependent neurons are not essential for survival of the organism but instead regulate complex behaviors. Our results show that the selective loss of these Bcl-xL-dependent neurons results in mice exhibiting severe neurobehavioral abnormalities, including self-injurious and risk-taking behaviors, hyperactivity, and learning and memory defects.
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8
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Electrical stimulation inhibits cytosine arabinoside-induced neuronal death by preventing apoptosis in dorsal root ganglion neurons. Neuroreport 2016; 27:1217-24. [PMID: 27603731 DOI: 10.1097/wnr.0000000000000681] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The current study aimed to investigate whether electrical stimulation could prevent apoptotic neuronal cell death during treatment with cytosine arabinoside (ara-C). From in-vitro experiments, the effects of electrical stimulation were assessed on neurite fragmentation and neuronal cell death in ara-C-treated dorsal root ganglion (DRG) explants. Ara-C treatment increased neurite fragmentation and neuronal cell death in DRG explants and activated caspase-3 by cleaving it, which could induce apoptosis. Electrical stimulation can significantly reduce neurite fragmentation and neuronal cell death compared with nonelectrically stimulated groups. Furthermore, electrical stimulation inhibited caspase-3 activation and reduced apoptotic neuronal death in DRG explants. It was suggested that the neuroprotective effect of electrical stimulation is likely mediated by the inhibition of caspase-3 activation and therefore the inhibition of apoptosis following ara-C treatment.
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Borland KM, AbdulSalam SF, Solivio MJ, Burke MP, Wolfkiel PR, Lawson SM, Stockman CA, Andersen JM, Smith S, Tolstolutskaya JN, Gurjar PN, Bercz AP, Merino EJ, Litosh VA. Base-modified thymidines capable of terminating DNA synthesis are novel bioactive compounds with activity in cancer cells. Bioorg Med Chem 2015; 23:1869-81. [PMID: 25778768 DOI: 10.1016/j.bmc.2015.01.057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 01/22/2015] [Accepted: 01/30/2015] [Indexed: 10/24/2022]
Abstract
Current FDA-approved chemotherapeutic antimetabolites elicit severe side effects that warrant their improvement; therefore, we designed compounds with mechanisms of action focusing on inhibiting DNA replication rather than targeting multiple pathways. We previously discovered that 5-(α-substituted-2-nitrobenzyloxy)methyluridine-5'-triphosphates were exquisite DNA synthesis terminators; therefore, we synthesized a library of 35 thymidine analogs and evaluated their activity using an MTT cell viability assay of MCF7 breast cancer cells chosen for their vulnerability to these nucleoside derivatives. Compound 3a, having an α-tert-butyl-2-nitro-4-(phenyl)alkynylbenzyloxy group, showed an IC50 of 9±1μM. The compound is more selective for cancer cells than for fibroblast cells compared with 5-fluorouracil. Treatment of MCF7 cells with 3a elicits the DNA damage response as indicated by phosphorylation of γ-H2A. A primer extension assay of the 5'-triphosphate of 3a revealed that 3aTP is more likely to inhibit DNA polymerase than to lead to termination events upon incorporation into the DNA replication fork.
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Affiliation(s)
- Kayla M Borland
- Department of Chemistry, University of Cincinnati, 301 Clifton Ct. ML 0172, Cincinnati, OH 45221-0172, USA
| | - Safnas F AbdulSalam
- Department of Chemistry, University of Cincinnati, 301 Clifton Ct. ML 0172, Cincinnati, OH 45221-0172, USA
| | - Morwena J Solivio
- Department of Chemistry, University of Cincinnati, 301 Clifton Ct. ML 0172, Cincinnati, OH 45221-0172, USA
| | - Matthew P Burke
- Department of Chemistry, University of Cincinnati, 301 Clifton Ct. ML 0172, Cincinnati, OH 45221-0172, USA
| | - Patrick R Wolfkiel
- Department of Chemistry, University of Cincinnati, 301 Clifton Ct. ML 0172, Cincinnati, OH 45221-0172, USA
| | - Sean M Lawson
- Department of Chemistry, University of Cincinnati, 301 Clifton Ct. ML 0172, Cincinnati, OH 45221-0172, USA
| | - Courtney A Stockman
- Department of Chemistry, University of Cincinnati, 301 Clifton Ct. ML 0172, Cincinnati, OH 45221-0172, USA
| | - Joel M Andersen
- Department of Chemistry, University of Cincinnati, 301 Clifton Ct. ML 0172, Cincinnati, OH 45221-0172, USA
| | - Skyler Smith
- Department of Chemistry, University of Cincinnati, 301 Clifton Ct. ML 0172, Cincinnati, OH 45221-0172, USA
| | - Julia N Tolstolutskaya
- Department of Chemistry, University of Cincinnati, 301 Clifton Ct. ML 0172, Cincinnati, OH 45221-0172, USA
| | - Purujit N Gurjar
- Department of Chemistry, University of Cincinnati, 301 Clifton Ct. ML 0172, Cincinnati, OH 45221-0172, USA
| | - Aron P Bercz
- Department of Chemistry, University of Cincinnati, 301 Clifton Ct. ML 0172, Cincinnati, OH 45221-0172, USA
| | - Edward J Merino
- Department of Chemistry, University of Cincinnati, 301 Clifton Ct. ML 0172, Cincinnati, OH 45221-0172, USA
| | - Vladislav A Litosh
- Department of Chemistry, University of Cincinnati, 301 Clifton Ct. ML 0172, Cincinnati, OH 45221-0172, USA.
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Coffin AB, Rubel EW, Raible DW. Bax, Bcl2, and p53 differentially regulate neomycin- and gentamicin-induced hair cell death in the zebrafish lateral line. J Assoc Res Otolaryngol 2013; 14:645-59. [PMID: 23821348 DOI: 10.1007/s10162-013-0404-1] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 06/20/2013] [Indexed: 12/19/2022] Open
Abstract
Sensorineural hearing loss is a normal consequence of aging and results from a variety of extrinsic challenges such as excessive noise exposure and certain therapeutic drugs, including the aminoglycoside antibiotics. The proximal cause of hearing loss is often death of inner ear hair cells. The signaling pathways necessary for hair cell death are not fully understood and may be specific for each type of insult. In the lateral line, the closely related aminoglycoside antibiotics neomycin and gentamicin appear to kill hair cells by activating a partially overlapping suite of cell death pathways. The lateral line is a system of hair cell-containing sense organs found on the head and body of aquatic vertebrates. In the present study, we use a combination of pharmacologic and genetic manipulations to assess the contributions of p53, Bax, and Bcl2 in the death of zebrafish lateral line hair cells. Bax inhibition significantly protects hair cells from neomycin but not from gentamicin toxicity. Conversely, transgenic overexpression of Bcl2 attenuates hair cell death due to gentamicin but not neomycin, suggesting a complex interplay of pro-death and pro-survival proteins in drug-treated hair cells. p53 inhibition protects hair cells from damage due to either aminoglycoside, with more robust protection seen against gentamicin. Further experiments evaluating p53 suggest that inhibition of mitochondrial-specific p53 activity confers significant hair cell protection from either aminoglycoside. These results suggest a role for mitochondrial p53 activity in promoting hair cell death due to aminoglycosides, likely upstream of Bax and Bcl2.
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Affiliation(s)
- Allison B Coffin
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Box 357923, Seattle, WA, 98195, USA,
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11
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Interleukin-17A increases neurite outgrowth from adult postganglionic sympathetic neurons. J Neurosci 2012; 32:1146-55. [PMID: 22279201 DOI: 10.1523/jneurosci.5343-11.2012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Inflammation can profoundly alter the structure and function of the nervous system. Interleukin (IL)-17 has been implicated in the pathogenesis of several inflammatory diseases associated with nervous system plasticity. However, the effects of IL-17 on the nervous system remain unexplored. Cell and explant culture techniques, immunohistochemistry, electrophysiology, and Ca2+ imaging were used to examine the impact of IL-17 on adult mouse sympathetic neurons. Receptors for IL-17 were present on postganglionic neurons from superior mesenteric ganglia (SMG). Supernatant from activated splenic T lymphocytes, which was abundant in IL-17, dramatically enhanced axonal length of SMG neurons. Importantly, IL-17-neutralizing antiserum abrogated the neurotrophic effect of splenocyte supernatant, and incubation of SMG neurons in IL-17 (1 ng/ml) significantly potentiated neurite outgrowth. The neurotrophic effect of IL-17 was accompanied by inhibition of voltage-dependent Ca2+ influx and was recapitulated by incubation of neurons in a blocker of N-type Ca2+ channels (ω-conotoxin GVIA; 30 nM). IL-17-induced neurite outgrowth in vitro appeared to be independent of glia, as treatment with a glial toxin (AraC; 5 μM) did not affect the outgrowth response to IL-17. Moreover, application of the cytokine to distal axons devoid of glial processes enhanced neurite extension. An inhibitor of the NF-κB pathway (SC-514; 20 μM) blocked the effects of IL-17. These data represent the first evidence that IL-17 can act on sympathetic somata and distal neurites to enhance neurite outgrowth, and identify a novel potential role for IL-17 in the neuroanatomical plasticity that accompanies inflammation.
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Patel RS, Rachamalla M, Chary NR, Shera FY, Tikoo K, Jena G. Cytarabine induced cerebellar neuronal damage in juvenile rat: Correlating neurobehavioral performance with cellular and genetic alterations. Toxicology 2012; 293:41-52. [DOI: 10.1016/j.tox.2011.12.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 12/08/2011] [Accepted: 12/10/2011] [Indexed: 11/25/2022]
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13
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Bernstein AI, Garrison SP, Zambetti GP, O'Malley KL. 6-OHDA generated ROS induces DNA damage and p53- and PUMA-dependent cell death. Mol Neurodegener 2011; 6:2. [PMID: 21211034 PMCID: PMC3025875 DOI: 10.1186/1750-1326-6-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 01/06/2011] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Parkinson's disease (PD) is characterized by the selective loss of dopaminergic neurons in the substantia nigra (SN), resulting in tremor, rigidity, and bradykinesia. Although the etiology is unknown, insight into the disease process comes from the dopamine (DA) derivative, 6-hydroxydopamine (6-OHDA), which produces PD-like symptoms. Studies show that 6-OHDA activates stress pathways, such as the unfolded protein response (UPR), triggers mitochondrial release of cytochrome-c, and activates caspases, such as caspase-3. Because the BH3-only protein, Puma (p53-upregulated mediator of apoptosis), is activated in response to UPR, it is thought to be a link between cell stress and apoptosis. RESULTS To test the hypothesis that Puma serves such a role in 6-OHDA-mediated cell death, we compared the response of dopaminergic neurons from wild-type and Puma-null mice to 6-OHDA. Results indicate that Puma is required for 6-OHDA-induced cell death, in primary dissociated midbrain cultures as well as in vivo. In these cultures, 6-OHDA-induced DNA damage and p53 were required for 6-OHDA-induced cell death. In contrast, while 6-OHDA led to upregulation of UPR markers, loss of ATF3 did not protect against 6-OHDA. CONCLUSIONS Together, our results indicate that 6-OHDA-induced upregulation of Puma and cell death are independent of UPR. Instead, p53 and DNA damage repair pathways mediate 6-OHDA-induced toxicity.
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Affiliation(s)
- Alison I Bernstein
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St, Louis, MO 63110, USA.
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Lee SB, Kwon IS, Park J, Lee KH, Ahn Y, Lee C, Kim J, Choi SY, Cho SW, Ahn JY. Ribosomal protein S3, a new substrate of Akt, serves as a signal mediator between neuronal apoptosis and DNA repair. J Biol Chem 2010; 285:29457-68. [PMID: 20605787 DOI: 10.1074/jbc.m110.131367] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
RPS3, a conserved, eukaryotic ribosomal protein of the 40 S subunit, is required for ribosome biogenesis. Because ribosomal proteins are abundant and ubiquitous, they may have additional extraribosomal functions. Here, we show that human RPS3 is a physiological target of Akt kinase and a novel mediator of neuronal apoptosis. NGF stimulation resulted in phosphorylation of threonine 70 of RPS3 by Akt, and this phosphorylation was required for Akt binding to RPS3. RPS3 induced neuronal apoptosis, up-regulating proapoptotic proteins Dp5/Hrk and Bim by binding to E2F1 and acting synergistically with it. Akt-dependent phosphorylation of RPS3 inhibited its proapoptotic function and perturbed its interaction with E2F1. These events coincided with nuclear translocation and accumulation of RPS3, where it functions as an endonuclease. Nuclear accumulation of RPS3 results in an increase in DNA repair activity to some extent, thereby sustaining neuronal survival. Abolishment of Akt-mediated RPS3 phosphorylation through mutagenesis accelerated apoptotic cell death and severely compromised nuclear translocation of RPS3. Thus, our findings define an extraribosomal role of RPS3 as a molecular switch that accommodates apoptotic induction to DNA repair through Akt-mediated phosphorylation.
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Affiliation(s)
- Sang Bae Lee
- Department of Molecular Cell Biology, Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Korea
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15
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Richter MW, Roskams AJ. Corticospinal neurons respond differentially to neurotrophins and myelin-associated glycoprotein in vitro. J Neurosci Res 2009; 87:2222-36. [PMID: 19301432 DOI: 10.1002/jnr.22053] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Elucidating the mechanisms that regulate the survival and outgrowth of corticospinal tract (CST) neurons and other CNS tracts will be a key component in developing novel approaches for the treatment of central nervous system (CNS) disorders, including stroke, spinal cord injury (SCI), and motor neuron disease (MND). However, the in vivo complexities of these diseases make a systematic evaluation of potential therapeutics that directly affect corticospinal regeneration or survival very challenging. Here, we use Thy1.2 transgenic mice expressing yellow fluorescent protein (YFP) in postnatal day 8 (P8) corticospinal neurons, as a source of CST neurons that have already established synapses in the spinal cord, to assess factors that influence neurite outgrowth and survival of axotomized CST neurons. After culture, YFP-positive corticospinal neurons represent an enriched neuronal population over other glia and interneurons, survive, and extend processes over time. YFP-positive CST neurons also continue to express the corticospinal markers CTIP2 and Otx1. CST neurons display different degrees of axon extension, dendritic branch length and elaboration, and neurite elongation in response to neurotrophin-3 and ciliary neurotrophic factor, and an inhibitory outgrowth response when cultured on myelin-associated glycoprotein. Some CST neurons are lost with extended culture, which provides a baseline from which we can also assess factors that enhance CST neuron survival. This assay thus allows us to assess independent aspects of CST axonal and dendritic outgrowth kinetics, which allows for the rapid and sensitive investigation of new therapies to address corticospinal neuron outgrowth in the context of CNS injury and neurodegenerative disorders.
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Affiliation(s)
- Miranda W Richter
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
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16
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Horvát-Karajz K, Balogh Z, Kovács V, drRerNat AH, Sréter L, Uher F. In vitro effect of carboplatin, cytarabine, paclitaxel, vincristine, and low-power laser irradiation on murine mesenchymal stem cells. Lasers Surg Med 2009; 41:463-9. [DOI: 10.1002/lsm.20791] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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17
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Motagally MA, Lukewich MK, Chisholm SP, Neshat S, Lomax AE. Tumour necrosis factor alpha activates nuclear factor kappaB signalling to reduce N-type voltage-gated Ca2+ current in postganglionic sympathetic neurons. J Physiol 2009; 587:2623-34. [PMID: 19403618 DOI: 10.1113/jphysiol.2009.172312] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Inflammation has profound effects on the innervation of affected tissues, including altered neuronal excitability and neurotransmitter release. As Ca(2+) influx through voltage-gated Ca(2+) channels (VGCCs) is a critical determinant of excitation-secretion coupling in nerve terminals, the aim of this study was to characterize the effect of overnight incubation in the inflammatory mediator tumour necrosis factor alpha (TNFalpha; 1 nM) on VGCCs in dissociated neurons from mouse superior mesenteric ganglia (SMG). Voltage-gated Ca(2+) currents (I(Ca)) were measured using the perforated patch clamp technique and the VGCC subtypes present in SMG neurons were estimated based on inhibition by selective VGCC blockers: omega-conotoxin GVIA (300 nM; N-type), nifedipine (10 microM; L-type), and omega-conotoxin MVIIC (300 nM; N-, P/Q-type). We used intracellular Ca(2+) imaging with Fura-2 AM to compare Ca(2+) influx during depolarizations in control and TNFalpha-treated neurons. TNF receptor and VGCC mRNA expression were measured using PCR, and channel alpha subunit (CaV2.2) was localized with immunohistochemistry. Incubation in TNFalpha significantly decreased I(Ca) amplitude and depolarization-induced Ca(2+) influx. The reduction in I(Ca) was limited to omega-conotoxin GVIA-sensitive N-type Ca(2+) channels. Depletion of glial cells by incubation in cytosine arabinoside (5 microM) did not affect I(Ca) inhibition by TNFalpha. Preincubation of neurons with SC-514 (20 microM) or BAY 11-7082 (1 microM), which both inhibit nuclear factor kappaB signalling, prevented the reduction in I(Ca) by TNFalpha. Inhibition of N-type VGCCs following TNFalpha incubation was associated with a decrease in CaV2.2 mRNA and reduced membrane localization of CaV2.2 immunoreactivity. These data suggest that TNFalpha inhibits I(Ca) in SMG neurons and identify a novel role for NF-kappaB in the regulation of neurotransmitter release during inflammatory conditions with elevated circulating TNFalpha, such as Crohn's disease and Guillain-Barré syndrome.
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18
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Li CQ, Liu D, Huang L, Wang H, Zhang JY, Luo XG. Cytosine arabinoside treatment impairs the remote spatial memory function and induces dendritic retraction in the anterior cingulate cortex of rats. Brain Res Bull 2008; 77:237-40. [DOI: 10.1016/j.brainresbull.2008.07.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2008] [Revised: 07/22/2008] [Accepted: 07/28/2008] [Indexed: 01/28/2023]
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19
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Wright KM, Smith MI, Farrag L, Deshmukh M. Chromatin modification of Apaf-1 restricts the apoptotic pathway in mature neurons. ACTA ACUST UNITED AC 2007; 179:825-32. [PMID: 18056406 PMCID: PMC2099178 DOI: 10.1083/jcb.200708086] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Although apoptosis has been extensively studied in developing neurons, the dynamic changes in this pathway after neuronal maturation remain largely unexplored. We show that as neurons mature, cytochrome c– mediated apoptosis progresses from inhibitor of apoptosis protein–dependent to –independent regulation because of a complete loss of Apaf-1 expression. However, after DNA damage, mature neurons resynthesize Apaf-1 through the cell cycle–related E2F1 pathway and restore their apoptotic potential. Surprisingly, we find that E2F1 is sufficient to induce Apaf-1 expression in developing but not mature neurons. Rather, Apaf-1 up-regulation in mature neurons requires both chromatin derepression and E2F1 transcriptional activity. This differential capacity of E2F1 to induce Apaf-1 transcription is because of the association of the Apaf-1 promoter with active chromatin in developing neurons and repressed chromatin in mature neurons. These data specifically illustrate how the apoptotic pathway in mature neurons becomes increasingly restricted by a novel mechanism involving the regulation of chromatin structure.
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Affiliation(s)
- Kevin M Wright
- Neuroscience Center and 2Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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20
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Kanno SI, Hiura T, Shouji A, Osanai Y, Ujibe M, Ishikawa M. Resistance to Ara-C up-regulates the activation of NF-kappaB, telomerase activity and Fas expression in NALM-6 cells. Biol Pharm Bull 2007; 30:2069-74. [PMID: 17978477 DOI: 10.1248/bpb.30.2069] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cytosine arabinoside (1-beta-D-arabinofuranosylcytosine; Ara-C) is the most important antimetabolite used to induce remission in acute leukemia, but cellular resistance to Ara-C reflects a poor prognosis in cancer chemotherapy. To further investigate the mechanisms of resistance to Ara-C, we have established Ara-C-resistant NALM-6 cells. The activation of nuclear factor kappaB (NF-kappaB) was accompanied by the acquisition of Ara-C resistance. Telomerase activity has also increased with the acquisition of Ara-C resistance. The expression of Bid, Bax, or p53 proteins have been shown to increase correlated with the acquisition of Ara-C resistance. In contrast to the increase in these proteins, Bcl-2, Bcl-x, and Bag-1 proteins remained unchanged with the acquisition of Ara-C resistance. Fas expression increased with the acquisition of Ara-C resistance in the late stage. The induction of apoptosis and reduction of cell viability by cytotoxic anti-Fas antibody was more susceptible in resistant cells than parental cells. In conclusion, this report has shown that resistance to Ara-C up-regulates the activation of NF-kappaB, telomerase activity and Fas expression.
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Affiliation(s)
- Syu-ichi Kanno
- Department of Clinical Pharmacotherapeutics, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, Japan.
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21
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Smith MI, Deshmukh M. Endoplasmic reticulum stress-induced apoptosis requires bax for commitment and Apaf-1 for execution in primary neurons. Cell Death Differ 2007; 14:1011-9. [PMID: 17218955 DOI: 10.1038/sj.cdd.4402089] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Apoptosis triggered by endoplasmic reticulum (ER) stress is associated with various pathophysiological conditions including neurodegenerative diseases and ischemia. However, the mechanism by which ER stress induces neuronal apoptosis remains controversial. Here we identify the pathway of apoptosis carried out in sympathetic neurons triggered to die by ER stress-inducing agent tunicamycin. We find that ER stress induces a neuronal apoptotic pathway which upregulates BH3-only genes DP5 and Puma. Importantly, we show that ER stress commits neurons to die before cytochrome c release and this commitment requires Bax activation and c-jun N-terminal kinase signaling. Furthermore, ER stress engages the mitochondrial pathway of death as neurons release cytochrome c and Apaf-1 deficiency is sufficient to block apoptosis. Our findings identify a critical function of Bax in committing neurons to ER stress-induced apoptosis and clarify the importance of the apoptosome as the non-redundant caspase activation pathway to execute neuronal apoptosis in response to ER stress.
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Affiliation(s)
- M I Smith
- Department of Cell and Developmental Biology and Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA
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22
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Vaughn AE, Deshmukh M. Essential postmitochondrial function of p53 uncovered in DNA damage-induced apoptosis in neurons. Cell Death Differ 2007; 14:973-81. [PMID: 17218959 DOI: 10.1038/sj.cdd.4402084] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
In postmitotic sympathetic neurons, unlike most mitotic cells, death by apoptosis requires not only the release of cytochrome c from the mitochondria, but also an additional step to relieve X-linked inhibitor of apoptosis protein (XIAP)'s inhibition of caspases. Here, we examined the mechanism by which XIAP is inactivated following DNA damage and found that it is achieved by a mechanism completely different from that following apoptosis by nerve growth factor (NGF) deprivation. NGF deprivation relieves XIAP by selectively degrading it, whereas DNA damage overcomes XIAP via a p53-mediated induction of Apaf-1. Unlike wild-type neurons, p53-deficient neurons fail to overcome XIAP and remain resistant to cytochrome c after DNA damage. Restoring Apaf-1 induction in p53-deficient neurons is sufficient to overcome XIAP and sensitize cells to cytochrome c. Although a role for p53 in apoptosis upstream of cytochrome c release has been well established, this study uncovers an additional, essential role for p53 in regulating caspase activation downstream of mitochondria following DNA damage in neurons.
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Affiliation(s)
- A E Vaughn
- Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, NC 27599, USA
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23
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Koros C, Papalexi E, Anastasopoulos D, Kittas C, Kitraki E. Effects of AraC treatment on motor coordination and cerebellar cytoarchitecture in the adult rat. Neurotoxicology 2007; 28:83-92. [PMID: 16973216 DOI: 10.1016/j.neuro.2006.07.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Revised: 07/19/2006] [Accepted: 07/27/2006] [Indexed: 11/30/2022]
Abstract
Intact cerebellum cytoarchitecture and cellular communication are indispensable for successful motor coordination and certain forms of memory. Cytosine arabinoside (AraC), often used as an anti-neoplastic agent in humans, can have cerebellum-targeting adverse effects. In order to characterize the nature of AraC-induced cerebellar lesions in an adult rodent model, we have administered AraC (400 mg/kg b.w., i.p.) in adult male Wistar rats for 5 days. The animals' walking pattern, motor coordination, locomotion, spatial navigation and cognition were evaluated, along with neurofilament- and calbindin-like distribution in the cerebellum. AraC-treated rats demonstrated a disturbed walking pattern and a reduced ability of motor learning and coordination, indicative of a mild cerebellar deficit. Although the general locomotion and spatial cognition of AraC-treated rats was not significantly altered, their navigation into the water, in terms of swimming velocity, was irregular, compared to vehicle-treated animals. Neurofilament-like immunostaining was reduced in the molecular cerebellar layer, while calbindin D 28 kDa levels were increased in Purkinje neurons, following AraC treatment. Administration of the antioxidant N-acetylcysteine (NAC) (200 mg/kg b.w., p.o.), for 14 days (prior to and during AraC treatment) largely prevented the AraC-induced behavioral deficits. Our in vivo model of neurotoxicity provides data on the AraC-induced behavioral and cellular alterations concerning the adult rat cerebellum. Furthermore, it provides evidence of a possible neuroprophylactic role of the antioxidant N-acetylcysteine in this model of chemotherapy-induced toxicity.
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Affiliation(s)
- Christos Koros
- Laboratory of Histology and Embryology, Athens University Medical School, Athens, Greece.
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24
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Besirli CG, Johnson EM. The activation loop phosphorylation of protein kinase D is an early marker of neuronal DNA damage. J Neurochem 2006; 99:218-25. [PMID: 16911582 DOI: 10.1111/j.1471-4159.2006.04116.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In neurons, DNA damage induces protein synthesis-dependent apoptosis mediated by the mitochondrial intrinsic cell-death pathway. Signal transduction cascades activated by genotoxic stress upstream of the mitochondria are largely unknown. We identified protein kinase D (PKD) as one of the earliest markers of neuronal DNA damage. Phosphorylation of the PKD-activation domain could be detected within 15 min of genotoxic stress and was concurrent with ataxia telangiectasia-mutated (ATM) activation. PKD stimulation was selective to DNA damage and did not occur with other stress stimuli examined. In vivo, both young and adult rats showed increased levels of phosphorylated PKD in neuronal tissues after injection of DNA-toxin etoposide. These results indicate that PKD activation is an early neuronal response to DNA damage, suggesting that signaling downstream of PKD may be critical for neuronal survival after genotoxic stress.
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Affiliation(s)
- Cagri G Besirli
- Department of Neurology, Washington University School of Medicine, Saint Louis, Missouri, USA
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25
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Phillips W, Michell AW, Barker RA. Neurogenesis in diseases of the central nervous system. Stem Cells Dev 2006; 15:359-79. [PMID: 16846374 DOI: 10.1089/scd.2006.15.359] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Neurogenesis is altered in ageing, and diseases of the central nervous system (CNS) such as neurodegenerative disorders. We discuss the process of neurogenesis, its relevance for disorders of the CNS, the dynamic nature of neurogenesis, how and why it may be abnormal in ageing, and disease, and possibilities to ameliorate abnormal neurogenesis in disease.
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26
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Takano T, Akahori S, Takeuchi Y, Ohno M. Neuronal apoptosis and gray matter heterotopia in microcephaly produced by cytosine arabinoside in mice. Brain Res 2006; 1089:55-66. [PMID: 16638609 DOI: 10.1016/j.brainres.2006.03.047] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2005] [Revised: 03/01/2006] [Accepted: 03/07/2006] [Indexed: 11/27/2022]
Abstract
Primary microcephaly can be accompanied by numerous migration anomalies. This experiment was undertaken to examine the pathogenesis of gray matter heterotopia and microcephaly that is produced after administering cytosine arabinoside (Ara-C) to mice. Pregnant mice were intraperitoneally injected with Ara-C at 30 mg/kg body weight on days 13.5 and 14.5 of gestation, and then their offspring were examined. On embryonic day 15.5, in the ventricular zone of the cingulate cortex, the neuroepithelial cells lacked BrdU immunoreactivity. Nestin-immunoreactive radial glial fibers and calretinin-positive subplate fibers were disrupted. TUNEL reaction was remarkable throughout the cerebral hemisphere. Subcortical heterotopia in the cingulate cortex and subependymal nodular heterotopia in the dorsolateral part of the lateral ventricles became detectable by the first day after birth. Thirty-two days after birth, microcephaly was apparent; subcortical heterotopia was observed to have increased in size while it was still located in the frontal and cingulate cortices. This experiment demonstrated that Ara-C induces neuronal apoptosis throughout the cerebral hemisphere. The immunohistochemical characteristics in the gray matter heterotopia suggest that both the subcortical and the subependymal heterotopias were formed by neurons originally committed to the neocortex. We conclude that the gray matter heterotopia that accompanies the microcephaly was produced by a disturbance of radial, tangential, and interkinetic neuronal migrations due to the toxicity of Ara-C in the immature developing brain.
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Affiliation(s)
- Tomoyuki Takano
- Department of Pediatrics, Shiga University of Medical Science, Seta-Tsukinowa, Otsu 520-2192, Japan.
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27
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Wyttenbach A, Tolkovsky AM. The BH3-only protein Puma is both necessary and sufficient for neuronal apoptosis induced by DNA damage in sympathetic neurons. J Neurochem 2006; 96:1213-26. [PMID: 16478523 DOI: 10.1111/j.1471-4159.2005.03676.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
DNA damage activates apoptosis in several neuronal populations and is an important component of neuropathological conditions. While it is well established that neuronal apoptosis, induced by DNA damage, is dependent on the key cell death regulators p53 and Bax, it is unknown which proteins link the p53 signal to Bax. Using rat sympathetic neurons as an in vitro model of neuronal apoptosis, we show that cytosine arabinoside is a DNA damaging drug that induces the expression of the BH3-only pro-apoptotic genes Noxa, Puma and Bim. Increased expression occurred after p53 activation, measured by its phosphorylation at serine 15, but prior to the conformational change of Bax at the mitochondria, cytochrome c (cyt c) release and apoptosis. Hence Noxa, Puma and Bim could potentially link p53 to Bax. We directly tested this hypothesis by the use of nullizygous mice. We show that Puma, but not Bim or Noxa, is a crucial mediator of DNA damage-induced neuronal apoptosis. Despite the powerful pro-apoptotic effects of overexpressed Puma in Bax-expressing neurons, Bax nullizygous neurons were resistant to Puma-induced death. Therefore, Puma provides the critical link between p53 and Bax, and is both necessary and sufficient to mediate DNA damage-induced apoptosis of sympathetic neurons.
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Affiliation(s)
- Andreas Wyttenbach
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
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28
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Gong Y, Zhang Z. Alternative signaling pathways: when, where and why? FEBS Lett 2005; 579:5265-74. [PMID: 16194539 DOI: 10.1016/j.febslet.2005.08.062] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2005] [Revised: 08/29/2005] [Accepted: 08/30/2005] [Indexed: 11/24/2022]
Abstract
Alternative cell signal transduction pathways have been demonstrated in some experimental systems. The importance of their existence has not been completely appreciated. In this review we present the cases of alternative pathways resulted from a survey of the available experimental data. The alternative pathways could show different relationships, i.e., synergistic, redundant, additive, opposite and competitive effects. They could have distinct time courses and cell, organ, sex or species specification. Further, they could happen during physiological or pathological situations, and display differentiated sensitivity. These case studies together imply that alternative signal pathways could be involved in the regulation of cell functions at the pathway level. In-depth understanding of the importance of the alternative pathways will rely on building and exploration of mathematical models.
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Affiliation(s)
- Yunchen Gong
- Banting and Best Department of Medical Research, University of Toronto 112 College, Canada.
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29
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Wang Z, Sampath J, Fukuda S, Pelus LM. Disruption of the inhibitor of apoptosis protein survivin sensitizes Bcr-abl-positive cells to STI571-induced apoptosis. Cancer Res 2005; 65:8224-32. [PMID: 16166298 DOI: 10.1158/0008-5472.can-05-0303] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Bcr-abl oncogene induces hematopoietic cell transformation and protects cells from apoptosis; however, the mechanisms whereby Bcr-abl blocks apoptosis are poorly defined. We examined whether the inhibitor of apoptosis protein (IAP) family, in particular survivin, are regulated by Bcr-abl. Overexpression of Bcr-abl in Mo7e or BaF3 hematopoietic cells elevated survivin mRNA and protein concomitant with a 4-fold increase in survivin promoter activity. The region of the survivin promoter responding to Bcr-abl was narrowed down to a 116 bp fragment between nucleotides -1,194 and -1,078. The IAP family member IAP-like protein-2 was also up-regulated by Bcr-abl. Disruption of Bcr-abl in Bcr-abl-transduced BaF3 cells by small interfering RNA resulted in 3- to 4-fold reduction in survivin protein confirming the link between Bcr-abl and survivin. Survivin disruption in Bcr-abl-transduced Mo7e cells, or in K562 cells that endogenously express Bcr-abl, by transfection with dominant-negative or antisense survivin constructs promoted apoptosis induced by the Bcr-abl tyrosine kinase inhibitor STI571, which was accompanied by caspase-dependent cleavage of Bcr-abl, mitochondrial membrane potential disruption, and enhanced mitochondrial cytochrome c release. Although ectopic survivin protected K562 cells from apoptosis induced by STI571, it did not protect cells from apoptosis induced either by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) or the combination of TRAIL plus Hemin. Our results identify a new signal pathway downstream of Bcr-abl, in addition to the Bcl-2 family involved in the antiapoptotic effects of Bcr-abl, and suggest that anti-survivin therapy may have utility in patients with chronic myelogenous leukemia.
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MESH Headings
- Animals
- Antineoplastic Agents/pharmacology
- Apoptosis/drug effects
- Apoptosis/genetics
- Apoptosis Regulatory Proteins/pharmacology
- Benzamides
- Caspase 9
- Caspases/metabolism
- Cell Line, Tumor
- Cytochromes c/metabolism
- Fusion Proteins, bcr-abl/biosynthesis
- Fusion Proteins, bcr-abl/genetics
- Fusion Proteins, bcr-abl/physiology
- Hematopoietic Stem Cells/cytology
- Hematopoietic Stem Cells/drug effects
- Hematopoietic Stem Cells/physiology
- Humans
- Imatinib Mesylate
- Inhibitor of Apoptosis Proteins
- K562 Cells
- Leukemia, Megakaryoblastic, Acute/drug therapy
- Leukemia, Megakaryoblastic, Acute/genetics
- Leukemia, Megakaryoblastic, Acute/metabolism
- Leukemia, Megakaryoblastic, Acute/pathology
- Membrane Glycoproteins/pharmacology
- Mice
- Microtubule-Associated Proteins/antagonists & inhibitors
- Microtubule-Associated Proteins/biosynthesis
- Microtubule-Associated Proteins/genetics
- Neoplasm Proteins/antagonists & inhibitors
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Oligonucleotides, Antisense/genetics
- Piperazines/pharmacology
- Pyrimidines/pharmacology
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Signal Transduction
- Survivin
- TNF-Related Apoptosis-Inducing Ligand
- Transduction, Genetic
- Tumor Necrosis Factor-alpha/pharmacology
- Up-Regulation
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Affiliation(s)
- Zhanxiang Wang
- Department of Microbiology and Immunology and the Walther Oncology Center, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
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30
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Besirli CG, Wagner EF, Johnson EM. The limited role of NH2-terminal c-Jun phosphorylation in neuronal apoptosis: identification of the nuclear pore complex as a potential target of the JNK pathway. ACTA ACUST UNITED AC 2005; 170:401-11. [PMID: 16061693 PMCID: PMC2171472 DOI: 10.1083/jcb.200501138] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
c-Jun is induced in many neuronal death paradigms. A critical step in c-Jun regulation involves phosphorylation of Ser63/Ser73 located in the NH2-terminal transactivation domain. To determine the importance of this phosphorylation for neuronal apoptosis, we analyzed the sympathetic neurons of mice carrying a mutant c-Jun gene that lacks Ser63/Ser73 phosphorylation sites (jun aa). Trophic factor–deprivation or DNA damage–induced death was significantly delayed in jun aa/aa neurons. Neuronal c-Jun induction was only partially inhibited, demonstrating that phosphorylation of Ser63/73 is not required for c-Jun activation. The inductions of proapoptotic BH3-only proteins, Bim and PUMA/Bbc3, were delayed during neuronal apoptosis in mutant neurons. These results demonstrate that NH2-terminal c-Jun phosphorylation is important, but not necessary, for the induction of proapoptotic genes and neuronal apoptosis. Thus, additional JNK substrates may be critical for neuronal death. As potential mediators, we identified additional nuclear MLK/JNK substrates, including Nup214 subunit of the nuclear pore complex.
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Affiliation(s)
- Cagri G Besirli
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
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31
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Liu DX, Biswas SC, Greene LA. B-myb and C-myb play required roles in neuronal apoptosis evoked by nerve growth factor deprivation and DNA damage. J Neurosci 2005; 24:8720-5. [PMID: 15470138 PMCID: PMC6729960 DOI: 10.1523/jneurosci.1821-04.2004] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Activation of cell cycle elements plays a required role in neuronal apoptosis associated with both development and neurodegenerative disorders. We demonstrated previously that neuron survival requires gene repression mediated by the cell cycle transcription factor E2F (E2 promoter binding factor) and that apoptotic stimuli lead to de-repression of E2F-regulated genes and consequent death. However, the downstream mediators of such death have been unclear. The transcription factors B- and C-myb are E2F-regulated genes that are induced in neurons by apoptotic stimuli. Here, we examine the role of B- and C-myb induction in neuron death. Antisense and siRNA constructs that effectively block the upregulation of B- and C-myb provide substantial protection against death of cultured neuronal PC12 cells, sympathetic neurons, and cortical neurons elicited by either NGF withdrawal or DNA damage. There is also significant protection from death induced by direct E2F-dependent gene de-repression. Our findings thus establish required roles for B- and C-myb in neuronal apoptosis.
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Affiliation(s)
- David X Liu
- Department of Pathology, Center for Neurobiology and Behavior and Taub Center for Alzheimer's Disease Research, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA.
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32
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Lee AF, Ho DK, Zanassi P, Walsh GS, Kaplan DR, Miller FD. Evidence that DeltaNp73 promotes neuronal survival by p53-dependent and p53-independent mechanisms. J Neurosci 2005; 24:9174-84. [PMID: 15483136 PMCID: PMC6730077 DOI: 10.1523/jneurosci.1588-04.2004] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The p53 family member, p73, is essential for the survival of sympathetic neurons during the developmental period of naturally occurring neuronal death. Here, we have asked whether DeltaNp73, which is the only p73 isoform expressed in sympathetic neurons, mediates this survival by p53-dependent and/or p53-independent mechanisms. Initially, we used a genetic approach and crossed p53+/- and p73+/- mice. Quantitation of neurons in the sympathetic superior cervical ganglion during the period of naturally occurring cell death revealed that the loss of p53 partially rescued the death of neurons seen in p73-/- animals. Moreover, exogenous expression of DeltaNp73 in cultured p53-/- sympathetic neurons rescued these neurons from apoptosis after NGF withdrawal. Biochemical studies asking how DeltaNp73 inhibited NGF withdrawal-induced apoptosis in wild-type neurons demonstrated that it prevented the upregulation of the direct p53 targets p21 and Apaf-1 as well as cleavage of caspase-3. It also inhibited events at the mitochondrial apoptotic checkpoint, suppressing the induction of BimEL and the release of mitochondrial cytochrome c. Interestingly, DeltaNp73 expression also inhibited one very early event in the apoptotic cascade, the activation of c-Jun N-terminal protein kinase (JNK), likely by binding directly to JNK. Finally, we show that neuronal cell size is decreased in p73-/- mice, and that this decrease is not rescued by the lack of p53, suggesting a role for p73 in regulating cell size that does not involve interactions with p53. Thus, DeltaNp73 promotes neuronal survival via p53-dependent and -independent mechanisms, and it does so at multiple points, including some of the most proximal events that occur after NGF withdrawal.
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Affiliation(s)
- Anna F Lee
- Department of Developmental Biology, Hospital for Sick Children, Toronto, Ontario, M5G 1X8 Canada
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33
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Putcha GV, Johnson EM. Men are but worms: neuronal cell death in C elegans and vertebrates. Cell Death Differ 2004; 11:38-48. [PMID: 14647239 DOI: 10.1038/sj.cdd.4401352] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Awarding the 2002 Nobel Prize in Physiology or Medicine to Sydney Brenner, H Robert Horvitz, and John E Sulston for 'their discoveries concerning the genetic regulation of organ development and programmed cell death (PCD)' highlights the significant contribution that the study of experimental organisms, such as the nematode Caenorhabditis elegans, has made to our understanding of human physiology and pathophysiology. Their studies of lineage determination in worms established the 'central dogma' of apoptosis: The BH3-only protein EGL-1 is induced in cells destined to die, interacts with the BCL-2-like inhibitor CED-9, displacing the adaptor CED-4, which then promotes activation of the caspase CED-3. The vast majority of cells undergoing PCD during development in C. elegans, as in vertebrates, are neurons. Accordingly, the genetic regulation of apoptosis is strikingly similar in nematode and vertebrate neurons. This review summarizes these similarities - and the important differences - in the molecular mechanisms responsible for neuronal PCD in C. elegans and vertebrates, and examines the implications that our understanding of physiological neuronal apoptosis may have for the diagnosis and treatment of acute and chronic human neurodegenerative disorders.
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Affiliation(s)
- G V Putcha
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO 63110-1031, USA
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Frielingsdorf H, Schwarz K, Brundin P, Mohapel P. No evidence for new dopaminergic neurons in the adult mammalian substantia nigra. Proc Natl Acad Sci U S A 2004; 101:10177-82. [PMID: 15210991 PMCID: PMC454184 DOI: 10.1073/pnas.0401229101] [Citation(s) in RCA: 199] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A recent report by Zhao et al. [Zhao, M., Momma, S., Delfani, K., Carlen, M., Cassidy, R. M., Johansson, C. B., Brismar, H., Shupliakov, O., Frisen, J. & Janson, A. M. (2003) Proc. Natl. Acad. Sci. USA 100, 7925-7930] suggests that dopaminergic neurons, the cell type lost in Parkinson's disease, are continuously generated in the adult substantia nigra pars compacta. Using similar methodological procedures to label dividing cells, we found no evidence of new dopaminergic neurons in the substantia nigra, either in normal or 6-hydroxydopamine-lesioned hemi-Parkinsonian rodents, or even after growth factor treatment. Furthermore, we found no evidence of neural stem cells emanating from the cerebroventricular system and migrating to the substantia nigra. We conclude that it is unlikely that dopaminergic neurons are generated in the adult mammalian substantia nigra.
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Affiliation(s)
- Helena Frielingsdorf
- Section for Neuronal Survival, Wallenberg Neuroscience Center, BMC A-10, Lund University, SE-221 84 Lund, Sweden
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