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Advani D, Kumar P. Uncovering Cell Cycle Dysregulations and Associated Mechanisms in Cancer and Neurodegenerative Disorders: A Glimpse of Hope for Repurposed Drugs. Mol Neurobiol 2024:10.1007/s12035-024-04130-7. [PMID: 38532240 DOI: 10.1007/s12035-024-04130-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Accepted: 03/19/2024] [Indexed: 03/28/2024]
Abstract
The cell cycle is the sequence of events orchestrated by a complex network of cell cycle proteins. Unlike normal cells, mature neurons subsist in a quiescent state of the cell cycle, and aberrant cell cycle activation triggers neuronal death accompanied by neurodegeneration. The periodicity of cell cycle events is choreographed by various mechanisms, including DNA damage repair, oxidative stress, neurotrophin activity, and ubiquitin-mediated degradation. Given the relevance of cell cycle processes in cancer and neurodegeneration, this review delineates the overlapping cell cycle events, signaling pathways, and mechanisms associated with cell cycle aberrations in cancer and the major neurodegenerative disorders. We suggest that dysregulation of some common fundamental signaling processes triggers anomalous cell cycle activation in cancer cells and neurons. We discussed the possible use of cell cycle inhibitors for neurodegenerative disorders and described the associated challenges. We propose that a greater understanding of the common mechanisms driving cell cycle aberrations in cancer and neurodegenerative disorders will open a new avenue for the development of repurposed drugs.
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Affiliation(s)
- Dia Advani
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly Delhi College of Engineering), Shahbad Daulatpur, Bawana Road, New Delhi, Delhi, 110042, India
| | - Pravir Kumar
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly Delhi College of Engineering), Shahbad Daulatpur, Bawana Road, New Delhi, Delhi, 110042, India.
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2
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Yun HS, Lee J, Kim JY, Sim YJ, Lee CW, Park JK, Kim JS, Ahn J, Song JY, Baek JH, Hwang SG. A novel function of HRP-3 in regulating cell cycle progression via the HDAC-E2F1-Cyclin E pathway in lung cancer. Cancer Sci 2021; 113:145-155. [PMID: 34714604 PMCID: PMC8748221 DOI: 10.1111/cas.15183] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 10/06/2021] [Accepted: 10/12/2021] [Indexed: 11/29/2022] Open
Abstract
To improve the poor survival rate of lung cancer patients, we investigated the role of HDGF‐related protein 3 (HRP‐3) as a potential biomarker for lung cancer. The expression of endogenous HRP‐3 in human lung cancer tissues and xenograft tumor models is indicative of its clinical relevance in lung cancer. Additionally, we demonstrated that HRP‐3 directly binds to the E2F1 promoter on chromatin. Interestingly, HRP‐3 depletion in A549 cells impedes the binding of HRP‐3 to the E2F1 promoter; this in turn hampers the interaction between Histone H3/H4 and HDAC1/2 on the E2F1 promoter, while concomitantly inducing Histone H3/H4 acetylation around the E2F1 promoter. The enhanced Histone H3/H4 acetylation on the E2F1 promoter through HRP‐3 depletion increases the transcription level of E2F1. Furthermore, the increased E2F1 transcription levels lead to the enhanced transcription of Cyclin E, known as the E2F1‐responsive gene, thus inducing S‐phase accumulation. Therefore, our study provides evidence for the utility of HRP‐3 as a biomarker for the prognosis and treatment of lung cancer. Furthermore, we delineated the capacity of HRP‐3 to regulate the E2F1 transcription level via histone deacetylation.
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Affiliation(s)
- Hong Shik Yun
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Janet Lee
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Ju-Young Kim
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea.,Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Ye-Ji Sim
- Radiation Biology Research Team, Research Center, Dongnam Institute of Radiological and Medical Sciences, Busan, Korea
| | - Chang-Woo Lee
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Jong Kuk Park
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Jae-Sung Kim
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Jiyeon Ahn
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Jie-Young Song
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Jeong-Hwa Baek
- Radiation Biology Research Team, Research Center, Dongnam Institute of Radiological and Medical Sciences, Busan, Korea
| | - Sang-Gu Hwang
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
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Upadhyay A, Amanullah A, Chhangani D, Mishra R, Mishra A. Selective multifaceted E3 ubiquitin ligases barricade extreme defense: Potential therapeutic targets for neurodegeneration and ageing. Ageing Res Rev 2015; 24:138-59. [PMID: 26247845 DOI: 10.1016/j.arr.2015.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 06/24/2015] [Accepted: 07/30/2015] [Indexed: 12/24/2022]
Abstract
Efficient and regular performance of Ubiquitin Proteasome System and Autophagy continuously eliminate deleterious accumulation of nonnative protiens. In cellular quality control system, E3 ubiquitin ligases are significant employees for defense mechanism against abnormal toxic proteins. Few findings indicate that lack of functions of E3 ubiquitin ligases can be a causative factor of neurodevelopmental disorders, neurodegeneration, cancer and ageing. However, the detailed molecular pathomechanism implying E3 ubiquitin ligases in cellular functions in multifactorial disease conditions are not well understood. This article systematically represents the unique characteristics, molecular nature, and recent developments in the knowledge of neurobiological functions of few crucial E3 ubiquitin ligases. Here, we review recent literature on the roles of E6-AP, HRD1 and ITCH E3 ubiquitin ligases in the neuro-pathobiological mechanisms, with precise focus on the processes of neurodegeneration, and thereby propose new lines of potential targets for therapeutic interventions.
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Okoro DR, Arva N, Gao C, Polotskaia A, Puente C, Rosso M, Bargonetti J. Endogenous human MDM2-C is highly expressed in human cancers and functions as a p53-independent growth activator. PLoS One 2013; 8:e77643. [PMID: 24147044 PMCID: PMC3795673 DOI: 10.1371/journal.pone.0077643] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 09/12/2013] [Indexed: 01/22/2023] Open
Abstract
Human cancers over-expressing mdm2, through a T to G variation at a single nucleotide polymorphism at position 309 (mdm2 SNP309), have functionally inactivated p53 that is not effectively degraded. They also have high expression of the alternatively spliced transcript, mdm2-C. Alternatively spliced mdm2 transcripts are expressed in many forms of human cancer and when they are exogenously expressed they transform human cells. However no study to date has detected endogenous MDM2 protein isoforms. Studies with exogenous expression of splice variants have been carried out with mdm2-A and mdm2-B, but the mdm2-C isoform has remained virtually unexplored. We addressed the cellular influence of exogenously expressed MDM2-C, and asked if endogenous MDM2-C protein was present in human cancers. To detect endogenous MDM2-C protein, we created a human MDM2-C antibody to the splice junction epitope of exons four and ten (MDM2 C410) and validated the antibody with in vitro translated full length MDM2 compared to MDM2-C. Interestingly, we discovered that MDM2-C co-migrates with MDM2-FL at approximately 98 kDa. Using the validated C410 antibody, we detected high expression of endogenous MDM2-C in human cancer cell lines and human cancer tissues. In the estrogen receptor positive (ER+) mdm2 G/G SNP309 breast cancer cell line, T47D, we observed an increase in endogenous MDM2-C protein with estrogen treatment. MDM2-C localized to the nucleus and the cytoplasm. We examined the biological activity of MDM2-C by exogenously expressing the protein and observed that MDM2-C did not efficiently target p53 for degradation or reduce p53 transcriptional activity. Exogenous expression of MDM2-C in p53-null human cancer cells increased colony formation, indicating p53-independent tumorigenic properties. Our data indicate a role for MDM2-C that does not require the inhibition of p53 for increasing cancer cell proliferation and survival.
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Affiliation(s)
- Danielle R. Okoro
- Department of Biological Sciences Hunter College and The Graduate Center Departments of Biology and Biochemistry, City University of New York, New York City, United States of America
| | - Nicoleta Arva
- Department of Biological Sciences Hunter College and The Graduate Center Departments of Biology and Biochemistry, City University of New York, New York City, United States of America
| | - Chong Gao
- Department of Biological Sciences Hunter College and The Graduate Center Departments of Biology and Biochemistry, City University of New York, New York City, United States of America
| | - Alla Polotskaia
- Department of Biological Sciences Hunter College and The Graduate Center Departments of Biology and Biochemistry, City University of New York, New York City, United States of America
| | - Cindy Puente
- Department of Biological Sciences Hunter College and The Graduate Center Departments of Biology and Biochemistry, City University of New York, New York City, United States of America
| | - Melissa Rosso
- Department of Biological Sciences Hunter College and The Graduate Center Departments of Biology and Biochemistry, City University of New York, New York City, United States of America
| | - Jill Bargonetti
- Department of Biological Sciences Hunter College and The Graduate Center Departments of Biology and Biochemistry, City University of New York, New York City, United States of America
- * E-mail:
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Effects of Cymbopogon citratus and Ferula assa-foetida extracts on glutamate-induced neurotoxicity. In Vitro Cell Dev Biol Anim 2013; 49:706-15. [DOI: 10.1007/s11626-013-9656-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 06/24/2013] [Indexed: 12/27/2022]
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Yuan Z, Yao L, Li M, Liu S, He W, Lu Y. Opposing roles for E2F1 in survival and death of cerebellar granule neurons. Neurosci Lett 2011; 499:164-9. [PMID: 21641965 DOI: 10.1016/j.neulet.2011.05.045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Revised: 05/17/2011] [Accepted: 05/18/2011] [Indexed: 11/30/2022]
Abstract
The transcription factor E2F1 is upregulated when cerebellar granular neurons (CGNs) undergo apoptosis under potassium deprivation. In this study, we examined the effects of E2F1 upregulation on the survival and death of CGNs isolated from C57 mice and Sprague-Dawley (SD) rats. Plasmid- and adenovirus-mediated expression of E2F1 dose-dependently induced apoptosis in mouse CGNs but unexpectedly failed to induce apoptosis in rat CGNs. Caspase 3, a marker for neuronal apoptosis, was significantly activated by ectopic E2F1 expression in mouse CGNs but not in rat CGNs. Furthermore, overexpression of E2F1 significantly promoted apoptotic progression in mouse CGNs following potassium deprivation but attenuated apoptosis in rat CGNs, whereas E2F1 lacking DNA binding ability (E2F1-M132) lost its pro-apoptotic role in mouse CGNs and anti-apoptotic role in rat CGNs. Together, our results demonstrated that upregulation of E2F1 by potassium deprivation promotes apoptosis in C57 mouse CGNs but antagonizes apoptosis in SD rat CGNs, suggesting opposing roles for E2F1 in regulating CGN fate.
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Affiliation(s)
- Zhongmin Yuan
- Department of Neurosurgery, Institute of Neuroscience, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China.
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Zhong Z, Wang Y, Guo H, Sagare A, Fernández JA, Bell RD, Barrett TM, Griffin JH, Freeman RS, Zlokovic BV. Protein S protects neurons from excitotoxic injury by activating the TAM receptor Tyro3-phosphatidylinositol 3-kinase-Akt pathway through its sex hormone-binding globulin-like region. J Neurosci 2010; 30:15521-34. [PMID: 21084607 PMCID: PMC3012432 DOI: 10.1523/jneurosci.4437-10.2010] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 09/15/2010] [Indexed: 11/21/2022] Open
Abstract
The anticoagulant factor protein S (PS) protects neurons from hypoxic/ischemic injury. However, molecular mechanisms mediating PS protection in injured neurons remain unknown. Here, we show mouse recombinant PS protects dose-dependently mouse cortical neurons from excitotoxic NMDA-mediated neuritic bead formation and apoptosis by activating the phosphatidylinositol 3-kinase (PI3K)-Akt pathway (EC(50) = 26 ± 4 nm). PS stimulated phosphorylation of Bad and Mdm2, two downstream targets of Akt, which in neurons subjected to pathological overstimulation of NMDA receptors (NMDARs) increased the antiapoptotic Bcl-2 and Bcl-X(L) levels and reduced the proapoptotic p53 and Bax levels. Adenoviral transduction with a kinase-deficient Akt mutant (Ad.Akt(K179A)) resulted in loss of PS-mediated neuronal protection, Akt activation, and Bad and Mdm2 phosphorylation. Using the TAM receptors tyrosine kinases Tyro3-, Axl-, and Mer-deficient neurons, we showed that PS protected neurons lacking Axl and Mer, but not Tyro3, suggesting a requirement of Tyro3 for PS-mediated protection. Consistent with these results, PS dose-dependently phosphorylated Tyro3 on neurons (EC(50) = 25 ± 3 nm). In an in vivo model of NMDA-induced excitotoxic lesions in the striatum, PS dose-dependently reduced the lesion volume in control mice (EC(50) = 22 ± 2 nm) and protected Axl(-/-) and Mer(-/-) transgenic mice, but not Tyro3(-/-) transgenic mice. Using different structural PS analogs, we demonstrated that the C terminus sex hormone-binding globulin-like (SHBG) domain of PS is critical for neuronal protection in vitro and in vivo. Thus, our data show that PS protects neurons by activating the Tyro3-PI3K-Akt pathway via its SHGB domain, suggesting potentially a novel neuroprotective approach for acute brain injury and chronic neurodegenerative disorders associated with excessive activation of NMDARs.
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Affiliation(s)
- Zhihui Zhong
- Center for Neurodegenerative and Vascular Brain Disorders, Department of Neurosurgery and Neurology, and
| | - Yaoming Wang
- Center for Neurodegenerative and Vascular Brain Disorders, Department of Neurosurgery and Neurology, and
| | - Huang Guo
- Center for Neurodegenerative and Vascular Brain Disorders, Department of Neurosurgery and Neurology, and
| | - Abhay Sagare
- Center for Neurodegenerative and Vascular Brain Disorders, Department of Neurosurgery and Neurology, and
| | - José A. Fernández
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - Robert D. Bell
- Center for Neurodegenerative and Vascular Brain Disorders, Department of Neurosurgery and Neurology, and
| | - Theresa M. Barrett
- Center for Neurodegenerative and Vascular Brain Disorders, Department of Neurosurgery and Neurology, and
| | - John H. Griffin
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - Robert S. Freeman
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York 14642, and
| | - Berislav V. Zlokovic
- Center for Neurodegenerative and Vascular Brain Disorders, Department of Neurosurgery and Neurology, and
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Dupuis L, Pehar M, Cassina P, Rene F, Castellanos R, Rouaux C, Gandelman M, Dimou L, Schwab ME, Loeffler JP, Barbeito L, Gonzalez de Aguilar JL. Nogo receptor antagonizes p75NTR-dependent motor neuron death. Proc Natl Acad Sci U S A 2008; 105:740-5. [PMID: 18182498 PMCID: PMC2206606 DOI: 10.1073/pnas.0703842105] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2007] [Indexed: 11/18/2022] Open
Abstract
The Nogo-66 receptor (NgR) plays a critical role in restricting axon regeneration in the central nervous system. This inhibitory action is in part mediated by a neuronal receptor complex containing p75NTR, a multifunctional receptor also well known to trigger cell death upon binding to neurotrophins such as NGF. In the present study, we show that Pep4 and NEP1-40, which are two peptides derived from the Nogo-66 sequence that modulate NgR-mediated neurite outgrowth inhibition, prevent NGF-stimulated p75NTR-dependent death of cultured embryonic motor neurons. They also confer protection on spinal cord motor neurons after neonatal sciatic nerve axotomy. These findings demonstrate an as-yet-unknown function of NgR in maintaining neuronal survival that may be relevant for motor neuron development and degeneration.
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Affiliation(s)
- Luc Dupuis
- *Institut National de la Santé et de la Recherche Médicale, U692, Laboratoire de Signalisations Moléculaires et Neurodégénérescence, Strasbourg, F-67085 France
- Université Louis Pasteur, Faculté de Médecine, UMRS692, Strasbourg, F-67085 France
| | - Mariana Pehar
- Departamento de Neurobiología Celular, Institut Pasteur, Montevideo, 11600 Uruguay
| | - Patricia Cassina
- Faculdad de Medicina, Universidad de la República, Montevideo, 11800 Uruguay; and
| | - Frédérique Rene
- *Institut National de la Santé et de la Recherche Médicale, U692, Laboratoire de Signalisations Moléculaires et Neurodégénérescence, Strasbourg, F-67085 France
- Université Louis Pasteur, Faculté de Médecine, UMRS692, Strasbourg, F-67085 France
| | - Raquel Castellanos
- Faculdad de Medicina, Universidad de la República, Montevideo, 11800 Uruguay; and
| | - Caroline Rouaux
- *Institut National de la Santé et de la Recherche Médicale, U692, Laboratoire de Signalisations Moléculaires et Neurodégénérescence, Strasbourg, F-67085 France
- Université Louis Pasteur, Faculté de Médecine, UMRS692, Strasbourg, F-67085 France
| | - Mandi Gandelman
- Departamento de Neurobiología Celular, Institut Pasteur, Montevideo, 11600 Uruguay
| | - Leda Dimou
- Brain Research Institute, University of Zurich and Department of Biology, Eidgenössiche Technische Hochschule, Zurich, 8057 Switzerland
| | - Martin E. Schwab
- Brain Research Institute, University of Zurich and Department of Biology, Eidgenössiche Technische Hochschule, Zurich, 8057 Switzerland
| | - Jean-Philippe Loeffler
- *Institut National de la Santé et de la Recherche Médicale, U692, Laboratoire de Signalisations Moléculaires et Neurodégénérescence, Strasbourg, F-67085 France
- Université Louis Pasteur, Faculté de Médecine, UMRS692, Strasbourg, F-67085 France
| | - Luis Barbeito
- Departamento de Neurobiología Celular, Institut Pasteur, Montevideo, 11600 Uruguay
| | - Jose-Luis Gonzalez de Aguilar
- *Institut National de la Santé et de la Recherche Médicale, U692, Laboratoire de Signalisations Moléculaires et Neurodégénérescence, Strasbourg, F-67085 France
- Université Louis Pasteur, Faculté de Médecine, UMRS692, Strasbourg, F-67085 France
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Benosman S, Gross I, Clarke N, Jochemsen AG, Okamoto K, Loeffler JP, Gaiddon C. Multiple neurotoxic stresses converge on MDMX proteolysis to cause neuronal apoptosis. Cell Death Differ 2007; 14:2047-57. [PMID: 17823617 DOI: 10.1038/sj.cdd.4402216] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
MDMX has been shown to modulate p53 in dividing cells after DNA damage. In this study, we investigated the role of MDMX in primary cultures of neurons undergoing cell death. We found that DNA damage, but also membrane-initiated apoptotic stresses (glutamate receptor; Amyloid beta precursor) or survival factor deprivation downregulated MDMX protein levels. Forced downregulation of murine double minute X (MDMX) by shRNA induced apoptosis suggesting that MDMX is required for survival in neurons. Protease inhibitors prevented the loss of MDMX after neurotoxic treatments, indicating a regulation of protein stability. Some, but not all, neurotoxic stresses induced phosphorylation of MDMX at serine 367, further supporting regulation at the protein level. Interestingly, we found that depending on the stimulus either p53 or E2F1 was induced, but overexpression of MDMX inhibited the transcriptional activity of both proapoptotic factors, and maintained neuronal viability upon neurotoxic stresses. Taken together, our data show that MDMX is an antiapoptotic factor in neurons, whose degradation is induced by various stresses and allows activation of p53 and E2F-1 during neuronal apoptosis.
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Affiliation(s)
- S Benosman
- INSERM U692, Laboratoire de Signalisations Moléculaires et Neurodégénérescence, Université Louis Pasteur, Faculté de Médecine, UMRS692, Strasbourg, France
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10
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Yuan Z, Mei Y, Zhou J, Tan M, Song B, Ma C, Ying C, Li D, Ching YP, Li M. E2F1 is not essential for apoptosis induced by potassium deprivation in cerebellar granule neurons. Neurosci Lett 2007; 424:155-9. [PMID: 17728064 DOI: 10.1016/j.neulet.2007.07.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Revised: 06/29/2007] [Accepted: 07/01/2007] [Indexed: 01/27/2023]
Abstract
Cerebellar granule neurons (CGNs) undergo apoptosis when deprived of depolarizing concentration of potassium. A key regulator of cell cycle, E2F1, was believed to play a role in CGN apoptosis induced by potassium deprivation. However, here we demonstrated that although E2F1 was upregulated in wild type CGNs following potassium deprivation, CGNs that derived from E2F1 knockout mice underwent apoptosis at a similar rate as the wild type. Analysis of the apoptotic neurons revealed no difference in the activation of caspase-3 in E2F1 null and wild type CGNs. Furthermore, knockdown of E2F1 expression by RNA interference failed to attenuate the apoptosis of CGNs induced by potassium deprivation. Taken together, our results suggested that E2F1 is not essential for apoptosis induced by potassium deprivation in CGNs.
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Affiliation(s)
- Zhongmin Yuan
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, 74 Zhongshan Road II, Guangzhou 510080, China
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11
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Yeste-Velasco M, Folch J, Trullàs R, Abad MA, Enguita M, Pallàs M, Camins A. Glycogen synthase kinase-3 is involved in the regulation of the cell cycle in cerebellar granule cells. Neuropharmacology 2007; 53:295-307. [PMID: 17612578 DOI: 10.1016/j.neuropharm.2007.05.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2006] [Revised: 04/02/2007] [Accepted: 05/16/2007] [Indexed: 01/17/2023]
Abstract
Recent studies have demonstrated that neuronal reentry in the cell cycle and specifically the expression of the transcription factor E2F-1, constitutes a pathway that may be involved in neuronal apoptosis after serum and potassium withdrawal. Other enzymes such as glycogen synthase kinase-3beta (GSK-3beta) are also involved in this apoptotic stimulus, and thus in the process of neuronal cell death. Primary cerebellar granule cells (CGNs) were used in this study to determine whether pharmacological inhibition of GSK-3beta is involved in neuronal modulation of the cell cycle, and specifically in the regulation of E2F-1 and retinoblastoma protein (Rb). CGNs showed a dramatic increase in GSK-3beta activity after 2h of serum and potassium deprivation. Immunoblot and activity assays revealed that lithium and SB415286 inhibit fully the activation of GSK-3beta and attenuate the expression of cyclin D, cyclin E, pRb phosphorylation and the transcription factor E2F-1. These data were confirmed using AR-014418, a selective GSK-3beta inhibitor that prevents the expression of cell-cycle proteins. Our data indicate that GSK-3beta inhibition regulates, in part, the cell cycle in CGNs by inhibiting Rb phosphorylation and thus inhibiting E2F-1 activity. However, the selective inhibition of GSK-3beta with AR-A014418 had not effect on cell viability or apoptosis mediated by S/K withdrawal. Furthermore, our results suggest that selective GSK-3beta inhibition is not sufficient to protect against apoptosis in this S/K withdrawal model, indicating that Li(+) and SB415286 neuroprotective effects are mediated by the inhibition of additional targets to GSK3beta. Therefore, there is a connection between cell cycle and GSK-3beta activation and that these, along with other mechanisms, are involved in the molecular paths leading to the apoptotic process of rat CGNs triggered by S/K withdrawal.
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Affiliation(s)
- M Yeste-Velasco
- Unitat de Farmacologia, Facultat de Farmàcia Universitat de Barcelona, Nucli Universitari de Pedralbes, E-08028 Barcelona, Spain
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12
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Yu F, Megyesi J, Safirstein RL, Price PM. Involvement of the CDK2-E2F1 pathway in cisplatin cytotoxicity in vitro and in vivo. Am J Physiol Renal Physiol 2007; 293:F52-9. [PMID: 17459956 DOI: 10.1152/ajprenal.00119.2007] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
E2F1 is a key regulator that links cell cycle progression and cell death. E2F1 activity is controlled by Cdk2-cyclin complexes via several mechanisms, such as phosphorylation of retinoblastoma protein (pRb) to release E2F1, direct phosphorylation, and stable physical interaction. We have demonstrated that cisplatin cytotoxicity depends on Cdk2 activity, and Cdk2 inhibition protects kidney cells from cisplatin-induced cell death in vitro and in vivo. Now we show that E2F1 is an important downstream effector of Cdk2 that accumulates in mouse kidneys and in cultured mouse proximal tubular cells (TKPTS) after cisplatin exposure by a Cdk2-dependent mechanism. Direct inhibition of E2F1 by transduction with adenoviruses expressing an E2F1-binding protein (TopBP1) protected TKPTS cells from cisplatin-induced apoptosis, whereas overexpression of E2F1 caused cell death. Moreover, E2F1 knockout mice were markedly protected against cisplatin nephrotoxicity by both functional and histological criteria. Collectively, cisplatin-induced cell death is dependent on Cdk2 activity, which is at least partly through the Cdk2-E2F1 pathway both in vitro and in vivo.
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Affiliation(s)
- Fang Yu
- Dept. of Internal Medicine, University of Arkansas for Medical Sciences, Little Rock, USA
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13
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Höglinger GU, Breunig JJ, Depboylu C, Rouaux C, Michel PP, Alvarez-Fischer D, Boutillier AL, DeGregori J, Oertel WH, Rakic P, Hirsch EC, Hunot S. The pRb/E2F cell-cycle pathway mediates cell death in Parkinson's disease. Proc Natl Acad Sci U S A 2007; 104:3585-90. [PMID: 17360686 PMCID: PMC1805567 DOI: 10.1073/pnas.0611671104] [Citation(s) in RCA: 200] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The mechanisms leading to degeneration of dopaminergic neurons (DNs) in the substantia nigra of patients with Parkinson's disease (PD) are not completely understood. Here, we show, in the postmortem human tissue, that these neurons aberrantly express mitosis-associated proteins, including the E2F-1 transcription factor, and appear to duplicate their nuclear DNA. We further demonstrate that the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine injected into mice and application of its active metabolite 1-methyl-4-phenylpyridinium to mesencephalic cultures activate the retinoblastoma-E2F pathway in postmitotic DNs. We also find that cell death rather than mitotic division followed the toxin-induced replication of DNA, as determined by BrdU incorporation in DNs. In addition, blocking E2F-1 transcription protected cultured DNs against 1-methyl-4-phenylpyridinium toxicity. Finally, E2F-1-deficient mice were significantly more resistant to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced dopaminergic cell death than their wild-type littermates. Altogether, BrdU incorporation in mature neurons and lack of evidence for newborn neurons argue against neuronal turnover in normal conditions or during pathological states in the substantia nigra. Instead, our results demonstrate that mitosis-like signals are activated in mature DNs in patients with PD and mediate neuronal death in experimental models of the disease. Inhibition of mitosis-like signals may therefore provide strategies for neuroprotection in PD.
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Affiliation(s)
- Günter U. Höglinger
- *Department of Experimental Neurology, Philipps University, 35039 Marburg, Germany
- Department of Experimental Neurology and Therapeutics, Unité Mixte de Recherche 679, Institut National de la Santé et de la Recherche Médicale, 75013 Paris, France
- Faculté de Médecine, Unité Mixte de Recherche 679, Université Pierre et Marie Curie-Paris, 75013 Paris, France
- To whom correspondence may be addressed. E-mail: , , or
| | - Joshua J. Breunig
- Department of Neurobiology, Yale University School of Medicine, and
- Kavli Institute for Neuroscience, Yale University, New Haven, CT 06510
| | - Candan Depboylu
- *Department of Experimental Neurology, Philipps University, 35039 Marburg, Germany
| | - Caroline Rouaux
- **Laboratoire de Signalisations Moléculaires et Neurodegenerescence, Unité Mixte de Recherche 692, Institut National de la Santé et de la Recherche Médicale, F-67085 Strasbourg, France; and
| | - Patrick P. Michel
- Department of Experimental Neurology and Therapeutics, Unité Mixte de Recherche 679, Institut National de la Santé et de la Recherche Médicale, 75013 Paris, France
- Faculté de Médecine, Unité Mixte de Recherche 679, Université Pierre et Marie Curie-Paris, 75013 Paris, France
| | | | - Anne-Laurence Boutillier
- **Laboratoire de Signalisations Moléculaires et Neurodegenerescence, Unité Mixte de Recherche 692, Institut National de la Santé et de la Recherche Médicale, F-67085 Strasbourg, France; and
| | - James DeGregori
- Department of Biochemistry and Molecular Genetics, University of Colorado, Denver, CO 80262
| | - Wolfgang H. Oertel
- *Department of Experimental Neurology, Philipps University, 35039 Marburg, Germany
| | - Pasko Rakic
- Department of Neurobiology, Yale University School of Medicine, and
- Kavli Institute for Neuroscience, Yale University, New Haven, CT 06510
- To whom correspondence may be addressed. E-mail: , , or
| | - Etienne C. Hirsch
- Department of Experimental Neurology and Therapeutics, Unité Mixte de Recherche 679, Institut National de la Santé et de la Recherche Médicale, 75013 Paris, France
- Faculté de Médecine, Unité Mixte de Recherche 679, Université Pierre et Marie Curie-Paris, 75013 Paris, France
| | - Stéphane Hunot
- Department of Experimental Neurology and Therapeutics, Unité Mixte de Recherche 679, Institut National de la Santé et de la Recherche Médicale, 75013 Paris, France
- Faculté de Médecine, Unité Mixte de Recherche 679, Université Pierre et Marie Curie-Paris, 75013 Paris, France
- To whom correspondence may be addressed. E-mail: , , or
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14
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Zhang Y, Qu D, Morris EJ, O’Hare MJ, Callaghan SM, Slack RS, Geller HM, Park DS. The Chk1/Cdc25A pathway as activators of the cell cycle in neuronal death induced by camptothecin. J Neurosci 2006; 26:8819-28. [PMID: 16928871 PMCID: PMC6674376 DOI: 10.1523/jneurosci.2593-06.2006] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Cell cycle regulators appear to play a paradoxical role in neuronal death. We have shown previously that cyclin-dependent kinases (CDKs), along with their downstream effectors, Rb (retinoblastoma) and E2F/DP1 (E2 promoter binding factor/deleted in polyposis 1), regulate neuronal death evoked by the DNA damaging agent camptothecin. However, the mechanism by which CDKs are activated in this model is unclear. The cell division cycle 25A (Cdc25A) phosphatase is a critical regulator of cell cycle CDKs in proliferating cells. In cortical neurons, we presently show that expression of Cdc25A promotes death even in the absence of DNA damage. Importantly, Cdc25A activity is rapidly increased during DNA damage treatment. Inhibition of Cdc25A blocks death and reduces cyclin D1-associated kinase activity and Rb phosphorylation. This indicates that endogenous Cdc25A activity is important for regulation of cell cycle-mediated neuronal death. We also examined how Cdc25A activity is regulated after DNA damage. Cultured embryonic cortical neurons have a significant basal activity of checkpoint kinase 1 (Chk1), a kinase that regulates cell cycle arrest. During camptothecin treatment of neurons, this activity is rapidly downregulated with a concomitant increase in Cdc25A activity. Importantly, expression of wild-type Chk1, but not kinase-dead Chk1, inhibits the camptothecin-induced increase in Cdc25A activity. In addition, Chk1 expression also promotes survival in the presence of the DNA-damaging agent. Together, our data suggest that a Chk1/Cdc25A activity participates in activation of a cell cycle pathway-mediated death signal in neurons. These data also define how a proliferative signal may be abnormally activated in a postmitotic environment.
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Affiliation(s)
- Yi Zhang
- Ottawa Health Research Institute, Neuroscience Group, University of Ottawa, Ottawa, Ontario, Canada, K1H 8M5
| | - Dianbo Qu
- Ottawa Health Research Institute, Neuroscience Group, University of Ottawa, Ottawa, Ontario, Canada, K1H 8M5
| | - Erick J. Morris
- Laboratory of Molecular Oncology, Massachusetts General Hospital Cancer Center, Charlestown, Massachusetts 02129
| | - Michael J. O’Hare
- Ottawa Health Research Institute, Neuroscience Group, University of Ottawa, Ottawa, Ontario, Canada, K1H 8M5
| | - Steven M. Callaghan
- Ottawa Health Research Institute, Neuroscience Group, University of Ottawa, Ottawa, Ontario, Canada, K1H 8M5
| | - Ruth S. Slack
- Ottawa Health Research Institute, Neuroscience Group, University of Ottawa, Ottawa, Ontario, Canada, K1H 8M5
| | - Herbert M. Geller
- Division of Intramural Research, National Heart Lung and Blood Institute, National Institute of Health, Bethesda, Maryland 20892, and
| | - David S. Park
- Ottawa Health Research Institute, Neuroscience Group, University of Ottawa, Ottawa, Ontario, Canada, K1H 8M5
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15
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Buckwalter MS, Yamane M, Coleman BS, Ormerod BK, Chin JT, Palmer T, Wyss-Coray T. Chronically increased transforming growth factor-beta1 strongly inhibits hippocampal neurogenesis in aged mice. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 169:154-64. [PMID: 16816369 PMCID: PMC1698757 DOI: 10.2353/ajpath.2006.051272] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
There is increasing evidence that hippocampal learning correlates strongly with neurogenesis in the adult brain. Increases in neurogenesis after brain injury also correlate with improved outcomes. With aging the capacity to generate new neurons decreases dramatically, both under normal conditions and after injury. How this decrease occurs is not fully understood, but we hypothesized that transforming growth factor (TGF)-beta1, a cell cycle regulator that rapidly increases after injury and with age, might play a role. We found that chronic overproduction of TGF-beta1 from astrocytes almost completely blocked the generation of new neurons in aged transgenic mice. Even young adult TGF-beta1 mice had 60% fewer immature, doublecortin-positive, hippocampal neurons than wild-type littermate controls. Bromodeoxyuridine labeling of dividing cells in 2-month-old TGF-beta1 mice confirmed this decrease in neuro-genesis and revealed a similar decrease in astrogenesis. Treatment of early neural progenitor cells with TGF-beta1 inhibited their proliferation. This strongly suggests that TGF-beta1 directly affects these cells before their differentiation into neurons and astrocytes. Together, these data show that TGF-beta1 is a potent inhibitor of hippocampal neural progenitor cell proliferation in adult mice and suggest that it plays a key role in limiting injury and age-related neurogenesis.
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Affiliation(s)
- Marion S Buckwalter
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, SUMC Rm. 343A, Stanford, CA 94305-5235, USA
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16
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Abstract
The inappropriate expression/activation of cell-cycle-related molecules is associated with neuron death in many experimental paradigms and human neuropathologic conditions. However, the means whereby this links to the core apoptotic machinery in neurons have been unclear. Here, we show that the pro-apoptotic Bcl-2 homology 3 domain-only molecule Bcl-2 interacting mediator of cell death (Bim) is a target of a cell-cycle-related apoptotic pathway in neuronal cells. Induction of Bim in NGF-deprived cells requires expression and activity of cyclin-dependent kinase 4 (cdk4) and consequent de-repression of E2 promoter binding factor (E2F)-regulated genes including members of the myb transcription factor family. The Bim promoter contains two myb binding sites, mutation of which abolishes induction of a Bim promoter-driven reporter by NGF deprivation or E2F-dependent gene de-repression. NGF deprivation significantly increases endogenous levels of C-myb and its occupancy of the endogenous Bim promoter. These findings support a model in which apoptotic stimuli lead to cdk4 activation, consequent de-repression of E2F-regulated mybs, and induction of pro-apoptotic Bim.
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Affiliation(s)
- Subhas C Biswas
- Department of Pathology, Center for Neurobiology and Behavior, Taub Center for Alzheimer's Disease Research, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA.
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17
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Newsom RSB, Johnston R, Sullivan PM, Aylward GB, Holder GE, Gregor ZJ. SUDDEN VISUAL LOSS AFTER REMOVAL OF SILICONE OIL. Retina 2004; 24:871-7. [PMID: 15579983 DOI: 10.1097/00006982-200412000-00005] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
PURPOSE Removal of silicone oil after vitreoretinal surgery reduces potential complications of glaucoma and cataract and improves visual function in 30% of patients. We report the clinical findings of a series of patients who experienced unexpected and permanent visual loss after removal of silicone oil. METHODS Seven patients with visual loss after removal of silicon oil were investigated with best-corrected Snellen visual acuity (BCVA) assessment, fundus biomicroscopy, fluorescein angiography, optical coherence tomography, and electrophysiologic examination. RESULTS Six men and one woman (average age, 42.8 years.) presented with profound BCVA loss, averaging 4.7 Snellen lines (SD 1.4), after silicon oil removal. No other complications associated with oil removal were noted. The retina remained attached in all cases, no patient developed cystoid macular edema or epiretinal membrane, and optical coherence tomographic and fluorescein angiographic findings remained normal. Electrodiagnostic testing showed a range of abnormalities, with the majority of patients showing severe macular dysfunction. CONCLUSIONS We describe a new phenomenon of unexpected visual loss after oil removal in patients with good visual potential. The pathogenesis remains obscure.
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Affiliation(s)
- Richard S B Newsom
- Department of Vitreoretinal Surgery, Moorfields Eye Hospital, London, England
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18
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Panteleeva I, Rouaux C, Larmet Y, Boutillier S, Loeffler JP, Boutillier AL. HDAC-3 Participates in the Repression ofe2f-Dependent Gene Transcription in Primary Differentiated Neurons. Ann N Y Acad Sci 2004; 1030:656-60. [PMID: 15659849 DOI: 10.1196/annals.1329.076] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Activation of e2f-1 gene expression is an event that has been now established in many models of neuronal apoptosis. Accumulated E2F-1 protein has also been observed in post mortem brains obtained from patients suffering from different neurodegenerative diseases. We have previously shown in primary neuronal cultures that e2f-1 gene transcription was actively repressed in neuroprotective conditions through HDAC-dependent regulation on the E2F-responsive elements (E2F-REs) located in the e2f-1 gene promoter. Here, we further investigated the protein complex bound to these sites by gel shift analysis. We found that the specific protein binding to E2F-REs is altered in apoptotic conditions compared to neuroprotective conditions, suggesting that the proteic constituents of the complex are likely to be modified upon apoptosis onset. Indeed, Western blot analysis showed a time-dependent degradation of the Rb/E2F binding protein HDAC-3 during apoptosis, a degradation that is caspase-dependent. Altogether, these data point to HDAC-3 as a good candidate involved in the active e2f-1 repression necessary for neuroprotection.
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Affiliation(s)
- Irina Panteleeva
- Laboratoire de Signalisation Moleculaire et Neurodegenerescence, EA#3433, Faculté de Médecine, 11 rue Humann, 67085 Strasbourg cedex, France
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19
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Greene LA, Biswas SC, Liu DX. Cell cycle molecules and vertebrate neuron death: E2F at the hub. Cell Death Differ 2004; 11:49-60. [PMID: 14647236 DOI: 10.1038/sj.cdd.4401341] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Vertebrate neuron cell death is both a normal developmental process and the catastrophic outcome of nervous system trauma or degenerative disorders. Although the mechanisms of such death include an evolutionarily conserved core apoptotic pathway that is highly homologous to that first described by Horvitz and co-workers in Caenorhabditis elegans, it appears that many instances of neuron death additionally require the transcription-dependent induction of proapoptotic molecules. One such proapoptotic transcriptional pathway revealed by studies over the past decade revolves about the transcription factor E2F and those molecules that either regulate E2F activity or that are direct or indirect transcriptional targets of E2F. Many of the molecules associated with the E2F apoptotic pathway in postmitotic neurons also participate in the cell cycle in proliferating cells. Observations in human material and in animal and cell culture models show widespread correlation between changes in expression, activity and subcellular localization of E2F-related cell cycle molecules and developmental and catastrophic neuron death. A variety of experimental approaches support a causal role for such changes in the death process and are beginning to indicate how the neuronal E2F pathway activates the core apoptotic machinery. The discovery and elaboration of the neuronal apoptotic E2F pathway provides abundant targets as well as small molecule candidates for potential therapeutic intervention in nervous system trauma and degenerative disease.
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Affiliation(s)
- L A Greene
- Department of Pathology, Columbia University College of Physicians and Surgeons, New York 10032, USA.
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20
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Verdaguer E, Jordá EG, Canudas AM, Jiménez A, Pubill D, Escubedo E, Camarasa J, Pallàs M, Camins A. Antiapoptotic effects of roscovitine in cerebellar granule cells deprived of serum and potassium: a cell cycle-related mechanism. Neurochem Int 2004; 44:251-61. [PMID: 14602088 DOI: 10.1016/s0197-0186(03)00147-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Neuronal apoptosis may be partly due to inappropriate control of the cell cycle. We used serum deprivation as stimulus and reduced potassium from 25 to 5mM (S/K deprivation), which induces apoptosis in cerebellar granule neurons (CGNs), to evaluate the direct correlation between re-entry in the cell cycle and apoptosis. Roscovitine (10 microM), an antitumoral drug that inhibits cyclin-dependent kinase 1 (cdk1), cdk2 and cdk5, showed a significant neuroprotective effect on CGNs deprived of S/K. S/K deprivation induced the expression of cell cycle proteins such as cyclin E, cyclin A, cdk2, cdk4 and E2F-1. It also caused CGNs to enter the S phase of the cell cycle, measured by a significant incorporation of BrdU (30% increase over control cells), which was reduced in the presence of roscovitine (10 microM). On the other hand, roscovitine modified the expression of cytochrome c (Cyt c), Bcl-2 and Bax, which are involved in the apoptotic intrinsic pathway induced by S/K deprivation. We suggest that the antiapoptotic effects of roscovitine on CGNs are due to its anti-proliferative efficacy and to an action on the mitochondrial apoptotic mechanism.
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Affiliation(s)
- Ester Verdaguer
- Unitat de Farmacologia i Farmacognòsia, Facultat de Farmàcia, Universitat de Barcelona, Nucli Universitari de Pedralbes, E-08028 Barcelona, Spain
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21
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Barbato C, Corbi N, Canu N, Fanciulli M, Serafino A, Ciotti M, Libri V, Bruno T, Amadoro G, De Angelis R, Calissano P, Passananti C. Rb binding protein Che-1 interacts with Tau in cerebellar granule neurons. Modulation during neuronal apoptosis. Mol Cell Neurosci 2004; 24:1038-50. [PMID: 14697667 DOI: 10.1016/j.mcn.2003.08.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Che-1 is a recently identified human Rb binding protein that inhibits the Rb growth-suppressing function and regulates cell proliferation. Che-1 contacts the Rb and competes with HDAC1 for Rb-binding site, removing HDAC1 from the Rb/E2F cell cycle-regulated promoters. We have investigated the expression of Che-1 in neuronal cells and we showed that Che-1 directly interacts with Tau. Tau is a microtubule-associated protein involved in the assembly and stabilization of neuronal microtubules network that plays a crucial role modulating neuronal morphogenesis, axonal shape, and transport. In rat cerebellar granule neurons (CGNs) Che-1 partially colocalizes with Tau in the cytoplasm. Che-1 binds the amino-terminal region of Tau protein, which is not involved in microtubule interactions. Tau and Che-1 endogenous proteins coimmunoprecipitate from CGNs cellular lysates. In addition, Che-1/Tau interaction was demonstrated both in overexpressing COS-7 cells and CGNs by FRET analysis. Finally, we observed that Tau/Che-1 interaction is modulated during neuronal apoptosis.
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Affiliation(s)
- Christian Barbato
- Istituto di Neurobiologia e Medicina Molecolare, CNR, Viale Marx 43, 00137 Rome, Italy
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22
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Verdaguer E, Jordà EG, Canudas AM, Jiménez A, Sureda FX, Rimbau V, Pubill D, Escubedo E, Camarasa J, Pallàs M, Camins A. 3-Amino thioacridone, a selective cyclin-dependent kinase 4 inhibitor, attenuates kainic acid-induced apoptosis in neurons. Neuroscience 2003; 120:599-603. [PMID: 12895500 DOI: 10.1016/s0306-4522(03)00424-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The mechanisms underlying selective neuronal cell death in kainic acid-mediated neurodegeneration are not fully understood. We have recently demonstrated that in cerebellar granule neurons, kainic acid induces the expression of proteins associated with cell-cycle progression. In the present study we show that 3-amino thioacridone (3-ATA), a selective cyclin-dependent kinase 4 inhibitor, attenuates kainic acid-induced apoptosis in cerebellar granule neurons. When neurons were pre-treated with 3-ATA 10 microM for 24 h, they were less susceptible to damage induced by kainic acid 500 microM, since the number of dead cells decreased significantly. In flow cytometry studies using propidium iodide staining, 3-ATA also reduced the ratio of apoptotic cells induced by kainic acid. Moreover, 3-ATA decreased the proportion of cells with a condensed nucleus from 55% to 22%. Our data suggest that the cell cycle pathway is involved in the mechanism of apoptosis mediated by kainic acid and that cyclin-dependent kinase 4 plays a prominent role in this process. 3-ATA may to prevent the apoptosis associated with neurodegenerative disorders without the over-activation of excitatory amino acid receptors.
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Affiliation(s)
- E Verdaguer
- Unitat de Farmacologia i Farmacognòsia, Facultat de Farmàcia, Universitat de Barcelona, Nucli Universitari de Pedralbes, E-08028 Barcelona, Spain
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23
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Verdaguer E, Jiménez A, Canudas AM, Jordà EG, Sureda FX, Pallàs M, Camins A. Inhibition of Cell Cycle Pathway by Flavopiridol Promotes Survival of Cerebellar Granule Cells after an Excitotoxic Treatment. J Pharmacol Exp Ther 2003; 308:609-16. [PMID: 14610234 DOI: 10.1124/jpet.103.057497] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Kainic acid (KA)-induced neuronal damage and the protective effects of flavopiridol were studied in primary cultures of rat cerebellar granule cells (CGNs). When neurons were treated with 500 microM KA, the percentage of cells with condensed nuclei measured by nuclear counting increased by up to 55%. After flavopiridol treatment, an antitumoral drug that is a broad inhibitor of cyclin-dependent kinases, the percentage of condensed nuclei decreased by up to 26%. Furthermore, this KA-mediated cell death was only partially dependent on the activation of the initiator caspase-9 and the effector caspases-3 and -6. This argues for a minor role of caspases in the intracellular pathway leading to KA-induced programmed cell death in CGNs. We examined the possible implication of cell cycle proteins in KA-induced neurotoxicity. We found an increase in the expression of proliferating cell nuclear antigen and E2F-1, two proteins implicated in S-phase, by Western blot. KA increased bromodeoxyuridine incorporation in CGNs, a marker of cell proliferation, and flavopiridol attenuated this effect. These results indicated that flavopiridol decreased the expression of cell cycle markers in CGNs after KA treatment. Flavopiridol might thus be used as a preventive agent against neurodegenerative diseases associated with cell cycle activation.
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Affiliation(s)
- Ester Verdaguer
- Unitat de Farmacologia i Farmacognòsia, Facultat de Farmàcia, Universitat de Barcelona, Nucli Universitari de Pedralbes, Barcelona, Spain.
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24
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Smith RA, Walker T, Xie X, Hou ST. Involvement of the transcription factor E2F1/Rb in kainic acid-induced death of murine cerebellar granule cells. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2003; 116:70-9. [PMID: 12941462 DOI: 10.1016/s0169-328x(03)00253-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The full mechanisms underlying neuronal death following excitotoxic insult remain unclear, despite many in vivo and in vitro studies. Recent work has focused on various signaling molecules and pathways, normally strictly regulated, that can trigger death if perturbed. The transcription factor, E2F1 is pivotal in controlling cell death under stress situations. The current study aimed to investigate the role of this transcription factor in modulating neuronal death following kainic acid (KA) treatment of cultured mouse cerebellar granule cells (CGCs). KA-induced death of CGCs was attenuated by the selective KA/AMPA receptor antagonist CNQX, but not MK-801. Such neuronal death was caspase-3-independent and did not activate many known death genes, such as Fas receptor, caspase-8 and p38. However, hyperphosphorylation of Rb showed a transient increase which may lead to activation of E2F1. Indeed E2F1 +/+ and -/- CGCs showed a differential response to KA-mediated toxicity, in that E2F1 -/- neurons were significantly less susceptible to KA compared to E2F1 +/+ neurons, albeit both E2F1 +/+ and -/- neurons expressed similar levels of KA receptors and responded similarly to kainate antagonist, CNQX. Using selective inhibitors to CDKs, such as olomoucine, roscovitine and flavopiridol, and the inhibitor SB203580 to p38 MAPK, we ruled out the possibility that Rb inactivation through hyperphosphorylation was due to either upstream kinases. Therefore activation of Rb/E2F1 pathway appears to involve novel interactions yet to be elucidated.
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Affiliation(s)
- Robert A Smith
- Experimental Stroke Group, NRC Institute for Biological Sciences, National Research Council of Canada, Building M54, 1500 Montreal Road, Ottawa, ON K1A 0R6, Canada.
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25
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Khan MZ, Brandimarti R, Musser BJ, Resue DM, Fatatis A, Meucci O. The chemokine receptor CXCR4 regulates cell-cycle proteins in neurons. J Neurovirol 2003; 9:300-14. [PMID: 12775414 PMCID: PMC2669737 DOI: 10.1080/13550280390201010] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Neurons express a variety of chemokine receptors that regulate neuronal signaling and survival, including CXCR4 and CCR5, the two major human immunodeficiency virus (HIV) coreceptors. However, the role of chemokine receptors in HIV neuropathology and neuroinflammatory disorders is still unclear. This study aims to determine whether chemokine receptors regulate the activity of cell-cycle proteins in neurons and evaluate the possibility that alterations of these proteins are involved in HIV neuropathogenesis. The authors studied the effect of the chemokine stromal cell-derived factor (SDF)-1alpha, the natural CXCR4 ligand, and an X4-using variant of gp120 on the activity of cell-cycle proteins involved in neuronal apoptosis and differentiation, such as Rb and E2F-1. Changes in expression, localization, and phosphorylation/activation of Rb and E2F-1 induced by SDF-1alpha (20 nM) gp120(IIIB) (200 pM) were analyzed in primary cultures of rat neurons and in a human cell line expressing recombinant CXCR4. The data indicate that changes in the nuclear and cytosolic levels of Rb--which result in the functional loss of this protein--are associated with apoptosis in hippocampal or cerebellar granule neurons and in cell lines. SDF-1alpha, which is able to rescue these neurons from apoptosis, induces a time-dependent increase of total Rb expression while decreasing the nuclear content of phosphorylated (Ser780/Ser795) Rb and the transcriptional activity of E2F-1. The HIV envelope protein gp120(IIIB) exerts opposite effects at the nuclear level. These data indicate that CXCR4 affects cell-cycle proteins in neurons and raise the possibility that chemokines may contribute to neuronal survival by repressing the activity of E2F-dependent apoptotic genes and maintaining neurons in a highly differentiated and quiescent state. This state may be altered during neuroinflammatory conditions and/or by HIV-derived proteins.
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Affiliation(s)
- Muhammad Zafrullah Khan
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Renato Brandimarti
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
- Department of Experimental Pathology, University of Bologna, Italy
| | - Brian Joseph Musser
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Danielle Marie Resue
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Alessandro Fatatis
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Olimpia Meucci
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
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26
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Ranganathan S, Bowser R. Alterations in G(1) to S phase cell-cycle regulators during amyotrophic lateral sclerosis. THE AMERICAN JOURNAL OF PATHOLOGY 2003; 162:823-35. [PMID: 12598317 PMCID: PMC1868100 DOI: 10.1016/s0002-9440(10)63879-5] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/21/2002] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is characterized by progressive degeneration of the motor neurons in the cerebral cortex, brain stem, and spinal cord. However, the mechanisms that regulate the initiation and/or progression of motor neuron loss in this disease remain enigmatic. Cell-cycle proteins and transcriptional regulators such as cyclins, cyclin-associated kinases, the retinoblastoma gene product (pRb), and E2F-1 function during cellular proliferation, differentiation, and cell death pathways. Recent data has implicated increased expression and activation of various cell-cycle proteins in neuronal cell death. We have examined the expression and subcellular distribution of G(1) to S phase cell-cycle regulators in the spinal cord, motor cortex, and sensory cortex from clinically and neuropathologically diagnosed sporadic ALS cases and age-matched controls. Our results indicate hyperphosphorylation of the retinoblastoma protein in motor neurons during ALS, concurrent with increased levels of cyclin D, and redistribution of E2F-1 into the cytoplasm of motor neurons and glia. These data suggest that G(1) to S phase activation occurs during ALS and may participate in molecular mechanisms regulating motor neuron death.
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Affiliation(s)
- Srikanth Ranganathan
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
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Boutillier AL, Trinh E, Loeffler JP. Selective E2F-dependent gene transcription is controlled by histone deacetylase activity during neuronal apoptosis. J Neurochem 2003; 84:814-28. [PMID: 12562525 DOI: 10.1046/j.1471-4159.2003.01581.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The alteration of chromatin through histone acetylation and deacetylation participates in the regulation of gene expression. We have investigated the effects of histone deacetylase inhibition on neuronal fate. We show that treatment of primary neurones with trichostatin A (TSA) or sodium butyrate (NaBu) induces typical features of apoptosis, a cell death that relies on specific genetic programmes. We have further explored the molecular mechanisms implicated in the TSA response and demonstrated that TSA-induced apoptosis is partly dependent on the activation of the transcription factor E2F-1, which has pro-apoptotic functions in these neurones. Furthermore, the increased e2f-1 transcriptional response is probably the result of mechanisms occurring through E2F-responsive elements. Histone acetylation also takes place at the e2f-1 promoter, but this modification is neither required nor by itself sufficient to induce increased transcription at the e2f-1 promoter. Activation might thus occur through acetylation of non-histone proteins binding this regulatory element. Finally, we show that TSA induces the transcription of E2F-dependent genes, such as its cell cycle target cyclin E, but also pro-apoptotic genes, such as Apaf1. Taken together, our results suggest that, in neuroprotective conditions, histone deacetylase activity allows a constitutive repression of the e2f-1 gene in mature neurones in order to ensure survival. Deregulation of this repression will ultimately lead to an E2F-dependent cell death.
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Affiliation(s)
- Anne-Laurence Boutillier
- Laboratoire de Signalisations Moléculaires et Neurodégénérescence, EA no. 3433, 11 rue Humann, 67085 Strasbourg cedex, France.
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Boutillier AL, Trinh E, Loeffler JP. Constitutive repression of E2F1 transcriptional activity through HDAC proteins is essential for neuronal survival. Ann N Y Acad Sci 2002; 973:438-42. [PMID: 12485907 DOI: 10.1111/j.1749-6632.2002.tb04679.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Anne-Laurence Boutillier
- Laboratoire de Signalisations Moléculaires et Neurodégénérescence EA 3433, Faculté de Médecine, 67085 Strasbourg Cedex, France.
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Zhu Y, Mao XO, Sun Y, Xia Z, Greenberg DA. p38 Mitogen-activated protein kinase mediates hypoxic regulation of Mdm2 and p53 in neurons. J Biol Chem 2002; 277:22909-14. [PMID: 11948180 DOI: 10.1074/jbc.m200042200] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The multifunctional tumor suppressor protein, p53, inhibits cell growth and promotes differentiation and programmed cell death. p53 activity is controlled by transcriptional, translational, and post-translational regulation. A major pathway for post-translational regulation of p53 comprises its nucleocytoplasmic transport and subsequent proteasomal degradation, which involves binding to the oncoprotein, murine double minute-2 (Mdm2). Hypoxia and other stress signals cause cellular injury partly through the action of p53. In this study, we show that hypoxia induces down-regulation of Mdm2 as well as serine 15 phosphorylation and nuclear accumulation of p53 in cultured cortical neurons from E16 mice. These effects are diminished by the p38 mitogen-activated protein kinase inhibitors SB203580 and SB202190, but not by the inactive analog SB202474, and by a dominant-interfering mutant of the p38-activating kinase mitogen-activated protein kinase kinase 3 (MKK3). Hypoxic neuronal death was also reduced by p38 inhibitors, by dominant-interfering MKK3, and by a p53-antisense oligodeoxynucleotide and was increased by a constitutively active form of p38 and by an Mdm2-antisense oligodeoxynucleotide. These results demonstrate that p38 and Mdm2 have roles in coupling hypoxic-ischemic neuronal insults to activation of p53 and hypoxic cell death.
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Affiliation(s)
- Yonghua Zhu
- Buck Institute for Age Research, Novato, California 94945, USA
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Hou ST, Cowan E, Dostanic S, Rasquinha I, Comas T, Morley P, MacManus JP. Increased expression of the transcription factor E2F1 during dopamine-evoked, caspase-3-mediated apoptosis in rat cortical neurons. Neurosci Lett 2001; 306:153-6. [PMID: 11406318 DOI: 10.1016/s0304-3940(01)01909-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The transcription factor E2F1 mRNA and protein levels increased in rat cortical neurons in response to dopamine (DA)- or 6-hydroxydopamine (OHDA)-evoked apoptosis. Increased E2F1 protein was detected in the nucleus of neurons by double fluorescent immunocytochemistry using antibodies to E2F1 and NeuN. DA and 6-OHDA induced caspase-3-mediated apoptosis of cortical neurons which was attenuated by the addition of antioxidants or caspase-3 inhibitors to the cultures. Antioxidants prevented DA-evoked neuronal apoptosis, and also attenuated the increase in E2F1 expression. These findings suggest that increased expression of the transcription factor E2F1 may serve as a death signal during DA-evoked neuronal apoptosis.
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Affiliation(s)
- S T Hou
- Institute for Biological Sciences, National Research Council Canada, Building M-54, 1500 Montreal Road, Ottawa, Ontario, K1A 0R6, Canada.
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