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Gao S, Huang S, Xu Y, Wang B, Cheng P, Lu Y, Gilson E, Ye J. Role of the telomeric factor TRF2 in post-hypoxic brain damages. Redox Biol 2024; 75:103278. [PMID: 39128227 DOI: 10.1016/j.redox.2024.103278] [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: 06/22/2024] [Accepted: 07/20/2024] [Indexed: 08/13/2024] Open
Abstract
The neuronal excitotoxicity that follows reoxygenation after a hypoxic period may contribute to epilepsy, Alzheimer's disease, Parkinson's disease and various disorders that are related to inadequate supplement of oxygen in neurons. Therefore, counteracting the deleterious effects of post-hypoxic stress is an interesting strategy to treat a large spectrum of neurodegenerative diseases. Here, we show that the expression of the key telomere protecting protein Trf2 decreases in the brain of mice submitted to a post-hypoxic stress. Moreover, downregulating the expression of Terf2 in hippocampal neural cells of unchallenged mice triggers an excitotoxicity-like phenotype including glutamate overexpression and behavioral alterations while overexpressing Terf2 in hippocampal neural cells of mice subjected to a post-hypoxic treatment prevents brain damages. Moreover, Terf2 overexpression in culture neurons counteracts the oxidative stress triggered by glutamate. Finally, we provide evidence that the effect of Terf2 downregulation on excitotoxicity involves Sirt3 repression leading to mitochondrial dysfunction. We propose that increasing the level of Terf2 expression is a potential strategy to reduce post-hypoxic stress damages.
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Affiliation(s)
- Shuaiyun Gao
- Department of Geriatrics, Medical Center on Aging of Shanghai Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Pôle Sino-Français de Recherches en Sciences du Vivant et Génomique, International Research Project Cancer, Aging and Hematology, RuiJin Hospital, Shanghai Jiao Tong University School of Medicine/CNRS/INSERM/University Côte d'Azur, Shanghai, China; The State Key Laboratory of Medical Genomics, Shanghai, 200025, China
| | - Sheng Huang
- Department of Geriatrics, Medical Center on Aging of Shanghai Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Pôle Sino-Français de Recherches en Sciences du Vivant et Génomique, International Research Project Cancer, Aging and Hematology, RuiJin Hospital, Shanghai Jiao Tong University School of Medicine/CNRS/INSERM/University Côte d'Azur, Shanghai, China; The State Key Laboratory of Medical Genomics, Shanghai, 200025, China
| | - Yiwen Xu
- Department of Geriatrics, Medical Center on Aging of Shanghai Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Pôle Sino-Français de Recherches en Sciences du Vivant et Génomique, International Research Project Cancer, Aging and Hematology, RuiJin Hospital, Shanghai Jiao Tong University School of Medicine/CNRS/INSERM/University Côte d'Azur, Shanghai, China; The State Key Laboratory of Medical Genomics, Shanghai, 200025, China
| | - Bo Wang
- Department of Geriatrics, Medical Center on Aging of Shanghai Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Pôle Sino-Français de Recherches en Sciences du Vivant et Génomique, International Research Project Cancer, Aging and Hematology, RuiJin Hospital, Shanghai Jiao Tong University School of Medicine/CNRS/INSERM/University Côte d'Azur, Shanghai, China; The State Key Laboratory of Medical Genomics, Shanghai, 200025, China
| | - Peng Cheng
- Department of Geriatrics, Medical Center on Aging of Shanghai Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Pôle Sino-Français de Recherches en Sciences du Vivant et Génomique, International Research Project Cancer, Aging and Hematology, RuiJin Hospital, Shanghai Jiao Tong University School of Medicine/CNRS/INSERM/University Côte d'Azur, Shanghai, China; The State Key Laboratory of Medical Genomics, Shanghai, 200025, China
| | - Yiming Lu
- Department of Geriatrics, Medical Center on Aging of Shanghai Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Pôle Sino-Français de Recherches en Sciences du Vivant et Génomique, International Research Project Cancer, Aging and Hematology, RuiJin Hospital, Shanghai Jiao Tong University School of Medicine/CNRS/INSERM/University Côte d'Azur, Shanghai, China; The State Key Laboratory of Medical Genomics, Shanghai, 200025, China; Department of Emergency, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
| | - Eric Gilson
- Pôle Sino-Français de Recherches en Sciences du Vivant et Génomique, International Research Project Cancer, Aging and Hematology, RuiJin Hospital, Shanghai Jiao Tong University School of Medicine/CNRS/INSERM/University Côte d'Azur, Shanghai, China; University Côte d'Azur, Inserm, CNRS, IRCAN, Nice, France; Department of Medical Genetics, IHU RespirERA, CHU, Nice, France.
| | - Jing Ye
- Department of Geriatrics, Medical Center on Aging of Shanghai Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Pôle Sino-Français de Recherches en Sciences du Vivant et Génomique, International Research Project Cancer, Aging and Hematology, RuiJin Hospital, Shanghai Jiao Tong University School of Medicine/CNRS/INSERM/University Côte d'Azur, Shanghai, China; The State Key Laboratory of Medical Genomics, Shanghai, 200025, China; Department of Emergency, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
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Deshpande K, Martirosian V, Nakamura BN, Das D, Iyer M, Reed M, Shao L, Bamshad D, Buckley NJ, Neman J. SRRM4-mediated REST to REST4 dysregulation promotes tumor growth and neural adaptation in breast cancer leading to brain metastasis. Neuro Oncol 2024; 26:309-322. [PMID: 37716001 PMCID: PMC10836770 DOI: 10.1093/neuonc/noad175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Indexed: 09/18/2023] Open
Abstract
BACKGROUND Effective control of brain metastasis remains an urgent clinical need due a limited understanding of the mechanisms driving it. Although the gain of neuro-adaptive attributes in breast-to-brain metastases (BBMs) has been described, the mechanisms that govern this neural acclimation and the resulting brain metastasis competency are poorly understood. Herein, we define the role of neural-specific splicing factor Serine/Arginine Repetitive Matrix Protein 4 (SRRM4) in regulating microenvironmental adaptation and brain metastasis colonization in breast cancer cells. METHODS Utilizing pure neuronal cultures and brain-naive and patient-derived BM tumor cells, along with in vivo tumor modeling, we surveyed the early induction of mediators of neural acclimation in tumor cells. RESULTS When SRRM4 is overexpressed in systemic breast cancer cells, there is enhanced BBM leading to poorer overall survival in vivo. Concomitantly, SRRM4 knockdown expression does not provide any advantage in central nervous system metastasis. In addition, reducing SRRM4 expression in breast cancer cells slows down proliferation and increases resistance to chemotherapy. Conversely, when SRRM4/REST4 levels are elevated, tumor cell growth is maintained even in nutrient-deprived conditions. In neuronal coculture, decreasing SRRM4 expression in breast cancer cells impairs their ability to adapt to the brain microenvironment, while increasing SRRM4/RE-1 Silencing Transcription Factor (REST4) levels leads to greater expression of neurotransmitter and synaptic signaling mediators and a significant colonization advantage. CONCLUSIONS Collectively, our findings identify SRRM4 as a regulator of brain metastasis colonization, and a potential therapeutic target in breast cancer.
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Affiliation(s)
- Krutika Deshpande
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- USC Brain Tumor Center, Keck School of Medicine, University of Southern California, Los Angeles, California, USA)
| | - Vahan Martirosian
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- USC Brain Tumor Center, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Brooke N Nakamura
- Division of Gastrointestinal and Liver Diseases, Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- USC Brain Tumor Center, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Diganta Das
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- USC Brain Tumor Center, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Mukund Iyer
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- USC Brain Tumor Center, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Max Reed
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Ling Shao
- Division of Gastrointestinal and Liver Diseases, Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Daniella Bamshad
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Noel J Buckley
- Department of Psychiatry, University of Oxford, Oxford, UK
| | - Josh Neman
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- USC Brain Tumor Center, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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Wolf SE, Shalev I. The shelterin protein expansion of telomere dynamics: Linking early life adversity, life history, and the hallmarks of aging. Neurosci Biobehav Rev 2023; 152:105261. [PMID: 37268182 PMCID: PMC10527177 DOI: 10.1016/j.neubiorev.2023.105261] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 04/10/2023] [Accepted: 05/30/2023] [Indexed: 06/04/2023]
Abstract
Aging is characterized by functional decline occurring alongside changes to several hallmarks of aging. One of the hallmarks includes attrition of repeated DNA sequences found at the ends of chromosomes called telomeres. While telomere attrition is linked to morbidity and mortality, whether and how it causally contributes to lifelong rates of functional decline is unclear. In this review, we propose the shelterin-telomere hypothesis of life history, in which telomere-binding shelterin proteins translate telomere attrition into a range of physiological outcomes, the extent of which may be modulated by currently understudied variation in shelterin protein levels. Shelterin proteins may expand the breadth and timing of consequences of telomere attrition, e.g., by translating early life adversity into acceleration of the aging process. We consider how the pleiotropic roles of shelterin proteins provide novel insights into natural variation in physiology, life history, and lifespan. We highlight key open questions that encourage the integrative, organismal study of shelterin proteins that enhances our understanding of the contribution of the telomere system to aging.
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Affiliation(s)
- Sarah E Wolf
- Department of Biobehavioral Health, Penn State University, University Park, PA 16802, USA.
| | - Idan Shalev
- Department of Biobehavioral Health, Penn State University, University Park, PA 16802, USA
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Yamato E. Aberrant Expression of Rest4 Gene in Low-Functioning Pancreatic Beta Cell Line. Horm Metab Res 2023. [PMID: 36758614 DOI: 10.1055/a-2031-9803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Repressor element-1 silencing transcription factor (Rest) is not expressed in pancreatic beta cells and neuronal cells. However, Rest4, a truncated form of Rest, is expressed in high passaged MIN6 (HP-MIN6) cells, a pancreatic beta cell line that lost glucose-responsive insulin secretion. Rest4 is also expressed in injured MIN6 cells and isolated islets. Herein, the forced expression of dominant negative form of Rest in HP-MIN6 cells was subjected to microarray analysis of gene expression to investigate the role of Rest4 gene in MIN6 cells. Furthermore, the forced expression of Rest4 gene in MIN6 cells was subjected to microarray analysis of gene expression to investigate the function of Rest4 in normal insulin-producing cells. The results showed that Rest4 inhibits cell proliferation and DNA and RNA metabolism and stimulates secretory mechanisms and nervous system gene expression. These findings suggest that Rest4 may act defensively against cellular injury in pancreatic beta cells.
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Affiliation(s)
- Eiji Yamato
- Nutrition and Food Science, Mukogawa Woman's University, Nishinomiya, Japan
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5
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Vinayagamurthy S, Bagri S, Mergny JL, Chowdhury S. Telomeres expand sphere of influence: emerging molecular impact of telomeres in non-telomeric functions. Trends Genet 2023; 39:59-73. [PMID: 36404192 PMCID: PMC7614491 DOI: 10.1016/j.tig.2022.10.002] [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: 06/05/2022] [Revised: 09/12/2022] [Accepted: 10/26/2022] [Indexed: 11/18/2022]
Abstract
Although the impact of telomeres on physiology stands well established, a question remains: how do telomeres impact cellular functions at a molecular level? This is because current understanding limits the influence of telomeres to adjacent subtelomeric regions despite the wide-ranging impact of telomeres. Emerging work in two distinct aspects offers opportunities to bridge this gap. First, telomere-binding factors were found with non-telomeric functions. Second, locally induced DNA secondary structures called G-quadruplexes are notably abundant in telomeres, and gene regulatory regions genome wide. Many telomeric factors bind to G-quadruplexes for non-telomeric functions. Here we discuss a more general model of how telomeres impact the non-telomeric genome - through factors that associate at telomeres and genome wide - and influence cell-intrinsic functions, particularly aging, cancer, and pluripotency.
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Affiliation(s)
- Soujanya Vinayagamurthy
- Integrative and Functional Biology Unit, CSIR Institute of Genomics and Integrative Biology, New Delhi 110025, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Sulochana Bagri
- Integrative and Functional Biology Unit, CSIR Institute of Genomics and Integrative Biology, New Delhi 110025, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Jean-Louis Mergny
- Institute of Biophysics of the CAS, v.v.i. Královopolská 135, 612 65 Brno, Czech Republic; Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Shantanu Chowdhury
- Integrative and Functional Biology Unit, CSIR Institute of Genomics and Integrative Biology, New Delhi 110025, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India; GNR Knowledge Centre for Genome and Informatics, CSIR Institute of Genomics and Integrative Biology, New Delhi 110025, India.
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6
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Yu EY, Cheung NKV, Lue NF. Connecting telomere maintenance and regulation to the developmental origin and differentiation states of neuroblastoma tumor cells. J Hematol Oncol 2022; 15:117. [PMID: 36030273 PMCID: PMC9420296 DOI: 10.1186/s13045-022-01337-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 07/28/2022] [Indexed: 11/18/2022] Open
Abstract
A cardinal feature that distinguishes clinically high-risk neuroblastoma from low-risk tumors is telomere maintenance. Specifically, neuroblastoma tumors with either active telomerase or alternative lengthening of telomeres exhibit aggressive growth characteristics that lead to poor outcomes, whereas tumors without telomere maintenance can be managed with observation or minimal treatment. Even though the need for cancer cells to maintain telomere DNA-in order to sustain cell proliferation-is well established, recent studies suggest that the neural crest origin of neuroblastoma may enforce unique relationships between telomeres and tumor malignancy. Specifically in neuroblastoma, telomere structure and telomerase activity are correlated with the adrenergic/mesenchymal differentiation states, and manipulating telomerase activity can trigger tumor cell differentiation. Both findings may reflect features of normal neural crest development. This review summarizes recent advances in the characterization of telomere structure and telomere maintenance mechanisms in neuroblastoma and discusses the findings in the context of relevant literature on telomeres during embryonic and neural development. Understanding the canonical and non-canonical roles of telomere maintenance in neuroblastoma could reveal vulnerabilities for telomere-directed therapies with potential applications to other pediatric malignancies.
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Affiliation(s)
- Eun Young Yu
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - Nai-Kong V Cheung
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA
| | - Neal F Lue
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA.
- Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA.
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7
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Ying Y, Hu X, Han P, Mendez-Bermudez A, Bauwens S, Eid R, Tan L, Pousse M, Giraud-Panis MJ, Lu Y, Gilson E, Ye J. OUP accepted manuscript. Nucleic Acids Res 2022; 50:2081-2095. [PMID: 35150283 PMCID: PMC8887477 DOI: 10.1093/nar/gkac065] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 12/22/2021] [Accepted: 02/05/2022] [Indexed: 11/18/2022] Open
Abstract
The shelterin protein complex is required for telomere protection in various eukaryotic organisms. In mammals, the shelterin subunit TRF2 is specialized in preventing ATM activation at telomeres and chromosome end fusion in somatic cells. Here, we demonstrate that the zebrafish ortholog of TRF2 (encoded by the terfa gene) is protecting against unwanted ATM activation genome-wide. The terfa-compromised fish develop a prominent and specific embryonic neurodevelopmental failure. The heterozygous fish survive to adulthood but exhibit a premature aging phenotype. The recovery from embryonic neurodevelopmental failure requires both ATM inhibition and transcriptional complementation of neural genes. Furthermore, restoring the expression of TRF2 in glial cells rescues the embryonic neurodevelopment phenotype. These results indicate that the shelterin subunit TRF2 evolved in zebrafish as a general factor of genome maintenance and transcriptional regulation that is required for proper neurodevelopment and normal aging. These findings uncover how TRF2 links development to aging by separate functions in gene expression regulation and genome stability control.
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Affiliation(s)
| | | | | | - Aaron Mendez-Bermudez
- Department of Geriatrics, Medical center on Aging of Shanghai Ruijin Hospital, Shanghai Jiaotong University school of Medicine; International Laboratory in Hematology and Cancer, Shanghai Jiao Tong University School of Medicine/Ruijin Hospital/CNRS/Inserm/Côte d’Azur University, PR China
- Côte d’Azur University, CNRS, INSERM, IRCAN, Faculty of Medicine Nice, France
| | - Serge Bauwens
- Côte d’Azur University, CNRS, INSERM, IRCAN, Faculty of Medicine Nice, France
| | - Rita Eid
- Côte d’Azur University, CNRS, INSERM, IRCAN, Faculty of Medicine Nice, France
| | - Li Tan
- Shanghai Center for Plant Stress Center, CAS Center for Excellence in Molecular Plant Sciences, PR China
| | - Mélanie Pousse
- Côte d’Azur University, CNRS, INSERM, IRCAN, Faculty of Medicine Nice, France
| | | | - Yiming Lu
- Department of Geriatrics, Medical center on Aging of Shanghai Ruijin Hospital, Shanghai Jiaotong University school of Medicine; International Laboratory in Hematology and Cancer, Shanghai Jiao Tong University School of Medicine/Ruijin Hospital/CNRS/Inserm/Côte d’Azur University, PR China
- The State Key Laboratory of Medical Genomics, Pôle Sino-Français de Recherche en Sciences Du Vivant et Génomique, China
| | - Eric Gilson
- Correspondence may also be addressed to Eric Gilson. Tel: +33 04 93 95 77 07; Fax: +33 04 93 95 77 08;
| | - Jing Ye
- To whom correspondence should be addressed. Tel: +86 6437 0045 61 1110; Fax: +86 6437 0045 61 1105;
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8
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Yu EY, Zahid SS, Aloe S, Falck-Pedersen E, Zhou XK, Cheung NKV, Lue NF. Reciprocal impacts of telomerase activity and ADRN/MES differentiation state in neuroblastoma tumor biology. Commun Biol 2021; 4:1315. [PMID: 34799676 PMCID: PMC8604896 DOI: 10.1038/s42003-021-02821-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 10/29/2021] [Indexed: 01/01/2023] Open
Abstract
Telomere maintenance and tumor cell differentiation have been separately implicated in neuroblastoma malignancy. Their mechanistic connection is unclear. We analyzed neuroblastoma cell lines and morphologic subclones representing the adrenergic (ADRN) and mesenchymal (MES) differentiation states and uncovered sharp differences in their telomere protein and telomerase activity levels. Pharmacologic conversion of ADRN into MES cells elicited consistent and robust changes in the expression of telomere-related proteins. Conversely, stringent down-regulation of telomerase activity triggers the differentiation of ADRN into MES cells, which was reversible upon telomerase up-regulation. Interestingly, the MES differentiation state is associated with elevated levels of innate immunity factors, including key components of the DNA-sensing pathway. Accordingly, MES but not ADRN cells can mount a robust response to viral infections in vitro. A gene expression signature based on telomere and cell lineage-related factors can cluster neuroblastoma tumor samples into predominantly ADRN or MES-like groups, with distinct clinical outcomes. Our findings establish a strong mechanistic connection between telomere and differentiation and suggest that manipulating telomeres may suppress malignancy not only by limiting the tumor growth potential but also by inducing tumor cell differentiation and altering its immunogenicity.
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Affiliation(s)
- Eun Young Yu
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, New York, NY, USA
| | - Syed S Zahid
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, New York, NY, USA
| | - Sarah Aloe
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, New York, NY, USA
| | - Erik Falck-Pedersen
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, New York, NY, USA
| | - Xi Kathy Zhou
- Department of Population Health Sciences, Weill Cornell Medicine, New York, NY, USA
| | - Nai-Kong V Cheung
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Neal F Lue
- Department of Microbiology & Immunology, W. R. Hearst Microbiology Research Center, Weill Cornell Medicine, New York, NY, USA.
- Sandra and Edward Meyer Cancer Center, Weill Cornell Medical College, New York, NY, USA.
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9
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Imran SAM, Yazid MD, Cui W, Lokanathan Y. The Intra- and Extra-Telomeric Role of TRF2 in the DNA Damage Response. Int J Mol Sci 2021; 22:ijms22189900. [PMID: 34576063 PMCID: PMC8470803 DOI: 10.3390/ijms22189900] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/06/2021] [Accepted: 09/09/2021] [Indexed: 12/12/2022] Open
Abstract
Telomere repeat binding factor 2 (TRF2) has a well-known function at the telomeres, which acts to protect the telomere end from being recognized as a DNA break or from unwanted recombination. This protection mechanism prevents DNA instability from mutation and subsequent severe diseases caused by the changes in DNA, such as cancer. Since TRF2 actively inhibits the DNA damage response factors from recognizing the telomere end as a DNA break, many more studies have also shown its interactions outside of the telomeres. However, very little has been discovered on the mechanisms involved in these interactions. This review aims to discuss the known function of TRF2 and its interaction with the DNA damage response (DDR) factors at both telomeric and non-telomeric regions. In this review, we will summarize recent progress and findings on the interactions between TRF2 and DDR factors at telomeres and outside of telomeres.
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Affiliation(s)
- Siti A. M. Imran
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.)
| | - Muhammad Dain Yazid
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.)
| | - Wei Cui
- Institute of Reproductive and Developmental Biology, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK;
| | - Yogeswaran Lokanathan
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.)
- Correspondence: ; Tel.: +603-9145-7704
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Imran SAM, Yazid MD, Idrus RBH, Maarof M, Nordin A, Razali RA, Lokanathan Y. Is There an Interconnection between Epithelial-Mesenchymal Transition (EMT) and Telomere Shortening in Aging? Int J Mol Sci 2021; 22:ijms22083888. [PMID: 33918710 PMCID: PMC8070110 DOI: 10.3390/ijms22083888] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 04/07/2021] [Accepted: 04/07/2021] [Indexed: 12/12/2022] Open
Abstract
Epithelial–Mesenchymal Transition (EMT) was first discovered during the transition of cells from the primitive streak during embryogenesis in chicks. It was later discovered that EMT holds greater potential in areas other than the early development of cells and tissues since it also plays a vital role in wound healing and cancer development. EMT can be classified into three types based on physiological functions. EMT type 3, which involves neoplastic development and metastasis, has been the most thoroughly explored. As EMT is often found in cancer stem cells, most research has focused on its association with other factors involving cancer progression, including telomeres. However, as telomeres are also mainly involved in aging, any possible interaction between the two would be worth noting, especially as telomere dysfunction also contributes to cancer and other age-related diseases. Ascertaining the balance between degeneration and cancer development is crucial in cell biology, in which telomeres function as a key regulator between the two extremes. The essential roles that EMT and telomere protection have in aging reveal a potential mutual interaction that has not yet been explored, and which could be used in disease therapy. In this review, the known functions of EMT and telomeres in aging are discussed and their potential interaction in age-related diseases is highlighted.
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Affiliation(s)
- Siti A. M. Imran
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.); (R.B.H.I.); (M.M.); (A.N.); (R.A.R.)
| | - Muhammad Dain Yazid
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.); (R.B.H.I.); (M.M.); (A.N.); (R.A.R.)
| | - Ruszymah Bt Hj Idrus
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.); (R.B.H.I.); (M.M.); (A.N.); (R.A.R.)
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia
| | - Manira Maarof
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.); (R.B.H.I.); (M.M.); (A.N.); (R.A.R.)
| | - Abid Nordin
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.); (R.B.H.I.); (M.M.); (A.N.); (R.A.R.)
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia
| | - Rabiatul Adawiyah Razali
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.); (R.B.H.I.); (M.M.); (A.N.); (R.A.R.)
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia
| | - Yogeswaran Lokanathan
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur 56000, Malaysia; (S.A.M.I.); (M.D.Y.); (R.B.H.I.); (M.M.); (A.N.); (R.A.R.)
- Correspondence: ; Tel.: +60-391457704
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11
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Vinayagamurthy S, Ganguly A, Chowdhury S. Extra-telomeric impact of telomeres: Emerging molecular connections in pluripotency or stemness. J Biol Chem 2020; 295:10245-10254. [PMID: 32444498 PMCID: PMC7383370 DOI: 10.1074/jbc.rev119.009710] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 05/21/2020] [Indexed: 12/26/2022] Open
Abstract
Telomeres comprise specialized nucleic acid-protein complexes that help protect chromosome ends from DNA damage. Moreover, telomeres associate with subtelomeric regions through looping. This results in altered expression of subtelomeric genes. Recent observations further reveal telomere length-dependent gene regulation and epigenetic modifications at sites spread across the genome and distant from telomeres. This regulation is mediated through the telomere-binding protein telomeric repeat-binding factor 2 (TRF2). These observations suggest a role of telomeres in extra-telomeric functions. Most notably, telomeres have a broad impact on pluripotency and differentiation. For example, cardiomyocytes differentiate with higher efficacy from induced pluripotent stem cells having long telomeres, and differentiated cells obtained from human embryonic stem cells with relatively long telomeres have a longer lifespan. Here, we first highlight reports on these two seemingly distinct research areas: the extra-telomeric role of telomere-binding factors and the role of telomeres in pluripotency/stemness. On the basis of the observations reported in these studies, we draw attention to potential molecular connections between extra-telomeric biology and pluripotency. Finally, in the context of the nonlocal influence of telomeres on pluripotency and stemness, we discuss major opportunities for progress in molecular understanding of aging-related disorders and neurodegenerative diseases.
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Affiliation(s)
- Soujanya Vinayagamurthy
- Integrative and Functional Biology Unit, CSIR Institute of Genomics and Integrative Biology, New Delhi, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR Institute of Genomics and Integrative Biology, New Delhi, India
| | - Akansha Ganguly
- Integrative and Functional Biology Unit, CSIR Institute of Genomics and Integrative Biology, New Delhi, India
| | - Shantanu Chowdhury
- Integrative and Functional Biology Unit, CSIR Institute of Genomics and Integrative Biology, New Delhi, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR Institute of Genomics and Integrative Biology, New Delhi, India
- G.N.R. Knowledge Centre for Genome Informatics, CSIR Institute of Genomics and Integrative Biology, New Delhi, India
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12
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Wu S, Ge Y, Li X, Yang Y, Zhou H, Lin K, Zhang Z, Zhao Y. BRM-SWI/SNF chromatin remodeling complex enables functional telomeres by promoting co-expression of TRF2 and TRF1. PLoS Genet 2020; 16:e1008799. [PMID: 32502208 PMCID: PMC7299400 DOI: 10.1371/journal.pgen.1008799] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 06/17/2020] [Accepted: 04/26/2020] [Indexed: 12/20/2022] Open
Abstract
TRF2 and TRF1 are a key component in shelterin complex that associates with telomeric DNA and protects chromosome ends. BRM is a core ATPase subunit of SWI/SNF chromatin remodeling complex. Whether and how BRM-SWI/SNF complex is engaged in chromatin end protection by telomeres is unknown. Here, we report that depletion of BRM does not affect heterochromatin state of telomeres, but results in telomere dysfunctional phenomena including telomere uncapping and replication defect. Mechanistically, expression of TRF2 and TRF1 is jointly regulated by BRM-SWI/SNF complex, which is localized to promoter region of both genes and facilitates their transcription. BRM-deficient cells bear increased TRF2-free or TRF1-free telomeres due to insufficient expression. Importantly, BRM depletion-induced telomere uncapping or replication defect can be rescued by compensatory expression of exogenous TRF2 or TRF1, respectively. Together, these results identify a new function of BRM-SWI/SNF complex in enabling functional telomeres for maintaining genome stability. Human telomeres consist of repetitive “TTAGGG” DNA sequences and associated shelterin complex, which maintain genomic stability by preventing linear chromosome ends from being recognized as broken DNA. TRF1 and TRF2, as key components of shelterin complex, directly associate with double strand telomeric DNA. In this study, we discovered that both TRF1 and TRF2 are jointly regulated by BRM-SWI/SNF complex. Depletion of BRM led to insufficient amount of TRF1 and TRF2, which is associated with telomere replication defect and telomere uncapping. More importantly, these phenomena can be rescued by ectopically expressed TRF1 and TRF2. Our work demonstrates a specific role of BRM-SWI/SNF complex on safeguarding genome stability by enabling functional telomeres.
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Affiliation(s)
- Shu Wu
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yuanlong Ge
- Key Laboratory of Regenerative Medicine of Ministry of Education, Institute of Aging and Regenerative Medicine, Jinan University, Guangzhou, China
| | - Xiaocui Li
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yiding Yang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Haoxian Zhou
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Kaixuan Lin
- Yale Stem Cell Center & Department of Genetics, Yale School of Medicine, New Haven, Connecticut, United States of America
| | - Zepeng Zhang
- Key Laboratory of Regenerative Medicine of Ministry of Education, Institute of Aging and Regenerative Medicine, Jinan University, Guangzhou, China
| | - Yong Zhao
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- * E-mail:
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13
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Long-lived post-mitotic cell aging: is a telomere clock at play? Mech Ageing Dev 2020; 189:111256. [PMID: 32380018 DOI: 10.1016/j.mad.2020.111256] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/25/2020] [Accepted: 04/27/2020] [Indexed: 12/27/2022]
Abstract
Senescence is a cellular response to stress for both dividing and post-mitotic cells. Noteworthy, long-lived post-mitotic cells (collectively named LLPMCs), which can live for decades in the organism, can exhibit a distinct type of cellular aging characterized by a progressive functional decline not associated to an overt senescence phenotype. The age-related drivers of senescence and aging in LLPMCs remain largely unknown. There is evidence that an increased production of reactive oxygen species (ROS) due to dysfunctional mitochondria, coupled with an inherent inability of cellular-degradation mechanisms to remove damaged molecules, is responsible for senescence and aging in LLPMC. Although telomeric DNA shortening, by nature linked to cell division, is generally not considered as a driver of LLPMC aging and senescence, we discuss recent reports revealing the existence of age-related telomere changes in LLPMC. These findings reveal unexpected roles for telomeres in LLPMC function and invite us to consider the hypothesis of a complex telomere clock involved in both dividing and non-dividing cell aging.
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14
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Zizza P, Dinami R, Porru M, Cingolani C, Salvati E, Rizzo A, D'Angelo C, Petti E, Amoreo CA, Mottolese M, Sperduti I, Chambery A, Russo R, Ostano P, Chiorino G, Blandino G, Sacconi A, Cherfils-Vicini J, Leonetti C, Gilson E, Biroccio A. TRF2 positively regulates SULF2 expression increasing VEGF-A release and activity in tumor microenvironment. Nucleic Acids Res 2019; 47:3365-3382. [PMID: 30698737 PMCID: PMC6468246 DOI: 10.1093/nar/gkz041] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 01/16/2019] [Indexed: 12/04/2022] Open
Abstract
The telomeric protein TRF2 is overexpressed in several human malignancies and contributes to tumorigenesis even though the molecular mechanism is not completely understood. By using a high-throughput approach based on the multiplexed Luminex X-MAP technology, we demonstrated that TRF2 dramatically affects VEGF-A level in the secretome of cancer cells, promoting endothelial cell-differentiation and angiogenesis. The pro-angiogenic effect of TRF2 is independent from its role in telomere capping. Instead, TRF2 binding to a distal regulatory element promotes the expression of SULF2, an endoglucosamine-6-sulfatase that impairs the VEGF-A association to the plasma membrane by inducing post-synthetic modification of heparan sulfate proteoglycans (HSPGs). Finally, we addressed the clinical relevance of our findings showing that TRF2/SULF2 expression is a worse prognostic biomarker in colorectal cancer (CRC) patients.
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Affiliation(s)
- Pasquale Zizza
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Roberto Dinami
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Manuela Porru
- SAFU, IRCCS - Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Chiara Cingolani
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Erica Salvati
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Angela Rizzo
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Carmen D'Angelo
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Eleonora Petti
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Carla Azzurra Amoreo
- Pathology, IRCCS - Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Marcella Mottolese
- Pathology, IRCCS - Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Isabella Sperduti
- Department of Biostatistics Unit, IRCCS - Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Angela Chambery
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Università della Campania Luigi Vanvitelli, via Vivaldi 43, 80100 Caserta
| | - Rosita Russo
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Università della Campania Luigi Vanvitelli, via Vivaldi 43, 80100 Caserta
| | - Paola Ostano
- Cancer Genomics Lab, Fondazione Edo ed Elvo Tempia, via Malta 3, 13900 Biella
| | - Giovanna Chiorino
- Cancer Genomics Lab, Fondazione Edo ed Elvo Tempia, via Malta 3, 13900 Biella
| | - Giovanni Blandino
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Andrea Sacconi
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Julien Cherfils-Vicini
- Université Côte d'Azur, CNRS UMR 7284/INSERM U108, Institute for Research on Cancer and Aging, Nice (IRCAN), Medical School, Nice, France
| | - Carlo Leonetti
- SAFU, IRCCS - Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Eric Gilson
- Université Côte d'Azur, CNRS UMR 7284/INSERM U108, Institute for Research on Cancer and Aging, Nice (IRCAN), Medical School, Nice, France.,Department of Medical Genetics, Archet 2 Hospital, CHU of Nice, France
| | - Annamaria Biroccio
- Oncogenomic and Epigenetic Unit, IRCCS - Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
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15
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The role of telomere-binding modulators in pluripotent stem cells. Protein Cell 2019; 11:60-70. [PMID: 31350723 PMCID: PMC6949317 DOI: 10.1007/s13238-019-0651-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 05/07/2019] [Indexed: 01/24/2023] Open
Abstract
Pluripotent stem cells (PSCs) such as embryonic stem cells (ESCs), ESCs derived by somatic cell nuclear transfer (ntESCs), and induced pluripotent stem cells (iPSCs) have unlimited capacity for self-renewal and pluripotency and can give rise to all types of somatic cells. In order to maintain their self-renewal and pluripotency, PSCs need to preserve their telomere length and homeostasis. In recent years, increasing studies have shown that telomere reprogramming is essential for stem cell pluripotency maintenance and its induced pluripotency process. Telomere-associated proteins are not only required for telomere maintenance in both stem cells, their extra-telomeric functions have also been found to be critical as well. Here, we will discuss how telomeres and telomere-associated factors participate and regulate the maintenance of stem cell pluripotency.
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16
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OCT4 and PAX6 determine the dual function of SOX2 in human ESCs as a key pluripotent or neural factor. Stem Cell Res Ther 2019; 10:122. [PMID: 30999923 PMCID: PMC6471829 DOI: 10.1186/s13287-019-1228-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 03/28/2019] [Accepted: 04/01/2019] [Indexed: 12/19/2022] Open
Abstract
Background Sox2 is a well-established pluripotent transcription factor that plays an essential role in establishing and maintaining pluripotent stem cells (PSCs). It is also thought to be a linage specifier that governs PSC neural lineage specification upon their exiting the pluripotent state. However, the exact role of SOX2 in human PSCs was still not fully understood. In this study, we studied the role of SOX2 in human embryonic stem cells (hESCs) by gain- and loss-of-function approaches and explored the possible underlying mechanisms. Results We demonstrate that knockdown of SOX2 induced hESC differentiation to endoderm-like cells, whereas overexpression of SOX2 in hESCs enhanced their pluripotency under self-renewing culture conditions but promoted their neural differentiation upon replacing the culture to non-self-renewal conditions. We show that this culture-dependent dual function of SOX2 was probably attributed to its interaction with different transcription factors predisposed by the culture environments. Whilst SOX2 interacts with OCT4 under self-renewal conditions, we found that, upon neural differentiation, PAX6, a key neural transcription factor, is upregulated and shows interaction with SOX2. The SOX2-PAX6 complex has different gene regulation pattern from that of SOX2-OCT4 complex. Conclusions Our work provides direct evidence that SOX2 is necessarily required for hESC pluripotency; however, it can also function as a neural factor, depending on the environmental input. OCT4 and PAX6 might function as key SOX2-interacting partners that determine the function of SOX2 in hESCs. Electronic supplementary material The online version of this article (10.1186/s13287-019-1228-7) contains supplementary material, which is available to authorized users.
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17
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Wu Q, Han D, Zhang J, Li X. Expression of telomere repeat binding factor 1 and TRF2 in Alzheimer’s disease and correlation with clinical parameters. Neurol Res 2019; 41:504-509. [PMID: 30761946 DOI: 10.1080/01616412.2019.1580456] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Qi Wu
- The Second Clinical Medical College, Zhengzhou University, Zhengzhou, China
| | - Dongyang Han
- The Second Clinical Medical College, Zhengzhou University, Zhengzhou, China
| | - Jiangkuan Zhang
- The Second Clinical Medical College, Zhengzhou University, Zhengzhou, China
| | - Xin Li
- Department of Neurology, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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18
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The differential spatiotemporal expression pattern of shelterin genes throughout lifespan. Aging (Albany NY) 2018; 9:1219-1232. [PMID: 28437249 PMCID: PMC5425123 DOI: 10.18632/aging.101223] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 04/06/2017] [Indexed: 01/07/2023]
Abstract
Shelterin forms the core complex of telomere proteins and plays critical roles in protecting telomeres against unwanted activation of the DNA damage response and in maintaining telomere length homeostasis. Although shelterin expression is believed to be ubiquitous for stabilization of chromosomal ends. Evidences suggest that some shelterin subunits have tissue-specific functions. However, very little is known regarding how shelterin subunit gene expression is regulated during development and aging. Using two different animal models, the mouse and zebrafish, we reveal herein that shelterin subunits exhibit distinct spatial and temporal expression patterns that do not correlate with the proliferative status of the organ systems examined. Together, this work shows that the shelterin subunits exhibit distinct spatiotemporal expression patterns, suggesting important tissue-specific functions during development and aging.
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19
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Rizzo A, Iachettini S, Salvati E, Zizza P, Maresca C, D'Angelo C, Benarroch-Popivker D, Capolupo A, Del Gaudio F, Cosconati S, Di Maro S, Merlino F, Novellino E, Amoreo CA, Mottolese M, Sperduti I, Gilson E, Biroccio A. SIRT6 interacts with TRF2 and promotes its degradation in response to DNA damage. Nucleic Acids Res 2017; 45:1820-1834. [PMID: 27923994 PMCID: PMC5389694 DOI: 10.1093/nar/gkw1202] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 11/18/2016] [Indexed: 12/29/2022] Open
Abstract
Telomere repeat binding factor 2 (TRF2) has been increasingly recognized to be involved in telomere maintenance and DNA damage response. Here, we show that TRF2 directly binds SIRT6 in a DNA independent manner and that this interaction is increased upon replication stress. Knockdown of SIRT6 up-regulates TRF2 protein levels and counteracts its down-regulation during DNA damage response, leading to cell survival. Moreover, we report that SIRT6 deactetylates in vivo the TRFH domain of TRF2, which in turn, is ubiquitylated in vivo activating the ubiquitin-dependent proteolysis. Notably, overexpression of the TRF2cT mutant failed to be stabilized by SIRT6 depletion, demonstrating that the TRFH domain is required for its post-transcriptional modification. Finally, we report an inverse correlation between SIRT6 and TRF2 protein expression levels in a cohort of colon rectal cancer patients. Taken together our findings describe TRF2 as a novel SIRT6 substrate and demonstrate that acetylation of TRF2 plays a crucial role in the regulation of TRF2 protein stability, thus providing a new route for modulating its expression level during oncogenesis and damage response.
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Affiliation(s)
- Angela Rizzo
- Oncogenomic and Epigenetic Unit, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Sara Iachettini
- Oncogenomic and Epigenetic Unit, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Erica Salvati
- Oncogenomic and Epigenetic Unit, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Pasquale Zizza
- Oncogenomic and Epigenetic Unit, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Carmen Maresca
- Oncogenomic and Epigenetic Unit, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Carmen D'Angelo
- Oncogenomic and Epigenetic Unit, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Delphine Benarroch-Popivker
- Université Côte d'Azur, INSERM U1081 CNRS UMR7284, Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, France
| | - Angela Capolupo
- Department of Pharmacy, PhD Program in Drug Discovery and Development, University of Salerno, Via Giovanni Paolo II 132, Fisciano (SA) 84084, Italy
| | - Federica Del Gaudio
- Department of Pharmacy, PhD Program in Drug Discovery and Development, University of Salerno, Via Giovanni Paolo II 132, Fisciano (SA) 84084, Italy
| | - Sandro Cosconati
- DiSTABiF, Seconda Università di Napoli, Via Vivaldi 43, Caserta 81100, Italy
| | - Salvatore Di Maro
- DiSTABiF, Seconda Università di Napoli, Via Vivaldi 43, Caserta 81100, Italy
| | - Francesco Merlino
- Department of Pharmacy, University of Naples Federico II, Via Montesano 49, Naples 80131, Italy
| | - Ettore Novellino
- Department of Pharmacy, University of Naples Federico II, Via Montesano 49, Naples 80131, Italy
| | - Carla Azzurra Amoreo
- Department of Pathology, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Marcella Mottolese
- Department of Pathology, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Isabella Sperduti
- Biostatistics Unit, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
| | - Eric Gilson
- Université Côte d'Azur, INSERM U1081 CNRS UMR7284, Institute for Research on Cancer and Aging, Nice (IRCAN), Faculty of Medicine, France.,Department of Medical Genetics, Archet 2 Hospital, CHU of Nice, France
| | - Annamaria Biroccio
- Oncogenomic and Epigenetic Unit, Regina Elena National Cancer Institute, Via Elio Chianesi 53, Rome 00144, Italy
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20
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Transcription regulation of CDKN1A (p21/CIP1/WAF1) by TRF2 is epigenetically controlled through the REST repressor complex. Sci Rep 2017; 7:11541. [PMID: 28912501 PMCID: PMC5599563 DOI: 10.1038/s41598-017-11177-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 07/20/2017] [Indexed: 12/13/2022] Open
Abstract
We observed extra-telomeric binding of the telomere repeat binding factor TRF2 within the promoter of the cyclin-dependent kinase CDKNIA (p21/CIP1/WAF1). This result in TRF2 induced transcription repression of p21. Interestingly, p21 repression was through engagement of the REST-coREST-LSD1-repressor complex and altered histone marks at the p21 promoter in a TRF2-dependent fashion. Furthermore, mutational analysis shows p21 repression requires interaction of TRF2 with a p21 promoter G-quadruplex. Physiologically, TRF2-mediated p21 repression attenuated drug-induced activation of cellular DNA damage response by evading G2/M arrest in cancer cells. Together these reveal for the first time role of TRF2 in REST- repressor complex mediated transcription repression.
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21
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Charif R, Granotier-Beckers C, Bertrand HC, Poupon J, Ségal-Bendirdjian E, Teulade-Fichou MP, Boussin FD, Bombard S. Association of a Platinum Complex to a G-Quadruplex Ligand Enhances Telomere Disruption. Chem Res Toxicol 2017; 30:1629-1640. [DOI: 10.1021/acs.chemrestox.7b00131] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Razan Charif
- Université
Paris Descartes, INSERM UMR-S-1007, 45 rue des Saints-Pères, 75006 Paris, France
| | - Christine Granotier-Beckers
- CEA/DRF/IRCM,
Laboratoire de RadioPathologie, INSERM U967, Université Paris
VII, Université Paris XI, 18
route du Panorama, 92265 Fontenay-aux-Roses Cedex, France
| | - Hélène Charlotte Bertrand
- Institut
Curie,
Centre Universitaire Paris Saclay, CNRS UMR9187/INSERM U1196, Bâtiments 110-112, 91405 Orsay, France
- Département
de Chimie, Ecole Normale Supérieure, PSL Research University,
UPMC Univ Paris 06, CNRS, Laboratoire des Biomolécules (LBM), 24 rue Lhomond, 75005 Paris, France
- Sorbonne Universités,
UPMC Univ Paris 06, Ecole Normale Supérieure, CNRS, Laboratoire
des Biomolécules (LBM), 24 rue
Lhomond, 75005 Paris, France
| | - Joël Poupon
- Laboratoire
de Toxicologie-Biologique, Hôpital Lariboisière, 2 rue Ambroise Paré, 75475 Paris, France
| | | | - Marie-Paule Teulade-Fichou
- Institut
Curie,
Centre Universitaire Paris Saclay, CNRS UMR9187/INSERM U1196, Bâtiments 110-112, 91405 Orsay, France
| | - François D. Boussin
- CEA/DRF/IRCM,
Laboratoire de RadioPathologie, INSERM U967, Université Paris
VII, Université Paris XI, 18
route du Panorama, 92265 Fontenay-aux-Roses Cedex, France
| | - Sophie Bombard
- Université
Paris Descartes, INSERM UMR-S-1007, 45 rue des Saints-Pères, 75006 Paris, France
- Institut
Curie,
Centre Universitaire Paris Saclay, CNRS UMR9187/INSERM U1196, Bâtiments 110-112, 91405 Orsay, France
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22
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Harnessing the Potential of Human Pluripotent Stem Cells and Gene Editing for the Treatment of Retinal Degeneration. CURRENT STEM CELL REPORTS 2017; 3:112-123. [PMID: 28596937 PMCID: PMC5445184 DOI: 10.1007/s40778-017-0078-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Purpose of Review A major cause of visual disorders is dysfunction and/or loss of the light-sensitive cells of the retina, the photoreceptors. To develop better treatments for patients, we need to understand how inherited retinal disease mutations result in the dysfunction of photoreceptors. New advances in the field of stem cell and gene editing research offer novel ways to model retinal dystrophies in vitro and present opportunities to translate basic biological insights into therapies. This brief review will discuss some of the issues that should be taken into account when carrying out disease modelling and gene editing of retinal cells. We will discuss (i) the use of human induced pluripotent stem cells (iPSCs) for disease modelling and cell therapy; (ii) the importance of using isogenic iPSC lines as controls; (iii) CRISPR/Cas9 gene editing of iPSCs; and (iv) in vivo gene editing using AAV vectors. Recent Findings Ground-breaking advances in differentiation of iPSCs into retinal organoids and methods to derive mature light sensitive photoreceptors from iPSCs. Furthermore, single AAV systems for in vivo gene editing have been developed which makes retinal in vivo gene editing therapy a real prospect. Summary Genome editing is becoming a valuable tool for disease modelling and in vivo gene editing in the retina.
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Grammatikakis I, Zhang P, Mattson MP, Gorospe M. The long and the short of TRF2 in neurogenesis. Cell Cycle 2016; 15:3026-3032. [PMID: 27565210 DOI: 10.1080/15384101.2016.1222339] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Gene expression patterns change dramatically during neuronal development. Proliferating cells, including neural stem cells (NSCs), express telomere repeat-binding factor 2 (TRF2), a nuclear protein that associates with telomeric proteins, DNA, and RNA telomeres. In NSCs TRF2 also binds to the transcription regulator REST to facilitate repression of numerous neuron-specific genes, thereby keeping the NSCs in a self-renewing state. Upon neuronal differentiation, TRF2 levels decline, REST-regulated neuronal genes are derepressed, and a short isoform of TRF2 arises (TRF2-S) which localizes in the cytoplasm, associates with different subsets of proteins and transcripts, and mobilizes axonal G-rich mRNAs. We recently identified two RNA-binding proteins, HNRNPH1 and H2 (referred to jointly as HNRNPH due to their high homology), which mediate the alternative splicing of an exon required for the expression of full-length TRF2. As HNRNPH levels decline during neurogenesis, TRF2 abundance decreases and TRF2-S accumulates. Here, we discuss the shared and unique functions of TRF2 and TRF2-S, the distinct subcellular compartment in which each isoform resides, the subsets of proteins and nucleic acids with which each interacts, and the functional consequences of these ribonucleoprotein interactions. This paradigm illustrates the dynamic mechanisms through which splicing regulation by factors like HNRNPH enable distinct protein functions as cells adapt to developmental programs such as neurogenesis.
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Affiliation(s)
- Ioannis Grammatikakis
- a Laboratory of Genetics, National Institute on Aging, National Institutes of Health , Baltimore , MD , USA
| | - Peisu Zhang
- b Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health , Baltimore , MD , USA
| | - Mark P Mattson
- b Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health , Baltimore , MD , USA
| | - Myriam Gorospe
- a Laboratory of Genetics, National Institute on Aging, National Institutes of Health , Baltimore , MD , USA
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Grammatikakis I, Zhang P, Panda AC, Kim J, Maudsley S, Abdelmohsen K, Yang X, Martindale JL, Motiño O, Hutchison ER, Mattson MP, Gorospe M. Alternative Splicing of Neuronal Differentiation Factor TRF2 Regulated by HNRNPH1/H2. Cell Rep 2016; 15:926-934. [PMID: 27117401 DOI: 10.1016/j.celrep.2016.03.080] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 02/18/2016] [Accepted: 03/22/2016] [Indexed: 10/21/2022] Open
Abstract
During neuronal differentiation, use of an alternative splice site on the rat telomere repeat-binding factor 2 (TRF2) mRNA generates a short TRF2 protein isoform (TRF2-S) capable of derepressing neuronal genes. However, the RNA-binding proteins (RBPs) controlling this splicing event are unknown. Here, using affinity pull-down analysis, we identified heterogeneous nuclear ribonucleoproteins H1 and H2(HNRNPH) as RBPs specifically capable of interacting with the spliced RNA segment (exon 7) of Trf2 pre-mRNA. HNRNPH proteins prevent the production of the short isoform of Trf2 mRNA, as HNRNPH silencing selectively elevates TRF2-S levels. Accordingly, HNRNPH levels decline while TRF2-S levels increase during neuronal differentiation. In addition, CRISPR/Cas9-mediated deletion of hnRNPH2 selectively accelerates the NGF-triggered differentiation of rat pheochromocytoma cells into neurons. In sum, HNRNPH is a splicing regulator of Trf2 pre-mRNA that prevents the expression of TRF2-S, a factor implicated in neuronal differentiation.
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Affiliation(s)
- Ioannis Grammatikakis
- Laboratory of Genetics, National Institute on Aging-Intramural Research Program, NIH, Baltimore, MD 21224, USA
| | - Peisu Zhang
- Laboratory of Neurosciences, National Institute on Aging-Intramural Research Program, NIH, Baltimore, MD 21224, USA
| | - Amaresh C Panda
- Laboratory of Genetics, National Institute on Aging-Intramural Research Program, NIH, Baltimore, MD 21224, USA
| | - Jiyoung Kim
- Laboratory of Genetics, National Institute on Aging-Intramural Research Program, NIH, Baltimore, MD 21224, USA
| | - Stuart Maudsley
- Translational Neurobiology Group, VIB Department of Molecular Genetics, University of Antwerp, 2610 Antwerpen, Belgium
| | - Kotb Abdelmohsen
- Laboratory of Genetics, National Institute on Aging-Intramural Research Program, NIH, Baltimore, MD 21224, USA
| | - Xiaoling Yang
- Laboratory of Genetics, National Institute on Aging-Intramural Research Program, NIH, Baltimore, MD 21224, USA
| | - Jennifer L Martindale
- Laboratory of Genetics, National Institute on Aging-Intramural Research Program, NIH, Baltimore, MD 21224, USA
| | - Omar Motiño
- Laboratory of Genetics, National Institute on Aging-Intramural Research Program, NIH, Baltimore, MD 21224, USA
| | - Emmette R Hutchison
- Laboratory of Neurosciences, National Institute on Aging-Intramural Research Program, NIH, Baltimore, MD 21224, USA
| | - Mark P Mattson
- Laboratory of Neurosciences, National Institute on Aging-Intramural Research Program, NIH, Baltimore, MD 21224, USA
| | - Myriam Gorospe
- Laboratory of Genetics, National Institute on Aging-Intramural Research Program, NIH, Baltimore, MD 21224, USA.
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Willis DE, Wang M, Brown E, Fones L, Cave JW. Selective repression of gene expression in neuropathic pain by the neuron-restrictive silencing factor/repressor element-1 silencing transcription (NRSF/REST). Neurosci Lett 2015; 625:20-5. [PMID: 26679228 DOI: 10.1016/j.neulet.2015.12.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 11/18/2015] [Accepted: 12/01/2015] [Indexed: 02/07/2023]
Abstract
Neuropathic pain often develops following nerve injury as a result of maladaptive changes that occur in the injured nerve and along the nociceptive pathways of the peripheral and central nervous systems. Multiple cellular and molecular mechanisms likely account for these changes; however, the exact nature of these mechanisms remain largely unknown. A growing number of studies suggest that alteration in gene expression is an important step in the progression from acute to chronic pain states and epigenetic regulation has been proposed to drive this change in gene expression. In this review, we discuss recent evidence that the DNA-binding protein neuron-restrictive silencing factor/repressor element-1 silencing transcription factor (NRSF/REST) is an important component in the development and maintenance of neuropathic pain through its role as a transcriptional regulator for a select subset of genes that it normally represses during development.
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Affiliation(s)
- Dianna E Willis
- Burke Medical Research Institute, 785 Mamaroneck Ave., White Plains, NY 10605, United States; Brain and Mind Research Institute, Weill Cornell Medical College, 1300 York Ave, NY, NY 10065, United States
| | - Meng Wang
- Burke Medical Research Institute, 785 Mamaroneck Ave., White Plains, NY 10605, United States
| | - Elizabeth Brown
- Burke Medical Research Institute, 785 Mamaroneck Ave., White Plains, NY 10605, United States
| | - Lilah Fones
- Burke Medical Research Institute, 785 Mamaroneck Ave., White Plains, NY 10605, United States
| | - John W Cave
- Burke Medical Research Institute, 785 Mamaroneck Ave., White Plains, NY 10605, United States; Brain and Mind Research Institute, Weill Cornell Medical College, 1300 York Ave, NY, NY 10065, United States.
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Ovando-Roche P, Cui W. Identification of Factors in Regulating a Protein Ubiquitination by Immunoprecipitation: a Case Study of TRF2 on Human REST4 Ubiquitination. Bio Protoc 2015; 5:e1525. [PMID: 28748200 DOI: 10.21769/bioprotoc.1525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Ubiquitination is the first step of the ubiquitin-proteasome pathway that regulates cells for their homeostatic functions and is an enzymatic, protein post-translational modification process in which ubiquitin is transferred to a target protein substrate by a set of three ubiquitin enzymes (Weissman et al., 2011; Bhattacharyya et al., 2014; Ristic et al., 2014). Given the importance of this process, it is plausible that ubiquitination is under strict control by many factors and that the regulatory machineries are protein-specific. An assay for the detection of a specific protein ubiquitination will enable us to examine whether a factor has a function to regulate the ubiquitination of this protein. Here we describe a protocol that detects the ubiquitination status of the human REST4 protein in cultured cells, a neural alternative splicing isoform of REST (RE-1 silencing transcription factor), that antagonizes the repressive function of REST on neural differentiation and neuron formation. Using this protocol, we show that the telomere binding protein TRF2 stabilizes the expression of the human REST4 by inhibiting its ubiquitination. This indicates that TRF2 plays a positive role in neural differentiation (Ovando-Roche et al., 2014). This protocol is also useful for the detection of ubiquitination of other proteins of interest.
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Affiliation(s)
- Patrick Ovando-Roche
- Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Faculty of Medicine, Imperial College, London, UK
| | - Wei Cui
- Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Faculty of Medicine, Imperial College, London, UK
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Specific Localization of the Drosophila Telomere Transposon Proteins and RNAs, Give Insight in Their Behavior, Control and Telomere Biology in This Organism. PLoS One 2015; 10:e0128573. [PMID: 26068215 PMCID: PMC4467039 DOI: 10.1371/journal.pone.0128573] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 04/28/2015] [Indexed: 01/02/2023] Open
Abstract
Drosophila telomeres constitute a remarkable exception to the telomerase mechanism. Although maintaining the same cytological and functional properties as telomerase maintain telomeres, Drosophila telomeres embed the telomere retrotransposons whose specific and highly regulated terminal transposition maintains the appropriate telomere length in this organism. Nevertheless, our current understanding of how the mechanism of the retrotransposon telomere works and which features are shared with the telomerase system is very limited. We report for the first time a detailed study of the localization of the main components that constitute the telomeres in Drosophila, HeT-A and TART RNAs and proteins. Our results in wild type and mutant strains reveal localizations of HeT-A Gag and TART Pol that give insight in the behavior of the telomere retrotransposons and their control. We find that TART Pol and HeT-A Gag only co-localize at the telomeres during the interphase of cells undergoing mitotic cycles. In addition, unexpected protein and RNA localizations with a well-defined pattern in cells such as the ovarian border cells and nurse cells, suggest possible strategies for the telomere transposons to reach the oocyte, and/or additional functions that might be important for the correct development of the organism. Finally, we have been able to visualize the telomere RNAs at different ovarian stages of development in wild type and mutant lines, demonstrating their presence in spite of being tightly regulated by the piRNA mechanism.
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Yu JSL, Ramasamy TS, Murphy N, Holt MK, Czapiewski R, Wei SK, Cui W. PI3K/mTORC2 regulates TGF-β/Activin signalling by modulating Smad2/3 activity via linker phosphorylation. Nat Commun 2015; 6:7212. [PMID: 25998442 PMCID: PMC4455068 DOI: 10.1038/ncomms8212] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 04/20/2015] [Indexed: 11/27/2022] Open
Abstract
Crosstalk between the phosphatidylinositol 3-kinase (PI3K) and the transforming growth factor-β signalling pathways play an important role in regulating many cellular functions. However, the molecular mechanisms underpinning this crosstalk remain unclear. Here, we report that PI3K signalling antagonizes the Activin-induced definitive endoderm (DE) differentiation of human embryonic stem cells by attenuating the duration of Smad2/3 activation via the mechanistic target of rapamycin complex 2 (mTORC2). Activation of mTORC2 regulates the phosphorylation of the Smad2/3-T220/T179 linker residue independent of Akt, CDK and Erk activity. This phosphorylation primes receptor-activated Smad2/3 for recruitment of the E3 ubiquitin ligase Nedd4L, which in turn leads to their degradation. Inhibition of PI3K/mTORC2 reduces this phosphorylation and increases the duration of Smad2/3 activity, promoting a more robust mesendoderm and endoderm differentiation. These findings present a new and direct crosstalk mechanism between these two pathways in which mTORC2 functions as a novel and critical mediator. Although crosstalk between the phosphatidylinositol 3-kinase (PI3K) and transforming growth factor-β pathways is important, the mechanism is obscure. Here, Yu et al. show that activation of mTORC2 downstream of PI3K leads to the linker phosphorylation of Smad2/3 and their ubiquitin-dependent degradation.
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Affiliation(s)
- Jason S L Yu
- Department of Surgery and Cancer, Institute of Reproductive and Developmental Biology, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Thamil Selvee Ramasamy
- Department of Surgery and Cancer, Institute of Reproductive and Developmental Biology, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Nick Murphy
- Department of Surgery and Cancer, Institute of Reproductive and Developmental Biology, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Marie K Holt
- Department of Surgery and Cancer, Institute of Reproductive and Developmental Biology, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Rafal Czapiewski
- Department of Surgery and Cancer, Institute of Reproductive and Developmental Biology, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Shi-Khai Wei
- Department of Surgery and Cancer, Institute of Reproductive and Developmental Biology, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Wei Cui
- Department of Surgery and Cancer, Institute of Reproductive and Developmental Biology, Imperial College London, Du Cane Road, London W12 0NN, UK
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NRSF: an Angel or a Devil in Neurogenesis and Neurological Diseases. J Mol Neurosci 2014; 56:131-44. [DOI: 10.1007/s12031-014-0474-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 11/18/2014] [Indexed: 12/12/2022]
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30
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Abstract
Telomeres protect chromosome ends from degradation and inappropriate DNA damage response activation through their association with specific factors. Interestingly, these telomeric factors are able to localize outside telomeric regions, where they can regulate the transcription of genes involved in metabolism, immunity and differentiation. These findings delineate a signalling pathway by which telomeric changes control the ability of their associated factors to regulate transcription. This mechanism is expected to enable a greater diversity of cellular responses that are adapted to specific cell types and telomeric changes, and may therefore represent a pivotal aspect of development, ageing and telomere-mediated diseases.
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