1
|
Huo S, Tang X, Chen W, Gan D, Guo H, Yao Q, Liao R, Huang T, Wu J, Yang J, Xiao G, Han X. Epigenetic regulations of cellular senescence in osteoporosis. Ageing Res Rev 2024; 99:102235. [PMID: 38367814 DOI: 10.1016/j.arr.2024.102235] [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: 09/18/2023] [Revised: 01/27/2024] [Accepted: 02/13/2024] [Indexed: 02/19/2024]
Abstract
Osteoporosis (OP) is a prevalent age-related disease that is characterized by a decrease in bone mineral density (BMD) and systemic bone microarchitectural disorders. With age, senescent cells accumulate and exhibit the senescence-associated secretory phenotype (SASP) in bone tissue, leading to the imbalance of bone homeostasis, osteopenia, changes in trabecular bone structure, and increased bone fragility. Cellular senescence in the bone microenvironment involves osteoblasts, osteoclasts, and bone marrow mesenchymal stem cells (BMSCs), whose effects on bone homeostasis are regulated by epigenetics. Therefore, the epigenetic regulatory mechanisms of cellular senescence have received considerable attention as potential targets for preventing and treating osteoporosis. In this paper, we systematically review the mechanisms of aging-associated epigenetic regulation in osteoporosis, emphasizing the impact of epigenetics on cellular senescence, and summarize three current methods of targeting cellular senescence, which is helpful better to understand the pathogenic mechanisms of cellular senescence in osteoporosis and provides strategies for the development of epigenetic drugs for the treatment of osteoporosis.
Collapse
Affiliation(s)
- Shaochuan Huo
- Shenzhen Hospital of Guangzhou University of Chinese Medicine (Futian), Shenzhen 518000, China; Shenzhen Research Institute of Guangzhou University of Traditional Medicine (Futian), Shenzhen 518000, China
| | - Xinzheng Tang
- Shenzhen Hospital of Guangzhou University of Chinese Medicine (Futian), Shenzhen 518000, China; Shenzhen Research Institute of Guangzhou University of Traditional Medicine (Futian), Shenzhen 518000, China
| | - Weijian Chen
- Guangzhou University of Chinese Medicine, Guangzhou 510405, China
| | - Donghao Gan
- Department of Biochemistry, School of Medicine, Shenzhen Key Laboratory of Cell Microenvironment, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Southern University of Science and Technology, Shenzhen 518055, China
| | - Hai Guo
- Liuzhou Traditional Chinese Medicine Hospital (Liuzhou Zhuang Medical Hospital), Liuzhou 545001, China
| | - Qing Yao
- Department of Biochemistry, School of Medicine, Shenzhen Key Laboratory of Cell Microenvironment, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Southern University of Science and Technology, Shenzhen 518055, China
| | - Rongdong Liao
- Department of Orthopaedics, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - Tingting Huang
- Guangzhou University of Chinese Medicine, Guangzhou 510405, China
| | - Junxian Wu
- Shenzhen Hospital of Guangzhou University of Chinese Medicine (Futian), Shenzhen 518000, China
| | - Junxing Yang
- Shenzhen Hospital of Guangzhou University of Chinese Medicine (Futian), Shenzhen 518000, China; Shenzhen Research Institute of Guangzhou University of Traditional Medicine (Futian), Shenzhen 518000, China.
| | - Guozhi Xiao
- Department of Biochemistry, School of Medicine, Shenzhen Key Laboratory of Cell Microenvironment, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Xia Han
- Shenzhen Hospital of Guangzhou University of Chinese Medicine (Futian), Shenzhen 518000, China; Shenzhen Research Institute of Guangzhou University of Traditional Medicine (Futian), Shenzhen 518000, China.
| |
Collapse
|
2
|
Soto-Castillo JJ, Llavata-Marti L, Fort-Culillas R, Andreu-Cobo P, Moreno R, Codony C, García Del Muro X, Alemany R, Piulats JM, Martin-Liberal J. SWI/SNF Complex Alterations in Tumors with Rhabdoid Features: Novel Therapeutic Approaches and Opportunities for Adoptive Cell Therapy. Int J Mol Sci 2023; 24:11143. [PMID: 37446319 DOI: 10.3390/ijms241311143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/23/2023] [Accepted: 06/29/2023] [Indexed: 07/15/2023] Open
Abstract
The SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin-remodeling complex is one of the most remarkably altered epigenetic regulators in cancer. Pathogenic mutations in genes encoding SWI/SNF-related proteins have been recently described in many solid tumors, including rare and aggressive malignancies with rhabdoid features with no standard therapies in advanced or metastatic settings. In recent years, clinical trials with targeted drugs aimed at restoring its function have shown discouraging results. However, preclinical data have found an association between these epigenetic alterations and response to immune therapy. Thus, the rationale for immunotherapy strategies in SWI/SNF complex alteration-related tumors is strong. Here, we review the SWI/SNF complex and how its dysfunction drives the oncogenesis of rhabdoid tumors and the proposed strategies to revert this alteration and promising novel therapeutic approaches, including immune checkpoint inhibition and adoptive cell therapy.
Collapse
Affiliation(s)
- Juan José Soto-Castillo
- Medical Oncology Department, Catalan Institute of Oncology (ICO), 08908 Hospitalet de Llobregat, Spain
| | - Lucía Llavata-Marti
- Medical Oncology Department, Catalan Institute of Oncology (ICO), 17007 Girona, Spain
| | - Roser Fort-Culillas
- Medical Oncology Department, Catalan Institute of Oncology (ICO), 17007 Girona, Spain
| | - Pablo Andreu-Cobo
- Medical Oncology Department, Parc Tauli Hospital Universitari, 08208 Sabadell, Spain
| | - Rafael Moreno
- Cancer Immunotherapy Group, iPROCURE Program, Bellvitge Biomedical Research Institute (IDIBELL), Catalan Institute of Oncology (ICO), 08908 Hospitalet de Llobregat, Spain
| | - Carles Codony
- Cancer Immunotherapy Group, iPROCURE Program, Bellvitge Biomedical Research Institute (IDIBELL), Catalan Institute of Oncology (ICO), 08908 Hospitalet de Llobregat, Spain
| | - Xavier García Del Muro
- Medical Oncology Department, Catalan Institute of Oncology (ICO), 08908 Hospitalet de Llobregat, Spain
| | - Ramon Alemany
- Cancer Immunotherapy Group, iPROCURE Program, Bellvitge Biomedical Research Institute (IDIBELL), Catalan Institute of Oncology (ICO), 08908 Hospitalet de Llobregat, Spain
| | - Josep M Piulats
- Medical Oncology Department, Catalan Institute of Oncology (ICO), 08908 Hospitalet de Llobregat, Spain
- Cancer Immunotherapy Group, iPROCURE Program, Bellvitge Biomedical Research Institute (IDIBELL), Catalan Institute of Oncology (ICO), 08908 Hospitalet de Llobregat, Spain
| | - Juan Martin-Liberal
- Medical Oncology Department, Catalan Institute of Oncology (ICO), 08908 Hospitalet de Llobregat, Spain
| |
Collapse
|
3
|
Molecular Crosstalk between Chromatin Remodeling and Tumor Microenvironment in Multiple Myeloma. Curr Oncol 2022; 29:9535-9549. [PMID: 36547163 PMCID: PMC9777166 DOI: 10.3390/curroncol29120749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/28/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
Multiple myeloma (MM) is a complex disease driven by numerous genetic and epigenetic alterations that are acquired over time. Despite recent progress in the understanding of MM pathobiology and the availability of innovative drugs, which have pronounced clinical outcome, this malignancy eventually progresses to a drug-resistant lethal stage and, thus, novel therapeutic drugs/models always play an important role in effective management of MM. Modulation of tumor microenvironment is one of the hallmarks of cancer biology, including MM, which affects the myeloma genomic architecture and disease progression subtly through chromatin modifications. The bone marrow niche has a prime role in progression, survival, and drug resistance of multiple myeloma cells. Therefore, it is important to develop means for targeting the ecosystem between multiple myeloma bone marrow microenvironment and chromatin remodeling. Extensive gene expression profile analysis has indeed provided the framework for new risk stratification of MM patients and identifying novel molecular targets and therapeutics. However, key tumor microenvironment factors/immune cells and their interactions with chromatin remodeling complex proteins that drive MM cell growth and progression remain grossly undefined.
Collapse
|
4
|
Gong W, Luo C, Peng F, Xiao J, Zeng Y, Yin B, Chen X, Li S, He X, Liu Y, Cao H, Xu J, Long H. Brahma-related gene-1 promotes tubular senescence and renal fibrosis through Wnt/β-catenin/autophagy axis. Clin Sci (Lond) 2021; 135:1873-1895. [PMID: 34318888 PMCID: PMC8358963 DOI: 10.1042/cs20210447] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/09/2021] [Accepted: 07/28/2021] [Indexed: 02/06/2023]
Abstract
Although accelerated cellular senescence is closely related to the progression of chronic kidney disease (CKD) and renal fibrosis, the underlying mechanisms remain largely unknown. Here, we reported that tubular aberrant expression of Brahma-related gene 1 (BRG1), an enzymatic subunit of the SWItch/Sucrose Non-Fermentable complex, is critically involved in tubular senescence and renal fibrosis. BRG1 was significantly up-regulated in the kidneys, predominantly in tubular epithelial cells, of both CKD patients and unilateral ureteral obstruction (UUO) mice. In vivo, shRNA-mediated knockdown of BRG1 significantly ameliorated renal fibrosis, improved tubular senescence, and inhibited UUO-induced activation of Wnt/β-catenin pathway. In mouse renal tubular epithelial cells (mTECs) and primary renal tubular cells, inhibition of BRG1 diminished transforming growth factor-β1 (TGF-β1)-induced cellular senescence and fibrotic responses. Correspondingly, ectopic expression of BRG1 in mTECs or normal kidneys increased p16INK4a, p19ARF, and p21 expression and senescence-associated β-galactosidase (SA-β-gal) activity, indicating accelerated tubular senescence. Additionally, BRG1-mediated pro-fibrotic responses were largely abolished by small interfering RNA (siRNA)-mediated p16INK4a silencing in vitro or continuous senolytic treatment with ABT-263 in vivo. Moreover, BRG1 activated the Wnt/β-catenin pathway, which further inhibited autophagy. Pharmacologic inhibition of the Wnt/β-catenin pathway (ICG-001) or rapamycin (RAPA)-mediated activation of autophagy effectively blocked BRG1-induced tubular senescence and fibrotic responses, while bafilomycin A1 (Baf A1)-mediated inhibition of autophagy abolished the effects of ICG-001. Further, BRG1 altered the secretome of senescent tubular cells, which promoted proliferation and activation of fibroblasts. Taken together, our results indicate that BRG1 induces tubular senescence by inhibiting autophagy via the Wnt/β-catenin pathway, which ultimately contributes to the development of renal fibrosis.
Collapse
Affiliation(s)
- Wangqiu Gong
- Department of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - Congwei Luo
- Department of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - Fenfen Peng
- Department of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - Jing Xiao
- Department of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - Yiqun Zeng
- Department of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - Bohui Yin
- Department of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - Xiaowen Chen
- Department of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - Shuting Li
- Department of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - Xiaoyang He
- Department of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - Yanxia Liu
- Department of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - Huihui Cao
- Traditional Chinese Pharmacological Laboratory, Third Level Research Laboratory of State Administration of Traditional Chinese Medicine, School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China
| | - Jiangping Xu
- School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Haibo Long
- Department of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| |
Collapse
|
5
|
Yang L, Xia H, Smith K, Gilbertsen A, Beisang D, Kuo J, Bitterman PB, Henke CA. A CD44/Brg1 nuclear complex confers mesenchymal progenitor cells with enhanced fibrogenicity in idiopathic pulmonary fibrosis. JCI Insight 2021; 6:144652. [PMID: 33822772 PMCID: PMC8262361 DOI: 10.1172/jci.insight.144652] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 03/25/2021] [Indexed: 12/22/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease. We previously identified fibrogenic mesenchymal progenitor cells (MPCs) in the lungs of patients with IPF who serve as drivers of progressive fibrosis. Recent single-cell RNA sequencing work revealed that IPF MPCs with the highest transcriptomic network entropy differ the most from control MPCs and that increased CD44 was a marker of these IPF MPCs. We hypothesize that IPF MPCs with high CD44 (CD44hi) expression will display enhanced fibrogenicity. We demonstrate that CD44-expressing MPCs are present at the periphery of the IPF fibroblastic focus, placing them in regions of active fibrogenesis. In a humanized mouse xenograft model, CD44hi IPF MPCs are more fibrogenic than CD44lo IPF MPCs, and knockdown of CD44 diminishes their fibrogenicity. CD44hi IPF MPCs display increased expression of pluripotency markers and enhanced self-renewal compared with CD44lo IPF MPCs, properties potentiated by IL-8. The mechanism involves the accumulation of CD44 within the nucleus, where it associates with the chromatin modulator protein Brahma-related gene 1 (Brg1) and the zinc finger E-box binding homeobox 1 (Zeb1) transcription factor. This CD44/Brg1/Zeb1 nuclear protein complex targets the Sox2 gene, promoting its upregulation and self-renewal. Our data implicate CD44 interaction with the epigenetic modulator protein Brg1 in conveying IPF MPCs with cell-autonomous fibrogenicity.
Collapse
Affiliation(s)
| | | | | | | | - Daniel Beisang
- Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota, USA
| | | | | | | |
Collapse
|
6
|
Dong W, Zhu Y, Zhang Y, Fan Z, Zhang Z, Fan X, Xu Y. BRG1 Links TLR4 Trans-Activation to LPS-Induced SREBP1a Expression and Liver Injury. Front Cell Dev Biol 2021; 9:617073. [PMID: 33816466 PMCID: PMC8012493 DOI: 10.3389/fcell.2021.617073] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 02/26/2021] [Indexed: 12/12/2022] Open
Abstract
Multiple organ failure is one of the most severe consequences in patients with septic shock. Liver injury is frequently observed during this pathophysiological process. In the present study we investigated the contribution of Brahma related gene 1 (BRG1), a chromatin remodeling protein, to septic shock induced liver injury. When wild type (WT) and liver conditional BRG1 knockout (LKO) mice were injected with lipopolysaccharide (LPS), liver injury was appreciably attenuated in the LKO mice compared to the WT mice as evidenced by plasma ALT/AST levels, hepatic inflammation and apoptosis. Of interest, there was a down-regulation of sterol response element binding protein 1a (SREBP1a), known to promote liver injury, in the LKO livers compared to the WT livers. BRG1 did not directly bind to the SREBP1a promoter. Instead, BRG1 was recruited to the toll-like receptor 4 (TLR4) promoter and activated TLR4 transcription. Ectopic TLR4 restored SREBP1a expression in BRG1-null hepatocytes. Congruently, adenovirus carrying TLR4 or SREBP1a expression vector normalized liver injury in BRG1 LKO mice injected with LPS. Finally, a positive correlation between BRG1 and TLR4 expression was detected in human liver biopsy specimens. In conclusion, our data demonstrate that a BRG1-TLR4-SREBP1a axis that mediates LPS-induced liver injury in mice.
Collapse
Affiliation(s)
- Wenhui Dong
- Key Laboratory of Targeted Invention of Cardiovascular Disease and Collaborative Innovation Center for Cardiovascular Translational Medicine, Department of Pathophysiology, Nanjing Medical University, Nanjing, China
| | - Yuwen Zhu
- Key Laboratory of Targeted Invention of Cardiovascular Disease and Collaborative Innovation Center for Cardiovascular Translational Medicine, Department of Pathophysiology, Nanjing Medical University, Nanjing, China
| | - Yangxi Zhang
- Key Laboratory of Targeted Invention of Cardiovascular Disease and Collaborative Innovation Center for Cardiovascular Translational Medicine, Department of Pathophysiology, Nanjing Medical University, Nanjing, China
| | - Zhiwen Fan
- Department of Pathology, Affiliated Nanjing Drum Tower Hospital of Nanjing University School of Medicine, Nanjing, China
| | - Ziyu Zhang
- Key Laboratory of Women's Reproductive Health of Jiangxi, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, China.,Central Laboratory, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, China
| | - Xiangshan Fan
- Department of Pathology, Affiliated Nanjing Drum Tower Hospital of Nanjing University School of Medicine, Nanjing, China
| | - Yong Xu
- Key Laboratory of Targeted Invention of Cardiovascular Disease and Collaborative Innovation Center for Cardiovascular Translational Medicine, Department of Pathophysiology, Nanjing Medical University, Nanjing, China.,Institute of Biomedical Research, Liaocheng University, Liaocheng, China
| |
Collapse
|
7
|
ATP-Dependent Chromatin Remodeling Complex in the Lineage Specification of Mesenchymal Stem Cells. Stem Cells Int 2020; 2020:8839703. [PMID: 32963551 PMCID: PMC7499328 DOI: 10.1155/2020/8839703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 08/29/2020] [Accepted: 09/01/2020] [Indexed: 02/06/2023] Open
Abstract
Mesenchymal stem cells (MSCs) present in multiple tissues can self-renew and differentiate into multiple lineages including the bone, cartilage, muscle, cardiac tissue, and connective tissue. Key events, including cell proliferation, lineage commitment, and MSC differentiation, are ensured by precise gene expression regulation. ATP-dependent chromatin alteration is one form of epigenetic modifications that can regulate the transcriptional level of specific genes by utilizing the energy from ATP hydrolysis to reorganize chromatin structure. ATP-dependent chromatin remodeling complexes consist of a variety of subunits that together perform multiple functions in self-renewal and lineage specification. This review highlights the important role of ATP-dependent chromatin remodeling complexes and their different subunits in modulating MSC fate determination and discusses the proposed mechanisms by which ATP-dependent chromatin remodelers function.
Collapse
|
8
|
Swer PB, Sharma R. ATP-dependent chromatin remodelers in ageing and age-related disorders. Biogerontology 2020; 22:1-17. [PMID: 32968929 DOI: 10.1007/s10522-020-09899-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 09/16/2020] [Indexed: 11/27/2022]
Abstract
Ageing is characterized by the perturbation in cellular homeostasis associated with genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion and altered intracellular communication. Changes in the epigenome represent one of the crucial mechanisms during ageing and in age-related disorders. The ATP-dependent chromatin remodelers are an evolutionarily conserved family of nucleosome remodelling factors and generally regulate DNA repair, replication, recombination, transcription and cell cycle. Here, we review the chromatin based epigenetic changes that occur in ageing and age-related disorders with a specific reference to chromatin remodelers. We also discuss the link between dietary restriction and chromatin remodelers in regulating age-related processes with a view for consideration in future intervention studies.
Collapse
Affiliation(s)
- Pynskhem Bok Swer
- Department of Biochemistry, North-Eastern Hill University, Shillong, 793022, India
| | - Ramesh Sharma
- Department of Biochemistry, North-Eastern Hill University, Shillong, 793022, India.
| |
Collapse
|
9
|
Epigenetic Regulation in Mesenchymal Stem Cell Aging and Differentiation and Osteoporosis. Stem Cells Int 2020; 2020:8836258. [PMID: 32963550 PMCID: PMC7501554 DOI: 10.1155/2020/8836258] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/17/2020] [Accepted: 08/24/2020] [Indexed: 02/06/2023] Open
Abstract
Mesenchymal stem cells (MSCs) are a reliable source for cell-based regenerative medicine owing to their multipotency and biological functions. However, aging-induced systemic homeostasis disorders in vivo and cell culture passaging in vitro induce a functional decline of MSCs, switching MSCs to a senescent status with impaired self-renewal capacity and biased differentiation tendency. MSC functional decline accounts for the pathogenesis of many diseases and, more importantly, limits the large-scale applications of MSCs in regenerative medicine. Growing evidence implies that epigenetic mechanisms are a critical regulator of the differentiation programs for cell fate and are subject to changes during aging. Thus, we here review epigenetic dysregulations that contribute to MSC aging and osteoporosis. Comprehending detailed epigenetic mechanisms could provide us with a novel horizon for dissecting MSC-related pathogenesis and further optimizing MSC-mediated regenerative therapies.
Collapse
|
10
|
Sinha S, Biswas M, Chatterjee SS, Kumar S, Sengupta A. Pbrm1 Steers Mesenchymal Stromal Cell Osteolineage Differentiation by Integrating PBAF-Dependent Chromatin Remodeling and BMP/TGF-β Signaling. Cell Rep 2020; 31:107570. [DOI: 10.1016/j.celrep.2020.107570] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 02/17/2020] [Accepted: 04/02/2020] [Indexed: 12/31/2022] Open
|
11
|
Finetti MA, Grabovska Y, Bailey S, Williamson D. Translational genomics of malignant rhabdoid tumours: Current impact and future possibilities. Semin Cancer Biol 2020; 61:30-41. [PMID: 31923457 DOI: 10.1016/j.semcancer.2019.12.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 12/15/2019] [Accepted: 12/16/2019] [Indexed: 12/24/2022]
Abstract
Malignant Rhabdoid Tumours (MRT) are the quintessential example of an epigenetic cancer. Mutation of a single gene, SMARCB1 or more rarely SMARCA4, is capable of causing one of the most aggressive and lethal cancers of early childhood and infancy. SMARCB1 encodes a core subunit of the SWI/SNF complex and its mutation evokes genome-wide downstream effects which may be counteracted therapeutically. Here we review and discuss the use of translational genomics in the study of MRT biology and the ways in which this has impacted clinical practice or may do so in the future. First, the diagnosis and definition of MRT and the transition from a histopathological to a molecular definition. Second, epigenetic and transcriptomic subgroups within MRT, their defining features and potential prognostic or therapeutic significance. Third, functional genomic studies of MRT by mouse modelling and forced re-expression of SMARCB1 in MRT cells. Fourth, studies of underlying epigenetic mechanisms (e.g. EZH2, HDACs) or deregulated kinases (e.g. PDGFR, FGFR1) and the potential therapeutic opportunities these provide. Finally, we discuss likely future directions and proffer opinion on how future translational genomics should be integrated into future biological/clinical studies to select and evaluate the best anti-MRT therapeutic agents.
Collapse
Affiliation(s)
- Martina A Finetti
- Wolfson Childhood Cancer Research Centre, Northern Institute for Cancer Research, Newcastle University, Newcastle Upon Tyne, UK
| | - Yura Grabovska
- Wolfson Childhood Cancer Research Centre, Northern Institute for Cancer Research, Newcastle University, Newcastle Upon Tyne, UK
| | - Simon Bailey
- Wolfson Childhood Cancer Research Centre, Northern Institute for Cancer Research, Newcastle University, Newcastle Upon Tyne, UK
| | - Daniel Williamson
- Wolfson Childhood Cancer Research Centre, Northern Institute for Cancer Research, Newcastle University, Newcastle Upon Tyne, UK.
| |
Collapse
|
12
|
He L, Chen Y, Feng J, Sun W, Li S, Ou M, Tang L. Cellular senescence regulated by SWI/SNF complex subunits through p53/p21 and p16/pRB pathway. Int J Biochem Cell Biol 2017; 90:29-37. [PMID: 28716547 DOI: 10.1016/j.biocel.2017.07.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 07/02/2017] [Accepted: 07/13/2017] [Indexed: 01/16/2023]
Abstract
SWI/SNF complex is an evolutionarily well-conserved chromatin-remodeling complex, which is implicated in the nucleosomes removing or sliding, impacting on the DNA repair, replication and genes expression regulation. The SWI/SNF complex consists up to 12 protein subunits. The catalytic subunits are BRG1 or BRM, which are exclusive ATPase subunits. BRG1 has been reported to play an important role in cellular senescence. However, The function of non-catalytic subunits involved in cellular senescence is rarely investigated. Therefore, we focused on the senescence regulation roles of SWI/SNF non-catalytic subunits in cellular senescent model induced by H2O2. H2O2 treatment was used to induce cellular senescence models in vitro. Screening the candidate subunits involved in this process by comparing the expression levels of SWI/SNF subunits with/without H2O2 treatment. Over-expression and knockdown the candidate subunits were utilized to investigate the functions and mechanism of the subunits involved in senescence regulation. The expressions of BAF57, BAF60a and SNF5 were changed significantly after H2O2 treatment. Overexpression of the three subunits separately induced cell growth arrest in both HaCaT and GLL19 cells, while knockdown of the subunits separately eased the senescence induced by H2O2 treatment. Results further showed that BAF57, BAF60a and SNF5 regulated cellular senescence via both p53/p21 and p16/pRB pathways, and the three subunits all had a directly interaction with p53. These results indicated that BAF57, BAF60a and SNF5 might act as novel pro-senescence factors in both normal and tumor human skin cells. Therefore, inhibiting expression of the three factors might delay the cellular senescence process.
Collapse
Affiliation(s)
- Ling He
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China
| | - Ying Chen
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China
| | - Jianguo Feng
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China; Department of Anesthesiology, The Affiliated Hospital of Southwest Medical University, China
| | - Weichao Sun
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China
| | - Shun Li
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China
| | - Mengting Ou
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China
| | - Liling Tang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China.
| |
Collapse
|
13
|
Wang G, Fu Y, Hu F, Lan J, Xu F, Yang X, Luo X, Wang J, Hu J. Loss of BRG1 induces CRC cell senescence by regulating p53/p21 pathway. Cell Death Dis 2017; 8:e2607. [PMID: 28182012 PMCID: PMC5386468 DOI: 10.1038/cddis.2017.1] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 11/21/2016] [Accepted: 11/29/2016] [Indexed: 12/18/2022]
Abstract
Brahma-related gene-1 (BRG1) is the specific ATPase of switch/sucrose nonfermentable chromatin-remodeling complex that is aberrantly expressed or mutated in various cancers. However, the exact role of BRG1 in oncogenesis remains unknown. In this study, we demonstrate that the knockdown (KD) of BRG1 promotes cellular senescence by influencing the SIRT1/p53/p21 signal axis in colorectal cancer (CRC). In particular, we reveal that the expression level of BRG1 is inversely correlated with p21, one of the classic senescence regulators, and is decreased in senescent CRC cells. KD of BRG1 promoting senescence is indicated by the increase of senescence-associated β-galactosidase (SA-β-gal) activity, inhibition of cell proliferation, induction of cell cycle arrest, and formation of senescence-associated heterochromatin foci. BRG1 binds to SIRT1 and interferes with SIRT1-mediated deacetylation of p53 at K382. Rescue experiments by co-silencing p53 or treatment with EX527, a SIRT1-specific inhibitor, abrogated the cellular senescence induced by KD of BRG1. BRG1 KD cells resulted in smaller tumor formation than that in control cells in vivo. Collectively, our study shows that BRG1 has an important role in cellular senescence and tumor growth. The BRG1/SIRT1/p53 signal axis is a novel mechanism of cell senescence in CRC and is a new potential target for cancer therapy.
Collapse
Affiliation(s)
- Guihua Wang
- Cancer Research Institute, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Yinjia Fu
- Cancer Research Institute, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Fuqing Hu
- Cancer Research Institute, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Jinqing Lan
- Cancer Research Institute, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Feng Xu
- Cancer Research Institute, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Xi Yang
- Cancer Research Institute, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Xuelai Luo
- Cancer Research Institute, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Jing Wang
- Department of Immunology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Junbo Hu
- Cancer Research Institute, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| |
Collapse
|
14
|
Kim DR, Lee JE, Shim KJ, Cho JH, Lee HC, Park SK, Chang MS. Effects of herbal Epimedium on the improvement of bone metabolic disorder through the induction of osteogenic differentiation from bone marrow-derived mesenchymal stem cells. Mol Med Rep 2016; 15:125-130. [PMID: 27959402 PMCID: PMC5355742 DOI: 10.3892/mmr.2016.6015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 11/03/2016] [Indexed: 02/06/2023] Open
Abstract
Herbal Epimedium (HE) has been commonly used as a tonic, antirheumatic agent and in the treatment of bone-associated diseases including osteoporosis. Treatment for osteoporosis is important to increase bone mass density and maintain to balance of bone remodeling. The present study was performed to investigate the effects of HE on mouse bone marrow mesenchymal stem cell (mBMMSC) proliferation and osteogenic differentiation, using MTT assays, proliferating cell nuclear antigen (PCNA) detection and apoptosis and differentiation assays. HE was demonstrated to inhibit the proliferation of mBMMSCs up to 45.43±3.33% and to decrease the level of PCNA expression compared with untreated cells. HE also induced late apoptosis at 24 and 48 h after treatment up to 71.93 and 67.03%, respectively, while only 14.93% of untreated cells exhibited apoptosis. By contrast, HE induced differentiation of mBMMSCs into an osteogenic lineage at the beginning of three weeks after commencement of treatment. This suggested that HE is a candidate as an inducer of osteogenesis from bone marrow mesenchymal stem cells, and additionally has potential for use in the treatment of bone metabolic disorders such as osteoporosis.
Collapse
Affiliation(s)
- Do Rim Kim
- Department of Prescriptionology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Ji Eun Lee
- Department of Prescriptionology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Kyung Jun Shim
- Department of Prescriptionology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Jin Hyoung Cho
- Department of Prescriptionology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Ho Chul Lee
- Department of Prescriptionology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Seong Kyu Park
- Department of Prescriptionology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Mun Seog Chang
- Department of Prescriptionology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| |
Collapse
|
15
|
Hou H, Xing W, Li W. Brahma-related gene 1 induces apoptosis in a p53-dependent manner in human rheumatoid fibroblast-like synoviocyte MH7A. Medicine (Baltimore) 2016; 95:e5241. [PMID: 28002318 PMCID: PMC5181802 DOI: 10.1097/md.0000000000005241] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Blocked apoptosis and aggressive inflammatory responses occur in fibroblast-like synoviocyte (FLS) of rheumatoid arthritis (RA) patients. Although Brahma-related gene 1 (BRG1) is considered as a tumor suppressor, few research covers its role in RA. This study aims to reveal effects and potential mechanisms of BRG1 in human FLS cell line MH7A.BRG1 expression in MH7A cells was altered by transfection of overexpression vectors or short hairpin RNAs (shRNAs). Cell viability and apoptosis were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry after transfection. Factors involved in inflammation and apoptosis were quantified by qPCR and Western blot. The interaction between BRG1 and p53 was assessed by immunoprecipitation (IP).Results showed that BRG1 overexpression significantly suppressed MH7A cell viability and induced apoptosis (P < 0.01), and its knockdown had opposite effects. BRG1 reduced mRNA levels of matrix metallopeptidase 3, TIMP metallopeptidase inhibitor 2, cyclooxygenase 2, and interleukin 6, implying its suppressive effects on inflammation. BRG1 interacted with and promoted p53 (P < 0.05). B-cell chronic lymphocytic leukemia/lymphoma 2 was suppressed (P < 0.05), while cytochrome c, caspase 3 (CASP3) and CASP9 were activated (P < 0.01) by BRG1. However, the regulation on these factors was abrogated by p53 knockdown (P < 0.01).These findings suggest that BRG1 may induce apoptosis and suppress inflammation in MH7A cells. Potential functional mechanisms involve the regulation of apoptotic factors by BRG1, which may depend on the recruitment and promotion of p53. This study provides the essential proof for applying BRG1 to the molecular therapy of RA.
Collapse
|
16
|
|
17
|
Guo J, Zhang T, Yu J, Li HZ, Zhao C, Qiu J, Zhao B, Zhao J, Li W, Zhao TZ. Neuroprotective effects of a chromatin modifier on ischemia/reperfusion neurons: implication of its regulation of BCL2 transactivation by ERα signaling. Cell Tissue Res 2016; 364:475-488. [PMID: 26728277 DOI: 10.1007/s00441-015-2347-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 12/10/2015] [Indexed: 12/26/2022]
Abstract
An understanding of the molecular mechanisms involved in the regulation of estrogen receptor alpha (ERα)-mediated neuroprotective effects is valuable for the development of therapeutic strategy against neuronal ischemic injury. Here, we report the upregulated expression of metastasis-associated protein 1 (MTA1), a master chromatin modifier and transcriptional regulator, in the murine middle cerebral artery occlusion (MCAO) model. Inhibition of MTA1 expression by in vivo short interfering RNA treatment potentiated neuronal apoptosis in a caspase-3-dependent manner and thereafter aggravated MCAO-induced neuronal damage. Mechanistically, the pro-survival effects of MTA1 required the participation of ERα signaling. We also provide in vitro evidence that MTA1 enhances the binding of ERα with the BCL2 promoter upon ischemic insults via recruitment of HDAC2 together with other unidentified coregulators, thus promoting the ERα-mediated transactivation of the BCL2 gene. Collectively, our results suggest that the augmentation of endogenous MTA1 expression during neuronal ischemic injury acts additionally to an endocrinous cascade orchestrating intimate interactions between ERα and BCL2 pathways and operates as an indispensable defensive mechanism in response to neuronal ischemia/reperfusion stress. Future studies in this field will shed light on the modulation of the complicated neuroprotective effects by estrogen signaling.
Collapse
Affiliation(s)
- Jun Guo
- Department of Neurology, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710038, People's Republic of China
| | - Tao Zhang
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710038, People's Republic of China
| | - Jia Yu
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710038, People's Republic of China
| | - Hong-Zeng Li
- Department of Neurology, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710038, People's Republic of China
| | - Cong Zhao
- Department of Neurology, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710038, People's Republic of China
| | - Jing Qiu
- Department of Neurology, General Hospital of Shenyang Military Command, Shenyang, 110015, People's Republic of China
| | - Bo Zhao
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710038, People's Republic of China
| | - Jie Zhao
- Department of Histology and Embryology, Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Wei Li
- Department of Histology and Embryology, Fourth Military Medical University, Xi'an, 710032, People's Republic of China.
| | - Tian-Zhi Zhao
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710038, People's Republic of China.
| |
Collapse
|
18
|
Squillaro T, Severino V, Alessio N, Farina A, Di Bernardo G, Cipollaro M, Peluso G, Chambery A, Galderisi U. De-regulated expression of the BRG1 chromatin remodeling factor in bone marrow mesenchymal stromal cells induces senescence associated with the silencing of NANOG and changes in the levels of chromatin proteins. Cell Cycle 2016; 14:1315-26. [PMID: 25724006 DOI: 10.4161/15384101.2014.995053] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Stem cells have a peculiar chromatin architecture that contributes to their unique properties, including uncommitted status, multi/pluripotency and self-renewal. We analyzed the effect of the de-regulation of the SWI/SNF chromatin remodeling complex in mesenchymal stromal cells (MSC) through the silencing and up-regulation of BRG1, which is the ATPase subunit of the complex. The altered expression of BRG1 promoted the senescence of MSC with suppression of the NANOG transcription, which is part of the transcriptional circuitry governing stem cell functions. To gain insight on the way NANOG was silenced, we evaluated how the de-regulated BRG1 expression affect the binding of activators and repressors on the NANOG promoter. We found 4 E2F binding motifs on NANOG promoter, which can be occupied by RB1 and RB2/P130. These are members of the retinoblastoma gene family. In MSC with a silenced BRG1, the relative binding of the 2 retinoblastoma proteins increased, and this was associated with the recruitment of DNMT1. This induced the methylation of CpG on the NANOG promoter. Opposingly, when a high level of BRG1 was present, the same E2F binding motifs were docking sites for BRG1, which induced chromatin compaction without CpG methylation but with increased histone deacetylation, associated with the presence of HDAC1 on E2F binding sites. Besides the sharp regulation of the NANOG expression, we evidenced, through proteomic analysis, that the de-regulation of the SWI/SNF function affected the expression of histones and other nuclear proteins involved in "nuclear architecture," suggesting that BRG1 may act as global regulator of gene expression.
Collapse
Affiliation(s)
- Tiziana Squillaro
- a Department of Experimental Medicine; Biotechnology and Molecular Biology Section ; Second University of Naples ; Naples , Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Yuan Y, Wang C, Xu J, Tao J, Xu Z, Huang S. BRG1 overexpression in smooth muscle cells promotes the development of thoracic aortic dissection. BMC Cardiovasc Disord 2014; 14:144. [PMID: 25304030 PMCID: PMC4531522 DOI: 10.1186/1471-2261-14-144] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 10/03/2014] [Indexed: 01/19/2023] Open
Abstract
Background Here we investigated Brahma-related gene 1 (BRG1) expression in aortic smooth muscle cells (SMCs) and its role in the regulation of the pathological changes in aortic SMCs of thoracic arotic dissection (TAD). Methods BRG1, matrix metalloproteinase 2 (MMP2), and MMP9 mRNA and protein expression in human aortic specimens were examined by qPCR and western blot, respectively. The percentage of apoptotic and contractile SMCs in aortic specimens were determined by TUNEL assay and α-SMA immunohistochemical staining, respectively. The role of BRG1 in MMP2 and MMP9 expression, cell apoptosis, and phenotype transition in aortic SMCs were investigated using a human aortic SMC line via adenovirus mediated gene transfer. MMPs mRNA and protein levels were analyzed by qPCR and western blot, respectively. The percentage of apoptotic and contractile cells were determined through flow cytometry analysis. Results The expression level of BRG1 in the aortic walls (adventitia-removed) was significantly higher in the TAD than the normal group. BRG1 expression was positively correlated to expression of MMP2 and MMP9 and SMC apoptosis, but was negatively correlated to the percentage of contractile aortic SMCs in TAD specimens. In human aortic SMC line, BRG1 transfection led to significant upregulation of MMP2 and MMP9 expression and a concomitant increase in SMC apoptosis as well as a decrease in the percentage of contractile phenotype of cells. Conclusions BRG1 is significantly upregulated in the aortic SMCs of TAD, and its overexpression might promote the development of TAD by increasing MMP2 and MMP9 expression, inducing SMC apoptosis and the transition from contractile to synthetic phenotype.
Collapse
Affiliation(s)
- Yang Yuan
- Institute of Cardiothoracic Surgery, Changhai Hospital, Second Military Medical University, 168, Changhai Rd, Shanghai, P. R. China.
| | - Chong Wang
- Department of Cardiothoracic Surgery, Changhai Hospital, Second Military Medical University, 168, Changhai Rd., Shanghai, P. R. China.
| | - Jibin Xu
- Department of Cardiothoracic Surgery, Changhai Hospital, Second Military Medical University, 168, Changhai Rd., Shanghai, P. R. China.
| | - Jin Tao
- Institute of Cardiothoracic Surgery, Changhai Hospital, Second Military Medical University, 168, Changhai Rd, Shanghai, P. R. China.
| | - Zhiyun Xu
- Department of Cardiothoracic Surgery, Changhai Hospital, Second Military Medical University, 168, Changhai Rd., Shanghai, P. R. China.
| | - Shengdong Huang
- Institute of Cardiothoracic Surgery, Changhai Hospital, Second Military Medical University, 168, Changhai Rd, Shanghai, P. R. China.
| |
Collapse
|
20
|
Wang S, Zhang X, Yuan Y, Tan M, Zhang L, Xue X, Yan Y, Han L, Xu Z. BRG1 expression is increased in thoracic aortic aneurysms and regulates proliferation and apoptosis of vascular smooth muscle cells through the long non-coding RNA HIF1A-AS1 in vitro. Eur J Cardiothorac Surg 2014; 47:439-46. [DOI: 10.1093/ejcts/ezu215] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
|
21
|
Lee HJ, Choi JH, Jung J, Kim JK, Lee SS, Kim GJ. Changes in PTTG1 by human TERT gene expression modulate the self-renewal of placenta-derived mesenchymal stem cells. Cell Tissue Res 2014; 357:145-57. [PMID: 24816985 DOI: 10.1007/s00441-014-1874-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 03/13/2014] [Indexed: 01/01/2023]
Abstract
In addition to their differentiation potential, self-renewal capability is an important characteristic of stem cells. The limited self-renewal activity of mesenchymal stem cells is the greatest obstacle to the application of stem cell therapy in regenerative medicine. The human TERT gene enhances the self-renewal of MSCs, but the mechanism of self-renewal and the interactions among TERT-gene-related molecules remain unknown. The objectives of this study were to generate immortalized MSCs derived from MSCs isolated from placenta (naive) by human TERT gene transfection with the AMAXA gene delivery system, to compare their characteristics, and to investigate whether increased TERT expression affected the pituitary tumor transforming gene (PTTG1; also known as securin), which is involved in chromosome segregation during mitosis. TERT-immortalized cells (TERT+) with a prolonged life span displayed high PTTG1 expression. TERT+ cells also retained the stemness capacity and multipotency of naive cells and displayed high PTTG1 expression. However, down-regulation of PTTG1 by treatment with short interfering RNA induced cell senescence and decreased telomerase activity. Moreover, TERT bound to PTTG1 formed complexes with chaperones such as Ku70 and heat shock protein 90. Thus, placental MSCs immortalized by TERT gene transfection display differentiation potential and exhibit enhanced self-renewal through a balanced interaction of PTTG1 and chaperones. The interaction between TERT and PTTG1 by association of Ku70 might be important for the enhancement of the limited self-renewal activity of MSCs and for understanding the regulatory mechanisms of self-renewal.
Collapse
Affiliation(s)
- Hyun-Jung Lee
- Department of Biomedical Science, CHA University, 606-16 Yeoksam1-dong, Kangnam-Gu, Seoul, 135-097, Republic of Korea
| | | | | | | | | | | |
Collapse
|
22
|
Recurrent SMARCA4 mutations in small cell carcinoma of the ovary. Nat Genet 2014; 46:424-6. [PMID: 24658004 DOI: 10.1038/ng.2922] [Citation(s) in RCA: 246] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 02/18/2014] [Indexed: 12/30/2022]
Abstract
Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT) is a rare, highly aggressive form of ovarian cancer primarily diagnosed in young women. We identified inactivating biallelic SMARCA4 mutations in 100% of the 12 SCCOHT tumors examined. Protein studies confirmed loss of SMARCA4 expression, suggesting a key role for the SWI/SNF chromatin-remodeling complex in SCCOHT.
Collapse
|
23
|
Holik AZ, Krzystyniak J, Young M, Richardson K, Jardé T, Chambon P, Shorning BY, Clarke AR. Brg1 is required for stem cell maintenance in the murine intestinal epithelium in a tissue-specific manner. Stem Cells 2013; 31:2457-66. [PMID: 23922304 DOI: 10.1002/stem.1498] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Accepted: 07/07/2013] [Indexed: 01/08/2023]
Abstract
Brg1 is a chromatin remodeling factor involved in mediation of a plethora of signaling pathways leading to its participation in various physiological processes both during development and in adult tissues. Among other signaling pathways, the Wnt pathway has been proposed to require Brg1 for transactivation of its target genes. Given the pivotal role of the Wnt pathway in the maintenance of normal intestinal homeostasis, we aimed to investigate the effects of Brg1 loss on the intestinal physiology. To this end, we deleted Brg1 in the murine small and large intestinal epithelia using a range of transgenic approaches. Pan-epithelial loss of Brg1 in the small intestine resulted in crypt ablation, while partial Brg1 deficiency led to gradual repopulation of the intestinal mucosa with wild-type cells. In contrast, Brg1 loss in the large intestinal epithelium was compensated by upregulation of Brm. We propose that while Brg1 is dispensable for the survival and function of the progenitor and differentiated cells in the murine intestinal epithelium, it is essential for the maintenance of the stem cell population in a tissue-specific manner.
Collapse
Affiliation(s)
- Aliaksei Z Holik
- Cardiff School of Biosciences, Cardiff University, Cardiff, United Kingdom; Stem Cells and Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | | | | | | | | | | | | | | |
Collapse
|
24
|
Bidwell JP, Alvarez MB, Hood M, Childress P. Functional impairment of bone formation in the pathogenesis of osteoporosis: the bone marrow regenerative competence. Curr Osteoporos Rep 2013; 11:117-25. [PMID: 23471774 DOI: 10.1007/s11914-013-0139-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The skeleton is a high-renewal organ that undergoes ongoing cycles of remodeling. The regenerative bone formation arm ultimately declines in the aging, postmenopausal skeleton, but current therapies do not adequately address this deficit. Bone marrow is the primary source of the skeletal anabolic response and the mesenchymal stem cells (MSCs), which give rise to bone matrix-producing osteoblasts. The identity of these stem cells is emerging, but it now appears that the term 'MSC' has often been misapplied to the bone marrow stromal cell (BMSC), a progeny of the MSC. Nevertheless, the changes in BMSC phenotype associated with age and estrogen depletion likely contribute to the attenuated regenerative competence of the marrow and may reflect alterations in MSC phenotype. Here we summarize current concepts in bone marrow MSC identity, and within this context, review recent observations on changes in bone marrow population dynamics associated with aging and menopause.
Collapse
Affiliation(s)
- Joseph P Bidwell
- Department of Anatomy and Cell Biology, Indiana University School of Medicine (IUSM), Medical Science Bldg 5035, 635 Barnhill Drive, Indianapolis, IN 46202, USA.
| | | | | | | |
Collapse
|
25
|
Khursheed M, Kolla JN, Kotapalli V, Gupta N, Gowrishankar S, Uppin SG, Sastry RA, Koganti S, Sundaram C, Pollack JR, Bashyam MD. ARID1B, a member of the human SWI/SNF chromatin remodeling complex, exhibits tumour-suppressor activities in pancreatic cancer cell lines. Br J Cancer 2013; 108:2056-62. [PMID: 23660946 PMCID: PMC3670478 DOI: 10.1038/bjc.2013.200] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Background: The human ATP-dependent SWItch/sucrose nonfermentable (SWI/SNF) complex functions as a primary chromatin remodeler during ontogeny, as well as in adult life. Several components of the complex have been suggested to function as important regulators of tumorigenesis in various cancers. In the current study, we have characterised a possible tumour suppressor role for the largest subunit of the complex, namely the AT-rich interaction domain 1B (ARID1B). Methods: We performed Azacytidine and Trichostatin A treatments, followed by bisulphite sequencing to determine the possible DNA methylation-induced transcription repression of the gene in pancreatic cancer (PaCa) cell lines. Functional characterisation of effect of ARID1B ectopic expression in MiaPaCa2 PaCa cell line, which harboured ARID1B homozygous deletion, was carried out. Finally, we evaluated ARID1B protein expression in pancreatic tumour samples using immunohistochemistry on a tissue microarray. Results: ARID1B was transcriptionally repressed due to promoter hypermethylation, and ectopic expression severely compromised the ability of MiaPaCa2 cells to form colonies in liquid culture and soft agar. In addition, ARID1B exhibited significantly reduced/loss of expression in PaCa tissue, especially in samples from advanced-stage tumours, when compared with normal pancreas. Conclusion: The results therefore suggest a possible tumour-suppressor function for ARID1B in PaCa, thus adding to the growing list of SWI/SNF components with a similar function. Given the urgent need to design efficient targeted therapies for PaCa, our study assumes significance.
Collapse
Affiliation(s)
- M Khursheed
- Laboratory of Molecular Oncology, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
BRG1 is required for formation of senescence-associated heterochromatin foci induced by oncogenic RAS or BRCA1 loss. Mol Cell Biol 2013; 33:1819-29. [PMID: 23438604 DOI: 10.1128/mcb.01744-12] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Cellular senescence is an important tumor suppression mechanism. We have previously reported that both oncogene-induced dissociation of BRCA1 from chromatin and BRCA1 knockdown itself drive senescence by promoting formation of senescence-associated heterochromatin foci (SAHF). However, the molecular mechanism by which BRCA1 regulates SAHF formation and senescence is unclear. BRG1 is a chromatin-remodeling factor that interacts with BRCA1 and pRB. Here we show that BRG1 is required for SAHF formation and senescence induced by oncogenic RAS or BRCA1 loss. The interaction between BRG1 and BRCA1 is disrupted during senescence. This correlates with an increased level of chromatin-associated BRG1 in senescent cells. BRG1 knockdown suppresses the formation of SAHF and senescence, while it has no effect on BRCA1 chromatin dissociation induced by oncogenic RAS, indicating that BRG1 functions downstream of BRCA1 chromatin dissociation. Furthermore, BRG1 knockdown inhibits SAHF formation and senescence induced by BRCA1 knockdown. Conversely, BRG1 overexpression drives SAHF formation and senescence in a DNA damage-independent manner. This effect depends upon BRG1's chromatin-remodeling activity as well as the interaction between BRG1 and pRB. Indeed, the interaction between BRG1 and pRB is enhanced during senescence. Chromatin immunoprecipitation analysis revealed that BRG1's association with the human CDKN2A and CDKN1A gene promoters was enhanced during senescence induced by oncogenic RAS or BRCA1 knockdown. Consistently, knockdown of pRB, p21(CIP1), and p16(INK4a), but not p53, suppressed SAHF formation induced by BRG1. Together, these studies reveal the molecular underpinning by which BRG1 acts downstream of BRCA1 to promote SAHF formation and senescence.
Collapse
|
27
|
Bell JC, Plank JL, Dombrowski CC, Kowalczykowski SC. Direct imaging of RecA nucleation and growth on single molecules of SSB-coated ssDNA. Nature 2012; 491:274-8. [PMID: 23103864 PMCID: PMC4112059 DOI: 10.1038/nature11598] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 09/20/2012] [Indexed: 01/14/2023]
Abstract
Escherichia coli RecA is the defining member of a ubiquitous class of DNA strand exchange proteins that are essential for homologous recombination, a pathway that maintains genomic integrity by repairing broken DNA1. To function, filaments of RecA must nucleate and grow on single-stranded DNA (ssDNA) in direct competition with ssDNA-binding protein (SSB), which rapidly binds and continuously sequesters ssDNA, kinetically blocking RecA assembly2,3. This dynamic self-assembly on a DNA lattice, in competition with another protein, is unique for the RecA-family relative to other filament-forming proteins such as actin and tubulin. The complexity of this process has hindered our understanding of RecA filament assembly because ensemble measurements cannot reliably distinguish between the nucleation and growth phases, despite extensive and diverse attempts2–5. Previous single-molecule assays have measured nucleation and growth of RecA—and its eukaryotic homolog RAD51—on naked dsDNA and ssDNA6–12; however, the template for RecA self-assembly in vivo is SSB-coated ssDNA3. Using single-molecule microscopy, we directly visualized RecA filament assembly on single molecules of SSB-coated ssDNA, simultaneously measuring nucleation and growth. We establish that a dimer of RecA is required for nucleation, followed by growth of the filament through monomer addition, consistent with the finding that nucleation, but not growth, is modulated by nucleotide and magnesium ion cofactors. Filament growth is bidirectional, albeit faster in the 5′→3′ direction. Both nucleation and growth are repressed at physiological conditions, highlighting the essential role of recombination mediators in potentiating assembly in vivo. We define a two-step kinetic mechanism where RecA nucleates on transiently exposed ssDNA during SSB sliding and/or partial dissociation (i.e., DNA unwrapping) and then grows. We further demonstrate that the recombination mediator protein pair, RecOR, accelerates both RecA nucleation and filament growth, and that introduction of RecF further stimulates RecA nucleation.
Collapse
Affiliation(s)
- Jason C Bell
- Department of Microbiology, University of California, Davis, California 95616, USA
| | | | | | | |
Collapse
|
28
|
LeBlanc SE, Konda S, Wu Q, Hu YJ, Oslowski CM, Sif S, Imbalzano AN. Protein arginine methyltransferase 5 (Prmt5) promotes gene expression of peroxisome proliferator-activated receptor γ2 (PPARγ2) and its target genes during adipogenesis. Mol Endocrinol 2012; 26:583-97. [PMID: 22361822 DOI: 10.1210/me.2011-1162] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Regulation of adipose tissue formation by adipogenic-regulatory proteins has long been a topic of interest given the ever-increasing health concerns of obesity and type 2 diabetes in the general population. Differentiation of precursor cells into adipocytes involves a complex network of cofactors that facilitate the functions of transcriptional regulators from the CCATT/enhancer binding protein, and the peroxisome proliferator-activated receptor (PPAR) families. Many of these cofactors are enzymes that modulate the structure of chromatin by altering histone-DNA contacts in an ATP-dependent manner or by posttranslationally modifying the histone proteins. Here we report that inhibition of protein arginine methyltransferase 5 (Prmt5) expression in multiple cell culture models for adipogenesis prevented the activation of adipogenic genes. In contrast, overexpression of Prmt5 enhanced adipogenic gene expression and differentiation. Chromatin immunoprecipitation experiments indicated that Prmt5 binds to and dimethylates histones at adipogenic promoters. Furthermore, the presence of Prmt5 promoted the binding of ATP-dependent chromatin-remodeling enzymes and was required for the binding of PPARγ2 at PPARγ2-regulated promoters. The data indicate that Prmt5 acts as a coactivator for the activation of adipogenic gene expression and promotes adipogenic differentiation.
Collapse
Affiliation(s)
- Scott E LeBlanc
- Department of Cell Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | | | | | | | | | | | | |
Collapse
|
29
|
Alessio N, Squillaro T, Cipollaro M, Bagella L, Giordano A, Galderisi U. The BRG1 ATPase of chromatin remodeling complexes is involved in modulation of mesenchymal stem cell senescence through RB-P53 pathways. Oncogene 2010; 29:5452-63. [PMID: 20697355 DOI: 10.1038/onc.2010.285] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We focused our attention on brahma-related gene 1 (BRG1), the ATPase subunit of the SWItch/Sucrose NonFermentable (SWI/SNF) chromatin remodeling complex, and analyzed its role in mesenchymal stem cell (MSC) biology. We hypothesized that deviation from the correct concentration of these proteins, which act at the highest level of gene regulation, may be deleterious for cells. We wanted to know what would happen if a cell had to cope with altered regulation of gene expression, either by upregulation or downregulation of BRG1. We assumed that cells would try to restore homeostasis or, alternatively, that the event could trigger senescence/apoptosis phenomena. To this end, in MSCs, we silenced BRG1gene. Knockdown of BRG1 expression induced a significant increase in senescent cells and decrease in apoptotic cells. It is interesting that BRG1 downregulation also induced an increase in heterochromatin. At the molecular level, these phenomena were associated with activation of retinoblastoma-like protein 2 (RB2)/P130- and P53-related pathways. Senescence was accompanied by reduced expression of some stemness-related genes. This is consistent with our previous research, which showed that BRG1 upregulation by ectopic expression also induced senescence processes. Together, these data suggest that BRG1 belongs to a class of genes whose expression is tightly regulated; hence, subtle alterations in BRG1 activity seem to negatively affect mechanisms regulating chromatin status and, in turn, impair cellular physiology.
Collapse
Affiliation(s)
- N Alessio
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, Temple University, Philadelphia, PA, USA
| | | | | | | | | | | |
Collapse
|
30
|
Yamada T, Akamatsu H, Hasegawa S, Yamamoto N, Yoshimura T, Hasebe Y, Inoue Y, Mizutani H, Uzawa T, Matsunaga K, Nakata S. Age-related changes of p75 neurotrophin receptor-positive adipose-derived stem cells. J Dermatol Sci 2010; 58:36-42. [PMID: 20194005 DOI: 10.1016/j.jdermsci.2010.02.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Revised: 01/18/2010] [Accepted: 02/07/2010] [Indexed: 12/23/2022]
Abstract
BACKGROUND The existence of multipotent stem cells in subcutaneous adipose tissue has been reported. We previously confirmed that p75 neurotrophin receptor (p75NTR; CD271)-positive cells in subcutaneous adipose tissue possessed multipotency, although changes of the characteristics in p75NTR-positive adipose-derived stem cells (ASCs) with aging remain unclear. OBJECTIVE To investigate the effect of aging on p75NTR-positive ASCs. METHODS The number of p75NTR-positive ASCs in subcutaneous adipose tissue of ICR mice aged 3-24 weeks was analyzed by immunostaining and flow cytometry. Subsequently, the cells were isolated and their ability to attach to the cell culture dish, proliferation rate (doubling time) and the expression of senescence-associated beta-galactosidase (SA-beta gal), a cellular senescence marker, were assessed. Age-related changes in the differentiation potential of p75NTR-positive cells in adipogenic, osteogenic, chondrogenic and myogenic lineage were also investigated. RESULTS The number of ASCs per unit of tissue weight in adipose tissue and the attachment rate of isolated cells decreased with aging. No difference in the cell proliferation rate and the percentage of SA-beta gal-positive cells was detected. Although the efficacy of differentiation into adipogenic and osteogenic lineages slightly decreased with aging, the differentiation potential into chondrogenic and myogenic lineages was not changed. CONCLUSION The number of ASCs per unit of tissue weight decreased in aged mice. However, the cells possessed proliferation and differentiation potentials almost equal to those of young mice even though the differentiation potentials showed a tendency of decrease. These results raise the possibility that stem cell functions, self-renewal and multipotency, are maintained regardless of aging.
Collapse
Affiliation(s)
- Takaaki Yamada
- Research Laboratories, Nippon Menard Cosmetic Co., Ltd., 2-7 Torimicho, Nishi-Ku, Nagoya, Aichi 451-0071, Japan.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Squillaro T, Alessio N, Cipollaro M, Renieri A, Giordano A, Galderisi U. Partial silencing of methyl cytosine protein binding 2 (
MECP2
) in mesenchymal stem cells induces senescence with an increase in damaged DNA. FASEB J 2010; 24:1593-603. [DOI: 10.1096/fj.09-143057] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Tiziana Squillaro
- Sbarro Institute for Cancer Research and Molecular MedicineCenter for BiotechnologyTemple UniversityPhiladelphiaPennsylvaniaUSA
| | - Nicola Alessio
- Sbarro Institute for Cancer Research and Molecular MedicineCenter for BiotechnologyTemple UniversityPhiladelphiaPennsylvaniaUSA
| | - Marilena Cipollaro
- Department of Experimental MedicineBiotechnology and Molecular Biology SectionSecond University of NaplesNaplesItaly
| | | | - Antonio Giordano
- Sbarro Institute for Cancer Research and Molecular MedicineCenter for BiotechnologyTemple UniversityPhiladelphiaPennsylvaniaUSA
- Department of Human PathologyOncology University of SienaSiennaItaly
- Human Health FoundationSpoletoItaly
| | - Umberto Galderisi
- Sbarro Institute for Cancer Research and Molecular MedicineCenter for BiotechnologyTemple UniversityPhiladelphiaPennsylvaniaUSA
| |
Collapse
|
32
|
The SWI/SNF chromatin remodeling subunit BRG1 is a critical regulator of p53 necessary for proliferation of malignant cells. Oncogene 2009; 28:2492-501. [PMID: 19448667 PMCID: PMC2708319 DOI: 10.1038/onc.2009.121] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The tumor suppressor p53 preserves genome integrity by inducing transcription of genes controlling growth arrest or apoptosis. Transcriptional activation involves nucleosomal perturbation by chromatin remodeling enzymes. Mammalian SWI/SNF remodeling complexes incorporate either BRG1 or Brm as the ATPase subunit. The observation that tumor cell lines harboring wild-type p53 specifically maintain expression of BRG1 and that BRG1 complexes with p53 prompted us to examine the role of BRG1 in regulation of p53. Remarkably, RNAi depletion of BRG1 but not Brm led to activation of endogenous wild-type p53 and cell senescence. We found a proline rich region (PRR) unique to BRG1 was required for binding to the histone acetyl transferase (HAT) protein CBP as well as to p53. Ectopic expression of a PRR deletion mutant BRG1 that is defective for CBP binding inhibited p53 destabilization. Importantly, RNAi knockdown of BRG1 and CBP reduced p53 poly-ubiquitination in vivo. In support of p53 inactivation by the combined activities of BRG1 and CBP, we show that DNA damage signals promoted disassociation of BRG1 from CBP thereby allowing p53 accumulation. Our data demonstrate a novel function of the evolutionarily conserved chromatin remodeling subunit BRG1, which cooperates with CBP to constrain p53 activity and permit cancer cell proliferation.
Collapse
|
33
|
Ay N, Irmler K, Fischer A, Uhlemann R, Reuter G, Humbeck K. Epigenetic programming via histone methylation at WRKY53 controls leaf senescence in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 58:333-346. [PMID: 19143996 DOI: 10.1111/j.0960-7412.2009.03782.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Leaf senescence, the final step of leaf development, involves extensive reprogramming of gene expression. Here, we show that these processes include discrete changes of epigenetic indexing, as well as global alterations in chromatin organization. During leaf senescence, the interphase nuclei show a decondensation of chromocenter heterochromatin, and changes in the nuclear distribution of the H3K4me2, H3K4me3, and the H3K27me2 and H3K27me3 histone modification marks that index active and inactive chromatin, respectively. Locus-specific epigenetic indexing was studied at the WRKY53 key regulator of leaf senescence. During senescence, when the locus becomes activated, H3K4me2 and H3K4me3 are significantly increased at the 5' end and at coding regions. Impairment of these processes is observed in plants overexpressing the SUVH2 histone methyltransferase, which causes ectopic heterochromatization. In these plants the transcriptional initiation of WRKY53 and of the senescence-associated genes SIRK, SAG101, ANAC083, SAG12 and SAG24 is inhibited, resulting in a delay of leaf senescence. In SUVH2 overexpression plants, significant levels of H3K27me2 and H3K27me3 are detected at the 5'-end region of WRKY53, resulting in its transcriptional repression. Furthermore, SUVH2 overexpression inhibits senescence-associated global changes in chromatin organization. Our data suggest that complex epigenetic processes control the senescence-specific gene expression pattern.
Collapse
Affiliation(s)
- Nicole Ay
- Department of Plant Physiology, Institute of Biology, Martin-Luther University Halle-Wittenberg, Weinbergweg 10, D-06120 Halle, Germany
| | | | | | | | | | | |
Collapse
|
34
|
Becker TM, Haferkamp S, Dijkstra MK, Scurr LL, Frausto M, Diefenbach E, Scolyer RA, Reisman DN, Mann GJ, Kefford RF, Rizos H. The chromatin remodelling factor BRG1 is a novel binding partner of the tumor suppressor p16INK4a. Mol Cancer 2009; 8:4. [PMID: 19149898 PMCID: PMC2644676 DOI: 10.1186/1476-4598-8-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2008] [Accepted: 01/16/2009] [Indexed: 12/15/2022] Open
Abstract
Background CDKN2A/p16INK4a is frequently altered in human cancers and it is the most important melanoma susceptibility gene identified to date. p16INK4a inhibits pRb phosphorylation and induces cell cycle arrest, which is considered its main tumour suppressor function. Nevertheless, additional activities may contribute to the tumour suppressor role of p16INK4a and could help explain its specific association with melanoma predisposition. To identify such functions we conducted a yeast-two-hybrid screen for novel p16INK4a binding partners. Results We now report that p16INK4a interacts with the chromatin remodelling factor BRG1. We investigated the cooperative roles of p16INK4a and BRG1 using a panel of cell lines and a melanoma cell model with inducible p16INK4a expression and BRG1 silencing. We found evidence that BRG1 is not required for p16INK4a-induced cell cycle inhibition and propose that the p16INK4a-BRG1 complex regulates BRG1 chromatin remodelling activity. Importantly, we found frequent loss of BRG1 expression in primary and metastatic melanomas, implicating this novel p16INK4a binding partner as an important tumour suppressor in melanoma. Conclusion This data adds to the increasing evidence implicating the SWI/SNF chromatin remodelling complex in tumour development and the association of p16INK4a with chromatin remodelling highlights potentially new functions that may be important in melanoma predisposition and chemoresistance.
Collapse
Affiliation(s)
- Therese M Becker
- Westmead Institute for Cancer Research, University of Sydney, Westmead Millennium Institute and Westmead Hospital, Australia.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Meagher RB, Kandasamy MK, McKinney EC, Roy E. Chapter 5. Nuclear actin-related proteins in epigenetic control. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2009; 277:157-215. [PMID: 19766970 PMCID: PMC2800988 DOI: 10.1016/s1937-6448(09)77005-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The nuclear actin-related proteins (ARPs) share overall structure and low-level sequence homology with conventional actin. They are indispensable subunits of macromolecular machines that control chromatin remodeling and modification leading to dynamic changes in DNA structure, transcription, and DNA repair. Cellular, genetic, and biochemical studies suggest that the nuclear ARPs are essential to the epigenetic control of the cell cycle and cell proliferation in all eukaryotes, while in plants and animals they also exert epigenetic controls over most stages of multicellular development including organ initiation, the switch to reproductive development, and senescence and programmed cell death. A theme emerging from plants and animals is that in addition to their role in controlling the general compaction of DNA and gene silencing, isoforms of nuclear ARP-containing chromatin complexes have evolved to exert dynamic epigenetic control over gene expression and different phases of multicellular development. Herein, we explore this theme by examining nuclear ARP phylogeny, activities of ARP-containing chromatin remodeling complexes that lead to epigenetic control, expanding developmental roles assigned to several animal and plant ARP-containing complexes, the evidence that thousands of ARP complex isoforms may have evolved in concert with multicellular development, and ARPs in human disease.
Collapse
Affiliation(s)
- Richard B Meagher
- Department of Genetics, Davison Life Sciences Building, University of Georgia, Athens, GA 30602, USA
| | | | | | | |
Collapse
|
36
|
Controversial issue: is it safe to employ mesenchymal stem cells in cell-based therapies? Exp Gerontol 2008; 43:1018-23. [PMID: 18694815 DOI: 10.1016/j.exger.2008.07.004] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Revised: 07/11/2008] [Accepted: 07/15/2008] [Indexed: 12/18/2022]
Abstract
The prospective clinical use of multipotent mesenchymal stromal stem cells (MSC) holds enormous promise for the treatment of a large number of degenerative and age-related diseases. However, the challenges and risks for cell-based therapies are multifaceted. The risks for patients receiving stem cells, which have been expanded in vitro in the presence of xenogenic compounds, can hardly be anticipated and methods for the culture and manipulation of "safe" MSC ex vivo are being investigated. During in vitro expansion, stem cells experience a long replicative history and are thus subject to damage from intracellular and extracellular influences. While murine MSC are prone to cellular transformation in culture, human MSC do not transform. One reason for this striking difference is that during long-term culture, human MSC finally become replicatively senescent. In consequence, this greatly restricts their proliferation and differentiation efficiency. It however also limits the yield of sufficient numbers of cells needed for therapy. Another issue is to eliminate contamination of expanding cells with serum-bound pathogenic agents in order to reduce the risks for infection. A recent technical advancement, which applies human serum platelet lysates as an alternative source for growth factors and essential supplements, allows the unimpaired proliferation of MSC in the absence of animal sera. Here, we present an update regarding cellular senescence of MSC and recent insights concerning potential risks associated with their clinical use.
Collapse
|
37
|
Lepperdinger G, Brunauer R, Gassner R, Jamnig A, Kloss F, Laschober GT. Changes of the Functional Capacity of Mesenchymal Stem Cells due to Aging or Age-Associated Disease - Implications for Clinical Applications and Donor Recruitment. ACTA ACUST UNITED AC 2008; 35:299-305. [PMID: 21512646 DOI: 10.1159/000142373] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2008] [Accepted: 06/26/2008] [Indexed: 12/11/2022]
Abstract
SUMMARY: In contrast to stem cells of embryonic origin, autologous tissue-specific stem cells are easier to introduce into the clinical practice. In this context, molecular and cellular changes, which alter tissue-specific stem cell properties with age, are of particular interest since elderly patients represent the main target group for cell-based therapies. The clinical use of mesenchymal stem cells is an emerging field, especially because this stem cell type appears to be amenable for the treatment of a large number of diseases, such as non-healing bone defects and fractures, inflammatory relief during arthritis, and the repair of suspensory ligament tears. More than that, mesenchymal stem cells provoke effective immune suppression in the context of graft-versus-host disease. Here, we present a comprehensive overview of the recent findings with special attention to age-related changes of mesenchymal stem cell properties and the consequential impact on tissue regeneration and repair, together with the current perception concerning their therapeutic application potential as well as the challenges associated with their clinical use.
Collapse
Affiliation(s)
- Günter Lepperdinger
- Institute for Biomedical Aging Research, Austrian Academy of Sciences, University Hospital Innsbruck, Innsbruck, Austria
| | | | | | | | | | | |
Collapse
|
38
|
Kilbey A, Terry A, Cameron ER, Neil JC. Oncogene-induced senescence: an essential role for Runx. Cell Cycle 2008; 7:2333-40. [PMID: 18677118 DOI: 10.4161/cc.6368] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Anna Kilbey
- Molecular Oncology Laboratory, Institute of Comparative Medicine, Faculty of Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom.
| | | | | | | |
Collapse
|
39
|
Yan Z, Wang Z, Sharova L, Sharov AA, Ling C, Piao Y, Aiba K, Matoba R, Wang W, Ko MS. BAF250B-associated SWI/SNF chromatin-remodeling complex is required to maintain undifferentiated mouse embryonic stem cells. Stem Cells 2008; 26:1155-65. [PMID: 18323406 PMCID: PMC2409195 DOI: 10.1634/stemcells.2007-0846] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Whether SWI/SNF chromatin remodeling complexes play roles in embryonic stem (ES) cells remains unknown. Here we show that SWI/SNF complexes are present in mouse ES cells, and their composition is dynamically regulated upon induction of ES cell differentiation. For example, the SWI/SNF purified from undifferentiated ES cells contains a high level of BAF155 and a low level of BAF170 (both of which are homologs of yeast SWI3 protein), whereas that from differentiated cells contains nearly equal amounts of both. Moreover, the levels of BAF250A and BAF250B decrease during the differentiation of ES cells, whereas that of BRM increases. The altered expression of SWI/SNF components hinted that these complexes could play roles in ES cell maintenance or differentiation. We therefore generated ES cells with biallelic inactivation of BAF250B and found that these cells display a reduced proliferation rate and an abnormal cell cycle. Importantly, these cells are deficient in the self-renewal capacity of undifferentiated ES cells and exhibit certain phenotypes of differentiated cells, including reduced expression of several pluripotency-related genes and increased expression of some differentiation-related genes. These data suggest that the BAF250B-associated SWI/SNF is essential for mouse ES cells to maintain their normal proliferation and pluripotency. The work presented here underscores the importance of SWI/SNF chromatin remodeling complexes in pluripotent stem cells.
Collapse
Affiliation(s)
- Zhijiang Yan
- Genome Instability and Chromatin-Remodeling Section, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224
| | - Zhong Wang
- Cardiovascular Research Center, Massachusetts General Hospital, Richard B. Simches Research Center, Harvard Medical School, Boston, MA 02114
| | - Lioudmila Sharova
- Developmental Genomics and Aging Section, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224
| | - Alexei A. Sharov
- Developmental Genomics and Aging Section, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224
| | - Chen Ling
- Genome Instability and Chromatin-Remodeling Section, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224
| | - Yulan Piao
- Developmental Genomics and Aging Section, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224
| | - Kazuhiro Aiba
- Developmental Genomics and Aging Section, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224
| | - Ryo Matoba
- Developmental Genomics and Aging Section, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224
| | - Weidong Wang
- Genome Instability and Chromatin-Remodeling Section, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224
| | - Minoru S.H. Ko
- Developmental Genomics and Aging Section, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224
| |
Collapse
|
40
|
Chromatin remodelling and actin organisation. FEBS Lett 2008; 582:2041-50. [PMID: 18442483 DOI: 10.1016/j.febslet.2008.04.032] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 04/15/2008] [Accepted: 04/21/2008] [Indexed: 11/22/2022]
Abstract
Chromatin remodelling is a prerequisite for nuclear processes, and cells have several different ways of remodelling the chromatin structure. The ATP-dependent chromatin remodelling complexes are large multiprotein complexes that use ATP to change DNA-histone contacts. These complexes are classified into 4 sub-families depending on the central ATPase. The switch mating type/sucrose non-fermenting (SWI/SNF) complexes are mainly involved in transcriptional regulation, and this means that they are involved in many processes, such as the formation of actin filaments in the cytoplasm. SWI/SNF complexes are involved in the regulation of genes expressing cell adhesion proteins and extracellular matrix proteins. Actin is also present in the nucleus, affecting transcription, RNA processing and export. In addition, actin and actin-related proteins are subunits of SWI/SNF complexes and the INO80-containing complexes, another subfamily of ATP-dependent chromatin remodelling complexes. Not all functions of the actin and actin-related proteins in the complexes are yet clear: it is known that they play important roles in maintaining the stability of the proteins, possibly by bridging subunits and recruiting the complexes to chromatin.
Collapse
|