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Davidson RK, Wu W, Kanojia S, George RM, Huter K, Sandoval K, Osmulski M, Casey N, Spaeth JM. The SWI/SNF chromatin remodelling complex regulates pancreatic endocrine cell expansion and differentiation in mice in vivo. Diabetologia 2024:10.1007/s00125-024-06211-7. [PMID: 38958700 DOI: 10.1007/s00125-024-06211-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 05/16/2024] [Indexed: 07/04/2024]
Abstract
AIMS/HYPOTHESIS Strategies to augment functional beta cell mass include directed differentiation of stem cells towards a beta cell fate, which requires extensive knowledge of transcriptional programs governing endocrine progenitor cell differentiation in vivo. We aimed to study the contributions of the Brahma-related gene-1 (BRG1) and Brahma (BRM) ATPase subunits of the SWI/SNF chromatin remodelling complex to endocrine cell development. METHODS We generated mice with endocrine progenitor-specific Neurog3-Cre BRG1 removal in the presence of heterozygous (Brg1Δendo;Brm+/-) or homozygous (double knockout: DKOΔendo) BRM deficiency. Whole-body metabolic phenotyping, islet function characterisation, islet quantitative PCR and histological characterisation were performed on animals and tissues postnatally. To test the mechanistic actions of SWI/SNF in controlling gene expression during endocrine cell development, single-cell RNA-seq was performed on flow-sorted endocrine-committed cells from embryonic day 15.5 control and mutant embryos. RESULTS Brg1Δendo;Brm+/- mice exhibit severe glucose intolerance, hyperglycaemia and hypoinsulinaemia, resulting, in part, from reduced islet number; diminished alpha, beta and delta cell mass; compromised islet insulin secretion; and altered islet gene expression programs, including reductions in MAFA and urocortin 3 (UCN3). DKOΔendo mice were not recovered at weaning; however, postnatal day 6 DKOΔendo mice were severely hyperglycaemic with reduced serum insulin levels and beta cell area. Single-cell RNA-seq of embryonic day 15.5 lineage-labelled cells revealed endocrine progenitor, alpha and beta cell populations from SWI/SNF mutants have reduced expression of Mafa, Gcg, Ins1 and Ins2, suggesting limited differentiation capacity. Reduced Neurog3 transcripts were discovered in DKOΔendo endocrine progenitor clusters, and the proliferative capacity of neurogenin 3 (NEUROG3)+ cells was reduced in Brg1Δendo;Brm+/- and DKOΔendo mutants. CONCLUSIONS/INTERPRETATION Loss of BRG1 from developing endocrine progenitor cells has a severe postnatal impact on glucose homeostasis, and loss of both subunits impedes animal survival, with both groups exhibiting alterations in hormone transcripts embryonically. Taken together, these data highlight the critical role SWI/SNF plays in governing gene expression programs essential for endocrine cell development and expansion. DATA AVAILABILITY Raw and processed data for scRNA-seq have been deposited into the NCBI Gene Expression Omnibus (GEO) database under the accession number GSE248369.
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Grants
- CA082709 Division of Cancer Prevention, National Cancer Institute
- DK097512 Division of Diabetes, Endocrinology, and Metabolic Diseases
- DK097771 Division of Diabetes, Endocrinology, and Metabolic Diseases
- DK106846 Division of Diabetes, Endocrinology, and Metabolic Diseases
- DK115633 Division of Diabetes, Endocrinology, and Metabolic Diseases
- DK127129 Division of Diabetes, Endocrinology, and Metabolic Diseases
- DK128918 Division of Diabetes, Endocrinology, and Metabolic Diseases
- DK129287 Division of Diabetes, Endocrinology, and Metabolic Diseases
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Affiliation(s)
- Rebecca K Davidson
- Center for Diabetes & Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Wenting Wu
- Center for Diabetes & Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Sukrati Kanojia
- Center for Diabetes & Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Rajani M George
- Center for Diabetes & Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kayla Huter
- Center for Diabetes & Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kassandra Sandoval
- Center for Diabetes & Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Meredith Osmulski
- Center for Diabetes & Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Nolan Casey
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jason M Spaeth
- Center for Diabetes & Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA.
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA.
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA.
- Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA.
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Wang Y, Meraz IM, Qudratullah M, Kotagiri S, Han Y, Xi Y, Wang J, Lissanu Y. SMARCA4 mutation induces tumor cell-intrinsic defects in enhancer landscape and resistance to immunotherapy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.18.599431. [PMID: 38948751 PMCID: PMC11212967 DOI: 10.1101/2024.06.18.599431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Cancer genomic studies have identified frequent alterations in components of the SWI/SNF (SWItch/Sucrose Non- Fermenting) chromatin remodeling complex including SMARCA4 and ARID1A . Importantly, clinical reports indicate that SMARCA4 -mutant lung cancers respond poorly to immunotherapy and have dismal prognosis. However, the mechanistic basis of immunotherapy resistance is unknown. Here, we corroborated the clinical findings by using immune-humanized, syngeneic, and genetically engineered mouse models of lung cancer harboring SMARCA4 deficiency. Specifically, we show that SMARCA4 loss caused decreased response to anti-PD1 immunotherapy associated with significantly reduced infiltration of dendritic cells (DCs) and CD4+ T cells into the tumor microenvironment (TME). Mechanistically, we show that SMARCA4 loss in tumor cells led to profound downregulation of STING, IL1β and other components of the innate immune system as well as inflammatory cytokines that are required for efficient recruitment and activity of immune cells. We establish that this deregulation of gene expression is caused by cancer cell-intrinsic reprogramming of the enhancer landscape with marked loss of chromatin accessibility at enhancers of genes involved in innate immune response such as STING, IL1β, type I IFN and inflammatory cytokines. Interestingly, we observed that transcription factor NF-κB binding motif was highly enriched in enhancers that lose accessibility upon SMARCA4 deficiency. Finally, we confirmed that SMARCA4 and NF-κB co-occupy the same genomic loci on enhancers associated with STING and IL1β, indicating a functional interplay between SMARCA4 and NF-κB. Taken together, our findings provide the mechanistic basis for the poor response of SMARCA4 -mutant tumors to anti-PD1 immunotherapy and establish a functional link between SMARCA4 and NF-κB on innate immune and inflammatory gene expression regulation.
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Gamble N, Bradu A, Caldwell JA, McKeever J, Bolonduro O, Ermis E, Kaiser C, Kim Y, Parks B, Klemm S, Greenleaf WJ, Crabtree GR, Koh AS. PU.1 and BCL11B sequentially cooperate with RUNX1 to anchor mSWI/SNF to poise the T cell effector landscape. Nat Immunol 2024; 25:860-872. [PMID: 38632339 PMCID: PMC11089574 DOI: 10.1038/s41590-024-01807-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 03/11/2024] [Indexed: 04/19/2024]
Abstract
Adaptive immunity relies on specialized effector functions elicited by lymphocytes, yet how antigen recognition activates appropriate effector responses through nonspecific signaling intermediates is unclear. Here we examined the role of chromatin priming in specifying the functional outputs of effector T cells and found that most of the cis-regulatory landscape active in effector T cells was poised early in development before the expression of the T cell antigen receptor. We identified two principal mechanisms underpinning this poised landscape: the recruitment of the nucleosome remodeler mammalian SWItch/Sucrose Non-Fermentable (mSWI/SNF) by the transcription factors RUNX1 and PU.1 to establish chromatin accessibility at T effector loci; and a 'relay' whereby the transcription factor BCL11B succeeded PU.1 to maintain occupancy of the chromatin remodeling complex mSWI/SNF together with RUNX1, after PU.1 silencing during lineage commitment. These mechanisms define modes by which T cells acquire the potential to elicit specialized effector functions early in their ontogeny and underscore the importance of integrating extrinsic cues to the developmentally specified intrinsic program.
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Affiliation(s)
- Noah Gamble
- Department of Pathology, University of Chicago, Chicago, IL, USA
- Graduate Program in Biophysical Sciences, University of Chicago, Chicago, IL, USA
| | - Alexandra Bradu
- Department of Pathology, University of Chicago, Chicago, IL, USA
| | - Jason A Caldwell
- Department of Pathology, University of Chicago, Chicago, IL, USA
| | - Joshua McKeever
- Department of Pathology, University of Chicago, Chicago, IL, USA
- Committee on Molecular Metabolism and Nutrition, University of Chicago, Chicago, IL, USA
| | - Olubusayo Bolonduro
- Department of Pathology, University of Chicago, Chicago, IL, USA
- Committee on Genetics, Genomics, Systems Biology, University of Chicago, Chicago, IL, USA
| | - Ebru Ermis
- Department of Pathology, University of Chicago, Chicago, IL, USA
| | - Caroline Kaiser
- Department of Pathology, University of Chicago, Chicago, IL, USA
- Department of Human Genetics, University of Chicago, Chicago, IL, USA
| | - YeEun Kim
- Immunology Program, Stanford University, Stanford, CA, USA
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Benjamin Parks
- Department of Genetics, Stanford University, Stanford, CA, USA
- Department of Computer Science, Stanford University, Stanford, CA, USA
| | - Sandy Klemm
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - William J Greenleaf
- Department of Computer Science, Stanford University, Stanford, CA, USA
- Department of Applied Physics, Stanford University, Stanford, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Gerald R Crabtree
- Department of Pathology, Stanford University, Stanford, CA, USA
- Department of Developmental Biology, Stanford University, Stanford, CA, USA
| | - Andrew S Koh
- Department of Pathology, University of Chicago, Chicago, IL, USA.
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA.
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Göbel C, Schoof M, Holdhof D, Spohn M, Schüller U. SMARCA4 Loss and Mutated β-Catenin Induce Proliferative Lesions in the Murine Embryonic Cerebellum. J Neurosci 2024; 44:e1605232024. [PMID: 38383496 PMCID: PMC11007475 DOI: 10.1523/jneurosci.1605-23.2024] [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: 08/24/2023] [Revised: 01/26/2024] [Accepted: 01/31/2024] [Indexed: 02/23/2024] Open
Abstract
Almost all medulloblastomas (MB) of the Wingless/Int-1 (WNT) type are characterized by hotspot mutations in CTNNB1, and mouse models have convincingly demonstrated the tumor-initiating role of these mutations. Additional alterations in SMARCA4 are detected in ∼20% of WNT MB, but their functional role is mostly unknown. We, therefore, amended previously described brain lipid binding protein (Blbp)-cre::Ctnnb1(ex3)fl/wt mice by the introduction of floxed Smarca4 alleles. Unexpectedly, mutated and thereby stabilized β-catenin on its own induced severe developmental phenotypes in male and female Blbp-cre::Ctnnb1(ex3)fl/wt mice in our hands, including a thinned cerebral cortex, hydrocephalus, missing cerebellar layering, and cell accumulations in the brainstem and cerebellum. An additional loss of SMARCA4 even resulted in prenatal death for most mice. Respective Blbp-cre::Ctnnb1(ex3)fl/wt::Smarca4fl/rec mutants (male and female) developed large proliferative lesions in the cerebellum evolving from E13.5 to E16.5. Histological and molecular analysis of these lesions by DNA methylation profiling and single-cell RNA sequencing suggested an origin in early undifferentiated SOX2-positive cerebellar progenitors. Furthermore, upregulated WNT signaling, altered actin/cytoskeleton organization, and reduced neuronal differentiation were evident in mutant cells. In vitro, cells harboring alterations in both Ctnnb1 and Smarca4 were negatively selected and did not show tumorigenic potential after transplantation in adult female recipient mice. However, in cerebellar explant cultures, mutant cells displayed significantly increased proliferation, suggesting an important role of the embryonic microenvironment in the development of lesions. Altogether, these results represent an important first step toward the unraveling of tumorigenic mechanisms induced by aberrant WNT signaling and SMARCA4 deficiency.
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Affiliation(s)
- Carolin Göbel
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg D-20251, Germany
- Research Institute Children's Cancer Center Hamburg, Hamburg D-20251, Germany
| | - Melanie Schoof
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg D-20251, Germany
- Research Institute Children's Cancer Center Hamburg, Hamburg D-20251, Germany
| | - Dörthe Holdhof
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg D-20251, Germany
- Research Institute Children's Cancer Center Hamburg, Hamburg D-20251, Germany
| | - Michael Spohn
- Research Institute Children's Cancer Center Hamburg, Hamburg D-20251, Germany
- Bioinformatics Core, University Medical Center Hamburg-Eppendorf, Hamburg D-20251, Germany
| | - Ulrich Schüller
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg D-20251, Germany
- Research Institute Children's Cancer Center Hamburg, Hamburg D-20251, Germany
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg D-20251, Germany
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5
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Göbel C, Godbole S, Schoof M, Holdhof D, Kresbach C, Loose C, Neumann J, Schüller U. MYC overexpression and SMARCA4 loss cooperate to drive medulloblastoma formation in mice. Acta Neuropathol Commun 2023; 11:174. [PMID: 37919824 PMCID: PMC10621315 DOI: 10.1186/s40478-023-01654-2] [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: 07/12/2023] [Accepted: 09/17/2023] [Indexed: 11/04/2023] Open
Abstract
Group 3 medulloblastoma is one of the most aggressive types of childhood brain tumors. Roughly 30% of cases carry genetic alterations in MYC, SMARCA4, or both genes combined. While overexpression of MYC has previously been shown to drive medulloblastoma formation in mice, the functional significance of SMARCA4 mutations and their suitability as a therapeutic target remain largely unclear. To address this issue, we combined overexpression of MYC with a loss of SMARCA4 in granule cell precursors. Both alterations did not increase proliferation of granule cell precursors in vitro. However, combined MYC overexpression and SMARCA4 loss successfully induced tumor formation in vivo after orthotopic transplantation in recipient mice. Resulting tumors displayed anaplastic histology and exclusively consisted of SMARCA4-negative cells although a mixture of recombined and non-recombined cells was injected. These observations provide first evidence for a tumor-promoting role of a SMARCA4 deficiency in the development of medulloblastoma. In comparing the transcriptome of tumors to the cells of origin and an established Sonic Hedgehog medulloblastoma model, we gathered first hints on deregulated gene expression that could be specifically involved in SMARCA4/MYC driven tumorigenesis. Finally, an integration of RNA sequencing and DNA methylation data of murine tumors with human samples revealed a high resemblance to human Group 3 medulloblastoma on the molecular level. Altogether, the development of SMARCA4-deficient medulloblastomas in mice paves the way to deciphering the role of frequently occurring SMARCA4 alterations in Group 3 medulloblastoma with the perspective to explore targeted therapeutic options.
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Affiliation(s)
- Carolin Göbel
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, Building N63 (LIV), Hamburg, D-20251, Germany
| | - Shweta Godbole
- Center for Molecular Neurobiology, Falkenried 94, Hamburg, 20251, Germany
| | - Melanie Schoof
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, Building N63 (LIV), Hamburg, D-20251, Germany
| | - Dörthe Holdhof
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, Building N63 (LIV), Hamburg, D-20251, Germany
| | - Catena Kresbach
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, Building N63 (LIV), Hamburg, D-20251, Germany
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany
| | - Carolin Loose
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, Building N63 (LIV), Hamburg, D-20251, Germany
| | - Julia Neumann
- Center for Molecular Neurobiology, Falkenried 94, Hamburg, 20251, Germany
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany
| | - Ulrich Schüller
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany.
- Research Institute Children's Cancer Center Hamburg, Martinistrasse 52, Building N63 (LIV), Hamburg, D-20251, Germany.
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg, 20251, Germany.
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Xu J, Zhou X, Zhang T, Zhang B, Xu PX. Smarca4 deficiency induces Pttg1 oncogene upregulation and hyperproliferation of tubular and interstitial cells during kidney development. Front Cell Dev Biol 2023; 11:1233317. [PMID: 37727504 PMCID: PMC10506413 DOI: 10.3389/fcell.2023.1233317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/17/2023] [Indexed: 09/21/2023] Open
Abstract
Kidney formation and nephrogenesis are controlled by precise spatiotemporal gene expression programs, which are coordinately regulated by cell-cycle, cell type-specific transcription factors and epigenetic/chromatin regulators. However, the roles of epigenetic/chromatin regulators in kidney development and disease remain poorly understood. In this study, we investigated the impact of deleting the chromatin remodeling factor Smarca4 (Brg1), a human Wilms tumor-associated gene, in Wnt4-expressing cells. Smarca4 deficiency led to severe tubular defects and a shortened medulla. Through unbiased single-cell RNA sequencing analyses, we identified multiple types of Wnt4 Cre-labeled interstitial cells, along with nephron-related cells. Smarca4 deficiency increased interstitial cells but markedly reduced tubular cells, resulting in cells with mixed identity and elevated expression of cell-cycle regulators and genes associated with extracellular matrix and epithelial-to-mesenchymal transition/fibrosis. We found that Smarca4 loss induced a significant upregulation of the oncogene Pttg1 and hyperproliferation of Wnt4 Cre-labeled cells. These changes in the cellular state could hinder the cellular transition into characteristic tubular structures, eventually leading to fibrosis. In conclusion, our findings shed light on novel cell types and genes associated with Wnt4 Cre-labeled cells and highlight the critical role of Smarca4 in regulating tubular cell differentiation and the expression of the cancer-causing gene Pttg1 in the kidney. These findings may provide valuable insights into potential therapeutic strategies for renal cell carcinoma resulting from SMARCA4 deficiency.
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Affiliation(s)
- Jinshu Xu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Xianxiao Zhou
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Ting Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Pin-Xian Xu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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7
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Araki O, Tsuda M, Omatsu M, Namikawa M, Sono M, Fukunaga Y, Masuda T, Yoshikawa T, Nagao M, Ogawa S, Masuo K, Goto N, Muta Y, Hiramatsu Y, Maruno T, Nakanishi Y, Koyasu S, Masui T, Hatano E, Saur D, Fukuda A, Seno H. Brg1 controls stemness and metastasis of pancreatic cancer through regulating hypoxia pathway. Oncogene 2023:10.1038/s41388-023-02716-4. [PMID: 37198398 DOI: 10.1038/s41388-023-02716-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 05/01/2023] [Accepted: 05/04/2023] [Indexed: 05/19/2023]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease. We previously reported that chromatin remodeler Brg1 is essential for acinar cell-derived PDAC formation in mice. However, the functional role of Brg1 in established PDAC and its metastasis remains unknown. Here, we investigated the importance of Brg1 for established PDAC by using a mouse model with a dual recombinase system. We discovered that Brg1 was a critical player for the cell survival and growth of spontaneously developed PDAC in mice. In addition, Brg1 was essential for metastasis of PDAC cells by inhibiting apoptosis in splenic injection and peritoneal dissemination models. Moreover, cancer stem-like property was compromised in PDAC cells by Brg1 ablation. Mechanistically, the hypoxia pathway was downregulated in Brg1-deleted mouse PDAC and BRG1-low human PDAC. Brg1 was essential for HIF-1α to bind to its target genes to augment the hypoxia pathway, which was important for PDAC cells to maintain their stem-like properties and to metastasize to the liver. Human PDAC cells with high BRG1 expression were more susceptible to BRG1 suppression. In conclusion, Brg1 plays a critical role for cell survival, stem-like property and metastasis of PDAC through the regulation of hypoxia pathway, and thus could be a novel therapeutic target for PDAC.
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Affiliation(s)
- Osamu Araki
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Motoyuki Tsuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Mayuki Omatsu
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Mio Namikawa
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Makoto Sono
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yuichi Fukunaga
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
- Department of Drug Discovery Medicine, Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tomonori Masuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takaaki Yoshikawa
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Munemasa Nagao
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Satoshi Ogawa
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kenji Masuo
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Norihiro Goto
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yu Muta
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yukiko Hiramatsu
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takahisa Maruno
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yuki Nakanishi
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Sho Koyasu
- Departments of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Toshihiko Masui
- Division of Hepato-Biliary-Pancreatic Surgery and Transplantation, Department of Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Etsuro Hatano
- Division of Hepato-Biliary-Pancreatic Surgery and Transplantation, Department of Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Dieter Saur
- Department of Internal Medicine II, Klinikum rechts der Isar, Technische Universität München, München, Germany
| | - Akihisa Fukuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan.
| | - Hiroshi Seno
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
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8
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Abedini A, Landry DA, Macaulay AD, Vaishnav H, Parbhakar A, Ibrahim D, Salehi R, Maranda V, Macdonald E, Vanderhyden BC. SWI/SNF chromatin remodeling subunit Smarca4/BRG1 is essential for female fertility†. Biol Reprod 2023; 108:279-291. [PMID: 36440965 PMCID: PMC9930400 DOI: 10.1093/biolre/ioac209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 07/21/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022] Open
Abstract
Mammalian folliculogenesis is a complex process that involves the regulation of chromatin structure for gene expression and oocyte meiotic resumption. The SWI/SNF complex is a chromatin remodeler using either Brahma-regulated gene 1 (BRG1) or BRM (encoded by Smarca4 and Smarca2, respectively) as its catalytic subunit. SMARCA4 loss of expression is associated with a rare type of ovarian cancer; however, its function during folliculogenesis remains poorly understood. In this study, we describe the phenotype of BRG1 mutant mice to better understand its role in female fertility. Although no tumor emerged from BRG1 mutant mice, conditional depletion of Brg1 in the granulosa cells (GCs) of Brg1fl/fl;Amhr2-Cre mice caused sterility, whereas conditional depletion of Brg1 in the oocytes of Brg1fl/fl;Gdf9-Cre mice resulted in subfertility. Recovery of cumulus-oocyte complexes after natural mating or superovulation showed no significant difference in the Brg1fl/fl;Amhr2-Cre mutant mice and significantly fewer oocytes in the Brg1fl/fl;Gdf9-Cre mutant mice compared with controls, which may account for the subfertility. Interestingly, the evaluation of oocyte developmental competence by in vitro culture of retrieved two-cell embryos indicated that oocytes originating from the Brg1fl/fl;Amhr2-Cre mice did not reach the blastocyst stage and had higher rates of mitotic defects, including micronuclei. Together, these results indicate that BRG1 plays an important role in female fertility by regulating granulosa and oocyte functions during follicle growth and is needed for the acquisition of oocyte developmental competence.
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Affiliation(s)
- Atefeh Abedini
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - David A Landry
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.,Interdisciplinary School of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Angus D Macaulay
- Chronic Diseases Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Het Vaishnav
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Ashna Parbhakar
- Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Dalia Ibrahim
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Reza Salehi
- Chronic Diseases Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Vincent Maranda
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Elizabeth Macdonald
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Barbara C Vanderhyden
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
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9
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Neyazi S, Altendorf L, Schwetje D, Göbel C, Schoof M, Holdhof D, Schüller U. Generation of new transgenic SMARCA4-deficient mouse models results in neuromuscular weakness and paralysis of limbs. Brain Pathol 2022; 33:e13146. [PMID: 36582072 PMCID: PMC10154361 DOI: 10.1111/bpa.13146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 12/19/2022] [Indexed: 12/31/2022] Open
Affiliation(s)
- Sina Neyazi
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Research Institute Children's Cancer Center Hamburg, Hamburg, Germany.,Department of Pediatric Oncology, Dana-Farber Cancer Institute Boston, Massachusetts, USA
| | - Lea Altendorf
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Research Institute Children's Cancer Center Hamburg, Hamburg, Germany
| | - Dora Schwetje
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Research Institute Children's Cancer Center Hamburg, Hamburg, Germany.,Research Group Anatomy, School of Medicine and Health Studies, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Carolin Göbel
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Research Institute Children's Cancer Center Hamburg, Hamburg, Germany
| | - Melanie Schoof
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Research Institute Children's Cancer Center Hamburg, Hamburg, Germany
| | - Dörthe Holdhof
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Research Institute Children's Cancer Center Hamburg, Hamburg, Germany
| | - Ulrich Schüller
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Research Institute Children's Cancer Center Hamburg, Hamburg, Germany.,Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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10
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de Castro RO, Previato de Almeida L, Carbajal A, Gryniuk I, Pezza RJ. PBAF chromatin remodeler complexes that mediate meiotic transitions in mouse. Development 2022; 149:dev199967. [PMID: 36111709 PMCID: PMC9573785 DOI: 10.1242/dev.199967] [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: 07/06/2021] [Accepted: 08/18/2022] [Indexed: 09/18/2023]
Abstract
Gametogenesis in mammals encompasses highly regulated developmental transitions. These are associated with changes in transcription that cause characteristic patterns of gene expression observed during distinct stages of gamete development, which include specific activities with critical meiotic functions. SWI/SNF chromatin remodelers are recognized regulators of gene transcription and DNA repair, but their composition and functions in meiosis are poorly understood. We have generated gamete-specific conditional knockout mice for ARID2, a specific regulatory subunit of PBAF, and have compared its phenotype with BRG1 knockouts, the catalytic subunit of PBAF/BAF complexes. While Brg1Δ/Δ knockout acts at an early stage of meiosis and causes cell arrest at pachynema, ARID2 activity is apparently required at the end of prophase I. Striking defects in spindle assembly and chromosome-spindle attachment observed in Arid2Δ/Δ knockouts are attributed to an increase in aurora B kinase, a master regulator of chromosome segregation, at centromeres. Further genetic and biochemical analyses suggest the formation of a canonical PBAF and a BRG1-independent complex containing ARID2 and PBRM1 as core components. The data support a model in which different PBAF complexes regulate different stages of meiosis and gametogenesis.
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Affiliation(s)
- Rodrigo O. de Castro
- Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Luciana Previato de Almeida
- Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Agustin Carbajal
- Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Irma Gryniuk
- Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Roberto J. Pezza
- Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
- Department of Cell Biology, University of Oklahoma Health Science Center, Oklahoma City, OK 73104, USA
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11
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Yoshikawa T, Fukuda A, Omatsu M, Namikawa M, Sono M, Yuichi F, Masuda T, Araki O, Nagao M, Ogawa S, Masuo K, Goto N, Hiramatsu Y, Muta Y, Tsuda M, Maruno T, Nakanishi Y, Kawada K, Takaishi S, Seno H. JNK pathway plays a critical role for expansion of human colorectal cancer in the context of BRG1 suppression. Cancer Sci 2022; 113:3417-3427. [PMID: 35924439 PMCID: PMC9530857 DOI: 10.1111/cas.15520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 07/14/2022] [Accepted: 07/26/2022] [Indexed: 12/09/2022] Open
Abstract
Tumor stem cells (TSCs), capable of self‐renewal and continuous production of progeny cells, could be potential therapeutic targets. We have recently reported that chromatin remodeling regulator Brg1 is required for maintenance of murine intestinal TSCs and stemness feature of human colorectal cancer (CRC) cells by inhibiting apoptosis. However, it is still unclear how BRG1 suppression changes the underlying intracellular mechanisms of human CRC cells. We found that Brg1 suppression resulted in upregulation of the JNK signaling pathway in human CRC cells and murine intestinal TSCs. Simultaneous suppression of BRG1 and the JNK pathway, either by pharmacological inhibition or silencing of c‐JUN, resulted in even stronger inhibition of the expansion of human CRC cells compared to Brg1 suppression alone. Consistently, high c‐JUN expression correlated with worse prognosis for survival in human CRC patients with low BRG1 expression. Therefore, the JNK pathway plays a critical role for expansion and stemness of human CRC cells in the context of BRG1 suppression, and thus a combined blockade of BRG1 and the JNK pathway could be a novel therapeutic approach against human CRC.
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Affiliation(s)
- Takaaki Yoshikawa
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Department of Gastroenterology and Hepatology, Kitano Hospital, Tazuke Kofukai Medical Research Institute, Osaka, Japan
| | - Akihisa Fukuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Mayuki Omatsu
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Mio Namikawa
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Makoto Sono
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Fukunaga Yuichi
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Department of Drug Discovery Medicine, Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tomonori Masuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Osamu Araki
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Munemasa Nagao
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Satoshi Ogawa
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kenji Masuo
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Laboratory for Malignancy Control Research (DSK project), Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Norihiro Goto
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yukiko Hiramatsu
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yu Muta
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Motoyuki Tsuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takahisa Maruno
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yuki Nakanishi
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kenji Kawada
- Department of Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Shigeo Takaishi
- Laboratory for Malignancy Control Research (DSK project), Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hiroshi Seno
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
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12
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Jin Y, Gao X, Lu M, Chen G, Yang X, Ren N, Song Y, Hou C, Li J, Liu Q, Gao J. Loss of BAF (mSWI/SNF) chromatin-remodeling ATPase Brg1 causes multiple malformations of cortical development in mice. Hum Mol Genet 2022; 31:3504-3520. [PMID: 35666215 DOI: 10.1093/hmg/ddac127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 05/12/2022] [Accepted: 05/26/2022] [Indexed: 11/13/2022] Open
Abstract
Mutations in genes encoding subunits of the BAF (BRG1/BRM-associated factor) complex cause various neurodevelopmental diseases. However, the underlying pathophysiology remains largely unknown. Here, we analyzed the function of Brg1, a core ATPase of BAF complexes, in the developing cerebral cortex. Loss of Brg1 causes several morphological defects resembling human malformations of cortical development (MCDs), including microcephaly, cortical dysplasia, cobblestone lissencephaly, and periventricular heterotopia. We demonstrated that neural progenitor cell (NPC) renewal, neuronal differentiation, neuronal migration, apoptotic cell death, pial basement membrane, and apical junctional complexes, which are associated with MCD formation, were impaired after Brg1 deletion. Furthermore, transcriptome profiling indicated that a large number of genes were deregulated. The deregulated genes were closely related to MCD formation, and most of these genes were bound by Brg1. Cumulatively, our study indicates an essential role of Brg1 in cortical development and provides a new possible pathogenesis underlying Brg1-based BAF complex-related neurodevelopmental disorders.
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Affiliation(s)
- Yecheng Jin
- Key Laboratory for Experimental Teratology of the Ministry of Education and Department of Medical Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Xiaotong Gao
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, Shandong 250100, China
| | - Miaoqing Lu
- Department of Neurology, Ningbo Medical Center Lihuili Hospital, Ningbo University, Ningbo, Zhejiang 315040, China
| | - Ge Chen
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, Shandong 250100, China
| | - Xiaofan Yang
- Key Laboratory for Experimental Teratology of the Ministry of Education and Department of Medical Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China.,Department of Pediatrics, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Naixia Ren
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, Shandong 250100, China
| | - Yuning Song
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, Shandong 250100, China
| | - Congzhe Hou
- Department of Reproductive medicine, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250033, China
| | - Jiangxia Li
- Key Laboratory for Experimental Teratology of the Ministry of Education and Department of Medical Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Qiji Liu
- Key Laboratory for Experimental Teratology of the Ministry of Education and Department of Medical Genetics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China
| | - Jiangang Gao
- School of Laboratory Animal Science, Shandong First Medical University, Jinan, Shandong 250117, China
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13
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Burda JE, O'Shea TM, Ao Y, Suresh KB, Wang S, Bernstein AM, Chandra A, Deverasetty S, Kawaguchi R, Kim JH, McCallum S, Rogers A, Wahane S, Sofroniew MV. Divergent transcriptional regulation of astrocyte reactivity across disorders. Nature 2022; 606:557-564. [PMID: 35614216 PMCID: PMC10027402 DOI: 10.1038/s41586-022-04739-5] [Citation(s) in RCA: 74] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 04/07/2022] [Indexed: 01/30/2023]
Abstract
Astrocytes respond to injury and disease in the central nervous system with reactive changes that influence the outcome of the disorder1-4. These changes include differentially expressed genes (DEGs) whose contextual diversity and regulation are poorly understood. Here we combined biological and informatic analyses, including RNA sequencing, protein detection, assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) and conditional gene deletion, to predict transcriptional regulators that differentially control more than 12,000 DEGs that are potentially associated with astrocyte reactivity across diverse central nervous system disorders in mice and humans. DEGs associated with astrocyte reactivity exhibited pronounced heterogeneity across disorders. Transcriptional regulators also exhibited disorder-specific differences, but a core group of 61 transcriptional regulators was identified as common across multiple disorders in both species. We show experimentally that DEG diversity is determined by combinatorial, context-specific interactions between transcriptional regulators. Notably, the same reactivity transcriptional regulators can regulate markedly different DEG cohorts in different disorders; changes in the access of transcriptional regulators to DNA-binding motifs differ markedly across disorders; and DEG changes can crucially require multiple reactivity transcriptional regulators. We show that, by modulating reactivity, transcriptional regulators can substantially alter disorder outcome, implicating them as therapeutic targets. We provide searchable resources of disorder-related reactive astrocyte DEGs and their predicted transcriptional regulators. Our findings show that transcriptional changes associated with astrocyte reactivity are highly heterogeneous and are customized from vast numbers of potential DEGs through context-specific combinatorial transcriptional-regulator interactions.
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Affiliation(s)
- Joshua E Burda
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
- Center for Neural Science and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
| | - Timothy M O'Shea
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Yan Ao
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Keshav B Suresh
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
- Center for Neural Science and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Shinong Wang
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Alexander M Bernstein
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Ashu Chandra
- Department of Computer Science, University of California Los Angeles, Los Angeles, CA, USA
| | - Sandeep Deverasetty
- Department of Psychiatry, University of California Los Angeles, Los Angeles, CA, USA
- Department of Neurology, University of California Los Angeles, Los Angeles, CA, USA
| | - Riki Kawaguchi
- Department of Psychiatry, University of California Los Angeles, Los Angeles, CA, USA
- Department of Neurology, University of California Los Angeles, Los Angeles, CA, USA
| | - Jae H Kim
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Sarah McCallum
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
- Center for Neural Science and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Alexandra Rogers
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Shalaka Wahane
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Michael V Sofroniew
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
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14
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Menendez M, Drozd A, Borawska K, Chmielewska JJ, Wu ML, Griffin CT. IL-1β Impacts Vascular Integrity and Lymphatic Function in the Embryonic Omentum. Circ Res 2022; 130:366-383. [PMID: 34986653 PMCID: PMC8813910 DOI: 10.1161/circresaha.121.319032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND The chromatin-remodeling enzyme BRG1 (brahma-related gene 1) regulates gene expression in a variety of rapidly differentiating cells during embryonic development. However, the critical genes that BRG1 regulates during lymphatic vascular development are unknown. METHODS We used genetic and imaging techniques to define the role of BRG1 in murine embryonic lymphatic development, although this approach inadvertently expanded our study to multiple interacting cell types. RESULTS We found that omental macrophages fine-tune an unexpected developmental process by which erythrocytes escaping from naturally discontinuous omental blood vessels are collected by nearby lymphatic vessels. Our data indicate that circulating fibrin(ogen) leaking from gaps in omental blood vessels can trigger inflammasome-mediated IL-1β (interleukin-1β) production and secretion from nearby macrophages. IL-1β destabilizes adherens junctions in omental blood and lymphatic vessels, contributing to both extravasation of erythrocytes and their uptake by lymphatics. BRG1 regulates IL-1β production in omental macrophages by transcriptionally suppressing the inflammasome trigger RIPK3 (receptor interacting protein kinase 3). CONCLUSIONS Genetic deletion of Brg1 in embryonic macrophages leads to excessive IL-1β production, erythrocyte leakage from blood vessels, and blood-filled lymphatics in the developing omentum. Altogether, these results highlight a novel context for epigenetically regulated crosstalk between macrophages, blood vessels, and lymphatics.
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Affiliation(s)
- Matthew Menendez
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Anna Drozd
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA,Present address: Novo Nordisk Foundation Center for Stem Cell Biology, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N., Denmark
| | - Katarzyna Borawska
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Joanna J. Chmielewska
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA,Present address: Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Meng-Ling Wu
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Courtney T. Griffin
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA,Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
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15
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Li J, Xu J, Jiang H, Zhang T, Ramakrishnan A, Shen L, Xu PX. Chromatin Remodelers Interact with Eya1 and Six2 to Target Enhancers to Control Nephron Progenitor Cell Maintenance. J Am Soc Nephrol 2021; 32:2815-2833. [PMID: 34716243 PMCID: PMC8806105 DOI: 10.1681/asn.2021040525] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 08/26/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Eya1 is a critical regulator of nephron progenitor cell specification and interacts with Six2 to promote NPC self-renewal. Haploinsufficiency of these genes causes kidney hypoplasia. However, how the Eya1-centered network operates remains unknown. METHODS We engineered a 2×HA-3×Flag-Eya1 knock-in mouse line and performed coimmunoprecipitation with anti-HA or -Flag to precipitate the multitagged-Eya1 and its associated proteins. Loss-of-function, transcriptome profiling, and genome-wide binding analyses for Eya1's interacting chromatin-remodeling ATPase Brg1 were carried out. We assayed the activity of the cis-regulatory elements co-occupied by Brg1/Six2 in vivo. RESULTS Eya1 and Six2 interact with the Brg1-based SWI/SNF complex during kidney development. Knockout of Brg1 results in failure of metanephric mesenchyme formation and depletion of nephron progenitors, which has been linked to loss of Eya1 expression. Transcriptional profiling shows conspicuous downregulation of important regulators for nephrogenesis in Brg1-deficient cells, including Lin28, Pbx1, and Dchs1-Fat4 signaling, but upregulation of podocyte lineage, oncogenic, and cell death-inducing genes, many of which Brg1 targets. Genome-wide binding analysis identifies Brg1 occupancy to a distal enhancer of Eya1 that drives nephron progenitor-specific expression. We demonstrate that Brg1 enrichment to two distal intronic enhancers of Pbx1 and a proximal promoter region of Mycn requires Six2 activity and that these Brg1/Six2-bound enhancers govern nephron progenitor-specific expression in response to Six2 activity. CONCLUSIONS Our results reveal an essential role for Brg1, its downstream pathways, and its interaction with Eya1-Six2 in mediating the fine balance among the self-renewal, differentiation, and survival of nephron progenitors.
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Affiliation(s)
- Jun Li
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Jinshu Xu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Huihui Jiang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Ting Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Aarthi Ramakrishnan
- Department of Neurosciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Li Shen
- Department of Neurosciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Pin-Xian Xu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York,Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York
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16
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Concepcion CP, Ma S, LaFave LM, Bhutkar A, Liu M, DeAngelo LP, Kim JY, Del Priore I, Schoenfeld AJ, Miller M, Kartha VK, Westcott PMK, Sanchez-Rivera FJ, Meli K, Gupta M, Bronson RT, Riely GJ, Rekhtman N, Rudin CM, Kim CF, Regev A, Buenrostro JD, Jacks T. SMARCA4 inactivation promotes lineage-specific transformation and early metastatic features in the lung. Cancer Discov 2021; 12:562-585. [PMID: 34561242 DOI: 10.1158/2159-8290.cd-21-0248] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 07/30/2021] [Accepted: 09/21/2021] [Indexed: 11/16/2022]
Abstract
SMARCA4/BRG1 encodes for one of two mutually exclusive ATPases present in mammalian SWI/SNF chromatin remodeling complexes and is frequently mutated in human lung adenocarcinoma. However, the functional consequences of SMARCA4 mutation on tumor initiation, progression, and chromatin regulation in lung cancer remain poorly understood. Here, we demonstrate that loss of Smarca4 sensitizes CCSP+ cells within the lung in a cell-type dependent fashion to malignant transformation and tumor progression, resulting in highly advanced dedifferentiated tumors and increased metastatic incidence. Consistent with these phenotypes, Smarca4-deficient primary tumors lack lung lineage transcription factor activities and resemble a metastatic cell state. Mechanistically, we show that Smarca4 loss impairs the function of all three classes of SWI/SNF complexes, resulting in decreased chromatin accessibility at lung lineage motifs and ultimately accelerating tumor progression. Thus, we propose that the SWI/SNF complex - via Smarca4 - acts as a gatekeeper for lineage-specific cellular transformation and metastasis during lung cancer evolution.
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Affiliation(s)
- Carla P Concepcion
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology
| | | | - Lindsay M LaFave
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology
| | - Arjun Bhutkar
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology
| | - Manyuan Liu
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology
| | - Lydia P DeAngelo
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology
| | | | - Isabella Del Priore
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology
| | | | - Manon Miller
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology
| | | | - Peter M K Westcott
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology
| | | | - Kevin Meli
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology
| | | | | | | | | | - Charles M Rudin
- Druckenmiller Center for Lung Cancer Research and Department of Medicine, Thoracic Oncology Service, Memorial Sloan Kettering Cancer Center
| | - Carla F Kim
- Stem Cell Program, Harvard University, Boston Children's Hospital
| | | | | | - Tyler Jacks
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology
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17
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Chromatin remodelers and lineage-specific factors interact to target enhancers to establish proneurosensory fate within otic ectoderm. Proc Natl Acad Sci U S A 2021; 118:2025196118. [PMID: 33723076 DOI: 10.1073/pnas.2025196118] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Specification of Sox2+ proneurosensory progenitors within otic ectoderm is a prerequisite for the production of sensory cells and neurons for hearing. However, the underlying molecular mechanisms driving this lineage specification remain unknown. Here, we show that the Brg1-based SWI/SNF chromatin-remodeling complex interacts with the neurosensory-specific transcriptional regulators Eya1/Six1 to induce Sox2 expression and promote proneurosensory-lineage specification. Ablation of the ATPase-subunit Brg1 or both Eya1/Six1 results in loss of Sox2 expression and lack of neurosensory identity, leading to abnormal apoptosis within the otic ectoderm. Brg1 binds to two of three distal 3' Sox2 enhancers occupied by Six1, and Brg1-binding to these regions depends on Eya1-Six1 activity. We demonstrate that the activity of these Sox2 enhancers in otic neurosensory cells specifically depends on binding to Six1. Furthermore, genome-wide and transcriptome profiling indicate that Brg1 may suppress apoptotic factor Map3k5 to inhibit apoptosis. Together, our findings reveal an essential role for Brg1, its downstream pathways, and their interactions with Six1/Eya1 in promoting proneurosensory fate induction in the otic ectoderm and subsequent neuronal lineage commitment and survival of otic cells.
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18
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Yoshikawa T, Fukuda A, Omatsu M, Namikawa M, Sono M, Fukunaga Y, Masuda T, Araki O, Nagao M, Ogawa S, Masuo K, Goto N, Hiramatsu Y, Muta Y, Tsuda M, Maruno T, Nakanishi Y, Kawada K, Takaishi S, Seno H. Brg1 is required to maintain colorectal cancer stem cells. J Pathol 2021; 255:257-269. [PMID: 34415580 DOI: 10.1002/path.5759] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 06/08/2021] [Accepted: 07/13/2021] [Indexed: 01/09/2023]
Abstract
Tumor cells capable of self-renewal and continuous production of progeny cells are called tumor stem cells (TSCs) and are considered to be potential therapeutic targets. However, the mechanisms underlying the survival and function of TSCs are not fully understood. We previously reported that chromatin remodeling regulator Brg1 is essential for intestinal stem cells in mice and Dclk1 is an intestinal TSC marker. In this study, we investigated the role of Brg1 in Dclk1+ intestinal tumor cells for the maintenance of intestinal tumors in mice. Specific ablation of Brg1 in Dclk1+ intestinal tumor cells reduced intestinal tumors in ApcMin mice, and continuous ablation of Brg1 maintained the reduction of intestinal tumors. Lineage tracing in the context of Brg1 ablation in Dclk1+ intestinal tumor cells revealed that Brg1-null Dclk1+ intestinal tumor cells did not give rise to their descendent tumor cells, indicating that Brg1 is essential for the self-renewal of Dclk1+ intestinal tumor cells. Five days after Brg1 ablation, we observed increased apoptosis in Dclk1+ tumor cells. Furthermore, Brg1 was crucial for the stemness of intestinal tumor cells in a spheroid culture system. BRG1 knockdown also impaired cell proliferation and increased apoptosis in human colorectal cancer (CRC) cells. Microarray analysis revealed that apoptosis-related genes were upregulated and stem cell-related genes were downregulated in human CRC cells by BRG1 suppression. Consistently, high BRG1 expression correlated with poor disease-specific survival in human CRC patients. These data indicate that Brg1 plays a crucial role in intestinal TSCs in mice by inhibiting apoptosis and is critical for cell survival and stem cell features in human CRC cells. Thus, BRG1 represents a new therapeutic target for human CRC. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Takaaki Yoshikawa
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Akihisa Fukuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Mayuki Omatsu
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Mio Namikawa
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Makoto Sono
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yuichi Fukunaga
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Department of Drug Discovery Medicine, Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tomonori Masuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Osamu Araki
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Munemasa Nagao
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Satoshi Ogawa
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kenji Masuo
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Laboratory for Malignancy Control Research (DSK Project), Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Norihiro Goto
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yukiko Hiramatsu
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yu Muta
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Motoyuki Tsuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takahisa Maruno
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yuki Nakanishi
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kenji Kawada
- Department of Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Shigeo Takaishi
- Laboratory for Malignancy Control Research (DSK Project), Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hiroshi Seno
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
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19
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Holdhof D, Schoof M, Al-Kershi S, Spohn M, Kresbach C, Göbel C, Hellwig M, Indenbirken D, Moreno N, Kerl K, Schüller U. Brahma-related gene 1 has time-specific roles during brain and eye development. Development 2021; 148:268382. [PMID: 34042968 DOI: 10.1242/dev.196147] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 05/04/2021] [Indexed: 11/20/2022]
Abstract
During development, gene expression is tightly controlled to facilitate the generation of the diverse cell types that form the central nervous system. Brahma-related gene 1 (Brg1, also known as Smarca4) is the catalytic subunit of the SWItch/sucrose nonfermentable (SWI/SNF) chromatin remodeling complex that regulates transcription. We investigated the role of Brg1 between embryonic day 6.5 (E6.5) and E14.5 in Sox2-positive neural stem cells (NSCs). Being without major consequences at E6.5 and E14.5, loss of Brg1 between E7.5 and E12.5 resulted in the formation of rosette-like structures in the subventricular zone, as well as morphological alterations and enlargement of neural retina (NR). Additionally, Brg1-deficient cells showed decreased survival in vitro and in vivo. Furthermore, we uncovered distinct changes in gene expression upon Brg1 loss, pointing towards impaired neuron functions, especially those involving synaptic communication and altered composition of the extracellular matrix. Comparison with mice deficient for integrase interactor 1 (Ini1, also known as Smarcb1) revealed that the enlarged NR was Brg1 specific and was not caused by a general dysfunction of the SWI/SNF complex. These results suggest a crucial role for Brg1 in NSCs during brain and eye development.
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Affiliation(s)
- Dörthe Holdhof
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.,Research Institute Children's Cancer Center Hamburg, 20251 Hamburg, Germany
| | - Melanie Schoof
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.,Research Institute Children's Cancer Center Hamburg, 20251 Hamburg, Germany
| | - Sina Al-Kershi
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.,Research Institute Children's Cancer Center Hamburg, 20251 Hamburg, Germany
| | - Michael Spohn
- Research Institute Children's Cancer Center Hamburg, 20251 Hamburg, Germany.,Bioinformatics Facility, University Medical Center, Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Catena Kresbach
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.,Research Institute Children's Cancer Center Hamburg, 20251 Hamburg, Germany
| | - Carolin Göbel
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.,Research Institute Children's Cancer Center Hamburg, 20251 Hamburg, Germany
| | - Malte Hellwig
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.,Research Institute Children's Cancer Center Hamburg, 20251 Hamburg, Germany
| | - Daniela Indenbirken
- Heinrich-Pette-Institute, Leibniz Institute for Experimental Virology, 20251 Hamburg, Germany
| | - Natalia Moreno
- Department of Pediatric Hematology and Oncology, University Children's Hospital Münster, 48149 Münster, Germany
| | - Kornelius Kerl
- Department of Pediatric Hematology and Oncology, University Children's Hospital Münster, 48149 Münster, Germany
| | - Ulrich Schüller
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.,Research Institute Children's Cancer Center Hamburg, 20251 Hamburg, Germany.,Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
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20
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Brg1 restrains the pro-inflammatory properties of ILC3s and modulates intestinal immunity. Mucosal Immunol 2021; 14:38-52. [PMID: 32612160 PMCID: PMC7790751 DOI: 10.1038/s41385-020-0317-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 04/10/2020] [Accepted: 06/11/2020] [Indexed: 02/04/2023]
Abstract
Group 3 innate lymphoid cells (ILC3s), a subset of the innate lymphoid cells, are abundantly present in the intestine and are crucial regulators of intestinal inflammation. Brg1 (Brahma-related gene 1), a catalytic subunit of the mammalian SWI-SNF-like chromatin-remodeling BAF complex, regulates the development and function of various immune cells. Here, by genetic deletion of Brg1 in ILC3s (Smarca4ΔILC3), we prove that Brg1 supports the differentiation of NKp46+ILC3s by promoting the T-bet expression in NKp46-ILC3s, which facilitates the conversion of NKp46-ILC3s to NKp46+ILC3s. Strikingly, Smarca4ΔILC3 mice of the Rag1-/- background develop spontaneous colitis accompanied with increased GM-CSF production in ILC3s. By construction of a mixed bone marrow chimeric system, we demonstrate that Brg1 enhances T-bet and inhibits GM-CSF expression in ILC3s through a cell-intrinsic manner. Blockade of GM-CSF ameliorates colitis in Rag1-/-Smarca4ΔILC3 mice, suggesting that the suppression of GM-CSF production from ILC3s by Brg1 serves as a critical mechanism for Brg1 to restrain intestinal inflammation. We have further demonstrated that Brg1 binds to the Tbx21 and Csf2 gene locus in ILC3s, and favors the active and repressive histones modifications on gene locus of Tbx21 and Csf2 respectively. Our work reveals the essential role of Brg1 in intestinal immunity by regulating ILC3s.
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21
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Innis SM, Cabot B. GBAF, a small BAF sub-complex with big implications: a systematic review. Epigenetics Chromatin 2020; 13:48. [PMID: 33143733 PMCID: PMC7607862 DOI: 10.1186/s13072-020-00370-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 10/23/2020] [Indexed: 12/01/2022] Open
Abstract
ATP-dependent chromatin remodeling by histone-modifying enzymes and chromatin remodeling complexes is crucial for maintaining chromatin organization and facilitating gene transcription. In the SWI/SNF family of ATP-dependent chromatin remodelers, distinct complexes such as BAF, PBAF, GBAF, esBAF and npBAF/nBAF are of particular interest regarding their implications in cellular differentiation and development, as well as in various diseases. The recently identified BAF subcomplex GBAF is no exception to this, and information is emerging linking this complex and its components to crucial events in mammalian development. Furthermore, given the essential nature of many of its subunits in maintaining effective chromatin remodeling function, it comes as no surprise that aberrant expression of GBAF complex components is associated with disease development, including neurodevelopmental disorders and numerous malignancies. It becomes clear that building upon our knowledge of GBAF and BAF complex function will be essential for advancements in both mammalian reproductive applications and the development of more effective therapeutic interventions and strategies. Here, we review the roles of the SWI/SNF chromatin remodeling subcomplex GBAF and its subunits in mammalian development and disease.
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Affiliation(s)
- Sarah M Innis
- Department of Animal Sciences, Purdue University, West Lafayette, IN, USA
| | - Birgit Cabot
- Department of Animal Sciences, Purdue University, West Lafayette, IN, USA.
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22
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Elsesser O, Fröb F, Küspert M, Tamm ER, Fujii T, Fukunaga R, Wegner M. Chromatin remodeler Ep400 ensures oligodendrocyte survival and is required for myelination in the vertebrate central nervous system. Nucleic Acids Res 2020; 47:6208-6224. [PMID: 31081019 PMCID: PMC6614847 DOI: 10.1093/nar/gkz376] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 04/26/2019] [Accepted: 05/02/2019] [Indexed: 11/27/2022] Open
Abstract
Differentiating oligodendrocytes generate myelin to ensure rapid saltatory conduction in the vertebrate central nervous system. Although oligodendroglial differentiation and myelination are accompanied by dramatic chromatin reorganizations, previously studied chromatin remodelers had only limited direct effects on the process. To study the functional significance of chromatin changes for myelination and identify relevant remodelers, we deleted Ep400, the central ATP-hydrolyzing subunit of the TIP60/EP400 complex, at defined times of mouse oligodendrocyte development. Whereas Ep400-deficient oligodendrocyte precursors develop normally, terminal differentiation and myelination are dramatically impaired. Mechanistically, Ep400 interacts with transcription factor Sox10, binds to regulatory regions of the Myrf gene and is required to induce this central transcriptional regulator of the myelination program. In addition to reduced and aberrant myelin formation, oligodendrocytes exhibit increased DNA damage and apoptosis so that numbers never reach wildtype levels during the short lifespan of Ep400-deficient mice. Ep400 deletion in already mature oligodendrocytes remains phenotypically inapparent arguing that Ep400 is dispensable for myelin maintenance. Given its essential function in myelin formation, modulation of Ep400 activity may be beneficial in conditions such as multiple sclerosis where this process is compromised.
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Affiliation(s)
- Olga Elsesser
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Franziska Fröb
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Melanie Küspert
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Ernst R Tamm
- Institut für Humananatomie und Embryologie, Universität Regensburg, Regensburg, Germany
| | - Toshihiro Fujii
- Department of Biochemistry, Osaka University of Pharmaceutical Sciences, Osaka, Japan
| | - Rikiro Fukunaga
- Department of Biochemistry, Osaka University of Pharmaceutical Sciences, Osaka, Japan
| | - Michael Wegner
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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23
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Wu T, Kamikawa YF, Donohoe ME. Brd4's Bromodomains Mediate Histone H3 Acetylation and Chromatin Remodeling in Pluripotent Cells through P300 and Brg1. Cell Rep 2019; 25:1756-1771. [PMID: 30428346 DOI: 10.1016/j.celrep.2018.10.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 11/10/2016] [Accepted: 09/28/2018] [Indexed: 12/22/2022] Open
Abstract
The pluripotent state of embryonic stem cells (ESCs) is defined by its transcriptome and epigenome. The chromatin reader Brd4 determines ESC identity. Although Brd4 regulation in gene transcription has been well described, its contribution to the chromatin landscape is less known. Here, we show that Brd4's bromodomains partner with the histone acetyltransferase P300, increasing its enzymatic activities. Augmenting histone acetylation by Brd4-P300 interaction recruits the chromatin remodeler Brg1 altering chromatin structure. This pathway is important for maintaining the expression and chromatin patterns of pluripotency-associated genes, such as Oct4, Nanog, and the X chromosome regulatory long noncoding RNAs Tsix and Xite. Furthermore, we show that the Brd4-P300 interaction regulates the de novo formation of chromatin marks during ESC differentiation, as exemplified by controlling the master regulators of mesoderm formation. Collectively, we delineate the function of Brd4 in organizing the chromatin structure that contributes to gene transcriptional regulation and cell fate determination.
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Affiliation(s)
- Tao Wu
- Burke Medical Research Institute, White Plains, NY 10605, USA; Department of Neuroscience, Brain Mind Research Institute, Department of Cell & Development, Weill Cornell Medical College, New York, NY 10065, USA
| | - Yasunao F Kamikawa
- Burke Medical Research Institute, White Plains, NY 10605, USA; Department of Neuroscience, Brain Mind Research Institute, Department of Cell & Development, Weill Cornell Medical College, New York, NY 10065, USA
| | - Mary E Donohoe
- Burke Medical Research Institute, White Plains, NY 10605, USA; Department of Neuroscience, Brain Mind Research Institute, Department of Cell & Development, Weill Cornell Medical College, New York, NY 10065, USA.
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24
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BRG1 attenuates colonic inflammation and tumorigenesis through autophagy-dependent oxidative stress sequestration. Nat Commun 2019; 10:4614. [PMID: 31601814 PMCID: PMC6787222 DOI: 10.1038/s41467-019-12573-z] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 09/11/2019] [Indexed: 12/17/2022] Open
Abstract
Autophagy is a central component of integrated stress responses that influences many inflammatory diseases, including inflammatory bowel disease (IBD) and colorectal cancer (CRC). While the core machinery is known, the molecular basis of the epigenetic regulation of autophagy and its role in colon inflammation remain largely undefined. Here, we report that BRG1, an ATPase subunit of the SWI/SNF chromatin remodeling complex, is required for the homeostatic maintenance of intestinal epithelial cells (IECs) to prevent the inflammation and tumorigenesis. BRG1 emerges as a key regulator that directly governs the transcription of Atg16l1, Ambra1, Atg7 and Wipi2, which are important for autophagosome biogenesis. Defective autophagy in BRG1-deficient IECs results in excess reactive oxygen species (ROS), which leads to the defects in barrier integrity. Together, our results establish that BRG1 may represent an autophagy checkpoint that is pathogenetically linked to colitis and is therefore likely a potential therapeutic target for disease intervention. Dysfunctional autophagy induces inflammation that contributes to tumorigenesis. Here, the authors show that loss of BRG1 impairs autophagy and enhances reactive oxygen species production to disrupt intestinal barrier integrity, leading to spontaneous colitis and subsequent colorectal cancer development.
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25
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Spaeth JM, Liu JH, Peters D, Guo M, Osipovich AB, Mohammadi F, Roy N, Bhushan A, Magnuson MA, Hebrok M, Wright CVE, Stein R. The Pdx1-Bound Swi/Snf Chromatin Remodeling Complex Regulates Pancreatic Progenitor Cell Proliferation and Mature Islet β-Cell Function. Diabetes 2019; 68:1806-1818. [PMID: 31201281 PMCID: PMC6702633 DOI: 10.2337/db19-0349] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 06/06/2019] [Indexed: 12/13/2022]
Abstract
Transcription factors positively and/or negatively impact gene expression by recruiting coregulatory factors, which interact through protein-protein binding. Here we demonstrate that mouse pancreas size and islet β-cell function are controlled by the ATP-dependent Swi/Snf chromatin remodeling coregulatory complex that physically associates with Pdx1, a diabetes-linked transcription factor essential to pancreatic morphogenesis and adult islet cell function and maintenance. Early embryonic deletion of just the Swi/Snf Brg1 ATPase subunit reduced multipotent pancreatic progenitor cell proliferation and resulted in pancreas hypoplasia. In contrast, removal of both Swi/Snf ATPase subunits, Brg1 and Brm, was necessary to compromise adult islet β-cell activity, which included whole-animal glucose intolerance, hyperglycemia, and impaired insulin secretion. Notably, lineage-tracing analysis revealed Swi/Snf-deficient β-cells lost the ability to produce the mRNAs for Ins and other key metabolic genes without effecting the expression of many essential islet-enriched transcription factors. Swi/Snf was necessary for Pdx1 to bind to the Ins gene enhancer, demonstrating the importance of this association in mediating chromatin accessibility. These results illustrate how fundamental the Pdx1:Swi/Snf coregulator complex is in the pancreas, and we discuss how disrupting their association could influence type 1 and type 2 diabetes susceptibility.
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Affiliation(s)
- Jason M Spaeth
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Jin-Hua Liu
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Daniel Peters
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
| | - Min Guo
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Anna B Osipovich
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Fardin Mohammadi
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
| | - Nilotpal Roy
- Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, CA
| | - Anil Bhushan
- Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, CA
| | - Mark A Magnuson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Matthias Hebrok
- Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, CA
| | | | - Roland Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
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26
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Menon DU, Shibata Y, Mu W, Magnuson T. Mammalian SWI/SNF collaborates with a polycomb-associated protein to regulate male germline transcription in the mouse. Development 2019; 146:dev174094. [PMID: 31043422 PMCID: PMC6803380 DOI: 10.1242/dev.174094] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 04/23/2019] [Indexed: 12/25/2022]
Abstract
A deficiency in BRG1, the catalytic subunit of the SWI/SNF chromatin remodeling complex, results in a meiotic arrest during spermatogenesis. Here, we explore the causative mechanisms. BRG1 is preferentially enriched at active promoters of genes essential for spermatogonial pluripotency and meiosis. In contrast, BRG1 is also associated with the repression of somatic genes. Chromatin accessibility at these target promoters is dependent upon BRG1. These results favor a model in which BRG1 coordinates spermatogenic transcription to ensure meiotic progression. In spermatocytes, BRG1 interacts with SCML2, a testis-specific PRC1 factor that is associated with the repression of somatic genes. We present evidence to suggest that BRG1 and SCML2 concordantly regulate genes during meiosis. Furthermore, BRG1 is required for the proper localization of SCML2 and its associated deubiquitylase, USP7, to the sex chromosomes during pachynema. SCML2-associated mono-ubiquitylation of histone H2A lysine 119 (H2AK119ub1) and acetylation of histone lysine 27 (H3K27ac) are elevated in Brg1cKO testes. Coincidentally, the PRC1 ubiquitin ligase RNF2 is activated while a histone H2A/H2B deubiquitylase USP3 is repressed. Thus, BRG1 impacts the male epigenome by influencing the localization and expression of epigenetic modifiers. This mechanism highlights a novel paradigm of cooperativity between SWI/SNF and PRC1.
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Affiliation(s)
- Debashish U Menon
- Department of Genetics, and Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7264, USA
| | - Yoichiro Shibata
- Department of Genetics, and Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7264, USA
| | - Weipeng Mu
- Department of Genetics, and Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7264, USA
| | - Terry Magnuson
- Department of Genetics, and Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7264, USA
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27
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Deletion of Brg1 causes stereocilia bundle fusion and cuticular plate loss in vestibular hair cells. Hear Res 2019; 377:247-259. [PMID: 31003036 DOI: 10.1016/j.heares.2019.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 03/16/2019] [Accepted: 04/03/2019] [Indexed: 11/22/2022]
Abstract
Brg1 is an ATPase subunit of the SWI/SNF chromatin-remodeling complex, and it is indispensable for the development and homeostasis of various organs. Conditional deletion of Brg1 in cochlea hair cells (HCs) leads to multiple structural defects and profound deafness. However, the premature death of Brg1-deficient cochlea HCs hindered further study of the role of Brg1. In contrast to cochlea HCs, Brg1-deficient vestibular HCs survived for a long time. Therefore, HC apical structure and vestibular function were examined in inner HC-specific conditional Brg1 knockout mice. Vestibular HCs exhibited fused and elongated stereocilia bundles after deletion of Brg1, and the cuticular plate was absent in most HCs with fused stereocilia bundles. HC loss was observed in conditional Brg1 knockout mice at the age of 12 months. Morphological defects and HC loss were primarily restricted in the striolar region of the utricle and saccule and in the central region of ampulla. The behavioral tests revealed that Brg1 deletion in HCs caused vestibular dysfunction in older adult mice. These results suggest that Brg1 may play specific roles in the maintenance of the HC stereocilia bundle and the cuticular plate.
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28
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Vander Schaaf NA, Oghamian S, Park JA, Kang L, Laird PW, Lee KH. In vivo Application of the REMOTE-control System for the Manipulation of Endogenous Gene Expression. J Vis Exp 2019. [PMID: 30985765 DOI: 10.3791/59235] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Here we describe a protocol for implementing the REMOTE-control system (Reversible Manipulation of Transcription at Endogenous loci), which allows for reversible and tunable expression control of an endogenous gene of interest in living model systems. The REMOTE-control system employs enhanced lac repression and tet activation systems to achieve down- or upregulation of a target gene within a single biological system. Tight repression can be achieved from repressor binding sites flexibly located far downstream of a transcription start site by inhibiting transcription elongation. Robust upregulation can be attained by enhancing the transcription of an endogenous gene by targeting tet transcriptional activators to the cognate promoter. This reversible and tunable expression control can be applied and withdrawn repeatedly in organisms. The potency and versatility of the system, as demonstrated for endogenous Dnmt1 here, will allow more precise in vivo functional analyses by enabling investigation of gene function at various expression levels and by testing the reversibility of a phenotype.
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Affiliation(s)
| | | | - Jin-A Park
- Center for Epigenetics, Van Andel Research Institute
| | - Liang Kang
- Center for Epigenetics, Van Andel Research Institute
| | - Peter W Laird
- Center for Epigenetics, Van Andel Research Institute
| | - Kwang-Ho Lee
- Center for Epigenetics, Van Andel Research Institute;
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29
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Ding Y, Li N, Dong B, Guo W, Wei H, Chen Q, Yuan H, Han Y, Chang H, Kan S, Wang X, Pan Q, Wu P, Peng C, Qiu T, Li Q, Gao D, Xue W, Qin J. Chromatin remodeling ATPase BRG1 and PTEN are synthetic lethal in prostate cancer. J Clin Invest 2019; 129:759-773. [PMID: 30496141 DOI: 10.1172/jci123557] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 11/20/2018] [Indexed: 12/19/2022] Open
Abstract
Loss of phosphatase and tensin homolog (PTEN) represents one hallmark of prostate cancer (PCa). However, restoration of PTEN or inhibition of the activated PI3K/AKT pathway has shown limited success, prompting us to identify obligate targets for disease intervention. We hypothesized that PTEN loss might expose cells to unique epigenetic vulnerabilities. Here, we identified a synthetic lethal relationship between PTEN and Brahma-related gene 1 (BRG1), an ATPase subunit of the SWI/SNF chromatin remodeling complex. Higher BRG1 expression in tumors with low PTEN expression was associated with a worse clinical outcome. Genetically engineered mice (GEMs) and organoid assays confirmed that ablation of PTEN sensitized the cells to BRG1 depletion. Mechanistically, PTEN loss stabilized BRG1 protein through the inhibition of the AKT/GSK3β/FBXW7 axis. Increased BRG1 expression in PTEN-deficient PCa cells led to chromatin remodeling into configurations that drove a protumorigenic transcriptome, causing cells to become further addicted to BRG1. Furthermore, we showed in preclinical models that BRG1 antagonist selectively inhibited the progression of PTEN-deficient prostate tumors. Together, our results highlight the synthetic lethal relationship between PTEN and BRG1 and support targeting BRG1 as an effective approach to the treatment of PTEN-deficient PCa.
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Affiliation(s)
- Yufeng Ding
- CAS Key Laboratory of Tissue Microenvironment and Tumor, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Nutrition and Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China.,Department of Urology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Ni Li
- CAS Key Laboratory of Tissue Microenvironment and Tumor, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Nutrition and Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Baijun Dong
- Department of Urology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Wangxin Guo
- State Key Laboratory of Cell Biology, CAS Key Laboratory of Systems Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Hui Wei
- State Key Laboratory of Cell Biology, CAS Key Laboratory of Systems Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Qilong Chen
- CAS Key Laboratory of Tissue Microenvironment and Tumor, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Nutrition and Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Huairui Yuan
- CAS Key Laboratory of Tissue Microenvironment and Tumor, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Nutrition and Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Ying Han
- CAS Key Laboratory of Tissue Microenvironment and Tumor, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Nutrition and Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Hanwen Chang
- CAS Key Laboratory of Tissue Microenvironment and Tumor, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Nutrition and Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Shan Kan
- CAS Key Laboratory of Tissue Microenvironment and Tumor, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Nutrition and Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Xuege Wang
- CAS Key Laboratory of Tissue Microenvironment and Tumor, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Nutrition and Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Qiang Pan
- CAS Key Laboratory of Tissue Microenvironment and Tumor, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Nutrition and Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Ping Wu
- National Facility for Protein Science in Shanghai, Zhangjiang Lab, Shanghai, China
| | - Chao Peng
- National Facility for Protein Science in Shanghai, Zhangjiang Lab, Shanghai, China
| | - Tong Qiu
- Department of Obstetrics, Gynecology and Pediatrics, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, China
| | - Qintong Li
- Department of Obstetrics, Gynecology and Pediatrics, West China Second University Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, China
| | - Dong Gao
- State Key Laboratory of Cell Biology, CAS Key Laboratory of Systems Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Wei Xue
- Department of Urology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Jun Qin
- CAS Key Laboratory of Tissue Microenvironment and Tumor, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Nutrition and Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China.,Department of Urology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
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30
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Tsuda M, Fukuda A, Roy N, Hiramatsu Y, Leonhardt L, Kakiuchi N, Hoyer K, Ogawa S, Goto N, Ikuta K, Kimura Y, Matsumoto Y, Takada Y, Yoshioka T, Maruno T, Yamaga Y, Kim GE, Akiyama H, Ogawa S, Wright CV, Saur D, Takaori K, Uemoto S, Hebrok M, Chiba T, Seno H. The BRG1/SOX9 axis is critical for acinar cell-derived pancreatic tumorigenesis. J Clin Invest 2018; 128:3475-3489. [PMID: 30010625 PMCID: PMC6063489 DOI: 10.1172/jci94287] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 05/23/2018] [Indexed: 02/06/2023] Open
Abstract
Chromatin remodeler Brahma related gene 1 (BRG1) is silenced in approximately 10% of human pancreatic ductal adenocarcinomas (PDAs). We previously showed that BRG1 inhibits the formation of intraductal pancreatic mucinous neoplasm (IPMN) and that IPMN-derived PDA originated from ductal cells. However, the role of BRG1 in pancreatic intraepithelial neoplasia-derived (PanIN-derived) PDA that originated from acinar cells remains elusive. Here, we found that exclusive elimination of Brg1 in acinar cells of Ptf1a-CreER; KrasG12D; Brg1fl/fl mice impaired the formation of acinar-to-ductal metaplasia (ADM) and PanIN independently of p53 mutation, while PDA formation was inhibited in the presence of p53 mutation. BRG1 bound to regions of the Sox9 promoter to regulate its expression and was critical for recruitment of upstream regulators, including PDX1, to the Sox9 promoter and enhancer in acinar cells. SOX9 expression was downregulated in BRG1-depleted ADMs/PanINs. Notably, Sox9 overexpression canceled this PanIN-attenuated phenotype in KBC mice. Furthermore, Brg1 deletion in established PanIN by using a dual recombinase system resulted in regression of the lesions in mice. Finally, BRG1 expression correlated with SOX9 expression in human PDAs. In summary, BRG1 is critical for PanIN initiation and progression through positive regulation of SOX9. Thus, the BRG1/SOX9 axis is a potential target for PanIN-derived PDA.
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Affiliation(s)
- Motoyuki Tsuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Akihisa Fukuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Nilotpal Roy
- Diabetes Center, Department of Medicine, UCSF, San Francisco, California, USA
| | - Yukiko Hiramatsu
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Laura Leonhardt
- Diabetes Center, Department of Medicine, UCSF, San Francisco, California, USA
| | - Nobuyuki Kakiuchi
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
- Department of Pathology and Tumor Biology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kaja Hoyer
- Department of Pathology and Tumor Biology, Kyoto University Graduate School of Medicine, Kyoto, Japan
- Hematology, Oncology and Tumorimmunology, Charite–Universitätsmedizin Berlin, Berlin, Germany
| | - Satoshi Ogawa
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Norihiro Goto
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kozo Ikuta
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yoshito Kimura
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yoshihide Matsumoto
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yutaka Takada
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takuto Yoshioka
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takahisa Maruno
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yuichi Yamaga
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Grace E. Kim
- Department of Pathology, UCSF, San Francisco, California, USA
| | | | - Seishi Ogawa
- Department of Pathology and Tumor Biology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Christopher V. Wright
- Program in Developmental Biology and Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Dieter Saur
- Department of Internal Medicine II, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Kyoichi Takaori
- Division of Hepatobiliary-Pancreatic Surgery and Transplantation, Department of Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Shinji Uemoto
- Division of Hepatobiliary-Pancreatic Surgery and Transplantation, Department of Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Matthias Hebrok
- Diabetes Center, Department of Medicine, UCSF, San Francisco, California, USA
| | - Tsutomu Chiba
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
- Kansai Electric Power Hospital, Osaka, Japan
| | - Hiroshi Seno
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
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31
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Kimura Y, Fukuda A, Ogawa S, Maruno T, Takada Y, Tsuda M, Hiramatsu Y, Araki O, Nagao M, Yoshikawa T, Ikuta K, Yoshioka T, Wang Z, Akiyama H, Wright CV, Takaori K, Uemoto S, Chiba T, Seno H. ARID1A Maintains Differentiation of Pancreatic Ductal Cells and Inhibits Development of Pancreatic Ductal Adenocarcinoma in Mice. Gastroenterology 2018; 155:194-209.e2. [PMID: 29604291 DOI: 10.1053/j.gastro.2018.03.039] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 03/05/2018] [Accepted: 03/22/2018] [Indexed: 01/17/2023]
Abstract
BACKGROUND & AIMS The ARID1A gene encodes a protein that is part of the large adenosine triphosphate (ATP)-dependent chromatin remodeling complex SWI/SNF and is frequently mutated in human pancreatic ductal adenocarcinomas (PDACs). We investigated the functions of ARID1A during formation of PDACs in mice. METHODS We performed studies with Ptf1a-Cre;KrasG12D mice, which express activated Kras in the pancreas and develop pancreatic intraepithelial neoplasias (PanINs), as well as those with disruption of Aird1a (Ptf1a-Cre;KrasG12D;Arid1af/f mice) or disruption of Brg1 (encodes a catalytic ATPase of the SWI/SNF complex) (Ptf1a-Cre;KrasG12D; Brg1f/fmice). Pancreatic ductal cells (PDCs) were isolated from Arid1af/f mice and from Arid1af/f;SOX9OE mice, which overexpress human SOX9 upon infection with an adenovirus-expressing Cre recombinase. Pancreatic tissues were collected from all mice and analyzed by histology and immunohistochemistry; cells were isolated and grown in 2-dimensional and 3-dimensional cultures. We performed microarray analyses to compare gene expression patterns in intraductal papillary mucinous neoplasms (IPMNs) from the different strains of mice. We obtained 58 samples of IPMNs and 44 samples of PDACs from patients who underwent pancreatectomy in Japan and analyzed them by immunohistochemistry. RESULTS Ptf1a-Cre;KrasG12D mice developed PanINs, whereas Ptf1a-Cre;KrasG12D;Arid1af/f mice developed IPMNs and PDACs; IPMNs originated from PDCs. ARID1A-deficient IPMNs did not express SOX9. ARID1A-deficient PDCs had reduced expression of SOX9 and dedifferentiated in culture. Overexpression of SOX9 in these cells allowed them to differentiate and prevented dilation of ducts. Among mice with pancreatic expression of activated Kras, those with disruption of Arid1a developed fewer PDACs from IPMNs than mice with disruption of Brg1. ARID1A-deficient IPMNs had reduced activity of the mTOR pathway. Human IPMN and PDAC specimens had reduced levels of ARID1A, SOX9, and phosphorylated S6 (a marker of mTOR pathway activation). Levels of ARID1A correlated with levels of SOX9 and phosphorylated S6. CONCLUSIONS ARID1A regulates expression of SOX9, activation of the mTOR pathway, and differentiation of PDCs. ARID1A inhibits formation of PDACs from IPMNs in mice with pancreatic expression of activated KRAS and is down-regulated in IPMN and PDAC tissues from patients.
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Affiliation(s)
- Yoshito Kimura
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Akihisa Fukuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan.
| | - Satoshi Ogawa
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takahisa Maruno
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yutaka Takada
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Motoyuki Tsuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yukiko Hiramatsu
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Osamu Araki
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Munemasa Nagao
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takaaki Yoshikawa
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kozo Ikuta
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takuto Yoshioka
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Zong Wang
- Department of Cardiac Surgery, Cardiovascular Research Center, University of Michigan, Ann Arbor, Michigan
| | | | - Christopher V Wright
- Program in Developmental Biology and Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Kyoichi Takaori
- Division of Hepatobiliary-Pancreatic Surgery and Transplantation, Department of Surgery, Kyoto University Graduate School of Medicine, Kyoto Japan
| | - Shinji Uemoto
- Division of Hepatobiliary-Pancreatic Surgery and Transplantation, Department of Surgery, Kyoto University Graduate School of Medicine, Kyoto Japan
| | - Tsutomu Chiba
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hiroshi Seno
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
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32
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Lissanu Deribe Y, Sun Y, Terranova C, Khan F, Martinez-Ledesma J, Gay J, Gao G, Mullinax RA, Khor T, Feng N, Lin YH, Wu CC, Reyes C, Peng Q, Robinson F, Inoue A, Kochat V, Liu CG, Asara JM, Moran C, Muller F, Wang J, Fang B, Papadimitrakopoulou V, Wistuba II, Rai K, Marszalek J, Futreal PA. Mutations in the SWI/SNF complex induce a targetable dependence on oxidative phosphorylation in lung cancer. Nat Med 2018; 24:1047-1057. [PMID: 29892061 DOI: 10.1038/s41591-018-0019-5] [Citation(s) in RCA: 150] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 03/20/2018] [Indexed: 01/09/2023]
Abstract
Lung cancer is a devastating disease that remains a top cause of cancer mortality. Despite improvements with targeted and immunotherapies, the majority of patients with lung cancer lack effective therapies, underscoring the need for additional treatment approaches. Genomic studies have identified frequent alterations in components of the SWI/SNF chromatin remodeling complex including SMARCA4 and ARID1A. To understand the mechanisms of tumorigenesis driven by mutations in this complex, we developed a genetically engineered mouse model of lung adenocarcinoma by ablating Smarca4 in the lung epithelium. We demonstrate that Smarca4 acts as a bona fide tumor suppressor and cooperates with p53 loss and Kras activation. Gene expression analyses revealed the signature of enhanced oxidative phosphorylation (OXPHOS) in SMARCA4 mutant tumors. We further show that SMARCA4 mutant cells have enhanced oxygen consumption and increased respiratory capacity. Importantly, SMARCA4 mutant lung cancer cell lines and xenograft tumors have marked sensitivity to inhibition of OXPHOS by a novel small molecule, IACS-010759, that is under clinical development. Mechanistically, we show that SMARCA4-deficient cells have a blunted transcriptional response to energy stress creating a therapeutically exploitable synthetic lethal interaction. These findings provide the mechanistic basis for further development of OXPHOS inhibitors as therapeutics against SWI/SNF mutant tumors.
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Affiliation(s)
- Yonathan Lissanu Deribe
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
| | - Yuting Sun
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Christopher Terranova
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Fatima Khan
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Juan Martinez-Ledesma
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jason Gay
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Guang Gao
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Robert A Mullinax
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Tin Khor
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ningping Feng
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Yu-Hsi Lin
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Chia-Chin Wu
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Claudia Reyes
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Qian Peng
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Frederick Robinson
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Akira Inoue
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Veena Kochat
- Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Chang-Gong Liu
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - John M Asara
- Division of Signal Transduction, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Cesar Moran
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Florian Muller
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jing Wang
- Department of Bioinformatics & Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Bingliang Fang
- Department of Thoracic, Head & Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Vali Papadimitrakopoulou
- Department of Thoracic, Head & Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ignacio I Wistuba
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Kunal Rai
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Joseph Marszalek
- Institute for Applied Cancer Science, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - P Andrew Futreal
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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33
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Li L, Zhou Y, Lu QR, Shi Y, Yang J. Brahma compensates the role of brahma-related gene 1 in liver regeneration of albumin-Cre; brahma-related gene 1loxP/loxP mice. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2017; 10:11563-11571. [PMID: 31966512 PMCID: PMC6966071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 11/08/2017] [Indexed: 06/10/2023]
Abstract
BACKGROUND Brahma-related gene 1 and brahma, which are catalytic components of the mammalian chromatin remodeling complex, express ubiquitously in mammalian tissues, including the liver. Although both are involved in numerous biological processes, including cell growth, proliferation, and tumorigenesis, their roles in liver regeneration are still unclear. METHODS We developed special knockout mice in which brahma-related gene 1 was deleted in the hepatocytes. After that, partial hepatectomy and chemical injury models were used to investigate the regulation process in liver regeneration. RESULTS Notably, brahma-related gene 1 increased in liver regeneration following hepatic injury; however, the loss of brahma-related gene 1 neither prominently disturbed the development, growth, and metabolism of the liver nor impaired liver regeneration even after inducing tumorigenesis. In contrast, the brahma expression maintained at stable levels in the early phase of liver regeneration. Intriguingly, additional brahma silencing in albumin-Cre; brahma-related gene 1loxP/loxP mice through short-hairpin ribonucleic acid decreased the proliferation of hepatocytes, resulting in delayed liver regeneration. CONCLUSIONS In contrast to the accepted notion that brahma could compensate the role of brahma-related gene 1 in liver regeneration by increasing its expression volume, the results of this study found that the deficiency of both brahma-related gene 1 and brahma significantly delays liver regeneration.
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Affiliation(s)
- Lei Li
- Department of Liver Surgery, West China Hospital of Sichuan UniversityChengdu, China
- Department of Laboratory of Pathology, West China Hospital of Sichuan UniversityChengdu, China
| | - Yongjie Zhou
- Department of Pathology, West China Hospital of Sichuan UniversityChengdu, China
- Department of Laboratory of Pathology, West China Hospital of Sichuan UniversityChengdu, China
| | - Q Richard Lu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Ministry of Education), State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan UniversityChengdu, China
| | - Yujun Shi
- Department of Pathology, West China Hospital of Sichuan UniversityChengdu, China
- Department of Laboratory of Pathology, West China Hospital of Sichuan UniversityChengdu, China
| | - Jiayin Yang
- Department of Liver Surgery, West China Hospital of Sichuan UniversityChengdu, China
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Marathe HG, Watkins-Chow DE, Weider M, Hoffmann A, Mehta G, Trivedi A, Aras S, Basuroy T, Mehrotra A, Bennett DC, Wegner M, Pavan WJ, de la Serna IL. BRG1 interacts with SOX10 to establish the melanocyte lineage and to promote differentiation. Nucleic Acids Res 2017; 45:6442-6458. [PMID: 28431046 PMCID: PMC5499657 DOI: 10.1093/nar/gkx259] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 04/04/2017] [Indexed: 12/30/2022] Open
Abstract
Mutations in SOX10 cause neurocristopathies which display varying degrees of hypopigmentation. Using a sensitized mutagenesis screen, we identified Smarca4 as a modifier gene that exacerbates the phenotypic severity of Sox10 haplo-insufficient mice. Conditional deletion of Smarca4 in SOX10 expressing cells resulted in reduced numbers of cranial and ventral trunk melanoblasts. To define the requirement for the Smarca4 -encoded BRG1 subunit of the SWI/SNF chromatin remodeling complex, we employed in vitro models of melanocyte differentiation in which induction of melanocyte-specific gene expression is closely linked to chromatin alterations. We found that BRG1 was required for expression of Dct, Tyrp1 and Tyr, genes that are regulated by SOX10 and MITF and for chromatin remodeling at distal and proximal regulatory sites. SOX10 was found to physically interact with BRG1 in differentiating melanocytes and binding of SOX10 to the Tyrp1 distal enhancer temporally coincided with recruitment of BRG1. Our data show that SOX10 cooperates with MITF to facilitate BRG1 binding to distal enhancers of melanocyte-specific genes. Thus, BRG1 is a SOX10 co-activator, required to establish the melanocyte lineage and promote expression of genes important for melanocyte function.
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Affiliation(s)
- Himangi G Marathe
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Dawn E Watkins-Chow
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-4472, USA
| | - Matthias Weider
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Alana Hoffmann
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Gaurav Mehta
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Archit Trivedi
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Shweta Aras
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Tupa Basuroy
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Aanchal Mehrotra
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Dorothy C Bennett
- Molecular and Clinical Sciences Research Institute, St George's, University of London, London SW17 0RE, UK
| | - Michael Wegner
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - William J Pavan
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-4472, USA
| | - Ivana L de la Serna
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
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35
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Deletion of SMARCA4 impairs alveolar epithelial type II cells proliferation and aggravates pulmonary fibrosis in mice. Genes Dis 2017; 4:204-214. [PMID: 30258924 PMCID: PMC6147121 DOI: 10.1016/j.gendis.2017.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 10/11/2017] [Indexed: 02/05/2023] Open
Abstract
Alveolar epithelial cells (AECs) injury and failed reconstitution of the AECs barrier are both integral to alveolar flooding and subsequent pulmonary fibrosis (PF). Nevertheless, the exact mechanisms regulating the regeneration of AECs post-injury still remain unclear. SMARCA4 is a part of the large ATP-dependent chromatin remodelling complex SWI/SNF, which is essential for kidney and heart fibrosis. We investigates SMARCA4 function in lung fibrosis by establishing PF mice model with bleomycin firstly and found that the expression of SMARCA4 was mainly enhanced in alveolar type II (ATII) cells. Moreover, we established an alveolar epithelium-specific SMARCA4-deleted SP-C-rtTA/(tetO)7-Cre/SMARCA4f/f mice (SOSM4Δ/Δ) model, as well as a new SMARCA4-deleted alveolar type II (ATII)-like mle-12 cell line. We found that the bleomycin-induced PF was more aggressive in SOSM4Δ/Δ mice. Also, the proliferation of ATII cells was decreased with the loss of SMARCA4 in vivo and in vitro. In addition, we observed increased proliferation of ATII cells accompanied by abnormally high expression of SMARCA4 in human PF lung sections. These data uncovered the indispensable role of SMARCA4 in the proliferation of ATII cells, which might affect the progression of PF.
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Vieira JM, Howard S, Villa Del Campo C, Bollini S, Dubé KN, Masters M, Barnette DN, Rohling M, Sun X, Hankins LE, Gavriouchkina D, Williams R, Metzger D, Chambon P, Sauka-Spengler T, Davies B, Riley PR. BRG1-SWI/SNF-dependent regulation of the Wt1 transcriptional landscape mediates epicardial activity during heart development and disease. Nat Commun 2017; 8:16034. [PMID: 28737171 PMCID: PMC5527284 DOI: 10.1038/ncomms16034] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 05/23/2017] [Indexed: 01/02/2023] Open
Abstract
Epicardium-derived cells (EPDCs) contribute cardiovascular cell types during development and in adulthood respond to Thymosin β4 (Tβ4) and myocardial infarction (MI) by reactivating a fetal gene programme to promote neovascularization and cardiomyogenesis. The mechanism for epicardial gene (re-)activation remains elusive. Here we reveal that BRG1, the essential ATPase subunit of the SWI/SNF chromatin–remodelling complex, is required for expression of Wilms’ tumour 1 (Wt1), fetal EPDC activation and subsequent differentiation into coronary smooth muscle, and restores Wt1 activity upon MI. BRG1 physically interacts with Tβ4 and is recruited by CCAAT/enhancer-binding protein β (C/EBPβ) to discrete regulatory elements in the Wt1 locus. BRG1-Tβ4 co-operative binding promotes optimal transcription of Wt1 as the master regulator of embryonic EPDCs. Moreover, chromatin immunoprecipitation-sequencing reveals BRG1 binding at further key loci suggesting SWI/SNF activity across the fetal epicardial gene programme. These findings reveal essential functions for chromatin–remodelling in the activation of EPDCs during cardiovascular development and repair. Priming of the adult mouse heart with Tβ4 activates dormant epicardium-derived cells to aid repair of injured myocardium. Here, Vieira et al. explain this process and show that Tβ4 binds a chromatin remodeller BRG1 and activates Wt1, the key regulator of epicardial epithelial-to-mesenchymal transformation, by altering the epigenetic landscape of the Wt1 locus.
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Affiliation(s)
- Joaquim Miguel Vieira
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK.,Molecular Medicine Unit, UCL Institute of Child Health, London WC1N 1EH, UK
| | - Sara Howard
- Molecular Medicine Unit, UCL Institute of Child Health, London WC1N 1EH, UK
| | - Cristina Villa Del Campo
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Sveva Bollini
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Karina N Dubé
- Molecular Medicine Unit, UCL Institute of Child Health, London WC1N 1EH, UK
| | - Megan Masters
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Damien N Barnette
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Mala Rohling
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Xin Sun
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Laura E Hankins
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Daria Gavriouchkina
- Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK
| | - Ruth Williams
- Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK
| | - Daniel Metzger
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, INSERM U964/CNRS UMR 7104/Université de Strasbourg, 67404 IllKirch Cedex, France
| | - Pierre Chambon
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, INSERM U964/CNRS UMR 7104/Université de Strasbourg, 67404 IllKirch Cedex, France
| | - Tatjana Sauka-Spengler
- Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, UK
| | - Benjamin Davies
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Paul R Riley
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK.,Molecular Medicine Unit, UCL Institute of Child Health, London WC1N 1EH, UK
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Wu Q, Lian JB, Stein JL, Stein GS, Nickerson JA, Imbalzano AN. The BRG1 ATPase of human SWI/SNF chromatin remodeling enzymes as a driver of cancer. Epigenomics 2017; 9:919-931. [PMID: 28521512 PMCID: PMC5705788 DOI: 10.2217/epi-2017-0034] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Mammalian SWI/SNF enzymes are ATP-dependent remodelers of chromatin structure. These multisubunit enzymes are heterogeneous in composition; there are two catalytic ATPase subunits, BRM and BRG1, that are mutually exclusive, and additional subunits are incorporated in a combinatorial manner. Recent findings indicate that approximately 20% of human cancers contain mutations in SWI/SNF enzyme subunits, leading to the conclusion that the enzyme subunits are critical tumor suppressors. However, overexpression of specific subunits without apparent mutation is emerging as an alternative mechanism by which cellular transformation may occur. Here we highlight recent evidence linking elevated expression of the BRG1 ATPase to tissue-specific cancers and work suggesting that inhibiting BRG1 may be an effective therapeutic strategy.
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Affiliation(s)
- Qiong Wu
- Department of Pediatrics, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
| | - Jane B Lian
- Department of Biochemistry, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington, VT 05405, USA
| | - Janet L Stein
- Department of Biochemistry, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington, VT 05405, USA
| | - Gary S Stein
- Department of Biochemistry, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington, VT 05405, USA
| | - Jeffrey A Nickerson
- Department of Pediatrics, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
| | - Anthony N Imbalzano
- Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA
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Willis MS, Holley DW, Wang Z, Chen X, Quintana M, Jensen BC, Tannu M, Parker J, Jeyaraj D, Jain MK, Wolfram JA, Lee HG, Bultman SJ. BRG1 and BRM function antagonistically with c-MYC in adult cardiomyocytes to regulate conduction and contractility. J Mol Cell Cardiol 2017; 105:99-109. [PMID: 28232072 DOI: 10.1016/j.yjmcc.2017.02.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 01/27/2017] [Accepted: 02/15/2017] [Indexed: 12/15/2022]
Abstract
RATIONALE The contractile dysfunction that underlies heart failure involves perturbations in multiple biological processes ranging from metabolism to electrophysiology. Yet the epigenetic mechanisms that are altered in this disease state have not been elucidated. SWI/SNF chromatin-remodeling complexes are plausible candidates based on mouse knockout studies demonstrating a combined requirement for the BRG1 and BRM catalytic subunits in adult cardiomyocytes. Brg1/Brm double mutants exhibit metabolic and mitochondrial defects and are not viable although their cause of death has not been ascertained. OBJECTIVE To determine the cause of death of Brg1/Brm double-mutant mice, to test the hypothesis that BRG1 and BRM are required for cardiac contractility, and to identify relevant downstream target genes. METHODS AND RESULTS A tamoxifen-inducible gene-targeting strategy utilizing αMHC-Cre-ERT was implemented to delete both SWI/SNF catalytic subunits in adult cardiomyocytes. Brg1/Brm double-mutant mice were monitored by echocardiography and electrocardiography, and they underwent rapidly progressive ventricular dysfunction including conduction defects and arrhythmias that culminated in heart failure and death within 3weeks. Mechanistically, BRG1/BRM repressed c-Myc expression, and enforced expression of a DOX-inducible c-MYC trangene in mouse cardiomyocytes phenocopied the ventricular conduction defects observed in Brg1/Brm double mutants. BRG1/BRM and c-MYC had opposite effects on the expression of cardiac conduction genes, and the directionality was consistent with their respective loss- and gain-of-function phenotypes. To support the clinical relevance of this mechanism, BRG1/BRM occupancy was diminished at the same target genes in human heart failure cases compared to controls, and this correlated with increased c-MYC expression and decreased CX43 and SCN5A expression. CONCLUSION BRG1/BRM and c-MYC have an antagonistic relationship regulating the expression of cardiac conduction genes that maintain contractility, which is reminiscent of their antagonistic roles as a tumor suppressor and oncogene in cancer.
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Affiliation(s)
- Monte S Willis
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, USA; Department of Pathology & Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Darcy Wood Holley
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Zhongjing Wang
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, USA
| | - Xin Chen
- Department of Neurosurgery, Shandong Provincial Hospital Affiliated to Shandong University, 250021 Jinan, PR China
| | - Megan Quintana
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Brian C Jensen
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, USA
| | - Manasi Tannu
- Department of Neurosurgery, Shandong Provincial Hospital Affiliated to Shandong University, 250021 Jinan, PR China
| | - Joel Parker
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Darwin Jeyaraj
- Department of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA; Harrington Discovery Institute, University Hospitals Harrington Heart & Vascular Institute, Cleveland, OH 44106, USA
| | - Mukesh K Jain
- Department of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA; Harrington Discovery Institute, University Hospitals Harrington Heart & Vascular Institute, Cleveland, OH 44106, USA
| | - Julie A Wolfram
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Hyoung-Gon Lee
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX 78249, USA.
| | - Scott J Bultman
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
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Marquez-Vilendrer SB, Rai SK, Gramling SJ, Lu L, Reisman DN. BRG1 and BRM loss selectively impacts RB and P53, respectively: BRG1 and BRM have differential functions in vivo. Oncoscience 2016; 3:337-350. [PMID: 28105458 PMCID: PMC5235922 DOI: 10.18632/oncoscience.333] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 09/23/2016] [Indexed: 12/11/2022] Open
Abstract
The SWI/SNF complex is an important regulator of gene expression that functions by interacting with a diverse array of cellular proteins. The catalytic subunits of SWI/SNF, BRG1 and BRM, are frequently lost alone or concomitantly in a range of different cancer types. This loss abrogates SWI/SNF complex function as well as the functions of proteins that are required for SWI/SNF function, such as RB1 and TP53. Yet while both proteins are known to be dependent on SWI/SNF, we found that BRG1, but not BRM, is functionally linked to RB1, such that loss of BRG1 can directly or indirectly inactivate the RB1 pathway. This newly discovered dependence of RB1 on BRG1 is important because it explains why BRG1 loss can blunt the growth-inhibitory effect of tyrosine kinase inhibitors (TKIs). We also observed that selection for Trp53 mutations occurred in Brm-positive tumors but did not occur in Brm-negative tumors. Hence, these data indicate that, during cancer development, Trp53 is functionally dependent on Brm but not Brg1. Our findings show for the first time the key differences in Brm- and Brg1-specific SWI/SNF complexes and help explain why concomitant loss of Brg1 and Brm frequently occurs in cancer, as well as how their loss impacts cancer development.
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Affiliation(s)
| | - Sudhir K Rai
- Department of Hematology/Oncology, Medicine, University of Florida, Gainesville, FL, USA
| | - Sarah Jb Gramling
- Department of Hematology/Oncology, Medicine, University of Florida, Gainesville, FL, USA
| | - Li Lu
- Department of Hematology/Oncology, Medicine, University of Florida, Gainesville, FL, USA; Department of Pathology, University of Florida, Gainesville, FL, USA
| | - David N Reisman
- Department of Hematology/Oncology, Medicine, University of Florida, Gainesville, FL, USA
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Festuccia N, Gonzalez I, Navarro P. The Epigenetic Paradox of Pluripotent ES Cells. J Mol Biol 2016; 429:1476-1503. [PMID: 27988225 DOI: 10.1016/j.jmb.2016.12.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 12/02/2016] [Accepted: 12/05/2016] [Indexed: 12/15/2022]
Abstract
The propagation and maintenance of gene expression programs are at the foundation of the preservation of cell identity. A large and complex set of epigenetic mechanisms enables the long-term stability and inheritance of transcription states. A key property of authentic epigenetic regulation is being independent from the instructive signals used for its establishment. This makes epigenetic regulation, particularly epigenetic silencing, extremely robust and powerful to lock regulatory states and stabilise cell identity. In line with this, the establishment of epigenetic silencing during development restricts cell potency and maintains the cell fate choices made by transcription factors (TFs). However, how more immature cells that have not yet established their definitive fate maintain their transitory identity without compromising their responsiveness to signalling cues remains unclear. A paradigmatic example is provided by pluripotent embryonic stem (ES) cells derived from a transient population of cells of the blastocyst. Here, we argue that ES cells represent an interesting "epigenetic paradox": even though they are captured in a self-renewing state characterised by extremely efficient maintenance of their identity, which is a typical manifestation of robust epigenetic regulation, they seem not to heavily rely on classical epigenetic mechanisms. Indeed, self-renewal strictly depends on the TFs that previously instructed their undifferentiated identity and relies on a particular signalling-dependent chromatin state where repressive chromatin marks play minor roles. Although this "epigenetic paradox" may underlie their exquisite responsiveness to developmental cues, it suggests that alternative mechanisms to faithfully propagate gene regulatory states might be prevalent in ES cells.
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Affiliation(s)
- Nicola Festuccia
- Epigenetics of Stem Cells, Department of Stem Cell and Developmental Biology, Institut Pasteur, CNRS UMR3738, 25 rue du Docteur Roux, 75015 Paris, France
| | - Inma Gonzalez
- Epigenetics of Stem Cells, Department of Stem Cell and Developmental Biology, Institut Pasteur, CNRS UMR3738, 25 rue du Docteur Roux, 75015 Paris, France
| | - Pablo Navarro
- Epigenetics of Stem Cells, Department of Stem Cell and Developmental Biology, Institut Pasteur, CNRS UMR3738, 25 rue du Docteur Roux, 75015 Paris, France.
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Pathological Ace2-to-Ace enzyme switch in the stressed heart is transcriptionally controlled by the endothelial Brg1-FoxM1 complex. Proc Natl Acad Sci U S A 2016; 113:E5628-35. [PMID: 27601681 DOI: 10.1073/pnas.1525078113] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Genes encoding angiotensin-converting enzymes (Ace and Ace2) are essential for heart function regulation. Cardiac stress enhances Ace, but suppresses Ace2, expression in the heart, leading to a net production of angiotensin II that promotes cardiac hypertrophy and fibrosis. The regulatory mechanism that underlies the Ace2-to-Ace pathological switch, however, is unknown. Here we report that the Brahma-related gene-1 (Brg1) chromatin remodeler and forkhead box M1 (FoxM1) transcription factor cooperate within cardiac (coronary) endothelial cells of pathologically stressed hearts to trigger the Ace2-to-Ace enzyme switch, angiotensin I-to-II conversion, and cardiac hypertrophy. In mice, cardiac stress activates the expression of Brg1 and FoxM1 in endothelial cells. Once activated, Brg1 and FoxM1 form a protein complex on Ace and Ace2 promoters to concurrently activate Ace and repress Ace2, tipping the balance to Ace2 expression with enhanced angiotensin II production, leading to cardiac hypertrophy and fibrosis. Disruption of endothelial Brg1 or FoxM1 or chemical inhibition of FoxM1 abolishes the stress-induced Ace2-to-Ace switch and protects the heart from pathological hypertrophy. In human hypertrophic hearts, BRG1 and FOXM1 expression is also activated in endothelial cells; their expression levels correlate strongly with the ACE/ACE2 ratio, suggesting a conserved mechanism. Our studies demonstrate a molecular interaction of Brg1 and FoxM1 and an endothelial mechanism of modulating Ace/Ace2 ratio for heart failure therapy.
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Takada Y, Fukuda A, Chiba T, Seno H. Brg1 plays an essential role in development and homeostasis of the duodenum through regulation of Notch signaling. Development 2016; 143:3532-3539. [PMID: 27510977 DOI: 10.1242/dev.141549] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 07/28/2016] [Indexed: 12/16/2022]
Abstract
Brg1, a core subunit of the SWI/SNF chromatin remodeling complex, is essential for development and homeostasis of various organs. However, the functional role of Brg1 in intestinal development and homeostasis, and the underlying molecular mechanism, remain unknown. We found that deletion of Brg1 in the mouse intestine resulted in growth impairment and early death associated with abnormal crypt-villous formation, skewed differentiation into secretory lineage cells, markedly increased apoptosis, and stem cell loss in the duodenum. Furthermore, we found that the Notch signaling pathway was dramatically downregulated in Brg1-deficient duodenum. Remarkably, overexpression of the Notch1 intercellular domain (ICD) partially reversed the prognosis of intestinal Brg1 mutant mice. Notch1 ICD overexpression rescued morphogenesis, prevented over-differentiation into secretory lineage cells, and restored apoptosis to normal levels in Brg1-deficient duodenum, although stem cell loss was not rescued. Our data demonstrate that Brg1 plays an essential role in development and homeostasis, including morphogenesis, stem cell differentiation and cell survival in the duodenum. Mechanistically, the rescue of the intestinal Brg1 mutant phenotype by overexpression of the Notch1 ICD indicates that Notch signaling is a key downstream target that mediates the effects of Brg1.
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Affiliation(s)
- Yutaka Takada
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto 6068507, Japan
| | - Akihisa Fukuda
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto 6068507, Japan
| | - Tsutomu Chiba
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto 6068507, Japan
| | - Hiroshi Seno
- Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto 6068507, Japan
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Brg1 Enables Rapid Growth of the Early Embryo by Suppressing Genes That Regulate Apoptosis and Cell Growth Arrest. Mol Cell Biol 2016; 36:1990-2010. [PMID: 27185875 DOI: 10.1128/mcb.01101-15] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 05/02/2016] [Indexed: 11/20/2022] Open
Abstract
SWI/SNF (switching/sucrose nonfermenting)-dependent chromatin remodeling establishes coordinated gene expression programs during development, yet important functional details remain to be elucidated. We show that the Brg1 (Brahma-related gene 1; Smarca4) ATPase is globally expressed at high levels during postimplantation development and its conditional ablation, beginning at gastrulation, results in increased apoptosis, growth retardation, and, ultimately, embryonic death. Global gene expression analysis revealed that genes upregulated in Rosa26CreERT2; Brg1(flox/flox) embryos (here referred to as Brg1(d/d) embryos to describe embryos with deletion of the Brg1(flox/flox) alleles) negatively regulate cell cycle progression and cell growth. In addition, the p53 (Trp53) protein, which is virtually undetectable in early wild-type embryos, accumulated in the Brg1(d/d) embryos and activated the p53-dependent pathways. Using P19 cells, we show that Brg1 and CHD4 (chromodomain helicase DNA binding protein 4) coordinate to control target gene expression. Both proteins physically interact and show a substantial overlap of binding sites at chromatin-accessible regions adjacent to genes differentially expressed in the Brg1(d/d) embryos. Specifically, Brg1 deficiency results in reduced levels of the repressive histone H3 lysine K27 trimethylation (H3K27me3) histone mark and an increase in the amount of open chromatin at the regulatory region of the p53 and p21 (Cdkn1a) genes. These results provide insights into the mechanisms by which Brg1 functions, which is in part via the p53 program, to constrain gene expression and facilitate rapid embryonic growth.
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Jin Y, Ren N, Li S, Fu X, Sun X, Men Y, Xu Z, Zhang J, Xie Y, Xia M, Gao J. Deletion of Brg1 causes abnormal hair cell planer polarity, hair cell anchorage, and scar formation in mouse cochlea. Sci Rep 2016; 6:27124. [PMID: 27255603 PMCID: PMC4891731 DOI: 10.1038/srep27124] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 05/12/2016] [Indexed: 12/28/2022] Open
Abstract
Hair cells (HCs) are mechanosensors that play crucial roles in perceiving sound, acceleration, and fluid motion. The precise architecture of the auditory epithelium and its repair after HC loss is indispensable to the function of organ of Corti (OC). In this study, we showed that Brg1 was highly expressed in auditory HCs. Specific deletion of Brg1 in postnatal HCs resulted in rapid HC degeneration and profound deafness in mice. Further experiments showed that cell-intrinsic polarity of HCs was abolished, docking of outer hair cells (OHCs) by Deiter’s cells (DCs) failed, and scar formation in the reticular lamina was deficient. We demonstrated that Brg1 ablation disrupted the Gαi/Insc/LGN and aPKC asymmetric distributions, without overt effects on the core planer cell polarity (PCP) pathway. We also demonstrated that Brg1-deficient HCs underwent apoptosis, and that leakage in the reticular lamina caused by deficient scar formation shifted the mode of OHC death from apoptosis to necrosis. Together, these data demonstrated a requirement for Brg1 activity in HC development and suggested a role for Brg1 in the proper cellular structure formation of HCs.
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Affiliation(s)
- Yecheng Jin
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Naixia Ren
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Shiwei Li
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Xiaolong Fu
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Xiaoyang Sun
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Yuqin Men
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Zhigang Xu
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Jian Zhang
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Yue Xie
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Ming Xia
- Department of Otolaryngology-Head and Neck Surgery, The Second Hospital of Shandong University, Jinan 250033, China
| | - Jiangang Gao
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
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SMARCA4/Brg1 coordinates genetic and epigenetic networks underlying Shh-type medulloblastoma development. Oncogene 2016; 35:5746-5758. [PMID: 27065321 DOI: 10.1038/onc.2016.108] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 12/15/2015] [Accepted: 01/08/2016] [Indexed: 02/07/2023]
Abstract
Recent large-scale genomic studies have classified medulloblastoma into four subtypes: Wnt, Shh, Group 3 and Group 4. Each is characterized by specific mutations and distinct epigenetic states. Previously, we showed that a chromatin regulator SMARCA4/Brg1 is required for Gli-mediated transcription activation in Sonic hedgehog (Shh) signaling. We report here that Brg1 controls a transcriptional program that specifically regulates Shh-type medulloblastoma growth. Using a mouse model of Shh-type medulloblastoma, we deleted Brg1 in precancerous progenitors and primary or transplanted tumors. Brg1 deletion significantly inhibited tumor formation and progression. Genome-wide expression analyses and binding experiments indicate that Brg1 specifically coordinates with key transcription factors including Gli1, Atoh1 and REST to regulate the expression of both oncogenes and tumor suppressors that are required for medulloblastoma identity and proliferation. Shh-type medulloblastoma displays distinct H3K27me3 properties. We demonstrate that Brg1 modulates activities of H3K27me3 modifiers to regulate the expression of medulloblastoma genes. Brg1-regulated pathways are conserved in human Shh-type medulloblastoma, and Brg1 is important for the growth of a human medulloblastoma cell line. Thus, Brg1 coordinates a genetic and epigenetic network that regulates the transcriptional program underlying the Shh-type medulloblastoma development.
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Matsumoto S, Banine F, Feistel K, Foster S, Xing R, Struve J, Sherman LS. Brg1 directly regulates Olig2 transcription and is required for oligodendrocyte progenitor cell specification. Dev Biol 2016; 413:173-87. [PMID: 27067865 DOI: 10.1016/j.ydbio.2016.04.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 02/28/2016] [Accepted: 04/04/2016] [Indexed: 01/10/2023]
Abstract
The Olig2 basic-helix-loop-helix transcription factor promotes oligodendrocyte specification in early neural progenitor cells (NPCs), including radial glial cells, in part by recruiting SWI/SNF chromatin remodeling complexes to the enhancers of genes involved in oligodendrocyte differentiation. How Olig2 expression is regulated during oligodendrogliogenesis is not clear. Here, we find that the Brg1 subunit of SWI/SNF complexes interacts with a proximal Olig2 promoter and represses Olig2 transcription in the mouse cortex at E14, when oligodendrocyte progenitors (OPCs) are not yet found in this location. Brg1 does not interact with the Olig2 promoter in the E14 ganglionic eminence, where NPCs differentiate into Olig2-positive OPCs. Consistent with these findings, Brg1-null NPCs demonstrate precocious expression of Olig2 in the cortex. However, these cells fail to differentiate into OPCs. We further find that Brg1 is necessary for neuroepithelial-to-radial glial cell transition, but not neuronal differentiation despite a reduction in expression of the pro-neural transcription factor Pax6. Collectively, these and earlier findings support a model whereby Brg1 promotes neurogenic radial glial progenitor cell specification but is dispensable for neuronal differentiation. Concurrently, Brg1 represses Olig2 expression and the specification of OPCs, but is required for OPC differentiation and oligodendrocyte maturation.
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Affiliation(s)
- Steven Matsumoto
- Integrative Biosciences Department, School of Dentistry, Oregon Health & Science University, Portland, OR 97239, USA; Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Ave., Beaverton, OR 97006, USA
| | - Fatima Banine
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Ave., Beaverton, OR 97006, USA
| | - Kerstin Feistel
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Ave., Beaverton, OR 97006, USA
| | - Scott Foster
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Ave., Beaverton, OR 97006, USA
| | - Rubing Xing
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Ave., Beaverton, OR 97006, USA
| | - Jaime Struve
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Ave., Beaverton, OR 97006, USA
| | - Larry S Sherman
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Ave., Beaverton, OR 97006, USA; Department of Cell, Developmental and Cancer Biology, School of Medicine, Oregon Health and Science University, Portland, OR 97239, USA.
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Bultman SJ, Holley DW, G de Ridder G, Pizzo SV, Sidorova TN, Murray KT, Jensen BC, Wang Z, Bevilacqua A, Chen X, Quintana MT, Tannu M, Rosson GB, Pandya K, Willis MS. BRG1 and BRM SWI/SNF ATPases redundantly maintain cardiomyocyte homeostasis by regulating cardiomyocyte mitophagy and mitochondrial dynamics in vivo. Cardiovasc Pathol 2016; 25:258-269. [PMID: 27039070 DOI: 10.1016/j.carpath.2016.02.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 02/24/2016] [Accepted: 02/27/2016] [Indexed: 12/13/2022] Open
Abstract
There has been an increasing recognition that mitochondrial perturbations play a central role in human heart failure. Mitochondrial networks, whose function is to maintain the regulation of mitochondrial biogenesis, autophagy ('mitophagy') and mitochondrial fusion/fission, are new potential therapeutic targets. Yet our understanding of the molecular underpinning of these processes is just emerging. We recently identified a role of the SWI/SNF ATP-dependent chromatin remodeling complexes in the metabolic homeostasis of the adult cardiomyocyte using cardiomyocyte-specific and inducible deletion of the SWI/SNF ATPases BRG1 and BRM in adult mice (Brg1/Brm double mutant mice). To build upon these observations in early altered metabolism, the present study looks at the subsequent alterations in mitochondrial quality control mechanisms in the impaired adult cardiomyocyte. We identified that Brg1/Brm double-mutant mice exhibited increased mitochondrial biogenesis, increases in 'mitophagy', and alterations in mitochondrial fission and fusion that led to small, fragmented mitochondria. Mechanistically, increases in the autophagy and mitophagy-regulated proteins Beclin1 and Bnip3 were identified, paralleling changes seen in human heart failure. Evidence for perturbed cardiac mitochondrial dynamics included decreased mitochondria size, reduced numbers of mitochondria, and an altered expression of genes regulating fusion (Mfn1, Opa1) and fission (Drp1). We also identified cardiac protein amyloid accumulation (aggregated fibrils) during disease progression along with an increase in pre-amyloid oligomers and an upregulated unfolded protein response including increased GRP78, CHOP, and IRE-1 signaling. Together, these findings described a role for BRG1 and BRM in mitochondrial quality control, by regulating mitochondrial number, mitophagy, and mitochondrial dynamics not previously recognized in the adult cardiomyocyte. As critical to the pathogenesis of heart failure, epigenetic mechanisms like SWI/SNF chromatin remodeling seem more intimately linked to cardiac function and mitochondrial quality control mechanisms than previously realized.
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Affiliation(s)
- Scott J Bultman
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Darcy Wood Holley
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | | | | | - Tatiana N Sidorova
- Departments of Medicine and Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Katherine T Murray
- Departments of Medicine and Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Brian C Jensen
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, USA
| | - Zhongjing Wang
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, USA
| | - Ariana Bevilacqua
- Department of Pathology & Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Xin Chen
- Department of Neurosurgery, Shandong Provincial Hospital affiliated to Shandong University, 250021, Jinan, PR China
| | - Megan T Quintana
- Department of Surgery, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Manasi Tannu
- School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Gary B Rosson
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | | | - Monte S Willis
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, USA; Department of Pathology & Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA.
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Chd7 cooperates with Sox10 and regulates the onset of CNS myelination and remyelination. Nat Neurosci 2016; 19:678-689. [PMID: 26928066 PMCID: PMC4846514 DOI: 10.1038/nn.4258] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 02/01/2016] [Indexed: 12/12/2022]
Abstract
Mutations in CHD7, encoding ATP-dependent chromodomain-helicase-DNA-binding protein 7, in CHARGE syndrome leads to multiple congenital anomalies including craniofacial malformations, neurological dysfunction and growth delay. Currently, mechanisms underlying the CNS phenotypes remain poorly understood. Here, we show that Chd7 is a direct transcriptional target of oligodendrogenesis-promoting factors Olig2 and Smarca4/Brg1, and is required for proper onset of CNS myelination and remyelination. Genome-occupancy analyses, coupled with transcriptome profiling, reveal that Chd7 interacts with Sox10 and targets the enhancers of key myelinogenic genes, and identify novel Chd7 targets including bone formation regulators Osterix/Sp7 and Creb3l2, which are also critical for oligodendrocyte maturation. Thus, Chd7 coordinates with Sox10 to regulate the initiation of myelinogenesis and acts as a molecular nexus of regulatory networks that account for the development of a seemingly diverse array of lineages including oligodendrocytes and osteoblasts, pointing to the hitherto previously uncharacterized Chd7 functions in white matter pathogenesis in CHARGE syndrome.
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Padilla-Benavides T, Nasipak BT, Imbalzano AN. Brg1 Controls the Expression of Pax7 to Promote Viability and Proliferation of Mouse Primary Myoblasts. J Cell Physiol 2015; 230:2990-7. [PMID: 26036967 DOI: 10.1002/jcp.25031] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 05/04/2015] [Indexed: 12/29/2022]
Abstract
Brg1 (Brahma-related gene 1) is a catalytic component of the evolutionarily conserved mammalian SWI/SNF ATP-dependent chromatin remodeling enzymes that disrupt histone-DNA contacts on the nucleosome. While the requirement for the SWI/SNF enzymes in cell differentiation has been extensively studied, its role in precursor cell proliferation and survival is not as well defined. Muscle satellite cells constitute the stem cell pool that sustains and regenerates myofibers in adult skeletal muscle. Here, we show that deletion of Brg1 in primary mouse myoblasts derived from muscle satellite cells cultured ex vivo leads to a cell proliferation defect and apoptosis. We determined that Brg1 regulates cell proliferation and survival by controlling chromatin remodeling and activating transcription at the Pax7 promoter, which is expressed during somite development and is required for controlling viability of the satellite cell population. Reintroduction of catalytically active Brg1 or of Pax7 into Brg1-deficient satellite cells rescued the apoptotic phenotype and restored proliferation. These data demonstrate that Brg1 functions as a positive regulator for cellular proliferation and survival of primary myoblasts. Therefore, the regulation of gene expression through Brg1-mediated chromatin remodeling is critical not just for skeletal muscle differentiation but for maintaining the myoblast population as well.
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Affiliation(s)
- Teresita Padilla-Benavides
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Brian T Nasipak
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Anthony N Imbalzano
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts
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50
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Autism-Associated Chromatin Regulator Brg1/SmarcA4 Is Required for Synapse Development and Myocyte Enhancer Factor 2-Mediated Synapse Remodeling. Mol Cell Biol 2015; 36:70-83. [PMID: 26459759 DOI: 10.1128/mcb.00534-15] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 10/05/2015] [Indexed: 11/20/2022] Open
Abstract
Synapse development requires normal neuronal activities and the precise expression of synapse-related genes. Dysregulation of synaptic genes results in neurological diseases such as autism spectrum disorders (ASD). Mutations in genes encoding chromatin-remodeling factor Brg1/SmarcA4 and its associated proteins are the genetic causes of several developmental diseases with neurological defects and autistic symptoms. Recent large-scale genomic studies predicted Brg1/SmarcA4 as one of the key nodes of the ASD gene network. We report that Brg1 deletion in early postnatal hippocampal neurons led to reduced dendritic spine density and maturation and impaired synapse activities. In developing mice, neuronal Brg1 deletion caused severe neurological defects. Gene expression analyses indicated that Brg1 regulates a significant number of genes known to be involved in synapse function and implicated in ASD. We found that Brg1 is required for dendritic spine/synapse elimination mediated by the ASD-associated transcription factor myocyte enhancer factor 2 (MEF2) and that Brg1 regulates the activity-induced expression of a specific subset of genes that overlap significantly with the targets of MEF2. Our analyses showed that Brg1 interacts with MEF2 and that MEF2 is required for Brg1 recruitment to target genes in response to neuron activation. Thus, Brg1 plays important roles in both synapse development/maturation and MEF2-mediated synapse remodeling. Our study reveals specific functions of the epigenetic regulator Brg1 in synapse development and provides insights into its role in neurological diseases such as ASD.
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