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Klein DC, Lardo SM, Hainer SJ. The ncBAF Complex Regulates Transcription in AML Through H3K27ac Sensing by BRD9. CANCER RESEARCH COMMUNICATIONS 2024; 4:237-252. [PMID: 38126767 PMCID: PMC10831031 DOI: 10.1158/2767-9764.crc-23-0382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/02/2023] [Accepted: 12/13/2023] [Indexed: 12/23/2023]
Abstract
The non-canonical BAF complex (ncBAF) subunit BRD9 is essential for acute myeloid leukemia (AML) cell viability but has an unclear role in leukemogenesis. Because BRD9 is required for ncBAF complex assembly through its DUF3512 domain, precise bromodomain inhibition is necessary to parse the role of BRD9 as a transcriptional regulator from that of a scaffolding protein. To understand the role of BRD9 bromodomain function in regulating AML, we selected a panel of five AML cell lines with distinct driver mutations, disease classifications, and genomic aberrations and subjected these cells to short-term BRD9 bromodomain inhibition. We examined the bromodomain-dependent growth of these cell lines, identifying a dependency in AML cell lines but not HEK293T cells. To define a mechanism through which BRD9 maintains AML cell survival, we examined nascent transcription, chromatin accessibility, and ncBAF complex binding genome-wide after bromodomain inhibition. We identified extensive regulation of transcription by BRD9 bromodomain activity, including repression of myeloid maturation factors and tumor suppressor genes, while standard AML chemotherapy targets were repressed by inhibition of the BRD9 bromodomain. BRD9 bromodomain activity maintained accessible chromatin at both gene promoters and gene-distal putative enhancer regions, in a manner that qualitatively correlated with enrichment of BRD9 binding. Furthermore, we identified reduced chromatin accessibility at GATA, ETS, and AP-1 motifs and increased chromatin accessibility at SNAIL-, HIC-, and TP53-recognized motifs after BRD9 inhibition. These data suggest a role for BRD9 in regulating AML cell differentiation through modulation of accessibility at hematopoietic transcription factor binding sites. SIGNIFICANCE The bromodomain-containing protein BRD9 is essential for AML cell viability, but it is unclear whether this requirement is due to the protein's role as an epigenetic reader. We inhibited this activity and identified altered gene-distal chromatin regulation and transcription consistent with a more mature myeloid cell state.
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Affiliation(s)
- David C. Klein
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Santana M. Lardo
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Sarah J. Hainer
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
- UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania
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Wei H, Wu X, Withrow J, Cuevas-Diaz Duran R, Singh S, Chaboub LS, Rakshit J, Mejia J, Rolfe A, Herrera JJ, Horner PJ, Wu JQ. Glial progenitor heterogeneity and key regulators revealed by single-cell RNA sequencing provide insight to regeneration in spinal cord injury. Cell Rep 2023; 42:112486. [PMID: 37149868 PMCID: PMC10511029 DOI: 10.1016/j.celrep.2023.112486] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 02/12/2023] [Accepted: 04/22/2023] [Indexed: 05/09/2023] Open
Abstract
Recent studies have revealed the heterogeneous nature of astrocytes; however, how diverse constituents of astrocyte-lineage cells are regulated in adult spinal cord after injury and contribute to regeneration remains elusive. We perform single-cell RNA sequencing of GFAP-expressing cells from sub-chronic spinal cord injury models and identify and compare with the subpopulations in acute-stage data. We find subpopulations with distinct functional enrichment and their identities defined by subpopulation-specific transcription factors and regulons. Immunohistochemistry, RNAscope experiments, and quantification by stereology verify the molecular signature, location, and morphology of potential resident neural progenitors or neural stem cells in the adult spinal cord before and after injury and uncover the populations of the intermediate cells enriched in neuronal genes that could potentially transition into other subpopulations. This study has expanded the knowledge of the heterogeneity and cell state transition of glial progenitors in adult spinal cord before and after injury.
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Affiliation(s)
- Haichao Wei
- The Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX 77030, USA; Center for Stem Cell and Regenerative Medicine, UT Brown Foundation Institute of Molecular Medicine, Houston, TX 77030, USA
| | - Xizi Wu
- The Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX 77030, USA; Center for Stem Cell and Regenerative Medicine, UT Brown Foundation Institute of Molecular Medicine, Houston, TX 77030, USA
| | - Joseph Withrow
- The Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX 77030, USA
| | - Raquel Cuevas-Diaz Duran
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, Nuevo León 64710, Mexico
| | - Simranjit Singh
- The Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX 77030, USA; Center for Stem Cell and Regenerative Medicine, UT Brown Foundation Institute of Molecular Medicine, Houston, TX 77030, USA
| | - Lesley S Chaboub
- Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Jyotirmoy Rakshit
- The Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX 77030, USA; Center for Stem Cell and Regenerative Medicine, UT Brown Foundation Institute of Molecular Medicine, Houston, TX 77030, USA
| | - Julio Mejia
- Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Andrew Rolfe
- The Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX 77030, USA; Center for Stem Cell and Regenerative Medicine, UT Brown Foundation Institute of Molecular Medicine, Houston, TX 77030, USA
| | - Juan J Herrera
- Department of Diagnostic and Interventional Imaging, McGovern Medical School, UTHealth, Houston, TX 77030, USA
| | - Philip J Horner
- Center for Neuroregeneration, Department of Neurosurgery, Houston Methodist Research Institute, Houston, TX 77030, USA.
| | - Jia Qian Wu
- The Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX 77030, USA; Center for Stem Cell and Regenerative Medicine, UT Brown Foundation Institute of Molecular Medicine, Houston, TX 77030, USA; MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA.
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Hao Shi, Yan KK, Ding L, Qian C, Chi H, Yu J. Network Approaches for Dissecting the Immune System. iScience 2020; 23:101354. [PMID: 32717640 PMCID: PMC7390880 DOI: 10.1016/j.isci.2020.101354] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 06/21/2020] [Accepted: 07/08/2020] [Indexed: 02/06/2023] Open
Abstract
The immune system is a complex biological network composed of hierarchically organized genes, proteins, and cellular components that combat external pathogens and monitor the onset of internal disease. To meet and ultimately defeat these challenges, the immune system orchestrates an exquisitely complex interplay of numerous cells, often with highly specialized functions, in a tissue-specific manner. One of the major methodologies of systems immunology is to measure quantitatively the components and interaction levels in the immunologic networks to construct a computational network and predict the response of the components to perturbations. The recent advances in high-throughput sequencing techniques have provided us with a powerful approach to dissecting the complexity of the immune system. Here we summarize the latest progress in integrating omics data and network approaches to construct networks and to infer the underlying signaling and transcriptional landscape, as well as cell-cell communication, in the immune system, with a focus on hematopoiesis, adaptive immunity, and tumor immunology. Understanding the network regulation of immune cells has provided new insights into immune homeostasis and disease, with important therapeutic implications for inflammation, cancer, and other immune-mediated disorders.
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Affiliation(s)
- Hao Shi
- Departments of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Koon-Kiu Yan
- Departments of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Liang Ding
- Departments of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Chenxi Qian
- Departments of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Hongbo Chi
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jiyang Yu
- Departments of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
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