2002 — 2004 |
Boyer, Laurie A |
F32Activity Code Description: To provide postdoctoral research training to individuals to broaden their scientific background and extend their potential for research in specified health-related areas. |
Causal Role For Dnmt1 in C-T Mutations and Tumorigenesis @ Whitehead Institute For Biomedical Res
DESCRIPTION (provided by applicant): The overall objective of this research proposal is to understand the mechanism by which epigenetic processes such as DNA methylation can contribute to neoplasia. We wish to investigate a direct causal role for DNMT1, the major mammalian maintenance DNA (cytosine-5) methyltransferase, in inducing C-T transition mutations similar to that shown for bacterial (cytosine-5) methyltransferases. This will involve the creation of conditional and tissue-specific alleles of DNMT 1 and the generation of transgenic mice and primary murine embryonic fibroblast (MEFs) cell lines using the established Cre/LoxP or Flp/Frt system and standard genetic methods. We will define the role of Dnmt1 in the incidence of point mutations in MEFs harboring the various conditional alleles by performing a quantitative analysis that measures spontaneous and induced mutation frequencies. We will then analyze wild-type and tumor prone mice that contain tissue-specific and conditional alleles of DNMT1 for the incidence of genomic methylation, incidence of point mutations, and tumor formation. These studies may provide a novel paradigm for understanding events that lead to abnormal cellular proliferation.
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0.922 |
2009 — 2014 |
Boyer, Laurie A Bruneau, Benoit Gaetan [⬀] Conklin, Bruce R (co-PI) [⬀] Pollard, Katherine Snowden (co-PI) [⬀] Srivastava, Deepak (co-PI) [⬀] Yamanaka, Shinya (co-PI) [⬀] |
U01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
The Epigenetic Landscape of Heart Development @ J. David Gladstone Institutes
DESCRIPTION (provided by applicant): Congenital heart defects (CHDs) are among the most common and most devastating birth defects in humans. Networks of transcription factors regulate cardiac cell fate and morphogenesis, and dominant mutations in transcription factor genes lead to most instances of inherited CHD. The mechanisms underlying CHDs that result from disruption of these networks remain to be identified, but regulation of gene expression within a relatively narrow developmental window is clearly essential for normal cardiac morphogenesis. In addition to transcription factors, epigenetic regulation via histone modifications, chromatin remodeling, and non-coding RNAs have key roles in modulating gene expression programs. Elucidating on a genome scale the physical and functional interactions between transcription factors and epigenetic regulators will considerably enhance our understanding of the control of heart development and will have important implications for understanding the mechanistic basis of CHDs. We propose a project as part of the NHLBI Heart Development consortium to provide an integrated epigenetic landscape for heart development, with a focus on CHD-related genes. We propose three major aims. Aim 1: Define genome-wide occupancy maps of transcription factors with known roles in cardiac development and human disease, and epigenetic regulators of transcription, in differentiating cardiomyocytes. Aim 2: Define the global function of transcriptional and epigenetic regulation in heart development and congenital heart disease. We will examine the effect of loss of function of cardiac transcription factors on epigenetic regulation, and alterations in epigenetic regulation in disease-specific induced pluripotent cells from CHD patients. We will also evaluate the global role of histone modifications in mouse heart development. Aim 3;Integrate microRNA expression and function into the regulatory networks governing cardiac development. High-resolution occupancy maps from Aims 1 and 2 will be analyzed specifically for miRNA promoter occupancy and combined with quantitative sequencing of miRNAs in differentiating cardiomyocytes. We will study the function of highly altered miRNAs, specifically those that target disease-causing cardiac transcription factors. Our studies will yield an important and transformative epigenetic atlas of heart development, which will link for the first time transcriptional and epigenetic regulators in a comprehensive network that will illuminate mechanisms underlying CHDs. RELEVANCE (See instructions): The proposed project will for the first time allow a new understanding of the gene networks that underlie congenital heart disease. Congenital heart disease is the most serious childhood illness, affecting 1% of children, and leading to significant mortality and long-term illness. However the underlying causes of these diseases are not understood. Our project will link the so-called "epigenetic regulators" that control how genes are turned on or off, to congenital heart disease, bringing new important insights into these diseases.
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0.901 |
2018 — 2021 |
Boyer, Laurie A |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Investigating the Role of H2a.Z Dynamics in Regulating Cardiac Lineage Commitment @ Massachusetts Institute of Technology
SUMMARY Over the past 25 years, genetic studies in model systems, such as mouse, have revealed highly conserved transcription factors (TFs) controlling human embryonic heart development. Although these studies have identified causal mutations that contribute to congenital heart defects (CHD), we still do not know the molecular causes associated with >80% of cases. Chromatin modulation acts to coordinate developmental signals and TF activity, and disruption of chromatin structure is emerging as a major contributor to CHD, yet its roles are least understood. This gap in our knowledge hinders our understanding of heart development and CHD, slowing the development of breakthrough drugs to treat these devastating malformations. Our proposal integrates innovative experimental and computational approaches to test the hypothesis that H2A.Z incorporation by specific ATP-dependent remodeling complexes regulates critical cardiac gene ciruits during lineage commitment. Notably, H2A.Z as well as components of its cognate remodeling complexes have been linked to heart development and disease, however, their roles are poorly understood. Our extensive preliminary work demonstrates that H2A.Z is enriched at promoter nucleosomes and acts as a molecular rheostat to control transcriptional output by coordinating with histone ?readers? and ?writers?, supporting our goal to dissect how these pathways functionally coordinate to regulate cardiac lineage commitment. Thus, we expect that the impact of this proposal is several fold: 1) Dissecting how H2A.Z dynamics regulates cardiac gene circuits represents a novel pathway for understanding how chromatin coordinates cardiac gene regulatory networks. 2) Our approach will contribute new tools and insights into the pathways that are disrupted in congenital heart defects (CHD). 3) Transcriptional control of embryonic heart development shares many features with induction of pathological gene expression in response to injury or disease, thus, our study opens the door for identifying potential new therapeutic targets for both CHD as well as pathological cardiac hypertrophy. 4) Our proposed aims will generate large-scale, genomic data in mouse cardiac cell types that can be immediately leveraged by the scientific community to enable additional discoveries. Finally, 5) the recent association of genetic variants within conserved genes coding for Chromatin Remodelers in patients with congenital and acquired heart defects indicates that our work will most certainly impact human health.
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