Chromatin Organization Regulates Osteogenesis

染色质组织调节成骨

• 批准号: 10540818
• 负责人: Jane B. Lian
• 金额: $ 50.64万
• 依托单位: UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-06 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10540818
• 关键词: Acetylation; Acute; Affect; Aging; Alkaline Phosphatase; Binding; Biological Assay; Bone Development; Bone Formation Stimulation; Bone Regeneration; Bone Surface; Bone Tissue; CCCTC-binding factor; CRISPR/Cas technology; Cell Lineage; Cell Separation; Cells; Chromatin; Chromatin Structure; Chromosome Mapping; Chromosomes; Clustered Regularly Interspaced Short Palindromic Repeats; Competence; Complement; Complex; Control Groups; Data Set; Development; Dimensions; Enhancers; Epigenetic Process; Female; Future; Gene Expression; Gene Expression Regulation; Genes; Genetic Transcription; Genome; Genomic Segment; Genomics; Hi-C; Higher Order Chromatin Structure; Histology; Impairment; Implant; Injections; Intervention; Knowledge; Link; Maps; Mature Bone; Mediating; Mesenchymal Stem Cells; MicroRNAs; Modeling; Modification; Mus; Osteoblasts; Osteogenesis; Outcome; Phenotype; Prevention strategy; Publishing; Regulatory Element; Research; Resolution; Role; Selection Criteria; Specific qualifier value; Supporting Cell; Testing; Therapeutic; Time; Tissues; Transcriptional Regulation; Transplantation; Undifferentiated; bone; bone loss; chromosomal location; clinically relevant; cohort; differential expression; functional genomics; gene network; histone modification; in vivo; in vivo evaluation; male; mouse model; novel; osteoblast differentiation; osteogenic; programs; protein complex; skeletal disorder; stem cells; subcutaneous; transcription factor; transcriptome sequencing; translational applications; treatment strategy

SUMMARY This new R01 builds on discoveries during the R37 period (2008-2018) that established epigenetic mechanisms (miRNAs, histone modifications) regulating osteoblast differentiation. We characterized for the first time a “signature” of specific histone modifications that are associated with dynamic changes in gene expression during the temporal progression of osteogenesis. These histone modifications also predicted “enhancers”, which are critical cis-regulatory elements that contribute to local gene expression. We now propose to examine the recently recognized “super enhancer” domains (SEDs) that include regulatory elements for multiple transcription factors that have emerged as key regulators of cell phenotypes. SEDs function in chromatin organization via long range intra- and inter-chromosomal interactions that coordinate control of gene cohorts responsible for lineage specification and distinct cell identity. Our preliminary studies have identified a subset of SEDs that we now propose are putative “bone-essential super-enhancers” and candidates for the important decision stage of commitment to osteogenesis from MSCs. We hypothesize that super-enhancer domains are differentially activated from the undifferentiated MSC to the osteoblast commitment stage, and function to establish the osteogenic phenotype by coordinately regulating gene networks and contributing to higher order chromatin organization that supports cell identity. Our studies will in: Aim1- analyze the functional effects of prioritized SEDs we have identified related to osteoblastogenesis and mature bone activities through directed inhibition and activation of SEDs using CRISPR/Cas9 in MSCs; Aim 2- determine the chromosomal domains that interact with SEDs to control multiple genes and networks that commit MSCs to the osteoblast phenotype through chromatin organization; and Aim 3- demonstrate in mouse models that using CRISPR activated SEDs in MSCs will stimulate bone formation. Impact: These studies pioneer a new level of gene regulation for MSC lineage commitment to osteogenesis, based on an emerging understanding of SED functions in other tissues but have been minimally studied in bone. By characterizing SED mechanisms related to chromatin organization and stabilization in MSCs, we will discover novel mechanisms of multi-dimensional coordinate control of transcriptional hubs and protein complexes within an SED that is responsible for establishing commitment to the osteoblast phenotype. Importantly, knowledge of the chromatin organization that stabilizes the osteogenic phenotype impacts on future novel treatment strategies for skeletal disorders.

总结