Role of a novel PGC-1α isoform in gene transcription

新型 PGC-1α 亚型在基因转录中的作用

基本信息

批准号：
10525004
负责人：
Xavier Rambout
金额：
$ 19.25万
依托单位：
UNIVERSITY OF ROCHESTER
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-08-01 至 2024-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10525004
关键词：
Adhesions Age Aging Alleles Amino Acid Sequence Amino Acids Anti-Inflammatory Agents Antibodies Antisense Oligonucleotides Area Atherosclerosis Binding Biological Assay Blood Vessels C-terminal CCL2 gene CCL7 gene CCL8 gene CRISPR/Cas technology Cardiac Cardiac development Cardiovascular Diseases Cause of Death Cellular Metabolic Process Chemotactic Factors Chromatin Complementary DNA Data Development Disease Dystrophin Endothelial Cells Endothelium Engineering Exons Female Gene Expression Regulation Genes Genetic Transcription In Vitro Individual Infiltration Inflammation Inflammatory Inflammatory Response Knock-out Liquid Chromatography MAP Kinase Gene Malignant Neoplasms Mammalian Cell Maps Messenger RNA Metabolic Metabolism Modeling Monocyte Chemoattractant Proteins Mus Muscle Mutate Myoblasts Names Nucleotides PPAR gamma Phenocopy Plasma Play Polymerase Chain Reaction Premature aging syndrome Production Protein Isoforms Proteins RNA RNA Cap-Binding Proteins RNA Polymerase II RNA Splicing RNA-Binding Proteins Regulation Reporting Research Research Personnel Resolution Risk Risk Factors Role Running Signal Transduction Skeletal Muscle Small Interfering RNA Stress Structure Testing Tissues Transactivation Transcript Transcription Coactivator Transcriptional Regulation Variant alpha helix base career chemokine coronary fibrosis cytokine design functional loss heart function in vivo knock-down mRNA Precursor male migration monocyte mouse model novel novel therapeutics physiologic stressor promoter recruit response sex systemic inflammatory response tandem mass spectrometry transcription factor transcriptome sequencing

项目摘要

Peroxisome proliferator-activated receptor gamma co-activator 1α (PGC-1α) is a transcriptional coactivator that is critical for the metabolic adaptation of mammalian cells to diverse physiological stresses. In addition to this well-described function in the control of cell metabolism, the number of reports describing a protective role for PGC-1α against inflammation is on the rise. I report here a novel stress-dependent pro-inflammatory PGC-1α variant that I have identified in vitro in C2C12 mouse myoblasts and in vivo in mouse skeletal muscle. My unpublished results indicate that, compared to the canonical PGC-1α isoform (also known as PGC-1α(1)), the structure of this novel 72-kDa PGC-1α isoform, which I will call PGC-1α(72), is typified by its lack of the C-terminal 15 amino acids. The deleted C-terminal sequence encompasses a 9-amino-acid alpha helix that I previously reported to be essential for PGC-1α(1) to bind to the cap-binding protein (CBP)80 and to transactivate pro-myogenic PGC-1α-dependent genes. In contrast to PGC-1α(1), PGC-1α(72) lacks the CBP80-binding motif (CBM) and, as my data indicate, activates the transcription of pro-inflammatory genes. In the first aim of my research strategy, I propose to use C2C12 myoblasts to fully characterize the sequence of this novel PGC-1α(72) isoform, identify those transcription factors and RNA-binding proteins that regulate its expression in response to stress, and comprehensively determine the transcriptional network that it activates. In the second aim, I will take advantage of my finding that functional inhibition of the PGC-1α CBM phenocopies PGC-1α(72)-dependent expression of pro-inflammatory chemoattractants such as the chemokine CCL2. Elevated CCL2 plasma levels, which are observed with aging, have been recognized as important risk factors for numerous inflammatory diseases, including cardiac fibrosis, atherosclerosis and cancers. Mechanistically, CCL2 has been found to function in monocyte recruitment onto the endothelium of blood vessels and in monocyte infiltration into inflamed tissues. I will breed our newly characterized PGC-1αCBMmut mice with the Dystrophin-deficient Dmdmdx muscle inflammatory and premature aging mouse model and use derived primary myoblasts to infer the functional consequences of PGC-1α(72) expression, in particular those attributable to its lacking the CBM, to inflammation. In particular, I will determine how PGC-1αCBMmut triggers the CCL2-dependent recruitment of monocytes onto endothelial cells, their infiltration into cardiac tissues, and development of cardiac fibrosis in aging mice as a function of sex, i.e. in males vs. females. I view demonstrating the contribution of PGC-1αCBMmut to cardiac fibrosis as a proof of concept. It will provide fertile grounds to study the function of skeletal muscle PGC-1α(72) in the development of other aging- related inflammatory diseases. I hypothesize that understanding PGC-1α(72)-dependent gene regulation and its consequences to the development of inflammatory diseases will facilitate the development of new therapeutics, such as synthetic antisense oligonucleotides regulating splicing of PGC-1α pre-mRNA.

过氧化物酶体增殖物激活受体 γ 共激活剂 1α (PGC-1α) 是一种转录共激活剂，除此之外，对于哺乳动物细胞对不同生理应激的代谢适应至关重要。详细描述了控制细胞代谢的功能，描述了细胞代谢保护作用的报告数量 PGC-1α 对抗炎症的能力正在上升，我在这里报告了一种新型的应激依赖性促炎 PGC-1α。我在体外 C2C12 小鼠成肌细胞和体内小鼠骨骼肌中发现了这种变异。我未发表的结果表明，与规范的 PGC-1α 同工型（也称为 PGC-1α(1))，这种新型 72-kDa PGC-1α 亚型的结构，我将其称为 PGC-1α(72)，其典型特征是缺少 C 端 15 个氨基酸。删除的 C 端序列包含 9 个氨基酸 α。我之前报道过的螺旋对于 PGC-1α(1) 结合帽结合蛋白 (CBP)80 和反式激活促肌生成 PGC-1α 依赖性基因与 PGC-1α(1) 相比，PGC-1α(72) 缺乏正如我的数据所示，CBP80 结合基序 (CBM) 会激活促炎基因的转录。我的研究策略的第一个目标是，我建议使用 C2C12 成肌细胞来充分表征这种新的 PGC-1α(72) 亚型，鉴定了调节其的转录因子和 RNA 结合蛋白应激反应中的表达，并综合确定其激活的转录网络。在第二个目标中，我将利用我的发现，即 PGC-1α CBM 的功能抑制表型复制 PGC-1α(72) 依赖性促炎趋化因子（例如趋化因子）的表达随着年龄的增长，CCL2 血浆水平升高，已被认为是重要的风险。许多炎症性疾病的因素，包括心脏纤维化、动脉粥样硬化和癌症。从机制上讲，CCL2 已被发现在单核细胞募集到血液内皮细胞中发挥作用我将培育我们新鉴定的 PGC-1αCBMmut。具有肌营养不良蛋白缺陷 Dmdmdx 肌肉炎症和早衰小鼠模型的小鼠及其用途衍生的原代成肌细胞来推断 PGC-1α(72) 表达的功能后果，特别是那些由于其缺乏 CBM，特别是炎症，我将确定 PGC-1αCBMmut 如何触发。 CCL2依赖性单核细胞募集到内皮细胞上、它们浸润到心脏组织中，以及衰老小鼠心脏纤维化的发展与性别有关，即雄性与雌性。我认为证明 PGC-1αCBMmut 对心脏纤维化的贡献是一个概念证明。为研究骨骼肌 PGC-1α(72) 在其他衰老发展中的功能提供了肥沃的基础我了解PGC-1α(72)依赖性基因调控及其相关的炎症性疾病。对炎症性疾病发展的影响将促进新疗法的开发，例如调节 PGC-1α pre-mRNA 剪接的合成反义寡核苷酸。