Cytosolic DNA is the Link Between Genomic Instability and Cardiovascular Aging

细胞质 DNA 是基因组不稳定性与心血管衰老之间的联系

• 批准号: 10722123
• 负责人: Ali J Marian
• 金额: $ 61.57万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-15 至 2028-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10722123
• 关键词: Aging; Antibodies; Attenuated; Autophagocytosis; Biological Process; CCCTC-binding factor; Cardiac; Cardiac Myocytes; Cardiovascular system; Cell Aging; Cell Death; Cell Nucleus; Cells; Code; Cytoplasm; Cytosol; DNA; DNA Double Strand Break; DNA Transposable Elements; Defect; Endothelial Cells; Epigenetic Process; Event; Fibroblasts; Fibrosis; Gene Expression; Genes; Genetic; Genome Stability; Genomic Instability; Goals; Heart; Histone Deacetylase; Human; IRF3 gene; Impairment; Inflammation; Inflammatory; Knock-in; Lamin Type A; Length; Link; Logic; Maps; Mechanics; Methylation; Mitochondria; Mitochondrial DNA; Molecular; Morbidity - disease rate; Mutation; NF-kappa B; Nuclear; Nuclear Envelope; Organ; Organism; Pathogenesis; Pathway interactions; Phenotype; Premature aging syndrome; Proteins; Resolution; Role; STING1 gene; Sirtuins; Site; Source; Spliced Genes; TBK1 gene; Testing; Transcription Initiation Site; Wild Type Mouse; age related; cell type; chromatin immunoprecipitation; cohesin; cytokine; design; detection of nutrient; env Gene Products; genome integrity; genome-wide; heart cell; heart function; insight; mortality; mouse model; normal aging; premature; prototype; repaired; senescence; stem cell self renewal; telomere; transcriptome sequencing

Premature aging syndromes in laminopathies caused by mutations in the LMNA gene, encoding nuclear envelope protein lamin A/C (LMNA), are the prototypic examples of genomic instability, which is a hallmark of “normal” aging. Cardiovascular involvement is the cardinal phenotype and the major cause of mortality and morbidity. The pathogenesis of laminopathies and “normal” aging share several common mechanisms. LMNA regulates mitochondrial function, telomere length, nutrient sensing, stem cell regeneration, and autophagy, which are the classic hallmarks of “normal aging”. LMNA expression is reduced in “normal” aging. A similar set of nuclear defects are observed in “normal” aging and laminopathies. LMNA also regulates several epigenetic regulators of aging, including sirtuins and histone deacetylases. Furthermore, LMNA is essential for genomic instability and induction and repair of the double-stranded DNA breaks (DSBs) as well as the mechanical integrity of the nuclear membrane. These mechanisms are also the core mechanisms of “normal” aging. We have shown that the cytosolic DNA (CyDNA)-sensing proteins CGAS/STING1 are induced and their downstream effectors TBK1, IRF3, and NFKB are activated, and the senescence-associated secretory phenotype (SASP) is expressed in the human hearts and mouse models of laminopathies. We also have identified and defined the LMNA-associated domains (LADs) in human cardiac myocytes (CMs) and have shown that LADs are shifted in laminopathies and regulate CpG methylation and gene expression. Moreover, we have identified 711 DSBs (q<0.05) in the nDNA in the LMNA-deficient as compared to the wild-type (WT) CMs by END-Sequencing (END-Seq). DSBs show a preponderance toward the protein-coding genes, which is consistent with the role of the LMNA in defining the boundaries of TADs and TOP2B processing. Furthermore, we have shown that deletion of the Mb21l1 gene, encoding CGAS, attenuates the phenotype in a mouse model of cardiac laminopathies. Therefore, we logic that studying premature aging in laminopathies would provide insights into the mechanisms that are shared with “normal” aging. The large effect sizes of the LMNA mutations would provide a better resolution in discerning the deranged hallmarks of aging than the “normal” aging, whereby numerous determinants, each with a small effect size, interact stochastically to induce aging. Thus, we propose to identify and characterize the genome-wide DSBs in CMs, cardiac fibroblasts (CFs), and endothelial cells (ECs) in laminopathies and the old WT mice by END-Seq, the former because of the involvement of multiple cell types in laminopathies and the latter to assess the extension of the findings in laminopathies to “normal” aging. Likewise, we propose to identify and characterize the sources of the CyDNA in CMs, CFs, and ECs in laminopathies by CGAS ChIP-Seq. Moreover, we propose to determine the effects of genetic blockade of the STING1 on selected hallmarks of aging and cardiac phenotype in laminopathies. The findings are expected to provide insights into the molecular basis of premature CV aging in laminopathies and likely the hallmarks of “normal” aging.

由编码核的 LMNA 基因突变引起的核纤层蛋白病中的过早衰老综合征 包膜蛋白核纤层蛋白 A/C (LMNA) 是基因组不稳定性的典型例子，这是基因组不稳定的标志 “正常”衰老是主要表型，也是死亡和死亡的主要原因。 核纤层蛋白病和“正常”衰老的发病机制有几个共同的机制。 调节线粒体功能、端粒长度、营养感应、干细胞再生和自噬， 是“正常衰老”的典型特征。 在“正常”衰老中观察到核缺陷，LMNA 也调节多种表观遗传。 衰老调节因子，包括去乙酰化酶和组蛋白脱乙酰酶，此外，LMNA 对于基因组至关重要。 双链 DNA 断裂 (DSB) 的不稳定性、诱导和修复以及机械完整性 这些机制也是“正常”衰老的核心机制。 我们已经证明胞质 DNA (CyDNA) 感应蛋白 CGAS/STING1 被诱导，并且它们的 下游效应子 TBK1、IRF3 和 NFKB 被激活，衰老相关的分泌 表型（SASP）在人类心脏和小鼠核纤层蛋白病模型中也有表达。 识别并定义了人类心肌细胞 (CM) 中的 LMNA 相关结构域 (LAD)，并显示 LAD 在核纤层蛋白病中发生转移并调节 CpG 甲基化和基因表达。 与野生型 (WT) CM 相比，LMNA 缺陷的 nDNA 中鉴定出了 711 个 DSB (q<0.05) END 测序 (END-Seq) 显示蛋白质编码基因占优势，这是一致的。 LMNA 在定义 TAD 和 TOP2B 处理的边界方面的作用此外，我们还有。 研究表明，编码 CGAS 的 Mb21l1 基因的缺失会减弱小鼠心脏病模型的表型。 因此，我们认为研究核纤层蛋白病的过早衰老将有助于深入了解核纤层蛋白病。 LMNA 突变的巨大效应将提供与“正常”衰老相同的机制。 与“正常”衰老相比，在识别衰老的紊乱特征方面有更好的解决方案，因此许多 每个影响较小的决定因素随机相互作用以诱导衰老。 并表征了 CM、心脏成纤维细胞 (CF) 和内皮细胞 (EC) 中的全基因组 DSB 核纤层蛋白病和 END-Seq 的老 WT 小鼠，前者是因为多种细胞类型参与 核纤层蛋白病和后者评估核纤层蛋白病的研究结果扩展到“正常”衰老。 我们建议通过以下方法来识别和表征核纤层蛋白病中 CM、CF 和 EC 中 CyDNA 的来源： 此外，我们建议确定 STING1 的基因封锁对选定的影响。 这些发现有望为核纤层蛋白病的衰老和心脏表型的标志提供见解。 核纤层蛋白病中CV过早衰老的分子基础，也可能是“正常”衰老的标志。