Cytosolic DNA sensing instructs resident macrophage vitality and organismal longevity

项目摘要 与年龄相关的慢性炎症被认为与称为 衰老及衰老相关分泌表型(SASP)。最近的研究表明， 用环-二-GMP-AMP-合成酶检测衰老细胞胞浆染色质或DNA损伤 (CGAS)和干扰素基因刺激物(STING)调控SASP。根据这些报道，它是 推测cGAS/STING信号驱动与年龄相关的病理。然而，这些研究主要是 重点了解cGAS/STING依赖的衰老在成纤维细胞中的作用。作为成纤维细胞 只代表了在组织中发现的一小部分细胞，我们试图通过探索 CGAS/STING信号在多个组织的时间和生理变化中的作用 衰老。使用单细胞rna测序，我们注意到在所有被测试的组织中，衰老的主要特征。 (肾、肺、心、肝和脑)。这些特征延伸到成纤维细胞和非成纤维细胞基质细胞。 如内皮细胞和上皮细胞，也包括组织驻留巨噬细胞(TRMS)。TRM对以下方面至关重要 最佳的器官功能和修复。CGAS或STING的丢失会影响TRM在体内和体外的活性， 使它们易于细胞死亡。此外，我们还表明，内源性逆转录因子(ERE)是一种已被证实的 CGAS/STING激活的配体在TRMS中表达，对正常的组织中心功能至关重要 TRMS。最后，与之前研究的预期相反，失去cGAS或STIN会导致 寿命显著缩短，外周炎症性征象明显增多。基于这些范例 改变发现，我们认为cGAS/STING信号平衡了衰老的保护作用 其病理作用是通过细胞特异性作用实现的。因此，我们的广泛目标是了解细胞特有的 CGAS/STING信号在生物衰老中的作用。我们的具体目标将有条不紊地解决这一问题 目的通过对TRMS的研究，探讨TRMS的特点。鉴于DNA传感在区分端点方面发挥的关键作用，如 无论是诱导衰老还是细胞存活，配体的独特性质可能在细胞命运决定中发挥作用。 因此，我们将首先确定ERE在塑造TRM生存和功能方面所起的作用，以及它们如何 CGAS/STING通路因子参与其作用(Aim1)。然后我们的目标是澄清如何 CGAS/STING缺乏影响TRMS的活力，使其易于细胞死亡(AIM2)。最后，我们会 确定cGAS/STING信号的TRM固有缺陷是否可以概括组织功能障碍和 全球cGAS/刺痛缺陷小鼠的寿命受损(Aim3)。这些目标将利用 尖端和创新的工具，如单细胞空间多组学(面向空间的同步 整个组织的蛋白质组学和转录组分析)、多模式CITE-SEQ(表型分析和 具有单细胞分辨率的转录学)和强大的遗传工具。考虑到大规模的治疗推动 以癌症、几种自身免疫性疾病和现在的衰老为目标，我们建议的研究包括 迫切需要充分理解长期修改这一途径的影响。

Project Summary Age-associated chronic inflammation is thought to be directly linked to the cellular processes termed senescence and senescence associated secretory phenotype (SASP). Recent studies suggest that the sensing of cytosolic chromatin or damaged DNA in senescent cells by the cyclic-di-GMP-AMP-synthase (cGAS) and Stimulator of Interferon Genes (STING) regulate the SASP. Based on these reports, it is presumed that cGAS/STING signaling drives age-associated pathology. However, these studies primarily focused on understanding the role of the cGAS/STING dependent senescence in fibroblasts. As fibroblasts represent only a small sliver of the cells found in tissues, we sought to extend these studies by exploring the contribution of cGAS/STING-signaling to changes in multiple tissues during chronological and physiological aging. Using single-cell RNA-sequencing, we note predominant signatures of senescence in all tissues tested (kidneys, lungs, heart, liver and brain). These signatures extend to fibroblasts and non-fibroblast stromal cells like endothelial and epithelial cells, but also to tissue-resident macrophages (TRMs). TRMs are critical for optimal organ function and repair. The loss of cGAS or STING impacts TRM viability in vivo and ex vivo, predisposing them to cell-death. Furthermore, we show that endogenous retroelements (EREs), a proven ligand for cGAS/STING activation, are expressed in TRMs and critical for normal tissue-centric functions of TRMs. Finally, contrary to expectations based on previous studies, the loss of cGAS or STING leads to significantly shorter lifespans and greater peripheral inflammatory signature. Based on these paradigm shifting findings, we propose that cGAS/STING signaling balances the protective effects of senescence with its pathological effects through cell-specific roles. Our broad objective is thus, to understand the cell-specific contribution of cGAS/STING signaling to organismal aging. Our specific aims will methodically tackle this objective by focusing on TRMs. Given the critical role DNA-sensing plays in discriminating endpoints like senescence induction or cell-survival, the unique nature of ligands may play a role in cell-fate decisions. Thus, we will first ascertain the role EREs play in shaping TRM survival and function and how their engagement of the cGAS/STING pathway factors into their role (Aim1). We then aim to clarify how cGAS/STING deficiency impacts the vitality of TRMs, predisposing them to cell-death (Aim2). Finally, we will determine if a TRM-intrinsic deficiency of cGAS/STING signaling can recapitulate the tissue dysfunction and compromised lifespans seen in mice with global cGAS/STING deficiency (Aim3). These aims will utilize cutting-edge and innovative tools like single-cell spatial multi-omics (a spatially oriented simultaneous profiling of proteomics and transcriptomics in whole tissues), multi-modal CITE-seq (phenotypic profiling and transcriptomics with single-cell resolution) and powerful genetic tools. Given the massive therapeutic push to target this pathway in cancer, several autoimmune diseases and now aging, our proposed studies are urgently needed to fully comprehend the impact of modifying this pathway long-term.