Intraarticular microbial DNA as a novel mediator of osteoarthritis

项目概要/摘要 拟议研究的目的是更好地了解软骨微生物 DNA 模式是如何变化的 已确定，以及它们与骨关节炎 (OA) 发病机制和进展的关系。先前发表 研究概述了肠道微生物组随着衰老而发生的促炎症变化，但尚未开展任何工作 旨在检查肠道和/或软骨微生物组、炎症和表观遗传学如何交叉 与办公自动化。我们的实验室之前详细检查了软骨和软骨内的表观遗传变化 与 OA 发展相关的软骨下骨，我们最近检查了表观遗传变化 人类 OA 患者的外周血细胞中与快速 OA 风险增加相关 进展。我们的首要目标是确定软骨微生物 DNA 模式是否源自 肠道微生物组。为此，我们将用年轻小鼠的微生物群填充无菌小鼠的肠道微生物群 然后对 OA 敏感的 C57BL6/J (B6) 小鼠确定预先指定的软骨微生物 DNA 模式 接种后的时间点。如果成功，我们将继续测试盲肠微生物群的变化如何， 与衰老和肥胖等 OA 危险因素相关的软骨微生物群的变化反映了这一点 简介。此外，我们将确定是否可以将已经建立的软骨微生物组模式 通过改变肠道微生物组来改变。我们的第二个目标将确定软骨微生物 DNA 是否 足以改变小鼠患 OA 的风险。为此，我们将注射从 将人类 OA 患者和健康对照者植入无菌小鼠的膝关节，然后通过破坏 内侧半月板（DMM）手术并测量组织病理学结果。如果成功，我们将继续 通过 CyTOF 确定局部和全身炎症细胞群的变化，通过 Bioplex 测定以及关节内注射后全基因组水平的表观遗传和转录组变化 微生物 DNA 传递。拟议的工作很重要，因为我们还没有完全了解如何 非遗传性 OA 风险因素会增加 OA 风险，我们也不了解微生物组如何影响 OA 风险。 我们的工作在使用无菌小鼠微生物组移植来评估 OA 和 使用尖端的 CyTOF 和表观遗传分析。最后，我们将首先评估肠道是否 微生物组移植可用作预防 OA 的治疗剂。我们的提案可能会成功 OA 衰老研究的新途径，并可能为 OA 提供新的治疗策略。

Project Summary / Abstract The objective of the proposed research is to better understand how cartilage microbial DNA patterns are established, and how these relate to osteoarthritis (OA) pathogenesis and progression. Previously published studies have outlined both gut microbiome pro-inflammatory changes with aging generally, but no work has yet been performed to examine how the gut and/or cartilage microbiomes, inflammation, and epigenetics intersect with OA. Our laboratory has previously examined in detail the epigenetic changes within cartilage and subchondral bone that are associated with OA development, and we have recently examined epigenetic changes within peripheral blood cells of human OA patients which are associated with increased risk of rapid OA progression. Our first Aim is to determine whether the cartilage microbial DNA pattern originates from the gut microbiome. To do this, we will populate the gut microbiome of germ-free mice with microbiota from young and OA-susceptible C57BL6/J (B6) mice then determine cartilage microbial DNA patterns at prespecified timepoints following inoculation. If successful, we will go on to test how variations in the cecal microbiome, associated with OA risk factors including aging and obesity, are reflected in changes of the cartilage microbiome profile. Furthermore, we will determine whether already-established cartilage microbiome patterns can be altered via changing the gut microbiome. Our second Aim will determine whether cartilage microbial DNA is sufficient to change the risk for OA development in mice. To do this, we will inject microbial DNA amplified from human OA patients and healthy controls into the knee joints of germ-free mice, then induce OA by disruption of the medial meniscus (DMM) surgery and measure histopathological outcome. If successful, we will then go on to determine local and systemic inflammatory cell population changes by CyTOF, serum cytokine changes by Bioplex assay, and epigenetic and transcriptomic changes on a genome-wide level following intraarticular microbial DNA delivery. The proposed work is important, as we do not have a full understanding of how non-genetic OA risk factors increases OA risk, nor do we understand how the microbiome influences OA risk. Our work is quite innovative in its use of germ-free mouse microbiome transplantation to evaluate OA and the use of cutting-edge CyTOF and epigenetic analyses. Finally, we will be the first to evaluate whether gut microbiome transplantation may be used as a therapeutic agent to prevent OA. Success in our proposal may open a new avenue for OA aging research and may offer a novel treatment strategy for OA.