Intraarticular microbial DNA as a novel mediator of osteoarthritis

项目概要/摘要 这项研究的目的是为了更好地了解软骨微生物DNA模式是如何 建立，以及这些如何与骨关节炎（OA）的发病机制和进展。此前公布 研究已经概述了肠道微生物组促炎性变化与衰老，但还没有工作 已经进行了检查肠道和/或软骨微生物组，炎症和表观遗传学如何交叉 关于OA我们的实验室先前已经详细检查了软骨内的表观遗传变化， 软骨下骨与OA的发展有关，我们最近研究了表观遗传变化 在人类OA患者的外周血细胞中，其与快速OA的风险增加相关 进展我们的第一个目标是确定软骨微生物DNA模式是否来源于 肠道微生物组为了做到这一点，我们将在无菌小鼠的肠道微生物组中植入来自年轻小鼠的微生物群。 和OA易感的C57 BL 6/J（B6）小鼠，然后在预先指定的温度下测定软骨微生物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组的变化， 与包括衰老和肥胖在内的OA风险因素相关的，反映在软骨微生物组的变化中 profile.此外，我们将确定是否已经建立的软骨微生物组模式可以 通过改变肠道微生物组来改变。我们的第二个目标是确定软骨微生物DNA是否 足以改变小鼠中OA发展的风险。为了做到这一点，我们将注入微生物DNA扩增， 将人类OA患者和健康对照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测定局部和全身炎症细胞群的变化，通过CyTOF测定血清细胞因子的变化， Bioplex测定，以及关节内注射后全基因组水平上的表观遗传学和转录组学变化 微生物DNA递送。拟议的工作很重要，因为我们还没有充分了解如何 非遗传性OA风险因素增加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 使用最先进的细胞飞行时间和表观遗传学分析。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。如果我们的提议成功 为OA衰老研究提供了新的途径，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.