Intraarticular microbial DNA as a novel mediator of osteoarthritis

项目摘要/摘要 这项拟议的研究的目的是更好地了解软骨微生物DNA模式是如何 以及这些因素与骨关节炎(OA)的发病机制和进展的关系。以前发布的版本 研究已经概述了肠道微生物群随年龄增长的促炎变化，但还没有工作。 用来检查肠道和/或软骨微生物群、炎症和表观遗传学是如何相交的 和OA在一起。我们的实验室之前已经详细地检查了软骨内的表观遗传学变化和 软骨下骨与骨性关节炎的发展有关，我们最近检查了表观遗传学的变化 在人类骨性关节炎患者的外周血细胞中，与快速骨性关节炎风险增加相关 进步。我们的第一个目标是确定软骨微生物DNA模式是否起源于 肠道微生物群。为了做到这一点，我们将用幼鼠的微生物群填充无菌小鼠的肠道微生物群。 和OA易感的C57BL6/J(B6)小鼠，然后在预先指定的条件下测定软骨微生物DNA图谱 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异， 与骨性关节炎相关的危险因素，包括衰老和肥胖，反映在软骨微生物群的变化上 侧写。此外，我们将确定已经建立的软骨微生物组模式是否可以 通过改变肠道微生物群而改变。我们的第二个目标将确定软骨微生物DNA是否 足以改变小鼠发生骨性关节炎的风险。为了做到这一点，我们将把从 人骨关节炎患者和健康对照组进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 通过细胞免疫荧光检测局部和全身炎症细胞群的变化，血清细胞因子的变化 BioPlex分析以及关节内后全基因组水平上的表观遗传学和转录学变化 微生物DNA传递。拟议的工作很重要，因为我们还不完全了解如何 非遗传性骨性关节炎风险因素会增加骨性关节炎的风险，我们也不了解微生物群是如何影响骨性关节炎风险的。 我们的工作在使用无菌小鼠微生物组移植来评估OA和 使用尖端细胞飞行时间和表观遗传学分析。最后，我们将第一个评估Gut 微生物组移植可作为预防骨性关节炎的治疗药物。我们的提议可能会取得成功 为骨性关节炎的衰老研究提供了新的途径，并可能为骨性关节炎的治疗提供新的策略。

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.