Targeting Succinate Signaling Impedes Periodontitis Progression

摘要 2型糖尿病被认为是严重和进展性糖尿病的重要危险因素 牙周炎。糖尿病可能通过代谢失调加速牙周炎， 细菌定植、炎症和骨质丢失的转移。我们最近发现琥珀酸 激活琥珀酸受体(SucnR1)，刺激破骨细胞生成和骨吸收。我们的 初步数据进一步显示：(1)龈沟液(GCF)中琥珀酸含量升高 牙周炎患者的牙槽骨高度显著高于牙周炎患者。 牙周炎与T2D；(2)T2D小鼠自发性牙周炎伴有牙周炎升高 牙周组织中琥珀酸水平和胃肠道微生物群改变与正常的比较 小鼠；(3)琥珀酸在体外有利于牙周病原体的生长；(4)外源琥珀酸 增加野生型(WT)的牙周骨丢失；(5)牙周骨丢失 在SucnR1基因敲除小鼠(KO)中得到缓解。目前的提议建立在强有力的基础上 确定琥珀酸升高是否会加速牙周病的初步数据 进步。我们将使用老鼠模型来测试我们的假设，即以琥珀酸为靶点 信号传递可防止牙周病发病加速。在目标1中，我们将使用喂食的小鼠 在正常饮食中，喂食高脂饮食(HFD)的小鼠会变得高血糖，并形成琥珀酸 受体敲除小鼠(SucnR1_KO)确定琥珀酸/SucnR1信号转导 影响正常血糖和高血糖患者的全身反应和改变口腔微生物区系 条件。我们将使用细菌从牙周部位转移到无菌小鼠身上来测试 致病性通过细菌引起的骨丢失来衡量。我们的工作假设是细菌 来自HFD糖尿病小鼠的比来自匹配的正常血糖的细菌会导致更多的骨丢失 控制。在目标2中，我们将确定琥珀酸是否激活SucnR1以增强牙周 炎症刺激引起的骨丢失。在目标3中，我们将确定阻止 破骨前细胞中的琥珀酸信号可减轻牙周组织的骨丢失。我们将使用lysMCre， SucnR1L/L小鼠模型评估琥珀酸信号是否通过其受体增强 非炎性刺激导致骨丢失。我们还将测试特定SucnR1的有效性 拮抗剂在T2D小鼠自发发展模型中预防牙周炎的作用 牙周炎。我们认为，通过激活SucnR1，琥珀酸具有重要意义 通过描绘这一新的机制，我们将有助于预防 糖尿病患者的牙周骨丢失。

Abstract Type 2 Diabetes is recognized as an important risk factor for more severe and progressive periodontitis. Diabetic condition may accelerate periodontitis through metabolic dysregulation, shift in bacterial colonization, inflammation, and bone loss. We recently found that succinate activates succinate receptor (SucnR1) to stimulate osteoclastogenesis and bone resorption. Our preliminary data further show (1) succinate was elevated in the gingival crevicular fluid (GCF) from periodontitis patients and the elevation was significantly greater in patients with both periodontitis and T2D; (2) spontaneous periodontitis in T2D mice was accompanied by elevated succinate levels in the periodontium and altered gastrointestinal microbiome compare to normal mice; (3) succinate favors the growth of periodontal pathogens in vitro; (4) exogenous succinate enhances periodontal bone loss in wild type (WT); and (5) the periodontal bone loss is mitigated in SucnR1 knock out mice (KO) mice. The current proposal is built on strong preliminary data to determine whether succinate elevation accelerates periodontal disease progression. We will employ mouse models to test our hypotheses that targeting succinate signaling prevents accelerated periodontal disease pathogenesis. In Aim 1 we will use mice fed on normal diet, mice fed on High Fat Diet (HFD) which become hyperglycemic, and succinate receptor knock out mice (SucnR1_KO) to determine whether succinate/SucnR1 signaling influences systemic response and alters oral microbiota in normal and hyperglycemia conditions. We will use bacterial transfer from the periodontal site to germ free mice to test the pathogenicity as measured by bacteria-induced bone loss. Our working hypothesis is bacteria from HFD diabetic mice will induce more bone loss than bacteria from matched normoglycemic controls. In Aim 2 we will determine whether succinate activates SucnR1 to enhance periodontal bone loss stimulated by inflammation stimulus. In Aim 3 we will determine whether blocking succinate signaling in pre-osteoclasts alleviates periodontium bone loss. We will use lysMCre, SucnR1L/L mouse model to assess whether succinate signaling through its receptor to enhance non-inflammatory stimuli induced bone loss. We will also test the efficacy of a specific SucnR1 antagonist in preventing periodontitis in a T2D mouse model that spontaneously develop periodontitis. We propose that via activation of SucnR1, succinate has significant implications in periodontal disease and by delineating this novel mechanism, we will help to prevent periodontal bone loss in diabetic patients.