Porphyromonas gingivalis glycine lipids mediate bone loss through TLR2

牙龈卟啉单胞菌是一种牙周病原体，与牙周炎的发生和发展有关。 成人慢性牙周炎。我们最近证明了这种有机体产生了两种新的 丝氨酸脂类抑制骨细胞功能并激活巨噬细胞释放重要的 细胞因子。这些丝氨酸脂中至少有一种还介导其对小鼠骨细胞和 巨噬细胞通过参与先天免疫系统，特别是通过Toll受体2 (TLR2)。我们最近还在牙龈假单胞菌中发现了一类新的甘氨酸脂 启动TLR2。名为Lipid 342的甘氨酸类与TLR2结合但仅包含一个酰基链， 这表明它是迄今所描述的最小的TLR2激动剂。了解甘氨酸脂是如何促进 依赖TLR2的细胞效应与已报道的牙龈假单胞菌对人牙周炎的影响有关 实验动物的牙周骨丢失。牙龈假单胞菌甘氨酸脂的不同寻常之处在于它们可以 与小鼠骨髓巨噬细胞原代培养时，由丝氨酸脂产生 当用磷脂酶处理时，可以从另一种甘氨酸脂，脂类567中产生脂类342 A2(PLA2)。值得注意的是，慢性炎症与PLA2表达增加有关，PLA2 导致慢性炎症组织内前列腺素水平升高。此应用程序建议 定量测定人牙龈细胞对丝氨酸和甘氨酸脂的摄取和水解量，包括 上皮细胞、成纤维细胞和巨噬细胞。接下来，我们将评估这些脂质类的能力 在原代培养的人牙龈细胞中接触TLR2及其辅助受体。最后，我们会 评估这些脂类促进人巨噬细胞形成破骨细胞的能力。 M-CSF诱导人巨噬细胞与外周血单核细胞分化的研究 而破骨细胞的形成将在用丝氨酸脂类甘氨酸处理后进行评估。我们 还将用不同类别的甘氨酸和丝氨酸脂治疗M-CSF分化的巨噬细胞 并评价巨噬细胞培养上清促进破骨细胞形成的能力。这个 本提案中总结的实验将阐明牙龈假单胞菌是如何促进依赖TLR2的骨骼的。 在牙周病中的损失。

Porphyromonas gingivalis is a periodontal pathogen implicated in the initiation and progression of chronic periodontitis in adults. We recently demonstrated that this organism produces two novel classes of serine lipids that inhibit bone cell function and activate macrophages to release important cytokines. At least one of these serine lipids also mediates its effects on mouse bone cells and macrophages through engagement of the innate immune system, specifically through Toll Receptor 2 (TLR2). We also have recently discovered a new class of glycine lipids in P. gingivalis that also engage TLR2. The glycine class called Lipid 342 engages TLR2 but contains only one acyl chain, indicating that it is the smallest TLR2 agonist yet described. Understanding how glycine lipids promote TLR2-dependent cellular effects is relevant specifically to the reported effects of P. gingivalis on periodontal bone loss in experimental animals. P. gingivalis glycine lipids are unusual in that they can be produced from serine lipids when exposed to primary cultures of mouse bone marrow macrophages and Lipid 342 can be produced from another glycine lipid, Lipid 567, when treated with phospholipase A2 (PLA2). Of note, chronic inflammation is associated with increased expression of PLA2 which results in elevated prostaglandin levels within chronically inflamed tissues. This application proposes to quantify the uptake and hydrolysis of serine and glycine lipids in human gingival cells including epithelial, fibrobast and macrophages. Next, we will evaluate the capacity of these lipid classes to engage TLR2 and its co-receptor in primary cultures of the human gingival cells. Finally, we will evaluate the capacity of these lipid classes to promote osteoclast formation from human macrophages. Human macrophages will be differentiated from peripheral blood monocytes by treatment with M-CSF and osteoclast formation will be evaluated after treatment with the glycine of serine lipid classes. We will also treat M-CSF differentiated macrophages with the various classes of glycine and serine lipids and evaluate the capacity of macrophage culture supernatants to promote osteoclast formation. The experiments summarized in this proposal will clarify how P. gingivalis promotes TLR2-dependent bone loss in periodontal diseases.