牙龈卟啉单胞菌感染对单核细胞源性泡沫细胞形成的影响及其机理

最新资料支持牙周炎是心血管疾病（CVD）的独立危险因素，两者相关联的生物学机制备受关注。近来血清流行病学、动物和细胞分子学研究发现:作为慢性牙周炎主要致病菌之一的牙龈卟啉单胞菌（P.g）可入血并侵入血管壁，参与动脉粥样硬化（AS）的发生发展。鉴于巨噬细胞形成泡沫细胞在AS发生发展中的关键性作用，申请人通过前期的探索性研究工作初步证实:P.g感染单核细胞源性巨噬细胞后可显著促进其形成泡沫细胞。但其机理尚不清楚，亦未见相关报道。本研究拟在前期已建立的P.g感染人单核细胞源性巨噬细胞体外模型的基础上，采用脂质染色和胆固醇测定法观察P.g感染单核细胞源性巨噬细胞后对泡沫细胞形成的影响；从基因和蛋白水平了解P.g感染后巨噬细胞胆固醇代谢关键分子的表达变化；探讨PPARs信号通路在P.g促进泡沫细胞形成中的作用，旨在阐明P.g感染在牙周炎与CVD相关性中的生物学机制，为CVD的早期干预提供实验依据。

Recent a growing body of evidences suggested that periodontitis is a independent risk factor for cardiovascular disease(CVD).To discover the biological mechanism between periodontal disease and CVD has been a new research area.In recent years seroepidemiology、animal and molecular biology studies have suggested that P.g,which is a major etiologic agent in the pathogenesis of periodontal disease in humans, can diffuse into bloodstream and invade into the arterial wall and human coronary endothelial cells, then upregulate the expression of cell adhension molecules in endothelial cells. These evidences suggested that P.g infection may be associated with the development of atherosclerosis. In light of the formation of macrophage foam cells in the arterial intima is a hallmark of early lesion formation in atherosclerosis and the imbalance of cholesterol metabolism home ostasis in macrophage contributes to foam cell formation,we have provided evidence to confirm that infection by P.g can induce foam cell formation by human monocyte-derived macrophages.And P.g may play a important role in formation of macrophage foam cells in cardiovascular tissue. However, detailed mechanisms have not fully been studied. In order to investigate potential role of P.g in the biological mechanism between periodontitis and CVD , the model of infection of monocyte-derived macrophages by P.g will be established in vitro in the present study:1)To observe the effect of P.g infection on the formation of THP-1-derived foam cells in vitro. Lipid droplets in cytoplasm were observed by oil red O staining.The Contents of intraeellula cholesterylesters were detected by enzymic chromatometry;2) To investigate the roles of the expressions of mRNA and protein of key genes involved in macrophage cholesterol metabolism in P.g-induced foam cell formation by PCR and Western blot;3) To discuss the pathways of P.g-induced foam cell formation.These research may provide new insights for the development and progression of atheroselerosis initiated by P. g infection and supply evidences for the intervention and treatment of CVD in the early stage.