基于单细胞转录组测序技术的食品中甾醇氧化物促细胞泡沫化作用及其机制研究

细胞泡沫化是动脉粥样硬化早期发生、发展的重要病理基础。前期研究发现食品贮藏加工中产生的甾醇氧化物具有致动脉粥样硬化的潜在危害，但是其吸收转运以及促细胞泡沫化的机制亟待研究。本项目拟以7-酮基胆固醇、7-酮基谷甾醇等食品中主要甾醇氧化物为对象，利用Caco-2/HT29-MTX细胞吸收模型、ApoE基因缺陷小鼠动脉粥样硬化模型、THP-1源巨噬细胞模型，整合单细胞转录组测序、靶向脂质代谢组学等手段，解析食品中甾醇氧化物的吸收转运、体内分布及其代谢规律，探析其对动脉粥样硬化早期斑块形成以及细胞泡沫化、炎症反应、脂质代谢的影响，锚定泡沫化的靶标细胞亚型及其分型规律；从胆固醇的摄入、酯化及流出等方面探明甾醇氧化物致脂质代谢异常的机制，从NLRP3炎症小体等方面探明其致炎症调控失衡的机制，从JAK/STAT等通路探明其致细胞极化分型的机制，从而揭示食品中甾醇氧化物促巨噬细胞泡沫化作用机制。

Foam cell formation is the main pathology of early atherosclerosis. Previous studies have found that oxysterols produced by food thermal processing, such as 7-keto-cholesterol can cause the formation of foam cells, which potentially accelerates atherosclerosis. However, the absorption of foodborne oxysterols in vivo and the mechanism of oxysterols aggravating foam cell formation still need further investigation. Thus, major oxysterols in diets such as 7-keto-cholesterol and 7-keto-sitosterol were researched in this study. Based on Caco-2/HT29-MTX cell model and ApoE deficient mice model, the absorption mechanism, distribution and metabolism of food-borne oxysterols are analyzed, using single-cell sequencing and target lipid metabolomics. The effects of oxysterols on plaque formation in the early stage of atherosclerosis, foam cell formation, inflammatory response, and lipid metabolism are investigated, the target subtypes of foam cell formation and their polarization are analyzed by heterogeneity analysis. Macrophage model derived from THP-1 cells is used to explore the mechanism of oxysterols on regulating imbalanced inflammatory response by activating NLRP3 inflammasome and NF-κB signaling pathway, on promoting macrophage foaming from the aspects of oxidized low-density lipoprotein intake, cholesterol esterification and efflux, and on cell polarization and phenotyping induced by oxysterols via multiple signaling pathways, such as JAK/STAT, PI3K/Akt, and JNK pathway. The multiple mechanisms of food-borne oxysterols promoting foam cell formation are revealed based on the above three aspects.