This study aims to investigate the impact of hepatocyte nuclear factor 1β (HNF1b) on macrophage sortilin-mediated lipid metabolism and aortic atherosclerosis and explore the role of the flavone of Polygonatum odoratum (PAOA-flavone)-promoted small ubiquitin-related modifier (SUMO) modification in the atheroprotective efficacy of HNF1b. HNF1b was predicted to be a transcriptional regulator of sortilin expression via bioinformatics, dual-luciferase reporter gene assay, and chromatin immunoprecipitation. HNF1b overexpression decreased sortilin expression and cellular lipid contents in THP-1 macrophages, leading to a depression in atherosclerotic plaque formation in low-density lipoprotein (LDL) receptor-deficient (LDLR-/-) mice. Multiple SUMO1-modified sites were identified on the HNF1b protein and co-immunoprecipitation confirmed its SUMO1 modification. The SUMOylation of HNF1b protein enhanced the HNF1b-inhibited effect on sortilin expression and reduced lipid contents in macrophages. PAOA-flavone treatment promoted SUMO-activating enzyme subunit 1 (SAE1) expression and SAE1-catalyzed SUMOylation of the HNF1b protein, which prevented sortilin-mediated lipid accumulation in macrophages and the formation of atherosclerotic plaques in apolipoprotein E-deficient (ApoE-/-) mice. Interference with SAE1 abrogated the improvement in lipid metabolism in macrophage cells and atheroprotective efficacy in vivo upon PAOA-flavone administration. In summary, HNF1b transcriptionally suppressed sortilin expression and macrophage lipid accumulation to inhibit aortic lipid deposition and the development of atherosclerosis. This anti-atherosclerotic effect was enhanced by PAOA-flavone-facilitated, SAE1-catalyzed SUMOylation of the HNF1b protein.
本研究旨在探究肝细胞核因子1β（HNF1b）对巨噬细胞分拣蛋白（sortilin）介导的脂质代谢和主动脉粥样硬化的影响，以及玉竹（Polygonatum odoratum）黄酮在促进HNF1b的小泛素蛋白（SUMO）化修饰在动脉粥样硬化保护功效中的作用。通过生物信息学、双荧光素酶报告基因分析和染色质免疫共沉淀试验预测了HNF1b是sortilin表达的转录调控因子。HNF1b过表达降低了人髓系白血病单核（THP-1）巨噬细胞中sortilin的表达和细胞内脂质含量，从而抑制了LDLR–/–小鼠的动脉粥样斑块形成。在HNF1b蛋白上鉴定出多个SUMO1修饰位点，并通过免疫共沉淀证实存在SUMO1修饰。HNF1b蛋白的SUMO化修饰增强了HNF1b对sortilin表达的抑制作用，并降低了巨噬细胞中的脂质含量。玉竹黄酮处理促进了SUMO活化酶E1（SAE1）的表达和SAE1催化下对HNF1b蛋白的SUMO化修饰，从而阻止了巨噬细胞中sortilin介导的脂质积累和ApoE–/–小鼠的动脉粥样斑块形成，而对SAE1的干扰使得巨噬细胞内脂质代谢的改善和玉竹黄酮治疗对体内抗动脉粥样硬化效果消失。因此，HNF1b通过转录抑制sortilin表达和巨噬细胞内脂质积累，抑制主动脉脂质沉积和动脉粥样硬化的发展，玉竹黄酮促进SAE1催化的HNF1b蛋白SUMO化修饰增强了其抗动脉粥样硬化效应。.
本研究旨在探究肝细胞核因子1β（HNF1b）对巨噬细胞分拣蛋白（sortilin）介导的脂质代谢和主动脉粥样硬化的影响，以及玉竹（Polygonatum odoratum）黄酮在促进HNF1b的小泛素蛋白（SUMO）化修饰在动脉粥样硬化保护功效中的作用。通过生物信息学、双荧光素酶报告基因分析和染色质免疫共沉淀试验预测了HNF1b是sortilin表达的转录调控因子。HNF1b过表达降低了人髓系白血病单核（THP-1）巨噬细胞中sortilin的表达和细胞内脂质含量，从而抑制了LDLR–/–小鼠的动脉粥样斑块形成。在HNF1b蛋白上鉴定出多个SUMO1修饰位点，并通过免疫共沉淀证实存在SUMO1修饰。HNF1b蛋白的SUMO化修饰增强了HNF1b对sortilin表达的抑制作用，并降低了巨噬细胞中的脂质含量。玉竹黄酮处理促进了SUMO活化酶E1（SAE1）的表达和SAE1催化下对HNF1b蛋白的SUMO化修饰，从而阻止了巨噬细胞中sortilin介导的脂质积累和ApoE–/–小鼠的动脉粥样斑块形成，而对SAE1的干扰使得巨噬细胞内脂质代谢的改善和玉竹黄酮治疗对体内抗动脉粥样硬化效果消失。因此，HNF1b通过转录抑制sortilin表达和巨噬细胞内脂质积累，抑制主动脉脂质沉积和动脉粥样硬化的发展，玉竹黄酮促进SAE1催化的HNF1b蛋白SUMO化修饰增强了其抗动脉粥样硬化效应。
Keywords: Atherosclerosis; Flavone of Polygonatum odoratum; Hepatocyte nuclear factor 1β (HNF1b); Lipid accumulation; SUMOylation.