我们发现人群血浆硒蛋白P(SelP)水平与动脉粥样硬化(AS)发生风险呈负相关，人SelP含有10个硒代半胱氨酸基序(UM)，对生物应激调控起重要作用，其对AS血管炎症应激和巨噬细胞(Mø)功能的调节作用与机制亟待阐明。本项目拟利用SelP和UM突变Mø、CoIP-质谱联用分析炎症信号诱导SelP/UM棕榈酰化和亚硝基化修饰；再利用APOE与SelP基因共敲、肝脏和Mø条件敲除及SelP敲入拯救等小鼠模型，阐明SelP/UM调节AS血管炎症和Mø胆固醇转运、泡沫化、胞葬清除和铁死亡的机制，揭示SelP对AS脂质炎症信号感应的翻译后修饰方式，发现SelP对AS血管炎症信号和Mø功能调控新机制，为应用SelP和UM多肽防治AS提供理论依据；还将实现SelP和UM硒肽高效重组表达，成功制备SelP/UM硒肽，创新SelP/UM硒肽富载的纳米硒在AS血管炎症Mø靶向递送，具有防治AS转化应用前景。

Selenium (Se), an essential micronutrient element for mammals, plays important roles in anti-oxidative stress and inflammation immunity primarily in forms of 25 selenoproteins in human beings. Selenoprotein P (SelP) is an extracellular, most abundant and monomeric glycoprotein containing up to 10 selenocysteine (U) residues. Recently, we performed a case-control survey to explore the correlation between plasma SelP and the atherogenic index of plasma (AIP) in a population of 330 participants recruited from Meizhou regions with various Se dietary status. Preliminary data reveals that plasma SelP concentrations are inverse associations with the AIP indicating SelP close related to atherosclerosis (AS) in population. Herein, we focus on the mechanism of SelP and its U containing motifs (UM) in regulating the inflammatory signaling and macrophage activity, and also address preliminary medical transformation of SelP and UM peptides to prevent atherogenesis..Macrophages (Mø) are most numerous among leukocytes in the lesion of atherosclerosis (AS) and play a central role in the pathogenesis of plaques, but the mechanistic links between many AS associated factors and Mø mediated reversible cholesterol (CE) transportion (RCT) in atherogenesis remain unclear. To discover the posttranslational modification (PTM) modes of palmitoylation (PALM) and S-nitrosylation (SNO) on the UMs of SelP in macrophages in response to the oxidized low density lipoprotein (oxLDL) induced inflammation signals, we constructed the over expression vectors of the wild type (WT) SelP and its mutants covering all of the 10 U residues, the adjacent cysteine (C) residues and the deletions or truncates of U containing motifs expression vector for SelP and its cysteine containing (U) motif. After transfection and expression in RAW 264.7 and 293T cells, target PTMs on SelP were detected by Western Blot Kits and identified by CoIP-MS/MS hyphenated technique. To investigate the role of SelP in AS, comparative studys of pathological atherogenesis will be conducted in the mouse models of AS, which are established in ApoE-/- mice coupled with mice of whole body SelP-/-, liver or Mø conditional depletion, and transgenetic SelP mice for rescue, respectively. To further elucidate the exact mechanism in regulating Mø characteristics of RCT, CE overloading, foam cell formation, efferocytosis and ferroptosis, which dynamically sensitized and orchestrated by PALM- or/and SNO-PTMs on UMs of SelP, cell models of primary Mø (BMDM), RAW264.7 or THP-1 cell lines with SelP gene edition will also be constructed..Additionally, novel recombination and high expression system of SelP and UM peptides will be setup by screening a effective selenocysteine insertion sequence (SECIS) to solve the pre-termination and inefficiency of UGA mediated selenoprotein translation. To further medical transformation of SelP/UM peptides, the invention and design of self-assembly protein (EPN) prefabricated nanocage with Se-nano core for SelP/UM peptides delivery is also proposed in the present project. With surface modification of the innovative nano particles loading SelP/UM peptides (SePNP) to target AS vascular macrophage, its therapeutic intervention to AS should be good in prospective application..Uncovering above roles and action mechanisms of SelP through selenocysteine motifs in response to inflammatory signaling and macrophage activity are critical for understanding how impairments in low Se status and SelP expression driven the atherogenesis, and the invention of SePNP will guide the medical transformation and application of selenoproteins in the treatment of AS related diseases.