武汉云克隆科技股份有限公司

Abstract: Membrane cholesterol modulates a variety of cell signaling pathways and functions. While cholesterol depletion by high-density lipoproteins (HDLs) has potent anti-inflammatory effects in various cell types, its effects on inflammatory responses in macrophages remain elusive. Here we show overt pro-inflammatory effects of HDL-mediated passive cholesterol depletion and lipid raft disruption in murine and human primary macrophages in vitro. These pro-inflammatory effects were confirmed in vivo in peritoneal macrophages from apoA-I transgenic mice, which have elevated HDL levels. In line with these findings, the innate immune responses required for clearance of P. aeruginosa bacterial infection in lung were compromised in mice with low HDL levels. Expression analysis, ChIP-PCR, and combinatorial pharmacological and genetic intervention studies unveiled that both native and reconstituted HDL enhance Toll-like-receptor-induced signaling by activating a PKC-NF-κB/STAT1-IRF1 axis, leading to increased inflammatory cytokine expression. HDL's pro-inflammatory activity supports proper functioning of macrophage immune responses.

摘要：膜胆固醇调节了各种细胞信号通路和功能。虽然高密度脂蛋白（HDLs）对胆固醇的消耗在各种细胞类型中具有强大的抗炎作用，但它对巨噬细胞炎症反应的影响仍然难以捉摸。在这里，我们展示了在体外培养的小鼠和人原代巨噬细胞中，HDL介导的被动胆固醇消耗和脂质筏破坏的明显促炎症作用。这些促炎症作用在apoA-I转基因小鼠体内得到的腹膜巨噬细胞中得到证实，这些细胞的HDL水平升高了。与这些发现一致的是，在低HDL水平的小鼠体内，肺中对清除铜绿假单胞菌感染所需的先天免疫应答被破坏。表达分析、ChIP-PCR和药理学及基因干扰的结合研究表明，天然的和重组的HDL都可通过激活PKC-NF-κB/STAT1-IRF1来增强Toll样受体诱导的信号传导，从而增加了炎症细胞因子的表达。HDL的促炎症活性支撑了巨噬细胞免疫应答的正常功能。

使用试剂原文信息：IL-12 (p40), TNF-a, CCL2, IFNb (Invitrogen), IL-10 (eBioscience), and apoA-I (Mabtech and USCN Life Science) ELISA was performed on conditioned medium according to the manufacturer’s instructions.