细胞胞吞功能障碍是动脉粥样硬化斑块进展和破裂的原因之一。细胞胞吞关键受到胞浆内Ca2+的调节，线粒体钙离子载体（MCU）复合物蛋白是调控Ca2+浓度的关键通道。因此，我们推测MCU可能通过调节细胞胞吞来影响动脉粥样硬化（AS）的发展。本研究旨在调查MCU是否能通过调节细胞胞吞来影响泡沫细胞形成。我们使用氧化低密度脂蛋白（ox-LDL）刺激原代巨噬细胞（Møs）以模拟动脉粥样硬化微环境，并用Ru360（一种MCU特异性抑制剂）和UNC062（一种细胞胞吞抑制剂）进行处理。此外，我们进行了双染色以确定Mø细胞胞吞率。我们分别通过Western blotting（WB）和实时定量聚合酶链反应（RT-qPCR）来测量MCU复合物和细胞胞吞相关蛋白的表达。此外，我们使用Fluo-4 AM和Rhod-2方法分别检测胞浆和线粒体（MT）中的Ca2+水平。我们还使用二氯二羥荧光素乙酸酯（DCFH-DA）荧光探测法和Mito-SOX超氧阴离子指示剂染色法分别测定胞浆和MT中的活性氧（ROS）水平。此外，我们进行了酶联免疫吸附实验（ELISA）以检测白介素-6（IL-6）、白介素-18（IL-18）、白介素-1β（IL-1β）和肿瘤坏死因子-α（TNF-α）的产生。我们还进行红油O染色以测量胞质中的脂质水平。Ru360减轻了ox-LDL诱导的细胞胞吞功能障碍，减轻了ox- LDL诱导的MCU和MCUR1上调，并减轻了ox-LDL诱导的MCUb下调。Ru360减轻了ox-LDL诱导的胞浆Ca2+浓度下降，同时减轻了ox-LDL诱导的ROS生成，减轻了ox-LDL诱导的IL-6、IL-18、IL-1β和TNF-α释放，并减轻了ox-LDL诱导的胞浆脂质含量增加。UNC1062减轻了Ru360减少炎症因子和胞浆脂质含量的作用。在本研究中，我们发现MCU抑制能够调节胞浆Ca2+浓度，改善受损的Mø细胞胞吞，减少ROS的产生。巨噬细胞细胞胞吞去除凋亡细胞，阻止炎症因子的释放和泡沫细胞的形成，这可能是缓解动脉粥样硬化的潜在新治疗靶点。版权所有 © 2023 Elsevier B.V. 发布。

Efferocytosis dysfunction contributes to the progression and rupture of atherosclerotic plaques. Efferocytosis is crucially modulated by intracytoplasmic Ca2+, and mitochondrial calcium uniporter (MCU) complex proteins serve as key channels for regulating Ca2+ concentration. Therefore, it was speculated that MCU may affect the development of atherosclerosis (AS) by regulating efferocytosis. In the present study, we aimed to investigate whether MCU could affect foam cell formation by regulating efferocytosis.We stimulated primary macrophages (Møs) using oxidized low-density lipoprotein (ox-LDL) to mimic the atherosclerotic microenvironment and treated them with Ru360, an MCU-specific inhibitor, and UNC1062, an inhibitor of efferocytosis. Additionally, we conducted double staining to determine the Mø efferocytosis rate. We measured the expression of MCU complexes and efferocytosis-associated proteins using western blotting (WB) and real-time quantitative polymerase chain reaction (RT-qPCR), respectively. In addition, we separately detected the Ca2+ level in the cytoplasm and mitochondria (MT) using Fluo-4 AM and Rhod-2 methods. We separately determined the reactive oxygen species (ROS) level in cytoplasm and MT using dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probing method and Mito-SOXTM superoxide indicator staining. Additionally, we conducted the enzyme-linked immunosorbent assay (ELISA) to detect the production of interleukin-6 (IL-6), interleukin-18 (IL-18), interleukin-1β (IL-1β), and tumor necrosis factor-alpha (TNF-α). Oil Red O staining was performed to measure cytoplasmic lipid levels.Ru360 attenuated ox-LDL-induced efferocytosis dysfunction, and attenuated the upregulation of MCU and MCUR1 induced by ox-LDL, and meanwhile attenuated the downregulation of MCUb induced by ox-LDL. Ru360 attenuated the decrease of intracytoplasmic Ca2+ concentration induced by ox- LDL, Ru360 also attenuated the ROS production induced by ox- LDL, attenuated the release of IL-6, IL-18, IL-1β, and TNF-α induced by ox- LDL, and attenuated the increase of intracytoplasmic lipid content induced by ox-LDL. UNC1062 attenuated the effects of Ru360 in reducing inflammatory cytokines and intracytoplasmic lipid content.In this study, we found that MCU inhibition modulated intracytoplasmic Ca2+ concentration, improved impaired Mø efferocytosis, and reduced ROS generation. Macrophage efferocytosis removed apoptotic cells and prevented the release of inflammatory factor and foam cell formation, and this can be a potential new therapeutic target for alleviating atherosclerosis.Copyright © 2023. Published by Elsevier B.V.