National Key Laboratory for Innovation and Transformation of Luobing Theory; The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences; Department of Cardiology, Qilu Hospital of Shandong University, Jinan, China (C.M., Y.L., Q.D., X.Q., H.L., M.Z., P.B., J.Y., Y.Z., C.Z., W.Z.).
Department of Critical Care Medicine, Qilu Hospital, Cheeloo College of Medicine (Y.L.), Shandong University, Jinan, China.
Circ Res. 2024 Mar 29;134(7):e34-e51. doi: 10.1161/CIRCRESAHA.123.323156. Epub 2024 Feb 20.
Many cardiovascular pathologies are induced by signaling through G-protein-coupled receptors via Gsα (G protein stimulatory α subunit) proteins. However, the specific cellular mechanisms that are driven by Gsα and contribute to the development of atherosclerosis remain unclear.
High-throughput screening involving data from single-cell and bulk sequencing were used to explore the expression of Gsα in atherosclerosis. The differentially expression and activity of Gsα were analyzed by immunofluorescence and cAMP measurements. Macrophage-specific Gsα knockout (Mac-Gsα) mice were generated to study the effect on atherosclerosis. The role of Gsα was determined by transplanting bone marrow and performing assays for foam cell formation, Dil-ox-LDL (oxidized low-density lipoprotein) uptake, chromatin immunoprecipitation, and luciferase reporter assays.
ScRNA-seq showed elevated in atherosclerotic mouse aorta's cholesterol metabolism macrophage cluster, while bulk sequencing confirmed increased expression in human plaque macrophage content. A significant upregulation of Gsα and active Gsα occurred in macrophages from human and mouse plaques. Ox-LDL could translocate Gsα from macrophage lipid rafts in short-term and promote transcription through ERK1/2 activation and C/EBPβ phosphorylation via oxidative stress in long-term. Atherosclerotic lesions from Mac-Gsα mice displayed decreased lipid deposition compared with those from control mice. Additionally, Gsα deficiency alleviated lipid uptake and foam cell formation. Mechanistically, Gsα increased the levels of cAMP and transcriptional activity of the cAMP response element binding protein, which resulted in increased expression of CD36 and SR-A1. In the translational experiments, inhibiting Gsα activation with suramin or cpGN13 reduced lipid uptake, foam cell formation, and the progression of atherosclerotic plaques in mice in vivo.
Gsα activation is enhanced during atherosclerotic progression and increases lipid uptake and foam cell formation. The genetic or chemical inactivation of Gsα inhibit the development of atherosclerosis in mice, suggesting that drugs targeting Gsα may be useful in the treatment of atherosclerosis.
许多心血管病理学是通过 G 蛋白偶联受体（GPCR）信号转导，经由 Gsα（G 蛋白刺激α亚基）蛋白诱导的。然而，由 Gsα 驱动并导致动脉粥样硬化发展的确切细胞机制仍不清楚。
利用单细胞和批量测序的数据进行高通量筛选，以探索 Gsα 在动脉粥样硬化中的表达情况。通过免疫荧光和 cAMP 测量分析 Gsα 的差异表达和活性。生成巨噬细胞特异性 Gsα 敲除（Mac-Gsα）小鼠，以研究其对动脉粥样硬化的影响。通过移植骨髓并进行泡沫细胞形成、Dil-ox-LDL（氧化低密度脂蛋白）摄取、染色质免疫沉淀和荧光素酶报告基因检测来确定 Gsα 的作用。
scRNA-seq 显示，在动脉粥样硬化小鼠主动脉胆固醇代谢巨噬细胞簇中上调，而批量测序则证实人类斑块巨噬细胞含量中上调。在人类和小鼠斑块中的巨噬细胞中，Gsα 和活性 Gsα 的表达显著上调。Ox-LDL 可在短期内将 Gsα 从巨噬细胞脂筏中转位，并通过氧化应激激活 ERK1/2 和磷酸化 C/EBPβ，长期促进转录。与对照小鼠相比，Mac-Gsα 小鼠的动脉粥样硬化病变显示脂质沉积减少。此外，Gsα 缺乏可减轻脂质摄取和泡沫细胞形成。在机制上，Gsα 增加了 cAMP 的水平和 cAMP 反应元件结合蛋白的转录活性，从而增加了 CD36 和 SR-A1 的表达。在翻译实验中，用苏拉明或 cpGN13 抑制 Gsα 激活可减少脂质摄取、泡沫细胞形成和体内小鼠动脉粥样硬化斑块的进展。
在动脉粥样硬化进展过程中，Gsα 的激活增强，增加了脂质摄取和泡沫细胞形成。Gsα 的遗传或化学失活可抑制小鼠动脉粥样硬化的发展，表明靶向 Gsα 的药物可能对动脉粥样硬化的治疗有用。
