BACKGROUND Cell phenotype switching is increasingly being recognized in atherosclerosis. However, our understanding of the exact stimuli for such cellular transformations and their significance for human atherosclerosis is still evolving. Intraplaque hemorrhage is thought to be a major contributor to plaque progression in part by stimulating the influx of CD163+ macrophages. Here, we explored the hypothesis that CD163+ macrophages cause plaque progression through the induction of proapoptotic endothelial-to-mesenchymal transition (EndMT) within the fibrous cap. METHODS Human coronary artery sections from CVPath's autopsy registry were selected for pathological analysis. Athero-prone ApoE-/- and ApoE-/-/CD163-/- mice were used for in vivo studies. Human peripheral blood mononuclear cell-induced macrophages and human aortic endothelial cells were used for in vitro experiments. RESULTS In 107 lesions with acute coronary plaque rupture, 55% had pathological evidence of intraplaque hemorrhage in nonculprit vessels/lesions. Thinner fibrous cap, greater CD163+ macrophage accumulation, and a larger number of CD31/FSP-1 (fibroblast specific protein-1) double-positive cells and TUNEL (terminal deoxynucleotidyl transferase-dUTP nick end labeling) positive cells in the fibrous cap were observed in nonculprit intraplaque hemorrhage lesions, as well as in culprit rupture sections versus nonculprit fibroatheroma sections. Human aortic endothelial cells cultured with supernatants from hemoglobin/haptoglobin-exposed macrophages showed that increased mesenchymal marker proteins (transgelin and FSP-1) while endothelial markers (VE-cadherin and CD31) were reduced, suggesting EndMT induction. Activation of NF-κB (nuclear factor kappa β) signaling by proinflammatory cytokines released from CD163+ macrophages directly regulated the expression of Snail, a critical transcription factor during EndMT induction. Western blot analysis for cleaved caspase-3 and microarray analysis of human aortic endothelial cells indicated that apoptosis was stimulated during CD163+ macrophage-induced EndMT. Additionally, CD163 deletion in athero-prone mice suggested that CD163 is required for EndMT and plaque progression. Using single-cell RNA sequencing from human carotid endarterectomy lesions, a population of EndMT was detected, which demonstrated significant upregulation of apoptosis-related genes. CONCLUSIONS CD163+ macrophages provoke EndMT, which may promote plaque progression through fibrous cap thinning.

中文翻译：

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CD163+巨噬细胞诱导动脉粥样硬化中的内皮细胞向间质细胞的转变。


背景细胞表型转换在动脉粥样硬化中越来越被认识到。然而，我们对这种细胞转化的确切刺激及其对人类动脉粥样硬化的重要性的理解仍在不断发展。斑块内出血被认为是斑块进展的主要原因，部分原因是刺激 CD163+ 巨噬细胞的流入。在这里，我们探讨了这样的假设：CD163+巨噬细胞通过诱导纤维帽内的促凋亡内皮-间质转化 (EndMT) 导致斑块进展。方法 选择来自 CVPath 尸检登记处的人类冠状动脉切片进行病理分析。易患动脉粥样硬化的 ApoE-/- 和 ApoE-/-/CD163-/- 小鼠用于体内研究。使用人外周血单核细胞诱导的巨噬细胞和人主动脉内皮细胞进行体外实验。结果 在 107 个急性冠状动脉斑块破裂病变中，55% 有非肇事血管/病变斑块内出血的病理证据。纤维帽变薄，CD163+巨噬细胞聚集增多，纤维帽中CD31/FSP-1（成纤维细胞特异性蛋白-1）双阳性细胞和TUNEL（末端脱氧核苷酸转移酶-dUTP缺口末端标记）阳性细胞数量增多在非罪魁祸首斑块内出血病变中，以及在罪魁祸首破裂切片与非罪魁祸首纤维粥样硬化切片中。用暴露于血红蛋白/触珠蛋白的巨噬细胞的上清液培养的人主动脉内皮细胞显示间充质标记蛋白（转胶蛋白和FSP-1）增加，而内皮标记物（VE-钙粘蛋白和CD31）减少，表明EndMT诱导。 CD163+巨噬细胞释放的促炎细胞因子激活 NF-κB（核因子 kappa β）信号，直接调节 Snail 的表达，Snail 是 EndMT 诱导过程中的关键转录因子。裂解的 caspase-3 的蛋白质印迹分析和人主动脉内皮细胞的微阵列分析表明，CD163+巨噬细胞诱导的 EndMT 过程中刺激了细胞凋亡。此外，易患动脉粥样硬化的小鼠中 CD163 缺失表明 CD163 是 EndMT 和斑块进展所必需的。使用人颈动脉内膜切除术病变的单细胞 RNA 测序，检测到 EndMT 群体，这表明细胞凋亡相关基因显着上调。结论 CD163+巨噬细胞引发 EndMT，这可能通过纤维帽变薄促进斑块进展。