Coronary artery disease (CAD) is a common cardiovascular disease, mainly due to vascular endothelial cell (VEC) injury caused by atherosclerosis. Circular RNA has been shown to be involved in the regulation of various diseases. However, the role and mechanism of circ_0004104 in CAD are still unclear. Oxidized low-density lipoprotein (ox-LDL) was used to construct the VEC injury model in vitro. The expression levels of circ_0004104 and miR-100 were measured by quantitative real-time polymerase chain reaction. The proliferation of VECs was determined using 3-(45)-dimethylthiahiazo (-z-y1)-35-di-phenytetrazoliumromide assay and 5-ethynyl-2'-deoxyuridine staining assay. VEC apoptosis rate was assessed using flow cytometry, and caspase-3 activity was measured using a Caspase-3 Assay Kit. The protein expression levels of Ki-67, cleaved-caspase3, and tumor necrosis factor-α-induced protein 8 (TNFAIP8) were detected by western blot analysis. Furthermore, enzyme-linked immunosorbent assay was performed to assess the concentrations of inflammatory cytokines. In addition, the relationship between miR-100 and circ_0004104 or TNFAIP8 was confirmed by dual-luciferase reporter assay and biotin-labeled RNA pull-down assay. Our results revealed that circ_0004104 was upregulated and miR-100 was downregulated in patients with CAD and ox-LDL-induced VECs. Ox-LDL could inhibit the proliferation and promote the apoptosis and inflammation of VECs to induce VEC injury. However, silenced circ_0004104 could alleviate VEC injury induced by ox-LDL. Moreover, we found that circ_0004104 could sponge miR-100 and a miR-100 inhibitor could reverse the inhibition effect of circ_0004104 knockdown on ox-LDL-induced VEC injury. In addition, TNFAIP8 was a target of miR-100, and miR-100 alleviated ox-LDL-induced VEC injury by targeting TNFAIP8. Our data suggested that circ_0004104 promoted ox-LDL-induced VEC injury by the miR-100/TNFAIP8 axis, indicating that circ_0004104 might be a potential biomarker for CAD treatment.

中文翻译：

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circ_0004104 的敲除通过调节 miR-100/TNFAIP8 轴减轻氧化低密度脂蛋白诱导的血管内皮细胞损伤。

冠状动脉疾病（CAD）是一种常见的心血管疾病，主要是由于动脉粥样硬化引起的血管内皮细胞（VEC）损伤。环状RNA已被证明参与多种疾病的调节。然而，circ_0004104在CAD中的作用和机制尚不清楚。采用氧化低密度脂蛋白（ox-LDL）体外构建VEC损伤模型。通过定量实时聚合酶链反应测量circ_0004104和miR-100的表达水平。使用 3-(45)-dimethylthiahiazo (-z-y1)-35-di-phenytetrazoliumromide 测定和 5-ethynyl-2'-deoxyuridine 染色测定确定 VEC 的增殖。使用流式细胞术评估 VEC 凋亡率，并使用 Caspase-3 Assay Kit 测量 caspase-3 活性。Ki-67、cleaved-caspase3、通过蛋白质印迹分析检测肿瘤坏死因子-α诱导蛋白8（TNFAIP8）。此外，进行酶联免疫吸附测定以评估炎性细胞因子的浓度。此外，通过双荧光素酶报告基因分析和生物素标记的 RNA 下拉分析证实了 miR-100 与 circ_0004104 或 TNFAIP8 之间的关系。我们的结果显示，在 CAD 和 ox-LDL 诱导的 VEC 患者中，circ_0004104 上调，miR-100 下调。Ox-LDL可以抑制VECs增殖，促进VECs凋亡和炎症，从而诱导VECs损伤。然而，沉默的 circ_0004104 可以减轻 ox-LDL 诱导的 VEC 损伤。而且，我们发现 circ_0004104 可以海绵 miR-100，而 miR-100 抑制剂可以逆转 circ_0004104 敲低对 ox-LDL 诱导的 VEC 损伤的抑制作用。此外，TNFAIP8 是 miR-100 的靶点，miR-100 通过靶向 TNFAIP8 减轻 ox-LDL 诱导的 VEC 损伤。我们的数据表明 circ_0004104 通过 miR-100/TNFAIP8 轴促进 ox-LDL 诱导的 VEC 损伤，表明 circ_0004104 可能是 CAD 治疗的潜在生物标志物。