[关键词]
[摘要]
目的 探讨黄连温胆汤含药血清对氧化低密度脂蛋白(ox-LDL)诱导的巨噬细胞泡沫化的影响及作用机 制。方法 采用 CCK-8 法筛选 ox-LDL 及黄连温胆汤含药血清的最佳作用浓度和时间。采用 nesfatin-1 SiRNA 及阴性对照 SiRNA 进行 RAW264.7 巨噬细胞转染,设立对照组、nesfatin-1 SiRNA 组和阴性对照 SiRNA 组,采 用 Western Blot 法评估沉默效果。将 RAW264.7 巨噬细胞分为对照组、模型组、空白血清组、黄连温胆汤组、 黄连温胆汤+阴性对照 SiRNA 组、黄连温胆汤+nesfatin-1 SiRNA 组。采用油红 O 染色观察泡沫细胞形成情况, 比色法检测细胞内总胆固醇(TC)和游离胆固醇(FC)含量,计算胆固醇酯(CE)和胆固醇酯化率(CER),并通过 RT-qPCR 和 Western Blot 法分别检测 nesfatin-1、LKB1、AMPK、HMGCR、SREBP1c、CD36 和 LOX-1 的 mRNA 及蛋白表达水平。结果 CCK-8 筛选结果表明,ox-LDL 的最佳作用浓度为 80 µg·mL-1 ,作用时间为 24 h;黄连温胆汤含药血清的最佳浓度为 15%,作用时间为 24 h。与对照组比较,nesfatin-1 SiRNA 组 nesfatin-1 蛋白表达水平下降(P<0.05),阴性对照 SiRNA 组 nesfatin-1 蛋白表达水平无明显改变(P>0.05)。 与对照组比较,模型组和空白血清组的红色脂滴面积增大(P<0.05),TC、FC、CE 和 CER 水平升高(P< 0.05), nesfatin-1、 LKB1 mRNA 和 蛋 白 表 达 水 平 下 调(P<0.05), pAMPK/AMPK 比 值 下 调(P<0.05), HMGCR、SREBP1c、CD36、LOX-1 mRNA 及蛋白表达水平上调(P<0.05)。与模型组比较,空白血清组无明 显改变(P>0.05);黄连温胆汤组、黄连温胆汤+阴性对照 SiRNA 组及黄连温胆汤+nesfatin-1 SiRNA 组红色脂 滴面积减小(P<0.05),TC、FC、CE 和 CER 水平降低(P<0.05),nesfatin-1、LKB1 mRNA 及蛋白表达水平上 调(P<0.05),pAMPK/AMPK 比值上调(P<0.05),HMGCR 蛋白表达水平下调(P<0.05),SREBP1c、CD36、 LOX-1 mRNA 及蛋白表达水平下调(P<0.05)。与黄连温胆汤组比较,黄连温胆汤+阴性对照 SiRNA 组无明显 改变(P>0.05);黄连温胆汤+nesfatin-1 SiRNA 组脂滴面积增大(P<0.05),TC、FC、CE 和 CER 含量增加 (P<0.05),nesfatin-1、LKB1 mRNA 和蛋白表达水平降低(P<0.05),pAMPK/AMPK 比值降低(P<0.05), HMGCR、SREBP1c、CD36、LOX-1 mRNA 及蛋白表达水平增高(P<0.05)。结论 Ox-LDL 诱导的泡沫细胞 中 nesfatin-1 表达下调。黄连温胆汤含药血清通过上调 nesfatin-1 表达,促进 LKB1 表达,激活 AMPK 信号通 路、抑制 HMGCR 和 SREBP1c 表达、减少胆固醇的合成,下调 CD36 和 LOX-1 表达、减少脂质的摄取和内吞, 从而降低胞内胆固醇水平,抑制 ox-LDL 诱导的巨噬细胞泡沫化。
[Key word]
[Abstract]
Objective To investigate the effect of Huanglian Wendan Decoction (HLWDD)-mediated serum on oxidized low-density lipoprotein (ox-LDL)-induced macrophage foam cell formation and to elucidate its underlying mechanism. Methods The optimal concentration and time for ox-LDL and HLWDD-mediated serum were screened using the CCK-8 assay. RAW264.7 macrophages were transfected with nesfatin-1 SiRNA or negative control SiRNA,and the silencing efficacy was evaluated by Western Blot in the control group,nesfatin-1 SiRNA group,and negative control SiRNA group. RAW264.7 macrophages were divided into six groups:control,model,blank serum,HLWDD,HLWDD + negative control SiRNA,and HLWDD + nesfatin-1 SiRNA groups. Foam cell formation was observed by Oil Red O staining. Intracellular total cholesterol (TC) and free cholesterol (FC) contents were measured colorimetrically to calculate cholesterol ester (CE) content and cholesterol esterification rate (CER). The mRNA and protein expression levels of nesfatin-1, LKB1, AMPK, HMGCR, SREBP1c, CD36, and LOX-1 were detected by RT-qPCR and Western Blot,respectively. Results The CCK-8 assay indicated that the optimal conditions were 80 µg·mL-1 ox-LDL and 15% HLWDD-mediated serum,both for 24 hours. Compared with the control group,nesfatin-1 protein expression decreased in the nesfatin-1 SiRNA group (P<0.05) but showed no significant change in the negative control SiRNA group (P>0.05). Compared with the control group,the model and blank serum groups exhibited an increased area of red lipid droplets (P<0.05), elevated levels of TC, FC, CE, and CER (P<0.05), downregulated mRNA and protein expression of nesfatin-1 and LKB1(P<0.05),a decreased pAMPK/AMPK ratio (P<0.05),and upregulated mRNA and protein expression of HMGCR, SREBP1c, CD36, and LOX-1(P<0.05). Compared with the model group,the blank serum group showed no significant changes (P>0.05). The HLWDD,HLWDD + negative control SiRNA,and HLWDD + nesfatin-1 SiRNA groups showed a decreased area of red lipid droplets (P<0.05),reduced levels of TC,FC,CE,and CER (P<0.05),upregulated mRNA and protein expression of nesfatin-1 and LKB1(P< 0.05),an increased pAMPK/AMPK ratio (P<0.05),downregulated protein expression of HMGCR (P<0.05),and downregulated mRNA and protein expression of SREBP1c, CD36, and LOX-1 (P<0.05). Compared with the HLWDD group,the HLWDD + negative control SiRNA group showed no significant changes (P>0.05),while the HLWDD + nesfatin-1 SiRNA group displayed an increased area of lipid droplets (P<0.05),elevated levels of TC, FC, CE, and CER (P<0.05), decreased mRNA and protein expression of nesfatin-1 and LKB1(P<0.05), a reduced pAMPK/AMPK ratio (P<0.05), and increased mRNA and protein expression of HMGCR, SREBP1c, CD36,and LOX-1(P<0.05). Conclusion The expression of nesfatin-1 is downregulated in ox-LDL-induced foam cells. HLWDD-mediated serum inhibits ox-LDL-induced macrophage foam cell formation by upregulating nesfatin-1 expression. This not only promotes LKB1 expression,activates the AMPK signaling pathway,and suppresses HMGCR and SREBP1c expression to reduce cholesterol synthesis, but also downregulates CD36 and LOX-1 expression to decrease lipid uptake and endocytosis,thereby lowering intracellular cholesterol levels.
[中图分类号]
R285.5
[基金项目]
国家自然科学基金面上项目(82274522);王红天津市名中医传承工作室项目(津卫中[2024]61号)。