[关键词]
[摘要]
目的 探讨丹酚酸 C 通过激活 PPARα 信号通路改善 db/db 小鼠脂质代谢紊乱的作用及分子机制。 方法 将 C57BLKS/J(db/db)小鼠随机分为 5 组,每组 10 只,分别为模型组(db/db 组)、辛伐他汀组(阳性 对照药,10 mg·kg-1 )、丹酚酸 C 低剂量组(5 mg·kg-1 )、丹酚酸 C 中剂量组(10 mg·kg-1 )和丹酚酸 C 高剂量组 (20 mg·kg-1 );另外,选取同窝 db/m 小鼠 10 只,作为正常对照组(db/m 组)。各给药组小鼠按照上述剂量灌胃 给予相应药物,每日 1 次,连续给药 8 周。检测小鼠血清总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固 醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)水平以及肝脏组织 TC、TG 含量。采用油红 O 染色法观察肝脏组 织中脂质蓄积情况。通过网络药理学方法筛选丹酚酸 C 干预脂质代谢紊乱的潜在作用靶点,并进行 GO 功能注 释及 KEGG 信号通路富集分析;Western Blot 法检测小鼠肝脏 PPARα、CPT1-α 及 PGC-1α 蛋白表达水平; qPCR 法检测小鼠肝脏 PPARα、ACOX1、CPT1- α、PGC-1α、SREBP-1、ACC、FABP-1、ADIPOR、ACO mRNA 表达水平;构建丹酚酸 C 干预脂质代谢紊乱的潜在作用靶点蛋白互作(PPI)网络,筛选 PPARα 通路上 游潜在核心靶点,并与丹酚酸 C 进行分子对接验证。结果 (1)动物实验研究:与正常对照组比较,模型组小 鼠的血清 TC、TG 及 LDL-C 水平均显著升高(P<0.01),HDL-C 水平显著降低(P<0.01);肝脏组织可见明显 的脂质蓄积,脂滴阳性面积显著增加(P<0.01),肝脏组织 TC、TG 水平显著升高(P<0.01);肝脏组织 PPARα、CPT1-α、PGC-1α 蛋白水平明显降低(P<0.05);肝脏组织中与脂肪酸 β-氧化、转运及线粒体转运过 程相关的 PPARα、ACOX1、CPT1-α、PGC-1α、FABP-1、ADIPOR、ACO mRNA 表达水平均显著下降(P< 0.01),与脂质合成相关的 SREBP-1、ACC mRNA 表达水平显著升高(P<0.01)。与模型组比较,丹酚酸 C 中、 高剂量组小鼠的血清 TC、TG、LDL-C 水平显著降低(P<0.05、P<0.01),肝脏脂滴阳性面积显著减少(P< 0.05,P<0.01),肝脏组织 TC、TG 水平显著降低(P<0.01),PPARα、CPT1-α、PGC-1α、FABP-1、ACO mRNA 表达水平均显著上调(P<0.01),ACC mRNA 表达水平显著下调(P<0.01);丹酚酸 C 高剂量组小鼠的血 清 HDL-C 水平明显升高(P<0.05),肝脏组织 PPARα、CPT1-α、PGC-1α 蛋白表达水平显著升高(P<0.01), ACOX1、ADIPOR mRNA 表达水平显著上调(P<0.01),SREBP-1 mRNA 表达水平显著下调(P<0.01)。(2)网络 药理学分析:得到丹酚酸 C 干预脂质代谢紊乱的潜在作用靶点 75 个,主要参与脂肪酸代谢、类固醇代谢等脂 质代谢相关生物学过程,PPAR 信号通路可能是丹酚酸 C 调节脂质代谢的关键通路之一。筛选得到 30 个核心 靶点,丹酚酸 C 可与 PPARα 通路上游关键调控蛋白靶点 FASN、NR3C1、RXRA 稳定结合,结合能分别为-10.2、 -8.4、-8.9 kcal·mol-1 。结论 丹酚酸 C 可通过激活 PPARα 信号通路,上调其下游关键因子 CPT1-α、PGC-1α 等的表达,促进脂肪酸 β-氧化及能量代谢,抑制肝脏脂质蓄积,从而改善 db/db 小鼠脂质代谢紊乱状态。
[Key word]
[Abstract]
Objective To investigate the effect and molecular mechanism of salvianolic acid C in improving lipid metabolism disorder in db/db mice by activating the PPARα signaling pathway. Methods C57BLKS/J (db/db) mice were randomly divided into 5 groups (n=10 per group): model group (db/db group), simvastatin group (positive control,10 mg·kg-1 ),and low-dose (5 mg·kg-1 ),medium-dose (10 mg·kg-1 ),and high-dose (20 mg·kg-1 )salvianolic acid C groups. Additionally,10 littermate db/m mice were selected as the normal control group (db/m group). Mice in each administration group were given the corresponding drugs by gavage once daily for 8 consecutive weeks. Serum levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C),as well as hepatic TC and TG contents,were measured. Hepatic lipid accumulation was observed using Oil Red O staining. Network pharmacology was employed to screen potential targets of salvianolic acid C for intervening in lipid metabolism disorder,followed by GO function annotation and KEGG pathway enrichment analysis. Western Blot was used to detect the protein expression levels of PPARα,CPT1-α,and PGC-1α in mouse liver. qPCR was used to detect the mRNA expression levels of PPARα,ACOX1,CPT1-α,PGC-1α,SREBP-1, ACC,FABP-1,ADIPOR,and ACO in mouse liver. A protein-protein interaction (PPI) network of potential targets of salvianolic acid C for lipid metabolism disorder was constructed to screen upstream core targets of the PPARα pathway, and molecular docking was performed to validate the binding of salvianolic acid C with these targets. Results (1) Animai experiment: Compared with the normal control group, the model group exhibited significantly increased serum levels of TC,TG,and LDL-C (P<0.01),and significantly decreased HDL-C levels (P<0.01). Marked hepatic lipid accumulation was observed,with a significant increase in the positive area of lipid droplets (P< 0.01) and significantly elevated hepatic TC and TG levels (P<0.01). Hepatic protein levels of PARα,CPT1-α,and PGC-1α were significantly decreased (P<0.05). The mRNA expression levels of PPARα,ACOX1,CPT1-α,PGC-1α, FABP-1,ADIPOR,and ACO,which are involved in fatty acid β-oxidation,transport,and mitochondrial transport processes, were significantly decreased (P<0.01), while the mRNA expression levels of lipid synthesis-related SREBP-1 and ACC were significantly increased (P<0.01). Compared with the model group,the medium- and highdose salvianolic acid C groups showed significantly reduced serum TC,TG,and LDL-C levels (P<0.05,P<0.01), a significantly reduced positive area of hepatic lipid droplets (P<0.05,P<0.01),and significantly decreased hepatic TC and TG levels (P<0.01). The mRNA expression levels of PPARα,CPT1-α,PGC-1α,FABP-1,and ACO were significantly upregulated (P<0.01),while ACC mRNA expression was significantly downregulated (P<0.01). In the high-dose salvianolic acid C group, hepatic protein expression levels of PPARα, CPT1- α, and PGC-1α were significantly increased (P<0.01), ACOX1,ADIPOR mRNA expression was significantly upregulated (P<0.01), and SREBP-1 mRNA expression was significantly downregulated (P<0.01).(2) Network pharamacology:A total of 75 potential targets of salvianolic acid C for intervening in lipid metabolism disorder were identified, which were primarily involved in lipid metabolism-related biological processes such as fatty acid metabolism and steroid metabolism. The PPAR signaling pathway emerged as one of the key pathways through which salvianolic acid C may regulate lipid metabolism. Thirty core targets were screened,and salvianolic acid C was shown to stably bind to the key upstream regulatory protein targets of the PPARα pathway,FASN,NR3C1,and RXRA,with binding energies of -10.2,-8.4, and -8.9 kcal·mol-1 ,respectively. Conclusion Salvianolic acid C ameliorates lipid metabolism disorder in db/db mice by activating the PPARα signaling pathway,upregulating the expression of its key downstream factors such as CPT1-α and PGC-1α, thereby promoting fatty acid β -oxidation and energy metabolism, and inhibiting hepatic lipid accumulation.
[中图分类号]
R285.5
[基金项目]
国家自然科学基金项目(82474495,82174267);河南省高校科技创新人才支持项目(24HASTIT072);河南省中医药科研专项课题 (2023ZYZD15);河南省高等学校大学生创新训练计划项目(202410471014)。