大蒜素通过抑制凝集素样氧化低密度脂蛋白受体-1减轻氧化低密度脂蛋白诱导的血管内皮细胞凋亡

ALLICIN PROTECTS VASCULAR ENDOTHELIAL CELLS AGAINST OXIDIZED LOW DENSITY LIPOPROTEIN INDUCED APOPTOSIS BY INHIBITING LECTIN-LIKE OXIDIZED LOW DENSITY LIPOPROTEIN RECEPTOR-1

目的研究大蒜素对氧化低密度脂蛋白(oxidized low-density lipoprotein,ox-LDL)诱导的血管内皮细胞凋亡的抑制作用,并探讨其可能的分子机制。方法体外培养人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVECs),给予大蒜素(12.5、25和50 mg/L)、4-苯丁酸(4-phenylbutyric acid,PBA,4 mmol/L)或抗凝集素样氧化低密度脂蛋白受体-1(lectin-like oxidized low density lipoprotein receptor-1,LOX-1)单克隆抗体(4 mg/L)预处理lh,再加入ox-LDL(100 mg/L)继续培养24h。分别采用MTT法和Annexin V-FITC/PI双染法检测细胞活力和细胞凋亡;说剂盒检测培养基乳酸脱氢酶(lactic dehydrogenase,LDH)和细胞内caspase-3活性。Western blot法测定LOX-1及内质网应激(endoplasmic reticulum stress,ERS)关键分子双链RNA依赖的蛋白激酶样ER激酶(double-stranded RNA-activated protein kinase-like ER kinase,PERK)磷酸化水平和促凋亡蛋白caspase-12表达变化。结果与ERS抑制剂PBA相似,大蒜素显著减轻ox-LDL所诱导的HIUVECs损伤,表现为细胞活力增加(P<0.05或P<0.01),LDH漏出、凋亡率和caspase-3活性降低(P<0.05或P<0.01)。大蒜素明显抑制ox-LDL所致的LOX-1上调(P<0.05或P<0.01)。另外,与PBA相似,大蒜素明显抑制ox-LDL所诱导的PERK磷酸化和caspase-12活化(P<0.05或P<0.01)。抗LOX-1单抗可抑制ox-LDL所致的caspase-12活化(P<0.05)。结论大蒜素可减轻ox-LDL所致的HUVECs凋亡,其机制可能与抑制LOX-1上调继而减轻ERS-caspase-12途径活化有关。

Objective To investigate the inhibitory effect of allicin on oxidized low density lipoprotein(ox-LDL)-induced vascular endothelial cell apoptosis and the underlying molecular mechanisms.Methods Human umbilical vein endothelial cells(HUVECs)were preincubated with allicin(12.5、25 and 50 mg/L),4-phenylbutyric acid(PBA,4 mmol/L)or anti-lectin-like oxidized low density lipoprotein receptor-1 monoclonal antibody(anti-LOX-1 mAb,4 mg/L)for 1 h and then exposed to ox-LDL(100 mg/L)for 24 h.Cell viability and apoptosis were determined by MTT assay and Annexin V-FITC/PI apoptosis detection kit,respectively.Lactic dehydrogenase(LDH)activity in the medium and caspase-3 activity in the cells were measured by detection kits.The protein levels of LOX-1 and two key molecules associated with endoplasmic reticulum stress(ERS)including double-stranded RNA-activated protein kinase-like ER kinase(PERK)and caspase-12 were measured by Western blotting.Results In an action similar to PBA(an ERS inhibitor),allicin reduced ox-LDL-induced HUVEC injury,as indicated by increased cell viability and decreased LDH leakage,apoptosis and caspase-3 activation.Allicin significantly inhibited ox-LDL-induced LOX-1 upregulation.Moreover,allicin significantly suppressed ox-LDL-induced PERK phosphorylation and caspase-12 activation.Furthermore,anti-LOX-1 mAb reduced ox-LDL-induced caspase-12 activation.Conclusion Allicin may inhibit ox-LDL-induced HUVEC apoptosis,and the mechanism is partially by suppressing LOX-1 upregulation and inhibiting the activation of ERS-caspase-12 pathway.