Zhang Yan-lin, Cao Yong-jun, You Shou-jiang, Li Rui-xia, Liu Hui-hui, Liu Chun-feng
Department of Neurology, Second Affiliated Hospital of Soochow University, Suzhou 215004, China.
Zhonghua Yi Xue Za Zhi. 2010 Oct 26;90(39):2792-6.
To investigate the role of autophagy in oxidized low density lipoprotein (ox-LDL) induced injury of human umbilical vein endothelial cells (HUVEC).
The cultured HUVECs were randomly divided into four groups of control, ox-LDL, ox-LDL + rapamycin and ox + 3-methyladenine (3-MA). The cells were used to detect the ratio of LC3-II/LC3-I by Western blot while the proliferation and apoptosis of cells measured by MTT and flow cytometry. The lactate dehydrogenase (LDH) activity and endothelin-1 (ET-1) content in the supernatant were detected with enzyme linked immunosorbent assay.
The Ox-LDL treatment up-regulated the ratio of LC3-II/LC3-I in HUVEC (P < 0.01). It increased the activity of LDH (P < 0.01)and content of ET-1 (P < 0.05) in the supernatant. Also it induced the proliferation (P = 0.028) and apoptosis (P < 0.05) of cells. The autophagic inducer rapamycin increased the up-regulation of autophagic level induced by ox-LDL, decreased the activity of LDH and content of ET-1 (P < 0.05) and inhibited the ox-LDL-induced proliferation of cells. Conversely, the autophagic inhibitor 3-MA decreased the elevation of LC3-II/LC3-I induced by ox-LDL (P < 0.01) and increased the cell apoptosis and death.
Ox-LDL exposure can increase the secretion of LDH and ET-1 and induce the proliferation and apoptosis of cells so as to cause a harmful effect in the survival of HUVEC. The injury may be reduced by rapamycin, an autophagic inducer, and elevated by the autophagic inhibitor 3-MA.
探讨自噬在氧化型低密度脂蛋白（ox-LDL）诱导的人脐静脉内皮细胞（HUVEC）损伤中的作用。
将培养的HUVEC随机分为对照组、ox-LDL组、ox-LDL + 雷帕霉素组和ox + 3-甲基腺嘌呤（3-MA）组。采用蛋白质免疫印迹法检测细胞中LC3-II/LC3-I的比值，采用MTT法和流式细胞术检测细胞的增殖和凋亡情况。采用酶联免疫吸附测定法检测上清液中乳酸脱氢酶（LDH）活性和内皮素-1（ET-1）含量。
ox-LDL处理可上调HUVEC中LC3-II/LC3-I的比值（P < 0.01）。它增加了上清液中LDH的活性（P < 0.01）和ET-1的含量（P < 0.05）。此外，它还诱导了细胞的增殖（P = 0.028）和凋亡（P < 0.05）。自噬诱导剂雷帕霉素增加了ox-LDL诱导的自噬水平上调，降低了LDH的活性和ET-1的含量（P < 那么5），并抑制了ox-LDL诱导的细胞增殖。相反，自噬抑制剂3-MA降低了ox-LDL诱导的LC3-II/LC3-I升高（P < 0.01），并增加了细胞凋亡和死亡。
暴露于ox-LDL可增加LDH和ET-1的分泌，诱导细胞增殖和凋亡，从而对HUVEC的存活产生有害影响。自噬诱导剂雷帕霉素可减轻这种损伤，而自噬抑制剂3-MA则会加重这种损伤。
