摘要
目的：探讨氧化低密度脂蛋白（ｏｘｉｄｉｚｅｄ ｌｏｗ ｄｅｎｓｉｔｙｌｉｐｏｐｒｏｔｅｉｎ，ｏｘＬＤＬ） 血管内皮受体（ｌｅｃｔｉｎｌｉｋｅ ｏｘＬＤＬｒｅｃｅｐｔｏｒ，ＬＯＸ１）在ｏｘＬＤＬ致内皮细胞损伤中的作用及其机制。方法：放射配基结合及竞争抑制实验检测人脐静脉内皮细胞（ｈｕｍａｎ ｕｍｂｉｌｉｃａｌｖｅｉｎ ｅｎｄｏｔｈｅｌｉａｃｅｌｌｓ，ＨＵＶＥＣｓ）存在ＬＯＸ１ 的高亲和位点，采用倒置相差显微镜观察细胞形态的改变，测定细胞及上清乳酸脱氢酶（ｌａｃｔｉｃ ｄｅｈｙｄｒｏｇｅｎａｓｅ，ＬＤＨ）活性，计算细胞死亡率，发色底物法检测内皮细胞培养液中的组织纤溶酶原激活物（ｔｉｓｓｕｅ ｐｌａｓｍｉｎｏｇｅｎ ａｃｔｉｖａｔｏｒ，ｔＰＡ） 和纤溶酶原激活物抑制剂（ｐｌａｓｍｉｎｏｇｅｎａｃｔｉｖａｔｏｒｉｎｈｉｂｉｔｏｒ１ ，ＰＡＩ１）的活性； 反转录聚合酶链反应检测ＬＯＸ１ ｍＲＮＡ 表达水平，Ｃａ２＋ 示踪测定细胞钙转运功能。结果：ＨＵＶＥＣｓ 存在ＬＯＸ１ 的高亲和位点［Ｂｍａｘ（５４ ±２０） ｎｇ／１０６ ｃｅｌｌｓ，Ｋｄ（２．０ ±０．６） ×１０－８ ｍｏｌ·Ｌ－ １］ ，单纯加入ｏｘＬＤＬ作用２４ ｈ ?
Objective:To explore the role and mechanism of lectin like ox LDL receptor (LOX1) in injury of endothelial cells by oxidized low density lipoprotein (ox LDL). Methods:Radioligand binding assessed if human umbilical vein endothelial cells (HUVECs) possessed high affinity binding sites for LOX1. The morphological changes of endothelial cells were observed with inverted phasecontrast microscope; the mortality of HUVECs was assessed by the measurement of LDH, the dysfunction of HUVECs was determined by measuring tissue plasminogen activator(t PA) and plasminogen activator inhibitor 1(PAI 1)activity with Chromogenix;LOX1 mRNA expression was detected by reverse transcription polymerase chain reaction(RT PCR),and the calcium transportation of endothelial cells was measured. Results: HUVECs possessed high affinity binding sites for LOX1[Bmax(54.5±20.3) ng/10 6 cell, Kd(2.0±0.6)×10 -8 mol·L -1 ]. Incubation of ox LDL induced endothelial cells contraction and cellular membrane rupture, enhanced the mortality of HUVECs, increased PAI 1 activity 3 times more than control per 24 h per 10 5 cells ( P <0.05), enhanced LOX1 mRNA expression and the calcium uptaking, but had only minor effects on t PA activity and calcium releasing of endothelial cells. When HUVECs were incubated with ox LDL as well as the inhibitor of LOX1, polyinosinic acid, these changes of endothelial cells were attenuated. Conclusion: There are high affinity binding site to LOX1 in HUVECs. Ox LDL upregulated LOX1 mRNA expression in a concentration dependent manner. LOX1 may mediate the injury of HUVECs by ox LDL ,and the rise of calcium uptaking may involve the injury of endothelial cells by LOX1 mediated.
出处
《北京医科大学学报》
CSCD
1999年第6期547-551,共5页
Journal of Peking University(Health Sciences)
关键词
OX-LDL
血管内皮损伤
低密度脂蛋白
Receptor
lipoprotein
Lipoproteins
LDL
Endothelial
vascular/pathol
Plasminogen activators/anal
Plasminogen inactivators/anal
Calcium/metab
