Estrogen and tamoxifen metabolites protect smooth muscle cell membrane phospholipids against peroxidation and inhibit cell growth
Estrogen and tamoxifen metabolites protect smooth muscle cell membrane phospholipids against peroxidation and inhibit cell growth
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DOI：
10.1161/01.res.84.2.229
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发表时间：
1999-02-05
影响因子：
20.1
通讯作者：
Kagan, VE
中科院分区：
文献类型：
--
作者：
Dubey, RK;Tyurina, YY;Kagan, VE
本研究的目的是验证一种假设，即抗氧化剂雌激素通过一种独立于雌激素受体的机制保护停留在血管平滑肌细胞质膜上的磷脂免受过氧化和过氧化诱导的细胞生长和迁移。通过用顺式羟基苯甲酸(一种易受过氧化作用的脂肪酸，可使其荧光特性减弱)标记的大鼠主动脉血管平滑肌细胞提取的磷脂进行高效液相分析，评价了膜磷脂的过氧化作用。细胞与过氧化自由基供体2，2‘-偶氮-2，4-二甲基戊腈(AMVN)孵育2小时，可引起所有被测膜磷脂的过氧化。用50-5000 ng/mL2-羟基雌二醇(强抗氧化剂但弱雌激素受体配体)或4-羟基三苯氧胺(强抗氧化剂但强雌激素受体配体)处理细胞15分钟可减弱这种作用，但不能被雌酮或屈洛昔芬(两者均为弱抗氧化剂但强雌激素受体配体)所减弱。生理浓度(0.3 ng/mL)的2-羟基雌二醇或药理相关浓度的4-羟基三苯氧胺(40 ng/mL4-羟基三苯氧胺)对AMVN诱导的磷脂过氧化作用也有一定的抑制作用，2-羟基雌二醇和4-羟基三苯氧胺对AMVN诱导的膜脂过氧化作用与维生素E的抗氧化剂2，2，5，7，8-五甲基-6-羟色胺一样有效。此外，生理浓度的2-羟基雌二醇，而不是雌酮，以及药理上相关的浓度的4-羟基三苯氧胺可减弱AMVM诱导的DNA合成、细胞增殖和细胞迁移。这些研究表明，在血管平滑肌细胞中，抗氧化剂雌激素通过一种非雌激素受体依赖的机制，减轻膜磷脂的过氧化以及过氧化诱导的细胞生长和迁移。
The goal of this study was to test the hypothesis that antioxidant estrogens, by a mechanism independent of the estrogen receptor, protect phospholipids residing in the plasma membrane of vascular smooth muscle cells from peroxidation and peroxidation-induced cell growth and migration. Peroxidation of membrane phospholipids was assessed by HPLC analysis of phospholipids extracted from rat aortic vascular smooth muscle cells prelabeled with cis-parinaric acid (a fatty acid that is susceptible to peroxidation, which quenches its fluorescent properties). Incubation of cells for 2 hours with the peroxyl radical donor 2,2'-azobis-2,4-dimethylvaleronitrile (AMVN) caused peroxidation of all measured membrane phospholipids. This effect was attenuated by pretreating cells for 15 minutes with 50 to 5000 ng/mL of 2-hydroxyestradiol (strong antioxidant but weak estrogen-receptor ligand) or 4-hydroxytamoxifen (strong antioxidant and potent estrogen-receptor ligand), but not by estrone or droloxifene (both weak antioxidants but potent estrogen-receptor ligands). Moreover, pretreatment of cells for 20 hours with physiological concentrations (0.3 ng/mL) of 2-hydroxyestradiol or pharmacologically relevant concentrations of 4-hydroxytamoxifen (40 ng/mL) also decreased AMVN-induced phospholipid peroxidation, Both 2-hydroxyestradiol and 4-hydroxytamoxifen were as effective as 2,2,5,7,8-pentamethyl-6-hydrochromane (an antioxidant homolog of vitamin E) in attenuating AMVN-induced peroxidation of membrane phospholipids. Also, physiological concentrations of 2-hydroxyestradiol, but not estrone, and pharmacologically relevant concentrations of 4-hydroxytamoxifen attenuated AMVM-induced DNA synthesis, cell proliferation, and cell migration. These studies demonstrate in vascular smooth muscle cells that antioxidant estrogens via a non-estrogen receptor-dependent mechanism attenuate peroxidation of membrane phospholipids and peroxidation-induced cell growth and migration.