Mizutani T, Nishikawa Y, Adachi H, Enomoto T, Ikegami H, Kurachi H, Nomura T, Miyake A
Department of Obstetrics and Gynecology, Osaka University Medical School, Japan.
J Clin Endocrinol Metab. 1994 Apr;78(4):950-4. doi: 10.1210/jcem.78.4.8157726.
Estrogen has various effects on adipose tissue. Although the presence of estrogen receptor (ER) has been demonstrated in rat adipose tissue and adipocytes, ER has not been identified in human adipose tissue. In this study, we demonstrated the existence of ER protein and ER messenger RNA (mRNA) in human sc adipose tissue and adipocytes. The cytosol fraction of human adipose tissue was partially purified by ammonium sulfate precipitation, and the presence of ER protein was analyzed by [3H]estradiol (E2) binding assay and Western blot analysis. [3H]E2 binding assay showed a low specific binding due to high nonspecific binding, and the dissociation constant (Kd) and maximal binding sites could not be obtained by Scatchard analysis. Western blots, however, showed the presence of ER protein in both the partially purified cytosol and nuclear fractions of human adipose tissue. The mol wt of ER in both fractions was approximately 66,000. Furthermore, Northern blot analysis of total RNA samples isolated from human adipose tissue showed the expression of ER mRNA at 6.2 kilobase in size. ER mRNA was also identified in isolated human adipocytes by the reverse transcription and polymerase chain reaction. These results indicated that both ER protein and ER mRNA are expressed in human adipocytes, suggesting that the effect of estrogen on human adipose tissues might involve a direct action.
雌激素对脂肪组织有多种作用。虽然已在大鼠脂肪组织和脂肪细胞中证实存在雌激素受体（ER），但在人类脂肪组织中尚未鉴定出ER。在本研究中，我们证实在人类皮下脂肪组织和脂肪细胞中存在ER蛋白和ER信使核糖核酸（mRNA）。通过硫酸铵沉淀对人类脂肪组织的胞质溶胶部分进行部分纯化，并通过[3H]雌二醇（E2）结合试验和蛋白质印迹分析来分析ER蛋白的存在情况。[3H]E2结合试验显示由于非特异性结合较高导致特异性结合较低，并且通过Scatchard分析无法获得解离常数（Kd）和最大结合位点。然而，蛋白质印迹显示在人类脂肪组织部分纯化的胞质溶胶和核部分中均存在ER蛋白。两个部分中ER的分子量约为66,000。此外，对从人类脂肪组织分离的总RNA样本进行的Northern印迹分析显示大小为6.2千碱基的ER mRNA的表达。通过逆转录和聚合酶链反应在分离的人类脂肪细胞中也鉴定出了ER mRNA。这些结果表明ER蛋白和ER mRNA在人类脂肪细胞中均有表达，提示雌激素对人类脂肪组织的作用可能涉及直接作用。
