Tan Bee K, Chen Jing, Lehnert Hendrik, Kennedy Richard, Randeva Harpal S
Endocrinology and Metabolism Group, Clinical Sciences Research Institute, Warwick Medical School, University of Warwick, Coventry CV4 7AL, United Kingdom.
J Clin Endocrinol Metab. 2007 Jul;92(7):2764-72. doi: 10.1210/jc.2007-0091. Epub 2007 Apr 24.
Polycystic ovary syndrome (PCOS) is associated with insulin resistance and obesity. Recent studies have shown that serum retinol-binding protein 4 (RBP4) levels increase with obesity. Currently, no data exist on the relative expression of RBP4 in either serum or adipose tissue of PCOS women.
mRNA expression of RBP4 from sc and omental (om) adipose tissue and sc adipocytes in overweight PCOS women were compared with matched controls; RBP4 protein in adipose tissue and serum RBP4 levels were also assessed. Additionally, we studied the effects of testosterone, 17beta-estradiol, androstenedione, and dehydroepiandrosterone sulfate on RBP4 expression in adipose tissue explants.
Real-time RT-PCR and Western blotting were used to assess the relative mRNA and protein expression of RBP4. Biochemical measurements were also performed.
Compared with controls, there was significant up-regulation of RBP4 mRNA in sc (P < 0.05) and om (P < 0.01) adipose tissue as well as isolated sc adipocytes (P < 0.01) of PCOS women. In addition to elevated serum RBP4 levels in PCOS women (P < 0.05), RBP4 protein levels were significantly greater in sc and om adipose tissue of PCOS women (P < 0.05 and P < 0.05, respectively). Furthermore, in human sc and om adipose tissue explants, 17beta-estradiol significantly increased RBP4 mRNA expression, protein levels, and secretion into the culture media (P < 0.05).
The precise reason for elevated levels of RBP4 in overweight PCOS women is unknown, but it appears that 17beta-estradiol may play a role in their regulation in adipose tissue.
多囊卵巢综合征（PCOS）与胰岛素抵抗和肥胖相关。近期研究表明，血清视黄醇结合蛋白4（RBP4）水平随肥胖而升高。目前，关于PCOS女性血清或脂肪组织中RBP4的相对表达情况尚无相关数据。
比较超重PCOS女性皮下和网膜（om）脂肪组织及皮下脂肪细胞中RBP4的mRNA表达与匹配的对照组；同时评估脂肪组织中的RBP4蛋白及血清RBP4水平。此外，我们研究了睾酮、17β-雌二醇、雄烯二酮和硫酸脱氢表雄酮对脂肪组织外植体中RBP4表达的影响。
采用实时RT-PCR和蛋白质免疫印迹法评估RBP4的相对mRNA和蛋白表达。同时进行生化检测。
与对照组相比，PCOS女性皮下（P < 0.05）和网膜（P < 0.01）脂肪组织以及分离的皮下脂肪细胞（P < 0.01）中RBP4 mRNA显著上调。除PCOS女性血清RBP4水平升高外（P < 0.05），PCOS女性皮下和网膜脂肪组织中RBP4蛋白水平也显著更高（分别为P < 0.05和P < 0.05）。此外，在人皮下和网膜脂肪组织外植体中，17β-雌二醇显著增加RBP4 mRNA表达、蛋白水平及向培养基中的分泌（P < 0.05）。
超重PCOS女性中RBP4水平升高的确切原因尚不清楚，但17β-雌二醇似乎在其脂肪组织调节中发挥作用。
