Division of Reproductive Endocrinology and Fertility and Department of Obstetrics and Gynecology, Duke University Medical Center, Durham, North Carolina 27713, USA.
J Clin Endocrinol Metab. 2012 Sep;97(9):E1741-4. doi: 10.1210/jc.2012-2027. Epub 2012 Jun 28.
Trophoblast-derived human chorionic gonadotropin (hCG) promotes corpus luteum progesterone (P4) production, and wide ranges of serum P4 levels are noted in various pregnancy outcomes, despite similar hCG concentrations. There are five unique biologically active hCG variants in human pregnancy urine, and previous studies of P4 production in response to hCG have used only preparations containing all isoforms. Understanding exactly which hCG variant is primarily responsible for stimulating corpus luteum steroidogenesis may have great clinical and diagnostic implications, including in the setting of ectopic pregnancy.
Our objective was to delineate the role of the standard and hyperglycosylated (H)-hCG isoforms in stimulating P4 production by luteinized granulosa cells.
Cell culture, ELISA, and fluorometric-based protein assays were done at Duke University Medical Center.
Patients were anonymous oocyte donors.
Cultured luteinized granulosa cells were treated with 0.25, 0.5, and 1.0 ng/ml total hCG, which contains all isoforms, purified standard hCG (37.1 kDa), and purified H-hCG (42.8 kDa).
P4 produced per total cellular protein (nanograms per microgram) was measured via ELISA and fluorometric protein determination kits.
Both total hCG (P = 0.0003) and purified standard hCG (P < 0.0001) stimulated a dose-dependent increase in P4 production. Purified H-hCG did not change the P4 produced per total cellular protein response (P value not significant).
Standard hCG stimulated P4 production by cultured granulosa cells and likely supports corpus luteum function via interactions with the LH/hCG receptor. In contrast, H-hCG did not increase P4 production, which indicates a nonsteroidogenic role for this protein during early gestation.
滋养层衍生的人绒毛膜促性腺激素（hCG）促进黄体孕激素（P4）的产生，尽管 hCG 浓度相似，但在各种妊娠结局中，血清 P4 水平的范围很广。在人类妊娠尿液中有五种独特的具有生物活性的 hCG 变体，之前关于 hCG 对 P4 产生的研究仅使用包含所有同工型的制剂。确切了解哪种 hCG 变体主要负责刺激黄体类固醇生成可能具有重要的临床和诊断意义，包括在异位妊娠的情况下。
我们的目的是描述标准和高糖基化（H）-hCG 同工型在刺激黄体化颗粒细胞产生 P4 中的作用。
在杜克大学医学中心进行细胞培养、ELISA 和基于荧光的蛋白质测定。
患者为匿名捐卵者。
用 0.25、0.5 和 1.0ng/ml 总 hCG（包含所有同工型）、纯化标准 hCG（37.1kDa）和纯化 H-hCG（42.8kDa）处理培养的黄体化颗粒细胞。
通过 ELISA 和荧光蛋白测定试剂盒测量每总细胞蛋白产生的 P4（纳克/微克）。
总 hCG（P=0.0003）和纯化标准 hCG（P<0.0001）均刺激 P4 产生剂量依赖性增加。纯化 H-hCG 未改变每总细胞蛋白反应产生的 P4（P 值无统计学意义）。
标准 hCG 刺激培养的颗粒细胞产生 P4，并可能通过与 LH/hCG 受体的相互作用支持黄体功能。相比之下，H-hCG 并未增加 P4 的产生，这表明该蛋白在早期妊娠中具有非甾体生成作用。
