Department of Obstetrics and Gynecology, Shengjing Hospital Affi liated to China Medical University, 36 Sanhao Street, Heping District, Shenyang, China.
J Perinat Med. 2011 Nov 19;40(2):129-35. doi: 10.1515/JPM.2011.128.
To compare the expression of sex hormone binding globulin (SHBG) in normal placental tissues with placental tissues from patients with gestational diabetes mellitus (GDM) and to deduce the mechanism affecting placental SHBG in GDM.
We detected SHBG localization and measured SHBG mRNA and protein using immunohistochemistry, reverse-transcription polymerase chain reaction, and Western blotting, respectively, in normal and GDM placental tissues. The distribution of SHBG in placental cells was examined using immune electron microscopy.
Compared to controls, placental tissues from patients in the GDM group displayed disordered cell surface microvilli that were decreased in quantity, swollen, and had narrowed and broken gap junctions. Intracellular abnormalities included expanded rough endoplasmic reticula, swollen mitochondria, and irregular nuclear morphologies with non-uniform chromatin. SHBG localized primarily to trophoblast cell membranes and cytoplasm. SHBG was strongly expressed on the microvilli side and weakly expressed on the basement membrane with uneven staining. SHBG also was expressed in villous stromal cells and vascular endothelial cells. Compared to the controls, placental tissues from the GDM group displayed significantly decreased immunostaining rates for SHBG, as well as significantly lower levels of SHBG mRNA and protein expression (P<0.05).
SHBG was detected in placental trophoblast cells from patients with GDM, and the synthesis and secretion of SHBG were reduced when trophoblast cells were irregular. A decrease in SHBG could affect placental function or aggravate GDM. Our results suggest that placental SHBG plays an important role in the pathogenesis of GDM.
比较正常胎盘组织和妊娠期糖尿病（GDM）胎盘组织中性激素结合球蛋白（SHBG）的表达，推断影响 GDM 胎盘 SHBG 的机制。
采用免疫组织化学、逆转录聚合酶链反应和 Western blot 法分别检测正常和 GDM 胎盘组织中 SHBG 的定位及 SHBG mRNA 和蛋白，并用免疫电镜观察 SHBG 在胎盘细胞中的分布。
与对照组相比，GDM 组胎盘组织的细胞表面微绒毛排列紊乱，数量减少，肿胀，细胞间隙变窄、断裂。细胞内异常包括扩张的粗面内质网、肿胀的线粒体和不规则的核形态，染色质不均匀。SHBG 主要定位于滋养层细胞膜和细胞质。SHBG 在微绒毛侧强表达，在基膜弱表达，染色不均匀。SHBG 还在绒毛间质细胞和血管内皮细胞中表达。与对照组相比，GDM 组胎盘组织中 SHBG 的免疫染色率显著降低，SHBG mRNA 和蛋白表达水平也显著降低（P<0.05）。
在 GDM 患者的胎盘滋养层细胞中检测到 SHBG，当滋养层细胞不规则时，SHBG 的合成和分泌减少。SHBG 的减少可能会影响胎盘功能或加重 GDM。我们的研究结果表明，胎盘 SHBG 在 GDM 的发病机制中起重要作用。
