Expressions of VEGF-A and VEGFR-2 in placentae from GDM pregnancies.

BACKGROUND: Gestational diabetes mellitus (GDM) is one of the most common medical complications of pregnancy, and has important health implications for mother and child. Changes in the fetoplacental vessels may predict those in the vasculature of the developing fetus, as these have been implicated in the pathogenesis of human GDM. This study aimed to determine the differences in the localization and expression level of VEGFA and VEGFR2 between placentas of women with GDM and placentas of normal pregnancies, which is the first step in elucidating the possible roles of VEGFA and VEGFR2 in the altered uteroplacental function resulting from maternal hyperglycaemia and ultimately in the manifestation of GDM. METHODS: The expressions of VEGFA and VEGFR2 mRNA and protein in 20 samples from each group were analyzed by real-time PCR, immunohistochemistry and Western blot. The placental blood barrier and angiogenesis were observed by the transmission electron microscopy (TEM) in10 GDM samples and ten controls. RESULTS: The expression levels of VEGFA and VEGFR2 mRNA and protein were significantly decreased in the GDM group (P < 0.05 or 0.01). Immunohistochemical analysis showed the reduced expression of VEGFA and VEGFR2 protein in GDM-affected placental tissues, and the degenerative alterations of the terminal villi vascular. CONCLUSION: The expressions of VEGFA and VEGFR-2 mRNAs and protein were reduced in GDM-affected placental tissues, suggesting that maternal GDM affects the pathophysiological function of placentas.

Ultrastructure of Placenta of Gravidas with Gestational Diabetes Mellitus.

Objectives. Gestational diabetes mellitus (GDM) leads to an abnormal placental environment which may cause some structural alterations of placenta and affect placental development and function. In this study, the ultrastructural appearances of term placentas from women with GDM and normal pregnancy were meticulously compared. Materials and Methods. The placenta tissues of term birth from 10 women with GDM and 10 women with normal pregnancy were applied with the signed informed consent. The morphology of fetomaternal interface of placenta was examined using light microscopy (LM) and transmission electron microscopy (TEM). Results. On LM, the following morphological changes in villous tissues were found in the GDM placentas when compared with the control placentas: edematous stroma, apparent increase in the number of syncytial knots, and perivillous fibrin deposition. On TEM, the distinct ultrastructural alterations indicating the degeneration of terminal villi were found in the GDM placentas as follows: thickening of the basal membrane (BM) of vasculosyncytial membrane (VSM) and the VSM itself, significantly fewer or even absent syncytiotrophoblastic microvilli, swollen or completely destroyed mitochondria and endoplasmic reticulum, and syncytiotrophoblasts with multiple vacuoles. Conclusion. Ultrastructural differences exist between GDM and control placentas. The differences of placenta ultrastructure are likely responsible for the impairment of placental barrier and function in GDM.