Objective To investigate the changes of key factors such as placental villi and lymph vessels in chronic venous disease (CVD) during pregnancy. Methods According to the CEAP classification criteria, tissues of CVD patients were collected, and was divided into control group and CVD group. Real-time quantitative PCR was used to detect
mRNA level of CD31, D2-4, fms-related
tyrosine kinase 1 (FLT-1), placental
growth factor (PlGF) and
hypoxia-inducible factor-1 (HIF-1α) in placental tissues. Immohistochemical staining was performed to measure the expression level of CD31, D2-40, FLT-1, PlGF, HIF-1α,
B-cell lymphoma 2 (Bcl2), Bcl2-related X
protein (BAX),
caspase 3 and
caspase-9. The change in average number of syncytiotrophoblast cell nodes in placental villi was observed by optical microscope and transmission electron microscope.
Periodic acid Schiff (PAS) staining was used to detect the PAS-positive substances in placental villi. Results Compared with the control group, the average numbers of placenta villi, syncytiotrophoblast cell nodes, syncytiotrophoblast cell nodes/villi and the connection bridges between villi of the average syncytrotrophoblast cells increased significantly in the CVD group, while the average number of fibrinoid
necrosis showed no significant changes. The
mRNA levels of CD31, D2-40, FLT-1, PlGF, and HIF-1α in the CVD group also increased significantly, and the proportion of villi cells positive of BAX,
caspase-3 and
caspase-9 rose significantly, while that of villi cells positive positive of Bcl2 showed no obvious change. CVD group also reported a marked increase in the number of blood vessels positive of CD31, D2-40, FLT-1 and PlGF. The expression level of HIF-1α in syncytiotrophoblast cells, cytotrophoblast cells and fetal capillary villi increased significantly in the CVD group. The percentage of placenta with PAS positive substances observed an increase in the villi, in comparison to the control group. Conclusion The production of blood vessels and lymph vessels increased in the placental villi of patients with CVD, coupled with an accelerated apoptosis of villi cells. Meanwhile, CVD patients show an impaired function of placental villi and obstructed gas exchange between mother and infant.