Reduced expression of follicle stimulating hormone receptor mRNA and protein in pregnancies complicated by pre‑eclampsia.

Expression and function of the follicle‑stimulating hormone receptor (FSHR) are traditionally thought to be limited to the ovary in females. However, recent studies have indicated that the FSHR is also expressed in endothelial cells of the placental vasculature, and that the haploinsufficiency of the feto‑placental FSHR impaired the growth of the mouse placenta. The aim of the current study was to investigate the placental expression of FSH and FSHR in pregnancies complicated by pre‑eclampsia. Placental tissue samples were collected from 20 pregnancies with pre‑eclampsia and 25 normal pregnancies. Placental FSH and FSHR mRNA levels were measured by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR), while FSH, FSHR and CD31 protein expression were examined by immunohistochemistry. Additionally, levels of serum FSH were measured by chemical luminescence immunity assay. The results demonstrated that no significant difference was observed in serum FSH levels and expression levels of placental FSH mRNA and protein between normal pregnancy and pre‑eclampsia. However, RT‑qPCR results indicated that the expression level of FSHR mRNA in pre‑eclamptic placental samples was significantly lower than normal pregnancies. Immunostaining results from normal pregnant samples indicated that the FSHR protein was strongly expressed in the endothelial cells of blood vessels in the chorionic villi, moderately expressed in stromal cells of the villus, but not expressed in trophoblast cells of the term placenta. The staining intensity of FSHR‑positive area was significantly lower in the placental villi of pre‑eclampsia, when compared with the normal control group. In conclusion, expression levels of placental FSHR mRNA and protein are significantly reduced in pregnancies complicated with pre‑eclampsia in the present study. Further studies may investigate whether FSHR could be used as a biomarker for the prediction of pre‑eclampsia.