Expression of nephrin in the human placenta and fetal membranes.

Nephrin is the signature molecule in the podocyte of the glomerulus that forms the renal slit diaphragm, the main functional unit of the glomerulus. The present study focused on the expression of nephrin in the human placenta, which may also have a role in filtration and the maintenance of homeostasis in the kidneys. A total of nine placentas from normal healthy pregnant females at full term were investigated. Reverse transcription-quantitative polymerase chain reaction, western blotting and immunofluorescence were performed. The expression of nephrin mRNA was relatively increased in the chorion compared with that in the villi and the amnion. The nephrin gene was detected in the villous cytotrophoblast cells and the endothelium of the intravillous vessels. It was also present in the chorionic and amniotic membranous lining, with its distribution being particularly dense in the amniocytes. The identification of nephrin in the human placenta, particularly at the maternal‑fetal interface, provides a novel insight into the molecular basis of the selective permeability of the placental barrier, which requires further elucidation.