Ionic transport in a human trophoblast cell line (BeWo) and in human placenta

MARINO GI.; DEL MÓNACO SM.; ASSEF YA.; KOTSIAS BA.

Buzios, Río de Janeiro, Brasil

Congreso; VII Iberoamerican Congress of Biophysics; 2009

Iberoamerican Congress of Biophysics

Human syncytiotrophoblast (STh) in placenta regulates the transport of nutrients between mother and fetus. The CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) chloride channel was described in STh and we demonstrated that in BeWo cells, a human trophoblast cell line, the Epithelial Sodium Channel (ENaC) is present. The aim of this work is to continue studying chloride and sodium channels in BeWo cells and human placenta using electrophysiological and molecular biology techniques, and cellular migration assays. We identified in BeWo cells a linear Cl- channel, comparable with CFTR (g= 14.85 ± 0.92 pS, n=3) and a Cl- channel with outward rectifying properties similar to ORCC (g outward= 55 ± 4.43 pS, g inward= 20.7 ± 6.54 pS, n=7) by patch clamp. Besides, we detected the CFTR by RT-PCR and Western blot (~160 kDa). The same molecular biology studies evidenced that cells cultivated with aldosterone express alpha-ENaC, beta and gamma-ENaC mRNA and proteins, and we confirmed the expression of the channel in human placenta by RT- PCR, Western blot and immunohistochemistry. Wound healing studies in BeWo cells showed that there was a significant increase in cell migration in aldosterone treated cells at 6 h, effect that could be prevented adding the ENaC blocker amiloride. No changes in cell proliferation (MTT assay) were detected in the culture in any treatment. The ENaC channel may participate in the migration activity of BeWo cells. We believe that the data presented in this work could help for future studies on the physiology of the placenta and the proteins involved on ion transport in this tissue.