The journal of physiological sciences : JPS

Expression of the TRPM6 in mouse placental trophoblasts; potential role in maternal-fetal calcium transport.

PMID 27043350


The placenta is required to transport calcium (Ca(2+)) from mother to fetus during fetal bone mineralization. In an attempt to clarify the molecular basis of Ca(2+) entry for this transport, we identified TRPM6 as a candidate for apical Ca(2+) entry pathway. TRPM6 mRNA increased during the last 4xa0days of pregnancy, coinciding with fetal bone mineralization in mice. TRPM6 mRNA and protein was localized in the trophoblasts in labyrinth where the maternal-fetal Ca(2+) transport occurs. In patch-clamp recordings, we observed TRPM6/TRPM7-like currents in mouse trophoblasts after starting fetal bone mineralization but not before mineralization. Plasma membrane Ca(2+) permeability was significantly increased in TRPM6/TRPM7 expressed HEK293 cells under physiological Mg(2+) and ATP concentration but not in TRPM6 or TRPM7 homomer-expressing cells. These results suggest that TRPM6 is functionally expressed in mouse placental trophoblasts, implicating in maternal-fetal Ca(2+) transport likely with TRPM7, which might enable to sustain fetal bone mineralization.