Binding and internalization of leptin by porcine choroid plexus cells in culture

Leptin is an adipocyte derived hormone with profound behavioural and metabolic effects exerted by both central and peripheral sites of action. One of its targets in the central nervous system appears to be the epithelial cells of the choroid plexus where leptin receptor (OB-R) expression is particularly high. The most abundant receptor subtype at this site is OB-Ra which is truncated at its intracellular part and has been suggested to serve functions such as leptin transport or clearance. The choroid plexus may thus be a site where receptor mediated exchange of leptin between cerebrospinal fluid and blood takes place. The study here shows that porcine plexus epithelia preserve their ability of OB-R expression when grown in culture. In addition, our experiments suggest that leptin is rapidly internalized upon binding to these cells supporting the view of an OB-R mediated transport of leptin across the choroid plexus.