Effects of Leptin on Na+/Ca2+ Exchanger in PC12 Cells

Background/Aims: Alzheimer's disease (AD) is known to be related to alterations in neuronal intracellular calcium activity ([Ca2+](i)). The present study revealed the distinct role of leptin in Na+/Ca2+-exchanger activity. Methods: [Ca2+], was determined utilizing Fura-2 fluorescence. The activity of NCX was measured by removal of extracellular Na+ in the presence of external Ca2+. Na+/Ca2+-exchanger activity was further quantified from whole cell currents following removal of extracellular Na+.Na+/Ca2+-exchanger isoform NCX1 transcript levels and protein abundance were quantified by RT-PCR and Western blotting, respectively. Results: Exposure of PC12 cells to 30 mu M amyloid (A beta(42)) increased [Ca2+], an effect significantly blunted by 6 hours incubation with leptin before A beta(42) treatment. Moreover; leptin treatment significantly increased Na+/Ca2+-exchanger mediated Ca+ transport and current, NCX1 transcript level as well as NCX1 membrane protein abundance. Conclusion: We show that leptin blunts A beta(42)-evoked [Ca2+](i), increase by increasing expression and activity of Na+/Ca2+-exchanger NCX1. (C) 2016 The Author(s) Published by S. Karger AG, Basel