The Effect And Underlying Mechanism Of Resveratrol- Mediated Cellular Calcium And Glucose Utilization In Rat Cortical Neurons

Partâ… The effect and mechanism of RSV on [Ca²⁺]_i in rat cortical neuronsBackground: Resveratrol (RSV), a polyphenol widely found in red wine, peanuts and pomegranate, has attracted tremendous attention over the past couple of decades. Many reports have highlighted its benefits including antioxidation, regulation of energy metabolism, neuroprotection and anti-aging effect .RSV can cause many kinds of nerve cells to increase intracellular calcium. However, the mechanism of the cellular responses to RSV, particularly in cortical neurons is unclear, In this study, we set out to explore the precise mechanism underlying RSV-mediated calcium signaling in cortical neuronsMethods: The effect and the mechanism of RSV on [Ca²⁺]_i in cultured rat prefrontal cortical neurons were investigated by calcium imaging.Results: RSV increased [Ca²⁺]_i in a dose-dependent manner in cortical neurons. The increase of [Ca²⁺]_i induced by 5μM, 10μM, 50μM and 100μM RSV is 42.30±0.53%, 138.30±1.19 %, 200.88±8.19 % and 365.18±5.48%, respectively. The increase in [Ca²⁺]_i induced by RSV was partly blocked by ICI182780 (10μM, a inhibitor of estrogen receptor),L-NAME (100μM, a inhibitor of NOS), ODQ (20μM, a inhibitor of GC) and KT5823 (10μM, a inhibitor of PKG). The effect of RSV on [Ca²⁺]_i was also partly blocked by SQ22536(100μM, a inhibitor of AC)and H89 (20μM, a inhibitor of PKA).Conclusion: RSV increases [Ca²⁺]_i in a dose-dependent manner by mobilization of intracellular calcium stores .Activation of ER-NOS-GC-PKG and AC-PKA signal pathway contribute to the RSV-induced [Ca²⁺]_i rise. Elevation of Sirt1 and AMPK are not involved in RSV-induced increase in [Ca²⁺]_i Partâ…¡The effect and the mechanism of RSV-mediated neuronal glucose uptakeBackground: Recent research implicates an important role of Ca²⁺ in cellular energy utilization, especially glucose uptake. In this study, we set out to explore the precise mechanism underlying RSV-mediated glucose uptake in cortical neurons.Methods:First, the effect of RSV on activation of AMPK signal was investigated by western blotting. Second, cortical neurons were pretreated with 300μM NBDG (a fluorescein derivative of D-glucose). After application BAPTA-AM (an intracellular calcium chelator), Compound C (a inhibitor of AMPK) and BFA (a inhibitor of exocytosis), the effect of RSV on the density of fluorescence was observed by Two-photon Fluorescence Microscopy. Last, the effect and mechanism of RSV on exocytosis were investigated by pretreatment with FM1-43 (a dye monitoring exocytosis)Results: RSV rapidly activated AMPK and increased exocytosis in a calcium dependent manner. The effects of RSV (100μM) increased the density of fluorescence produced by NBDG were eliminated via using BAPTA-AM (10μM), Compound C (100μM) and BFA (100μM).Conclusion: Calcium-dependent exocytosis and calcium-dependent activation of AMPK are essential for RSV mediated reinforcement of neuronal glucose uptake. But, RSV produces an exocytosis-enhancing effect without AMPK activation.