| Summary: | 碩士 === 中國醫藥大學 === 神經科學與認知科學研究所碩士班 === 101 === Astrocytes do not only maintain extra-neuronal homeostasis, but also play an active role in modulating synaptic transmission by releasing gliotransmitters. Palmitic acid (PA) is a saturated fatty acid which, when being excessive, is a significant risk factor for development of metabolic syndromes or stroke. Activation of astrocytes by PA has been shown to cause neuronal inflammation and demyelination. However, direct damage by PA to astrocytes is relatively unexplored. The aim of this study was to identify the mechanism(s) of PA-induced cytotoxicity in rat cortical astrocytes. Exposure of astrocytes to PA (100 μM) for 24 h resulted in approximately 50 % cell death. Cell death was apoptotic (as revealed by TUNEL assay) and unrelated to endoplasmic reticulum (ER) stress and cytosolic Ca2+ elevation. Exposure of astrocytes to PA for 30 min to 5 h was associated with significant mitochondria membrane potential (MMP) collapse and reactive oxygen species (ROS) production. Co-treatment of astrocytes with (+)-catechin (300 μM), an anti-oxidant found abundantly in green tea, significantly prevented PA-induced MMP collapse, ROS production and cell death. Our results suggest that PA-induced cytotoxicity in astrocytes may involve MMP collapse and ROS production, which can be prevented by (+)-catechin.
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