Aluminum maltolate induces primary rat astrocyte apoptosis via overactivation of the class III PI3K/Beclin 1-dependent autophagy signal

作者：Zeng Ke Wu; Fu Hong; Liu Geng Xin; Wang Xue Mei^*

来源：Toxicology in Vitro, 2012, 26(2): 215-220.

DOI：10.1016/j.tiv.2011.11.010

• Astrocyte
• Aluminum
• Autophagy
• Apoptosis

Aluminum-induced neuronal cell apoptosis has been implicated in various neurodegenerative disorders. However, whether autophagy, a vital lysosomal degradation pathway, is involved in this pathogenesis still remains unknown. Our present findings demonstrated that aluminum significantly increased rat astrocyte apoptosis and autophagy levels in a dose-dependent manner. Examination of the associated mechanisms revealed that aluminum at low levels (400 MM) did not increase apoptosis protein expressions (cleaved caspase-3 and cleaved PARP), but markedly up-regulated autophagy-related protein Beclin 1 expression. This indicates that the autophagy process occurs earlier than neuronal apoptosis. Moreover, aluminum at high levels (1600 MM) significantly induced autophagy-related protein (Beclin 1 and LC3II) and apoptosis-related protein expressions, showing that both autophagy and apoptosis processes are activated under high levels of aluminum exposure. We used 3-methyladenine, an inhibitor of class Ill phosphatidylinositol-3 kinase, to treat astrocytes and found that the apoptosis rate in the 3-MA/aluminum co-treated group was markedly down-regulated compared with aluminum alone-treated astrocytes. The apoptosis protein and autophagy-related protein expressions were also decreased. These observations showed that the mild autophagy process may precede apoptosis in low dose aluminum-insulted astrocytes, and high dose aluminum-induced serious autophagy may result in cell apoptosis via the Beclin 1-dependent autophagy signal pathway.

• 出版日期2012-3
• 单位北京大学