Abstract:

Objective  To explore the effect of hypoxia on the autophagy of PC12 cells. Methods  The hypoxia incubator was used to establish the hypoxic environment with oxygen concentration of 1% for treating cells of the experimental group, while cells of the control group were placed in the incubator with normal oxygen concentration. Firstly, cells of the experimental group were treated in hypoxic environment for 6, 12, and 24 h respectively. Expressions of autophagy-related proteins LC3 and Beclin1 were detected by Western blotting and changes of mRNA of LC3 were detected by RT-PCR. Changes of autophagosomes were observed by the transmission electron microscope. Secondly, after being treated by autophagy inhibitor 3-MA, the viability of cells was detected by MTT, the activity of caspase-3 was detected by caspase-3 activity assay kit, and the expression of cleaved caspase-3 was detected by Western blotting. Results  ①With the increase of time of exposure to hypoxic environment, expressions of autophagy-related proteins LC3 and Beclin1 and mRNA level of LC3 of PC12 cells increased, reached peaks during 12-24 h, and decreased afterward. ②The autophagy inhibitor 3-MA further decreased the viability of cells treated by hypoxic environment and increased the activity of caspase-3 and expression of active caspase-3. Conclusion  Hypoxia activates the autophagy of PC12 cells and may play a protective role by inhibiting the apoptosis.

Key words: PC12 cells, hypoxia, autophagy