ABSTRACT
<p><b>OBJECTIVE</b>To investigate the regulation of different hypoxia on cell survival and autophagy.</p><p><b>METHODS</b>PC12 cells were treated with different hypoxia. The cell survival was measured by MTT assay, expressions of LC3 and p62 were marked for autophagy detected by Western Blot, and the level of reactive oxygen species (ROS) was analyzed by flow cytometry.</p><p><b>RESULTS</b>The cell viability was different under different hypoxia: moderate hypoxia promoted cell viability, and severe hypoxia caused a decrease in cell viability; autophagy marker molecules, p62 and LC3-II expressions were different: moderate hypoxia increased p62 and LC3-II expressions, in contrast, severe hypoxia led to the decrease of p62 and LC3-II expressions; compared to normoxia, moderate hypoxia did not change the levels of ROS, while severe hypoxia increased the levels; 3-MA, the inhibitor of autophagy, elevated the levels of ROS in the three oxygen concentrations, additionally, the increased amplitudes in the moderate and severe hypoxia groups were higher than that in the normoxia group.</p><p><b>CONCLUSION</b>Moderate hypoxia promotes cell survival, severe hypoxia causes the cell death, and the autophagy activity may mediate the effects of different hypoxia.</p>