LAUSR

ABSTRACT Mild hypothermia has been proven to be useful to treat brain ischemia/reperfusion injury. However, the underlying mechanisms have not yet been fully elucidated. The present study was undertaken to determine whether mild hypothermia protects hippocampal neurons against oxygen‐glucose deprivation/reperfusion(OGD/R)‐induced injury via improving lysosomal function and autophagic flux. The results showed that OGD/R induced the occurrence of autophagy, while the acidic environment inside the lysosomes was altered. The autophagic flux assay with RFP‐GFP tf‐LC3 was impeded in hippocampal neurons after OGD/R. Mild hypothermia recovered the lysosomal acidic fluorescence and the lysosomal marker protein expression of LAMP2, which decreased after OGD/R.Furthermore, we found that mild hypothermia up‐regulated autophagic flux and promoted the fusion of autophagosomes and lysosomes in hippocampal neurons following OGD/R injury, but could be reversed by treatment with chloroquine, which acts as a lysosome inhibitor. We also found that mild hypothermia improved mitochondrial autophagy in hippocampal neurons following OGD/R injury. Finally,we found that chloroquine blocked the protective effects of mild hypothermia against OGD/R‐induced cell death and injury. Taken together, the present study indicates that mild hypothermia protects hippocampal neurons against OGD/R‐induced injury by improving lysosomal function and autophagic flux. HIGHLIGHTSOGD/R impaires lysosomes and impedes the autophagic flux in hippocampal neurons.Mild hypothermia rescues lysosomal function in neurons following OGD/R.Mild hypothermia up‐regulates the autophagic flux in neurons following OGD/R.Mild hypothermia improves mitochondrial autophagy in neurons following OGD/R.Chloroquine blocks the protective effects of mild hypothermia against OGD/R injury.