[Inhibitory effect of autophagy on apoptosis of rat cerebral cortical neurons after oxygen-glucose deprivation and reoxygenation (OGD/R)].

Objective To observe the effect of autophagy on apoptosis of cerebral cortical neurons after oxygen-glucose deprivation and reoxygenation (OGD/R). Methods Eighteen newborn SD rats born within 24 hours were selected. The cortical neurons were extracted by mechanical trypsin digestion and cultured for 7 days. The OGD/R model was established. The rats were randomly divided into 3 groups: control group, OGD/R group, and OGD/R combined with Bafilomycin A1(BafA1) group. Cell viability was detected by CCK-8 assay and lactate dehydrogenase (LDH) assay, and apoptosis was detected by flow cytometry combined with fluorescein isothiocyanate labeled annexin V/propidium iodide (annexin V-FITC/PI) double labeling. The mRNA expressions of microtubule associated protein 1 light chain 3 (LC3), P62 and cystatin 3 (caspase-3) were detected by reverse transcription PCR, and the protein expressions of LC3, P62 and caspase-3 were detected by Western blot analysis. The autophagy fluorescence intensity of neurons infected with red fluorescent protein-green fluorescent protein-LC3 (RFP-GFP-LC3) adenovirus was measured, and the ultrastructural changes of autophagosomes were observed by transmission electron microscopy. Results Compared with the control group, the activity of nerve cells in OGD/R group decreased significantly while the release level of LDH increased significantly and the apoptosis increased significantly; It was also detected the increased mRNA and protein expressions of LC3, P62 and caspase-3, increased fluorescence intensity of RFP, increased autophagosomes and more gathered autophagy lysosomes. The fluorescence intensity of RFP decreased significantly after adding late autophagy inhibitor BafA1. Conclusion OGD/R induces autophagy and apoptosis of neurons, and aggravates neuronal injury and apoptosis after inhibition of autophagy.