Role of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in autophagy activation following subarachnoid hemorrhage

Background: Early brain injury (EBI) refers to a severe brain injury that occurs within hours to days after sub-arachnoid hemorrhage (SAH). Neuronal damage in EBI is considered a key factor leading to poor prognosis. Currently, our understanding of the mechanisms of neuronal damage, such as neuronal autophagy, is still incomplete. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a key enzyme in metabolism and plays an important role in autophagy. Based on this, this study will further explore the regulation of autophagy by GAPDH after SAH, which may provide a new treatment strategy for improving the prognosis of SAH patients. Methods: The rat SAH model was established by endovascular puncturing, and the trend of autophagy in hip-pocampal neurons at different time points was discussed. Additionally, an in vitro SAH model was created using the oxygenated hemoglobin and hippocampal neuronal HT22 cell line. Through siRNA and overexpression adenovirus techniques, we further investigated the relationship between the key enzyme GAPDH and autophagy in the in vitro SAH model. Results: We observed significant neuronal damage in the hippocampus 24 h after SAH, and the proteomics showed significant enrichment of autophagy-related pathways at this time point. Further studies showed that the expression of LC3 and Beclin1 peaked at 24 h, and the nuclear translocation of GAPDH occurred simultaneously with SAH-induced neuronal autophagy. Our in vitro SAH model confirmed the role of GAPDH in regulating the level of autophagy in HT22 cells. Knockdown of GAPDH significantly reduced the level of autophagy, while overexpression of GAPDH increased the level of autophagy. Conclusion: This study shows the trend of autophagy in hippocampal neurons after SAH, and reveals the regu-latory role of GAPDH in SAH-induced autophagy. However, further studies are needed to reveal the exact mechanism of GAPDH in the nuclear translocation regulation of autophagy and validate in animal models.