p53/HIF-1α regulates neuronal aging and autophagy in spinal cord ischemia/reperfusion injury.

OBJECTION: Spinal cord injury (SCI)-induced hindlimb dysfunction affects the physical and mental health of patients. There is growing evidence suggesting that the recovery capacity of elderly SCI patients is poorer than that of young individuals. However, the specific molecular mechanisms remain unclear.

METHODS

RNA expression profiles of SCI samples were collected from the GEO database, and key genes involved in the progression of SCI were identified by the limma package in R software. A diagnostic model based on SCIDEG was constructed using LASSO regression analysis. Subsequently, correlation analysis was conducted to identify biological pathways influenced by the key genes. Furthermore, SCI animal models were established in different age groups to examine the expression of relevant genes and verify the molecular mechanism of p53/HIF-1α axis.

RESULTS

We initially identified 34 ischemia-hypoxia-related genes potentially involved in the progression of SCI. Subsequently, we constructed a diagnostic model based on SCIDEGs using LASSO regression analysis. This model highlighted 9 key genes (TP53, SFTPA1, MASP2, KRT14, IL9, HIF1A, HGFAC, FUT7, and ALPP), which demonstrated high diagnostic accuracy in both the training set (AUC=1) and the validation set (AUC=0.855). Further cross-analysis with ischemia-reperfusion-related datasets confirmed the involvement of HIF1A and TP53. We also observed significant enrichment of HIF1A in organoids composed of mature neurons, which induced neuronal damage. In subsequent spinal cord injury animal models of different age groups, we found that HIF-1α expression was downregulated in the spinal cord tissues of elderly animals. Additionally, we discovered that TP53 activation induces cellular senescence in aging neurons and suppresses HIF-1α expression and autophagy levels within these cells.

CONCLUSION

In summary, our study suggests that the p53/HIF-1α signaling pathway plays a critical role in regulating neuronal aging and autophagy in the pathogenesis of SCI. Importantly, HIF-1α may represent a promising therapeutic target for SCI treatment.