Biological function of EPHB4 in the aging process of vascular endothelial cells: mtDNA molecular mechanism and MAPK/PGC-1/TFAM signaling pathway.

Previous studies have shown that EPHB4 is also involved in regulating the proliferation, migration, and apoptosis of endothelial cells. In this study, we found a close relationship between EPHB4 and aging. Therefore, in-depth research on the relationship between EPHB4 and aging can help reveal the molecular mechanisms of aging and provide new ideas and methods for developing anti-aging drugs and treating vascular aging-related diseases. In addition, in our current study, we found a close relationship between EPHB4, cellular senescence, and CM-AVM. The MAPK/PGC-1/TFAM signaling axis mediated by EPHB4 may also be involved in the process of CM-AVM, laying a solid foundation for future in-depth studies on the relationship between EPHB4 and CM-AVM. Our findings revealed a decrease in mitochondrial membrane potential associated with EPHB4 deficiency, suggesting that EPHB4 loss may contribute to mitochondrial dysfunction. Additionally, EPHB4 deficiency led to an elevation in mitochondrial ROS levels, which was confirmed using mitochondrial-specific fluorescent probes. Furthermore, EPHB4 deficiency resulted in down-regulated expression of NRF1 and SOD2, which could be a significant contributor to mitochondrial oxidative stress. To validate this hypothesis, we conducted rescue experiments by restoring PGC-1 expression. The results showed a partial recovery of mitochondrial membrane potential and a reduction in cell senescence. These findings suggest that EPHB4 regulates mitochondrial functional integrity through the MAPK/PGC-1/TFAM signaling axis.