Ferulic acid promotes proliferation and angiogenesis of cerebral microvascular endothelial cells in Moyamoya disease via the SIRT1/HIF-1α/VEGF-A axis

BACKGROUND: Moyamoya disease (MMD) is characterized by progressive stenosis of the intracranial internal carotid arteries, resulting in chronic cerebral hypoperfusion and impaired angiogenesis. Oxidative stress, mitochondrial dysfunction, and endothelial apoptosis are recognized contributors to microvascular injury in ischemic MMD. Ferulic acid (FA), a natural phenolic compound with potent antioxidant and cytoprotective properties, has shown therapeutic potential in ischemic cerebrovascular injury. However, its role in restoring endothelial function and promoting angiogenesis in the context of MMD remains unclear. This study investigated whether FA protects brain microvascular endothelial cells (Bend.3) against oxygen-glucose deprivation (OGD)-induced injury and examined the involvement of the SIRT1/HIF-1α/VEGF-A signaling axis. METHODS: OGD was applied to mouse Bend.3 to mimic the hypoxic and ischemic microenvironment of MMD. The effects of FA on cell proliferation, migration, tube formation, and apoptosis were evaluated using CCK-8, scratch assay, Transwell, and Matrigel tube formation. Oxidative stress and mitochondrial function were assessed via ROS, MDA and JC-1assays. qPCR and western blotting were used to examine the expression of SIRT1, HIF-1α, VEGF-A, eNOS, and angiogenesis-related markers. The involvement of SIRT1 signaling was validated through siRNA-mediated SIRT1 silencing and SIRT1 inhibitor treatment. RESULTS: OGD induced significant apoptosis in Bend.3 cells, which was accompanied by the accumulation of reactive oxygen species (ROS), depolarization of the mitochondrial membrane, and a reduction in angiogenesis-related capacity. Conversely, treatment with ferulic acid (FA) enhanced cell viability, improved migration and tube formation, and mitigated apoptotic injury. Furthermore, FA decreased OGD-induced oxidative stress and partially preserved the mitochondrial membrane potential. At the signaling level, FA was associated with an increase in SIRT1 expression and elevated levels of HIF-1α protein, along with an upregulation of downstream angiogenesis-related mediators, including VEGF-A and eNOS. Notably, the knockdown of SIRT1 diminished several FA-associated protective and pro-angiogenic phenotypes and reduced the corresponding HIF-1α/VEGF-A responses under OGD conditions, thereby supporting a SIRT1-dependent mechanism in FA-mediated endothelial effects in this in vitro model. CONCLUSION: FA mitigated OGD-induced oxidative and mitochondrial injury in Bend.3 cells and promoted angiogenesis-related responses through activation of the SIRT1/HIF-1α/VEGF-A axis. These data support a SIRT1-dependent endothelial protective mechanism and provide a rationale for future studies evaluating FA in neurovascular-unit systems and in vivo models relevant to Moyamoya disease.