Study on Abnormal Angiogenesis in Moyamoya Disease via Mitochondrial D-Loop Methylation.

BACKGROUND: Mitochondrial D-loop methylation leads to abnormal cerebral angiogenesis. This study examines its role in vascular phenotypes of moyamoya disease (MMD). METHOD: Blood samples from 96 intracranial artery stenosis/occlusion (ICASO) patients (35 MMD, 61 non-MMD) and healthy controls underwent methylation analysis. D-loop methylation levels were analyzed using chi-square, T-test, and Wilcoxon tests. Propensity score matching (PSM) adjusted for age and gender disparities. Combine clinical information with methylation data to build a diagnostic model. Further studies included the methylation levels in MMD patients carrying the RNF213 p.R4810K mutation and the methylation levels and possible mechanisms of human brain microvascular endothelial cells (hCMEC/D3) with RNF213 knockdown. RESULTS: Healthy controls showed higher D-loop methylation than MMD (p < 0.05). Post-PSM, non-MMD ICASO patients showed higher D-loop methylation than MMD (p < 0.05). The AUC of the prediction model was 0.891 (95% CI, 0.821-0.961) after combining clinical information with methylation data. MMD patients with the RNF213 mutation exhibited reduced methylation at most sites, though not statistically significant (p > 0.05). RNF213 knockout in hCMEC/D3 enhanced proliferation, migration, and tube formation, while reducing apoptosis and DNMT1 expression, leading to decreased D-loop methylation and ROS level, increased ATP production and mitochondrial membrane potential. CONCLUSION: There are differences in the methylation levels in the mitochondrial D-loop region between MMD and non-MMD ICASO. The methylation-metabolism-angiogenesis axis may represent a promising research direction for elucidating MMD pathogenesis.