Brain endothelial PRMT5-ANGPTL4 axis regulates cerebellar inhibitory synaptogenesis and motor coordination

Brain vasculature is essential for central nervous system function, but its specific roles in synaptic development and motor function regulation are poorly understood. In this study, we identify a cerebrovascular signaling axis wherein endothelial PRMT5 critically regulates inhibitory synaptogenesis and motor coordination. Cerebrovascular-specific deletion of Prmt5 gene leads to excessive inhibitory synaptic input onto Purkinje cells and progressive motor deficits in mice. Mechanistically, PRMT5 deficiency epigenetically upregulates the expression of the secreted factor ANGPTL4 through reduced symmetric dimethylation of H3R8 and H4R3, along with increased H3K9 acetylation at the Angptl4 promoter, thereby driving excessive inhibitory synaptogenesis onto Purkinje cells. Importantly, Angptl4 deletion in brain endothelium normalizes inhibitory synaptic input onto Purkinje cells and restores motor coordination in PRMT5-deficient mice. Together, these findings define the endothelial PRMT5-ANGPTL4 axis as a key regulator of cerebellar inhibitory circuitry and motor function, highlighting cerebrovascular mechanisms as potential therapeutic targets for motor coordination disorders. Teaser Cerebrovascular PRMT5 prevents excessive inhibitory synaptogenesis via epigenetic repression of Angptl4.