Unraveling Ammonia-Induced Brain Endothelial Senescence: Role of miRNA-183-5p

<b><i>Aims:</i></b> Hyperammonemia, defined by elevated ammonia levels, may co-occur in various neurological disorders, but its effects on cerebrovascularity are not fully understood. This study aimed to investigate how hyperammonemia affects brain endothelial cells senescence and selected within <i>in silico</i> analysis micro RNA-183-5p in this process. <b><i>Results:</i></b> Reduction in cerebrovascular density in hyperammonemia-induced rats, similar to that seen in 12-month-old rats, using von Willebrand factor staining, was observed. MicroRNA (miRNA) profile analysis of the brain cortex and plasma identified miRNA-183-5p contributing to endothelial senescence. <i>In vitro</i> studies of ammonia-treated rat brain endothelial cell line 4 showed senescent features, including increased β-galactosidase activity, higher mRNA levels and fluorescence intensity of p16 and p21, and altered senescence-associated secretory phenotype. Additionally, the transfection of miRNA-183-5p mimic induced similar senescent characteristics in endothelial cells, whereas miRNA-183-5p mimic inhibition reversed some effects. <b><i>Innovation:</i></b> This study is the first to link hyperammonemia-induced cerebrovascular dysfunction with miRNA-183-5p, highlighting its role in promoting endothelial senescence. The findings suggest that miRNA-183-5p could be a target for therapeutic interventions, preventing ammonia-induced brain endothelial dysfunction. <b><i>Conclusion:</i></b> Hyperammonemia promotes brain endothelial cells senescence through miRNA-183-5p, reducing cerebrovascular density. This may contribute to cerebral dysfunction seen in hyperammonemia-associated neurological disorders. Targeting miRNA-183-5p could offer a novel therapeutic strategy to mitigate endothelial dysfunction and preserve brain health in hyperammonemia. <i>Antioxid. Redox Signal.</i> 43, 254-271.