Background <p>Endothelial-to-mesenchymal transition (EndMT) in endothelial dysfunction exacerbates hypertension. However, the regulatory mechanisms underlying EndMT in hypertension are yet to be elucidated.</p> Methods <p>The N-acetyltransferase 10 (NAT10) and N4-acetylcytidine (ac4C) levels were determined in hypertensive mice, spontaneously hypertensive rats (SHRs), and angiotensin II (Ang II)-treated human umbilical vein endothelial cells (HUVECs). Biological functional assays were performed with lentiviral vectors to induce the overexpression or knockdown of NAT10 in vivo and in vitro. The detailed mechanisms underlying the role of ac4C-mediated posttranscriptional regulation in hypertension were investigated by combining ac4C-RIP-seq with RNA-seq, RIP-qRCR, mRNA stability, and dual-luciferase assays. Mitochondrial biogenesis and function were assessed via reactive oxygen species (ROS) and mitochondrial ROS (mtROS) staining; estimation of ATP levels, the mitochondrial membrane potential (MMP), and the mtDNA content; and evaluation of mitochondrial respiratory chain complex activities.</p> Results <p>The results revealed that NAT10 and ac4C levels are higher in the hypertensive mice descending thoracic aorta tissues, SHRs descending thoracic aorta samples, and Ang II-treated HUVECs compared to the control groups. NAT10 overexpression inhibits EndMT in hypertension, which is partly due to the inhibition of endothelial dysfunction, whereas NAT10 inhibition has the opposite effect. Mechanistically, NAT10 inhibited endothelial dysfunction in hypertension through increased AdipoR1 mRNA ac4C acetylation. Moreover, NAT10 induced AdipoR1 expression, leading to increased mitochondrial biogenesis and function in Ang II-treated ECs via p38 MAPK/PGC-1α signaling.</p> Conclusions <p>The current data highlighted the molecular mechanisms of NAT10-induced ac4C acetylation and implied that the NAT10-AdipoR1 axis might be the therapeutic target to inhibit endothelial dysfunction and EndMT in hypertension.</p>