Abstract Body: Dysregulation of microRNA (miRNA) is associated with hypertension and other diseases. We previously observed direct interaction of miR-410-3p with AT₁R and sex-dependent downregulation of miR-410-3p in the hypothalamus of a mouse cardiometabolic disease (CMD) model, suggesting a possible involvement in the development of CMD through modulation of the renin-angiotensin system. To further investigate the role of hypothalamic miR-410-3p expression as a therapeutic target for hypertension, acute Ang-II injection and chronic infusion experiments were performed. In acute experiments, C57BL/6J mice (males and females) were injected with Lenti-miR-410-3p or a control virus (icv, 2 µl, n=5-6). After 3 weeks, mice were anesthetized and a catheter was inserted to the carotid artery for blood pressure (BP) monitoring, followed by a bolus icv injection of Ang-II (200 ng/200 nl). Changes in systolic BP (ΔSBP) were recorded. In chronic experiments, mice were fed with a high calorie diet for 2 months before icv virus injection (2 µl). Telemetry probes (DSI) were implanted for conscious BP monitoring. Three weeks following virus injection, all mice were infused with Ang-II using osmotic minipumps (sc, 600 ng/kg/min, 14 days) to induce CMD. BP was recorded weekly and 24 h average of mean arterial pressure (MAP) was calculated. Acute Ang-II injection-induced pressor responses were similar in males (ΔSBP; 22.2±4.7 mmHg) and females (20.6±6.5 mmHg) transfected with the control virus. In lenti-miR-410-3p transfected mice, the pressor responses were blunted in both males (6.7±4.8 mmHg, P<0.001 vs. control) and females (10.9±4.7 mmHg, P<0.05 vs. control), with a greater reduction observed in males (69.8% vs. 47%). In the HCD model, baseline MAP was not different between male control and Lenti-miR-410, or female control and Lenti-miR-410 group. Following Ang-II infusion, MAP was increased in both sexes treated with control virus. Interestingly, this increase was blunted by Lenti-miR-410-3p expression in males (137.3 ± 9.4 vs. 160.7 ± 4.3 mmHg, P=0.05) but not in females (140.4±4.6 vs. 140.5 ± 4.2 mmHg). These data are aligned with our previous findings that male mice had higher expression of hypothalamic AT₁R than in females in CMD. In summary, miR-410-3p inhibits both acute and chronic Ang-II induced increases in BP in a sex-dependent manner, with more profound effects in males. miR-410-3p could be a new strategy for the treatment of hypertension in CMD.