BACKGROUND: Small artery remodeling and endothelial dysfunction are hallmarks of hypertension. Evidence supports a likely causal association between cardiovascular diseases and endothelial-to-mesenchymal transition (EndMT), a cellular transdifferentiation process in which endothelial cells (ECs) partially lose their identity and acquire mesenchymal phenotypes. EC reprogramming represents an innovative strategy in regenerative medicine to prevent deleterious effects induced by cardiovascular diseases.
METHODS: Using partial reprogramming of ECs, via overexpression of Oct-3/4-Sox-2-Klf-4 (OSK) transcription factors, we aimed to bring ECs back to a youthful phenotype in hypertension. Primary ECs were infected with lentiviral vectors (LVs) containing the specific EC promoter Cdh5 (cadherin-5) and the reporter EGFP (enhanced green fluorescent protein) with empty vector (LV control) or LV with Oct-3/4-Sox-2-Klf-4. Confocal microscopy and Western blotting analysis were used to confirm OSK overexpression. Cellular migration, senescence, and apoptosis were evaluated. Human aortic ECs from normotensive patients and patients with hypertension were analyzed after OSK treatments for eNOS (endothelial nitric oxide synthase), nitric oxide (NO), and genetic profile. Male and female normotensive (BPN/3J or blood pressure normal mouse strain) and hypertensive (BPH/2J or blood pressure high mouse strain) mice were treated with LV control or LV with Oct-3/4-Sox-2-Klf-4 and evaluated 10 days post-infection. The blood pressure, cardiac function, vascular reactivity of small arteries, and EndMT inhibition were analyzed.
RESULTS: OSK overexpression induced partial EC reprogramming in vitro, and these cells had lower migratory capability. OSK treatment of BPH/2J mice reduced blood pressure and resistance arteries hypercontractility, via the attenuation of endothelial-to-mesenchymal transition and elastin breaks. EGFP was detected in vivo in the prefrontal cortex. OSK-treated hypertensive human aortic ECs showed high eNOS activation and NO production, with low reactive oxygen species (ROS) formation. Single-cell RNA analysis showed that OSK alleviated EC senescence and EndMT, restoring their phenotypes in human aortic ECs from patients with hypertension.
CONCLUSIONS: Overall, these data indicate that OSK treatment and EC reprogramming can decrease blood pressure and reverse hypertension-induced vascular damage.
