The circulating level of miR-122 is a potential risk factor for endothelial dysfunction in young patients with...

MicroRNAs are key molecules involved in the regulation of endothelial function. They are important risk factors and biomarkers for the development of hypertension related to endothelial dysfunction. However, the gene expression patterns associated with hypertension development related to endothelial dysfunction have not been fully elucidated. We conducted a case-control study of 65 patients with essential hypertension (EH) and 61 controls without EH. Plasma levels of miR-122 and its target protein high-affinity cationic amino acid transporter 1 (CAT-1) were measured by qRT-PCR and ELISA, respectively. miR-122 expression in plasma of patients with EH was significantly higher than that of the control group (p = 0.001), while CAT-1 expression in patients with EH was significantly lower than that in the control group (p = 0.018). miR-122 expression in plasma of young patients with EH was significantly higher than that in young people without EH (p = 0.0004), and CAT-1 expression in plasma of young patients with EH was also significantly lower than that of the control group (p = 0.002). CAT-1 expression in the plasma of young participants was significantly higher than that of individuals aged ≥40 years (p = 0.003), whereas miR-122 expression was significantly lower (p = 0.001). We showed that among patients with EH, the high expression of miR-122 contributed to endothelial dysfunction by suppressing the expression of the CAT-1 protein, which led to a decrease in CAT-1 expression in plasma. Therefore, high expression of miR-122 appears to be a risk factor for endothelial dysfunction in EH, especially in younger patients.