Upregulation of miR-361-3p suppresses serotonin-induced proliferation in human pulmonary artery smooth muscle cells by targeting SERT

Abstract

Background Abnormal proliferation of pulmonary artery smooth muscle cells (PASMCs) is a key mechanism in pulmonary arterial hypertension (PAH). Serotonin (5-hydroxytryptamine, 5-HT) can induce abnormal proliferation of PASMCs. The role of miR-361-3p in serotonin-induced abnormal PASMCs proliferation remains unclear. Methods The miR-361-3p level was analyzed in plasma from PAH patients and normal controls and in human PASMCs (hPASMCs) using RT-PCR. The hPASMCs were transfected with an miR-361-3p mimic and then treated with serotonin. Untransfected hPASMCs were used as the control. Cell proliferation was evaluated using an MTS assay and 5-ethynyl-2′-deoxyuridine (EdU) staining. The cell cycle stages were evaluated using flow cytometry. The association between miR-361-3p and serotonin transporter (SERT) was determined using a luciferase reporter assay and anti-AGO2 RNA immunoprecipitation assay. The protein expression was evaluated via western blotting. Results The miR-361-3p level was lower in plasma from PAH patients than in plasma from the any of the normal control subjects. The mean pulmonary arterial pressure, pulmonary vascular resistance and pulmonary vascular resistance index were higher in PAH patients whose miR-361-3p level was lower than the median value for patients than in those whose miR-361-3p level was higher than the median. Serotonin treatment reduced miR-361-3p expression in the hPASMCs. MiR-361-3p overexpression suppressed cell proliferation, promoted apoptosis, induced G1 arrest, and decreased the phosphorylation level of ERK1/2 in serotonin-treated hPASMCs. SERT was identified as an miR-361-3p target. Its overexpression alleviated the effect of miR-361-3p overexpression on serotonin-induced hPASMC proliferation and upregulation of phosphorylated ERK1/2. Conclusions The miR-361-3p level is lower in the plasma of PAH patients. Upregulation of miR-361-3p suppresses serotonin-induced proliferation of hPASMCs by targeting SERT. Our results suggest that miR-361-3p is a potential therapeutic target in PAH.

SOX17 is a Critical Factor in Maintaining Endothelial Function in Pulmonary Hypertension by an Exosome‐Mediated Autocrine Manner

“…Previous studies have confirmed the downregulation of miR‐224‐5p and miR‐361‐3p in IPH patients. [ 22 , 23 ] Here, we also verified miR‐224‐5p and miR‐361‐3p were downregulated in the lung tissue homogenate of IPH patients (Figure S12d , Supporting Information) and increased in HPAECs and pulmonary arteries of mice treated with SOX17‐associated exosomes (Figure 4d,e ). It is indicating that miR‐224‐5p and miR‐361‐3p were transported to recipient cells by SOX17‐associated exosomes.…”

“…Then, the functional experiment further verified the inhibiting effect of miR-224-5p and miR-361-3p on the increased activity of caspase 3 induced by serum-free and the increased activity of NFĸB p65 induced by hypoxia and TNF𝛼. The reduced expression of miR-224-5p and miR-361-3p were further confirmed in the lung tissues of IPH patients, which has also been reported in PH-associated [22,23] miR-224-5p and miR-361-3p alone played a protective role under various experimental conditions, and their combined application greatly enhanced this efficiency. It has been demonstrated that the combined application of multiple miRNAs in disease-relevant pathways mediates cancer progression [48,49] and cardiac dysfunction.…”

Molecular Pathways in Pulmonary Arterial Hypertension

“…SERT is a target for miR-361-3p action, as upregulation of SERT attenuated the effects of decreased miR-361-3p on serotonin induced pulmonary artery smooth muscle cell proliferation. The authors thus concluded that miR-361-3p may be a potential target for PAH therapies [ 73 ].…”

The Role and Mechanism of Gut Microbiota in Pulmonary Arterial Hypertension

“…Similarly, the 5-HTT inhibitors, fluoxetine and citalopram, impeded human PASMC growth in vitro by blocking SERT expression [ 106 ]. miR-361-3p overexpression suppressed serotonin-induced human PASMC proliferation by lowering SERT levels [ 107 ], indicating that SERT induced PASMC proliferation. Because SERT mediates indolamine uptake in SMCs, the mitogenic effect of 5-HT on PASMCs is ascribed to 5-HT internalization by SERT.…”