LncRNA FOXC2-AS1 regulated proliferation and apoptosis of vascular smooth muscle cell through targeting miR-1253/FOXF1 axis in atherosclerosis.

OBJECTIVE: Atherosclerosis (AS) is the most dangerous factor for human death, which is responsible for coronary heart disease. Growing evidence has showed that long non-coding RNAs (lncRNAs) are involved in the development of AS. In this study, we mainly aimed at investigating the roles of FOXC2-AS1 in AS patients. PATIENTS AND METHODS: RT-PCR was performed to detect the expressions of FOXC2-AS1 and miR-1253 in serum samples of AS patients (n=35) and healthy volunteer (n=35). The correlation between FOXC2-AS1 and miR-1253 was further analyzed. Human vascular smooth muscle cells (VSMCs) were respectively treated with ox-LDL, IL-6, CRP, TNF-α and IL-8 to explore the affecting factors. P-FOXC2-AS1 was constructed and transfected into VSMCs. Cell proliferation abilities were measured by CCK-8 assay. Cell apoptotic rates were measured by flow cytometry (FACS) analysis. Western blot (WB) was performed to detect protein levels of FOXF1, Bcl-2, Bax and Cleaved Caspase3. Finally, luciferase gene reporter assay was performed to prove the relationships between FOXC2-AS1 and miR-1253, miR-1253 and FOXF1. RESULTS: We found that FOXC2-AS1 was significantly upregulated in AS patients, which could be induced by ox-LDL and IL-6 in VSMCs. MiR-1253 was decreased in AS patients, which was negatively correlated with FOXC2-AS1. Furthermore, FOXC2-AS1 overexpression promoted proliferation and inhibited apoptosis in VSMCs. Luciferase gene reporter assay showed that FOXC2-AS1 could bind to miR-1253 in VSMCs and 293 cells. Moreover, miR-1253 overexpression inhibited proliferation and promoted apoptosis of VSMCs. Luciferase reporter assay proved that miR-1253 could target at FOXF1 in VSMCs and 293 cells, which was reported to be associated with cell proliferation and apoptosis in some cancers. Additionally, miR-1253 mimic or GSK343, a FOXF1 inhibitor, was respectively transfected into VSMCs with p-FOXC2-AS1. Results showed that the promoted cell proliferation and inhibited cell apoptosis were reversed as well, confirming that FOXC2-AS1 promoted cell proliferation and inhibited apoptosis via miR-1253/FOXF1 signaling axis in AS patients. CONCLUSIONS: According to the results, we found that FOXC2-AS1 was upregulated in AS patients; furthermore, FOXC2-AS1 overexpression promoted cell proliferation and inhibited cell apoptosis via targeting miR-1253/FOXF1 signaling axis. Our results elucidated a potential mechanism underlying the role of FOXC2-AS1, which might be used as a promising marker and a potential target for AS patients.

Exchange-protein activated by cAMP (EPAC) regulates L-type calcium channel in atrial fibrillation of heart failure model.

OBJECTIVE: Both atrial fibrillation (AF) and heart failure (HF) are increasingly prevalent and related to high hospitalization rate and mortality. AF is a cause as well as a consequence of HF, with complicated interactions resulting in impairment of cardiac systolic and diastolic function. Conversely, the complex structural and neurohormonal alterations in HF contribute to the occurrence and development of AF. However, the molecular mechanism remains unclear. This study aims to explore the effect of Exchange-protein activated by cAMP 1 (EPAC1) on AF in isoproterenol (ISO)-induced HF and the potential molecular mechanism. MATERIALS AND METHODS: Mice and cultured isolated adult cardiomyocytes were treated with ISO and or not EPAC1 inhibitor CE3F4. Programmed electrical stimulation (PES) was performed to induce AF. EPAC1 expression was determined by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) and Western blot. Cellular electrophysiology was examined by whole cell patch clamp. RESULTS: Both mRNA and protein levels of EPAC1 were upregulated in HF mice. ISO increased the AF susceptibility, and the negative effect was deteriorated by CE3F4. ISO mediated high AF susceptibility of HF via prolonging action potential and exciting L-type calcium channel (LTCC). These could also be reversed by CE3F4 treatment. CONCLUSIONS: EPAC1 increased the AF susceptibility in ISO-induced HF mouse model via alternating LTCC.