miR-320a in serum exosomes promotes myocardial fibroblast proliferation via regulating the PIK3CA/Akt/mTOR signaling pathway in HEH2 cells
| Autor: | Brian Chi-Yan Cheng, Yi Zhang, Gan Luo, Li Wang, Ya-Zhou He, Shan Liang, Qing-Gao Wang, Li-Juan Li, Yun Ling |
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| Rok vydání: | 2020 |
| Předmět: |
Cancer Research
Oncogene Chemistry General Medicine Articles Exosome PIK3CA/Akt/mTOR signaling pathway medicine.anatomical_structure Immunology and Microbiology (miscellaneous) Gene expression Cancer research medicine exosome Myocardial fibrosis myocardial fibrosis Viability assay Fibroblast CHF Protein kinase B PI3K/AKT/mTOR pathway HEH2 cells |
| Zdroj: | Experimental and Therapeutic Medicine |
| ISSN: | 1792-1015 |
| Popis: | MicroRNAs (miRNAs/miRs) serve an important role in the pathogenesis of chronic heart failure (CHF). A number of reports have illustrated the regulatory effect of serum exosomal miRNA on myocardial fibrosis. The present study aimed to investigate the expression of miR-320a in serum exosomes, as well as the effect of miR-320a on myocardial fibroblast proliferation. Serum exosome samples from 10 patients with CHF and 5 healthy volunteers were obtained and characterized. mRNA and protein expression levels were measured via reverse transcription-quantitative PCR and western blotting, respectively. The content of soluble growth stimulation expressed gene 2 (sST2) was determined via ELISA. HEH2 cell viability and apoptosis were detected by performing MTT assays and flow cytometry, respectively. The results demonstrated that serum miR-320a expression levels and sST2 content were significantly increased in patients with CHF compared with healthy controls, and the expression of serum miR-320a was significantly correlated with clinical CHF indexes. miR-320a expression levels were significantly increased in exosomes isolated from patients with CHF compared with those isolated from healthy controls. Phosphoinositide-3-kinase catalytic α polypeptide gene (PIK3CA) expression levels and sST2 content were increased in HEH2 cells following transfection with miR-320a mimics compared with NC-mimic, whereas miR-320a inhibitor displayed contrasting effects by reduced the cell viability and apoptosis in myocardial fibroblasts compared with the NC-inhibitor group. The protein expression levels of collagen I, collagen III, α-smooth muscle actin, phosphorylated (p)-mTOR (ser 2448)/mTOR, p-Akt (ser 473)/Akt, p-Akt (thr 308)/Akt and PIK3CA were significantly increased in miR-320a mimic-transfected HEH2 cells compared with the NC-mimics groups. By contrast, miR-320a inhibitor notably downregulated the expression levels of these proteins compared with the NC-inhibitor group. Collectively, the results of the present study demonstrated that miR-320a promoted myocardial fibroblast proliferation via regulating the PIK3CA/Akt/mTOR signaling pathway in HEH2 cells, suggesting that serum exosomal miR-320a may serve as a potential biomarker for the diagnosis of CHF. |
| Databáze: | OpenAIRE |
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