ABSTRACT
Objective:To explore the effect of endothelin-1 on atrial ifbrosis in patients with atrial ifbrillation (AF). Methods: A total of 72 patients with thoracotomy were studied, the patients were divided into 2 groups:AF group, n=39 and Sinus rhythm (SR) group, n=33. The mRNA and protein expressions of endothelin-1 (ET-1), platelet derived growth factor-B (PDGF-B) and collagen I (COL1) in right atrial appendage (RAA) tissue were measured by RT-PCR and Western blot analysis;meanwhile, the impact of ET-1 stimulation and non-selective ET-1 receptor antagonist (sulfafurazole SIZ) on PDGF-B mRNA and protein expressions in H9c2 cells were measured. Results: ①The RAA tissue mRNA and protein expressions in AF group were higher than those in SR group, as for ET-1 (2.830 ± 2.276) vs (1.220 ± 0.887) and (0.835 ± 0.241) vs (0.286 ± 0.083), both P Conclusion: ET-1 plays an important role in AF occurrence which might be related to PDGF-B regulation.
ABSTRACT
Objective To investigate the effect of microRNA-101 (miRNA-101) on atrial fibrosis in human chronic atrial fibrillation (AF). Methods Right atrial appendages were obtained from 59 patients (30 with AF) undergoing cardiac surgery, including 47 patients with valve heart disease and 12 patients with congenital heart disease. The expression of miRNA-101 was determined by quantitative real-time PCR in the right atrial appendages of patients with and without AF. The cell-specific localization of miRNA-101 was detected by in situ hybridization assay. The mRNA and protein expression levels of transforming growth factor β typeⅠreceptor (TGFβRⅠ) and collagen type I (COL1) were determined by quantitative real-time PCR and Western-blot assay, respectively. Collagen in the right atrial appendages was observed by Masson staining assay. Results The expression of miRNA-101 was found to be significantly down-regulated in AF patients compared with patients with sinus rhythm (SR) (P 0.05). But the protein expression of TGFβRI in patients with AF was significantly higher than that of patients with SR (P < 0.05). The mRNA and protein expressionsl of COL1 were significantly higher in patients with AF than thoset of patients with SR (P < 0.05). The collagen was significantly increased in patients with AF than that of patients with SR (P < 0.05). Conclusions Downregulation of miRNA-101 may contribute to atrial fibrosis in human atrial fibrillation by targeting TGFβRⅠ.