Atrial fibrillation (AF) is the most frequent form of clinical
cardiac arrhythmias. Previous evidence proved that atrial anatomical remodeling (AAR) and atrial
electrical remodeling (AER) are crucial for the progression and maintenance of AF. This study is aimed at investigating the impact of the
glucagon-like peptide-1 (GLP-1) receptor agonist,
Liraglutide (Lir), on
atrial remodeling (AR) mouse model induced by chronic intermittent
hypoxia (CIH). C57BL/6 mice were categorized randomly into the control, Lir, CIH, and CIH+Lir groups. CIH was performed in CIH and CIH+Lir groups for 12 weeks. Lir (0.3 mg/kg/day, s.c) was administered to the Lir and CIH+Lir groups for four weeks, beginning from the ninth week of CIH. Meanwhile, echocardiography and right atrial endocardial electrophysiology via jugular vein, as well as induction rate and duration of AF, were evaluated. Masson and Sirius red staining assays were utilized to assess the extent of
fibrosis in the atrial tissue of the mice. Immunohistochemical staining, RT-qPCR, and Western blotting were performed to evaluate the marker levels of AAR and AER and the expression of genes and
proteins of the miR-21/PTEN/PI3K/AKT signaling pathway, respectively. ELISA was also performed to evaluate the changes of serum inflammatory factor levels. The CIH group exhibited significant AR, increased atrial
fibrosis, and a higher incidence rate of AF compared to the control group. Lir could significantly downregulate the
protein expression level in the PI3K/p-AKT pathway and upregulated that of
phosphatase and
tensin homolog deleted on chromosome ten (PTEN). Moreover, Lir downregulated the expression of miR-21. However, the
protein expressions of CACNA1C and KCNA5 in atrial tissue were not changed significantly. In addition, Lir significantly attenuated the levels of markers of
inflammation (TNF-α and IL-6) in the serum. In the mouse model of CIH, Lir treatment could ameliorate AR by the miR-21/PTEN/PI3K/AKT signaling pathway and modulation of inflammatory responses.