Western blotting unraveled that AF rats presented higher protein levels of atrial fibrosis markers such as collage I, α-SMA, and TGFβ1 in myocardial tissues than control rats; however, treatment with Lv-miR-499-5p plasmids noticeably reduced the collage I, α-SMA, and TGFβ1 levels in AF rats (Figure 2d, p < 0.01). This evidence concerns the gene ACTA1 and atrial fibrillation.