LED-Red regulates miR-136-5p to promote the proliferation of cardiomyocytes. miRNA sequencing analysis (A) Heat map (B) Volcano map to detect differentially expressed miRNAs after irradiation by LED-Red. (C) qRT-PCR to verify miRNA expression. **P < 0.01, ***P < 0.001 vs. Non-LED. After knockdown or overexpression of miR-21a-3P and miR-136-5p, respectively, the proliferation of CMs was detected by (D), (F) EdU, (E), (G) pH3 staining. CM proliferation was detected by (H) EdU, (I) pH3 after miR-136-5p-mimic combined with LED-Red treatment. n = 3. Scale bar = 20 μm. *P < 0.05, **P < 0.01, ***P < 0.001 vs. NC-mimic (or inhibitor), ###P < 0.001 vs. LED-Red+NC-mimic. The data represent the mean ± SEM.