Fig. 7: Protectin D1 enhances muscle regeneration.
From: Bioactive lipid mediator class switching regulates myogenic cell progression and muscle regeneration
a Representative micrographs showing myosin heavy chain (MyHC, fuchsia) and DAPI (nuclei, blue) staining on myoblasts differentiated for 2 days and treated (twice per day) with Vehicle (Veh) or protectin-D1 (PD1). Scale bars = 50 μm. b Quantification of the fusion index of WT myoblasts differentiated for 2 days and treated with Vehicle (Veh) or protectin-D1 (PD1) (p = 0.0017). c, d Representative Western blots and quantification of ERK1/2 phosphorylation in myoblasts treated with PD1 for 0, 15, 30, 60, 120 min (0 vs. 30 p = 0.0282; 0 vs. 60 p = 0.0191). e Schematic showing the timeline of daily intraperitoneal (i.p.) injection of Protectin-D1 (PD1, 5 ug/kg/day), or vehicle (Veh) in Alox15-KO mice after cardiotoxin (CTX) injury (Created in BioRender)93. f Representative images of Laminin (green), DAPI (blue) staining on muscle sections of tibialis anterior (TA) muscle of Alox15-KO mice at 7 dpi (dpi) and injected daily with PD1 or Veh. Scale bars = 50 μm. g–i Quantification of Pax7+ cells (g) (p = 0.0494), Myog+ cells (h), and the minimal fiber diameter (MFD) (i) (p = 0.0301) in the TA muscles of Alox15-KO mice at 7 dpi (dpi) and injected daily with PD1 or Veh. j Representative images of embryonic MyHC (MYH3, green), Wheat Germ Agglutinin (WGA; connective tissue marker; red), DAPI (nuclei, blue) staining on sections of the TA muscle of Alox15-KO mice at 7 dpi and injected daily with PD1 or Veh. Scale bars = 50 μm. k Quantification of the number of MYH3+ myofibers in the TA muscles of Alox15-KO mice at 7 dpi and injected daily with PD1 or Veh (p = 0.0348). l Representative images of Dystrophin (fuchsia) and DAPI (nuclei, blue) staining on sections of the TA muscle of Alox15-KO mice at 7 dpi and injected daily with PD1 or Veh. Scale bars = 50 μm. m Quantification of the number of Dystrophin+ myofibers in the TA muscles of Alox15-KO mice at 7 dpi and injected daily with PD1 or Veh (p = 0.0018). n Representative images of Laminin (green) and DAPI (blue) staining on muscle sections of the TA muscle of Alox15-KO mice at 14 dpi and injected daily with PD1 or Veh. Scale bars = 50 μm. o–q Quantification of Pax7+ cells (o), Myog+ cells (p), and the minimal fiber diameter (q) (p = 0.025) in the TA muscles of Alox15-KO mice at 14 dpi and injected daily with PD1 or Veh. Results are expressed as mean +/- SEM. Black bars represent the Alox15-KO group and blue bars are Alox15-KO + PD1 group. n = 3 for panels (b, k, m); n = 5 panel (d); n = 6 for Alox15KO and n = 3 for Alox15KO + PD1 for panels (g, h, o, p); n = 4 for Alox15KO and n = 3 for Alox15KO + PD1 for panel (i); n = 7 for Alox15KO and n = 3 for Alox15KO + PD1 for panel (q). *p < 0.05, **p < 0.01, *** p < 0.001. 2-way Paired t-test (b), One-way repeated measure ANOVA with Uncorrected Fisher’s LSD multiple comparisons (d), 2-way unpaired t-test (g–i, k, m, o–q). Source data are provided as a Source Data file.
