Fig. 3: Effects of Retnla protein treatment on cardiomyocytes, cardiac fibroblasts, and macrophages.

A Cardiac function was assessed by echocardiography in wild type (WT, n = 13) and Retnla transgenic (TG) mice (n = 20) after myocardial infarction (MI). B Cardiomyocyte apoptosis (white arrows) in the peri-infarct area was determined by TUNEL staining. cTnI cardiac troponin I. (WT; n = 7, KO; n = 8). Scale bar, 200 μm. C, D Phosphorylation of stress-activated ERK and p38 and cell cycle arrest-related proteins p21, and were assessed in neonatal rat cardiomyocytes (CM) or neonatal rat cardiac fibroblasts (cFb) by western blotting. Cells were treated with veh or Retnla (500 ng/mL) for 24 h. E, F Expression of pro-apoptotic Bax and antiapoptotic Bcl2 was determined by western blot analysis in cardiomyocytes and cardiac fibroblasts treated with vehicle (veh) or Retnla (500 ng/mL) protein for 24 h. G The ratios of Bax to Bcl2 were calculated in cardiomyocytes and cardiac fibroblasts and showed significant difference. H, I Proliferation of cardiac fibroblasts were induced with FBS with or without Retnla treatment for 24 h. Proliferating cell markers, phosphorylated histone H3 (pH3) and Ki67, were used and quantified by counting pH3(+) cells (veh; n = 6, FBS; n = 9, FBS + Retnla; n = 8) and Ki67(+) cells (veh; n = 6, FBS; n = 10, FBS + Retnla; n = 7). J Induction of inducible nitric oxide synthase (iNOS), a pro-inflammatory marker, was assessed in RAW264.7 cells stimulated with lipopolysaccharide (LPS, 100 μg/mL) for 24 h in the presence of Retnla (500 ng/mL). K Bone marrow-derived macrophages (BMDMs) were derived from WT mice and Retnla KO, and stimulated with LPS (100 μg/mL) for 24 h. Induction of iNOS was compared by western blot. Data are represented as mean ± SEM. #P < 0.05, ##P < 0.01, ###P < 0.001 (by Student’s t test or one-way ANOVA with Bonferroni’s multiple comparisons test).