Figure 7
Formation of stress granules (SGs) in hypoxic cardiomyocytes following stimulation with bone marrow mononuclear cell (BM-MNC)-conditioned medium. (A) Box plots show median values, 10th and 90th percentiles, and minimum/maximum values of hypoxic cardiomyocytes that express eIF3-positive SGs following stimulation with unconditioned medium or conditioned media from unfractioned, SDF-1non or SDF-1-mig BM-MNCs. Human angiogenin was used as a positive control. Values are means ± standard error of the mean. ***P < 0.001, versus unconditioned medium; # P < 0.001, versus unfractioned; +++ P < 0.001, versus SDF-1non. (B) Representative fluorescent microscopy image of SGs. (C) Inhibition of angiogenin by ribonuclease/angiogenin inhibitor 1 (RNH1) results in a reduction in the ability of SDF-1mig cell-conditioned medium to stimulate the formation of SGs. Representative images of eIF3 granules in cardiomyocytes exposed to SDF-1mig BM-MNC-conditioned medium in the absence (i) or presence (ii) of RNH1 inhibitor. Myocyte cytoplasm is labeled with alpha sarcomeric actinin (iii). Nuclei are depicted in blue (4′,6-diamidino-2-phenylindole; DAPI). (iv) Graph showing average results. **P < 0.05, versus unconditioned medium (UCM); # P < 0.05, versus of SDF-1mig cell-conditioned medium (CM). (D) Inhibition of angiogenin by RNH1 results in a reduction in the ability of SDF-1mig cell-conditioned medium to contrast cardiomyocyte death upon exposure to hypoxia. Round-shaped cells indicate dead cells, while rod-shaped cells are viable cells. *P < 0.05, versus UCM; # P < 0.05, versus of SDF-1mig cell CM. SDF-1mig, stromal cell-derived factor 1 migrated; SDF-1non, stromal cell-derived factor 1 non-migrated.