Fig 1.
Echocardiographic measurements of left ventricular remodeling.
The consecutive measurements of the echocardiographic parameters were acquired at baseline (0, immediate post-operation), 7 days, 14 days, and 28 days after surgical procedure. *P <0.05 between the MI group vs. sham group. †P <0.05 between the MI + GW group vs. sham group. MI, myocardial infarction only; MI + GW, MI treated with GW610742, IVS, interventricular septal thickness; LVEDD, left ventricular dimension at end-diastole; LVESD, left ventricular dimension at end-systole; FS, fractional shortening; EF, ejection fraction; SV, stroke volume. Sham (n = 3/each day), MI (n = 28 of baseline, n = 18 of 7days, n = 17 of 14 days, n = 6 of 28days), MI + GW (n = 31 of baseline, n = 19 of 7days, n = 15 of 14 days, n = 6 of 28days).
Fig 2.
Effects of the PPAR-δ agonist GW610742 on fibrosis.
Representative images from sham-operated (Sham), myocardial infarction alone (MI), and MI treated with GW610742 (MI + GW) rats on day 7 (A) and day 14 (B) after MI. Densitometric analysis shows MT staining, and collagen I-stained tissue, confirming the differences in fibrosis between the groups. Values are represented as the mean ± the standard error of the mean. *P < 0.05 and **P < 0.01 vs. the corresponding MI group. Scale bars = 100 μm. Sham, sham-operated; MI, myocardial infarction only; MI+GW, MI treated with GW610742; MT, Masson’s trichrome stain; Col I, collagen-1. Sham (n = 3/each day), MI (n = 7/each day), MI + GW (n = 7/each day).
Fig 3.
Effects of the PPAR-δ agonist GW610742 on angiogenesis.
Representative images from the sham-operated (Sham), myocardial infarction alone (MI), and MI treated with GW610742 (MI + GW) groups on day 7 (A) and day 14 (B) post-surgery. Images using Masson’s trichrome staining (MT) show vessels (arrows) in the heart post-operation. The immunoreactivity and positive cell numbers for CD31 and Ki-67 (arrows) were counted in each group post-operation. Values are represented as the mean ± the standard error of the mean (SEM). *P < 0.05 and vs. **P < 0.01 the corresponding MI group. Scale bars = 100 μm and 50 μm for MT, CD31, and Ki-67 staining, respectively. Sham (n = 3/each day), MI (n = 7/each day), MI + GW (n = 7/each day).
Fig 4.
Expression of PPAR-δ in the infarcted zone.
PPAR-δ protein expression in the infarct zone in a heart with MI. Representative blots for PPAR-δ expression from sham-operated (Sham) rats and rats with MI alone (MI) on day 1 through day 14 post-surgery. *P < 0.05. PPAR-δ, peroxisome proliferator-activated receptor-delta; Sham, sham-operated; MI, myocardial infarction. Sham (n = 4/each day), MI (n = 10/each day).
Fig 5.
Effects of GW610742 on TGF-β2 expression.
(A) TGF-β2 (12.5 kDa) expression was assessed by immunoblot analyses in all groups on day 3, 7, and day 14 following surgery. Densitometric analysis shows the relative levels of TGF-β2 expression in each group. α-tubulin (42 kDa), used as a loading control, was not different between the groups. Representative blots are derived from three separate experiments. Values are represented as the mean ± SEM. *P < 0.05 and **P < 0.01. Sham (n = 3), MI (n = 10), MI + GW (n = 10). (B) Representative immunohistochemical images for TGF-β2 from the MI alone (MI) group and the MI treated with GW610742 (MI + GW) group on day 7 post-surgery. Scale bars = 100 μm. TGF-β2, transforming growth factor-beta 2.
Fig 6.
Effects of GW610742 on MSC migration into the infarcted hearts.
(A) Rat cardiac cells on days 3 after MI were prepared from the ventricles, and adherent cells were stained with each antibody. “T” and “U”-gated cells (floating cells also have “T” and “U”-gated cells) were ruled out for analysis, and “AC” and “V”-gated cells were verified for MSC-phenotype analysis. MSC-positive cells were counted in “AC” and “V”-gated cells. (B) Serum from each group on each day was measured for PDGF-b, SDF-1α, MMP-9, bFGF, and VEGF using specific ELISA kit. Values are represented as the mean ± SEM. *P <0.05. MSC, mesenchymal stem cell; MI, myocardial infarction; PDGF-b, platelet-derived growth factor subunit B; MMP-9, matrix metallopeptidase 9; SDF-1α, stromal-derived factor-1 alpha; bFGF, basic fibroblast growth factor; VEGF, vascular endothelial growth factor. Sham (n = 3), MI (n = 7), MI + GW (n = 7).
Fig 7.
Effects of GW610742 on α-SMA and OB-cadexpression.
α-SMA (42 kDa) and OB-cad (120 kDa) expression were assessed by immunoblot analyses in all groups on days 3, 7 and 14 following surgery. Densitometric analysis shows the relative levels of α-SMA and OB-cad expression in each group. α-tubulin (42 kDa), used as a loading control, was not different between the groups. Representative blots are derived from three separate experiments. Values are represented as the mean ± SEM. *P <0.05 and **P < 0.01. OB-cad, osteoblast cadherin; α-SMA, α-smooth muscle actin. Sham (n = 3), MI (n = 10), MI + GW (n = 10).