Heart Care Info - Heart Disease Prevention & Treatment

p53-Induced Adipose Tissue Inflammation Is Critically Involved in the Development of Insulin Resistance in Heart Failure

I Shimizu, Y Yoshida, T Katsuno, K Tateno... - Cell Metabolism, 2012 - Elsevier Several clinical studies have shown that insulin resistance is prevalent among patients with heart failure, but the underlying mechanisms have not been fully elucidated. Here, we report a mechanism of insulin resistance associated with heart failure that involves upregulation ...

Figure 7. Mechanism of p53-Induced Adipose Tissue Inflammation during Heart Failure(A) Dihydroethidium (DHE) staining (red) of preadipocytes treated with vehicle (Cont) or palmitic acid (500 μM) for 10 min. Nuclei were stained with Hoechst dye (blue). Scale bar indicates 50 μm. The right graph indicates the quantitative data on DHE-positive area (n = 4).(B) Immunofluorescent staining for γ-H2AX (red) in preadipocytes treated with vehicle (Cont) or palmitic acid (500 μM) for 1 hr. Nuclei and plasma membranes were stained with Hoechst dye (blue) and Wheat Germ agglutinin lectin (green). Scale bar indicates 50 μm.(C) Western blot analysis of phospho-p53 and p53 expression in preadipocytes treated with vehicle (Cont) or palmitic acid (500 μM).(D) Small-interfering RNA targeting p53 (sip53) or negative control RNA (si NC) was introduced into preadipocytes treated with or without palmitic acid (500 μM) for 12 hr. The NF-κB activity was examined by luciferase assay (n = 5).(E) Real-time PCR assessing the expression of Cdkn1a (p21) and Ccl2 (MCP1) levels in preadipocytes prepared in Figure 7D (n = 9). The effect of small-interfering RNA targeting the NF-κB component p50 (sip50) on the expression of Ccl2 (MCP1) was also examined (n = 9).(F) Dihydroethidium (DHE) staining (red) in adipose tissue from sham-operated (Sham) and TAC mice. Nuclei were stained with Hoechst dye (blue). Scale bar indicates 20 μm. The right graph indicates the quantitative data on DHE-positive area (n = 5).(G) The number of γ-H2AX-positive nuclei (white arrows and inset) in adipose tissue of mice at 6 weeks after sham operation (Sham) or TAC procedure was estimated by immunofluorescent staining for γ-H2AX (red) (n = 5). Nuclei and plasma membranes were stained with Hoechst dye (blue) and Wheat Germ agglutinin lectin (green). Scale bar indicates 50 μm.(H) The number of p50-positive nuclei in adipose tissue of adipocyte-specific p53-deficient mice (adipo-p53 KO) and littermate controls (Cont) at 6 weeks after sham operation (Sham) or TAC procedure was estimated by immunofluorescent staining for p50 (n = 6). Data are shown as the means S.E.M. p < 0.05, p < 0.01.