FIGURE 6.

Heat shock protein beta‐1 (HSPB1) inhibition abolishes the ameliorative effect of reticulon 3 (RTN3) knockout on heart failure (HF) after myocardial infarction (MI). (A) Representative western blots of HSPB1 different forms in primary mouse cardiomyocytes treated with J2. (B) Representative western blots of HSPB1 different forms in hearts of mice intraperitoneally injected with J2 for 14 days. (C) The timeline of the experimental design for J2 in vivo application. (D) Representative echocardiography images at the indicated time points before and after J2 in vivo application. Echocardiography parameters, including ejection fraction (EF), fractional shortening (FS), left ventricular internal dimension at systolic phase (LVIDs), and left ventricular internal dimension at diastolic phase (LVIDd), were calculated (n = 8 per group). ^* p < 0.05, RTN3 ^CKO + MI + vehicle versus RTN3 ^fl/fl + MI + vehicle; ^# p < 0.05, RTN3 ^CKO + MI + J2 versus RTN3 ^CKO + MI + vehicle; ^## p < 0.01, RTN3 ^CKO + MI + J2 versus RTN3 ^CKO + MI + vehicle. (E) Representative Masson trichrome staining images and quantification of infarct size 28 days post‐MI (n = 5 per group). Scale bar = 2 mm. (F) Relative mRNA levels of ANP, BNP, Col1a1, and Col3a1 in hearts 28 days post‐MI (n = 4 per group). (G) Representative western blots of mitochondrial electron transport chain (ETC) complex subunits in indicated groups. (H) ATP production in the hearts of indicated mice (n = 6 per group). (I) Representative western blots and quantitative analysis of TLR4 and p‐IκBα in indicated groups (n = 6 per group). (J) Representative western blots and quantitative analysis of p‐NFκB or NFκB in cytoplasm and nucleus (n = 6 per group). Data are presented as mean ± standard error of the mean (SEM). Statistical significance was assessed by one‐way analysis of variance (ANOVA) with a Bonferroni post hoc test. ^* p < 0.05, ^** p < 0.01, ^*** p < 0.001.