Fig. 1.

Cardiac-specific PHB2 deficiency aggravated DOX-induced cardiomyopathy in mice.

(A) Top 5 GO hits for biological process (BP), cellular component (CC), and molecular function (MF) analysis using differentially expressed proteins in mouse heart lysates from DOX and saline groups. (B and C) Representative immunoblotting images and quantification of PHB2 in mouse heart lysates with and without DOX challenge (β-Tubulin used as an internal control, n = 6 per group). (D) Relative mRNA levels of PHB2 in mouse heart lysates with and without DOX challenge quantified using RT-qPCR (GAPDH used as an internal control, n = 6 per group). (E) Representative immunoblotting of PHB2 in heart lysates from PHB2^flox/flox and PHB2^CKO mice (β-Tubulin used as an internal control). (F) Flow chart depicting experimental strategy for cardiac-specific PHB2 conditional knockout through tamoxifen administration in PHB2^flox/flox mice in DOX cardiomyopathy. (G) Body weight and heart weight-to-tibial length ratio (n = 6–12 per group). (H) Serum levels of creatine kinase-muscle/brain (CK-MB) and lactic acid dehydrogenase (LDH) (n = 6 per group). (I) Representative images of hematoxylin and eosin (H&E) staining (upper), wheat germ agglutinin (WGA) staining (middle), and picrosirius red (PSR) staining (lower) of myocardial sections. (J) Quantification of cardiomyocyte area in WGA staining (n = 6 per group). (K) Quantitation of the fibrotic area in PSR staining (normalized to the entire field, n = 6 per group). (L and M) Representative echocardiographic images and echocardiographic measurements (n = 6–21 per group). IVSd, interventricular septum thickness at diastole; LVPWd, left ventricular posterior wall thickness at diastole; LVEDD, left ventricular end-diastolic dimension; LVESD, left ventricular end-systolic dimension; EF, ejection fraction; FS, fractional shortening; HR, heart rate; CO, cardiac output. Mean ± SEM. **p < 0.01, ****p < 0.0001, ns, no significance. For statistical analysis, unpaired student's t-test was used for C-D; two-way ANOVA with Tukey's test for multiple comparisons was used for G-H, J-K, and M. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)