Fibroblast growth factor 13 deficiency attenuates doxorubicin-induced cardiotoxicity by regulating Parkin-mediated myocardial injury

Figures

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  Figure 1 Fgf13 deficiency attenuates DOX-induced cardiac dysfunction in mice (A) Administration modes in mice. (B) Representative images of FGF13 protein levels in wild-type and Fgf13-knockout mice. (C) Quantitative data of the FGF13 protein (n = 3 in each group). (D) qPCR analysis of Fgf13 mRNA expression in myocardial tissues (n = 6 in each group). (E) Representative images of FGF13 protein levels in myocardial tissues. (F) Quantitative data of FGF13 expression in mice. G) Representative M-type echocardiograms of wild-type control mice (WT-con), cardiac Fgf13-knockout mice (KO-con), wild-type mice treated with DOX (WT-DOX), and Fgf13-knockout mice treated with DOX (KO-DOX). (H-K) Cardiac function was quantified, including ejection fraction (EF), fraction shortening (FS), left ventricular end-systolic diameter (LVIDs) and left ventricular end-diastolic diameter (LVIDd) (n = 5 in each group). *P < 0.05, **P < 0.01, and ***P < 0.001.

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  Figure 2 Fgf13 knockout inhibits DOX-induced myocardial injury (A–C) CK, CK-MB, and LDH activity in mouse serum (n = 9 in each group). (D–E) Schematic diagram of HE staining of the heart cross-sectional area for each group (n = 3 in each group). *P < 0.05, **P < 0.01, and ***P < 0.001.

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  Figure 3 Fgf13 knockout inhibits DOX-induced myocardial atrophy (A) Schematic diagram of representative heart tissue WGA staining for each group of mice (n = 3 in each group). (B) Quantification of the cardiomyocyte cross-sectional area after WGA staining (n = 3 in each group). (C) Body weight statistics of the mice in each group. (D) Heart weight/body weight ratios (n = 5 in each group). (E) Survival curves after doxorubicin treatment in WT or Fgf13-KO mice (n = 20 in each group). *P < 0.05, **P < 0.01, and ***P < 0.001.

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  Figure 4 Fgf13 deficiency inhibits DOX-induced cardiomyocyte apoptosis (A) Representative western blot results showing bax, bcl-2 and cleaved caspase 3 protein levels in the heart. (B–D) Quantification of the levels of apoptotic proteins (n = 3 in each group). (E) Representative TUNEL staining image of a myocardial section. (F) Results from the quantitative analysis of the nuclei of apoptotic cells in mouse hearts, as evaluated by TUNEL staining (n = 3 in each group). (G) Quantitative data of the JC-1 red-to-green fluorescence intensity ratio (n = 3 in each group). (H) Cyt-C mRNA levels in myocardial tissues (n = 3 in each group). *P < 0.05, **P < 0.01, and ***P < 0.001.

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  Figure 5 Interactions between FGF13, p53 and Parkin (A) Representative western blot results of p53 protein expression in the heart (n = 3 in each group). (B) Quantitative data of p53 expression in mice (n = 3 in each group). (C,D) Coimmunoprecipitation (Co-IP) assay confirmed the interaction between FGF13 and p53 in myocardial whole-cell lysates. (E) Representative western blot results of Parkin protein expression in the heart. (F) Quantitative data of Parkin expression in mice (n = 3 in each group). (G,H) The ability of FGF13 to bind to Parkin was confirmed by Co-IP. *P < 0.05, **P < 0.01, and ***P < 0.001.