Exercise Training Impacts Cardiac Mitochondrial Proteome Remodeling in Murine Urothelial Carcinoma

Abstract

Cardiac dysfunction secondary to cancer may exert a negative impact in patients' tolerance to therapeutics, quality of life, and survival. The aim of this study was to evaluate the potential therapeutic effect of exercise training on the heart in the setting of cancer, after diagnosis. Thus, the molecular pathways harbored in heart mitochondria from a murine model of chemically-induced urothelial carcinoma submitted to 8-weeks of high intensity treadmill exercise were characterized using mass spectrometry-based proteomics. Data highlight the protective effects of high intensity exercise training in preventing left ventricle diastolic dysfunction, fibrosis, and structural derangement observed in tumor-bearing mice. At the mitochondrial level, exercise training counteracted the lower ability to produce ATP observed in the heart of animals with urothelial carcinoma and induced the up-regulation of fatty acid oxidation and down-regulation of the biological process "cardiac morphogenesis". Taken together, our data support the prescription of exercise training after cancer diagnosis for the management of disease-related cardiac dysfunction.

Keywords: HPLC–MS/MS; cardiac morphogenesis; cardiac remodeling; metabolism; treadmill running.

Figure 1

Effect of N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) exposure and/or exercise training on serum levels of C-reactive protein, TWEAK and irisin. Representative immunoblots are shown above the correspondent graph (sample order has correspondence to the order of the groups presented in the graph). Values are expressed as mean ± standard deviation of n = 6 (* p < 0.05 vs. CONT+Sed; + p < 0.05 vs. CONT+Ex).

Figure 2

Effect of BBN exposure and/or exercise training on cardiac function in baseline and stress conditions: heart rate, left ventricular Pmax, dP/dtmax, EDP, dP/dtmin, Tau, Pmax_control/Pmax_test, dP/dtmax_control/dP/dtmax_test, EDP_control/EDP_test, dP/dtmin_control/dP/dtmin_test and Tau_control/Tau_test. Pmax, maximum pressure; dP/dtmax, peak rate of pressure rise; dP/dtmin, peak rate of pressure fall; EDP, end-diastolic pressure; Tau, time constant of ventricular pressure decay. Values are expressed as mean ± standard deviation of n = 15 for BBN groups and n = 7 for CONT groups (*** p < 0.001 vs. CONT+Sed; ++ p < 0.01 vs. CONT+Ex; # p < 0.05 vs. BBN+Sed).

Figure 3

Effect of BBN exposure and/or exercise training on histological appearance of cardiomyocytes stained with hematoxylin and eosin, and on myocardial fibrosis given by Picrosirius red staining (red for collagen and yellow for cardiac muscle). All microscopic fields were obtained with a magnification of 400×.

Figure 4

Effect of BBN exposure and/or exercise training on ATP synthase and citrate synthase activities, and on OXPHOS complexes subunits (complex I, CI-NDUFB8; complex II, CII-SDHB; complex III, CIII-UQCRC2; complex IV, CIV-MTCO1 and complex V, CV-ATP5A). Representative Western blots are shown above the correspondent graph (sample order has correspondence to the order of the groups presented in the graph). Values are expressed as mean ± standard deviation of n = 6 for BBN groups and n = 4 for CONT groups (** p < 0.01 vs. CONT+Sed; *** p < 0.001 vs. CONT+Sed; + p < 0.05 vs. CONT+Ex; +++ p < 0.001 vs. CONT+Ex; # p < 0.05 vs. BBN+Sed; ## p < 0.01 vs. BBN+Sed; ### p < 0.001 vs. BBN+Sed).

Figure 5

Normalized abundance of proteins in BBN+Sed vs. CONT+Sed and BBN+Ex vs. BBN+Sed groups. Proteins with log2 lower than 0.05 are not presented in the figure but are listed in Supplementary Table S1. Protein accession numbers are correlated to protein names in Supplementary Table S1.

Figure 6

ClueGo + CluePedia analysis of protein-protein interaction considering unique proteins and the ones present in significantly distinct levels (based on emPAI values) in the heart of CONT+Sed and BBN+Sed, and BBN+Sed and BBN+Ex animals. In BBN+Sed vs. CONT+Sed analysis, green nodes refer to the biological processes up-regulated in the BBN+Sed group and red nodes refer to the ones up-regulated in the CONT+Sed group. In BBN+Ex vs. BBN+Sed analysis, green nodes refer to the biological processes up-regulated in BBN+Ex and red nodes refer to the ones up-regulated in BBN+Sed. Node size and color intensity reflect the number of associated proteins.