Multi-omic and multispecies analysis of right ventricular dysfunction

Abstract

Background: Right ventricular failure (RVF) is a leading cause of morbidity and mortality in multiple cardiovascular diseases, but there are no treatments for RVF as therapeutic targets are not clearly defined. Contemporary transcriptomic/proteomic evaluations of RVF are predominately conducted in small animal studies, and data from large animal models are sparse. Moreover, a comparison of the molecular mediators of RVF across species is lacking.

Methods: Transcriptomics and proteomics analyses defined the pathways associated with cardiac magnetic resonance imaging (MRI)-derived values of RV hypertrophy, dilation, and dysfunction in control and pulmonary artery banded (PAB) pigs. Publicly available data from rat monocrotaline-induced RVF and pulmonary arterial hypertension patients with preserved or impaired RV function were used to compare molecular responses across species.

Results: PAB pigs displayed significant right ventricle/ventricular (RV) hypertrophy, dilation, and dysfunction as quantified by cardiac magnetic resonance imaging. Transcriptomic and proteomic analyses identified pathways associated with RV dysfunction and remodeling in PAB pigs. Surprisingly, disruptions in fatty acid oxidation (FAO) and electron transport chain (ETC) proteins were different across the 3 species. FAO and ETC proteins and transcripts were mostly downregulated in rats but were predominately upregulated in PAB pigs, which more closely matched the human response. All species exhibited similar dysregulation of the dilated cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy pathways.

Conclusions: The porcine metabolic molecular signature was more similar to human RVF than rodents. These data suggest there may be divergent molecular responses of RVF across species, and pigs may more accurately recapitulate metabolic aspects of human RVF.

Keywords: RV; cardiac MRI; comparative study; proteomics; transcriptomics.

Figure 1:. Cardiac MRI Identified Changes in RV Morphology and Function in PAB piglets.

PAB piglets have reduced RVEF (control: 64.0±4.1, PAB: 38.3±2.1, p=0.0014) (A), elevated RV mass (control: 25.5±2.0, PAB:58.0±8.2 , p=0.0085) (B), RV dilation, RV ESV (control: 29.0±5.6, PAB: 70.8±8.4, p=0.0063) (C) and RV EDV (control: 79.3±7.8, PAB:113.5±11.7, p=0.0509) (D), impaired RV-PA coupling (control: 1.9±0.4, PAB:0.6±0.1, p=0.0286) (E), and elevated NPPB (control: 6.1±2.1, PAB: 97.9±50.3, p=0.0286) (F). p-values determined by unpaired t-test (A-E), and Mann-Whitney test (F) when there was unequal variance between groups.

Figure 2:. Transcriptomics and Proteomics Analyses Demonstrated PAB RVs Exhibit a Distinct Molecular Signature as Compared to Controls.

Hierarchical cluster analysis (A) of transcriptomic data reveal control and PAB piglets (n=3) are molecularly distinct. Volcano plot (B) found 1530 transcripts were different between control and PAB piglets. 792 were elevated and 738 were reduced in PAB piglets. The top 15 most important transcripts for distinguishing between control and PAB piglets as determined by Random Forest analysis (C). Hierarchical cluster analysis of proteomics data demonstrate distinct profiles when comparing control and PAB piglets (D). 710 proteins were upregulated and 103 were downregulated by volcano blot (E). The top 15 most important proteins for differentiating between control and PAB piglets as determined by Random Forest analysis (F).

Figure 3:. Correlational analysis of proteomics and transcriptomics data identified Lysosome, Metabolism of Lipids, and Fatty Acid Metabolism as key pathways associated with RVEF.

Proteins (left) and transcripts (right) r-value for RVEF in the (A) Lysosome, (B) Metabolism of Lipids, and (C) Fatty Acid Metabolism pathways. Hierarchical cluster analysis of proteomics and transcriptomics data demonstrate differences between control and PAB piglets. Molecules identified in both proteomics and transcriptomics analyses were highlighted in red. Scale bars show relative changes between groups.

Figure 4:. Correlational analysis of proteomics and transcriptomics data identified Dilated Cardiomyopathy and Arrhythmogenic Right Ventricular Cardiomyopathy as key pathways associated with RV hypertrophy.

Proteins (left) and transcripts (right) with r-value for RV mass in the (A) Dilated Cardiomyopathy, and (B) Arrhythmogenic Right Ventricular Cardiomyopathy pathways. Hierarchical cluster analysis of proteomics and transcriptomics data demonstrate differences between control and PAB piglets. Molecules identified in both proteomics and transcriptomics analyses were highlighted in red. Scale bars show relative changes between groups.

Figure 5:. Correlational analysis of proteomics and transcriptomics data identified Metabolism, Citric Acid Cycle and Respiratory Electron Transport, and Respiratory Electron Transport pathways associated with RV ESV.

Proteins (left) and transcripts (right) with r-value for RV ESV in the (A) Metabolism, (B) Citric Acid Cycle and Respiratory Electron Transport and (C) Respiratory Electron Transport Pathways. Hierarchical cluster analysis of proteomics and transcriptomics data demonstrate differences between control and PAB piglets. Scale bars show relative changes between groups.

Figure 6:. Comparison of Mitochondrial Fatty Acid Beta-Oxidation and Respiratory Electron Transport Pathways Across Species.

Hierarchical cluster analyses of proteomics data from rat, pig, and human experiments analyzing the proteins in the (A) Mitochondrial Fatty Acid Beta-Oxidation and (C) Respiratory Electron Transport pathways. Hierarchical cluster analyses of transcriptomics data from rat, pig, and human experiments analyzing the (B) Mitochondrial Fatty Acid Beta-Oxidation and (D) Respiratory Electron Transport pathways. Scale bars show relative changes between groups.