GP130 Antagonism Enhances Porcine RV Function

Abstract

Background: Right ventricular (RV) dysfunction is a risk factor for death in multiple cardiovascular diseases, but RV-enhancing therapies are lacking. Inhibition of GP130 (glycoprotein-130) signaling with the small molecule SC144 improves RV function in rodent RV dysfunction via anti-inflammatory and metabolic mechanisms. However, SC144's efficacy and molecular effects in a translational large animal model of RV dysfunction are unknown.

Methods: Four-week-old castrated male pigs underwent pulmonary artery banding (PAB). After 3 weeks, PAB pigs were randomized into 2 groups (daily injections of SC144 [2.2 mg/kg, PAB-SC144, n=5] or vehicle [PAB-Veh, n=5] for 3 weeks). Five age-matched pigs served as controls. Cardiac magnetic resonance imaging quantified RV size/function. Right heart catheterization evaluated hemodynamics. Single-nucleus RNA sequencing delineated cell-type-specific changes between experimental groups. Electron microscopy evaluated RV mitochondrial morphology. Phosphoproteomics identified dysregulated RV kinases. Lipidomics and metabolomics quantified lipid species and metabolites in RV tissue and serum. Quantitative proteomics examined RV mitochondrial protein regulation. Confocal microscopy evaluated alterations in cardiomyocyte size, macrophage abundances, capillary density, and pericyte/endothelial cell localization patterns.

Results: SC144 significantly improved RV ejection fraction (control: 60±4%; PAB-Veh: 22±10%; PAB-SC144: 37±6%) without altering RV afterload. Single-nucleus RNA sequencing demonstrated that PAB-Veh pigs had lower cardiomyocyte and higher macrophage/lymphocyte/pericyte/endothelial cell abundances as compared with control, and many of these changes were blunted by SC144. Immunohistochemistry validated the reduction in RV macrophage infiltration by SC144. Both transcriptomics and proteomics approaches demonstrated that SC144 combatted the downregulation of cardiomyocyte metabolic genes/proteins induced by PAB. Kinome enrichment analysis suggested SC144 counteracted RV mTORC1 (mammalian target of rapamycin complex 1) activation. Correspondingly, SC144 rebalanced the RV autophagy pathway proteins and improved mitochondrial morphology. Integrated lipidomics, metabolomics, and proteomics analyses revealed that SC144 restored fatty acid metabolism. Finally, CellChat analysis, cardiomyocyte RNAseq analysis, and histological examination suggested SC144 rebalanced pericyte-endothelial cell interactions and blunted cardiomyocyte HIF1 (hypoxia-induced factor 1) activation.

Conclusions: GP130 antagonism blunts RV immune cell infiltration, reduces proinflammatory gene programs in macrophages and lymphocytes, rebalances autophagy, and preserves fatty acid metabolism in cardiomyocytes, and restores endothelial cell and pericyte homeostasis to mitigate cardiomyocyte hypoxia and ultimately augments RV function.

Keywords: autophagy; inflammation; lipidomics; metabolism; ventricular function, right.