EGFR/IGF1R Signaling Modulates Relaxation in Hypertrophic Cardiomyopathy

Abstract

BACKGROUND: Diastolic dysfunction is central to diseases such as heart failure with preserved ejection fraction and hypertrophic cardiomyopathy (HCM). However, therapies that improve cardiac relaxation are scarce, partly due to a limited understanding of modulators of cardiomyocyte relaxation. We hypothesized that cardiac relaxation is regulated by multiple unidentified proteins and that dysregulation of kinases contributes to impaired relaxation in patients with HCM. METHODS: We optimized and increased the throughput of unloaded shortening measurements and screened a kinase inhibitor library in isolated adult cardiomyocytes from wild-type mice. One hundred fifty-seven kinase inhibitors were screened. To assess which kinases are dysregulated in patients with HCM and could contribute to impaired relaxation, we performed a tyrosine and global phosphoproteomics screen and integrative inferred kinase activity analysis using HCM patient myocardium. Identified hits from these 2 data sets were validated in cardiomyocytes from a homozygous MYBPC3 c.2373insG HCM mouse model. RESULTS: Screening of 157 kinase inhibitors in wild-type (n=33) cardiomyocytes (n=24 563) resulted in the identification of 17 positive inotropes and 21 positive lusitropes, almost all of them novel. The positive lusitropes formed 3 clusters: cell cycle, EGFR (epidermal growth factor receptor)/IGF1R (insulin-like growth factor 1 receptor), and a small Akt (α-serine/threonine protein kinase) signaling cluster. By performing phosphoproteomic profiling of HCM patient myocardium (n=24 HCM and n=8 donors), we demonstrated increased activation of 6 of 8 proteins from the EGFR/IGFR1 cluster in HCM. We validated compounds from this cluster in mouse HCM (n=12) cardiomyocytes (n=2023). Three compounds from this cluster were able to improve relaxation in HCM cardiomyocytes. CONCLUSIONS: We showed the feasibility of screening for functional modulators of cardiomyocyte relaxation and contraction, parameters that we observed to be modulated by kinases involved in EGFR/IGF1R, Akt, cell cycle signaling, and FoxO (forkhead box class O) signaling, respectively. Integrating the screening data with phosphoproteomics analysis in HCM patient tissue indicated that inhibition of EGFR/IGF1R signaling is a promising target for treating impaired relaxation in HCM.

Identifying plasma proteomic signatures from health to heart failure, across the ejection fraction spectrum

“…Stage A/Healthy play a role in cardiac cell proliferation, differentiation and cardiac regeneration (i.e. Wtn signaling pathway) 39 , processes discriminating iHFrEF from HFpEF are involved in cardiac hypertrophy (PI3K-PKB/Akt signaling) and relaxation (EGF/EGFR signaling) 40 . Other pathways found for iHFrEF are related to oxidative stress control (c-Met signaling) 41 and activation of cardioprotective mechanisms (IL3 signaling) 42 , while for HFpEF mechanisms encompassed response to inflammation (EGF/EGFR signaling) 11 and glucose and lipid metabolism (Leptin signaling) 43 .…”

Biomarkers and Proteomics in Sarcomeric Hypertrophic Cardiomyopathy in the Young—FGF-21 Highly Associated with Overt Disease

“…There a few studies describing an upregulation of EGFR leading to remodelling of the desmosome by tyrosine phosphorylation of the plakoglobin, changing the interaction with desmoplakin in the desmosome, and you can speculate if this has implications in the pathogenesis of arrhythmogenic right ventricular cardiomyopathy (ARVC) [29]. In HCM, EGFR is not well described and there are a few animal studies recently publicized, describing activation of the EGFR pathway contributing to impaired relaxation in HCM [30]. However, we found changes in the opposite direction in human HCM with an OR for HCM of 0.1 (p = 0.013), Table 3.…”

Unraveling the Complexity: From Molecular Subtypes to Therapeutic Strategies in Heart Failure with Preserved Ejection Fraction and Atrial Fibrillation

“…What is worse -AF -also result in HFpEF through the bad side hemodynamic effects [37], and the HFpEF -at the same time -cause an AF -which is also bad -through the adverse consequences of the left atrial remodeling [38]. Atrial and ventricular remodeling happen at the same time; therefore, this synergistic effect of both conditions may arise and cause a worsening condition of patients with atrial fibrillation and HFpEF [39].…”