ABSTRACT
Dysregulation of extracellular signal-regulated kinases (ERK1/2) is linked to several diseases including heart failure, genetic syndromes and cancer. Inhibition of ERK1/2, however, can cause severe cardiac side-effects, precluding its wide therapeutic application. ERKT188-autophosphorylation was identified to cause pathological cardiac hypertrophy. Here we report that interference with ERK-dimerization, a prerequisite for ERKT188-phosphorylation, minimizes cardiac hypertrophy without inducing cardiac adverse effects: an ERK-dimerization inhibitory peptide (EDI) prevents ERKT188-phosphorylation, nuclear ERK1/2-signaling and cardiomyocyte hypertrophy, protecting from pressure-overload-induced heart failure in mice whilst preserving ERK1/2-activity and cytosolic survival signaling. We also examine this alternative ERK1/2-targeting strategy in cancer: indeed, ERKT188-phosphorylation is strongly upregulated in cancer and EDI efficiently suppresses cancer cell proliferation without causing cardiotoxicity. This powerful cardio-safe strategy of interfering with ERK-dimerization thus combats pathological ERK1/2-signaling in heart and cancer, and may potentially expand therapeutic options for ERK1/2-related diseases, such as heart failure and genetic syndromes.
Subject(s)
Cardiotoxicity , Cell-Penetrating Peptides/pharmacology , Dimerization , Extracellular Signal-Regulated MAP Kinases/metabolism , MAP Kinase Signaling System , Animals , Cell Culture Techniques , Cell-Penetrating Peptides/chemical synthesis , Cell-Penetrating Peptides/toxicity , Colonic Neoplasms/drug therapy , Colonic Neoplasms/metabolism , Drug Delivery Systems , Extracellular Signal-Regulated MAP Kinases/drug effects , Heart Failure/drug therapy , Heart Failure/metabolism , Humans , Lung Neoplasms/drug therapy , Lung Neoplasms/metabolism , MAP Kinase Signaling System/drug effects , MAP Kinase Signaling System/physiology , Mice , Mice, Inbred C57BL , Molecular Medicine , Rats , Rats, Sprague-Dawley , Signal TransductionABSTRACT
In heart failure therapy, it is generally assumed that attempts to produce a long-term increase in cardiac contractile force are almost always accompanied by structural and functional damage. Here we show that modest overexpression of the Raf kinase inhibitor protein (RKIP), encoded by Pebp1 in mice, produces a well-tolerated, persistent increase in cardiac contractility that is mediated by the ß1-adrenoceptor (ß1AR). This result is unexpected, as ß1AR activation, a major driver of cardiac contractility, usually has long-term adverse effects. RKIP overexpression achieves this tolerance via simultaneous activation of the ß2AR subtype. Analogously, RKIP deficiency exaggerates pressure overload-induced cardiac failure. We find that RKIP expression is upregulated in mouse and human heart failure, indicative of an adaptive role for RKIP. Pebp1 gene transfer in a mouse model of heart failure has beneficial effects, suggesting a new therapeutic strategy for heart failure therapy.