The application of kinomic array analysis to screen for altered kinases in atrial fibrillation remodeling.

BACKGROUND: Dysregulation of protein kinase-mediated signaling is an early event in many diseases, including the most common clinical cardiac arrhythmia, atrial fibrillation (AF). Kinomic profiling represents a promising technique to identify candidate kinases.

OBJECTIVE: Here we employ kinomic profiling to identify kinases altered in AF remodeling using atrial tissue from a canine AF-model (atrial tachypacing).

METHODS: Left atrial tissue obtained in a previous canine study was used for kinome array (containing 1024 kinase pseudo-substrates) analysis. Three groups of dogs were included: non-paced controls (C) and atrial tachypaced (TP) dogs, which were contrasted with geranylgeranylacetone (GGA) treated AF dogs, which are protected from AF promotion, to enhance specificity of detection of putative kinases.

RESULTS: While TP changed activity of 50 kinases, 40 of these were prevented by GGA and involved in differentiation and proliferation (SRC), contraction, metabolism, immunity, development, cell cycle (CDK4) and survival (Akt). Inhibitors of Akt (MK2206) and CDK4 (PD0332991) and overexpression of a dominant negative CDK4 phosphorylation mutant protected against tachypacing-induced contractile dysfunction in HL-1 cardiomyocytes. Moreover, AF patients show down- and upregulation of SRC and Akt phosphorylation, respectively, similar to findings of the kinome array.

CONCLUSION: Contrasting kinomic array analyses of control and treated subject offers a versatile tool to identify kinases altered in atrial remodeling due to tachypacing, which include Akt, CDK4 and SRC. Ultimately, pharmacological targeting of altered kinases may offer novel therapeutic possibilities to treat clinical AF.