Blood biomarkers in Takotsubo syndrome point to an emerging role for inflammaging in disease pathophysiology

Abstract

Takotsubo syndrome (TTS), an acute cardiac condition characterized by transient wall motion abnormalities mostly of the left ventricle, results in difficulties in diagnosing patients. We set out to present a detailed blood analysis of TTS patients analyzing novel markers to understand the development of TTS. Significant differences in pro-inflammatory cytokine expression patterns, sex steroid and glucocorticoid receptor (GR) expression levels were observed in the TTS patient collective. Remarkably, the measured catecholamine serum concentrations determined from TTS patient blood could be shown to be two orders of magnitude lower than the levels determined from experimentally induced TTS in laboratory animals. Consequently, exposure of endothelial cells and cardiomyocytes in vitro to such catecholamine concentrations did not damage the cellular integrity or function of neither endothelial cells forming the blood brain barrier, endothelial cells derived from myocardium nor cardiomyocytes in vitro. Computational analysis was able to link the identified blood markers, specifically, the pro-inflammatory cytokines and glucocorticoid receptor GR to microRNA (miR) relevant in the ontogeny of TTS (miR-15), and inflammation (miR-21, miR-146a), respectively. Amongst the well-described risk factors of TTS (older age, female gender), inflammaging-related pathways were identified to add to these relevant risk factors or prediagnostic markers of TTS.