Roles of Catecholamines and Inflammation in Endothelial Dysfunction: a Study Using Takotsubo Syndrome Patient-specific hiPSC-ECs

BACKGROUND: Takotsubo syndrome (TTS), also known as stress-induced cardiomyopathy, is characterized by transient left ventricular dysfunction often triggered by emotional or physical stress. Catecholamines are believed to play a pivotal role in the pathogenesis of TTS, including endothelial dysfunction. This study aimed to elucidate the catecholamine-induced endothelial dysfunction using patient-specific induced pluripotent stem cell-derived endothelial cells (hiPSC-ECs) from TTS patients. METHODS: hiPSC-ECs derived from a TTS patient (TTS-hiPSC-ECs) and three healthy donors (HD-hiPSC-ECs) were treated with epinephrine (Epi), Lipopolysaccharide (LPS), or a combination of both, and cell functional responses were evaluated. RESULTS: Epi exposure significantly impaired endothelial cell functions, evidenced by reduced cell migration, nitric oxide (NO) production, Dil-Ac-LDL uptake, mitochondrial membrane potential (MMP), ATP production, and inhibited tube formation and wound healing in both HD-hiPSC-ECs and TTS-hiPSC-ECs. Additionally, catecholamine treatment resulted in increased concentrations of endothelin-1 (ET-1), angiotensin II (Ang II), and reactive oxygen species (ROS) in the supernatants of both cell types. Elevated Mincle expression and pro-inflammatory cytokines, including IL-6 and IL-1β, along with reduced IL-4 protein expression, were observed in both HD-hiPSC-ECs and TTS-hiPSC-ECs. Furthermore, LPS treatment enhanced Mincle, IL-6, and IL-1β protein expression and reduced IL-4 levels in both cell types. The combination of LPS and Epi enhanced not only the level of those inflammatory factors but also the PI3K/NF-κB signaling pathway in both HD-hiPSC-ECs and TTS-hiPSC-ECs. Strikingly, TTS-hiPSC-ECs showed abnormal features even without an Epi challenge. CONCLUSIONS: The study first reveals functional abnormalities of hiPSC-ECs from a TTS patient and underscores the critical involvement of inflammatory signaling in catecholamine-induced endothelial dysfunction in TTS.