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Background: Takotsubo syndrome (TTS) is characterized by an acute left ventricular dysfunction and is associated with life-threating complications in the acute phase. The underlying disease mechanism in TTS is still unknown. A genetic basis has been suggested to be involved in the pathogenesis.
Objectives: The aims of the study were to establish an in vitro induced pluripotent stem cell (iPSC) model of TTS, to test the hypothesis of altered β-adrenergic signaling in TTS iPSC-cardiomyocytes (CMs), and to explore whether genetic susceptibility underlies the pathophysiology of TTS.
Methods: Somatic cells of patients with TTS and control subjects were reprogrammed to iPSCs and differentiated into CMs. Three-month-old CMs were subjected to catecholamine stimulation to simulate neurohumoral overstimulation. We investigated β-adrenergic signaling and TTS cardiomyocyte function.
Results: Enhanced β-adrenergic signaling in TTS-iPSC-CMs under catecholamine-induced stress increased expression of the cardiac stress marker NR4A1; cyclic adenosine monophosphate levels; and cyclic adenosine monophosphate-dependent protein kinase A-mediated hyperphosphorylation of RYR2-S2808, PLN-S16, TNI-S23/24, and Cav1.2-S1928, and leads to a reduced calcium time to transient 50% decay. These cellular catecholamine-dependent responses were mainly mediated by β-adrenoceptor signaling in TTS. Engineered heart muscles from TTS-iPSC-CMs showed an impaired force of contraction and a higher sensitivity to isoprenaline-stimulated inotropy compared with control subjects. In addition, altered electrical activity and increased lipid accumulation were detected in catecholamine-treated TTS-iPSC-CMs, and were confirmed by differentially expressed lipid transporters CD36 and CPT1C. Furthermore, we uncovered genetic variants in different key regulators of cardiac function.
Conclusions: Enhanced β-adrenergic signaling and higher sensitivity to catecholamine-induced toxicity were identified as mechanisms associated with the TTS phenotype. (International Takotsubo Registry [InterTAK Registry] [InterTAK]; NCT01947621).
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http://dx.doi.org/10.1016/j.jacc.2017.06.061 | DOI Listing |
ACS Sens
September 2025
College of Chemistry, Beijing Normal University, Beijing 100875, China.
Dopamine (DA) signaling is essential for neurodevelopment and is particularly sensitive to disruption during adolescence. Protein restriction (PR) can impair DA dynamics, yet mechanistic insights remain limited due to challenges in real-time neurochemical sensing. Here, we present aptCFE, a robust implantable aptamer-based sensor fabricated via a reagent-free, 3 min electrochemical conjugation (E-conjugation) using amine-quinone chemistry.
View Article and Find Full Text PDFChannels (Austin)
December 2025
Biorheology Research Laboratory, Faculty of Health, Griffith University, Gold Coast, Australia.
The hallmarks of mechanosensitive ion channels have been observed for half a century in various cell lines, although their mechanisms and molecular identities remained unknown until recently. Identification of the bona fide mammalian mechanosensory Piezo channels resulted in an explosion of research exploring the translation of mechanical cues into biochemical signals and dynamic cell morphology responses. One of the Piezo isoforms - Piezo1 - is integral in the erythrocyte (red blood cell; RBC) membrane.
View Article and Find Full Text PDFJ Agric Food Chem
September 2025
College of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou 225009, China.
Rising atmospheric CO exposes plants to high-CO environments, while excessive nitrogen fertilizer use degrades soil, highlighting the need to reduce nitrogen input and cultivate vigorous cucumber seedlings under HC-LN conditions. Calcineurin B-like proteins (CBLs) sense calcium signals and regulate carbon/nitrogen metabolism via CBL-interacting protein kinases (CIPKs), though their roles in cucumber under HC-LN conditions are unclear. Here, we identified seven and 19 genes.
View Article and Find Full Text PDFAnnu Rev Pharmacol Toxicol
September 2025
1Department of Physiology and Pharmacology and Center for Molecular Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden; email:
In light of the success of blockbuster drugs for type 2 diabetes and obesity based on the GLP-1 hormone, drugmakers have concentrated their efforts on developing new and improved variations that address the route of administration, dosing, pathway selectivity, or polypharmacology. While some of these modifications have demonstrated improved efficacy in clinical studies and offered exciting opportunities for treating other diseases, drug-induced shifts to the conformational landscape of target receptors may have consequences for side effects. Our review summarizes advances in the understanding of the biochemistry, pharmacogenomics, and molecular pharmacology of incretins and their cognate receptors.
View Article and Find Full Text PDFPhysiology (Bethesda)
September 2025
Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA 94304.
Canonical activation of G-protein coupled receptors (GPCRs) by hormone binding occurs at the plasma membrane, resulting in the diffusion of second messengers to intracellular effector sites throughout the cell. In contrast, recent evidence suggests that functional GPCRs can induce signaling from distinct intracellular domains, contributing to specificity in signaling. Functional adrenergic receptors have been identified at intracellular sites in the cardiac myocyte such as endosomes, the sarcoplasmic reticulum, the Golgi and the inner nuclear membrane.
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