98%
921
2 minutes
20
Background: Ventricular arrhythmias (VAs) in chronic ischemic heart failure (HF) are associated with high mortality and often refractory to beta-blocker treatment, highlighting the need for alternative therapeutic targets.
Objective: This study investigates the role of neuropeptide Y (NPY), a neurotransmitter released during sympathoexcitation, in the pathogenesis of VAs associated with ischemic chronic HF following myocardial infarction (MI).
Methods: Using a mouse model of ischemic chronic HF after coronary ligation, we employed biochemical, electrophysiological, and calcium ion (Ca) imaging analyses to investigate the proarrhythmic mechanisms of NPY.
Results: Immunohistochemical staining revealed a significantly elevated NPY expression in both the MI and border zone, consistent with findings in human autopsy samples. In cardiomyocytes isolated from ischemic HF mice, NPY treatment increased Ca waves at a dose that did not elicit this response in normal heart cardiomyocytes, an effect suppressed by NPY Y1 receptor blocker. Additionally, the NPY treatment elevated the frequency of delayed afterdepolarizations at the membrane potential level. Similarly, NPY-induced VAs that were suppressed by the NPY Y1 receptor blocker in Langendorff-perfused chronic ischemic failed hearts at a concentration that had no effect in normal hearts.
Conclusion: We identified structural and functional changes in NPY within an chronic ischemic HF model, leading to increased arrhythmogenicity through Ca mishandling. Therefore, targeting NPY signaling may offer a novel therapeutic approach for treating VAs in patients with chronic ischemic HF.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.hrthm.2025.08.011 | DOI Listing |
Behav Brain Res
September 2025
Department of Rehabilitation Medicine, the First Affiliated Hospital of Nanchang University, Nanchang, China. Electronic address:
Glutamate-mediated excitotoxicity represents a common pathomechanism in neurological disorders. As the predominant glutamate transporter in the central nervous system, glutamate transporter 1 (GLT-1, known as EAAT2 in humans) plays a crucial role in maintaining glutamate homeostasis and preventing excitotoxicity through its Na⁺-dependent transport mechanism. Key functions of GLT-1 include reducing extracellular glutamate concentration, regulating calcium homeostasis, suppressing oxidative stress, preserving mitochondrial integrity, and modulating neuroinflammatory processes by limiting microglial activation.
View Article and Find Full Text PDFJ Mol Histol
September 2025
Ultrasonography Department, Jinjiang Municipal Hospital (Shanghai Sixth People's Hospital Fujian), Quanzhou, 362200, China.
Renal ischemic disease represents a severe clinical pathological condition commonly observed in acute kidney injury (AKI), renal transplantation, and kidney surgery. It leads to renal tubular epithelial cell damage, inflammatory responses, and cell death, potentially progressing to chronic kidney disease (CKD) or even renal failure, significantly impairing patients' quality of life and survival rates. Current therapeutic strategies for renal ischemia-reperfusion injury (IRI) include pharmacological interventions, cell therapy, and gene therapy, yet their efficacy remains limited and may be accompanied by adverse effects.
View Article and Find Full Text PDFJACC Case Rep
September 2025
Cardiology Unit, Cardiovascular Department, Humanitas Gavazzeni, Bergamo, Italy.
Background: We present a multimodality imaging study of a rare case of postsurgical chronically evolved pseudoaneurysm with a possible rupture buffered by the huge thrombus.
Case Summary: A patient known for previous late presentation myocardial infarction complicated by shock and ventricular septal defect and treated with surgical repair and triple coronary artery bypass grafting, was directed to our hospital for severe mitral regurgitation. Computed tomography, cardiac magnetic resonance, and echocardiography, in a multimodality approach, revealed a huge postsurgical cardiac pseudoaneurysm, with an extensive thrombus and the native pericardium not perfectly distinguishable from pseudoaneurysm tissue or surgical patch.
Am J Physiol Heart Circ Physiol
September 2025
Hematology and Transfusion Center, University of Campinas - UNICAMP, Campinas. São Paulo, Brazil. 13083-878.
Intravascular hemolysis (IVH), a pathological process associated with various conditions, triggers inflammatory responses, yet the key molecular drivers of these responses are poorly defined, particularly within the vasculature. To explore the role of NLRP3 inflammasome- and caspase-1-dependent pathways in IVH-induced vascular dysfunction, we used models of acute and chronic IVH, alongside heme stimulation of endothelial cells, thereby isolating this disease mechanism from its etiological causes. IVH induced rapid inflammatory responses in C57BL/6J mice, including IL-1β release within 15 minutes, and NLRP3-dependent caspase-1 activation in circulating leukocytes.
View Article and Find Full Text PDFAnn Vasc Surg
September 2025
Department of Cardiovascular Surgery, Hiroshima University Hospital, 1-2-3Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
Background: Polypharmacy or hyperpolypharmacy in elderly patients has been associated with poor prognosis and cardiovascular events due to side effects and drug interactions. Patients with chronic limb-threating ischemia (CLTI) have many comorbidities that may need multiple drugs. The purpose of this study is to evaluate clinical outcomes in these patients with or without hyperpolypharmacy.
View Article and Find Full Text PDF