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Aims: The most efficient way to acutely restore sinus rhythm from atrial fibrillation (AF) is electrical cardioversion, which is painful without adequate sedation. Recent studies in various experimental models have indicated that optogenetic termination of AF using light-gated ion channels may provide a myocardium-specific and potentially painless alternative future therapy. However, its underlying mechanism(s) remain(s) incompletely understood. As brief pulsed light stimulation, even without global illumination, can achieve optogenetic AF termination, besides direct conduction block also modulation of action potential (AP) properties may be involved in the termination mechanism. We studied the relationship between optogenetic AP duration (APD) and effective refractory period (ERP) prolongation by brief pulsed light stimulation and termination of atrial tachyarrhythmia (AT).
Methods And Results: Hearts from transgenic mice expressing the H134R variant of channelrhodopsin-2 in atrial myocytes were explanted and perfused retrogradely. AT induced by electrical stimulation was terminated by brief pulsed blue light stimulation (470 nm, 10 ms, 16 mW/mm) with 68% efficacy. The termination rate was dependent on pulse duration and light intensity. Optogenetically imposed APD and ERP changes were systematically examined and optically monitored. Brief pulsed light stimulation (10 ms, 6 mW/mm) consistently prolonged APD and ERP when light was applied at different phases of the cardiac action potential. Optical tracing showed light-induced APD prolongation during the termination of AT.
Conclusion: Our results directly demonstrate that cationic channelrhodopsin activation by brief pulsed light stimulation prolongs the atrial refractory period suggesting that this is one of the key mechanisms of optogenetic termination of AT.
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http://dx.doi.org/10.1016/j.yjmcc.2023.03.006 | DOI Listing |
Virol Sin
September 2025
State Key Laboratory of Virology and Biosafety, RNA Institute, College of Life Sciences and Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, 430072, China; Institute for Vaccine Research at Animal Bio-safety Level Ⅲ Laboratory, Wuhan University, Wuhan, 430071, China.
Since the outbreak of SARS-CoV-2 in late 2019, the cumulative number of confirmed cases worldwide has surpassed 778 million, and the number of deaths has exceeded 7 million, posing a significant threat to human life and health while inflicting enormous losses on the global economy. At the stage where sequential immunization is recommended, there is a pressing demand for mRNA vaccines that can be rapidly adapted to new sequences, are easy to industrialize, and exhibit high safety and effectiveness. We developed a lipid nanoparticle (LNP) system, designated as WNP, which facilitates essentially in situ expression at the injection site and results in lower levels of pro-inflammatory factors in the liver, thus enhancing its safety compared to liver-targeted alternatives.
View Article and Find Full Text PDFCell Rep
September 2025
Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China; Pôle de Recherches Sino-Français en Science du Vivant et Gé
RNA helicase DDX3X is generally implicated in inflammasome activation and anti-viral responses. We characterize the common features of scattered DDX3X mutations in lymphoid cancers using molecular dynamics simulation and crystallization, thereby demonstrating their crucial role in Epstein-Barr virus (EBV) lytic gene-driven oncogenic processes. The DDX3X mutation is significantly related to impaired stimulator of interferon genes (STING)/ interferon regulatory factor 7 (IRF-7)/interferon (IFN)-α/β-mediated innate immunity, overexpression of EBV lytic gene BNLF2b, and increased formation of R-loops.
View Article and Find Full Text PDFCarbohydr Polym
November 2025
Engineering Technology Research Center of Drug Carrier of Guangdong, Department of Biomedical Engineering, Jinan University, Guangzhou 510632, China; Guangdong Provincial Key Laboratory of Spine and Spinal Cord Reconstruction, The Fifth Affiliated Hospital (Heyuan Shenhe People's Hospital), Jinan Un
Recently, a variety of stimulus-responsive hydrogel platforms have been developed, specifically designed to respond to changes in physiological signals within the disease microenvironment. However, due to the restricted regulation of drug release behavior in vivo by such hydrogel systems, the precise control of drug release kinetics has not been achieved. Therefore, developing precise drug delivery platforms that enable programmable and "on-off" delivery remains a challenge in this field.
View Article and Find Full Text PDFBMJ Open
September 2025
Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Introduction: Blue light (peak wavelength 442 nm) has been shown to modulate the immune response in preclinical models of intra-abdominal sepsis and pneumonia. pathways involve optic nerve stimulation with transmission to the central nervous system, activation of parasympathetic pathways terminating at the spleen, and downstream immune effects including decreased inflammatory tissue damage and improved pathogen clearance. Related effects on pain mediators including proinflammatory cytokines (interleukin 6, TNF- α) and autonomic tone (increased parasympathetic outflow) suggest possible analgesic properties that would be highly relevant to a trauma population.
View Article and Find Full Text PDFBioresour Technol
September 2025
College of Water Science, Beijing Normal University, Beijing 100875, China.
The bioconversion of purple non-sulfur photosynthetic bacteria (PNSB) based on real food waste (FW) fermentation broth is crucial for FW resource recovery. This study enhanced the bioconversion efficiency of FW fermentation broth by PNSB through light intensity and photoperiod optimization, while elucidating the synthesis mechanisms of high-value cell inclusions. The results demonstrated that 4500 lx-L/D = 16/8 significantly enhanced R.
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