In this study, we reported the first measurement of the dynamics of activation of caspase-8 in a single living cell. This measurement was conducted using a specially developed molecular sensor based on the FRET (fluorescence resonance energy transfer) technique. This sensor was constructed by fusing a CFP (cyan fluorescent protein) and a YFP (yellow fluorescent protein) with a linker containing a tandem caspase-8-specific cleavage site. The change of the FRET ratio upon cleavage was larger than 4-fold. Using this sensor, we found that during TNFalpha-induced apoptosis, the activation of caspase-8 was a slower process than that of caspase-3, and it was initiated much earlier than the caspase-3 activation. Inhibition of caspase-9 delayed the full activation of caspase-3 but did not affect the dynamics of caspase-8. Results of these single-cell measurements suggested that caspase-3 was activated by caspase-8 through two parallel pathways during TNFalpha-induced apoptosis in HeLa cells.
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http://dx.doi.org/10.1016/s0006-291x(03)00559-x | DOI Listing |
J Adv Res
December 2024
Department of Pharmacology, School of Basic Medical Sciences, Peking University Health Science Center, 38 Xueyuan Road, Haidian District, Beijing 100191, China; State Key Laboratory of Vascular Homeostasis and Remodeling, State Key Laboratory of Natural and Biomimetic Drugs, NHC Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Peking University, Beijing 100191, China; Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, Beijing 100191, China. Electronic address:
Introduction: Liver fibrosis is the common fate of NASH and poses a major health threat with very limited pharmacological treatments.
Objectives: This study aims to investigate the preventive effect of hinokitone (HO), an isolated compound from Agathis dammara, on NASH fibrosis and its underlying mechanism.
Methods: To investigate the effect of HO on NASH fibrosis, C57BL/6 mice were either fed a high-fat diet (HFD) in conjunction with intraperitoneal injection of CCl for 8 weeks or single CCl for 14 days to establish mouse liver fibrosis model, and HO was administered by gavage simultaneously.
Biomed Pharmacother
December 2024
Institute of Cell Biology, Biocenter, Medical University of Innsbruck, Innsbruck 6020, Austria; Department of Pediatrics I, Medical University of Innsbruck, Innsbruck 6020, Austria. Electronic address:
Urinary tract infections are among the most frequently occurring forms of infection, and inflammation and tissue damage contribute significantly to symptoms, e.g., dysuria and urge.
View Article and Find Full Text PDFRedox Biol
December 2024
School of Biological Sciences, Faculty of Science, The University of Hong Kong, Hong Kong Special Administrative Region; State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong Special Administrative Region. Electronic address:
Idiopathic inflammatory myopathy (commonly known as myositis) is a group of immune-related diseases characterized by muscle damage, weakness, and fatigue with unknown causes. Although overactivated innate immunity is a widely believed cause of myositis onset, the mechanism that provokes and maintains a high immune response in myositis patients is still unclear. This study aims to test if brain-derived neurotrophic factor (BDNF) deficiency per se is sufficient to cause myositis and determine its underlying mechanism.
View Article and Find Full Text PDFInt J Mol Sci
August 2024
Department of Orthopedics and Trauma Surgery, University Hospital Bonn, 53127 Bonn, Germany.
Inflammation models are widely used in the in vitro investigation of new therapeutic approaches for osteoarthritis. TNFα (tumor necrosis factor alpha) plays an important role in the inflammatory process. Current inflammation models lack uniformity and make comparisons difficult.
View Article and Find Full Text PDFCell Death Discov
July 2024
Department of Otorhinolaryngology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
Head and neck squamous cell carcinomas (HNSCCs) are cancers that arise in the mucosa of the upper aerodigestive tract. The five-year patient survival rate is ~50%. Treatment includes surgery, radiation, and/or chemotherapy and is associated with lasting effects even when successful in irradicating the disease.
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