Acute cardiac hypoxia produces life-threatening elevations in late sodium current (I) in the human heart. Here, we show the underlying mechanism: hypoxia induces rapid SUMOylation of Na1.5 channels so they reopen when normally inactive, late in the action potential. Na1.5 is SUMOylated only on lysine 442, and the mutation of that residue, or application of a deSUMOylating enzyme, prevents hypoxic reopenings. The time course of SUMOylation of single channels in response to hypoxia coincides with the increase in I, a reaction that is complete in under 100 s. In human cardiac myocytes derived from pluripotent stem cells, hypoxia-induced I is confirmed to be SUMO-dependent and to produce action potential prolongation, the pro-arrhythmic change observed in patients.
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http://dx.doi.org/10.1016/j.celrep.2020.01.025 | DOI Listing |
Biomater Adv
December 2024
College of Materials Science and Engineering, Jilin Institute of Chemical Technology, Jilin City 132022, Jilin Province, PR China. Electronic address:
Monotherapy has poor accuracy and is easily restricted by tumor microenvironment (TME). Remodeling components of the TME to activate multimodal cancer therapy with high precision and efficiency is worth exploring. A multifunctional nanoreactor was fabricated by decorating chlorin e6-modified and PEGylated hyaluronic acid bearing diethylenetriamine-conjugated dihydrolipoic acid on the surface of glucose oxidase (GOx)-loaded hollow mesoporous CuS nanoparticles (labeled as GOx@HCuS@HA).
View Article and Find Full Text PDFFront Microbiol
December 2024
Department of Otolaryngology, Shenzhen Nanshan People's Hospital, Shenzhen, China.
Obstructive sleep apnea (OSA) is a state of sleep disorder, characterized by repetitive episodes of apnea and chronic intermittent hypoxia. OSA has an extremely high prevalence worldwide and represents a serious challenge to public health, yet its severity is frequently underestimated. It is now well established that neurocognitive dysfunction, manifested as deficits in attention, memory, and executive functions, is a common complication observed in patients with OSA, whereas the specific pathogenesis remains poorly understood, despite the likelihood of involvement of inflammation.
View Article and Find Full Text PDFSmall
December 2024
Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Chemical Resource Engineering, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
Tumor hypoxia and heat resistance as well as the light penetration deficiency severely compromise the phototherapeutic efficacy, developing phototherapeutic agents to overcome these issues has been sought-after goal. Herein, a diradical-featured organic small-molecule semiconductor, namely TTD-CN, has been designed to show low exciton binding energy of 42 meV by unique dimeric π-π aggregation, promoting near-infrared (NIR) absorption beyond 808 nm and effective photo-induced charge separation. More interestingly, its redox potentials are tactfully manipulated for water splitting to produce O and reduction of O to generate O .
View Article and Find Full Text PDFExp Neurol
December 2024
Department of Neurology, Brain Research Institute, Niigata University, 1-757 Asahimachi-dori, Chuoku, Niigata 951-8585, Japan. Electronic address:
Background: Despite advances in reperfusion therapies, ischemic stroke remains a major cause of long-term disability due to residual hypoxic lesions persisting after macrovascular reperfusion. These residual hypoxic lesions, caused by microvascular dysfunction, represent an important therapeutic target. We previously demonstrated that oxygen-glucose-deprived peripheral blood mononuclear cells (OGD-PBMCs) migrate to ischemic brain regions and promote functional recovery after stroke.
View Article and Find Full Text PDFIntroduction: Brain cholesterol relies on de novo biosynthesis and is crucial for brain development. Cholesterol synthesis is a complex series of reactions that involves more than twenty enzymes to reach the final product and generates a large number of intermediate sterols along two alternate pathways. This is a highly regulated and oxygen-dependent process, and thus sensitive to hypoxia.
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