Oxygen plays an important role in diverse biological processes. However, since quantitation of the partial pressure of cellular oxygen in vivo is challenging, the extent of oxygen perturbation in situ and its cellular response remains underexplored. Using two-photon phosphorescence lifetime imaging microscopy, we determine the physiological range of oxygen tension in osteoclasts of live mice. We find that oxygen tension ranges from 17.4 to 36.4 mmHg, under hypoxic and normoxic conditions, respectively. Physiological normoxia thus corresponds to 5% and hypoxia to 2% oxygen in osteoclasts. Hypoxia in this range severely limits osteoclastogenesis, independent of energy metabolism and hypoxia-inducible factor activity. We observe that hypoxia decreases ten-eleven translocation (TET) activity. Tet2/3 cooperatively induces Prdm1 expression via oxygen-dependent DNA demethylation, which in turn activates NFATc1 required for osteoclastogenesis. Taken together, our results reveal that TET enzymes, acting as functional oxygen sensors, regulate osteoclastogenesis within the physiological range of oxygen tension, thus opening new avenues for research on in vivo response to oxygen perturbation.
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http://dx.doi.org/10.15252/embr.202153035 | DOI Listing |
Inorg Chem
January 2025
School of Chemistry and Chemical Engineering, School of Pharmacy, Jiangsu University, Zhenjiang 212013, P. R. China.
Electrochemical water splitting is a promising method for the generation of "green hydrogen", a renewable and sustainable energy source. However, the complex, multistep synthesis processes, often involving hazardous or expensive chemicals, limit its broader adoption. Herein, a nitrate (NO) anion-intercalated nickel-iron-cerium mixed-metal (oxy)hydroxide heterostructure electrocatalyst is fabricated on nickel foam (NiFeCeOH@NF) via a simple electrodeposition method followed by cyclic voltammetry activation to enhance its surface properties.
View Article and Find Full Text PDFAdv Mater
January 2025
State Key Laboratory of Fine Chemicals, Department of Pharmacy, School of Chemical Engineering, Dalian University of Technology, Dalian, 116024, China.
Phytochlorins, a class of plant-derived tetrapyrroles, show great potential as sonosensitizers in sonodynamic therapy (SDT). The development of new phytochlorin-based sonosensitizers has significantly improved SDT, yet the absence of specialized sonodynamic systems limits their clinical translation. Herein, a dedicated ultrasound system along with a detailed step-by-step sonodynamic process from in vitro to in vivo is developed to activate phytochlorin-based sonosensitizers.
View Article and Find Full Text PDFBiogerontology
January 2025
Song Biotechnologies LLC., Baltimore, MD, 21030, USA.
Human populations are experiencing unprecedented growth and longevity with lingering knowledge gaps of the characteristics, mechanisms, and pathologies of senescence. Invasive measurements and long-term control conditions for longitudinal studies are infeasible, necessitating the need for surrogate animal models. Rats have short lifespans (2-3 years) with translatable cardiovascular systems, and Sprague Dawley microcirculatory preparations are key to studying the oxygen transport mechanisms critical to the loss of skeletal muscle function in aging.
View Article and Find Full Text PDFJ Cereb Blood Flow Metab
January 2025
AP-HP, Hôpital Lariboisière, Department of Anaesthesia and Critical Care, Paris, France.
In patients with acute brain injury (ABI), optimizing cerebral perfusion parameters relies on multimodal monitoring. This include data from systemic monitoring-mean arterial pressure (MAP), arterial carbon dioxide tension (PaCO), arterial oxygen saturation (SaO), hemoglobin levels (Hb), and temperature-as well as neurological monitoring-intracranial pressure (ICP), cerebral perfusion pressure (CPP), and transcranial Doppler (TCD) velocities. We hypothesized that these parameters alone were not sufficient to assess the risk of cerebral ischemia.
View Article and Find Full Text PDFBMJ Open
January 2025
Department of Anesthesiology, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China
Introduction: Preclinical studies have shown that oxygen therapy can improve ischaemic brain tissue oxygen tension, reduce reperfusion injury after revascularisation, promote neuroregeneration and inhibit inflammatory responses potentially exerting a beneficial effect after endovascular treatment (EVT) in patients with acute ischaemic stroke (AIS). However, the optimal fraction of inspired oxygen (FiO) during EVT under general anaesthesia is currently unknown. Therefore, we are conducting a randomised controlled trial (RCT) to evaluate the impact of high-concentration oxygen vs low-concentration normobaric oxygen on early neurological function after EVT.
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