Oxygen supply for ischemic brain tissue during stroke is critical to neuroprotection. Remote ischemic conditioning (RIC) treatment is effective for stroke. However, it is not known whether RIC can improve brain tissue oxygen supply. In current study, we employed a mouse model of stroke created by middle cerebral artery occlusion (MCAO) to investigate the effect of RIC on oxygen supply to the ischemic brain tissue using a hypoxyprobe system. Erythrocyte oxygen-carrying capacity and tissue oxygen exchange were assessed by measuring oxygenated hemoglobin and oxygen dissociation curve. We found that RIC significantly mitigated hypoxic signals and decreased neural cell death, thereby preserving neurological functions. The tissue oxygen exchange was markedly enhanced, along with the elevated hemoglobin P50 and right-shifted oxygen dissociation curve. Intriguingly, RIC markedly elevated 2,3-biphosphoglycerate (2,3-BPG) levels in erythrocyte, and the erythrocyte 2,3-BPG levels were highly negatively correlated with the hypoxia in the ischemic brain tissue. Further, adoptive transfusion of 2,3-BPG-rich erythrocytes prepared from RIC-treated mice significantly enhanced the oxygen supply to the ischemic tissue in MCAO mouse model. Collectively, RIC protects against ischemic stroke through improving oxygen supply to the ischemic brain tissue where the enhanced tissue oxygen delivery and exchange by RIC-induced 2,3-BPG-rich erythrocytes may play a role.
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http://dx.doi.org/10.1177/0271678X20952264 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720.
Polysaccharide monooxygenase (PMO) catalysis involves the chemically difficult hydroxylation of unactivated C-H bonds in carbohydrates. The reaction requires reducing equivalents and will utilize either oxygen or hydrogen peroxide as a cosubstrate. Two key mechanistic questions are addressed here: 1) How does the enzyme regulate the timely and tightly controlled electron delivery to the mononuclear copper active site, especially when bound substrate occludes the active site? and 2) How does this electron delivery differ when utilizing oxygen or hydrogen peroxide as a cosubstrate? Using a computational approach, potential paths of electron transfer (ET) to the active site copper ion were identified in a representative AA9 family PMO from (PMO9E).
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Helmholtz-Zentrum Hereon, Institute of Membrane Research, Max Planck Str. 1, 21502, Geesthacht, Germany.
This work proposes a fuel cell power supply system for underwater applications (e.g., autonomous underwater vehicles), where artificial gills, based on a polymer membrane, harvest the required oxygen from the ambient water.
View Article and Find Full Text PDFCurr Cardiol Rep
January 2025
Department of Cardiovascular & Thoracic Surgery, Sandra Atlas Bass Heart Hospital at North Shore University Hospital, Northwell Health, 300 Community Drive, 1 DSU, Manhasset, NY, 11030, USA.
Purpose Of Review: This article discusses a tailored approach to managing cardiogenic shock and temporary mechanical circulatory support (tMCS). We also outline specific mobilization strategies for patients with different tMCS devices and configurations, which can be enabled by this tailored approach to cardiogenic shock management.
Recent Findings: Safe and effective mobilization of patients with cardiogenic shock receiving tMCS can be accomplished.
Cells
December 2024
Beijing Institute of Brain Disorders, Capital Medical University, Beijing 100054, China.
Neurovascular coupling (NVC) refers to the process of local changes in cerebral blood flow (CBF) after neuronal activity, which ensures the timely and adequate supply of oxygen, glucose, and substrates to the active regions of the brain. Recent clinical imaging and experimental technology advancements have deepened our understanding of the cellular mechanisms underlying NVC. Pathological conditions such as stroke, subarachnoid hemorrhage, cerebral small vascular disease, and vascular cognitive impairment can disrupt NVC even before clinical symptoms appear.
View Article and Find Full Text PDFInvestig Clin Urol
January 2025
National Research Center for Sexual Medicine and Department of Urology, Inha University College of Medicine, Incheon, Korea.
Purpose: To investigate the therapeutic potential of eliminating insulin-like growth factor-binding protein 5 (IGFBP5) expression in improving erectile function in mice with cavernous nerve injury (CNI)-induced erectile dysfunction (ED).
Materials And Methods: Eight-week-old male C57BL/6 mice were divided into four groups: a sham-operated group and three CNI-induced ED groups. The CNI-induced ED groups were treated with intracavernous injections 3 days before the CNI procedure.
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