Acute microglial activation plays an important role in neuroprotection. However, dysregulated, prolonged microgliosis exacerbates neurodegeneration through excessive release of pro-inflammatory cytokines and cytotoxic factors. Interferon-gamma (IFN-γ), an inflammatory cytokine, exacerbates the detrimental microglial response. Although various anti-inflammatory drugs have been evaluated as interventions for microglia-mediated neuroinflammation, no anti-inflammatories are in clinical use for microgliosis. The present study evaluated the anti-inflammatory mechanisms of oxysterols, blood brain barrier (BBB) penetrable bioactive lipids, revealing that this intervention suppresses neuroinflammation by disrupting membrane lipid raft formation and caveolae-mediated endosomal IFN-γ signaling. We find that 25-hydroxycholesterol (25-HC) rapidly repressed IFN-γ receptor trafficking to lipid rafts in microglia by disrupting raft formation, thereby suppressing microglial inflammatory response. IFN-γ treatment upregulated expression of Cav-1, a major component of caveolae, and IFN-γ signaling was sustained through Cav-1 signaling endosomes. 25-HC repressed IFN-γ induction of Cav-1 expression in microglia, and subsequently suppressed the chronic inflammatory response. Taken together, these findings demonstrated that 25-HC effectively regulate the inflammatory status of microglia by mediating the formation of rafts and caveolae-dependent signaling endosomes. Given the important roles of IFN-γ and microglia in the pathology of neurodegenerative brain diseases, a novel anti-inflammatory mechanism of 25-HC that is not receptor-dependent, but rather is related to the regulation of membrane rafts and caveolae, suggests a new therapeutic target for inflammatory neurodegenerations.
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http://dx.doi.org/10.1016/j.freeradbiomed.2021.11.017 | DOI Listing |
Front Biosci (Landmark Ed)
January 2025
Department of Neurology, Jinshan Hospital, Fudan University, 201508 Shanghai, China.
Background: Neuronal cholesterol deficiency may contribute to the synaptopathy observed in Alzheimer's disease (AD). However, the underlying mechanisms remain poorly understood. Intact synaptic vesicle (SV) mobility is crucial for normal synaptic function, whereas disrupted SV mobility can trigger the synaptopathy associated with AD.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
Sepsis is a life-threatening severe organ dysfunction, and the pathogenesis remains uncertain. Increasing evidence suggests that circRNAs, mRNAs, and microRNAs can interact to jointly regulate the development of sepsis. Identifying the interaction between ceRNA regulatory networks and sepsis may contribute to our deeper understanding of the pathogenesis of sepsis, bring new insights into early recognition and treatment of sepsis.
View Article and Find Full Text PDFJ Mater Chem B
January 2025
Department of Radiology, Huaxi MR Research Center (HMRRC), Institution of Radiology and Medical Imaging, Breast Center, Institute of Breast Health Medicine, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China.
Development of novel Gd-based contrast agents for targeted magnetic resonance imaging (MRI) of liver cancer remains a great challenge. Herein we reported a novel Gd-based MRI contrast agent with improved relaxivity for specifically diagnosing liver cancer. This GSH-responsive macromolecular contrast agent (mCA), POLDGd, was prepared by RAFT polymerization, and its lactic acid moiety could precisely target the ASGP-R surface protein on liver cancer cells, whereas PODGd without the lactic acid moiety was prepared as a control.
View Article and Find Full Text PDFmBio
January 2025
Division of Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, USA.
Unlabelled: Streptolysin O (SLO) is a virulence determinant of group A (), the agent of streptococcal sore throat and severe invasive infections. SLO is a member of a family of bacterial pore-forming toxins known as cholesterol-dependent cytolysins, which require cell membrane cholesterol for pore formation. While cholesterol is essential for cytolytic activity, accumulating data suggest that cell surface glycans may also participate in the binding of SLO and other cholesterol-dependent cytolysins to host cells.
View Article and Find Full Text PDFPLoS Negl Trop Dis
January 2025
Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Australia.
More than 470 million people globally are infected with the hookworms Ancylostoma ceylanicum and Necator americanus, resulting in an annual loss of 2.1 to 4 million disability-adjusted-life-years. Current infection management approaches are limited by modest drug efficacy, the costs associated with frequent mass drug administration campaigns, and the risk of reinfection and burgeoning drug resistance.
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