Unlabelled: Within cellular membranes, sphingomyelin is associated with cholesterol and this complex facilitates homeostatic regulation of membrane viscosity. Acute cholesterol depletion increases the synthesis of very-long-chain (VLC) sphingomyelin, but a link between lipid sensing and sphingolipid synthesis is lacking. Using sphingolipid metabolic flux analysis, we observed that VLC-ceramide, the precursor to VLC complex sphingolipids that are produced in the Golgi apparatus, was rapidly consumed after cholesterol depletion, while synthesis of long-chain sphingolipids was unaffected. Sphingolipid trafficking assays showed that cholesterol depletion enhances VLC-Ceramide trafficking from the endoplasmic reticulum to the Golgi apparatus. Changes in the sizes of coatomer II ER exit sites were correlated with increased VLC-Ceramide trafficking and concomitant increase in sphingomyelin. Depletion of Sec16A, a component of the COPII network, abolished VLC-SM synthesis. This study reveals ER-to-Golgi trafficking of VLC-Ceramide as a key regulatory node in organelle membrane homeostasis pathways.
Summary: In cellular membranes, sphingomyelin is associated with cholesterol. Metabolic flux analysis of sphingolipid metabolism showed that synthesis rate of sphingomyelin, but not ceramide, was increased after depletion of cholesterol due increased rate of COPII-dependent ER-to-Golgi transport of ceramide.
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http://dx.doi.org/10.1101/2025.02.12.637879 | DOI Listing |
Mol Pharm
March 2025
Department of Pharmaceutical Technology, Faculty of Science, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 8, Tuebingen 72076, Germany.
The stratum corneum (SC) lipids provide the main barrier of the skin against the environment. Ceramides make up about half of the lipids by weight and are thus of particular interest. Emulsifiers are used in a multitude of topical formulations, e.
View Article and Find Full Text PDFCardiovasc Endocrinol Metab
June 2025
Department of Medical Sciences, Faculty of Medicine, Qom Medical Sciences, Islamic Azad University, Qom, Iran.
Background: Statins are prescribed to manage hypercholesterolemia. While effective, these medications are associated with adverse effects, particularly myopathy. Cholesterol is essential for muscle function, and its depletion - especially by lipophilic statins - may contribute to muscle damage.
View Article and Find Full Text PDFPart Fibre Toxicol
March 2025
IUF - Leibniz Research Institute for Environmental Medicine, Auf'm Hennekamp 50, 40225, Düsseldorf, Germany.
Background: Inhalation of combustion-derived nanoparticles may contribute to the development or exacerbation of inflammatory lung diseases by direct interaction with neutrophilic granulocytes. Earlier studies have shown that exposure of human neutrophils to carbon nanoparticles ex vivo causes a prolongation of cellular life by the reduction of apoptosis rates. Accordingly, reduced neutrophil apoptosis rates were observed in neutrophils from bronchoalveolar lavages from carbon nanoparticle-exposed animals.
View Article and Find Full Text PDFNat Commun
March 2025
Strait Laboratory of Flexible Electronics (SLoFE), Fujian Key Laboratory of Flexible Electronics, Key Laboratory of Opto-Electronic Science and Technology for Medicine of Ministry of Education, College of Photonic and Electronic Engineering, Strait Institute of Flexible Electronics (SIFE, Future Technologies), Fujian Normal University, Fuzhou, Fujian, China.
Despite the tremendous therapeutic promise of activating stimulators of interferon genes (STING) enable to prime robust de novo T-cell responses, biomechanics-mediated immune inhibitory pathways hinder the cytotoxicity of T cells against tumor cells. Blocking cancer cell biomechanics-mediated evasion provides a feasible strategy for augmenting STING activation-mediated anti-tumor therapeutic efficacy. Here, we fabricate a redox-responsive Methyl-β-cyclodextrin (MeβCD)-based supramolecular polyrotaxanes (MSPs), where the amphiphilic diselenide-bridged axle polymer loads MeβCD by the host-guest interaction and end-caping with two near-infrared (NIR) fluorescence probes IR783.
View Article and Find Full Text PDFIn quest of a new working design for a photostable lipid-droplets (LDs) bioimaging probe, we herein unveil and demonstrate a twisted donor(naphthalene)-π-acceptor(dicyano) architecture linked with oxo/thioether functionality, where the probes' emission, hydrophobicity, cytotoxicity, and cell permeability are altered by replacing the present chalcogen/s. In this class of molecules, an "oxanthrene"-based compound, "", was realized as the noncytotoxic and cell-permeable probe, displaying intense fluorescence in a nonpolar solvent, aggregates, and viscous medium. Time-dependent density functional theory (TD-DFT) investigations revealed that holds a favorable extent of excited-state planarity to bring out considerable emission only in a nonpolar solvent, resulting in polarity-dependent emission.
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