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SHR Neuro Krebs Kardio Lipid

Nusshold, C; Uellen, A; Bernhart, E; Hammer, A; Damm, S; Wintersperger, A; Reicher, H; Hermetter, A; Malle, E; Sattler, W.
Endocytosis and intracellular processing of BODIPY-sphingomyelin by murine CATH.a neurons.
Biochim Biophys Acta. 2013; 1831(12):1665-1678 [OPEN ACCESS]
Web of Science PubMed PUBMED Central FullText FullText_MUG

 

Autor/innen der Med Uni Graz:
Bernhart Eva Maria
Damm Sabine
Hammer Astrid
Malle Ernst
Nusshold Christoph
Reicher Helga
Sattler Wolfgang
Üllen Andreas
Wintersperger Andrea
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Number of Figures: 10
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Abstract:
Neuronal sphingolipids (SL) play important roles during axonal extension, neurotrophic receptor signaling and neurotransmitter release. Many of these signaling pathways depend on the presence of specialized membrane microdomains termed lipid rafts. Sphingomyelin (SM), one of the main raft constituents, can be formed de novo or supplied from exogenous sources. The present study aimed to characterize fluorescently-labeled SL turnover in a murine neuronal cell line (CATH.a). Our results demonstrate that at 4°C exogenously added BODIPY-SM accumulates exclusively at the plasma membrane. Treatment of cells with bacterial sphingomyelinase (SMase) and back-exchange experiments revealed that 55-67% of BODIPY-SM resides in the outer leaflet of the plasma membrane. Endocytosis of BODIPY-SM occurs via caveolae with part of internalized BODIPY-fluorescence ending up in the Golgi and the ER. Following endocytosis BODIPY-SM undergoes hydrolysis, a reaction substantially faster than BODIPY-SM synthesis from BODIPY-ceramide. RNAi demonstrated that both, acid (a)SMase and neutral (n)SMases contribute to BODIPY-SM hydrolysis. Finally, high-density lipoprotein (HDL)-associated BODIPY-SM was efficiently taken up by CATH.a cells. Our findings indicate that endocytosis of exogenous SM occurs almost exclusively via caveolin-dependent pathways, that both, a- and nSMases equally contribute to neuronal SM turnover and that HDL-like particles might represent physiological SM carriers/donors in the brain.
Find related publications in this database (using NLM MeSH Indexing)
Animals -
Boron Compounds -
Caveolins - genetics
Cell Line -
Endocytosis -
Endoplasmic Reticulum - drug effects
Fluorescent Dyes -
Gene Expression Regulation -
Golgi Apparatus - drug effects
Hydrolysis -
Isoenzymes - antagonists & inhibitors
Lipoproteins, HDL - metabolism
Membrane Microdomains - drug effects
Mice -
Neurons - cytology
RNA, Small Interfering - genetics
Signal Transduction -
Sphingomyelin Phosphodiesterase - antagonists & inhibitors
Sphingomyelins - metabolism
Temperature -

Find related publications in this database (Keywords)
Sphingomyelinase
High density lipoprotein
Caveolar uptake
Endocytosis
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