Evaluation of the available cholesterol concentration in the inner leaflet of the plasma membrane of mammalian cells
| Autor: | Shu-Lin Liu, Arthur Ralko, Pawanthi Buwaneka, Wonhwa Cho |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
0301 basic medicine
Phosphatidylinositol 4-phosphate perfringolysin O toxin 030204 cardiovascular system & hematology plasma membrane Biochemistry Green fluorescent protein EGFP enhanced green fluorescence protein PIP2 phosphoinositol-4 5-bisphosphate chemistry.chemical_compound 0302 clinical medicine Endocrinology cholesterol availability HUVEC human umbilical vein endothelial cell IPM inner leaflet of the plasma membrane ratiometric sensors HPAEC human pulmonary artery endothelial cell HLF human lung fibroblast quantitative fluorescence imaging POPE 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethano8lamine POPC 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine Osh4 Cell biology POPS 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoserine SAPC 1-stearoyl-2-arachidonoyl-sn-glycero-3-phosphocholine PM plasma membrane Human umbilical vein endothelial cell lipids (amino acids peptides and proteins) inner leaflet Research Article Cell signaling 25HC 25-hydroxycholesterol SPR surface plasmon resonance QD415-436 PI phosphatidylinositol 03 medical and health sciences FP fluorescence protein Phosphatidylinositol POPC PI(4)P phosphatidylinositol-4-phosphate Cholesterol Cell Membrane cholesterol Cell Biology MEF mouse embryonic fibroblast OPM outer leaflet of the plasma membrane Cytosol 030104 developmental biology chemistry GUV giant unilamellar vesicle cholesterol pools transbilayer asymmetry LUV large unilamellar vesicle SAG 1-stearoyl-2-arachidonoyl-sn-glycerol PFO perfringolysin O |
| Zdroj: | Journal of Lipid Research, Vol 62, Iss, Pp 100084-(2021) Journal of Lipid Research |
| ISSN: | 0022-2275 |
| Popis: | Cholesterol is an essential component of the mammalian plasma membrane involved in diverse cellular processes. Our recent quantitative imaging analysis using ratiometric cholesterol sensors showed that the available cholesterol concentration in the inner leaflet of the plasma membrane (IPM) is low in unstimulated cells and increased in a stimulus-specific manner to trigger cell signaling events. However, the transbilayer distribution of cholesterol in the plasma membrane of mammalian cells remains controversial. Here we report a systematic and rigorous evaluation of basal IPM cholesterol levels in a wide range of mammalian cells with different properties employing cholesterol sensors derived from the D4 domain of the Perfringolysin O toxin and a sterol-transfer protein, Osh4. Results consistently showed that, although basal IPM cholesterol levels vary significantly among cells, they remain significantly lower than cholesterol levels in the outer leaflets. We found that IPM cholesterol levels were particularly low in all tested primary cells. These results support the universality of the low basal IPM cholesterol concentration under physiological conditions. We also report here the presence of sequestered IPM cholesterol pools, which may become available to cytosolic proteins under certain physiological conditions. We hypothesize that these pools may partly account for the low basal level of available IPM cholesterol. In conclusion, we provide new experimental data that confirm the asymmetric transbilayer distribution of the plasma membrane cholesterol, which may contribute to regulation of various cellular signaling processes at the plasma membrane. |
| Databáze: | OpenAIRE |
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