Cell density-induced changes in lipid composition and intracellular trafficking.
Cell density is one of the extrinsic factors to which cells adapt their physiology when grown in culture. However, little is known about the molecular changes which occur during cell growth and how cellular responses are then modulated. In many cases, inhibitors, drugs or growth factors used for in vitro studies change the rate of cell proliferation, resulting in different cell densities in control and treated samples. Therefore, for a comprehensive data analysis, it is essential to understand the implications of cell density on the molecular level. In this study, we have investigated how lipid composition changes during cell growth, and the consequences it has for transport of Shiga toxin. By quantifying 308 individual lipid species from 17 different lipid classes, we have found that the levels and species distribution of several lipids change during cell growth, with the major changes observed for diacylglycerols, phosphatidic acids, cholesterol esters, and lysophosphatidylethanolamines. In addition, there is a reduced binding and retrograde transport of Shiga toxin in high density cells which lead to reduced intoxication by the toxin. In conclusion, our data provide novel information on how lipid composition changes during cell growth in culture, and how these changes can modulate intracellular trafficking.
Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Montebello, 0379, Oslo, Norway.
Simona
S
Kavaliauskiene
Carl-Martin
CM
Nymark
Jonas
J
Bergan
Roger
R
Simm
Tuulia
T
Sylvänne
Helena
H
Simolin
Kim
K
Ekroos
Tore
T
Skotland
Kirsten
K
Sandvig
D002452:Cell Count; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D002784:Cholesterol / Q000378:metabolism; D004075:Diglycerides / Q000378:metabolism; D005915:Globosides / Q000378:metabolism; D006028:Glycosphingolipids / Q000378:metabolism; D006367:HeLa Cells; D056945:Hep G2 Cells; D006801:Humans; D050356:Lipid Metabolism; D008246:Lysophospholipids / Q000378:metabolism; D010712:Phosphatidic Acids / Q000378:metabolism; D021381:Protein Transport; D022621:Shiga Toxin / Q000378:metabolism; D050827:Syntaxin 1 / Q000235:genetics / Q000378:metabolism*; D014281:Trihexosylceramides / Q000378:metabolism
D004075:Diglycerides; D005915:Globosides; D006028:Glycosphingolipids; D008246:Lysophospholipids; D010712:Phosphatidic Acids; C494212:STX1A protein, human; D050827:Syntaxin 1; D014281:Trihexosylceramides; C514780:globotrihexosylceramide; C008301:lysophosphatidylethanolamine; D022621:Shiga Toxin; D002784:Cholesterol