title: Changes in the phospholipid fatty acid composition of the lipid droplet during the differentiation of 3T3-L1 adipocytes.
abstract: Lipid droplets (LDs) are independent organelles in adipocytes that are composed of a lipid ester core surrounded by a phospholipid monolayer. The fatty acid composition of the phospholipid monolayer should determine the metabolism and dynamics of LDs. In this study, we examined the fatty acid composition of phospholipid monolayer in LDs during the differentiation of 3T3-L1 adipocytes. The levels of saturated fatty acids (SFAs), such as 16:0 and 18:0, in phosphatidylcholine (PC) and phosphatidylethanolamine (PE) of LDs decreased during differentiation. In contrast, the levels of monounsaturated fatty acids (MUFAs) such as 16:1n-7 and 18:1n-9 in PC and PE of LDs and the level of polyunsaturated fatty acids (PUFAs) such as 20:3n-6, 20:4n-6 and 22:6n-3 in PE of LDs increased during differentiation. These results suggest that the phospholipid monolayer in mature LDs is more fluid than that in nascent LDs. The fatty acid compositions of the LD monolayer were different from those of the microsome bilayer in the early stage of differentiation, but similar to those of the microsome bilayer in the late stage of differentiation. These data provide evidence that biophysical properties of the phospholipid monolayer in LDs change during adipocyte differentiation.
authors.affiliation: Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo 112-8610, Japan.
authors.forename: Kotoko
authors.initials: K
authors.lastname: Arisawa
authors.forename: Ikuyo
authors.initials: I
authors.lastname: Ichi
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Yasukawa
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Sone
authors.forename: Yoko
authors.initials: Y
authors.lastname: Fujiwara
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D002855:Chromatography, Thin Layer; D005227:Fatty Acids / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D050356:Lipid Metabolism; D051379:Mice; D015388:Organelles / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism
chemical_list: D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; C483858:phosphatidylethanolamine
keywords: adipocyte; fatty acid; lipid droplet; phospholipid