title: FSP27 contributes to efficient energy storage in murine white adipocytes by promoting the formation of unilocular lipid droplets.
abstract: White adipocytes are unique in that they contain large unilocular lipid droplets that occupy most of the cytoplasm. To identify genes involved in the maintenance of mature adipocytes, we expressed dominant-negative PPARgamma in 3T3-L1 cells and performed a microarray screen. The fat-specific protein of 27 kDa (FSP27) was strongly downregulated in this context. FSP27 expression correlated with induction of differentiation in cultured preadipocytes, and the protein localized to lipid droplets in murine white adipocytes in vivo. Ablation of FSP27 in mice resulted in the formation of multilocular lipid droplets in these cells. Furthermore, FSP27-deficient mice were protected from diet-induced obesity and insulin resistance and displayed an increased metabolic rate due to increased mitochondrial biogenesis in white adipose tissue (WAT). Depletion of FSP27 by siRNA in murine cultured white adipocytes resulted in the formation of numerous small lipid droplets, increased lipolysis, and decreased triacylglycerol storage, while expression of FSP27 in COS cells promoted the formation of large lipid droplets. Our results suggest that FSP27 contributes to efficient energy storage in WAT by promoting the formation of unilocular lipid droplets, thereby restricting lipolysis. In addition, we found that the nature of lipid accumulation in WAT appears to be associated with maintenance of energy balance and insulin sensitivity.
authors.affiliation: Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Naonobu
authors.initials: N
authors.lastname: Nishino
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Tamori
authors.forename: Sanshiro
authors.initials: S
authors.lastname: Tateya
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kawaguchi
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Shibakusa
authors.forename: Wataru
authors.initials: W
authors.lastname: Mizunoya
authors.forename: Kazuo
authors.initials: K
authors.lastname: Inoue
authors.forename: Riko
authors.initials: R
authors.lastname: Kitazawa
authors.forename: Sohei
authors.initials: S
authors.lastname: Kitazawa
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Matsuki
authors.forename: Ryuji
authors.initials: R
authors.lastname: Hiramatsu
authors.forename: Satoru
authors.initials: S
authors.lastname: Masubuchi
authors.forename: Asako
authors.initials: A
authors.lastname: Omachi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kimura
authors.forename: Masayuki
authors.initials: M
authors.lastname: Saito
authors.forename: Taku
authors.initials: T
authors.lastname: Amo
authors.forename: Shigeo
authors.initials: S
authors.lastname: Ohta
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Osumi
authors.forename: Jinglei
authors.initials: J
authors.lastname: Cheng
authors.forename: Toyoshi
authors.initials: T
authors.lastname: Fujimoto
authors.forename: Harumi
authors.initials: H
authors.lastname: Nakao
authors.forename: Kazuki
authors.initials: K
authors.lastname: Nakao
authors.forename: Atsu
authors.initials: A
authors.lastname: Aiba
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Okamura
authors.forename: Tohru
authors.initials: T
authors.lastname: Fushiki
authors.forename: Masato
authors.initials: M
authors.lastname: Kasuga
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology / Q000378:metabolism*; D002001:Adipose Tissue, Brown / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D052436:Adipose Tissue, White / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D000818:Animals; D019556:COS Cells; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D003433:Crosses, Genetic; D004734:Energy Metabolism / Q000502:physiology*; D005786:Gene Expression Regulation; D006579:Heterozygote; D008066:Lipolysis / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008817:Mice, Mutant Strains; D008970:Molecular Weight; D011506:Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism
chemical_list: D011506:Proteins; D034741:RNA, Small Interfering; C525805:fat-specific protein 27, mouse