title: Dicer has a crucial role in the early stage of adipocyte differentiation, but not in lipid synthesis, in 3T3-L1 cells.
abstract: Dicer is a rate-limiting enzyme for microRNA (miRNA) synthesis. To determine the effects of Dicer on adipogenesis, we performed stage-specific knockdown of Dicer using adenovirus encoding short-hairpin RNAi against Dicer in 3T3-L1 cells. When cells were infected with the adenovirus before induction of adipocyte differentiation, Dicer RNAi suppressed the gene expression of inducers of adipocyte differentiation such as PPARγ, C/EBPα, and FAS in 3T3-L1 cells during adipocyte differentiation. Concurrently, both adipocyte differentiation and cellular lipid accumulation were cancelled by Dicer RNAi when compared with control RNAi. Meanwhile, we addressed the roles of Dicer in lipid synthesis and accumulation in the final stages of differentiation. When the differentiated cells at day 4 after induction of differentiation were infected with adenovirus Dicer RNAi, cellular lipid accumulation was unchanged. Consistent with this, Dicer RNAi had no effects on the expression of genes related to cellular lipid accumulation, including PPARγ and FAS. Thus, Dicer controls proadipogenic genes such as C/EBPα and PPARγ in the early, but not in the late, stage of adipogenesis via regulation of miRNA synthesis.
authors.affiliation: Department of Internal Medicine (Metabolism and Endocrinology), Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Fujimoto
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Nakagawa
authors.forename: Akiko
authors.initials: A
authors.lastname: Shingyouchi
authors.forename: Naoko
authors.initials: N
authors.lastname: Tokushige
authors.forename: Noriko
authors.initials: N
authors.lastname: Nakanishi
authors.forename: Aoi
authors.initials: A
authors.lastname: Satoh
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsuzaka
authors.forename: Kiyo-aki
authors.initials: KA
authors.lastname: Ishii
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Iwasaki
authors.forename: Kazuto
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Yatoh
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Suzuki
authors.forename: Naoya
authors.initials: N
authors.lastname: Yahagi
authors.forename: Osamu
authors.initials: O
authors.lastname: Urayama
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Yamada
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Shimano
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology* / Q000378:metabolism*; D050156:Adipogenesis / Q000235:genetics*; D000818:Animals; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000235:genetics; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000502:physiology*; D005786:Gene Expression Regulation; D008055:Lipids / Q000096:biosynthesis; D051379:Mice; D047495:PPAR gamma / Q000235:genetics; D043244:Ribonuclease III / Q000235:genetics / Q000502:physiology*
chemical_list: D022782:CCAAT-Enhancer-Binding Protein-beta; C545013:Cebpb protein, mouse; D008055:Lipids; D047495:PPAR gamma; C509781:Dicer1 protein, mouse; D043244:Ribonuclease III; D053487:DEAD-box RNA Helicases