title: TonEBP suppresses adipocyte differentiation via modulation of early signaling in 3T3-L1 cells.
abstract: TonEBP belongs to the Rel family of transcription factors and plays important roles in inflammation as well as kidney homeostasis. Recent studies suggest that TonEBP expression is also involved in differentiation of several cell types such as myocytes, chondrocytes, and osteocytes. In this study, we investigated the roles of TonEBP during adipocyte differentiation in 3T3-L1 cells. TonEBP mRNA and protein expression was dramatically reduced during adipocyte differentiation. Sustained expression of TonEBP using an adenovirus suppressed the formation of lipid droplets as well as the expression of FABP4, a marker of differentiated adipocytes. TonEBP also inhibited the expression of PPARγ, a known master regulator of adipocytes. RNAi-mediated knock down of TonEBP promoted adipocyte differentiation. However, overexpression of TonEBP did not affect adipogenesis after the initiation of differentiation. Furthermore, TonEBP expression suppressed mitotic clonal expansion and insulin signaling, which are required early for adipocyte differentiation of 3T3-L1 cells. These results suggest that TonEBP may be an important regulatory factor in the early phase of adipocyte differentiation.
authors.affiliation: Department of Physiology, Chungnam National University School of Medicine, Daejeon 35015, Korea.
authors.forename: Soo Jin
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Physiology, Chungnam National University School of Medicine, Daejeon 35015, Korea.
authors.forename: Taehee
authors.initials: T
authors.lastname: Kim
authors.affiliation: Department of Physiology, Chungnam National University School of Medicine, Daejeon 35015, Korea.
authors.forename: Han Na
authors.initials: HN
authors.lastname: Choi
authors.affiliation: Department of Physiology, Chungnam National University School of Medicine, Daejeon 35015, Korea.
authors.forename: Eun Jung
authors.initials: EJ
authors.lastname: Cho
authors.affiliation: Department of Physiology, Chungnam National University School of Medicine, Daejeon 35015, Korea.
authors.forename: Jin Bong
authors.initials: JB
authors.lastname: Park
authors.affiliation: Department of Physiology, Chungnam National University School of Medicine, Daejeon 35015, Korea.
authors.forename: Byeong Hwa
authors.initials: BH
authors.lastname: Jeon
authors.affiliation: Department of Physiology, Chungnam National University School of Medicine, Daejeon 35015, Korea.
authors.forename: Sang Do
authors.initials: SD
authors.lastname: Lee
keywords: Adipogenesis; Akt; Insulin; TonEBP