title: γ-Oryzanol Enhances Adipocyte Differentiation and Glucose Uptake.
abstract: Recent studies show that brown rice improves glucose intolerance and potentially the risk of diabetes, although the underlying molecular mechanisms remain unclear. One of the phytochemicals found in high concentration in brown rice is γ-oryzanol (Orz), a group of ferulic acid esters of phytosterols and triterpene alcohols. Here, we found that Orz stimulated differentiation of 3T3-L1 preadipocytes and increased the protein expression of adipogenic marker genes such as peroxisome proliferator-activated receptor gamma (PPAR-γ) and CCAAT/enhanced binding protein alpha (C/EBPα). Moreover, Orz significantly increased the glucose uptake in insulin-resistant cells and translocation of glucose transporter type 4 (GLUT4) from the cytosol to the cell surface. To investigate the mechanism by which Orz stimulated cell differentiation, we examined its effects on cellular signaling of the mammalian target of rapamycin complex 1 (mTORC1), a central mediator of cellular growth and proliferation. The Orz treatment increased mTORC1 kinase activity based on phosphorylation of 70-kDa ribosomal S6 kinase 1 (S6K1). The effect of Orz on adipocyte differentiation was dependent on mTORC1 activity because rapamycin blocks cell differentiation in Orz-treated cells. Collectively, our results indicate that Orz stimulates adipocyte differentiation, enhances glucose uptake, and may be associated with cellular signaling mediated by PPAR-γ and mTORC1.
authors.affiliation: Department of Food Biotechnology, Korea University of Science and Technology, 1201 Anyangpangyo-ro, Bundang-ku, Seongnam 463-746, Korea. chjung@kfri.re.kr.|Metabolic Mechanism Research Group, Korea Food Research Institute, 1201 Anyangpangyo-ro, Bundang-ku, Seongnam 463-746, Korea. chjung@kfri.re.kr.
authors.forename: Chang Hwa
authors.initials: CH
authors.lastname: Jung
authors.affiliation: Department of Food Biotechnology, Korea University of Science and Technology, 1201 Anyangpangyo-ro, Bundang-ku, Seongnam 463-746, Korea. dlekgp26@nate.com.
authors.forename: Da-Hye
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Food Biotechnology, Korea University of Science and Technology, 1201 Anyangpangyo-ro, Bundang-ku, Seongnam 463-746, Korea. jyan@kfri.re.kr.|Metabolic Mechanism Research Group, Korea Food Research Institute, 1201 Anyangpangyo-ro, Bundang-ku, Seongnam 463-746, Korea. jyan@kfri.re.kr.
authors.forename: Jiyun
authors.initials: J
authors.lastname: Ahn
authors.affiliation: Metabolic Mechanism Research Group, Korea Food Research Institute, 1201 Anyangpangyo-ro, Bundang-ku, Seongnam 463-746, Korea. Lee.Hyun-jung@kfri.re.kr.
authors.forename: Hyunjung
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Food Biotechnology, Korea University of Science and Technology, 1201 Anyangpangyo-ro, Bundang-ku, Seongnam 463-746, Korea. kfri2@daum.net.
authors.forename: Won Hee
authors.initials: WH
authors.lastname: Choi
authors.affiliation: Metabolic Mechanism Research Group, Korea Food Research Institute, 1201 Anyangpangyo-ro, Bundang-ku, Seongnam 463-746, Korea. jyj616@kfri.re.kr.
authors.forename: Young Jin
authors.initials: YJ
authors.lastname: Jang
authors.affiliation: Department of Food Biotechnology, Korea University of Science and Technology, 1201 Anyangpangyo-ro, Bundang-ku, Seongnam 463-746, Korea. tyhap@kfri.re.kr.|Metabolic Mechanism Research Group, Korea Food Research Institute, 1201 Anyangpangyo-ro, Bundang-ku, Seongnam 463-746, Korea. tyhap@kfri.re.kr.
authors.forename: Tae-Youl
authors.initials: TY
authors.lastname: Ha
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects*; D000818:Animals; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D005786:Gene Expression Regulation; D005947:Glucose / Q000493:pharmacokinetics*; D051275:Glucose Transporter Type 4 / Q000235:genetics / Q000378:metabolism; D007333:Insulin Resistance; D000076222:Mechanistic Target of Rapamycin Complex 1; D051379:Mice; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism; D012275:Oryza / Q000737:chemistry; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism; D010666:Phenylpropionates / Q000494:pharmacology*; D010766:Phosphorylation; D064209:Phytochemicals / Q000494:pharmacology; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D000067348:Whole Grains / Q000737:chemistry
chemical_list: D022762:CCAAT-Enhancer-Binding Proteins; C530718:CEBPA protein, mouse; D051275:Glucose Transporter Type 4; D046912:Multiprotein Complexes; D047495:PPAR gamma; D010666:Phenylpropionates; D064209:Phytochemicals; C495693:Slc2a4 protein, mouse; D000076222:Mechanistic Target of Rapamycin Complex 1; D038744:Ribosomal Protein S6 Kinases, 90-kDa; C512964:Rps6ka1 protein, mouse; D058570:TOR Serine-Threonine Kinases; D005947:Glucose; C013172:gamma-oryzanol
keywords: 3T3-L1; PPAR-γ; adipocyte; glucose uptake; mTORC1; γ-oryzanol