title: Exogenous Sodium Pyruvate Stimulates Adipogenesis of 3T3-L1 Cells.
abstract: We investigated the effects of exogenous sodium pyruvate (SP) on adipocyte differentiation, lipid accumulation, and the mRNA expression levels of adipogenesis-related genes in 3T3-L1 pre-adipocytes. Differentiation of pre-adipocytes was induced by MDI (3-isobutyl-1-methylxanthine: IBMX, dexamethasone: DEX, and insulin), in the presence or absence of SP. Adipogenesis was stimulated by SP in a concentration-dependent manner. SP also induced the expression of genes encoding aP2, GLUT4, and adiponectin, but had no effect on cell proliferation. Exogenous glucose did not promote adipogenesis or lipid accumulation. 2-deoxy-D-glucose inhibited adipogenesis initiated by MDI, but failed to influence the effects of SP on adipogenesis, whereas 3-bromopyruvate inhibited adipogenesis regardless of whether SP was present. The pro-adipogenic properties of SP were limited to the early events of adipogenesis. To determine whether SP mimics the adipogenic action of dexamethasone or insulin, we examined the effects of SP on adipogenesis with combinations of IBMX, DEX, and insulin. SP did not improve incomplete lipid accumulation observed in cells grown under IBMX-, DEX-, or insulin-free conditions. Insulin-stimulated ERK1/2 phosphorylation was diminished by SP, while phosphorylation of Akt was increased, correlating with increased glucose uptake in response to insulin. We also observed that SP stimulated immediate early expression of C/EBPβ and C/EBPδ. The PPARγ antagonist GW9662 inhibited adipogenesis. Our findings highlight the adipogenic function of exogenous SP by stimulating early events of adipogenesis.
authors.affiliation: Department of Physiology and Biophysics, College of Medicine, Inha University, Incheon, Korea.
authors.forename: Ji-Sun
authors.initials: JS
authors.lastname: Hwang
authors.affiliation: Department of Physiology and Biophysics, College of Medicine, Inha University, Incheon, Korea.
authors.forename: Song-Yi
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Physiology and Biophysics, College of Medicine, Inha University, Incheon, Korea.
authors.forename: Eun-Hye
authors.initials: EH
authors.lastname: Jung
authors.affiliation: Department of Physiology and Biophysics, College of Medicine, Inha University, Incheon, Korea.
authors.forename: Mi-Youn
authors.initials: MY
authors.lastname: Kwon
authors.affiliation: Department of Physiology and Biophysics, College of Medicine, Inha University, Incheon, Korea.
authors.forename: Kyoung-Hong
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Inha University, Incheon, Korea.
authors.forename: Hyeongjin
authors.initials: H
authors.lastname: Cho
authors.affiliation: Department of Physiology and Biophysics, College of Medicine, Inha University, Incheon, Korea.
authors.forename: Inn-Oc
authors.initials: IO
authors.lastname: Han
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D041721:3T3-L1 Cells; D050156:Adipogenesis / Q000187:drug effects*; D052242:Adiponectin / Q000378:metabolism; D000818:Animals; D003847:Deoxyglucose / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D051275:Glucose Transporter Type 4 / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology; D051379:Mice; D011773:Pyruvates / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D052242:Adiponectin; D051275:Glucose Transporter Type 4; D007328:Insulin; D011773:Pyruvates; D003907:Dexamethasone; D003847:Deoxyglucose; D015056:1-Methyl-3-isobutylxanthine
keywords: 3T3-L1; ADIPOGENESIS; SODIUM PYRUVATE