title: Removal of serum factors by charcoal treatment promotes adipogenesis via a MAPK-dependent pathway.
abstract: In vitro differentiation of the progenitor cells or preadipocytes into adipocytes is usually achieved by adding an adipogenic mixture (isobutylmethylxanthine, dexamethasone, and insulin, IDI) to medium supplemented with fetal bovine serum (FBS). To study the effects of steroid hormones in vitro, endogenous hormones, growth factors and cytokines are removed by charcoal stripping of serum. However, the effects of charcoal-stripped serum (CS-FBS) per se on adipogenesis have been ignored. Here, we showed that alkaline phosphate activity and nodule formation of osteoprogenitor KS483 cells were lower in CS-FBS than in FBS. Concurrently, abundant amounts of adipocytes were only observed in KS483 cells cultured with CS-FBS, irrespective of the brands of serum used. Inhibition of the p42/44 MAPK pathway by its specific inhibitor PD98059 increased adipogenesis of KS483 cells with FBS, whereas activation of this signalling pathway by EGF blocked adipogenesis of these cells with CS-FBS. Furthermore, the p42/44 MAPK phosphorylation of KS483 cells cultured with CS-FBS was decreased compared with FBS. We concluded that charcoal-stripping of serum removed stimulators of the MAPK signalling pathway and in turn led to downregulation of osteogenesis and upregulation of adipogenesis. Interestingly, the adipogenic mixture IDI stimulated adipogenesis of KS483 cells cultured with CS-FBS, but not with FBS. Furthermore, differential effects of genistein on adipogenesis were observed in KS483 cells cultured with FBS or CS-FBS in combination with IDI. Our results showed that charcoal stripping of serum affected the commitment of KS483 cells and therefore differentially regulated adipogenesis influenced by IDI alone and in combination with genistein.
authors.affiliation: Department of Endocrinology and Metabolic Diseases, Leiden University Medical Center, Leiden, The Netherlands. zcdang@yahoo.com
authors.forename: Z C
authors.initials: ZC
authors.lastname: Dang
authors.forename: C W G M
authors.initials: CW
authors.lastname: Lowik
mesh_terms: D017667:Adipocytes / Q000502:physiology*; D000818:Animals; D001685:Biological Factors / Q000737:chemistry / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D006801:Humans; D008055:Lipids / Q000096:biosynthesis*; D020935:MAP Kinase Signaling System / Q000502:physiology*; D010006:Osteoblasts / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology; D010949:Plasma / Q000737:chemistry / Q000502:physiology
chemical_list: D001685:Biological Factors; D008055:Lipids
references.citation: J Bone Miner Res. 1999 May;14(5):700-9
references.pmid: 10320518
references.citation: J Biol Chem. 1997 Feb 21;272(8):5128-32
references.pmid: 9030579
references.citation: J Cell Physiol. 1990 Dec;145(3):587-95
references.pmid: 1703173
references.citation: Science. 1996 Dec 20;274(5295):2100-3
references.pmid: 8953045
references.citation: J Cell Physiol. 1994 Mar;158(3):467-75
references.pmid: 8126070
references.citation: Genes Dev. 2002 Jan 1;16(1):22-6
references.pmid: 11782441
references.citation: J Biol Chem. 1997 Apr 18;272(16):10811-6
references.pmid: 9099735
references.citation: J Cell Biol. 1998 Jul 13;142(1):295-305
references.pmid: 9660882
references.citation: J Biol Chem. 1998 May 8;273(19):11685-94
references.pmid: 9565589
references.citation: Exp Hematol. 1987 Mar;15(3):234-8
references.pmid: 2434353
references.citation: J Cell Physiol. 1991 Jun;147(3):505-13
references.pmid: 1648567
references.citation: J Bone Miner Res. 1998 Mar;13(3):371-82
references.pmid: 9525337
references.citation: J Biol Chem. 2000 Feb 11;275(6):4453-9
references.pmid: 10660618
references.citation: Genes Dev. 2002 Jan 1;16(1):27-32
references.pmid: 11782442
references.citation: Physiol Rev. 1998 Jul;78(3):783-809
references.pmid: 9674695
references.citation: J Biol Chem. 1999 Nov 5;274(45):32159-66
references.pmid: 10542252
references.citation: Curr Opin Genet Dev. 1997 Oct;7(5):603-8
references.pmid: 9388775
references.citation: Biochem J. 2002 Oct 1;367 (Pt 1):203-8
references.pmid: 12095417
references.citation: J Bone Miner Res. 2002 Mar;17 (3):394-405
references.pmid: 11878304
references.citation: J Biol Chem. 1997 Feb 7;272(6):3406-10
references.pmid: 9013583
references.citation: Annu Rev Biochem. 2001;70:341-67
references.pmid: 11395411
references.citation: Curr Opin Cell Biol. 1998 Apr;10(2):165-73
references.pmid: 9561840
references.citation: Endocrinology. 2000 May;141(5):1667-74
references.pmid: 10803575
references.citation: J Biol Chem. 2003 Jan 10;278(2):962-7
references.pmid: 12421816
references.citation: Genes Dev. 2000 Jun 1;14(11):1293-307
references.pmid: 10837022
references.citation: J Cell Sci. 1992 Jun;102 ( Pt 2):341-51
references.pmid: 1400636
references.citation: Eur J Clin Invest. 1995 Feb;25(2):90-6
references.pmid: 7737268
references.citation: Annu Rev Nutr. 2000;20:535-59
references.pmid: 10940345
references.citation: J Bone Miner Res. 1998 Jan;13(1):96-106
references.pmid: 9443795
references.citation: J Biol Chem. 2001 Apr 27;276(17):14443-50
references.pmid: 11278600
references.citation: Science. 1999 Apr 2;284(5411):143-7
references.pmid: 10102814
references.citation: Mol Pharmacol. 1996 Nov;50(5):1087-94
references.pmid: 8913339
references.citation: Cancer Res. 1990 Dec 15;50(24):7806-10
references.pmid: 2253223
references.citation: Genes Dev. 2002 Jan 1;16(1):1-5
references.pmid: 11782439
references.citation: Anal Biochem. 1980 Mar 1;102(2):344-52
references.pmid: 6158890
references.citation: J Biol Chem. 2001 Apr 27;276(17):14133-8
references.pmid: 11278824
references.citation: J Bone Miner Res. 1999 Dec;14(12):2067-78
references.pmid: 10620066
references.citation: Bone. 1996 Nov;19(5):429-36
references.pmid: 8922640
references.citation: Endocrinology. 2001 Nov;142(11):4900-9
references.pmid: 11606458