title: A proteomic approach for identification of secreted proteins during the differentiation of 3T3-L1 preadipocytes to adipocytes.
abstract: We have undertaken a systematic proteomic approach to purify and identify secreted factors that are differentially expressed in preadipocytes versus adipocytes. Using one-dimensional gel electrophoresis combined with nanoelectrospray tandem mass spectrometry, proteins that were specifically secreted by 3T3-L1 preadipocytes or adipocytes were identified. In addition to a number of previously reported molecules that are up- or down-regulated during this differentiation process (adipsin, adipocyte complement-related protein 30 kDa, complement C3, and fibronectin), we identified four secreted molecules that have not been shown previously to be expressed differentially during the process of adipogenesis. Pigment epithelium-derived factor, a soluble molecule with potent antiangiogenic properties, was found to be highly secreted by preadipocytes but not adipocytes. Conversely, we found hippocampal cholinergic neurostimulating peptide, neutrophil gelatinase-associated lipocalin, and haptoglobin to be expressed highly by mature adipocytes. We also used liquid chromatography-based separation followed by automated tandem mass spectrometry to identify proteins secreted by mature adipocytes. Several additional secreted proteins including resistin, secreted acidic cysteine-rich glycoprotein/osteonectin, stromal cell-derived factor-1, cystatin C, gelsolin, and matrix metalloprotease-2 were identified by this method. To our knowledge, this is the first study to identify several novel secreted proteins by adipocytes by a proteomic approach using mass spectrometry.
authors.affiliation: Center for Experimental Bioinformatics, University of Southern Denmark, Odense M, DK-5230 Denmark.
authors.forename: Irina
authors.initials: I
authors.lastname: Kratchmarova
authors.forename: Dario E
authors.initials: DE
authors.lastname: Kalume
authors.forename: Blagoy
authors.initials: B
authors.lastname: Blagoev
authors.forename: Philipp E
authors.initials: PE
authors.lastname: Scherer
authors.forename: Alexandre V
authors.initials: AV
authors.lastname: Podtelejnikov
authors.forename: Henrik
authors.initials: H
authors.lastname: Molina
authors.forename: Perry E
authors.initials: PE
authors.lastname: Bickel
authors.forename: Jens S
authors.initials: JS
authors.lastname: Andersen
authors.forename: Minerva M
authors.initials: MM
authors.lastname: Fernandez
authors.forename: Jacob
authors.initials: J
authors.lastname: Bunkenborg
authors.forename: Peter
authors.initials: P
authors.lastname: Roepstorff
authors.forename: Karsten
authors.initials: K
authors.lastname: Kristiansen
authors.forename: Harvey F
authors.initials: HF
authors.lastname: Lodish
authors.forename: Matthias
authors.initials: M
authors.lastname: Mann
authors.forename: Akhilesh
authors.initials: A
authors.lastname: Pandey
mesh_terms: D016475:3T3 Cells; D000209:Acute-Phase Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017667:Adipocytes / Q000166:cytology* / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation; D005136:Eye Proteins; D015870:Gene Expression; D006242:Haptoglobins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D000071068:Lipocalin-2; D054834:Lipocalins; D051379:Mice; D009414:Nerve Growth Factors; D009479:Neuropeptides / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D015513:Oncogene Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D011506:Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D020543:Proteome / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D015843:Serpins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D000099174:Pigment Epithelium-Derived Factor
chemical_list: D000209:Acute-Phase Proteins; D005136:Eye Proteins; D006242:Haptoglobins; D000071068:Lipocalin-2; D054834:Lipocalins; D009414:Nerve Growth Factors; D009479:Neuropeptides; D015513:Oncogene Proteins; D011506:Proteins; D020543:Proteome; D015843:Serpins; D000099174:Pigment Epithelium-Derived Factor; C071332:Lcn2 protein, mouse; C075274:hippocampal cholinergic neurostimulating peptide