title: Proteomic identification of differently expressed proteins responsible for osteoblast differentiation from human mesenchymal stem cells.
abstract: Human mesenchymal stem cells (hMSC) are a population of multipotent cells that can differentiate into osteoblasts, chondrocytes, adipocytes, and other cells. The exact mechanism governing the differentiation of hMSC into osteoblasts remains largely unknown. Here, we analyzed protein expression profiles of undifferentiated as well as osteogenic induced hMSC using 2-D gel electrophoresis (2-DE), mass spectrometry (MS), and peptide mass fingerprinting (PMF) to investigate the early gene expression in osteoblast differentiation. We have generated proteome maps of undifferentiated hMSC and osteogenic induced hMSC on day 3 and day 7. 2-DE revealed 102 spots with at least 2.0-fold changes in expression and 52 differently expressed proteins were successfully identified by MALDI-TOF-MS. These proteins were classified into 7 functional categories: metabolism, signal transduction, transcription, calcium-binding protein, protein degradation, protein folding and others. The expression of some identified proteins was confirmed by further RT-PCR analyses. This study clarifies the global proteome during osteoblast differentiation. Our results will play an important role in better elucidating the underlying molecular mechanism in hMSC differentiation into osteoblasts.
authors.affiliation: Center for Stem Cell Biology and Tissue Engineering, Sun Yat-sen University, No. 74, Zhongshan Road 2, Guangzhou 510080, China.
authors.forename: Ai-Xia
authors.initials: AX
authors.lastname: Zhang
authors.forename: Wei-Hua
authors.initials: WH
authors.lastname: Yu
authors.forename: Bao-Feng
authors.initials: BF
authors.lastname: Ma
authors.forename: Xin-Bing
authors.initials: XB
authors.lastname: Yu
authors.forename: Frank Fuxiang
authors.initials: FF
authors.lastname: Mao
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Jia-Qing
authors.initials: JQ
authors.lastname: Zhang
authors.forename: Xiu-Ming
authors.initials: XM
authors.lastname: Zhang
authors.forename: Shu-Nong
authors.initials: SN
authors.lastname: Li
authors.forename: Ming-Tao
authors.initials: MT
authors.lastname: Li
authors.forename: Bruce T
authors.initials: BT
authors.lastname: Lahn
authors.forename: Andy Peng
authors.initials: AP
authors.lastname: Xiang
mesh_terms: D002454:Cell Differentiation; D002478:Cells, Cultured; D016000:Cluster Analysis; D015180:Electrophoresis, Gel, Two-Dimensional; D020869:Gene Expression Profiling / Q000379:methods*; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism*; D040901:Proteomics; D020133:Reverse Transcriptase Polymerase Chain Reaction