title: Proteomics based detection of differentially expressed proteins in human osteoblasts subjected to mechanical stress.
abstract: Mechanical stress is essential for bone development. Mechanical stimuli are transduced to biochemical signals that regulate proliferation, differentiation, and cytoskeletal reorganization in osteoblasts. In this study, we used proteomics to evaluate differences in the protein expression profiles of untreated Saos-2 osteoblast cells and Saos-2 cells subjected to mechanical stress loading. Using 2-D electrophoresis, MALDI-TOF mass spectroscopy, and bioinformatics, we identified a total of 26 proteins differentially expressed in stress loaded cells compared with control cells. Stress loaded Saos-2 cells exhibited significant upregulation of 17 proteins and significant downregulation of 9 proteins compared with control cells. Proteins that were most significantly upregulated in mechanically loaded cells included those regulating osteogenesis, energy metabolism, and the stress response, such as eukaryotic initiation factor 2 (12-fold), mitochondrial ATP synthase (8-fold), and peptidylprolyl isomerase A (cyclophilin A)-like 3 (6.5-fold). Among the proteins that were significantly downregulated were those involved in specific signaling pathways and cell proliferation, such as protein phosphatase regulatory (inhibitor) subunit 12B (13.8-fold), l-lactate dehydrogenase B (9.4-fold), Chain B proteasome activator Reg (Alpha) PA28 (7.7-fold), and ubiquitin carboxyl-terminal esterase L1 (6.9-fold). Our results provide a platform to understand the molecular mechanisms underlying mechanotransduction.
authors.affiliation: Department of Orthodontics, School of Stomatology, Fourth Military Medical University, Xi'an, 710032 Shannxi Province, China.
authors.forename: Fei-Fei
authors.initials: FF
authors.lastname: Li
authors.forename: Fu-Lin
authors.initials: FL
authors.lastname: Chen
authors.forename: Huan
authors.initials: H
authors.lastname: Wang
authors.forename: Shi-Bin
authors.initials: SB
authors.lastname: Yu
authors.forename: Ji-Hong
authors.initials: JH
authors.lastname: Cui
authors.forename: Yin
authors.initials: Y
authors.lastname: Ding
authors.forename: Xue
authors.initials: X
authors.lastname: Feng
mesh_terms: D002460:Cell Line; D004734:Energy Metabolism / Q000235:genetics; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006801:Humans; D040542:Mechanotransduction, Cellular / Q000235:genetics*; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D010012:Osteogenesis / Q000235:genetics; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D040901:Proteomics; D013314:Stress, Mechanical; D013312:Stress, Physiological / Q000235:genetics
chemical_list: D011506:Proteins