title: Proteomic analysis of chondrocytes exposed to pressure.
abstract: Chondrocytes are the only cell type present in mature articular cartilage (2-5% of total tissue). The biological activities of the chondrocyte population are regulated by genetic, biologic and biochemical factors, as well as environmental factors (stress, flow and electric field). Although compressive forces within joint articular cartilage are required for maintenance of the normal composition of articular cartilage, there is a lack of knowledge about the number of pressure-related proteins expressed in articular cartilage. Two-dimensional gel electrophoresis (2-DE) and high-performance liquid chromatography-electrospray/tandem mass spectrometry (HPLC/ESI-MS/MS) were used to identify the levels of pressure-related proteins expressed by chondrocytes grown in the presence or absence of hydrostatic pressure. A total of 266 spots were excised from the gels and analyzed by HPLC/ESI-MS/MS. Functional classification of up-regulated proteins indicated that energy and protein fate were the main biological processes occurring in pressurized chondrocytes. Furthermore, membrane-bound transferrin-like protein p97, a marker of chondrocyte differentiation, was only expressed in chondrocytes under hydrostatic pressure. These data suggest that hydrostatic pressure can induce cell differentiation by increasing the expression level of energy metabolism- and protein fate-related proteins, indicating that hydrostatic pressure may be needed for normal biosynthesis and differentiation of articular chondrocytes.
authors.affiliation: Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Yu-Min
authors.initials: YM
authors.lastname: Juang
authors.forename: Chun-Yi
authors.initials: CY
authors.lastname: Lee
authors.forename: Wei-Yi
authors.initials: WY
authors.lastname: Hsu
authors.forename: Chiung-Tsung
authors.initials: CT
authors.lastname: Lin
authors.forename: Chien-Chen
authors.initials: CC
authors.lastname: Lai
authors.forename: Fuu-Jen
authors.initials: FJ
authors.lastname: Tsai
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D019902:Chondrocytes / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D015180:Electrophoresis, Gel, Two-Dimensional; D005786:Gene Expression Regulation; D006874:Hydrostatic Pressure; D008969:Molecular Sequence Data; D011506:Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D040901:Proteomics / Q000295:instrumentation; D011817:Rabbits; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D011506:Proteins