title: Induction of endosomal/lysosomal pathways in differentiating osteoblasts as revealed by combined proteomic and transcriptomic analyses.
abstract: We have analyzed proteome changes associated with bone-forming osteoblast differentiation by quantitative differential proteomic and transcriptomic analyses using in vitro differentiation model. Sixty nine proteins were found up-regulated (>2-fold) and 18 were down-regulated (<0.5-fold) at protein level. The mRNA levels of these proteins were then analyzed by quantitative real-time PCR combined with clustering analysis. The most prominent cluster with increased protein and mRNA levels contains endosomal and lysosomal proteins, demonstrating the drastic induction of degradative endosomal/lysosomal pathways in osteoblasts. Osteoblasts, therefore, are involved not only in the synthesis but also in the turnover of the extracellular matrix proteins such as collagens.
authors.affiliation: Institute for Enzyme Research, University of Tokushima, Tokushima, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Taniguchi
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Kido
authors.forename: Emiko
authors.initials: E
authors.lastname: Yamauchi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Abe
authors.forename: Toshio
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Hisaaki
authors.initials: H
authors.lastname: Taniguchi
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D020869:Gene Expression Profiling / Q000379:methods; D008247:Lysosomes / Q000378:metabolism*; D051379:Mice; D008813:Mice, Inbred ICR; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism*; D020543:Proteome; D040901:Proteomics / Q000379:methods
chemical_list: D020543:Proteome