373회 Application of Proteomics Strategies to Osteoclast Biology Resear…

373회

연사 :  김 홍 희, 서울대학교 치의학과 세포발생학

제목:  Application of Proteomics Strategies to Osteoclast Biology Research

Abstract

  Recently there has been a great development in proteomics technology. Proteomics approach is an efficient way for the identification of proteins showing differential expression levels between targeted cells and tissues and their reference counterparts. Proteomics approaches also have revealed new links ofmany proteins to previously unexpected biological responses. We have employed the two-dimensional electrophoresis-based proteomics approach to find proteins of which expression is regulated during osteoclast differentiation and found that the expression of brain isoform of ceatine kinase is highly up-regulated during osteoclastogenesis. To investigate the functional significance of ceatine kinase brain isoform expression in osteoclasts, we examined the effects of blocking the activity of this enzyme or reducing the expression level on osteoclast differentiation and resorption activity. Ectopic expression of two different kinds of dominant-negative forms of this enzyme resulted in a decrease in multinucleated TRAP-positive osteoclasts. A pharmacological inhibitor of creatine kinase also suppressed multinucleated osteoclast formation. Duringgeneration ofactin ring structure, creatine kinase brain isoform became colocalized with actin ring. The creatine kinase inhibitor disrupted this colocalizationthe resorption function of osteoclasts. Inhibition of the expression of creatine kinase brain isoform by antisense oligonucleotide or RNAi also showed reduced osteoclast multinucleation and activity. Finally, in several animal models, the creatine kinase inhibitor reduced osteoclast activity under conditions where remodeling was stimulated by IL-1, RANKL, or LPS. Taken together, these data demonstrate that the brain isoform of ceatine kinase has important roles in osteoclast function.