title: Cytokine-induced apoptosis inhibitor-1 causes dedifferentiation of rabbit articular chondrocytes via the ERK-1/2 and p38 kinase pathways.
abstract: Cytokine-induced apoptosis inhibitor-1 (CIAPIN-1, formally named anamorsin) is a well-known regulator of apoptosis in many different cell types. Recently, it has been reported that some anti-apoptotic proteins are involved with the regulation of cell differentiation. However, relatively little is known about the role of CIAPIN-1 on rabbit articular chondrocytes differentiation. In this study, we investigated the effects of CIAPIN-1 in chondrocytes, focusing on extracellular signal-regulated kinase (ERK)-1/2 and p38 kinase signaling. CIAPIN-1 caused dedifferentiation, as determined by the inhibition of type II collagen expression and sulfated-proteoglycan synthesis. CIAPIN-1 activated ERK-1/2 and inactivated p38 kinase, as determined by the phosphorylation level of each protein. CIAPIN-1-induced ERK phosphorylation was abolished by the MEK inhibitor, PD98059, which also prevented the CIAPIN-1-induced loss of type II collagen expression. Inhibition of p38 kinase with SB203580 enhanced the decrease in type II collagen expression. Our findings collectively suggest that ERK-1/2 and p38 kinase regulate CIAPIN-1-induced dedifferentiation in rabbit articular chondrocytes.
authors.affiliation: Department of Biological Sciences, College of Natural Sciences, Kongju National University, Gongju, Republic of Korea.
authors.forename: Seon-Mi
authors.initials: SM
authors.lastname: Yu
authors.affiliation: Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon, Republic of Korea.
authors.forename: Hyeon Ji
authors.initials: HJ
authors.lastname: Yeo
authors.affiliation: Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon, Republic of Korea.
authors.forename: Soo Young
authors.initials: SY
authors.lastname: Choi
authors.affiliation: Department of Biological Sciences, College of Natural Sciences, Kongju National University, Gongju, Republic of Korea. Electronic address: ksj85@kongju.ac.kr.
authors.forename: Song Ja
authors.initials: SJ
authors.lastname: Kim
mesh_terms: D000818:Animals; D017209:Apoptosis; D002454:Cell Differentiation; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D004789:Enzyme Activation; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D011817:Rabbits; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: C489114:CIAPIN1 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases
keywords: CIAPIN-1; Chondrocytes; Dedifferentiation; ERK-1/-2; p38 kinase