title: Coordinated change between complement C1s production and chondrocyte differentiation in vitro.
abstract: In vitro synthesis of the first component of complement C1s was examined by using hamster epiphyseal chondrocytes (HAC) and human chondrosarcoma cell line HCS-2/8. Hamster and human C1s produced by the cells were quantified by immunoblotting and sandwich enzyme-linked immunosorbent assay (ELISA), respectively. It was possible to measure active and inactive C1s by sandwich ELISA, when we used anti-human C1s monoclonal antibodies, M241 recognizing only active C1s, and M365 and M81 recognizing both active and inactive C1s. Approximately 40% of C1s secreted from HCS-2/8 was found to be activated in the culture medium, whereas C1s from HAC was not. C1s production increased in accordance with chondrocyte differentiation induced by ascorbic acid. In contrast, transforming growth factor-beta1 and basic fibroblast growth factor, which inhibited differentiation, suppressed C1s production. These results confirmed our previous observation showing that C1s synthesis increased with differentiation into hypertrophic chondrocytes in vivo.
authors.affiliation: Division of Biology and Oncology, National Institute of Radiological Sciences, 4-9-1 Anawawa, Inage-ku, Chiba 263, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nakagawa
authors.forename: H
authors.initials: H
authors.lastname: Sakiyama
authors.forename: T
authors.initials: T
authors.lastname: Fukazawa
authors.forename: M
authors.initials: M
authors.lastname: Matsumoto
authors.forename: M
authors.initials: M
authors.lastname: Takigawa
authors.forename: T
authors.initials: T
authors.lastname: Toyoguchi
authors.forename: H
authors.initials: H
authors.lastname: Moriya
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002454:Cell Differentiation; D003173:Complement C1s / Q000096:biosynthesis*; D006224:Cricetinae; D004797:Enzyme-Linked Immunosorbent Assay; D004815:Epidermal Growth Factor / Q000494:pharmacology; D006132:Growth Plate / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D016212:Transforming Growth Factor beta; D004815:Epidermal Growth Factor; D003173:Complement C1s