Laminin-5 suppresses chondrogenic differentiation of murine teratocarcinoma cell line ATDC5.
Laminin-5 is an important basement membrane protein that regulates cell adhesion and motility. It was previously found that the gamma2 chain of laminin-5 is transiently expressed in embryonic cartilage. This suggests a possible role of laminin-5 in chondrogenesis. Here, we examined this possibility using the murine teratocarcinoma cell line ATDC5. ATDC5 cells transiently and weakly expressed laminin-5 when they were stimulated for differentiation. Exogenous laminin-5 in either insoluble or soluble form strongly inhibited the differentiation phenotypes, i.e. formation of cartilaginous cell aggregates and production of chondrogenic marker proteins through its integrin-binding domain LG3 in the alpha3 chain. Laminin-5 had no effect on cell growth. In addition, we found that the laminin-5 with the 105-kDa, processed gamma2 chain suppressed differentiation more strongly than one with the 150-kDa gamma2 chain. This indicated that the proteolytic processing of gamma2 chain regulated the activity of laminin-5. However, a gamma2 chain short arm fragment had no effect on the chondrogenesis, and it rather suppressed the differentiation at excessive concentrations. These results suggest that laminin-5 and its processing modulate chondrogenic differentiation during development.
Hashimoto
Junko
J
Division of Cell Biology, Kihara Institute for Biological Research, Yokohama City University, 641-12 Maioka-cho, Totsuka-ku, Yokohama 244-0813, Japan.
Ogawa
Takashi
T
Tsubota
Yoshiaki
Y
Miyazaki
Kaoru
K
D000818:Animals; D002356:Cartilage / Q000166:cytology / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D019902:Chondrocytes / Q000166:cytology*; D051379:Mice; D017434:Protein Structure, Tertiary; D018243:Teratocarcinoma; D000097794:Kalinin
D015815:Cell Adhesion Molecules; D000097794:Kalinin