title: MC3T3-E1-conditioned medium-induced mineralization by clonal rat dental pulp cells.
abstract: Dental pulp is thought to participate in supplementary mineralization, such as reparative dentin and pulp stones, but no direct proof of this has been reported. To study this process at a molecular level, we investigated the matrix mineralization of dental pulp using a clonal cell line (RPC-C2A) derived from rat incisor dental pulp. Mineralized nodules in extracellular matrix were formed by RPC-C2A cells cultured in the presence of conditioned medium (CM) from confluent osteoblastic MC3T3-E1 cells. These nodules were stained by the von Kossa method and with alizarin red S and quantified by the measurement of acid-soluble calcium deposition. This CM was most effective when collected 3-6 days after confluency and added at 50% to the culture medium. The CM-treated RPC-C2A cells showed high alkaline phosphatase activity, a high mRNA level of osteocalcin and decreases in the mRNA levels of osteopontin and osteonectin, but undetectable levels of mRNA of dentin sialophosphoprotein by Northern blot analyses. A pan-specific anti-transforming growth factor (TGF)-beta antibody and a soluble form of receptor for bone morphogenetic protein (BMP)-2/-4 did not neutralize the CM-induced mineralization. These results suggest that some soluble factor(s) other than TGF-beta or BMP-2/-4 in the CM from MC3T3-E1 cells cause differentiation of RPC-C2A cells to osteoblast-like cells.
authors.affiliation: Department of Biochemistry, School of Dentistry, The University of Tokushima, 3-18-15 Kuramoto-cho, Tokushima 770-8504, Japan. akemichi@dent.tokushima-u.ac.jp
authors.forename: A
authors.initials: A
authors.lastname: Ueno
authors.forename: Y
authors.initials: Y
authors.lastname: Kitase
authors.forename: K
authors.initials: K
authors.lastname: Moriyama
authors.forename: H
authors.initials: H
authors.lastname: Inoue
mesh_terms: D000469:Alkaline Phosphatase / Q000187:drug effects*; D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000378:metabolism; D002460:Cell Line / Q000166:cytology; D002999:Clone Cells; D018920:Coculture Techniques; D017077:Culture Media, Conditioned / Q000378:metabolism / Q000494:pharmacology*; D003782:Dental Pulp / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D003784:Dental Pulp Calcification / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: D019485:Bone Morphogenetic Proteins; D017077:Culture Media, Conditioned; D016326:Extracellular Matrix Proteins; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D000469:Alkaline Phosphatase