Yoshikazu Mikami: Department of Pathology, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan.
Hiromasa Tsuda: Department of Biochemistry, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan. tsuda.hiromasa@nihon-u.ac.jp.
Yuko Akiyama: Department of Orthodontics, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan.
Masaki Honda: Department of Oral Anatomy, Aichi-Gakuin University School of Dentistry, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi, 464-8650, Japan.
Noriyoshi Shimizu: Department of Orthodontics, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan.
Naoto Suzuki: Department of Biochemistry, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan.
Kazuo Komiyama: Department of Pathology, Nihon University School of Dentistry, 1-8-13 Kanda Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan.
Polyphosphate [Poly(P)] has positive effects on osteoblast mineralization; however, the underlying mechanism remains unclear. In addition, it is unknown whether Poly(P) promotes mineralization in soft tissues. We investigated this by using various cells. Poly(P) concentrations of 1 and 0.5 mg/mL yielded high levels of mineralization in ROS17/2.8 osteoblast cells. Similarly, Poly(P) induced mineralization in cell types expressing alkaline phosphatase (ALP), namely, ATDC5 and MC3T3-E1, but not in CHO, C3H10T1/2, C2C12, and 3T3-L1 cells. Furthermore, forced expression of ALP caused Poly(P)-induced mineralization in CHO cells. These results suggest that ALP determines Poly(P)-induced mineralization in a cell-type independent manner.