Insulin-like growth factor binding Protein-3 suppresses osteoblast differentiation via bone morphogenetic protein-2

Journal Article · Sat Dec 15 04:00:00 EST 2018 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2018.11.065· OSTI ID:23100592

Eguchi, Kaori; Akiba, Yosuke; Akiba, Nami; Nagasawa, Masako ^[1]; Uoshima, Katsumi ^[1]

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1. Division of Bio-Prosthodontics, Niigata University Graduate School of Medical and Dental Sciences, Niigata (Japan)

Highlights: • The maintenance of bone mass after induction of bone formation is difficult. • Insulin-like growth factor (IGF)-1 regulates bone mass including osteogenesis. • IGF-binding proteins (IGFBPs) are important for IGF-1 stability. • Bone morphogenetic protein-2 (BMP-2) induces osteoblast differentiation. • IGFBP-3 counteracts the effect of BMP-2 and suppresses bone formation. Bone augmentation therapy is used in dental implantation. While techniques to induce bone formation are generally successful, the maintenance of bone mass is more difficult. Therefore, it is important to understand the mechanisms that regulate this process. Insulin-like growth factor-1 (IGF-1) is one of the most abundant growth factors that regulate bone mass, promote osteoblast differentiation, and accelerate bone formation. The activity of IGF-1 is regulated by IGF-binding proteins (IGFBPs). IGFBP-3 forms a ternary complex with IGF-1, extending its half-life in the circulating system. Therefore, IGFBP-3 acts as a stabilizer and transporter of IGF-1. Recent studies reported new IGF-1-independent functions of IGFBP-3 related with bone metabolism. In this study, we investigated the function of IGFBP-3 in osteoblast differentiation. Our results showed that IGFBP-3 decreases the expression of osteoblast differentiation markers, whose expression is enhanced by bone morphogenetic protein-2 (BMP-2). IGFBP-3 also reduced BMP-2 effect on ALP activity and mineral nodule formation. In addition, IGFBP-3 suppresses the activity of the Smad Binding Element (SBE) reporter, induced by BMP-2 signaling. These results suggest that IGFBP-3 inhibits osteoblast differentiation through the BMP-2 signal pathway, and that IGFBP-3 might play a role in bone mass maintenance in an IGF-1-dependent and -independent manner.

• OSTI ID: 23100592
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 1-4 Vol. 507; ISSN 0006-291X; ISSN BBRCA9
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
BONE MARROW
CONNECTIVE TISSUE CELLS
GROWTH FACTORS
INSULIN
METABOLISM
SKELETON