Effect of extracellular calcium on the gene expression of bone morphogenetic protein-2 and -4 of normal human bone cells

Abstract

A high extracellular calcium level inhibits the formation of osteoclast-like cells and stimulates osteoblastic proliferation, indicating that extracellular calcium plays an important role in the process of bone remodeling. The present study examined the effects of a high extracellular calcium level on mRNA levels of bone morphogenetic protein (BMP)-2 and -4, which are well-documented osteoinductive proteins, and the differentiation of normal human mandible-derived bone cells in vitro. High extracellular calcium significantly increased cell proliferation at an optimal dose of 0.4mM CaCl2 added to control medium containing 1.8 mM CaCl2. The addition of 0.1-0.4mM CaCl2 markedly increased the mRNA levels of BMP-2 and -4 following incubation for 0.5 and 24 h as evaluated by reverse transcription-polymerase chain reaction. While an increased extracellular calcium level (addition of 0.1-1.2mM CaCl2) failed to increase alkaline phosphatase activity and osteocalcin secretion, it did significantly increase type I collagen synthesis, monitored by the production of procollagen type I carboxy-terminal peptide. These results indicate that the extracellular calcium level regulates BMPs and type I collagen synthesis in osteoblastic cells.

Calcium phosphate-bearing matrices induce osteogenic differentiation of stem cells through adenosine signaling

“…In addition to BMPs, other osteoinductive molecules (e.g., NEL-like molecule-1) have been shown to promote preosteoblast mineralization through SLC20a1 (55). Conversely, supplementation of PO 3 4− in growth medium has been shown to up-regulate BMP-2 expression of various cells similar to other metal ions, such as Ca 2+ and strontium (18,24,25,56). Together, the results propose a molecular mechanism, depicted in Fig.…”

Effect of Bioaggregate on Mineral-associated Gene Expression in Osteoblast Cells

“…Calcium ions are released from hydrated MTA when MTA powder is mixed with water (13). The amount of calcium released has been shown to be adequate to support the proliferation and survival of osteoblast cells (17,18). The chemical component of BA, consisting of calcium silicate, calcium hydroxide, and hydroxyapatite, is similar to that of MTA.…”

Bone formation in CaP‐coated and noncoated titanium fiber mesh

“…39 It is also known that Ca 2+ ions can stimulate cells within the osteogenic lineage to express BMP-2 and BMP-4 mRNA, to produce collagen type I, and to proliferate. 40, 41 An additional effect of a CaP coating can be achieved due to the high affinity of CaP ceramics to bone growth stimulating proteins, such as BMPs. 42,43 This last suggestion has recently been confirmed for thin CaP coatings.…”