Table 3.

Osteopontin (keyword: osteopontin and osteoblast, 2006–2011 and published in English)

Author	Type	Cell	Objective	Result
Saito et al. [167]	In vivo	Cells extracted-mouse molar	To clarify the expression of GM-CSF and OPN in the process of reparative dentin formation by allogenic tooth transplantation using in situ hybridization for OPN and immunohistochemistry for GM-CSF and OPN	The secretion of GM-CSF and OPN by immunocompetent cells such as macrophages and dendritic cells plays a role in the maturation of dendritic cells and the differentiation of odontoblasts, respectively, in the regenerated pulp tissue following tooth transplantation
Addison et al. [164]	In vitro	MC3T3-E1 osteoblast	To examine the role of OPN acidic serine- and aspartate-rich motif and its interaction with PHEX enzyme	OPN acidic serine- and aspartate-rich motif inhibits mineralization by binding to hydroxyapatite in a phosphorylation-dependent manner
Grimm et al. [166]	In vivo; healthy men		To investigate the changes in biochemical parameters of bone turnover following human endotoxemia, an experimental model of self-limiting systemic infection and inflammation	The early human response to systemic endotoxemia boosts OPN levels and modifies bone biomarkers, indicating a decrease in the lytic activity of osteoclasts, accompanied by an increase in the activity of immature osteoblasts
Wu et al. [165]	In vitro	Human fetal-osteoblast (hFOB 1.19)	To explore the osteoblastic cellular response to physicochemical characteristics of fluoridated hydroxyapatite	Sintered fluoridated- calcined hydroxyapatite composites could enhance OPN and COL I gene expression after 6-day culture (Pp < 0.05). Otherwise, sintered hydroxy fluorapatites composites inhibited the expression. Sintered fluoridated-calcined hydroxyapatite composites with both OH and OH···F bands were bioactive bone graft materials
Li et al. [159]	In vitro	Osteoblast	To identify whether haploinsufficiency of Nf1 (Nf1±) osteoblasts and their precursors secrete cytokines that have a central role	OPN, a matrix protein found in mineralized tissues and pivotal in modulating osteoclast functions, was present in increased concentrations in Nf1± osteoblasts. Addition of OPN neutralizing antibody to Nf1± osteoblast conditioned media diminished the gain in bioactivity on osteoclast functions, including osteoclast migration and bone resorption
Bernards et al. [170, 171]	In vitro	MC3T3-E1 cell	To compare the cell binding ability of adsorbed BSP and OPN specifically bound to hydroxyapatite	There is a preference for cell binding to HA with adsorbed BSP as compared to OPN, but not to a statistically significant level
Bernards et al. [170, 171]	In vitro	MC3T3-E1 cell	To examine and compare the orientation of BSP under similar circumstances with OPN	OPN is more important than BSP for osteoblast adhesion to the collagen matrix
Ono et al. [160]	In vivo; parathyroid hormone receptor (PPR) transgenic mice		To examine the effects of deficiency of the bone matrix protein osteopontin (OPN) on the systemic effects of PTH specifically within osteoblastic cell lineages	Local feedback regulation by the bone matrix protein OPN also plays a significant role in the regulation of PTH actions
Zirngibl et al. [161]	In vitro	Rat osteosarcoma ROS17/2.8 cells, non-osteoblastic (HeLa) cell lines	To investigate whether the transcriptional regulation by ERRalpha of the gene for OPN	OPN is an ERRalpha target gene whose promoter is regulated by ERRalpha in a cell context-dependent manner and that a predicted silencing mutation in AF2 or a more flexible helix 12 increases ERRalpha transcriptional activity, effects with implications for ERRalpha as a therapeutic target in bone
Addison et al. [173]	In vitro	MC3T3-E1 osteoblast	To investigate the effect of inorganic pyrophosphate on osteoblast function and matrix mineralization	Inorganic pyrophosphate prevents mineralization in MC3T3-E1 osteoblast cultures by at least three different mechanisms that include direct binding to growing crystals, induction of OPN expression, and inhibition of tissue-nonspecific alkaline phosphatase activity
Ishijima et al. [158]	In vitro	Bone marrow cells obtained from hind limb bones of OPN−/− mice	To obtain further insight into the role of OPN in mediating mechanical stress effect on bone	OPN has an important role in the effects of unloading-induced alterations of differentiation of bone marrow into osteoblasts and osteoclasts
Kato et al. [163]	In vivo; wild-type mice		To test whether deficiency of OPN, a secreted phosphorylated protein, could modulate the effects of prostaglandin E receptor agonist	OPN deficiency enhanced the direct anabolic action of prostaglandin E receptor agonist locally injected onto the parietal bone in inducing new bone formation
Liu et al. [92, 162]	In vitro	Osteoblast MC3T3-E1	To attempt to control the orientation/conformation of bone OPN via its specific interactions with type I collagen	The specific binding of OPN to collagen I may naturally orient OPN, thus influencing osteoblast adhesion
Osathanon et al. [80]	In vitro	Human osteoblast-like cells (SaOS-2)	To compare the early response of human osteoblast-like cells (SaOS-2) on commercially pure titanium (cpTi) and titanium-6-aluminium-7-niobium (Ti-6Al-7Nb)	Ti-6Al-7Nb possess a good potential to support SaOS-2 cells on spreading and fibronectin and OPN synthesis, therefore, this material may be one of a candidate material used in implant dentistry