The role of the Wnt/β-catenin pathway in the effect of implant topography on MG63 differentiation.
Wnt/β-catenin signaling plays a key role in bone formation. To assess the role of this signaling cascade in the response of osteoblasts to the implant topography, human MG63 osteoblasts are cultured on micropitted/nanotubular surface topographies (MNTs) and the transcriptional expressions of Wnt/β-catenin pathway receptors, activators, and inhibitors are measured. β-catenin signaling and cell differentiation are studied in the absence and presence of exogenous Dickkopf 1 (Dkk1) on the MNTs and exogenous Wnt3a on a smooth surface. The expressions of the Wnt/β-catenin pathway receptor low-density lipoprotein receptor-related protein 6 and pathway ligand Wnt3a are up-regulated by the MNTs whereas those of the pathway inhibitors including Dkk1/2 and secreted frizzled-related protein 1/2 are down-regulated by the MNTs, indicating regulation of the Wnt/β-catenin pathway modulators to activate the pathway. Consequently, the β-catenin signaling activity is enhanced by the MNTs as well as cell differentiation in terms of osteogenesis-related gene expressions and alkaline phosphatase and collagen products. On the smooth surface, exogenous Wnt3a stimulates β-catenin signaling and cell differentiation while exogenous Dkk1 attenuates the enhancement by the MNTs. The results explicitly demonstrate that the implant topography regulates the product of the Wnt/β-catenin pathway modulators from the cells and in turn activates the cell Wnt/β-catenin pathway promoting osteoblast differentiation.
Department of Prosthetic Dentistry, School of Stomatology, The Fourth Military Medical University, No. 145 West Changle Road, Xi'an 710032, China.
Wei
W
Wang
Lingzhou
L
Zhao
Qianli
Q
Ma
Qintao
Q
Wang
Paul K
PK
Chu
Yumei
Y
Zhang
D000469:Alkaline Phosphatase / Q000378:metabolism; D017209:Apoptosis; D002454:Cell Differentiation; D002460:Cell Line; D002470:Cell Survival; D003094:Collagen / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D013499:Surface Properties; D054457:Tissue Scaffolds / Q000737:chemistry*; D051153:Wnt Proteins / Q000378:metabolism*; D060449:Wnt Signaling Pathway; D060509:Wnt3A Protein / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism*
C501126:DKK1 protein, human; D036341:Intercellular Signaling Peptides and Proteins; D051153:Wnt Proteins; D060509:Wnt3A Protein; D051176:beta Catenin; D003094:Collagen; D000469:Alkaline Phosphatase