TY - JOUR
T1 - Identification of novel osteogenic compounds by an ex-vivo sp7
T2 - Luciferase zebrafish scale assay
AU - de Vrieze, Erik
AU - Zethof, Jan
AU - Schulte-Merker, Stefan
AU - Flik, Gert
AU - Metz, Juriaan R.
PY - 2015/5/1
Y1 - 2015/5/1
N2 - Tight interactions among different cell types contributing to bone formation are of key importance in the maintenance of bone homeostasis. Based on the high similarity in responses to (anti)osteogenic signals between zebrafish scales and mammalian bone, we developed and validated a model to screen large numbers of compounds using ex-vivo cultured scales of a sp7:luciferase transgenic zebrafish. This model combines the high predictive value of explant cultures with quick, sensitive, and quantifiable readout converging the effects via various pathways including WNT-signaling, to SP7/osterix promoter activity. Sp7 is pivotal in osteoblast differentiation and activity and its promoter activity provides an excellent surrogate for sp7 expression. Bmp-2a was shown to dose-dependently increase sp7-driven luciferase activity ex vivo. Next, we identified novel effects on bone for 51.7% of the compounds from a small library of WNT-signaling modulators, including a strong osteogenic effect for niclosamide. From all previously characterized compounds, the effect on bone was correctly predicted for 70% of compounds, resulting in a 7% false positive- and 21% false negative rate. The proposed sp7:luciferase zebrafish scale model is unique, powerful and efficient new tool to assess compounds with osteogenic effects, prior to further testing in rodents.
AB - Tight interactions among different cell types contributing to bone formation are of key importance in the maintenance of bone homeostasis. Based on the high similarity in responses to (anti)osteogenic signals between zebrafish scales and mammalian bone, we developed and validated a model to screen large numbers of compounds using ex-vivo cultured scales of a sp7:luciferase transgenic zebrafish. This model combines the high predictive value of explant cultures with quick, sensitive, and quantifiable readout converging the effects via various pathways including WNT-signaling, to SP7/osterix promoter activity. Sp7 is pivotal in osteoblast differentiation and activity and its promoter activity provides an excellent surrogate for sp7 expression. Bmp-2a was shown to dose-dependently increase sp7-driven luciferase activity ex vivo. Next, we identified novel effects on bone for 51.7% of the compounds from a small library of WNT-signaling modulators, including a strong osteogenic effect for niclosamide. From all previously characterized compounds, the effect on bone was correctly predicted for 70% of compounds, resulting in a 7% false positive- and 21% false negative rate. The proposed sp7:luciferase zebrafish scale model is unique, powerful and efficient new tool to assess compounds with osteogenic effects, prior to further testing in rodents.
KW - Bone
KW - Drug design
KW - Elasmoid scales
KW - Osteoblast
KW - Sp7
KW - Zebrafish
UR - http://www.scopus.com/inward/record.url?scp=84921716985&partnerID=8YFLogxK
U2 - 10.1016/j.bone.2015.01.006
DO - 10.1016/j.bone.2015.01.006
M3 - Article
C2 - 25600250
AN - SCOPUS:84921716985
SN - 8756-3282
VL - 74
SP - 106
EP - 113
JO - Bone
JF - Bone
ER -