Phenotypic analysis of Dlx5 overexpression in post-natal bone.
Dlx5 plays an important role in the embryonic development of mineralized tissues. We hypothesized that Dlx5 also functions in regulating post-natal bone formation in mice. To prove this hypothesis, we infected 5-day-old bone sialoprotein (BSP)/avian retroviral receptor gene (TVA) transgenic mice with replication-competent retroviral vectors expressing wild-type Dlx5 (RCAS-Dlx5WT) and mutated Dlx5 at arginine (R) 31 of its homeodomain (RCAS-Dlx5RH). Immunohistochemistry indicated that RCAS-Dlx5WT increased BSP and osteopontin (OPN) expression, whereas it decreased that of osteocalcin (OC). RCAS-Dlx5RH mediated opposite effects. Semi-quantitative RT-PCR confirmed these results. Ex vivo overexpression of RCAS-Dlx5WT in BSP/TVA calvarial cells promoted, whereas that of RCAS-Dlx5RH inhibited, mineralized nodule formation as compared with that in control cells. Our results suggest that Dlx5 promotes expression of early markers of osteogenic differentiation and increases mineralization post-natally.
Zhang
J
J
Division of Oral Biology, Department of General Dentistry, Tufts University School of Dental Medicine, One Kneeland Street, Boston, MA 02111, USA.
Zhu
J
J
Valverde
P
P
Li
L
L
Pageau
S
S
Tu
Q
Q
Nishimura
R
R
Yoneda
T
T
Yang
P
P
Zheng
W
W
Ma
W
W
Chen
J
J
D000818:Animals; D001120:Arginine / Q000235:genetics; D030161:Avian Proteins / Q000235:genetics; D001842:Bone and Bones / Q000378:metabolism*; D002113:Calcification, Physiologic / Q000235:genetics; D016326:Extracellular Matrix Proteins / Q000235:genetics; D005786:Gene Expression Regulation / Q000235:genetics; D005822:Genetic Vectors / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics*; D058574:Integrin-Binding Sialoprotein; D051379:Mice; D008822:Mice, Transgenic; D009154:Mutation / Q000235:genetics; D015675:Osteocalcin / Q000235:genetics; D010012:Osteogenesis / Q000235:genetics*; D053495:Osteopontin / Q000235:genetics; D010641:Phenotype; D011991:Receptors, Virus / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012795:Sialoglycoproteins / Q000235:genetics
D030161:Avian Proteins; C501120:Dlx5 protein, mouse; D016326:Extracellular Matrix Proteins; D018398:Homeodomain Proteins; C546872:Ibsp protein, mouse; D058574:Integrin-Binding Sialoprotein; D011991:Receptors, Virus; D012795:Sialoglycoproteins; C088745:Tva receptor; D015675:Osteocalcin; D053495:Osteopontin; D001120:Arginine