Sclerostin in mineralized matrices and van Buchem disease.
Sclerostin is an inhibitor of bone formation expressed by osteocytes. We hypothesized that sclerostin is expressed by cells of the same origin and also embedded within mineralized matrices. In this study, we analyzed (a) sclerostin expression using immunohistochemistry, (b) whether the genomic defect in individuals with van Buchem disease (VBD) was associated with the absence of sclerostin expression, and (c) whether this was associated with hypercementosis. Sclerostin was expressed by cementocytes in mouse and human teeth and by mineralized hypertrophic chondrocytes in the human growth plate. In individuals with VBD, sclerostin expression was absent or strongly decreased in osteocytes and cementocytes. This was associated with increased bone formation, but no overt changes in cementum thickness. In conclusion, sclerostin is expressed by all 3 terminally differentiated cell types embedded within mineralized matrices: osteocytes, cementocytes, and hypertrophic chondrocytes.
van Bezooijen
R L
RL
Departments of Endocrinology and Metabolic Diseases, C4R, Leiden University Medical Center, Albinusdreef 2, Leiden 2333 ZA, The Netherlands. R.L.van_Bezooyen@lumc.nl
Bronckers
A L
AL
Gortzak
R A
RA
Hogendoorn
P C W
PC
van der Wee-Pals
L
L
Balemans
W
W
Oostenbroek
H J
HJ
Van Hul
W
W
Hamersma
H
H
Dikkers
F G
FG
Hamdy
N A T
NA
Papapoulos
S E
SE
Löwik
C W G M
CW
D048868:Adaptor Proteins, Signal Transducing; D000293:Adolescent; D000328:Adult; D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000096:biosynthesis* / Q000172:deficiency*; D002648:Child; D019902:Chondrocytes / Q000378:metabolism; D003739:Dental Cementum / Q000378:metabolism; D005260:Female; D005819:Genetic Markers; D006132:Growth Plate / Q000378:metabolism; D006801:Humans; D007569:Jaw Abnormalities / Q000209:etiology; D008297:Male; D008310:Malocclusion / Q000209:etiology; D051379:Mice; D008875:Middle Aged; D010011:Osteocytes / Q000378:metabolism*; D010026:Osteosclerosis / Q000150:complications / Q000000981:diagnostic imaging / Q000378:metabolism*; D011862:Radiography, Panoramic; D014071:Tooth Abnormalities / Q000209:etiology; D055815:Young Adult
D048868:Adaptor Proteins, Signal Transducing; D019485:Bone Morphogenetic Proteins; D005819:Genetic Markers; C422903:SOST protein, human