Lysyl oxidase (lox) gene deficiency affects osteoblastic phenotype.
Lysyl oxidase (LOX) catalyzes cross-linking of elastin and collagen, which is essential for the structural integrity and function of bone tissue. The present study examined the role of Lox gene deficiency for the osteoblast phenotype in primary calvarial osteoblasts from E18.5 Lox knockout (Lox ( -/- )) and wild type (wt) (C57BL/6) mice. Next to Lox gene depletion, mRNA expression of Lox isoforms, LOXL1-4, was significantly downregulated in Lox ( -/- ) bone tissue. A significant decrease of DNA synthesis of Lox ( -/- ) osteoblasts compared to wt was found. Early stages of osteoblastic apoptosis studied by annexin-V binding as well as later stages of DNA fragmentation were not affected. However, mineral nodule formation and osteoblastic differentiation were markedly decreased, as revealed by significant downregulation of osteoblastic markers, type I collagen, bone sialoprotein, and Runx2/Cbfa1.
Pischon
N
N
Department of Operative Dentistry and Periodontology, CharitéCentrum 3, University School of Dental Medicine, Charité - Universitätsmedizin Berlin, 14197 Berlin, Germany. nicole.pischon@charite.de
Mäki
J M
JM
Weisshaupt
P
P
Heng
N
N
Palamakumbura
A H
AH
N'Guessan
P
P
Ding
A
A
Radlanski
R
R
Renz
H
H
Bronckers
T A L J J
TA
Myllyharju
J
J
Kielbassa
A M
AM
Kleber
B M
BM
Bernimoulin
J-P
JP
Trackman
P C
PC
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002454:Cell Differentiation / Q000235:genetics; D024042:Collagen Type I / Q000378:metabolism; D050659:Core Binding Factor Alpha 1 Subunit / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis; D015536:Down-Regulation; D018507:Gene Expression Regulation, Developmental; D020868:Gene Silencing; D007527:Isoenzymes / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010006:Osteoblasts / Q000166:cytology / Q000201:enzymology*; D053495:Osteopontin / Q000378:metabolism; D010641:Phenotype; D008249:Protein-Lysine 6-Oxidase / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D012886:Skull / Q000166:cytology / Q000196:embryology
D024042:Collagen Type I; D050659:Core Binding Factor Alpha 1 Subunit; D007527:Isoenzymes; C493716:Runx2 protein, mouse; C506896:Spp1 protein, mouse; D053495:Osteopontin; D004247:DNA; D008249:Protein-Lysine 6-Oxidase