Non-functional Fas ligand increases the formation of cartilage early in the endochondral bone induction by rhBMP-2.
It has previously been shown that mice with a defect in Fas ligand-mediated apoptosis have an enhancement of ectopic bone formation. We investigated the expression of bone-related markers--alkaline phosphatase, collagen, bone sialoprotein, osteocalcin, osteopontin, and bone morphogenetic proteins (BMP) -2, -4, and -7; and cytokines interleukin-1alpha (IL-1), IL-1beta, and tumor necrosis factor-alpha (TNF-alpha) in ectopic new bone induced by recombinant human (rh) BMP-2 in mice without functional Fas-ligand (gld mice). At day 6 after rhBMP-2 implantation, gld mice formed more cartilage and mesenchyme compared with their wild type littermates. At later stages, gld mice did not differ from the control mice in the volume of newly formed tissue, expressing higher level of BMP genes and lower levels of genes involved in osteoblast maturation--bone sialoprotein and osteopontin. Differences in the levels of expression of IL-1alpha and TNF-alpha were observed only at day 12 after rhBMP-2 implantation. These results suggest that gld mice have an increased recruitment of cells of mesenchymal origin and an abnormal pattern of differentiation and maturation of the newly formed mesenchymal tissues.
Katavić
Vedran
V
Department of Anatomy, Croatian Institute for Brain Research, Zagreb University School of Medicine, Salata 11, HR-10000 Zagreb, Croatia. vkatavic@mef.hr
Grcević
Danka
D
Lukić
Ivan Kresimir
IK
Vucenik
Vladimira
V
Kovacić
Natasa
N
Kalajzić
Ivo
I
Marusić
Ana
A
D000818:Animals; D015152:Blotting, Northern; D001846:Bone Development / Q000235:genetics*; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D002356:Cartilage / Q000187:drug effects / Q000254:growth & development*; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000494:pharmacology; D016212:Transforming Growth Factor beta
C525718:BMP2 protein, human; C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; C505661:FASLG protein, human; D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D008562:Membrane Glycoproteins; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta