Effect of lipopolysaccharide on osteoclast and osteoblast differentiation in vitro (CROSBI ID 580987)
Prilog sa skupa u zborniku | sažetak izlaganja sa skupa | domaća recenzija
Podaci o odgovornosti
Šućur, Alan ; Lazić, Elvira ; Cvija, Hrvoje ; Ivčević, Sanja ; Marušić, Ana ; Katavić, vedran ; Kovačić, Nataša ; Grčević, Danka
engleski
Effect of lipopolysaccharide on osteoclast and osteoblast differentiation in vitro
Lipopolysaccharide (LPS), the major component of the outer membrane of gram-negative bacteria, has long been recognized as an important factor in promoting chronic inflammation and is involved in the pathogenesis of inflammation- and infection-induced bone diseases. Although it is known that LPS induces several pro-inflammatory molecules that can enhance bone resorption, and has a direct effect both on osteoclasts and on osteoblasts, the underlying mechanisms of action have not been fully defined. The aim of this study was to clarify the direct effect of LPS on in vitro differentiation of bone cells, osteoclasts and osteoblasts, depending on the dose of LPS and the bone cell differentiation stage at the time of LPS treatment. Osteoclasts were differentiated from bone marrow cells by the addition of RANKL (receptor activator of NF-B ligand) and M-CSF (monocyte/macrophage colony-stimulating factor) ; whereas osteoblasts were differentiated from bone marrow cells by the addition of ascorbic acid, dexamethasone and β-glycerophosphate. Several doses of LPS have been added to osteoblastogenic and osteoclastogenic cultures at various cultivation time-points. Osteoclasts were significantly more sensitive to LPS treatment, showing a detectable response at the very low dose of 0.005 g/mL, whereas osteoblasts showed a detectable response starting with a dose of 2 g/mL. Furthermore, a low dose of 0.025 g/mL LPS completely inhibited osteoclast differentiation, whereas a dose of 10 g/mL only partially suppressed osteoblast differentiation. Results for the time-response experiments, depending on the bone cell differentiation stage at the time of LPS treatment, showed significant inhibition of osteoclastogenesis with LPS added at the culture start-point, but stimulation of osteoclastogenesis when applied on the RANKL-primed commited preosteoclasts. In osteoblastogenis cultures, the direct LPS effect was exclusively inhibitory, but inhibition intensity depended on the time-point and duration of LPS treatment ; the LPS suppressive effect was weaker if applied on the commited preosteoblasts. Activity of the differentiation enzymes, tartarate resistant acid phosphatase (TRAP) for osteoclasts and alkaline phosphatase (AP) for osteoblasts, confirmed the results of the counts of differentiated bone cells. Differentiation gene expression pattern mirrored the dose- and time-response effect of LPS on the number of differentiated bone cells. Expressions of all analyzed osteoclast (RANK, calcitonin receptor, cFms and cFos) and osteoblast (AP, osteocalcin, Runx2, RANKL and osteoprotegerin) differentiation genes were suppressed by LPS during bone cell differentiation. RANKL was the only exception, showing an increase in the expression by LPS. We can conclude that LPS increases bone cell resorption potential by stimulating differentiation and activity of RANKL-primed osteoclasts, and increasing osteoblastic RANKL expression paralleled by suppressed osteoblast differentiation.
LPS; osteoclasts; osteoblasts; differentiation
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nije evidentirano
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Podaci o prilogu
27-27.
2011.
objavljeno
Podaci o matičnoj publikaciji
Godišnji skup Hrvatskog imunološkog društva : knjiga sažetaka = Annula Meeting of the Croatian Immunological Society : Book of Abstract
Rijeka: Hrvatsko imunološko društvo
Podaci o skupu
Godišnji skup Hrvatskog imunološkog društva.
predavanje
07.10.2011-09.10.2011
Rabac, Hrvatska