• Imaging Science in Dentistry
• /
• 제35권3호
• /
• pp.127-131
• /
• 2005

Purpose : We performed the present study to investigate whether osteotropic hormomes play roles on the nitric oxide (NO) production in culture of ROS 17/12.8 osteoblastic cells. Materials and Methods : The osteoblastic cell line ROS17/2.8 cells were cultured In F12 medium supplemented with $5\%$ fetal bovine serum (FBS) at $37^{\circ}C$ in a humidified atmosphere of $5\%\;CO_2$ in air. ROS17/2.8 cells were plated in 96-well plates at a density of $2-3\times10^3cells/well$ and grown to confluence. Then the cells were pretreated with osteotropic hormones (parathyroid hormone (PTH) 20-500 ng/mL, 1, 25-dihydroxycholecalciferol $(1,\;25[OH]_2D_3)$ 1-100 nM; prostaglandin $E_2 (PGE_2)$ 20-500 ng/mL in the medium supplemented with $0.4\%$ FBS for 72 hours and the cells were treated with cytokines $(TNF{\alpha}\;and\;IFN{\gamma})$ in phenol red-free F12 medium for an additional 48 hours. NO synthesis was assessed by measuring the nitrite anion concentration, the reaction product of NO, in the cell culture medium using Griess reagent. Results : PTH and $1,\;25[OH]_2D_3$ pretreatment induced a significant increase in NO production in the presence of $TNF{\alpha}\;and\;IFN{\gamma}.\;PGE_2$ slightly induced NO production compared to the control group. But, $PGE_2$ pretreatment did not affect in NO production in the presence of $TNF{\alpha}\;and\;IFN{\gamma}$. Conclusions : These results suggest that the actions of osteotropic hormones In bone metabolism may be partially mediated by NO in the presence of cytokines.

• Journal of Oral Medicine and Pain
• /
• 제25권1호
• /
• pp.53-62
• /
• 2000

Bone marrow culture systems are widely used to differentiate osteoclast-like cells in vitro using several osteotropic hormones. In this study, we isolated and cultured the mouse bone marrow cells with or without some osteotropic hormones such as parathyroid hormone(PTH), prostaglandin $E_2(PGE_2)$ and $l,25(OH)_2-vitamin$ $D_3$(Vit. $D_3$). We confirmed the formation of osteoclast-like cells morphologically and functionally by the expression of tartrate-resistant acid phosphatase(TRAP) and by their capability to resorb dentin slices. We also studied the effects of transforming growth $factor-{\beta}(TGF-{\beta})$ and epidermal growth factor(EGF) on the Vit. $D_3-induced$ osteoclast-like cell formation. In control, a few multinucleated cells were formed whereas PTH and $PGE_2$ increased the number of multinucleated cells. PTH, $PGE_2$ and Vit. $D_3$ induced the formation of TRAP-positive multinucleated cells. After culture of mouse bone marrow cells on the dentin slices with or without osteotropic hormones, giant cells with diverse morphology were found on the dentin slices under the scanning electronmicroscopy. After removing the attached cells, resorption pits were identified on the dentin slices, and the shape of resorption pits was variable. EGF increased the osteoclast-like cell formation induced by Vit. $D_3$, however, $TGF-{\beta}$ showed biphasic effect, which at low concentration, increased and at high concentration, decreased the osteoclast-like cell formation induced by Vit. $D_3$.

• The Korean Journal of Physiology and Pharmacology
• /
• 제6권5호
• /
• pp.269-274
• /
• 2002

A large number of factors such as osteotropic hormones, cytokines, or growth factors are related to the bone remodeling which is characterized by the coupling of osteoclast-mediated bone resorption and osteoblast-mediated bone formation. Recent investigations have indicated that cytokines such as $interleukin-1{\beta}\;(IL-1{\beta})$ and tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$ play a potential role in the bone resorption associated with a variety of pathological conditions such as inflammatory osteolytic disease. Collagen is the most abundant protein of the extracellular matrix of bone, and the participation of collagenase in bone resorption has been widely investigated. In this study, effects of $IL-1{\beta}$ and $TNF-{\alpha}$ on the release of collagenase from osteoblastic cells were measured. The gelatinase activity was also measured by gel substrate analysis (zymography) after electrophoresis of conditioned media of osteoblastic cell culture. $IL-1{\beta}$ increased the collagenase activity in ROS17/2.8 and HOS cell culture. $TNF-{\alpha}$ also increased the collagenase activity of osteoblastic cells. When two kinds of cytokines were treated simultaneously in the culture of osteoblastic cells, synergistic increase of collagenase activity was seen in ROS17/2.8 cells. $IL-1{\beta}$ and $TNF-{\alpha}$ significantly increased the collagenase activity after 6 hour treatment in the osteoblastic cell culture, and there was no additional increase according to the culture period. Osteoblastic cells released the gelatinase and molecular weight of this enzyme was measured about 70 KDa as assessed by zymogram. $IL-1{\beta}$ and $TNF-{\alpha}$ showed increase of the gelatinase activity produced by ROS17/2.8 and HOS cells. Taken together, this study suggested that $IL-1{\beta}$ and $TNF-{\alpha}$ can modulate bone metabolism, at least in part, by increased release of collagenase and gelatinase from osteoblasts.