Identification of important interactions between subchondral bone ...

use a range of assays ranging from isolated chondrocytes through
ex vivo explants to mesenchymal stem cell differentiation and alginate
beads. In the present study, we used a murine ex vivo femoral
head model [29], and found that PRED decreased bone turnover
S.H. Madsen et al. / Steroids 76 (2011) 1474–1482 1479
Fig. 3. The effects of prednisolone and dexamethasone in resting and activated cartilage. Bovine articular cartilage explants were cultured in the presence of 100 nM
prednisolone (PRED), 100 nM dexamethasone (DEX), and/or cytokines (O + T) [10 ng/ml] + [20 ng/ml] (gray bars) and/or IGF-I [100 ng/ml] (light gray bars) for 3 weeks. Cell
viability was measured with alamar blue after 3 weeks (A and E) and biomarkers were measured at day 19 (B–D and F–H). Explants cultured for 3 weeks were stained with
toluidine blue to evaluate proteoglycan content (I–N and O–T). MMP-mediated aggrecan degradation was measured with 342-G2 (B and F). Collagen type II degradation and
formation were measured by the markers, CIIM (E) and PIINP (F), respectively. PRED/DEX [100 nM] treatment did not affect the cartilage. However, cytokine-induced
degradation were attenuated by 100 nM PRED/DEX. PRED [100 nM] was less potent than DEX [100 nM]. Each treatment n P 5.
Fig. 4. The effect of dexamethasone in non-stimulated and anabolic activated osteoblasts. Osteoblasts were cultured in the presence or absence of 100 nM dexamethasone
(DEX), in non-stimulated (black bars) or 30 ng/ml BMP-2 stimulated (gray bars) cells for 10 days. Cell viability was measured with alamar blue after 10 days (A) and bone
formation was measured by extraction of Alizarin Red-S from stained mineralized bone nodules at day 10 (B). Osteoblastogenesis was measured by alkaline phosphatase
activity in the supernatants accumulated over 10 days (C). DEX [100 nM] treatment decreased viability, bone formation and osteoblastogenesis. However, DEX [100 nM]
increased bone formation in BMP-2 [30 ng/ml] stimulated osteoblasts (B). Each treatment n P 4.
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while mediating anti-catabolic effects on cartilage. Whether osteoclasts,
osteoblasts and chondrocytes were affected directly or indirectly
by PRED, were investigated by separate cell or explants
cultures. To evaluate the effect of GCs directly on chondrocytes,