Figure 5

IGF-1 mRNA levels in cultured human chondrocytes and the effects of IL-1β and progrado. Primary cultures of human chondrocytes taken from surgical explants were examined for IGF-1 gene expression using real time RT-PCR. Basal expression was normalized to the house keeping gene β-actin. Given that lower doses of progrado were more effective in raising IGF-1 production and cultured chondrocytes do not have cartilage matrux as a barrier to agent penetration only the low dose of progrado (2 μg/ml) was evaluated. Treatment with IL-1β resulted in a significant suppression of IGF-1 mRNA levels (* P < 0.001). However, co-treatment with progrado (2 μg/ml) and IL-1β resulted in a significant increase in IGF-1 gene expression above untreated controls and IL-1β treatment (** P < 0.001). Treatment with progrado alone (2 μg/ml) was able to stimulate IGF-1 mRNA levels above all other groups (** P < 0.001). Results expressed as the mean ± SEM.