Figure 2

Effects of CoPP on HO-1 expression and sGAG synthesis in human NP cells (a) Western blot analysis revealed that HO-1 protein levels were remarkably increased by CoPP in the presence or absence of IL-1β. (b,c) Immunofluorescence microscopy showed that the immunostaining and relative immunofluorescence intensity of CS, the major component of sGAG, were lower after IL-1β stimulation and this effect was ameliorated by HO-1 induction (bars = 100 μm). (d) DMMB assay showed that the HO-1 inducer CoPP considerably rescued the loss of sGAG content caused by IL-1β without influencing basal sGAG synthesis. Values represent the mean and SD. *P < 0.05 with respect to IL-1β.