Gene expressions of trans-regulators of UDP-glucose dehydrogenase ( UGDH ). Specificity protein 1 (Sp1) protein level in was detected in both human and rat cartilage samples (A, B). Relative mRNA levels of Sp1, Sp3 and Krueppel-related zinc finger protein c-Krox (c-Krox) were also detected in human primary chondrocyte treat with IL-1β (C-E). Total and nuclear Sp1 protein level was also detected and quantified (F, G). MNC, microscopically normal cartilage; DC, degenerative cartilage. Scale bars, 100 μm. Values are presented as mean ± standard error of the mean from at least three independent experiments. *P <0.05 and **P <0.01 versus control.