Figure 2.

Enhancement of cytokine-induced NOS II mRNA expression by atorvastatin and lovastatin in human DLD-1- and A549/8 cells. (A) Representative RNase protection assay performed with total RNA from human DLD-1 cells incubated for 8 h with serum-free medium alone (Co) or with serum-free medium containing a mixture of cytokines (CM; 100 u ml⁻¹ IFN-γ and 10 ng ml⁻¹ TNF-α and 50 u ml⁻¹ IL-1β) in the presence or absence of atorvastatin (atorva; 3–100 μM) and lovastatin (lova; 3–100 μM), respectively. Cells were preincubated for 18 h with serum-free medium with or without statins. Experiments were performed using antisense RNA probes for human NOS II and β-actin (for normalization). The positions of the protected NOS II- and β-actin fragments are indicated. (T: tRNA lane, negative control; A: β-actin antisense probe; N: NOS II antisense probe; M: molecular weight standard, φX174 restricted with HinfI). (B) Densitometric analyses of ten different gels similar to the one shown in (A). Columns (means±s.e.mean) represent relative NOS II mRNA levels at the different concentrations of the respective statin (^*=P<0.05; ^**=P<0.01; ^***=P<0.001; ns=not significant vs CM). (C) Data similar to (B) generated with A549/8 cells. Columns (means±s.e.mean) represent the relative NOS II mRNA levels at the different concentration of the respective statin (^**=P<0.01; ^***=P<0.001; ns=not significant vs CM).