Figure 2.

Heparan sulphate (HS) or lipopolysaccharide (LPS) -induced activation of caspase-1 in RAW264.7 cells was suppressed by paxilline. RAW264.7 cells were maintained in Dulbecco's modified Eagle's medium containing 10% fetal bovine serum at 37° with 5% CO₂. (a) Cells were incubated for 4 hr with HS (1 μg/ml) alone or in the presence of paxilline (2 μg/ml) or tetraethylammonium (TEA; 1 mg/ml), or anti-Toll-like receptor 4 (TLR4) monoclonal antibody (20 μg/ml), respectively. (b) Cells were also incubated for 4 hr with LPS (10 ng/ml) alone or in the presence of paxilline (2 μg/ml) or TEA (1 mg/ml), or anti-TLR4 monoclonal antibody (20 μg/ml), respectively. Cells treated with only PBS served as control. After cells (5 × 10⁶ in 500 μl) were lysed and centrifuged at 10 000 g for 4 min, the supernatants were collected and incubated with 40 μm YVAD-pNA, followed by incubation at 37° for 2 hr. The caspase-1 activity was measured at 405 nm using a microplate reader. *P < 0·05, compared with HS or LPS; ^#P < 0·05, compared with control. The data (mean ± SE) of one out three experiments run in triplicates with similar results are shown.