Figure 3.

Down-regulation of nAChR subunits α7, α9 or α10 by siRNA abolished the inhibitory potential of ACh or PC. U937 cells were transfected with siRNA targeting CHRNA7 (α7), CHRNA9 (α9), CHRNA10 (α10) or with scrambled siRNA. Forty-eight hours after transfection, cells were primed with lipopolysaccharide (LPS; 1 μg/ml) for 5 h and BzATP (100 μM) was given for additional 30 min in the presence or absence of ACh (10 μM) (A) or PC (100 μM) (B). BzATP induced the release of IL-1β, which was inhibited in the presence of ACh or PC in cells transfected with scrambled siRNA. Down-regulation of the nAChR subunit α7 blunted the effect of ACh (A) or PC (B). Similarly, reduced expression of the α9 and α10 nAChR subunits diminished the inhibitory potential of ACh (A). The IL-1β concentration was measured by ELISA. Data were analyzed by Kruskal-Wallis test followed by Mann-Whitney rank sum test and presented as individual data points, bars represent median, whiskers percentiles 25 and 75. *p ≤ 0.05 significantly different from samples where BzATP was given alone.