Fig. 3

Possible involvement of OGR1 in CXCL8 production of ASMCs. a ASMCs are transfected with non-targeting RNA (NT-siRNA) or siRNA specific for OGR1 (OGR1-siRNA). The expression of OGR1 mRNA was measured by real-time TaqMan RT-PCR at 48 h after transfection. The expression levels of OGR1 mRNA are standardized to those of GAPDH mRNA expression, and data are expressed as percentages of OGR1 mRNA expression in ASMCs transfected with NT-siRNA (mean ± SEM, n = 5; **, P < 0.01). b At 48 h after ASMCs were transfected with either NT-siRNA or OGR1-siRNA, ASMCs were incubated in pH 6.3 or 7.4 medium for an additional 24 h. Acidic pH-stimulated CXCL8 secretion is suppressed in ASMCs transfected with OGR1-siRNA compared with those transfected with NT-siRNA. Data are expressed as percentages of CXCL8 values in the supernatants of ASMCs transfected with NT-OGR1 after 24-h stimulation by pH 6.3 medium (mean ± SEM, n = 3; **, P < 0.01; NS, not significant). c CXCL8 secretion in TNF-α (10 ng/mL)-stimulated ASMCs is not influenced by extracellular pH (pH 6.3, pH 7.0, and pH 7.4). Data are expressed as percentages of CXCL8 values obtained from the ASMCs stimulated by TNF-α (10 ng/mL) at pH 7.4 for 24 h (mean ± SEM, n = 4; NS, not significant). d TNF-α (10 ng/mL)-stimulated CXCL8 secretion is not inhibited by OGR1 siRNA at pH 7.4, although it is significantly inhibited at pH 6.3. Data are expressed as percentages of CXCL8 values in the supernatants of ASMCs transfected with NT-OGR1 after 24 h-stimulation of TNF-α at pH 7.4 (mean ± SEM, n = 8; **, P < 0.01; NS, not significant)