Expression of pro- and anti-inflammatory cytokine transcripts in RAW264.7 cells after GPR109A knockdown and LPS stimulation in the presence and absence of niacin. (A) Gene expression analysis of IL-1β, IL-6, TNF-α, and IL-10 transcripts in RAW264.7 cells transfected with scrambled (lanes 1–4) or GPR109A siRNA (lanes 5–8). Treatments groups were untreated controls (lanes 1, 5), niacin only (lanes (2, 6), LPS only (lanes 3, 7) and LPS in the presence of niacin (lanes 4, 8). (B) Densitometric analysis of changes in the expression levels of cytokine genes relative to β-actin. Data presented as Mean ± SD of 3 replicates. * p < 0.05.