Upregulation of GPR40 and CD36 mRNA expression by LPS and palmitate, and the involvement of GPR40 and CD36 in the stimulation of IL-6 expression by LPS and palmitate. A. Human gingival fibroblasts were treated with 1 μg/ml of Pg LPS, 100 μM of palmitate or both 1 μg/ml of Pg LPS and 100 μM of palmitate for 24 h. After the treatment, GPR40 mRNA was quantified using real-time PCR. B. RAW264.7 macrophages were treated with 1 μg/ml of Pg LPS, 100 μM of palmitate or both 1 μg/ml of Pg LPS and 100 μM of palmitate for 24 h. After the treatment, CD36 mRNA was quantified using real-time PCR. C and D. Human gingival fibroblasts were treated with 1 μg/ml of Pg LPS, 100 μM of palmitate or both 1 μg/ml of Pg LPS and 100 μM of palmitate in the absence or presence of 5 μM of GW1100 (C) or 100 μM of SSO (D) for 24 h. After the treatment, IL-6 mRNA was quantified using real-time PCR. The data (mean ± SD) presented is from representative of three experiments with similar results.