Figure 6

Knockdown of GPR120 expression reduces the anti-inflammatory effect of docosahexaenoic acid (DHA). A (i). Western blot of rHypoE-7 cells treated with GPR120-specific or scrambled (Scr) siRNA for 24 hr showing that exposure to GPR120-specific siRNA reduced endogenous GPR120 protein levels by approximately 75% (ii). Scr; light gray bar: 1.18 ± 0.08 and GPR120; dark gray bar: 0.26 ± 0.05 GPR120/β-actin, n = 4). B. GPR120 reduction significantly impaired the ability of DHA (100 μM, 1 hr pretreatment) to reduce IκBα (i) (Scr: 0.63 ± 0.09 and GPR120: 1.11 ± 0.07 IκBα/histone) and TNFα (ii) (Scr: 0.82 ± 0.06 and GPR120: 1.35 ± 0.10 TNFα/histone) mRNA levels upon TNFα treatment (10 ng/mL, 2 hr). C. Reduction of GPR120 levels by siRNA significantly impaired the ability of DHA to reduce TNFα protein production relative to Scr controls (Scr + DHA = 0.20 ± 0.03 and GPR120 + DHA = 0.44 ± 0.03 TNFα/β-actin, n = 3). Data are shown as mean ± SEM; *P <0.05; ***P <0.01; not significant (NS).