Fig. 5.

Amino acid transporter activity after TLR4 silencing. (A) Transfecting trophoblast cells with siRNA targeting TLR4 after 20 h in culture reduced TLR4 mRNA expression to approximately one third of controls at 90 h in culture. Relative TLR4 mRNA expression was measured by quantitative real-time PCR and normalized against the housekeeping genes SDHA and TBP. The mean of the controls was assigned a value of 1.0 AU, n = 3. B, C: Mock transfection with the transfection reagent Dharmafect alone did not alter the response to oleic acid of either system A or system L amino acid transporters. System A activity (B) was increased after a 24 h incubation with oleic acid, while system L activity (C) was unaffected. In trophoblast cells transfected with siRNA targeting TLR4, oleic acid did not increase the system A activity (B), but reduced the system L activity (C). *P < 0.05 compared with all other groups; repeated measures ANOVA followed by Tukey's post hoc test, n = 7.