TCM regulated IL-6–mediated glutamine synthesis via TLR4/Syk/NF-κB pathway. (A) FACS analysis of TLR4 expression in NFs upon TCM treatment. (B) WT NFs or TLR4^KO NFs were treated with TCM for 24 h. ELISA of IL-6 protein level was checked. (C) Western blots of NF-κB signal pathway activation in WT NFs or TLR4^KO NFs upon TCM treatment at indicated different time points. (D) WT NFs or TLR4^KO NFs were treated with palmitate conjugated with BSA (200 μM) for 24 h. BSA alone was used as a control. ELISA of IL-6 protein level was checked. (E) Western blots of NF-κB signal pathway activation in WT NFs or TLR4^KO NFs upon palmitate treatment for 24 h (n = 3). Data are representative of at least two independent experiments with similar results (A–E). All data are shown as mean ± SEM and were analyzed by two-tailed, unpaired Student’s t test (A) or one-way ANOVA with Tukey’s multiple comparison test (B and D). ****P < 0.0001; ***P < 0.001, **P < 0.01; *P < 0.05; P > 0.05 not significant (ns). Source data are available for this figure: SourceData F5.