fig5

Figure 5. Caco-2 polarized monolayers released pro-inflammatory cytokines in response to LPS and more so in the co-presence of FFAs. Secretion of TNF-α (A), IL6 (B), and IL1β (C) was measured in concentrated culture media from the basolateral compartment and normalized for the total protein content. pTLR4 and total TLR4 protein levels were evaluated in lysates from HepG2 cells co-cultured with Caco-2 stimulated with LPS and/or PAOA using Western blot. The expressions were normalized for the housekeeping gene β-actin. For each condition, fresh protein lysates of at least three independent experiments were pooled (D). TNF-α mRNA levels were evaluated by qRT-PCR in HepG2 cell lysates and normalized to β-actin (E). For violin plots, data are expressed as median concentration (thick dashed lines) and interquartile range (dotted lines). At least three independent experiments were conducted and pooled together. ***P < 0.0001, **P < 0.001 according to one-way ANOVA. LPS: Lipopolysaccharides; FFAs: free fatty acids; TNF-α: tumor necrosis factor alpha; IL6: interleukin 6; TLR4: toll-like receptor 4; PAOA: palmitic and oleic acid; ANOVA: one-way analysis of variance.