Figure 6
Palmitic acid required TLR4 to partially impair insulin signaling and induced inflammation. (Panel A) Human SH-SY5Y cells were transiently transfected with siTLR4 or scramble (control siRNA) and then TLR4 expression was measured by RT-qPCR. Data were presented as means ± SEM (n = 3). *** denoted p < 0.001 when comparing control siRNA to TLR4siRNA, statistical analysis was performed using Student t-test. (Panel B) Human SH-SY5Y cells were transiently transfected with siTLR4 or scramble (control siRNA), cells were cultured in the presence or absence of palmitic acid and then TNFα expression measured by RT-qPCR. Data were presented as means ± SEM (n = 3). * and ** denoted p < 0.05 and p < 0.01, respectively, when comparing control vs palmitate for both cells exposed to control or palmitate condition, statistical analysis was performed using Student t-test. (Panel C) Human SH-SY5Y cells transfected with control siRNA (scramble) or siTLR4 were preatreated with or without palmitic acid during 4 h then acutely stimulated by insulin. The upper part of panel C shows representative Western blots using anti-pAkt, anti-p-ERK1/2 or anti-αTubilin antibodies and each antibody was used in different membranes. The lower part of panel C shows band density quantification. Phosphorylated Akt and Erk1/2 were normalized to αTubilin. Data were presented as means ± SEM (n = 3). # and ## denoted significant differences at p < 0.05 and p < 0.01, respectively when comparing insulin-dependent phosphorylation of Akt and Erk1/2 between W/O pretreatment and palmitate treatment groups, statistical analysis was performed using Kruskal Wallis test and post-hoc Pairwise comparison in R. ** and *** denoted significant differences at p < 0.05, p < 0.1 and p < 0.001 when comparing Control vs Insulin, statistical analysis was performed using Student t-test.
