Figure 1

Effect of ER stress preconditioning on intracellular Hg content and on the expression of membrane transporters following exposure to MeHg. (A) Time course study of intracellular Hg content. C2C12-DMPK160 cells pretreated with TPG (0.3 μg/ml) for 16 h were exposed to 0.5 μM MeHg. Values represent the means ± SE (n = 3). ^{#, ##}Significantly different from TPG-untreated cells by a one-way Welch’s t-test (^#p < 0.05, ^##p < 0.01). (B) Changes in the expression of mRNA following exposure to MeHg. Total RNA was extracted from cells treated with 0.5, 0.8, or 1.0 μM MeHg for 5 or 7 h and membrane transporter mRNA expression was analyzed by RT-qPCR. The histogram depicts the indicated mRNA normalized to Actb mRNA. Values shown are the means ± SE of 3 separate experiments. *^, ***Significantly different from MeHg-untreated cells by a one-way ANOVA (*p < 0.05, ***p < 0.001). (C,D) Expression of membrane transporter (C) or the alternative ABCC4 splice-form (Abcc4s) (D) mRNA was analyzed at the times indicated after the exposure to 0.5 μM MeHg using RT-qPCR. The histogram depicts the indicated mRNA normalized to Actb mRNA. Values shown are the means ± SE of 3 separate experiments. *^, **^, ***Significantly different from TPG- and MeHg-untreated cells by a one-way ANOVA (*p < 0.05, **p < 0.01, ***p < 0.001). (E) Western blotting analyses of membrane transporter expression. Total cell lysates prepared at the times indicated were analyzed using the indicated antibody probes. Cropped blots are shown; all gels were run under the same experimental conditions.