Figure 6: Co-Exposure to T3 Inhibits Dust-Induced Triglyceride Accumulation.

3T3-L1 cells were induced to differentiate as described in Methods. Cells were assessed for degree of adipocyte differentiation after ten days of differentiation while exposed to set concentrations of nine select indoor house dust extracts either alone or co-treated with 10 μM T3. (A, B) Raw triglyceride accumulation per well relative to maximal response for rosiglitazone, (C, D) increase (pre-adipocyte proliferation) in DNA content relative to vehicle control, and (E, F) percent normalized triglyceride accumulation per cell relative to maximal rosiglitazone response (normalized to DNA content). Two concentrations were examined for each dust extract. The left column depicts low-dose concentrations that were 16-fold dilutions of the maximal concentrations for each extract (A, C, E). The right column depicts high-dose concentrations tested were the maximal concentration of each extract and varied depending on the quantity of dust collected in each household (B, D, F). The left bar in each pair depicts the response induced by the dust extract alone, while the right bar in each pair depicts the activity induced by the dust extract co-treated with T3. Data presented as mean ± SEM from two independent experiments of four biological replicates. # = p < 0.10, * = p < 0.05, ** = p < 0.01 indicate statistical differences between T3/dust co-treatment and dust samples alone as per one-way ANOVA and Dunnett’s posthoc test in GraphPad Prism 7.0.