Figure 2.

TonEBP activation under inflammatory conditions fails to induce transcription of its canonical osmoregulatory target genes. A, schematic depicting binary TonTAD-GAL4 system used to measure TonEBP-TAD activity. B, activity of TonEBP-TAD was unaffected by treatment with TNF-α, IL-1β, or LPS alone, but it was induced by NaCl. Co-treatment with TNF-α and NaCl dampened the TAD activation by NaCl alone. C, diagram showing taurine transporter (TauT) luciferase reporter, which contains an active, highly conserved TonEBP-binding site, TonE. D, although treatment with NaCl induced activity of the TauT promoter, treatment with TNF-α, IL-1β, or LPS had no effect. E–G, TauT (E), SMIT (F), and AR (G) mRNA levels did not significantly increase with TNF-α, IL-1β, or LPS treatment for 4–24 h, whereas 8 h of NaCl treatment resulted in induction. H, co-treatment of TNF-α along with NaCl did not affect NaCl-mediated induction of TauT, SMIT, or AR. Quantitative measurements represent mean ± S.E. of ≥3 biological replicates and, for transfection experiments, 3 technical replicates per biological replicate. *, p ≤ 0.05; **, p ≤ 0.01; ***, p ≤ 0.001; ****, p ≤ 0.0001; ns, not statistically significant.