Fig. 6.

LP-CS stimulates SMCT1 promoter activity and attenuates TNF-α inhibition of SMCT1 function and promoter activity. A: postconfluent IEC-6 monolayers were pretreated with LP-CS from the apical surface for 8 h, which was continued for another 16 h, with and without TNF-α (10 ng/ml) added basolaterally. Na⁺-dependent ¹⁴C-butyrate uptake was then measured. B: Caco-2 cells were transfected with the SMCT1 promoter construct in pGL2. Twenty-four hours after transfection, cells were pretreated with LP-CS from the apical surface for 8 h, which was continued for another 16 h, with and without TNF-α (10 ng/ml) added basolaterally. Promoter activity was measured as luciferase units and normalized with the corresponding β-galactosidase units for transfection efficiency. Values are means ± SE; n = 4. *Different from control, P < 0.001.