Fig. 1

Factors secreted by RENCA macrobeads alter the transcription factor activity and expression of MEF2. (a) RENCA cells, transiently transfected with pathway-focused transcription factor-responsive luciferase reporter constructs were exposed to naïve media or 5-day conditioned media from > 18 wk. RENCA macrobeads. Fold-change, calculated based on normalized luciferase activity of the conditioned media (CM) response relative to the naïve media response, is graphed in descending order. Columns, mean (n = 3); bar, SD. Dotted lines at 2 and 0.5 on the y-axis indicate the threshold for two-fold up- and down-regulation respectively. (b) MEF2 reporter activity in RENCA cells exposed to 5-day RENCA macrobead-conditioned media. Reporter activity in response to naïve media was used as a control. Fold-change was calculated for each sample relative to the naïve media sample. Each column represents the mean (n = 6–8) ± SD (primary axis). Mean inhibitory response of RENCA macrobeads on freely growing RENCA cells; red circles (n = 3) ± SD (secondary axis). (c) RENCA cells were co-cultured with > 18 wk. RENCA macrobeads for 5 days. RENCA cells cultured in naïve media served as a control. Total RNA was isolated and subjected to real-time PCR analysis for the expression of MEF2a, MEF2b, MEF2c and MEF2d. MEF2c was not detected in RENCA cells. Each column represents the mean (n = 3) ± SD. *p < 0.001, compared with naïve media