Fig. 5

Insulin and C-peptide synthesis by generated insulin producing cells. a Doxycycline-regulated Pdx1 and Nkx6.1 expression. iPSC lines with stably integrated Pdx1 and Nkx6.1 transgenes under control of Tre3G promoter were induced by addition of doxycycline and stained with antibodies against Pdx1 and Nkx6.1. The negative control were iPS cells that were not treated with doxycycline. Scale bar 100 µm. b Insulin secretion in response to 2.5 mM glucose concentration after transgenes induction at selected steps of the differentiation procedure. Results of the ELISA were normalized to the total protein concentration and presented as picograms of produced insulin per milligram of the total protein content of insulin secreting cells. Control includes cells without introduced transgenes. Asterisk indicate statistically relevant difference between compared samples. c Immunocytochemical detection of insulin and C-peptide production in cells where transgene expression was switched on at indicated stages of differentiation. Scale bar 20 µm