Loperamide counters FoxO inhibition in different model systems.A. Overview of C. elegans development in favorable or unfavorable environmental conditions. B. Effects of FoxOi and loperamide treatment on the FOXO-dependent developmental process of Dauer formation in C. elegans. Eggs of CB1370 animals were hedged and grown at 23 °C (left panel) or 22 °C (right panel) in the presence of FoxOi or loperamide at the indicated concentrations. In the absence of compounds (0 μM), the fraction of animals forming Dauer was 20.2% (left panel) and 3.2% (right panel). Compound-induced fold changes of this fraction are shown. N = 3; 100 animals per condition and replicate. C. Representative images of developmental defects in zebrafish larvae following 48h FoxOi treatment and rescue with loperamide. D. Quantification of insulin or glucagon-positive cells following loperamide treatment in zebrafish larvae. Ncontrol = 12; Nloperamide = 21. E. Representative images of pancreatic human islets stained for insulin and glucagon. Scale bars = 10 μm. On the right: Summary of the population distribution change in the human islets. F. Measurement of INS and GCG transcription in human islets treated with loperamide by RT-qPCR. All the data points are normalized to DMSO control, n = 4. G. Transcription of GCG, INS, and PDX1 in pancreatic islets from human diabetic donors treated for 48h with loperamide, as measured by RT-qPCR, n = 2. H. Glucose-stimulated insulin secretion assay on diabetic human islets pretreated with loperamide for 48 h, n = 2. Basal = 0.3 g/L glucose; stimulated = 3 g/L glucose. I. Relative insulin and Pdx1 mRNA levels in islets from db/db mice pretreated with loperamide for 48h.
