Single-agent Foxo1 inhibition normalizes glycemia and induces gut β-like cells in streptozotocin-diabetic mice

Abstract

Insulin treatment remains the sole effective intervention for Type 1 Diabetes. Here, we investigated the therapeutic potential of converting intestinal epithelial cells to insulin-producing, glucose-responsive β-like cells by targeted inhibition of Foxo1. We have shown that this can be achieved by genetic ablation in gut Neurogenin3 progenitors, adenoviral or shRNA-mediated inhibition in human gut organoids, and chemical inhibition in Akita mice, a model of insulin-deficient diabetes. In the present study, we provide evidence that two novel Foxo1 inhibitors, FBT432 and FBT374 have glucose-lowering and gut β-like cell-inducing properties in mice rendered insulin-deficient by administration of streptozotocin. FBT432 is also highly effective in combination with a Notch inhibitor in this model. The data add to a growing body of evidence suggesting that Foxo1 inhibition be pursued as an alternative treatment to insulin administration in diabetes.

Pharmacological conversion of gut epithelial cells into insulin-producing cells lowers glycemia in diabetic animals

“…In a typical experiment, about 14% of cultured organoid cells demonstrated onset of red fluorescence following combined TGF-β/FOXO1 inhibition ( Figure 4D ). Using this screening platform, we validated several FOXO1 inhibitors (FBT) based on their potency in reporter promoter assays ( 20 ). We selected 2 compounds, FBT10 and FBT374, that outperformed AS in conversion frequency to β-like cells and Ins2 expression ( Figure 4, G and H ).…”

“…Moreover, FOXO1 inhibition using a dominant-negative mutant or lentivirus-encoded shRNA promotes generation of insulin-secreting cells in human iPSC–derived gut organoids (GOs) ( 18 ). The potential therapeutic significance of this work was amplified by recent reports: one identifying β-like cells in the human fetal intestine — and thus implying that conversion restores a fetal cell type ( 19 ); and others showing that previously described small molecule FOXO1 inhibitors can yield insulin-producing cells in vivo and lower glycemia in diabetic mice ( 20 , 21 ). These findings prompted us to investigate whether other descendants of Neurog3 + progenitors, such as subsets of goblet and Paneth cells, have the potential to be converted into insulin-secreting β-like cells.…”

“…4D). Using this screening platform, we validated several new novel FOXO1 inhibitors (FBT) based on their potency in reporter promoter assays (20) . We selected two compounds, FBT10 and FBT374, that outperformed AS in conversion frequency to -like cells and Ins2 expression (Fig.…”

“…To evaluate the translational value of this triple combination therapy in an autoimmune model of diabetes, we used Repsox and the gamma secretase inhibitor PF-03084014, currently in Phase II for the treatment of different forms of cancer (36), in combination with the chemical FOXO1 inhibitor, FBT10 (20,21). 5 days of oral administration with FBT10, PF, and Repsox only slightly decreased body weight (Fig 6B ), with a significant increase of plasma insulin and GLP1 levels (Fig 6C , D).…”