Triple Notch/Tgfβ/FoxO1 blockade converts multiple intestinal sub-lineages into β-like cells and lowers glycemia in diabetic animals

Type 1 Diabetes requires lifelong insulin replacement. Replenishing β-cells by transplantation or cell conversion can provide a more durable treatment. Enteroendocrine cells can be converted into insulin-producing cells, but their numbers are limited. We report that insulin-immunoreactive cells with Paneth/goblet cell features are present in human fetal intestine, in addition to enteroendocrine cells. Accordingly, lineage-tracing experiments show that, besides enteroendocrine cells, the Paneth/goblet lineage can undergo conversion to the insulin lineage upon FoxO1 ablation. We designed a screening platform in organoids to accurately quantitate β-like cell reprogramming by small-molecule agents and increase the efficiency of the conversion process by expanding the intestinal secretory lineage. We show that triple blockade of FoxO1, Notch, and Tgfβ, when tested in insulin-deficient diabetic animals, results in a near-normalization of glucose levels, associated with the appearance of gut insulin-producing cells. The findings illustrate a therapeutic approach to replace insulin treatment in diabetes. ### Competing Interest Statement DA was a founder, director, and chair of the advisory board of Forkhead Biotherapeutics. Y.L. and S.B. performed this work as employees of Forkhead Biotherapeutics.