In situ pharmacological induction of pancreatic beta-cell regeneration by THR-123, a cyclic peptide with BMP-7-like activity

The demonstration that BMP signaling activates progenitor-like populations within pancreatic ducts supports the potential use of BMP receptor agonists to induce islet regeneration in situ. In this context, we tested the ability of THR-123, a cyclic peptide with BMP-7-like activity, to restore b-cell mass in diabetic mice. Here we show that treatment with THR-123 restores normoglycemia through the rapid formation of new BrdU-labeled islets in the vicinity of ducts. Neogenic islets, unlike those from non-diabetic controls, feature an extensive intrainsular network of ductal tissue. The earlier stages of THR-123-induced b-cell neogenesis were reproduced in live pancreatic slices, an organotypic model that allowed us to visualize ductal cells transitioning to glucose-responsive insulin-expressing cells in real time. scRNAseq analyses further confirmed that this transition occurs through a hybrid ducto-acinar stage similar to that previously reported in humans. These results pave the way to the design of pharmacological strategies to treat insulin-dependent diabetes. Overall design: We conducted scRNAseq analysis of murine pancreatic slices generated from either non-diabetic or alloxan-induced diabetic mice. mPSs (n=6) from non-diabetic mice were sequenced after 5 days of culture (positive control). Slices from diabetic mice were either treated with THR-123 for 5 days (experimental group) or left untreated for the same period (alloxan, negative control) prior to sequencing. The experiment was repeated three times, and cells pooled for each of the three groups. In total, ~32,000 single cells were analyzed using the 10X Genomics 5' Single Cell platform. Libraries were filtered for quality control and subjected to unsupervised clustering, integration and differential gene expression analysis using Seurat v4.1.1. We analyzed individual datasets as well as the integration of the alloxan (negative) control and the THR-123 (experimental) datasets to perform dynamic RNA velocity studies. additional grants 1R01DK130846-01 and U01DK120393: Juan Dominguez-Bendala and Ricardo L Pastori