Single-cell RNAseq of mouse pancreatic cells treated with proliferative compounds

It is known that β-cell proliferation expands the β-cell mass during development and under certain hyperglycemic conditions in the adult, a process that may be used for β-cell regeneration in diabetes. Here we used a novel high-throughput technique in zebrafish and screened 3119 chemicals to determine whether they promoted β-cell proliferation. We identified HG-9-91-01, which was further confirmed to drive the proliferation of zebrafish, mouse, and human β-cells. HG-9-91-01 is an inhibitor of salt-inducible kinases (SIK), and β-cell specific overexpression of Sik1 blocked its effect on β-cell proliferation. Single-cell transcriptomic analyses of mouse β-cells demonstrated that HG-9-91-01 induced an early wave of ATF6-dependent unfolded protein response (UPR), which was not related to increased insulin expression. Additional mechanistic studies indicated that HG-9-91-01 induced multiple signaling effectors downstream of SIK inhibition, including CRTC, ATF6/IRE1, and mTOR, which integrated to collectively drive β-cell proliferation. Examination of six 384-well plates corresponding to pancreatic mouse enocrine cells treated for 6, 48 or 96 h with different compounds. Plate layout was as follows: single-cells treated with negative control DMSO (96 wells), positive control Harmine (96 wells) and with one of the other compounds (96 wells per compound) at a specific time point.