SUR1-mutant iPS cell-derived islets recapitulate the pathophysiology of congenital hyperinsulinism

Abstract

Aims/hypothesis Congenital hyperinsulinism caused by mutations in the K ATP-channel-encoding genes (K ATP HI) is a potentially life-threatening disorder of the pancreatic beta cells. No optimal medical treatment is available for patients with diazoxideunresponsive diffuse K ATP HI. Therefore, we aimed to create a model of K ATP HI using patient induced pluripotent stem cell (iPSC)-derived islets. Methods We derived iPSCs from a patient carrying a homozygous ABCC8 V187D mutation, which inactivates the sulfonylurea receptor 1 (SUR1) subunit of the K ATP-channel. CRISPR-Cas9 mutation-corrected iPSCs were used as controls. Both were differentiated to stem cell-derived islet-like clusters (SC-islets) and implanted into NOD-SCID gamma mice. Results SUR1-mutant and-corrected iPSC lines both differentiated towards the endocrine lineage, but SUR1-mutant stem cells generated 32% more beta-like cells (SC-beta cells) (64.6% vs 49.0%, p = 0.02) and 26% fewer alpha-like cells (16.1% vs 21.8% p = 0.01). SUR1-mutant SC-beta cells were 61% more proliferative (1.23% vs 0.76%, p = 0.006), and this phenotype could be induced in SUR1-corrected cells with pharmacological K ATP-channel inactivation. The SUR1-mutant SC-islets secreted 3.2-fold more insulin in low glucose conditions (0.0174% vs 0.0054%/min, p = 0.0021) and did not respond to K ATP-channel-acting drugs in vitro. Mice carrying grafts of SUR1-mutant SC-islets presented with 38% lower fasting blood glucose (4.8 vs 7.7 mmol/l, p = 0.009) and their grafts failed to efficiently shut down insulin secretion during induced hypoglycaemia. Explanted SUR1-mutant grafts displayed an increase in SC-beta cell proportion and SC-beta cell nucleomegaly, which was independent of proliferation. Conclusions/interpretation We have created a model recapitulating the known pathophysiology of K ATP HI both in vitro and in vivo. We have also identified a novel role for K ATP-channel activity during human islet development. This model will enable further studies for the improved understanding and clinical management of K ATP HI without the need for primary patient tissue. Keywords Beta cells. Congenital hyperinsulinism. Disease modelling. Induced pluripotent stem cells. K ATP-channel. Pancreatic islet development. Stem cell-derived islets Abbreviations CHI Congenital hyperinsulinism CXCR4 C-X-C motif chemokine receptor 4 GBC Glibenclamide iPSC Induced pluripotent stem cell K ATP HI Congenital hyperinsulinism due to loss-of-function of the K ATP channel PDX1 Pancreatic and duodenal homeobox 1 RNP Ribonucleoprotein SC-alpha cell Stem cell-derived alpha-like cell * Väinö Lithovius

Stem Cell-Derived β Cells: A Versatile Research Platform to Interrogate the Genetic Basis of β Cell Dysfunction

“…Other described iPSC lines were generated from patients with mutations in GCK [ 144 ], PDX1 [ 13 , 155 ], KCNJ11 [ 156 ], INS [ 157 , 158 ], YIPF5 [ 159 ], GATA6 [ 160 ], WFS1 [ 161 , 162 ], TRMT10A [ 163 ], ONECUT [ 136 ], FOXA2 [ 164 ] and activating mutations in STAT3 [ 165 ]. Patient-derived iPSCs were also used to model congenital hyperinsulinism caused by ABCC8 deficiency [ 166 ].…”

Stem Cell Based Models in Congenital Hyperinsulinism – Perspective on Practicalities and Possibilities

“…Thus far, two studies have taken advantage of the SC-islet differentiation and genome editing technologies in modeling K ATP -channel related CHI (K ATP HI) (36,37), as summarized in Table 1. Guo and colleagues (36), used healthy hESCs and introduced a knockout of the ABCC8 gene, encoding the K ATPchannel subunit SUR1.…”

“…We used iPSCs derived from a patient carrying the homozygous V187D-mutation (38) in the ABCC8 gene and compared them to mutation-corrected controls (37). The ABCC8 mutant beta-like cells secreted around 3-fold more insulin in low glucose compared to the corrected counterparts.…”

Genome Editing Human Pluripotent Stem Cells to Model β-Cell Disease and Unmask Novel Genetic Modifiers

“…The first lab-guided hPSC differentiation protocols were developed to generate definitive endoderm (50), followed quickly by protocols capable of driving hPSCs towards pancreatic progenitors and endocrine cells (51). While these protocols initially required that pancreatic progenitors be transplanted into mice to mature into functional b-cells, current protocols can achieve functionality in vitro without transplantation (52)(53)(54) This field has become robust with technical advancements being published regularly by laboratories around the world, resulting in the generation of blike cells that are closer and closer to their natural counterparts, though continued optimization of functionality is required (55)(56)(57)(58)(59)(60)(61)(62).…”