An insulin hypersecretion phenotype precedes pancreatic 13 cell failure in MODY3 patient-specific cells

MODY3 is a monogenic hereditary form of diabetes caused by mutations in the transcription factor HNF1A. The patients progressively develop hyperglycemia due to perturbed insulin secretion, but the pathogenesis is unknown. Using patient-specific hiPSCs, we recapitulate the insulin secretion sensitivity to the membrane depolarizing agent sulfonylurea commonly observed in MODY3 patients. Unexpectedly, MODY3 patient -specific HNF1A+/R272C R cells hypersecrete insulin both in vitro and in vivo after transplantation into mice. Consistently, we identified a trend of increased birth weight in human HNF1A mutation carriers compared with healthy siblings. Reduced expression of potassium channels, specifically the KATP channel, in MODY3 0 cells, increased calcium signaling, and rescue of the insulin hypersecretion phenotype by pharmacological targeting ATP-sensitive potassium channels or low-voltage-activated calcium channels suggest that more efficient membrane depolarization underlies the hypersecretion of insulin in MODY3 0 cells. Our findings identify a pathogenic mechanism leading to 0 cell failure in MODY3.

Automated summary

MODY3 is a monogenic form of diabetes caused by HNF1A mutations, leading to perturbed insulin secretion. Using hiPSCs, we found that MODY3 cells hypersecrete insulin both in vitro and in vivo. Our findings suggest that the hypersecretion of insulin in MODY3 cells is due to more efficient membrane depolarization.