Engineering a glucose-responsive human insulin-secreting cell line from islets of langerhans isolated from a patient with persistent hyperinsulinemic hypoglycemia of infancy

Persistent hyperinsulinemic hypoglycemia of infancy (PHHI) is a neonatal disease characterized by dysregulation of insulin secretion accompanied by profound hypoglycemia, We have discovered that islet cells, isolated from the pancreas of a PHHI patient, proliferate in culture while maintaining a beta cell-like phenotype, The PHHI-derived cell line (NES2Y) exhibits insulin secretory characteristics typical of islet cells derived from these patients, i,e, they have no K-ATP channel activity and as a consequence secrete insulin at constitutively high levels in the absence of glucose, In addition, they exhibit impaired expression of the homeodomain transcription factor PDX1, which is a key component of the signaling pathway linking nutrient metabolism to the regulation of insulin gene expression. To repair these defects NES2Y cells were triple-transfected with cDNAs encoding the two components of the K-ATP channel (SUR1 and Kir6.2) and PDX1, One selected clonal cell line (NISK9) had normal K-ATP channel activity, and as a result of changes in intracellular Ca2+ homeostasis ([Ca2+](i)) secreted insulin within the physiological range of glucose concentrations. This approach to engineering PHHI-derived islet cells may be of use in gene therapy for PHHI and in cell engineering techniques for administering insulin for the treatment of diabetes mellitus.