Reconstruction of endocrine subtype-complete human pluripotent stem cell-derived islets with capacity for hypoglycemia protection in vivo.

Summary

The authors reconstructed PSC-derived islets with all five endocrine cell types and showed that, beyond reversing hyperglycemia, these grafts markedly reduced hypoglycemia exposure in diabetic mice and restored counterregulatory responses during hypoglycemic clamps. This provides a route to tune endocrine cell proportions to enhance metabolic safety after transplantation.

Key Findings

• Engineered PSC-islets containing α, β, δ, ε, and γ cells were robustly generated in vitro.
• In diabetic mice, reconstructed PSC-islets reduced hypoglycemia exposure (3% of readings <54 mg/dL) versus non-reconstructed controls (59%).
• Hypoglycemic clamp assays indicated restoration of counterregulatory responses in recipients of reconstructed PSC-islets.

Clinical Implications

Supports development of PSC-islet products with calibrated endocrine subtype ratios to minimize post-transplant hypoglycemia risk and improve glycemic stability, informing future first-in-human trial designs and release criteria.

Limitations

• Preclinical mouse models; long-term durability and immunogenicity in large animals/humans remain unknown
• Manufacturing scalability and batch-to-batch consistency of precise endocrine ratios require validation

Future Directions

Evaluate long-term graft function and safety in large-animal models, optimize endocrine subtype ratios for specific clinical phenotypes (e.g., hypoglycemia unawareness), and define potency assays and release criteria for clinical translation.