Single-cell transcriptomes identify human islet cell signatures and reveal cell-type-specific expression changes in...

Area of Science:

• Endocrinology
• Molecular Biology
• Genomics

Background:

• Pancreatic islets regulate blood glucose via four main cell types.
• Cellular heterogeneity complicates understanding islet cell function, especially delta and PP/gamma cells.
• Islet cell dysfunction is linked to diabetes pathophysiology.

Purpose of the Study:

• To characterize cell-type-specific transcriptomes in human pancreatic islets.
• To identify molecular differences between nondiabetic (ND) and type 2 diabetic (T2D) islet cells.
• To elucidate the role of delta cells in integrating metabolic signals.

Main Methods:

• Single-cell RNA sequencing of 638 cells from human islet samples (ND and T2D).
• Bioinformatic analysis to identify cell-type signatures and differentially expressed genes.
• Comparative analysis between ND and T2D islet cells.

Main Results:

• Distinct transcriptomic signatures identified for alpha, beta, delta, and PP/gamma cells in ND islets.
• Genes associated with diabetes were found in delta and PP/gamma cells.
• Delta cells express receptors for leptin, ghrelin, and dopamine, suggesting a role in integrating systemic signals.
• Differential gene regulation between T2D and ND alpha, beta, and delta cells was observed, missed in whole-islet analysis.

Conclusions:

• This study provides a detailed cell-type-specific map of human islet transcriptomes.
• Identifies novel cell-type-specific molecular features critical for islet function and diabetes.
• Highlights delta cells as key integrators of metabolic and hormonal cues.