Light-Mediated Insulin and Amylin Secretion: Influence of Irradiation Parameters in Optogenetically Modified Mouse-Pancreatic β Cells.

Optogenetics offers a promising avenue for controlled insulin secretion in diabetes management using genetically modified cells. However, the influence of irradiation parameters on the co-secreted hormone amylin remains largely unexplored. This study examined how blue light power densities (50, 100, and 200 mW/cm²) under continuous and intermittent exposure affect hormonal secretion in channelrhodopsin-2 expressing mouse β cells. Results showed that 10 s of continuous exposure at 50 mW/cm² increased insulin and amylin secretion by ~25% and 40%, respectively. Introducing intermittent dark intervals further enhanced secretion by ~35% for insulin and 70% for amylin at 50 and 100 mW/cm² respectively, correlating with intracellular calcium changes. Notably, light modulated the amylin-to-insulin molar ratio, peaking with a 34% increase during 5 s 'on'-10s 'off' exposure at 100 mW/cm². This study provides the first evidence that light irradiation parameters can differentially influence hormonal secretion from engineered cells, offering a potential for tailored cell-based diabetes therapies.