Figure 2.

Optical methods for modulating cell function using light. Three types of optical (optogenetics, photopharmacological and optochemical) approaches employed in the engineering of β-cells. (A) Light illumination stimulates PACs to upregulate conversion from ATP to intracellular cAMP thereby enhancing GSIS (See section 4.2.1). (B) Upon photoisomerization, azobenzene-based derivatives of sulfonylureas close the K_ATP⁺ channels leading to membrane depolarization, increases in [Ca²⁺]_i and eventually the secretion of insulin [92]. (C) UV radiation cleaves photo-chelator nitrophenyl-EGTA with high affinity for Ca²⁺ and decages Ca²⁺ raising [Ca²⁺]_i and leading to insulin release [99].