Optical Control of Insulin Secretion Using an Incretin Switch

Area of Science:

• Biochemistry
• Pharmacology
• Endocrinology

Background:

• Incretin mimetics are crucial for type 2 diabetes management, enhancing insulin secretion and promoting weight loss.
• Current incretin therapies can cause gastrointestinal side effects like nausea.
• Targeting the glucagon-like peptide-1 receptor (GLP-1R) is a key strategy in diabetes treatment.

Purpose of the Study:

• To design and synthesize a novel photoswitchable incretin mimetic for precise control over GLP-1R signaling.
• To investigate the isomer-specific activation of second messenger pathways by the new compound.
• To explore the potential of light-controlled incretin therapy for type 2 diabetes.

Main Methods:

• Design and synthesis of a photoswitchable peptidic compound (LirAzo) incorporating an azobenzene photoresponsive element.
• Testing LirAzo's interaction with the glucagon-like peptide-1 receptor (GLP-1R).
• Analysis of differential second messenger pathway activation (calcium influx vs. cAMP generation) in response to light-induced isomerisation.

Main Results:

• LirAzo, a photoswitchable GLP-1R agonist, was successfully synthesized.
• Light exposure induced isomerisation of LirAzo, leading to distinct signaling outcomes.
• The trans isomer of LirAzo primarily activated calcium influx, while the cis isomer favored cAMP generation.

Conclusions:

• LirAzo enables optical control over GLP-1R signaling, offering a novel approach to diabetes therapy.
• Isomer-biased signaling provides a mechanism for fine-tuning insulin secretion and cell survival.
• This photoswitchable incretin mimetic holds promise for developing targeted and potentially side-effect-reduced diabetes treatments.