Minimizing Mitogenic Potency of Insulin Analogues Through Modification of a Disulfide Bond

Area of Science:

• Biochemistry
• Molecular Biology
• Endocrinology

Background:

• Insulin receptor activation mechanisms for metabolic and growth signaling remain unclear.
• Structural studies have advanced understanding of insulin binding but not signaling bias.
• Few insulin receptor agonists exhibit biased signaling properties.

Purpose of the Study:

• To investigate the mechanisms underlying insulin signaling bias using novel insulin analogs.
• To explore how modifications at the insulin A6-A11 bond influence receptor activation and downstream signaling.
• To develop insulin analogs with reduced mitogenic activity for safer diabetes treatment.

Main Methods:

• Synthesis of novel insulin analogs with a rigid, non-reducible C=C (dicarba) linkage at the A6-A11 bond.
• Comparison of signaling properties between native insulin, insulin glargine, and their dicarba bond modified counterparts.
• Assessment of insulin receptor activation, internalization, and downstream metabolic and mitogenic signaling pathways.

Main Results:

• Introduction of an A6-A11 cis-dicarba bond into insulin or insulin glargine resulted in biased signaling analogs.
• These modified insulins exhibited significantly reduced mitogenic potency.
• Reduced insulin receptor activation and impaired receptor internalization were observed, correlating with lower mitogenic signaling.

Conclusions:

• The A6-A11 dicarba bond modification is a viable strategy to achieve biased insulin signaling.
• This modification leads to insulin analogs with low mitogenic activity, potentially reducing cancer risk associated with long-term insulin therapy.
• Further development of such analogs could lead to safer and more effective treatments for diabetes.