Engineering a Rapid Insulin Release System Controlled By Oral Drug Administration.

Area of Science:

• Biotechnology
• Endocrinology
• Molecular Biology

Background:

• Maintaining blood-glucose homeostasis is crucial, with type-1 diabetes mellitus (T1DM) requiring lifelong insulin therapy.
• Current insulin delivery methods, primarily injections, present challenges in patient compliance and quality of life.
• Development of advanced, less invasive insulin delivery systems is essential for T1DM management.

Purpose of the Study:

• To engineer a novel rapamycin-actuated protein-induction device (RAPID) for controlled, rapid insulin secretion.
• To establish a cell-based system for on-demand biopharmaceutical release.
• To investigate the potential of RAPID as a therapeutic strategy for T1DM.

Main Methods:

• Engineered an endoplasmic-reticulum-localized split sec-tobacco etch virus protease (TEVp)-based RAPID system.
• Fused rapamycin-inducible dimerization domains (FKBP and FKBP-rapamycin binding protein) with split sec-TEVp components.
• Utilized KDEL ER-retention signal and TEVp cleavage site for insulin accumulation and regulated release.
• Employed liver hydrodynamic transfection in T1DM mice for in vivo validation.

Main Results:

• The RAPID system demonstrated rapamycin-inducible dimerization and regained proteolytic activity.
• Upon rapamycin administration, the KDEL retention signal was cleaved, leading to rapid insulin secretion within minutes.
• In T1DM mice, RAPID successfully restored glucose homeostasis following oral rapamycin treatment.
• The engineered system showed rapid biopharmaceutical availability.

Conclusions:

• The developed RAPID system enables rapid, controllable insulin secretion, addressing a critical need in T1DM therapy.
• This technology offers a promising, less invasive alternative to conventional insulin injections.
• The RAPID platform has the potential to be foundational for other cell-based therapies requiring rapid biopharmaceutical release.