Translational Factor eIF4G1 Regulates Glucose Homeostasis and Pancreatic β-Cell Function

Area of Science:

• Molecular Biology
• Endocrinology
• Metabolic Disease Research

Background:

• Protein translation is vital for cell function, and its dysregulation is linked to aging-related diseases like type 2 diabetes.
• Reduced levels of the translation initiation factor eIF4G1 are associated with diabetes in humans and mice.

Purpose of the Study:

• To investigate the critical role of eIF4G1 in pancreatic beta-cell function and glucose homeostasis.
• To determine the effects of specifically ablating eIF4G1 in beta-cells in vivo.

Main Methods:

• Generation of mice with genetic ablation of eIF4G1 specifically in beta-cells (βeIF4G1KO).
• Assessment of glucose tolerance, insulin sensitivity, beta-cell mass, proliferation, and apoptosis.
• Analysis of insulin secretion, mitochondrial function, calcium flux, and eIF4E levels.

Main Results:

• βeIF4G1KO mice exhibited glucose intolerance but normal insulin sensitivity.
• Beta-cell proliferation and apoptosis increased, while beta-cell mass remained normal.
• Insulin secretion deficits were linked to reduced mitochondrial respiration, impaired calcium flux, and decreased eIF4E, impacting insulin biosynthesis.

Conclusions:

• The translational factor eIF4G1 is essential for maintaining beta-cell function and glucose homeostasis.
• Loss of eIF4G1 affects insulin biosynthesis through its interaction with eIF4E.
• These findings underscore the importance of eIF4G1 in metabolic regulation and suggest potential therapeutic targets for diabetes.