A Lysozyme-Derived Peptide Induces GLP-1 Secretion in Mouse Jejunal Organoids and Modulates Glycemia in Rats

Area of Science:

• Biochemistry
• Endocrinology
• Nutritional Science

Background:

• Protein digestion products stimulate incretin release, crucial for glucose homeostasis.
• Previous research indicated egg white peptides promote GLP-1 secretion in STC-1 cells.

Purpose of the Study:

• To evaluate GLP-1 secretion induced by a lysozyme-derived peptide (¹²³WIRGCRL¹²⁹) and its analogues.
• To compare the peptide's efficacy with egg white digest and phenylalanine (Phe) in mouse jejunal organoids and STC-1 cells.
• To investigate the therapeutic potential of food-derived peptides in managing type 2 diabetes.

Main Methods:

• GLP-1 secretion was measured in mouse jejunal organoids and STC-1 cells.
• The study utilized a specific peptide (¹²³WIRGCRL¹²⁹), its analogues, egg white digest, and phenylalanine.
• Oral glucose tolerance tests were performed in Wistar rats.

Main Results:

• The peptide ¹²³WIRGCRL¹²⁹ induced significant GLP-1 release in both organoids and cell lines, comparable to or exceeding Phe at lower concentrations.
• ERK and AMPK pathways were implicated in the peptide-induced GLP-1 secretion in STC-1 cells.
• Oral administration of the peptide in rats reduced glucose levels, unlike an equimolar amino acid mixture.

Conclusions:

• The lysozyme-derived peptide ¹²³WIRGCRL¹²⁹ demonstrates potent GLP-1 stimulating activity.
• This peptide shows promise as a potential therapeutic agent for type 2 diabetes.
• Food-derived peptides represent a viable strategy for glucose regulation and diabetes treatment.