PepT1-mediated tripeptide KPV uptake reduces intestinal inflammation

This study revealed the molecular mechanism by which the tripeptide KPV (Lys-Pro-Val), derived from the alpha-MSH hormone, exerts its anti-inflammatory effects in the gastrointestinal tract. The researchers demonstrated that KPV is transported into intestinal epithelial cells by the peptide transporter PepT1, a fundamental mechanism for its oral bioavailability.

Using murine models of colitis induced by DSS (dextran sodium sulfate) and TNBS (trinitrobenzenesulfonic acid), the study showed that oral administration of KPV:

• Significantly reduced the incidence and severity of colitis
• Decreased the production of pro-inflammatory cytokines (TNF-α, IL-6, IL-12)
• Inhibited NF-κB activation in intestinal epithelial and immune cells
• Protected epithelial barrier integrity

A particularly elegant finding was the demonstration that the anti-inflammatory effect of KPV was abolished in PepT1-deficient cells, confirming that this transporter is essential for peptide action. This has important practical implications, as PepT1 is highly expressed in the small intestine.

This work established the foundation for oral use of KPV as a therapeutic agent for inflammatory bowel diseases, offering a more targeted approach with fewer systemic effects than conventional immunosuppressants.