Protease activated receptor 2: a new target for IBS treatment

Area of Science:

• Gastroenterology
• Molecular Biology
• Neuroscience

Background:

• Proteinase-activated receptors (PARs) are G-protein-coupled receptors activated by proteolytic cleavage.
• PAR-2 is abundant in the gastrointestinal tract, involved in functions like motility, secretion, and pain signaling.
• Luminal proteases, including trypsin and bacterial proteases, can activate PAR-2 in the gut.

Purpose of the Study:

• To investigate the role of PAR-2 activation by luminal proteases in visceral pain and gut hypersensitivity.
• To explore the potential of targeting PAR-2 or luminal proteases for treating conditions like irritable bowel syndrome (IBS).

Main Methods:

• Administering PAR-2 agonists (SLIGRL, trypsin) intracolonically in rats to assess effects on colonic distension sensitivity.
• Measuring colonic paracellular permeability and evaluating the impact of PAR-2 blockade.
• Analyzing stool supernatants from IBS patients for protease activity and their effects in mice.

Main Results:

• Intracolonic PAR-2 activation in rats induced delayed hypersensitivity to colonic distension, mediated locally.
• This hypersensitivity was linked to increased colonic paracellular permeability.
• Stool supernatants from diarrhea-predominant IBS patients exhibited serine-protease activity that caused permeability and hypersensitivity in mice via PAR-2 activation.

Conclusions:

• Luminal protease activation of PAR-2 contributes to gut hypersensitivity and visceral pain.
• Increased colonic permeability and immune system activation are key mechanisms.
• PAR-2 and luminal proteases represent potential therapeutic targets for IBS and related gut disorders.