The Expression of Protease-Activated Receptor 2 and 4 in the Colon of Irritable Bowel Syndrome Patients

Background Irritable bowel syndrome (IBS) pathophysiology has not been fully understood. Abnormalities of serine proteases have been identified in IBS patients. In addition, protease-activated receptors (PAR) activation interferes with several components of the pathogenesis of IBS, so, evaluating the PAR expression in IBS patients may contribute to understanding the pathogenesis of the disease. Aims This study aimed to investigate whether the expression of PAR4 and PAR2 in the colon was changed in IBS patients and was associated with IBS. Methods Colon mucosal biopsies of 34 IBS patients (16 constipation- and 18 diarrhea-predominant) and 18 control subjects were collected. Gene transcripts of PAR2, PAR4, tryptase, and trypsin were quantified using real-time polymerase chain reaction (PCR) and the expression of PAR2 and PAR4 receptors was also measured by immunohistology and image analysis. Results In IBS patients, the mRNA expression of tryptase and trypsin normalized against β-actin gene was higher compared to control subjects ( P