Characterization of protease-activated receptor-2 immunoreactivity in normal human tissues

J Histochem Cytochem. 1998 Feb;46(2):157-64. doi: 10.1177/002215549804600204.


PAR-2 is a second member of a novel family of G-protein-coupled receptors characterized by a proteolytic cleavage of the amino terminus, thus exposing a tethered peptide ligand that autoactivates the receptor. The physiological and/or pathological role(s) of PAR-2 are still unknown. This study provides tissue-specific cellular localization of PAR-2 in normal human tissues by immunohistochemical techniques. A polyclonal antibody, PAR-2C, was raised against a peptide corresponding to the amino terminal sequence SLIGKVDGTSHVTGKGV of human PAR-2. Significant PAR-2 immunoreactivity was detected in smooth muscle of vascular and nonvascular origin and stromal cells from a variety of tissues. PAR-2 was also present in endothelial and epithelial cells independent of tissue type. Strong immunolabeling was observed throughout the gastrointestinal tract, indicating a possible function for PAR-2 in this system. In the CNS, PAR-2 was localized to many astrocytes and neurons, suggesting involvement of PAR-2 in neuronal function. A role for PAR-2 in the skin was further supported by its immunolocalization in the epidermis. PAR-2C antibody exemplifies an important tool to address the physiological role(s) of PAR-2.

MeSH terms

  • Amino Acid Sequence
  • Antibody Specificity
  • Blood Platelets / chemistry
  • Brain Chemistry*
  • Cells, Cultured
  • Digestive System / chemistry*
  • Endothelium / chemistry
  • Endothelium / cytology
  • Epidermis / chemistry*
  • Epithelial Cells / chemistry*
  • Humans
  • Immunohistochemistry
  • Molecular Sequence Data
  • Muscle, Smooth / chemistry*
  • Neurons / chemistry
  • Organ Specificity
  • Receptor, PAR-2
  • Receptors, Cell Surface / analysis*
  • Receptors, Cell Surface / immunology
  • Stromal Cells / chemistry


  • Receptor, PAR-2
  • Receptors, Cell Surface