ENDOTHELIAL AND EPITHELIAL-CELL ADHESION MOLECULES

This review will discuss a number of specific cell adhesion molecules present on the surface of endothelial and epithelial cells in the lung. Molecules such as integrins, proteoglycans, and the hyaluronic acid receptor, CD44, are found on the abluminal or basement membrane side of the cell and function as cell-substratum receptors. Cadherins, integrins, and platelet-endothelial cell adhesion molecule-1 (PECAM-1) are present at the cell-cell borders of adjacent endothelial and/or epithelial cells and function to initiate or maintain cell-cell adhesion. Finally, a number of inducible cell adhesion molecules such as endothelial-leukocyte adhesion molecule-1 (ELAM-1), granule-associated membrane protein 140 (GMP140), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) are expressed on the luminal surfaces of these cells during inflammation and function as cell-cell adhesion molecules important in white blood cell, platelet, or tumor cell adhesion. These adhesion molecules likely play important roles in maintaining the normal structure and function of the lung, as well as participating in pulmonary processes such as inflammation, wound healing, and the development and spread of malignant disease.