ABSTRACT
Cell adhesion molecules are crucial to many biological processes, such as cellcell and cell-substrate adhesion, and in some cases they act as regulators of intracellular signaling cascades. Adhesion molecules mediate leukocyte adhesion to endothelial, epithelial and mesangial cells and facilitate communication between cells and extracellular matrix proteins. In the kidney, the specifi c permeability and transport properties of the nephron segments are determined by the cyto-architecture of the epithelial cells and by the cell-cell and cell-matrix interactions which involve specialized junctional complexes composed of specifi c cell adhesion molecules. Disorders in the functioning of these molecules may aff ect the normal absorption/excretion of fl uid and solutes. Abundant experimental and clinical evidence indicates that adhesion molecules play a critical role in mediating the infl ammatory disease process characterized by tissue leukocyte infi ltration. Injury to the kidney triggers a cascade of events leading to changes in the expression of these molecules, conditioning the anatomical and clinical evolution of kidney disease. Th is chapter summarizes the families of adhesion molecules, including claudins, integrins, the immunoglobulin superfamily, and cadherins; their expression in normal kidney tissue; and the pathophysiological role they play in some types of kidney disease including membranous glomerulonephritis, IgA nephropathy, crescentic glomerulonephritis, glomerulosclerosis, renal cyst, acute renal failure, chronic renal failure, hemodialysis and renal transplant rejection.
