Cyclins and the cyclin-kinase system--their potential roles in nephrology.

Our understanding of the cell-cycle mechanisms has progressively advanced in the past few years. Cyclins and cyclin-dependent kinases play major roles as positive cell-cycle regulatory proteins and CDK inhibitors; while the Kip family and INK4 family are negative regulatory proteins in mesangial cells and renal tubular cells. An understanding of the cell cycle is essential for the rational design of novel pharmacotherapeutic approaches to suppress the excessive proliferation of mesangial cells in glomerular disease and hypertrophic tubular disease.