Insulin-like Growth Factor I (IGF-I) Induces Unique Effects in the Cytoskeleton of Cultured Rat Glomerular Mesangial CellsAnne K. Berfielda, Douglas Spicera, and Christine K. Abrassaa Division of Nephrology and Department of Medicine, Veterans Affairs Medical Center and the University of Washington School of Medicine, Seattle, Washington Correspondence to: Christine K. Abrass, (111A), Veterans Affairs Medical Center, 1660 S. Columbian Way, Seattle, WA 98108.
Resident glomerular mesangial cells (MCs) have complex cytoskeletal organizations that maintain functional and structural integrity. The ability of cells to replicate, coordinate movement, change shape, and interact with contiguous cells or extracellular matrix depends on cytoskeletal organization. MCs synthesize insulin-like growth factor (IGF-I), express IGF-I receptors, and respond to IGF-I with increased proliferation. We noted that IGF-I treatment of mesangial cells was associated with a change in morphology. Therefore, these studies were undertaken to define specific IGF-I-mediated changes in cytoskeletal protein organization. Rat MCs were propagated from birth in culture without supplemental insulin. Quiescent, subconfluent cultures were treated with IGF-I (100 nM) for 1 hr. Rearrangements in f-actin, Key Words: IGF-I, cytoskeleton, glomerulus, mesangial cell, cell shape, migration
|
|
||||||||||||||