Insulin and multiplication-stimulating activity induce a very rapid centrosomal orientation response to wounding in...

Using serum-deprived monolayers of bovine aortic endothelial cells that were disrupted experimentally with a linear wound, we observed, by immunofluorescence microscopy, centrosomal perinuclear movement that is associated closely with cell orientation and locomotion. In the presence of the growth factors fetal bovine serum, insulin, or multiplication-stimulating activity (MSA), the centrosome rapidly (within 10 s) translocated and positioned itself between the nucleus and wound track in greater than or equal to 70% of cells bordering the wound. Random centrosomal orientation was observed in control border cells (50%). This growth factor-stimulated centrosomal orientation response to wounding depended on growth factor concentration, high-energy phosphates, functional microtubules and microfilaments, and calcium-calmodulin interaction. In the absence of fetal bovine serum, insulin, or MSA, the border cells of the wounded endothelial cell monolayer exhibited a significant centrosomal orientation response 5-6 h after wounding.