title: Effect of shear stress upon localization of the Golgi apparatus and microtubule organizing center in isolated cultured endothelial cells.
abstract: Despite substantial evidence to suggest that directed cell migration is dependent upon positioning of the Golgi apparatus (GA) and the microtubule organizing center (MTOC), some controversy exists about whether such a relationship is relevant to endothelial cells under flow. The present study was undertaken to provide an indepth investigation of the relationship between shear stress, GA/MTOC localization, cell migration and nuclear position. Bovine carotid endothelial cells were exposed to 22 or 88 dynes/cm2 for 0.5, 2, 8 or 24 h, and localization of their GA/MTOCs was determined relative to the direction of flow. In no-flow control specimens, (0, 0.5, 2, 8 and 24 h) there was no change in the equally distributed GA/MTOCs. In contrast, during the first 8 h at 88 dynes/cm2 and by 2 h at 22 dynes/cm2 there was a significant increase in the number of cells with GA/MTOCs localized upstream to flow direction. The effect was temporary, however, and by 24 h there was no significant difference between the no-flow, 22 and 88 dynes/cm2 specimens. Analysis of GA/MTOC localization with respect to the direction of cell migration determined that 72.5% of no-flow cells possessed GA/MTOCs localized to the sides of nuclei nearest the direction of migration. In contrast, 64% of the specimens shear stressed over the same time period had GA/MTOCs localized to the sides of nuclei opposite the direction of migration. These results suggest that positioning of the GA/MTOC in endothelial cells is not dependent completely upon the direction of migration.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Hope Heart Research Institute, Seattle, Washington 98122.
authors.forename: D E
authors.initials: DE
authors.lastname: Coan
authors.forename: A R
authors.initials: AR
authors.lastname: Wechezak
authors.forename: R F
authors.initials: RF
authors.lastname: Viggers
authors.forename: L R
authors.initials: LR
authors.lastname: Sauvage
mesh_terms: D000818:Animals; D002417:Cattle; D002465:Cell Movement / Q000502:physiology; D002467:Cell Nucleus / Q000648:ultrastructure*; D002469:Cell Separation; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000648:ultrastructure*; D006056:Golgi Apparatus / Q000648:ultrastructure*; D008870:Microtubules / Q000648:ultrastructure*; D013314:Stress, Mechanical