Comparisons of Endothelial Cell G- and F-Actin Distribution in Situ and in Vitro
Abstract
Numerous studies have described the F-actin cytoskeleton; however, little information relevant to G-actin is available. The actin pools of bovine aortic endothelial cells were examined using in situ and in vitro conditions and fluorescent probes for G-(deoxyribonuclease I, 0.3 micrometers) or F-actin (phalloidin, 0.2 micrometers). Cells in situ displayed a diffuse G-actin distribution, while F-actin was concentrated in the cell periphery and in fine stress fibers that traversed some cells. Cells of subconfluent or just confluent cultures demonstrated intense fluorescence, with many F-actin stress fibers. Postconfluent cultures resembled the condition in situ; peripheral F-actin was prominent, traversing actin stress fibers were greatly reduced and fluorescent intensity was diminished. Postconfluency had little influence on G-actin, with only an enhancement in the intensity of G-actin punctate fluorescence. When post-confluent cultures were incubated with cytochalasin D (15 min; 10(-4) M), F-actin networks were disrupted and actin punctate and diffuse fluorescence increased. G-actin fluorescence was not altered by the incubation. Although its unstructured nature may account for the minor changes observed, the stability of the G-actin pool in the presence of notable F-actin modulations suggested that filamentous actin was the key constituent involved in these actin cytoskeletal alterations. A separate finding illustrated that the concomitant use of actin probes with image enhancement and fluorescent microscopy could reveal veal simultaneously the G- and F-actin pools within the same cell.... Endothelial cells, Actin, Phalloidin, DNase.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1993
- Accession Number
- ADA264312
Entities
People
- David A. Dubose
- Rosaria Haugland
Organizations
- United States Army Research Institute of Environmental Medicine