Experiments With Osteoblasts Cultured Under Hypergravity Conditions
Creator
Kacena M A; Todd P; Gerstenfeld L C; Landis W J
Publisher
Microgravity Science and Technology
Date
2004
2004
Description
To understand further the role of gravity in osteoblast attachment, osteoblasts were subjected to hypergravity conditions in vitro. Scanning electron microscopy of all confluent coverslips from FPA units show that the number of attached osteoblasts was similar among gravitational levels and growth durations (similar to90 cells/microscopic field). Specifically. confluent 1.0G control cultures contained an average of 91+/-8 cells/field, 3.3G samples had 88+/-8 cells/field, and 4.0G cultures averaged 90+/-7 cells/field. The sparsely plated cultures assessed by immunohistochemistry also had similar numbers of cells at each time point (1.0G was similar to 3.3 and 4.0G), but cell number changed from one time point to the next as those cells proliferated Immunohistochemistry of centrifuged samples showed an increase in number (up to 160% increase) and thickness (tip to 49% increase) of actin fibers, a decrease in intensity of fibro-nectin fluorescence (18-23% decrease) and an increase in number of vinculin bulbs (202-374% increase in number of vinculin bulbs/area). While hypergravity exposure did not alter the number of attached osteoblasts, it did result in altered actin, fibronectin, and vinculin elements, changing some aspects of osteoblast-substrate adhesion.