Fig. 5.

Mechanical strain increases TSP-1 expression. Astrocytes grown on deformable SILASTIC membranes were subjected to a rapid and reversible stretch (50-ms, 7.5-mm membrane displacement), and at various times later, TSP-1 expression was analyzed by immunoblotting (A and B) or immunocytochemistry (C–F). (A) Immunoblotting shows a time-dependent increase in TSP-1 expression after injury. β-Actin is a loading control. (B) Quantitation of data shows TSP-1 expression significantly increased 6 and 12 h (∗∗∗, P < 0.001; n = 3) after injury and returned to noninjured levels by 24 h. (C–F) Immunocytochemical experiments of uninjured cells or 6 h after injury show that mechanical strain increased TSP-1 expression (F) when compared with uninjured controls (D). In addition, after mechanical strain cells were more stellate and had longer processes and more intense GFAP immunoreactivity (E) than uninjured controls (C). Corresponding images in Left and Right are from the same fields. Red, TSP-1; green, GFAP; blue, DAPI. (Scale bars: 10 μm.)