Figure 2.

Dysferlinopathic myoblasts show poor cell membrane repair. (a) C2C12 cells injured in the presence of FITC-dextran (green) were allowed to undergo repair in TRITC-dextran (red) and then stained with Hoechst 33342 (blue). Uninjured cells are not labeled with dextran (upper left panel); injured cells are labeled green, and cells that failed to repair themselves are labeled red and green. Upper panels show uninjured myoblasts and myoblasts that failed to repair themselves because of a lack of Ca²⁺. Lower panel shows C2C12 and C2C12-shRNA myoblasts injured and allowed to repair themselves in the presence of Ca²⁺; Scale bar: 50 μm. (b) Images of glass bead-injured cells were quantified (>100 cells each) and are presented as the fraction of cells that failed to show repair in the presence of Ca²⁺. (c) FM1-43 influx following focal laser injury in >10 myoblasts injured in the presence of Ca²⁺ shows efficient repair from laser injury; cells injured in the absence of Ca²⁺ do not. (d) Quantification of FM1-43 influx by time-lapse imaging of >15 myoblasts each following injury in the presence of Ca²⁺, showing poor healing of C2C12-shRNA myoblasts. Data in b, c and d show means±S.E.M.; ***P<0.001 by unpaired Student's t-test