Both profilins have a drastic effect on spreading of astrocytes.

<p>(A) Spreading assay. Astrocytes were allowed to adhere to PLO-coated coverslips for 6 hours, were subsequently fixed and stained with (A) phalloidin as well as (A’) anti-GFAP to identify astrocytes and DAPI to stain for nuclei (A”). According to their morphology and the appearance of their actin cytoskeleton, cells were classified into two groups: round cells lacking obvious spreading (group 1) and well spread cells (group 2). Scale bar: 5 μm (B) Statistical analysis of astrocytes transduced with either Usifluc (MOCK, black), Ush1.3 (PFN1 KD, white) or Ush2.13 (PFN2a KD, light grey) subjected to the spreading assay in A and subsequently classified into groups 1 and 2. 60.6±1.9% of control cells were classified into group 2, whereas only 38.6±1.5% of PFN1 knockdown cells and 43.0±2.1% of PFN2a knockdown cells were well-spread according to criteria. Quantitative data obtained from 3 independent experiments was tested for significance by one-way ANOVA followed by a <i>post-hoc</i> Tukey’s Multiple Comparison Test. Significance is indicated as follows *p<0.05; **p<0.01; ***p<0.001. Data are shown as mean ± SEM.