Loss of STAT3 results in defective focal adhesion disassembly. (A and B) Longer LPA-induced FAs and their defective elongation on Src inhibition suggest that FA disassembly is defective in STAT3-CKO astrocytes (n = 239 and 169 FAs in WT, respectively, n = 273 and 202 FAs in STAT3-CKO, respectively; Kruskal-Wallis test, followed by Dunn’s test). Bars, 10 µm. (C) Colocalization of p-Src with paxillin and F-actin indicates that p-Src is concentrated in mature FA. Bars, 10 µm. (D) In contrast to WT astrocytes, the inhibition of Src kinases has no effect on the trans-well migration of STAT3-CKO astrocytes (ANOVA, two ways; and Bonferroni’s test). (E) Western blotting of astrocyte lysates with a specific antibody that detects Src (and other Src family members) only when dephosphorylated at tyrosine 416 indicates that the activation of Src family kinases is not reduced in STAT3-CKO astrocytes. The asterisk indicates the position of the band of Src kinases (∼60 kD), whereas the lower band is likely not specific. Ctrl, control. ns, not significant. Error bars indicate ±SEM. *, P < 0.05; ***, P < 0.001.