Figure 6.

Molecular signaling activated in reactive astrocytes induced by cell-autonomous ErbB activation. (a) Various intracellular signaling proteins were activated in the cerebral cortices of Mlc1-ErbB2^V664E mice, as increases of their phosphorylation levels were indicated by WB results. (b) Quantitative analyses of the protein phosphorylation levels revealed by WB. Phosphorylation levels of indicated proteins were normalized by its total protein levels. ***P<0.001; **P<0.01; *P<0.05; n=3 for each protein, paired t-test. (c) Specific elevation of both total protein levels and activity of STAT3 in the reactive astrocytes of Mlc1-ErbB2^V664E mice. Cortical slices of Mlc1-ErbB2^V664E and littermate control mice were co-immunostained for STAT3 or phosphorylated STAT3 (pSTAT3) together with GFAP. White arrows, representative double positive cells. (d) Specific activation of FAK and Src in the reactive astrocytes of Mlc1-ErbB2^V664E mice. Cortical slices of Mlc1-ErbB2^V664E and littermate control mice were co-immunostained by mouse antibody against GFAP and rabbit/goat antibodies against the active forms of FAK or Src, respectively. White arrows, representative double positive cells. Note that one of the active form of FAK (pY397) exhibited similar subcellular distribution pattern to the active form of Src (pY418).