Fig. 1: Activation of signaling pathways by hIL-6 or PTEN^−/−.

a Schematic drawing illustrating the location of the AAV-injection sites (dashed box) shown in (b). b Coronal section of the sensorimotor cortex from a wild-type mouse 3 weeks after intracortical injection of AAV2-hIL-6 into the left hemisphere. The section was immunohistochemically stained for phosphorylated STAT3 (pSTAT3, red) and neuN (blue). GFP (green) was co-expressed by the AAV2-hIL-6. Scale bar: 500 µm. c Higher magnification of dotted box shown in (b). Scale bar: 200 µm. d–g Higher magnification of dotted boxes in (c). Scale bar: 50 µm. h–j Immunohistochemical staining against phosphorylated ribosomal protein S6 (pS6, red) of sections as described in (a). Dashed boxes are presented at higher magnification in (i, j). Scale bars: 50 µm (i, j); 500 µm (h). k Schematic drawing illustrating the injection site and location of images shown in (l, m). l, m Cortical sections of PTEN^f/f mice 3 weeks after AAV2-Cre-GFP (Cre-gfp), or AAV2-GFP (gfp) injections, stained for pS6 (l, red), or pSTAT3 (m, red). Scale bar: 50 µm. n Western blot analysis: lysates prepared from the sensorimotor cortex of PTEN^f/f mice 1, 3, 5, or 8 weeks (w) after intracortical injection of either AAV2-hIL-6 (hIL-6), AAV2-GFP (gfp) or 5 weeks after AAV2-Cre application leading to PTEN^−/−. AAV2-hIL-6 induced STAT3 phosphorylation (pSTAT3) at all tested time points, while PTEN^−/− only caused AKT phosphorylation. Total STAT3 protein remained mostly unaltered. Beta-actin served as a loading control. o–q Densitometric quantifications of western blots depicted in (n). Values represent means ± SEM of samples from 6 to 10 animals per group (gfp 1w, n = 6; hil-6 1w, n = 8; gfp 3w, n = 10; hIL-6 3w n = 10; gfp 5w, n = 7; hIL-6 5w, n = 8; gfp 8w, n = 6; hIL-6 8w, n = 6; PTEN^−/−, n = 6). r Western blot analysis of cortical lysates: Phosphorylation of ERK1/2 (pERK) was not altered by AAV2-GFP-, AAV2-hIL-6, or AAV2-Cre (PTEN^−/−) 5 weeks after intracortical application. Only PTEN^−/− induced significant S6-phosphorylation (pS6). s/t Densitometric quantification of western blots depicted in (r). Values represent means ± SEM of 6 independent cortical lysates (n = 6) per group. Representative immunohistochemical stainings shown in (b–j, l, m) were repeated four times with individual biological samples with similar results. Significances of intergroup differences in (o–q, s, t) were evaluated using a one-way analysis of variance (ANOVA) followed by Tukey post hoc test. Statistical significance is indicated by p-values. ns = non-significant. Dots in o-q, s, t represent values of single samples. Source data are provided as a Source data file.