Influence of MSC CM on astrocytes under STS treatment.

<p>Astrocyte cultures were examined at high magnification by fluorescence microscopy after GFAP staining. Cultures were incubated for 48 h in conditioned medium, 1 µM STS was added during the last 24 h. A: MTT assay showed significantly increased survival of non-transgenic astrocytes in presence of 20% and 30% CM. B: Immunocytochemical quantification of astrocyte survival showed most efficient attenuation of STS-induced apoptosis with a 30% dilution of CM, whereas concentrations higher than 50% CM did not mediate significant protective effects. STS-sensitivity of non-transgenic and SOD1G93A transgenic astrocytes did not significantly differ. Values represent means ± SEM, ***<i>p</i><0.001, **<i>p</i><0.01, *<i>p</i><0.05, two-way ANOVA with Bonferroni post-test (Fig. 4B); one-way ANOVA with Bonferroni post-test (Fig. 4A). C: Immunostainings revealed STS-induced apoptosis of astrocytes (a as compared to b) and a protective effect of MSC CM (c).