Local Overexpression of Interleukin-11 in the Central Nervous System Limits Demyelination and Enhances Remyelination
Figure 5
Therapeutic overexpression of IL-11 promotes endogenous remyelination. Representative images of electron micrographs (panel (a)) of midsagittal cross sections of the corpus callosum reveal significant demyelination after 4 weeks of cuprizone diet and remyelination after 5 weeks of cuprizone diet followed by 2 weeks of normal diet. Quantitative analysis shows that therapeutic overexpression of IL-11 (b) enhances remyelination as indicated by a decrease in G-ratio (c) without affecting the mean axonal diameter. (d) Quantitative and qualitative analysis reveals that 4 weeks of cuprizone treatment reduced the density of myelinated axons and again increased after the animals were allowed to remyelinate for two weeks. The values shown in the bars represent the percentage of axons of that category with respect to the total number of demyelinated and myelinated axons. Axons were categorized in different groups based on their individual G ratio: axons were defined as spared (G ratio < 0.74), remyelinating (0.74 < G ratio > 0.9), and demyelinated (G ratio > 0.90). Per mouse, quantification was performed in 5 randomly selected areas in the electron micrographs of midsagittal cross sections of the corpus callosum taken between anterioposterior coordinates from −0.3 to −1.5 mm in reference to bregma. Data is presented as mean ± SEM ( animals for each group). Statistical significance was analyzed by one-way ANOVA followed by Bonferroni’s multiple comparison test. , compared to healthy control group; * compared to 5 wk CUP 2 wk RM + PBS group; # compared to 5 wk CUP 2 wk RM + eGFP-LV group; @ compared to 4 wk DM group.
