Figure 2.
Dynamic Remodeling of Astrocyte Mitochondrial and ER Networks following Injury
(A) Experimental design.
(B) Example of an hGFAP::CreER x R26LSL-mitoYFP mouse at 7 days after cortical SW injury. Inset: extravasating CD45+ leukocytes in the lesion core. Scale bar, 150 μm.
(C) Surface rendering of mitoYFP+ control (uninjured animals) or reactive astrocytes proximal to the lesion track. Arrowheads point to the soma. Zooms depict the network morphology in branches. Scale bar, 15 μm.
(D) Density plots depicting the mitochondrial heterogeneity in resting (Ctrl, uninjured animals) or reactive astrocytes (SW 7 days). Threshold values for mitochondrial sphericity (0.8) and length (1 μm) are shown.
(E) Time course of mitochondrial fragmentation quantified as in (D) (n ≥ 3 mice/time point, 8–15 astrocytes/mouse; one-way ANOVA followed by Dunnett’s post hoc test).
(F) Volume reconstruction of mitoYFP+ reactive astrocytes (arrowheads) surrounding dextran-labeled vessels. Scale bar, 25 μm.
(G) Vessel cross-sections showing astrocytic mitoYFP in control (uninjured animals) and injured conditions. Scale bar, 10 μm.
(H) Quantification of perivascular mitoYFP (n ≥ 30 vessels/time point; nonparametric Kruskal-Wallis test).
(I) Experimental design for analyzing the astrocytic ER.
(J) 3D example of an astrocyte expressing ER-GFP (signal density shown in pseudocolors). Scale bars, 10 and 5 μm.
(K) Quantification of the ER-GFP perivascular g-ratio at the indicated time points (n ≥ 35 vessels/time point; nonparametric Kruskal-Wallis test). ∗∗p < 0.01, ∗∗∗p < 0.001.
See also Figure S2.