Fig. 4
From: Stathmin 1/2-triggered microtubule loss mediates Golgi fragmentation in mutant SOD1 motor neurons
Early and rapidly progressive co-accumulation of Stathmin 1, Stathmin 2 and GS28 in motor neurons of mutant SOD1 mice. a. Western blots show expression of Stathmin 1, Stathmin 2 and GS28 in lumbar spinal cords of SOD1G85R mice (upper panels), SOD1G93A mice (lower panels) and corresponding litter mates. Analyses were performed at ages P8, P30, P180 and P240. Loading control β-actin. Each blot was performed in duplicate and is representative of four animals per genotype. b. Diagrams showing kinetics of Stathmin 1, Stathmin 2 and GS28 protein levels in lumbar spinal cords of mutant SOD1G85R mice and SOD1G93A mice. Stathmin 1 and 2 levels are already significantly increased at P8. Fold changes (mean ± sd) are determined from four spinal cords per genotype and time point and expressed relative to the levels in non-transgenic littermate controls (set to 1). Differences between mutant SOD1 and control are statistically significant as measured by Mann Whitney test (*, p < 0.01). c-d. Confocal images of lumbar spinal cord cross sections from non-transgenic, SOD1G85R and SOD1G93A mice aged 240 days showing accumulation of Stathmin 1 (C, upper panels), Stathmin 2 (D, upper panels) and GS28 (C-D, lower panels) in motor neurons, which sometimes appear as degenerating. Note motor neurons with either low expression (arrowheads) or high expression (arrows) of Stathmins and Golgi SNAREs. Scale bar 20 μm. e. Diagram showing immunoreactivities (IR) of Stathmin 1 (x-axis) and GS28 (y-axis) in motor neurons of control non-transgenic mice (in blue) and mutant SOD1G85R mice (in red). Pearson analysis demonstrates significant correlation between both parameters: r = 0.28, p < 0.0066 (ctrl) and r = 0.47, p < 0.0001 (SOD1G85R). The slopes of the regression curves are 0.49 ± 0.18 (ctrl) and 0.68 ± 0.13 (SOD1G85R), n = 91 cells (ctrl) and n = 99 cells (SOD1G85R) analyzed from n = 3 mice per genotype. f. Immunoreactivities of Stathmin 2 and GS28 also show significant correlation by Pearson analysis: r = 0.40, p < 0.0047 (ctrl), r = 0.69, p < 0.0001 (SOD1G85R). The slopes of the regression curves are 0.29 ± 0.09 (ctrl) and 0.60 ± 0.09 (SOD1G85R) by linear regression analysis, n = 47 cells and n = 48 cells analyzed respectively from n = 3 mice per genotype