Extended Data Fig. 6. Mechanical reinforcement of Lmna KO myonuclei by microtubule stabilization reduces nuclear damage.

(a) Representative image of nuclear deformation following microharpoon strain application in Lmna KO myotubes at day five of differentiation. Myotubes were treated for 24 hours with either paclitaxel or DMSO control. Yellow dotted line denotes the perimeter of the nucleus prior to strain application. Scale bar: 20μm. Similar results were obtained in >10 nuclei in at least three independent experiments (see panel b). (b) Quantification of nuclear strain in Lmna WT and Lmna KO myofibers using microharpoon assay following 24 hours of treatment with 50 nM paclitaxel or DMSO vehicle control. Data points are from n nuclei per genotype and condition from three independent experiments. Significance determined by two-way ANOVA (genotype; drug treatment), using Tukey’s correction for multiple comparisons. (c) Quantification of chromatin protrusions at day 7 of differentiation, following treatment with paclitaxel (50 nM) or DMSO starting at day 4 of differentiation. Data based on n independent experiments per condition. Significance determined by one-way ANOVA, using Tukey’s correction for multiple comparisons. (d) Quantification of cGAS-mCherry foci formation during 10 myofiber differentiation following treatment with paclitaxel (10 nM) or DMSO control, starting at day 5 of differentiation. Data based on n = 3 independent experiments. All bar plots show mean value ± standard error of the mean.