Fig. 5: Elevated spine stiffness is observed prior to scoliosis onset, positively correlates with curve severity, and is fully suppressed by antioxidant therapy.

a, b Lateral wholemount images of wildtype and scoliotic sspo^dmh4/+ mutant zebrafish at 16 dpf (a, SL = 7.1 +/− 0.2 mm) and 21 dpf (b, SL = 8.9 +/− 0.6 mm). Scale bar = 2 mm. c, d Quantification of shear wave velocity measured by SWE along the spine of 16 dpf (c) and 21 dpf (d) zebrafish, demonstrating significantly greater shear wave velocity and thus spinal stiffness in sspo^dmh4/+ mutant animals. c N = 15 fish for each genotype. d N = 15 fish for each genotype. e Positive correlation between scoliosis severity (most severe Cobb-angle in sagittal or coronal plane) and spinal stiffness (shear wave velocity) in 21 dpf sspo^dmh4/+ zebrafish, post-curve onset (N = 20). Data was analyzed by a simple linear regression (R = 0.835, R² = 0.697, p < 0.0001). f Quantification of shear wave velocity measured by SWE along the spine of 10 dpf (SL = 4.7 +/− 0.4 mm) demonstrates significant elevation of spine stiffness in sspo^dmh4/+ mutant zebrafish, prior to scoliosis (N = 15 for each genotype and treatment). Antioxidant treatment (500 μM NACET) fully suppressed spine stiffness in sspo^dmh4/+ mutant zebrafish to wildtype levels. Violin plots show all data points, median (solid line), and quartiles (dotted line). Data were analyzed by a two-sided Mann–Whitney test (c, d) or a Kruskal–Wallis test followed by a Dunn’s multiple comparison test (f). (ns: non-significant (p > 0.05), **p ≤ 0.01, ***p ≤ 0.001, ****p ≤ 0.0001). Source data are provided as a Source Data file.