Fig. 2: hUC-MSCs improves motor dysfunction in a systemic mouse model of NMO.

a Schematic diagram and experimental procedures for assessing motor performance in NMO mouse models with hUC-MSCs treatment. (1) Subcutaneous injections of 50 μL of complete Freund’s adjuvant (CFA) containing 50 μg heat-killed H37Ra mycobacterium tuberculosis per site and 200 ng of pertussis toxin (PTX) were administered intraperitoneally (i.p.) twice to disrupt the blood–brain barrier (BBB) before IgG transfer. (2) From day 0 to 10, mice received daily I.P. injections of hsAQP4-IgG or hsCtrl-IgG. Each mouse received 4 mg of human IgG per day for 10 days (green row). (3) The NMO mouse models received hUC-MSCs treatment. Four groups of hUC-MSCs treatment were administered: after 2 days of IgG injection, the mice were treated with hUC-MSCs at the following doses: 4 × 10⁵ cells per mouse, one time tail vein injection (1x Low group); 1 × 10⁶ cells per mouse, one time tail vein injection (1x High group); 4 × 10⁵ cells per mouse, two times tail vein injection on the day 2 and day 6 (2x Low group); and 1 × 10⁶ cells per mouse, two times tail vein injection (2x High group). The standardized behavioral tests of the rotarod and gait test were performed on days 0, 2, 4, 6, 8, and 10. b Representative images and quantification of stride length on days 0 and 10. The data show that mice administered hsAQP4-IgG presented with reduced stride length on day 10, and hUC-MSCs treatment ameliorated the motor impairments. n = 6 animals per group. c Schematic diagram and quantification of the rotarod test. The data show that the hsAQP4-IgG-treated mice had an increased tendency to fall compared with hsCtrl-IgG-treated mice. hUC-MSCs treatment improved the motor impairment by extending the average latency time interval at which mice fell off. n = 6 animals per group. d Schematic diagram showing the cross-section of L4 spinal cord that were used for immunostaining, western blot, and ELISA analysis. e Representative confocal images and quantification of NeuN⁺ ventral horn motor neurons of the indicated groups. The data show that hUC-MSCs treatment ameliorated NeuN⁺ positive cells induced by hsAQP4-IgG. n = 5 animals per group. Scale bar, 100 µm. f Bar graph of the 11 overlapped NF-κB-targeted gene expression levels in L4 spinal cord lysates by ELISA analysis of the indicated groups. n = 3 animals per group. All data in the bar graphs of b, c, e, and f were presented as the mean ± SEM; the statistical evaluation of (c) was analyzed with two-way ANOVA with Tukey’s multiple comparisons test; for b, e, and f, the statistical significance was evaluated with one-way ANOVA and Tukey’s post hoc multiple comparisons. Non-significant comparisons are not identified. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. CFA complete Freund’s adjuvant, PTX pertussis toxin.