Interleukin-6 Deficiency Does Not Affect Motor Neuron Disease Caused by Superoxide Dismutase 1 Mutation
Fig 2
Relative changes in body weight, clinical score and survival in ALS mice.
(A-F) Hind limb extension of WT mouse, IL-6(-/-) mouse (160–180 days of age), SOD1 TG/IL-6(+/+) mice and SOD1 TG/IL-6(-/-) mice (the early stage and the end stage), when suspended by their tail. (G) Kaplan-Meier time–to-failure plot for onset of symptomatic neurological disease in ALS mice. Neurological symptoms of SOD1 TG/IL-6(-/-) (n = 17), SOD1 TG/IL-6(+/-) (n = 18) and SOD1 TG/IL-6(+/+) (n = 11) were monitored. The age at which mice attain a neurological severity score 2 is taken to be definitive onset of symptomatic neurological disease (p = 0.597 by log rank test for onset of symptomatic neurological disease). (H) The clinical score of SOD1 TG/IL-6(-/-) mice in comparison with those of SOD1 TG/IL-6(+/-) mice and SOD1 TG/IL-6(+/+) mice. Score criteria (severity from 0 to 4) are shown in materials and methods. SOD1 TG/IL-6 (-/-) (n = 17), SOD1 TG/IL-6(+/-) (n = 18), SOD1 TG /IL-6(+/+) (n = 11), IL-6(-/-) (n = 8), WT (n = 15), IL-6(+/-) (n = 5). WT, IL-6(-/-) or IL-6(+/-) mice showed no disease symptoms. (I) Relative changes in body weight of SOD1 TG/IL-6(-/-) mice (n = 17), SOD1 TG /IL-6(+/-) mice (n = 18) and SOD1 TG /IL-6(+/+) mice (n = 11). Peak body weight of each mouse was calculated as 1. (J) Kaplan-Meier time–to-failure plot for onset of body weight loss of SOD1 TG/IL-6(-/-), SOD1 TG/IL-6(+/-) and SOD1 TG/IL-6(+/+) mice. The age at which mice attained a peak body weight was analyzed (p = 0.595 by log rank test). (K) Kaplan-Meier time–to-failure plot for survival of SOD1 TG/IL-6(-/-), SOD1 TG/IL-6(+/-) and SOD1 TG/IL-6(+/+) mice (p = 0.430 by log rank test). The survival of SOD1 TG/IL-6(-/-) (n = 17), SOD1 TG/IL-6(+/-) (n = 18) and SOD1 TG/IL-6(+/+) (n = 11) was monitored. The mean (± SD) life spans were; SOD1 TG/IL-6(-/-) 167.55 ± 11.52 days, SOD1 TG/IL-6(+/-) 161.82 ± 12.69 days, TG/IL-6(+/+) 164.31 ± 12.16 days.