Differential Involvement of Optineurin in Amyotrophic Lateral Sclerosis With or Without SOD1 Mutations

Background Mutations in optineurin have recently been linked to amyotrophic lateral sclerosis (ALS). Objective To determine whether optineurin-positive skeinlike inclusions are a common pathologic feature in ALS, including SOD1 -linked ALS. Design Clinical case series. Setting Academic referral center. Subjects We analyzed spinal cord sections from 46 clinically and pathologically diagnosed ALS cases and ALS transgenic mouse models overexpressing ALS-linked SOD1 mutations G93A or L126Z. Results We observed optineurin-immunoreactive skeinlike inclusions in all the sporadic ALS and familial ALS cases without SOD1 mutation, but not in cases with SOD1 mutations or in transgenic mice overexpressing the ALS-linked SOD1 mutations G93A or L126Z. Conclusion The data from this study provide evidence that optineurin is involved in the pathogenesis of sporadic ALS and non- SOD1 familial ALS, thus supporting the hypothesis that these forms of ALS share a pathway that is distinct from that of SOD1 -linked ALS.