Oxidative stress profiles of lymphoblasts from Amyotrophic Lateral Sclerosis patients with or without known SOD1 Mutations

Abstract

Amyotrophic lateral sclerosis (ALS) is a fatal and rapidly progressing neurodegenerative disease that affects motor neurons. This disease is associated with oxidative stress especially in mutant superoxide dismutase 1 (mutSOD1) patients. However, less is known for the most prevalent sporadic ALS due to a lack of disease models. Here, we studied oxidative the stress profiles in lymphoblasts from ALS patients with mutSOD1 or unknown (undSOD1) mutations. mutSOD1 and undSOD1 lymphoblasts, as well as sex/age-matched controls (3/group) were obtained from Coriell and divided in 46 years-old-men (C1), 46 years-old-women (C2) or 26/27 years-old-men (C3) cohorts. Growth curves were performed, and several parameters associated with redox homeostasis were evaluated, including SOD activity and expression, general oxidative stress levels, lipid peroxidation, response to oxidative stimulus, glutathione redox cycle, catalase expression, and activity, and Nrf2 transcripts. Pooled (all cohorts) and paired (intra-cohort) statistical analyses were performed, followed by clustering and principal component analyses (PCA). Although a high heterogeneity among lymphoblast redox profiles was found between cohorts, clustering analysis based on 7 parameters with high chi-square ranking (total SOD activity, oxidative stress levels, catalase transcripts, SOD1 protein levels, metabolic response to mM concentrations of tert-butyl hydroperoxide, glutathione reductase activity, and Nrf2 transcript levels) provided a perfect separation between samples from healthy controls and ALS (undSOD1 and mutSOD1), also visualized in the PCA analysis. Our results show distinct redox signatures in lymphoblasts from mutSOD1, undSOD1, and healthy controls that can be used as therapeutic targets for ALS drug development. Highlights Lymphoblasts from ALS patients present altered redox properties Redox profiling evidenced total SOD and glutathione reductase activities, SOD1 protein levels, DCF fluorescence, catalase and Nrf2 transcripts, and tert-butyl hydroperoxide cytotoxicity, as discriminant features for experimental groups. Lymphoblast redox profiles may be helpful for patient stratification and precision medicine