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Multicenter trial of hemodilution in ischemic stroke--background and study protocol. Scandinavian Stroke Study Group.

Elin Åberg et al.Sep 1, 1985

Internal Medicine

Mechanical Engineering

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Novel Antibodies Reveal Inclusions Containing Non-Native SOD1 in Sporadic ALS Patients

Karin Forsberg et al.Jul 14, 2010

Mutations in CuZn-superoxide dismutase (SOD1) cause amyotrophic lateral sclerosis (ALS) and are found in 6% of ALS patients. Non-native and aggregation-prone forms of mutant SOD1s are thought to trigger the disease. Two sets of novel antibodies, raised in rabbits and chicken, against peptides spaced along the human SOD1 sequence, were by enzyme-linked immunosorbent assay and an immunocapture method shown to be specific for denatured SOD1. These were used to examine SOD1 in spinal cords of ALS patients lacking mutations in the enzyme. Small granular SOD1-immunoreactive inclusions were found in spinal motoneurons of all 37 sporadic and familial ALS patients studied, but only sparsely in 3 of 28 neurodegenerative and 2 of 19 non-neurological control patients. The granular inclusions were by confocal microscopy found to partly colocalize with markers for lysosomes but not with inclusions containing TAR DNA binding protein-43, ubiquitin or markers for endoplasmic reticulum, autophagosomes or mitochondria. Granular inclusions were also found in carriers of SOD1 mutations and in spinobulbar muscular atrophy (SBMA) patients and they were the major type of inclusion detected in ALS patients homozygous for the wild type-like D90A mutation. The findings suggest that SOD1 may be involved in ALS pathogenesis in patients lacking mutations in the enzyme.

Genetics

Molecular Biology

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SOD1 Enzymatic Activity in CSF from ALS patients with and without SOD1 mutations

Laura Leykam et al.Jun 16, 2024

Superoxide dismutase-1 (SOD1) mutations are a common cause of amyotrophic lateral sclerosis (ALS). Intrathecal gene therapy using the antisense-oligo-nucleotide drug tofersen to reduce SOD1 expression shows significant effects on disease progression and has recently been approved in the United States and the European Union. However, the discovery of children homozygous for four different inactivating SOD1 mutations developing the Infantile SOD1 Deficiency Syndrome (ISODDES) with injury to both upper and lower motor systems suggests that low SOD1 activities may be deleterious in humans. Monitoring SOD1 activity in cerebrospinal fluid (CSF) from tofersen-treated patients is advisable but difficult due to low levels and the presence of the isoenzyme SOD3. We here present a method to efficiently remove SOD3 from CSF using highly specific immobilized antibodies and subsequent measurement of the SOD activity as a sensitive assay for the SOD1 activity in CSF. We applied the method on CSF samples from ALS patients and controls and used paired erythrocyte samples for comparison. In ALS patients with wildtype SOD1, the SOD1 activity in CSF was the same as in controls, but patients with mutant SOD1 show lower activity in CSF, even patients with mutants previously reported to have full activity in erythrocytes. Activity variation is large among patients carrying the same SOD1 mutation and larger than seen in erythrocytes and in post-mortem central nervous system tissue. SOD1 in CSF shows a high specific activity, indicating that it is mainly native. Lastly, we identified a discrepancy between the SOD1 activity and protein level measured with ELISA in both CSF and erythrocytes. Since antibodies for SOD1 ELISA-quantification are raised against the native wildtype enzyme, the content of mutant SOD1s may be underestimated. Direct analysis of SOD1 enzymatic activity in CSF is therefore a more reliable way to monitor the effect of SOD1-lowering compounds.

Genetics

Biochemistry

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Genetics

Biochemistry

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