Senda Ajroud-Driss

FUS-immunoreactive inclusions are a common feature in sporadic and non-SOD1 familial amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal disorder of motor neuron degeneration. Most cases of ALS are sporadic (SALS), but about 5 to 10% of ALS cases are familial (FALS). Recent studies have shown that mutations in FUS are causal in approximately 4 to 5% of FALS and some apparent SALS cases. The pathogenic mechanism of the mutant FUS‐mediated ALS and potential roles of FUS in non‐FUS ALS remain to be investigated.

Sporadic and hereditary amyotrophic lateral sclerosis (ALS)

Genetic discoveries in ALS have a significant impact on deciphering molecular mechanisms of motor neuron degeneration. The identification of SOD1 as the first genetic cause of ALS led to the engineering of the SOD1 mouse, the backbone of ALS research, and set the stage for future genetic breakthroughs. In addition, careful analysis of ALS pathology added valuable pieces to the ALS puzzle. From this joint effort, major pathogenic pathways emerged. Whereas the study of TDP43, FUS and C9ORF72 pointed to the possible involvement of RNA biology in motor neuron survival, recent work on P62 and UBQLN2 refocused research on protein degradation pathways. Despite all these efforts, the etiology of most cases of sporadic ALS remains elusive. Newly acquired genomic tools now allow the identification of genetic and epigenetic factors that can either increase ALS risk or modulate disease phenotype. These developments will certainly allow for better disease modeling to identify novel therapeutic targets for ALS. This article is part of a Special Issue entitled: Neuromuscular Diseases: Pathology and Molecular Pathogenesis.

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.

Gastrostomy tube placement by endoscopy versus radiologic methods in patients with ALS: A retrospective study of complications and outcome

Abstract Gastrostomy tube placement for malnutrition and weight loss stabilization occurs in many patients with ALS. We sought to compare the outcome and complications of gastrostomy tube placement by endoscopic (PEG) and multiple radiologic (RIG) methods in ALS patients. A retrospective analysis was conducted on all ALS patients evaluated at Northwestern University who received gastrostomy tubes between January 2009 and March 2012. One hundred and eight gastrostomy tube attempts were made on a total of 100 different patients. Failed gastrostomy tube placement occurred in 15.7% of PEGs and 1.9% of RIGs. Post-procedure aspiration was recognized after 10.5% PEG and 0 RIG attempts. Multivariate analysis revealed a linear increase in risk of post-procedure aspiration for every increase in ALSFRS swallow score. No statistically significant differences in failure or complications were observed when comparing two different methods of RIG (push-type vs. pull-type). Our findings support gastrostomy tube placement by radiographic methods in ALS patients. Gastrostomy tube placement by RIG was more often successful and less often associated with aspiration. Our findings add to the growing body of literature that argues for early gastrostomy tube placement in young patients with prominent bulbar involvement.

Prevalence and characteristics of pain in early and late stages of ALS.

Abstract The purpose of this study was to compare pain frequency in early and late stages of ALS and to describe the relationship between pain intensity and functional status. Sixty-four patients in different stages of ALS were asked to complete the Neuropathic Pain Scale and to draw the localization of their pain on a body cartoon. The Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) and Forced Vital Capacity (FVC) values were obtained from the medical record. A χ2 correlation was used to compare the proportion of patients with pain in different stages of ALS. Correlation coefficient was used to describe the relationship between pain intensity and functional status (ALSFRS-R). Pain was reported by about half the patients. Using FVC values, patients were subdivided into early, intermediate and late stage of the disease. There was a negative correlation between pain intensity and functional status. There was no statistically significant difference in the presence of pain among patients in the different stages of ALS. In conclusion, our study showed that pain is common in ALS patients. Although pain intensity did correlate negatively with functional status, as expected, we were surprised to find that pain was also present in the early stages of the disease.

Phase 1/2 Open-label Dose-escalation Study of Plasmid DNA Expressing Two Isoforms of Hepatocyte Growth Factor in Patients With Painful Diabetic Peripheral Neuropathy

This study aimed to evaluate the safety and preliminary efficacy of intramuscular injections of plasmid DNA (VM202) expressing two isoforms of hepatocyte growth factor (HGF) in subjects with painful diabetic peripheral neuropathy (PDPN). Twelve patients in three cohorts (4, 8, and 16 mg) received two sets of VM202 injections separated by two weeks. Safety and tolerability were evaluated and the visual analog scale (VAS), the short form McGill questionnaire (SF-MPQ), and the brief pain inventory for patients with diabetic peripheral neuropathy (BPI-DPN) measured pain level throughout 12 months after treatment. No serious adverse events (AEs) were observed. The mean VAS was reduced from baseline by 47.2% (P = 0.002) at 6 months and by 44.1% (P = 0.005) at 12 months after treatment. The VAS scores for the 4, 8, and 16 mg dose cohorts at 6 months follow-up decreased in a dose-responsive manner, by 21% (P = 0.971), 53% (P = 0.014), and 62% (P = 0.001), respectively. The results with the BPI-DPN and SF-MPQ showed patterns similar to the VAS scores. In conclusion, VM202 treatment appeared to be safe, well tolerated, and sufficient to provide long term symptomatic relief and improvement in the quality of life in patients with PDPN.

Molecular mechanisms and animal models of spinal muscular atrophy

Spinal muscular atrophy (SMA), the leading genetic cause of infant mortality, is characterized by the degeneration of spinal motor neurons and muscle atrophy. Although the genetic cause of SMA has been mapped to the Survival Motor Neuron1 (SMN1) gene, mechanisms underlying selective motor neuron degeneration in SMA remain largely unknown. Here we review the latest developments and our current understanding of the molecular mechanisms underlying SMA pathogenesis, focusing on the animal model systems that have been developed, as well as new diagnostic and treatment strategies that have been identified using these model systems. This article is part of a special issue entitled: Neuromuscular Diseases: Pathology and Molecular Pathogenesis.

Gender difference in levels of Cu/Zn superoxide dismutase (SOD1) in cerebrospinal fluid of patients with amyotrophic lateral sclerosis.

Currently the best studied mechanism for amyotrophic lateral sclerosis (ALS) is the one caused by mutations in the gene for cytosolic Cu/Zn-binding superoxide dismutase (SOD1). Mutant SOD1 protein causes motor neuron degeneration due to the gain of a novel toxic function. To evaluate the relevance of SOD1 levels in cerebrospinal fluid (CSF) in ALS patients, the SOD1 concentration was immunoassayed in the CSF of 11 patients with ALS and 19 neurological controls. The mean level of SOD1 in CSF from all samples was 45.5+/−11.3 ng/ml. There was no statistically significant difference between the levels of SOD1 in CSF of ALS patients and neurological control subjects. Here we show that the SOD1 concentration in the CSF is significantly higher in male ALS patients (54.0+/−9.0 ng/ml) compared to female ALS patients (38.1+/−6.4 ng/ml) (p=0.007). This gender difference is not observed in the CSF of neurological controls. This is the first report of a potential gender difference in levels of SOD1 in CSF of ALS patients. Further investigation of larger sample groups is needed to determine whether it is relevant to gender related differences in disease incidence.

Double-blind, placebo-controlled study of HGF gene therapy in diabetic neuropathy.

To evaluate the safety and efficacy of a plasmid (VM202) containing two human hepatocyte growth factor isoforms given by intramuscular injections in patients with painful diabetic neuropathy.

Riluzole metabolism and CYP1A1/2 polymorphisms in patients with ALS

Riluzole is the only FDA approved drug for the treatment of amyotrophic lateral sclerosis. Riluzole is assumed to be mainly metabolized by the liver cytochrome CYP1A2 and by the extra‐hepatic cytochrome CYP1A1. CYP1A2 and CYP1A1 genetic polymorphisms are known, but their relationship to riluzole metabolism in ALS patients has not been investigated. The aim of this study was to determine whether the polymorphisms of the CYP1A2 and the CYP1A1 genes in ALS patients are associated with riluzole metabolic profiles. Thirty‐two patients with a diagnosis of probable or definite ALS and who were on riluzole, participated in the study. Trough and peak plasma riluzole levels were measured using analytical chromatography‐mass spectrometry methods. Association of the genotypes of the SNPs spanning the CYP1A1 and CYP1A2 genes (including one SNP in the intergenic region) with mean riluzole peak and trough levels was studied using ANOVA and Tukeys HSD. The mean peak riluzole level was 202±111 ng/ml and mean trough level 54.3±37.5 ng/ml. Our data do not support any association of the four CYP1A1 and CYP1A2 polymorphisms with the riluzole metabolic profile. In conclusion, genetic variations in CYP1A1 and CYP1A2 genes do not seem to influence riluzole levels. Further work is needed to better understand the genetic regulation of CYP1A enzymes and their role in riluzole metabolism.