The intestinal microbiota may be involved, through metabolic gut-brain interactions, in a variety of neurological conditions. In this addendum, we summarize the findings of our recent study ...investigating the potentially modulatory influence of the microbiome in a transgenic ALS mouse model, and the possible application to human disease. We found that transgenic mice show evidence of dysbiosis, even at the pre-symptomatic stage, and have a more severe disease course under germ-free conditions or after receiving broad-spectrum antibiotics. We demonstrated that Akkermansia muciniphila ameliorated the disease in mice and that this may be due to the production of nicotinamide. We then conducted a preliminary study in human ALS and identified functionally similar alterations within the metagenome. Furthermore, we found that patients with ALS had lower systemic and CSF levels of nicotinamide, suggesting that the changes observed in the mouse model may be relevant to human disease.
To discover novel genes underlying amyotrophic lateral sclerosis (ALS), we aggregated exomes from 3,864 cases and 7,839 ancestry-matched controls. We observed a significant excess of rare ...protein-truncating variants among ALS cases, and these variants were concentrated in constrained genes. Through gene level analyses, we replicated known ALS genes including SOD1, NEK1 and FUS. We also observed multiple distinct protein-truncating variants in a highly constrained gene, DNAJC7. The signal in DNAJC7 exceeded genome-wide significance, and immunoblotting assays showed depletion of DNAJC7 protein in fibroblasts in a patient with ALS carrying the p.Arg156Ter variant. DNAJC7 encodes a member of the heat-shock protein family, HSP40, which, along with HSP70 proteins, facilitates protein homeostasis, including folding of newly synthesized polypeptides and clearance of degraded proteins. When these processes are not regulated, misfolding and accumulation of aberrant proteins can occur and lead to protein aggregation, which is a pathological hallmark of neurodegeneration. Our results highlight DNAJC7 as a novel gene for ALS.
Malfunction of astrocytes is implicated as one of the pathological factors of ALS. Thus, intrathecal injection of healthy astrocytes in ALS can potentially compensate for the diseased astrocytes. ...AstroRx® is an allogeneic cell-based product, composed of healthy and functional human astrocytes derived from embryonic stem cells. AstroRx® was shown to clear excessive glutamate, reduce oxidative stress, secrete various neuroprotective factors, and act as an immunomodulator. Intrathecal injection of AstroRx® to animal models of ALS slowed disease progression and extended survival. Here we report the result of a first-in-human clinical study evaluating intrathecal injection of AstroRx® in ALS patients.
We conducted a phase I/IIa, open-label, dose-escalating clinical trial to evaluate the safety, tolerability, and therapeutic effects of intrathecal injection of AstroRx® in patients with ALS. Five patients were injected intrathecally with a single dose of 100 × 10
AstroRx® cells and 5 patients with 250 × 10
cells (low and high dose, respectively). Safety and efficacy assessments were recorded for 3 months pre-treatment (run-in period) and 12 months post-treatment (follow-up period).
A single administration of AstroRx® at either low or high doses was safe and well tolerated. No adverse events (AEs) related to AstroRx® itself were reported. Transient AEs related to the Intrathecal (IT) procedure were all mild to moderate. The study demonstrated a clinically meaningful effect that was maintained over the first 3 months after treatment, as measured by the pre-post slope change in ALSFRS-R. In the 100 × 10
AstroRx® arm, the ALSFRS-R rate of deterioration was attenuated from - 0.88/month pre-treatment to - 0.30/month in the first 3 months post-treatment (p = 0.039). In the 250 × 10
AstroRx® arm, the ALSFRS-R slope decreased from - 1.43/month to - 0.78/month (p = 0.0023). The effect was even more profound in a rapid progressor subgroup of 5 patients. No statistically significant change was measured in muscle strength using hand-held dynamometry and slow vital capacity continued to deteriorate during the study.
Overall, these findings suggest that a single IT administration of AstroRx® to ALS patients at a dose of 100 × 10
or 250 × 10
cells is safe. A signal of beneficial clinical effect was observed for the first 3 months following cell injection. These results support further investigation of repeated intrathecal administrations of AstroRx®, e.g., every 3 months.
NCT03482050.
Objective. Previous research suggests that acetylcholinesterase (AChE) may be involved in ALS pathogenesis. AChE enzyme inhibitors can upregulate AChE transcription which in certain contexts can have ...deleterious (noncatalytic) effects, making them theoretically harmful in ALS, whilst AChE antisense-oligonucleotides (mEN101), which downregulate AChE may be beneficial. Our aim was to investigate whether downregulation of AChE using mEN101 is beneficial in an ALS mouse model. Methods. ALS (G93A-SOD1) mice received saline, mEN101, inverse-EN101, or neostigmine. Treatments were administered from 5 weeks. Disease-onset and survival were recorded. Additional mice were sacrificed for pathological analysis at 15 weeks of age. In a follow-up experiment treatment was started at the symptomatic stage at a higher dose. Results. mEN101 given at the presymptomatic (but not symptomatic) stage prolonged survival and attenuated motor-neuron loss in ALS mice. In contrast, neostigmine exacerbated the clinical parameters. Conclusions. These results suggest that AChE may be involved in ALS pathogenesis. The accelerated disease course with neostigmine suggests that any beneficial effects of mEN101 occur through a non-catalytic rather than cholinergic mechanism.
Caveolin-1 and Caveolin-2 (CAV1 and CAV2) are proteins associated with intercellular neurotrophic signalling. There is converging evidence that CAV1 and CAV2 (CAV1/2) genes have a role in amyotrophic ...lateral sclerosis (ALS). Disease-associated variants have been identified within CAV1/2 enhancers, which reduce gene expression and lead to disruption of membrane lipid rafts.
Using large ALS whole-genome sequencing and post-mortem RNA sequencing datasets (5,987 and 365 tissue samples, respectively), and iPSC-derived motor neurons from 55 individuals, we investigated the role of CAV1/2 expression and enhancer variants in the ALS phenotype.
We report a differential expression analysis between ALS cases and controls for CAV1 and CAV2 genes across various post-mortem brain tissues and three independent datasets. CAV1 and CAV2 expression was consistently higher in ALS patients compared to controls, with significant results across the primary motor cortex, lateral motor cortex, and cerebellum. We also identify increased survival among carriers of CAV1/2 enhancer mutations compared to non-carriers within Project MinE and slower progression as measured by the ALSFRS. Carriers showed a median increase in survival of 345 days.
These results add to an increasing body of evidence linking CAV1 and CAV2 genes to ALS. We propose that carriers of CAV1/2 enhancer mutations may be conceptualised as an ALS subtype who present a less severe ALS phenotype with a longer survival duration and slower progression. Upregulation of CAV1/2 genes in ALS cases may indicate a causal pathway or a compensatory mechanism. Given prior research supporting the beneficial role of CAV1/2 expression in ALS patients, we consider a compensatory mechanism to better fit the available evidence, although further investigation into the biological pathways associated with CAV1/2 is needed to support this conclusion.
We established two human embryonic stem cell (hESC) lines with a GGGGCC expansion in the C9orf72 gene (C9), and compared them with haploidentical and unrelated C9 induced pluripotent stem cells ...(iPSCs). We found a marked difference in C9 methylation between the cells. hESCs and parental fibroblasts are entirely unmethylated while the iPSCs are hypermethylated. In addition, we show that the expansion alters promoter usage and interferes with the proper splicing of intron 1, eventually leading to the accumulation of repeat-containing mRNA following neural differentiation. These changes are attenuated in C9 iPSCs, presumably owing to hypermethylation. Altogether, this study highlights the importance of neural differentiation in the pathogenesis of disease and points to the potential role of hypermethylation as a neuroprotective mechanism against pathogenic mRNAs, envisaging a milder phenotype in C9 iPSCs.
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•Derivation of two C9 hESC lines, haploidentical and unrelated C9 iPSCs•Striking difference in C9 methylation and transcription between C9 hESCs and iPSCs•Upregulation of repeat-containing mRNAs by differentiation, exclusively in C9 hESCs•Supports the role for C9 methylation as a neuroprotective mechanism
Eiges and colleagues characterized two C9/ALS-FTD hESC lines, and compared them with haploidentical and unrelated C9 iPSCs. They show that reprogramming excessively hypermethylates the C9 expansion, and provide evidence that when it is unmethylated the expansion enhances accumulation of repeat-containing mRNAs upon differentiation. Their study supports the potential role of C9 hypermethylation as a neuroprotective mechanism in C9-related ALS.
The COVID-19 pandemic presents two main concerns for patients with myasthenia gravis (MG); chronic immunosuppression may put them at greater risk, and some proposed treatments for COVID-19 could ...cause MG exacerbation.
We present three patients with generalized seropositive MG who developed COVID-19. All patients had a favorable outcome, with only one patient experiencing exacerbation. In this case, exacerbation began before COVID-19; she required ICU admission, non-invasive ventilatory support, and received hydroxychloroquine, lopinavir and ritonavir which were well tolerated. One patient received IVIG in place of scheduled plasma exchange.
Outcome was favorable in all cases despite immunosuppressive therapy, use of experimental COVID-19 medication and switching of plasma exchange for IVIG.
•Three cases of myasthenia gravis with COVID-19 with favorable outcome.•Immunosuppressive therapy was continued during COVID-19 infection.•Switching maintenance plasmapheresis with IVIg was well tolerated.
Amyotrophic lateral sclerosis (ALS) is a complex neurodegenerative disorder, in which the clinical manifestations may be influenced by genetic and unknown environmental factors. Here we show that ...ALS-prone Sod1 transgenic (Sod1-Tg) mice have a pre-symptomatic, vivarium-dependent dysbiosis and altered metabolite configuration, coupled with an exacerbated disease under germ-free conditions or after treatment with broad-spectrum antibiotics. We correlate eleven distinct commensal bacteria at our vivarium with the severity of ALS in mice, and by their individual supplementation into antibiotic-treated Sod1-Tg mice we demonstrate that Akkermansia muciniphila (AM) ameliorates whereas Ruminococcus torques and Parabacteroides distasonis exacerbate the symptoms of ALS. Furthermore, Sod1-Tg mice that are administered AM are found to accumulate AM-associated nicotinamide in the central nervous system, and systemic supplementation of nicotinamide improves motor symptoms and gene expression patterns in the spinal cord of Sod1-Tg mice. In humans, we identify distinct microbiome and metabolite configurations-including reduced levels of nicotinamide systemically and in the cerebrospinal fluid-in a small preliminary study that compares patients with ALS with household controls. We suggest that environmentally driven microbiome-brain interactions may modulate ALS in mice, and we call for similar investigations in the human form of the disease.
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