[Show abstract][Hide abstract] ABSTRACT: To assess the safety, tolerability, and preliminary efficacy of NP001, a novel immune regulator of inflammatory monocytes/macrophages, for slowing progression of amyotrophic lateral sclerosis (ALS).
This was a phase 2 randomized, double-blind, placebo-controlled trial of NP001 in 136 patients with ALS of <3 years' duration and forced vital capacity ≥70%. Participants received NP001 2 mg/kg, NP001 1 mg/kg, or placebo for 6 months. Safety, tolerability, and inflammatory biomarkers were assessed throughout the study. Preliminary efficacy was evaluated using the ALS Functional Rating Scale-Revised (ALSFRS-R) slope and change from baseline, with and without matched historical placebo controls, after 6 months of treatment. A post hoc analysis of the percentage of patients ("responders") whose ALSFRS-R did not change from baseline was also conducted.
NP001 was generally safe and well-tolerated, except for infusion site pain and dizziness. No significant slowing of decline in the primary or secondary measures was observed. However, slowing of progression was observed in the high-dose group in patients with greater inflammation (wide range C-reactive protein). Moreover, NP001 may have dose dependently halted symptom progression in a subset of patients. More than 2 times as many patients on high-dose NP001 (25%) did not progress during 6 months of treatment compared with those on placebo (11%). Most "responders" had an elevated biomarker of inflammation, interleukin-18, and were positive for lipopolysaccharide at baseline, which decreased after treatment with NP001.
The arresting of progression of ALS symptoms by NP001 in a subset of patients with marked neuroinflammation, as observed here, will represent a novel therapeutic approach for patients with ALS, if confirmed.
This study provides Class I evidence that for patients with ALS, NP001 is safe and did not significantly slow progression of the disease (difference in slope of the ALSFRS-R/month 0.12 favoring NP001, p = 0.55). The study lacks the precision to exclude an important effect of NP001.
[Show abstract][Hide abstract] ABSTRACT: The discovery of an expanded non-coding GGGGCC repeat expansion in the c9orf72 gene as the most common genetic cause of ALS and FTD (c9ALS/FTD) spurred the recent development of novel cellular and animal models recapitulating key disease features. However, the majority of models currently available have limitations. For example, overexpressing the expansion produces two disease hallmarks, RNA foci formation and repeat-associated non-ATG (RAN) translation, but not reduced expression of c9ORF72 mRNA and protein as seen in c9ALS/FTD patients. Potentially important events resulting from the expansion of the repeat within genomic DNA may be not present in the overexpression models. Moreover, it is technically difficult to clone a repeat sequence that would be similar in length to those observed in patients. To overcome such challenges, we present a method to transdifferentiate patients` dermal fibroblasts using a previously published vector encoding short hairpin RNA targeting polypyrimidine-tract-binding protein 1 (PTB1). PTB1 has been shown to inhibit neuronal differentiation triggered by miR-124 resulting in a cascade involving proneuronal alternative splicing events. We developed a protocol for a 2-week direct conversion of dermal fibroblasts to functional, induced neurons (iNeurons). The iNeurons generated from c9ALS/FTD patients formed more intranuclear RNA foci than fibroblasts and expressed RANT products (not detected in the parental fibroblasts). Moreover, we tested antisense short oligonucleotides (ASOs) targeting the pathogenic GGGGCC expansion in these cells and observed significant reductions in RNA foci, RANT product accumulation and cell toxicity. Taken together, our studies suggest iNeurons provide a fast and efficient tool for screening therapies.
9th International Conference on Frontotemporal Dementias, Vancouver, Canada; 10/2014
[Show abstract][Hide abstract] ABSTRACT: Individuals carrying (GGGGCC) expanded repeats in the C9orf72 gene represent a significant portion of patients suffering from amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Elucidating how these expanded repeats cause "c9FTD/ALS" has since become an important goal of the field. Toward this end, we sought to investigate whether epigenetic changes are responsible for the decrease in C9orf72 expression levels observed in c9FTD/ALS patients. We obtained brain tissue from ten c9FTD/ALS individuals, nine FTD/ALS cases without a C9orf72 repeat expansion, and nine disease control participants, and generated fibroblastoid cell lines from seven C9orf72 expanded repeat carriers and seven participants carrying normal alleles. Chromatin immunoprecipitation using antibodies for histone H3 and H4 trimethylated at lysines 9 (H3K9), 27 (H3K27), 79 (H3K79), and 20 (H4K20) revealed that these trimethylated residues bind strongly to C9orf72 expanded repeats in brain tissue, but not to non-pathogenic repeats. Our finding that C9orf72 mRNA levels are reduced in the frontal cortices and cerebella of c9FTD/ALS patients is consistent with trimethylation of these histone residues, an event known to repress gene expression. Moreover, treating repeat carrier-derived fibroblasts with 5-aza-2-deoxycytidine, a DNA and histone demethylating agent, not only decreased C9orf72 binding to trimethylated histone residues, but also increased C9orf72 mRNA expression. Our results provide compelling evidence that trimethylation of lysine residues within histones H3 and H4 is a novel mechanism involved in reducing C9orf72 mRNA expression in expanded repeat carriers. Of importance, we show that mutant C9orf72 binding to trimethylated H3K9 and H3K27 is detectable in blood of c9FTD/ALS patients. Confirming these exciting results using blood from a larger cohort of patients may establish this novel epigenetic event as a biomarker for c9FTD/ALS.
[Show abstract][Hide abstract] ABSTRACT: Algorithms designed to identify canonical yeast prions predict that around 250 human proteins, including several RNA-binding proteins associated with neurodegenerative disease, harbour a distinctive prion-like domain (PrLD) enriched in uncharged polar amino acids and glycine. PrLDs in RNA-binding proteins are essential for the assembly of ribonucleoprotein granules. However, the interplay between human PrLD function and disease is not understood. Here we define pathogenic mutations in PrLDs of heterogeneous nuclear ribonucleoproteins (hnRNPs) A2B1 and A1 in families with inherited degeneration affecting muscle, brain, motor neuron and bone, and in one case of familial amyotrophic lateral sclerosis. Wild-type hnRNPA2 (the most abundant isoform of hnRNPA2B1) and hnRNPA1 show an intrinsic tendency to assemble into self-seeding fibrils, which is exacerbated by the disease mutations. Indeed, the pathogenic mutations strengthen a ‘steric zipper’ motif in the PrLD, which accelerates the formation of self-seeding fibrils that cross-seed polymerization of wild-type hnRNP. Notably, the disease mutations promote excess incorporation of hnRNPA2 and hnRNPA1 into stress granules and drive the formation of cytoplasmic inclusions in animal models that recapitulate the human pathology. Thus, dysregulated polymerization caused by a potent mutant steric zipper motif in a PrLD can initiate degenerative disease. Related proteins with PrLDs should therefore be considered candidates for initiating and perhaps propagating proteinopathies of muscle, brain, motor neuron and bone.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: The phosphorylated neurofilament heavy subunit (pNF-H), a major structural component of motor axons, is a promising putative biomarker in amyotrophic lateral sclerosis (ALS) but has been studied mainly in CSF. We examined pNF-H concentrations in plasma, serum and CSF as a potential biomarker for disease progression and survival in ALS. METHODOLOGY: We measured pNF-H concentration by monoclonal sandwich ELISA in plasma (n=43), serum and CSF (n=20) in ALS patients collected at the Mayo Clinic Florida and Emory University. We included plasma from an ALS cohort (n=20) from an earlier pilot study in order to evaluate baseline pNF-H levels in relation to disease progression using the Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R), survival and anatomical region of ALS onset. RESULTS: Higher pNF-H levels in plasma, serum and CSF showed evidence of association with faster decline in ALSFRS-R. There was evidence for a relationship of higher serum and plasma pNF-H levels with shorter survival, although evidence was weaker for CSF. pNF-H concentration in plasma (n=62) may be higher in patients with bulbar onset than in patients with spinal onset. CONCLUSIONS: In ALS, increased pNF-H concentration in plasma, serum and CSF appears to be associated with faster disease progression. Factors affecting pNF-H levels or their detection in serum and plasma in relation to disease course may differ from those in CSF. Data raising the possibility that site of ALS onset (bulbar vs spinal) may influence pNF-H levels in peripheral blood seems noteworthy but requires confirmation. These data support further study of pNF-H in CSF, serum and plasma as a potential ALS biomarker.
Journal of neurology, neurosurgery, and psychiatry 10/2012; 84(4). DOI:10.1136/jnnp-2012-303768 · 5.58 Impact Factor