No abstract

Identification of mutations at familial loci for amyotrophic lateral sclerosis (ALS) has provided novel insights into the aetiology of this rapidly progressing fatal neurodegenerative disease. However, genome-wide association studies (GWAS) of the more common (∼90%) sporadic form have been less successful with the exception of the replicated locus at 9p21.2. To identify new loci associated with disease susceptibility, we have established the largest association study in ALS to date and undertaken a GWAS meta-analytical study combining 3959 newly genotyped Italian individuals (1982 cases and 1977 controls) collected by SLAGEN (Italian Consortium for the Genetics of ALS) together with samples from Netherlands, USA, UK, Sweden, Belgium, France, Ireland and Italy collected by ALSGEN (the International Consortium on Amyotrophic Lateral Sclerosis Genetics). We analysed a total of 13 225 individuals, 6100 cases and 7125 controls for almost 7 million single-nucleotide polymorphisms (SNPs). We identified a novel locus with genome-wide significance at 17q11.2 (rs34517613 with P = 1.11 × 10(-8); OR 0.82) that was validated when combined with genotype data from a replication cohort (P = 8.62 × 10(-9); OR 0.833) of 4656 individuals. Furthermore, we confirmed the previously reported association at 9p21.2 (rs3849943 with P = 7.69 × 10(-9); OR 1.16). Finally, we estimated the contribution of common variation to heritability of sporadic ALS as ∼12% using a linear mixed model accounting for all SNPs. Our results provide an insight into the genetic structure of sporadic ALS, confirming that common variation contributes to risk and that sufficiently powered studies can identify novel susceptibility loci.

The induction of mitochondrial biogenesis could potentially alleviate mitochondrial and muscle disease. We show here that dimethyl fumarate (DMF) dose-dependently induces mitochondrial biogenesis and function dosed to cells in vitro, and also dosed in vivo to mice and humans. The induction of mitochondrial gene expression is more dependent on DMF's target Nrf2 than hydroxycarboxylic acid receptor 2 (HCAR2). Thus, DMF induces mitochondrial biogenesis primarily through its action on Nrf2, and is the first drug demonstrated to increase mitochondrial biogenesis with in vivo human dosing. This is the first demonstration that mitochondrial biogenesis is deficient in Multiple Sclerosis patients, which could have implications for MS pathophysiology and therapy. The observation that DMF stimulates mitochondrial biogenesis, gene expression and function suggests that it could be considered for mitochondrial disease therapy and/or therapy in muscle disease in which mitochondrial function is important.

BackgroundFriedreich's ataxia (FRDA) is the most common hereditary ataxia among caucasians. The molecular defect in FRDA is the trinucleotide GAA expansion in the first intron of the FXN gene, which encodes frataxin. No studies have yet reported frataxin protein and mRNA levels in a large cohort of FRDA patients, carriers and controls.Methodology/Principal FindingsWe enrolled 24 patients with classic FRDA phenotype (cFA), 6 late onset FRDA (LOFA), all homozygous for GAA expansion, 5 pFA cases who harbored the GAA expansion in compound heterozygosis with FXN point mutations (namely, p.I154F, c.482+3delA, p.R165P), 33 healthy expansion carriers, and 29 healthy controls. DNA was genotyped for GAA expansion, mRNA/FXN was quantified in real-time, and frataxin protein was measured using lateral-flow immunoassay in peripheral blood mononuclear cells (PBMCs). Mean residual levels of frataxin, compared to controls, were 35.8%, 65.6%, 33%, and 68.7% in cFA, LOFA, pFA and healthy carriers, respectively. Comparison of both cFA and pFA with controls resulted in 100% sensitivity and specificity, but there was overlap between LOFA, carriers and controls. Frataxin levels correlated inversely with GAA1 and GAA2 expansions, and directly with age at onset. Messenger RNA expression was reduced to 19.4% in cFA, 50.4% in LOFA, 52.7% in pFA, 53.0% in carriers, as compared to controls (p<0.0001). mRNA levels proved to be diagnostic when comparing cFA with controls resulting in 100% sensitivity and specificity. In cFA and LOFA patients mRNA levels correlated directly with protein levels and age at onset, and inversely with GAA1 and GAA2.Conclusion/SignificanceWe report the first explorative study on combined frataxin and mRNA levels in PBMCs from a cohort of FRDA patients, carriers and healthy individuals. Lateral-flow immunoassay differentiated cFA and pFA patients from controls, whereas determination of mRNA in q-PCR was sensitive and specific only in cFA.

Amyotrophic lateral sclerosis (ALS) is a fatal neurological disease with motor neuron degeneration. Riluzole is the only available treatment. Two-thirds of ALS patients present with growth hormone (GH) deficiency. The aim of this study is to determine if add-on of GH to riluzole, with an individually regulated dose based on Insulin-like growth factor 1 (IGF-I) production, was able to reduce neuronal loss in the motor cortex, reduce mortality, and improve motor function of ALS patients. Patients with definite/probable ALS, in treatment with riluzole, aged 40-85 years, and with disease duration ≤3 years were enrolled. The study was randomized, placebo controlled, and double blind. Before treatment, patients were tested with a GH releasing hormone (GHRH) + arginine test. The initial dose of GH was 2 IU s.c. every other day, and was progressively increased to a maximum of 8 IU. Primary endpoint was N-acetylaspartate/(creatine + choline) (NAA/Cre + Cho) ratio in motor cortex assessed by magnetic resonance spectroscopy performed at months 0, 6, and 12. Secondary endpoints were mortality and ALS functional rating scale revised (ALSFRS-R). The NAA/(Cre + Cho) ratio decreased in all patients who completed the trial. No significant difference was noted between treated and placebo group. At baseline, although IGF-I levels were within the normal range, 73% of patients had GH deficiency, being severe in half of them. Compared with bulbar onset, spinal-onset patients showed more depressed GH response to the GHRH + arginine stimulation test (10.4 ± 7.0 versus 15.5 ± 8.1 ng/mL; p < 0.05). Insulin resistance [homeostasis model assessment of insulin resistance (HOMA-IR)] increased from 2.1 ± 1.0 at baseline to 4.6 ± 1.9 at 12 months (p < 0.001). Insulin-like growth factor (IGF) binding protein 3 (IGFBP-3) decreased from 8,435 ± 4,477 ng/mL at baseline to 3,250 ± 1,780 ng/mL at 12 months (p < 0.001). The results show that GH exerted no effect on cerebral NAA or clinical progression assessed by ALSFRS-R. Two-thirds of ALS patients had GH deficit, with higher levels in the bulbar-onset group. During follow-up, patients showed progressive increase in HOMA-IR and decrease in IGFBP-3 levels.

Approximately 30% of schizophrenia patients do not respond adequately to the therapy. Previous MRI studies have suggested that drug treatment resistance is associated with brain morphological abnormalities, although region-of-interest analysis of MR studies from nonresponder and responder patients failed to demonstrate a statistically significant difference between these two schizophrenia subgroups. We have used a voxel-based analysis of segmented MR studies to assess structural cerebral differences in 20 nonresponder and 15 responder patients and 16 age-matched normal volunteers. Differences between the three groups emerged bilaterally mainly at the level of the superior and middle frontal gyri, primarily due to reduced grey matter volumes in nonresponders, as compared to both normal volunteers and responder patients. Post hoc direct comparison between the two schizophrenia subgroups demonstrated significantly reduced grey matter volumes in middle frontal gyrus bilaterally, in the dorsolateral aspects of left superior frontal gyrus extending into postcentral gyrus and in the right medial temporal cortex. Our results extend and integrate previous findings suggesting a more severe atrophy in nonresponder schizophrenia patients, compared to responder patients, mainly at the level of the superior and middle frontal gyri. Longitudinal studies in drug-naïve patients are needed to assess the role of these associations.

Friedreich ataxia (FRDA) is caused by a GAA expansion in the first intron of the FXN gene, which encodes frataxin. Four percent of patients harbor a point mutation on one allele and a GAA expansion on the other. We studied an Italian patient presenting with symptoms suggestive of FRDA, and carrying a single expanded 850 GAA allele. As a second diagnostic step, frataxin was measured in peripheral blood mononuclear cells, and proved to be in the pathological range (2.95 pg/μg total protein, 12.7 % of control levels). Subsequent sequencing revealed a novel deletion in exon 5a (c.572delC) which predicted a frameshift at codon 191 and a premature truncation of the protein at codon 194 (p.T191IfsX194). FXN/mRNA expression was reduced to 69.2 % of control levels. Clinical phenotype was atypical with absent dysarthria, and rapid disease progression. L-Buthionine-sulphoximine treatment of the proband's lymphoblasts showed a severe phenotype as compared to classic FRDA.

Objective of the study was to test the efficacy, safety, and tolerability of two single doses of Epoetin alfa in patients with Friedreich's ataxia. Ten patients were treated subcutaneously with 600 IU/kg for the first dose, and 3 months later with 1200 IU/kg. Epoetin alfa had no acute effect on frataxin, whereas a delayed and sustained increase in frataxin was evident at 3 months after the first dose (+35%; P < 0.05), and up to 6 months after the second dose (+54%; P < 0.001). The treatment was well tolerated and did not affect hematocrit, cardiac function, and neurological scale. Single high dose of Epoetin alfa can produce a considerably larger and sustained effect when compared with low doses and repeated administration schemes previously adopted. In addition, no hemoglobin increase was observed, and none of our patients required phlebotomy, indicating lack of erythropoietic effect of single high dose of erythropoietin.