Defining the phenotype of FHF1 developmental and epileptic encephalopathy.

Fibroblast growth-factor homologous factor (FHF1) gene variants have recently been associated with developmental and epileptic encephalopathy (DEE). FHF1 encodes a cytosolic protein that modulates neuronal sodium channel gating. We aim to refine the electroclinical phenotypic spectrum of patients with pathogenic FHF1 variants. We retrospectively collected clinical, genetic, neurophysiologic, and neuroimaging data of 17 patients with FHF1-DEE. Sixteen patients had recurrent heterozygous FHF1 missense variants: 14 had the recurrent p.Arg114His variant and two had a novel likely pathogenic variant p.Gly112Ser. The p.Arg114His variant is associated with an earlier onset and more severe phenotype. One patient carried a chromosomal microduplication involving FHF1. Twelve patients carried a de novo variant, five (29.5%) inherited from parents with gonadic or somatic mosaicism. Seizure onset was between 1 day and 41 months; in 76.5% it was within 30 days. Tonic seizures were the most frequent seizure type. Twelve patients (70.6%) had drug-resistant epilepsy, 14 (82.3%) intellectual disability, and 11 (64.7%) behavioral disturbances. Brain magnetic resonance imaging (MRI) showed mild cerebral and/or cerebellar atrophy in nine patients (52.9%). Overall, our findings expand and refine the clinical, EEG, and imaging phenotype of patients with FHF1-DEE, which is characterized by early onset epilepsy with tonic seizures, associated with moderate to severe ID and psychiatric features.

Efficacy of idebenone on respiratory function in patients with Duchenne muscular dystrophy not using glucocorticoids (DELOS): a double-blind randomised placebo-controlled phase 3 trial.

BACKGROUND: Cardiorespiratory failure is the leading cause of death in Duchenne muscular dystrophy. Based on preclinical and phase 2 evidence, we assessed the efficacy and safety of idebenone in young patients with Duchenne muscular dystrophy who were not taking concomitant glucocorticoids. METHODS: In a multicentre phase 3 trial in Belgium, Germany, the Netherlands, Switzerland, France, Sweden, Austria, Italy, Spain, and the USA, patients (age 10-18 years old) with Duchenne muscular dystrophy were randomly assigned in a one-to-one ratio with a central interactive web response system with a permuted block design with four patients per block to receive idebenone (300 mg three times a day) or matching placebo orally for 52 weeks. Study personnel and patients were masked to treatment assignment. The primary endpoint was change in peak expiratory flow (PEF) as percentage predicted (PEF%p) from baseline to week 52, measured with spirometry. Analysis was by intention to treat (ITT) and a modified ITT (mITT), which was prospectively defined to exclude patients with at least 20% difference in the yearly change in PEF%p, measured with hospital-based and weekly home-based spirometry. This study is registered with ClinicalTrials.gov, number NCT01027884. FINDINGS: 31 patients in the idebenone group and 33 in the placebo group comprised the ITT population, and 30 and 27 comprised the mITT population. Idebenone significantly attenuated the fall in PEF%p from baseline to week 52 in the mITT (-3·05%p [95% CI -7·08 to 0·97], p=0·134, vs placebo -9·01%p [-13·18 to -4·84], p=0·0001; difference 5·96%p [0·16 to 11·76], p=0·044) and ITT populations (-2·57%p [-6·68 to 1·54], p=0·215, vs -8·84%p [-12·73 to -4·95], p<0·0001; difference 6·27%p [0·61 to 11·93], p=0·031). Idebenone also had a significant effect on PEF (L/min), weekly home-based PEF, FVC, and FEV1. The effect of idebenone on respiratory function outcomes was similar between patients with previous corticosteroid use and steroid-naive patients. Treatment with idebenone was safe and well tolerated with adverse event rates were similar in both groups. Nasopharyngitis and headache were the most common adverse events (idebenone, eight [25%] and six [19%] of 32 patients; placebo, nine [26%] and seven [21%] of 34 patients). Transient and mild diarrhoea was more common in the idebenone group than in the placebo group (eight [25%] vs four [12%] patients). INTERPRETATION: Idebenone reduced the loss of respiratory function and represents a new treatment option for patients with Duchenne muscular dystrophy. FUNDING: Santhera Pharmaceuticals.

The contribution of platelet studies to the understanding of disease mechanisms in complex and monogenetic neurological disorders.

Platelets, known for their role in primary haemostasis, prevent excessive bleeding after injury. The study of platelets has, therefore, traditionally focused on bleeding disorders. It has recently become evident, however, that platelet research can contribute to unravelling the disease mechanisms that underlie neuropathological disorders that have a subtle subclinical platelet phenotype. Platelets and neurosecretory cells have common gene expression profiles and share several biological features. This review provides a literature update on the use of platelets as easily accessible cells to study neurological disorders. We provide examples of the use of different platelet-based tests to understand the underlying pathophysiological mechanisms for both complex and monogenetic neuropathological disorders. In addition to the well-studied regulated granule secretion and serotonin metabolism, more recent studies have shown that defects in transcription factors, membrane transporters, G-protein signal transduction, and cytoskeletal proteins can be investigated using platelets to gain information on their role in neuropathology.

Homozygosity for aquaporin 7 G264V in three unrelated children with hyperglyceroluria and a mild platelet secretion defect.

PURPOSE: Aquaporin 7 (AQP7) belongs to the aquaglyceroporin family, which transports glycerol and water. AQP7-deficient mice develop obesity, insulin resistance, and hyperglyceroluria. However, AQP7's pathophysiologic role in humans is not yet known. METHODS: Three children with psychomotor retardation and hyperglyceroluria were screened for AQP7 mutations. The children were from unrelated families. Urine and plasma glycerol levels were measured using a three-step enzymatic approach. Platelet morphology and function were studied using electron microscopy, aggregations, and adenosine triphosphate (ATP) secretion tests. RESULTS: The index patients were homozygous for AQP7 G264V, which has previously been shown to inhibit transport of glycerol in Xenopus oocytes. We also detected a subclinical platelet secretion defect with reduced ATP secretion, and the absence of a secondary aggregation wave after epinephrine stimulation. Electron microscopy revealed round platelets with centrally located granules. Immunostaining showed AQP7 colocalization, with dense granules that seemed to be released after strong platelet activation. Healthy relatives of these patients, who were homozygous (not heterozygous) for G264V, also had hyperglyceroluria and platelet granule abnormalities. CONCLUSION: The discovery of an association between urine glycerol loss and a platelet secretion defect is a novel one, and our findings imply the involvement of AQPs in platelet secretion. Additional studies are needed to define whether AQP7 G264V is also a risk factor for mental disability.

Human iPSC model reveals a central role for NOX4 and oxidative stress in Duchenne cardiomyopathy.

Duchenne muscular dystrophy (DMD) is a progressive muscle disorder caused by mutations in the Dystrophin gene. Cardiomyopathy is a major cause of early death. We used DMD-patient-specific human induced pluripotent stem cells (hiPSCs) to model cardiomyopathic features and unravel novel pathologic insights. Cardiomyocytes (CMs) differentiated from DMD hiPSCs showed enhanced premature cell death due to significantly elevated intracellular reactive oxygen species (ROS) resulting from depolarized mitochondria and increased NADPH oxidase 4 (NOX4). CRISPR-Cas9 correction of Dystrophin restored normal ROS levels. ROS reduction by N-acetyl-L-cysteine (NAC), ataluren (PTC124), and idebenone improved hiPSC-CM survival. We show that oxidative stress in DMD hiPSC-CMs was counteracted by stimulating adenosine triphosphate (ATP) production. ATP can bind to NOX4 and partially inhibit the ROS production. Considering the complexity and the early cellular stress responses in DMD cardiomyopathy, we propose targeting ROS production and preventing detrimental effects of NOX4 on DMD CMs as promising therapeutic strategy.

Extracellular vesicle-derived miRNAs improve stem cell-based therapeutic approaches in muscle wasting conditions.

Skeletal muscle holds an intrinsic capability of growth and regeneration both in physiological conditions and in case of injury. Chronic muscle illnesses, generally caused by genetic and acquired factors, lead to deconditioning of the skeletal muscle structure and function, and are associated with a significant loss in muscle mass. At the same time, progressive muscle wasting is a hallmark of aging. Given the paracrine properties of myogenic stem cells, extracellular vesicle-derived signals have been studied for their potential implication in both the pathogenesis of degenerative neuromuscular diseases and as a possible therapeutic target. In this study, we screened the content of extracellular vesicles from animal models of muscle hypertrophy and muscle wasting associated with chronic disease and aging. Analysis of the transcriptome, protein cargo, and microRNAs (miRNAs) allowed us to identify a hypertrophic miRNA signature amenable for targeting muscle wasting, consisting of miR-1 and miR-208a. We tested this signature among others in vitro on mesoangioblasts (MABs), vessel-associated adult stem cells, and we observed an increase in the efficiency of myogenic differentiation. Furthermore, injections of miRNA-treated MABs in aged mice resulted in an improvement in skeletal muscle features, such as muscle weight, strength, cross-sectional area, and fibrosis compared to controls. Overall, we provide evidence that the extracellular vesicle-derived miRNA signature we identified enhances the myogenic potential of myogenic stem cells.

Long-term blinded placebo-controlled study of SNT-MC17/idebenone in the dystrophin deficient mdx mouse: cardiac protection and improved exercise performance.

AIMS: Duchenne muscular dystrophy (DMD) is a severe and still incurable disease, with heart failure as a leading cause of death. The identification of a disease-modifying therapy may require early-initiated and long-term administration, but such type of therapeutic trial is not evident in humans. We have performed such a trial of SNT-MC17/idebenone in the mdx mouse model of DMD, based on the drug's potential to improve mitochondrial respiratory chain function and reduce oxidative stress. METHODS AND RESULTS: In this study, 200 mg/kg bodyweight of either SNT-MC17/idebenone or placebo was given from age 4 weeks until 10 months in mdx and wild-type mice. All evaluators were blinded to mouse type and treatment groups. Idebenone treatment significantly corrected cardiac diastolic dysfunction and prevented mortality from cardiac pump failure induced by dobutamine stress testing in vivo, significantly reduced cardiac inflammation and fibrosis, and significantly improved voluntary running performance in mdx mice. CONCLUSION: We have identified a novel potential therapeutic strategy for human DMD, as SNT-MC17/idebenone was cardioprotective and improved exercise performance in the dystrophin-deficient mdx mouse. Our data also illustrate that the mdx mouse provides unique opportunities for long-term controlled prehuman therapeutic studies.

Long-term data with idebenone on respiratory function outcomes in patients with Duchenne muscular dystrophy.

Decline in respiratory function in patients with DMD starts during early teenage years and leads to early morbidity and mortality. Published evidence of efficacy for idebenone on respiratory function outcomes is currently limited to 12 months of follow-up time. Here we report data collected as retrospective cohort study (SYROS) from 18 DMD patients not using glucocorticoids who were treated with idebenone (900 mg/day) under Expanded Access Programs (EAPs). The objective was to assess the long-term respiratory function evolution for periods On-Idebenone compared to periods Off-Idebenone in the same patients. The mean idebenone exposure in the EAPs was 4.2 (range 2.4-6.1) years. The primary endpoint was the annual change in forced vital capacity percent of predicted (FVC%p) compared between Off-Idebenone and On-Idebenone periods. The annual rate of decline in FVC%p was reduced by approximately 50% from -7.4% (95% CI: -9.1, -5.8) for the Off-Idebenone periods to -3.8% (95% CI: -4.8, -2.8) for the On-Idebenone periods (N = 11). Similarly, annual change in peak expiratory flow percent of predicted (PEF%p) was -5.9% (95% CI: -8.0, -3.9) for the Off-Idebenone periods (N = 9) and reduced to -1.9% (95% CI: -3.2, -0.7) for the On-Idebenone periods during the EAPs. The reduced rates of decline in FVC%p and PEF%p were maintained for several years with possible beneficial effects on the rate of bronchopulmonary adverse events, time to 10% decline in FVC%p and risk of hospitalization due to respiratory cause. These long-term data provide Class IV evidence to further support the disease modifying treatment effect of idebenone previously observed in randomized, controlled trials.

Dystrophin deficiency leads to dysfunctional glutamate clearance in iPSC derived astrocytes.

Duchenne muscular dystrophy (DMD) results, beside muscle degeneration in cognitive defects. As neuronal function is supported by astrocytes, which express dystrophin, we hypothesized that loss of dystrophin from DMD astrocytes might contribute to these cognitive defects. We generated cortical neuronal and astrocytic progeny from induced pluripotent stem cells (PSC) from six DMD subjects carrying different mutations and several unaffected PSC lines. DMD astrocytes displayed cytoskeletal abnormalities, defects in Ca+2 homeostasis and nitric oxide signaling. In addition, defects in glutamate clearance were identified in DMD PSC-derived astrocytes; these deficits were related to a decreased neurite outgrowth and hyperexcitability of neurons derived from healthy PSC. Read-through molecule restored dystrophin expression in DMD PSC-derived astrocytes harboring a premature stop codon mutation, corrected the defective astrocyte glutamate clearance and prevented associated neurotoxicity. We propose a role for dystrophin deficiency in defective astroglial glutamate homeostasis which initiates defects in neuronal development.

Home-Based Monitoring of Pulmonary Function in Patients with Duchenne Muscular Dystroph.

BACKGROUND: Loss of pulmonary function is a main cause of early morbidity and mortality in patients with Duchenne muscular dystrophy (DMD). Standard of care guidelines recommend regular assessment of pulmonary function by hospital-based spirometry to detect onset and monitor progression of pulmonary function decline. OBJECTIVE: To assess the feasibility of home-based monitoring of pulmonary function by a hand-held device (HHD) in adolescent and adult patients with DMD over a period of 12 months. METHODS: In the phase III randomized placebo-controlled DELOS trial in 10-18 year old DMD patients, peak expiratory flow (PEF) measurements were collected weekly at home by the patient (assisted by parent/caregiver) using a peak flow meter HHD. Adherence to the use of the HHD was assessed and 12-month changes in PEF as percent of predicted (PEF% p) for the idebenone (N = 31) and the placebo treatment groups (N = 33) from HHD-derived data were compared to results from hospital-based spirometry. RESULTS: A total of 2689 individual HHD assessments were analysed. Overall adherence to the use of the HHD over the course of the 12-month study duration was good (75.9%, SD 21.5%) and PEF% p data obtained at the same day by HHD and standard spirometry correlated well (Spearman's rho 0.80; p < 0.001). Several analysis methods of HHD-derived data for PEF% p consistently demonstrate that idebenone treatment slowed the decline in PEF% p compared to placebo, which supports the statistically significant difference in favour of idebenone for PEF% p measured by standard spirometry. CONCLUSIONS: This study demonstrates that home-based monitoring of pulmonary function in adolescent patients with DMD using a HHD is feasible, provides reliable data compared to hospital-based spirometry and is therefore suitable for use in clinical practice and for clinical trials.

CINRG pilot trial of oxatomide in steroid-naïve Duchenne muscular dystrophy.

The authors report a pilot open-label two-center therapeutic trial of oxatomide in 14 steroid-naive DMD boys aged 5-10 years. Comparison of linear evolutions between 3 months medication-free lead-in periods and 6 months treatment periods showed no significant differences in quantitative (QMT) and manual (MMT) measurements of muscle strength and timed functional tests. A modest mitigation of strength deterioration over time cannot be excluded.

Efficacy of Idebenone to Preserve Respiratory Function above Clinically Meaningful Thresholds for Forced Vital Capacity (FVC) in Patients with Duchenne Muscular Dystrophy.

BACKGROUND: Patients with DMD experience progressive restrictive respiratory disease and eventual respiratory failure. Standard of care guidelines command changes in disease management when forced vital capacity percent of predicted (FVC% p) falls below clinically relevant thresholds. The Phase 3 DELOS trial in patients with DMD demonstrated that idebenone reduces the loss of peak expiratory flow and FVC compared to placebo (Buyse GM, et al.; Lancet 2015; 385 : 1748-57). OBJECTIVE: Post-hoc analyses were conducted to assess whether treatment with idebenone could reduce the risk of patients dropping below clinically meaningful thresholds of FVC% p. METHODS: The DELOS trial enrolled DMD patients 10-18 years of age not using glucocorticoids to receive idebenone (N = 31) or placebo (N = 33) for 12 months. Change from baseline in FVC and FVC% p was assessed by hospital spirometry and analyzed by mixed model of repeated measures and slope analysis and proportions of patients falling below clinically meaningful thresholds of FVC% p were compared. RESULTS: The change over 1 year in FVC and FVC% p showed a consistent pattern in favor of idebenone treatment across multiple analysis methods and fewer patients in the idebenone group declined by a margin of 10% or more in FVC and FVC% p compared to placebo. There were also fewer patients in the idebenone group (15%) with a decline below FVC% p of 50% compared to the placebo group (25%) and fewer patients in the idebenone group (28%) showed a decline below FVC% p of 50% or 40% or 30% compared to the placebo group (43%). CONCLUSIONS: These data added to the consistency and clinical meaningfulness of findings from the DELOS trial showing that idebenone can slow the loss of pulmonary function in patients with DMD.

Characterization of pulmonary function in 10-18 year old patients with Duchenne muscular dystrophy.

Pulmonary function loss in patients with Duchenne muscular dystrophy (DMD) is progressive and leads to pulmonary insufficiency. The purpose of this study in 10-18 year old patients with DMD is the assessment of the inter-correlation between pulmonary function tests (PFTs), their reliability and the association with the general disease stage measured by the Brooke score. Dynamic PFTs (peak expiratory flow [PEF], forced vital capacity [FVC], forced expiratory volume in one second [FEV1]) and maximum static airway pressures (MIP, MEP) were prospectively collected from 64 DMD patients enrolled in the DELOS trial (ClinicalTrials.gov, number NCT01027884). Baseline PEF percent predicted (PEF%p) was <80% and patients had stopped taking glucocorticoids at least 12 months prior to study start. At baseline PEF%p, FVC%p and FEV1%p correlated well with each other (Spearman's rho: PEF%p-FVC%p: 0.54; PEF%p-FEV1%p: 0.72; FVC%p-FEV1%p: 0.91). MIP%p and MEP%p correlated well with one another (MIP%p-MEP%p: 0.71) but less well with PEF%p (MIP%p-PEF%p: 0.40; MEP%p-PEF%p: 0.41) and slightly better with FVC%p (MIP%p-FVC%p: 0.59; MEP%p-FVC%p: 0.74). The within-subject coefficients of variation (CV) for successive measures were 6.97% for PEF%p, 6.69% for FVC%p and 11.11% for FEV1%p, indicating that these parameters could be more reliably assessed compared to maximum static airway pressures (CV for MIP%p: 18.00%; MEP%p: 15.73%). Yearly rates of PFT decline (placebo group) were larger in dynamic parameters (PEF%p: -8.9% [SD 2.0]; FVC%p: -8.7% [SD 1.1]; FEV1%p: -10.2% [SD 2.0]) than static airway pressures (MIP%p: -4.5 [SD 1.3]; MEP%p: -2.8 [SD 1.1]). A considerable drop in dynamic pulmonary function parameters was associated with loss of upper limb function (transition from Brooke score category 4 to category 5). In conclusion, these findings expand the understanding of the reliability, correlation and evolution of different pulmonary function measures in DMD patients who are in the pulmonary function decline phase.

Activin A Modulates CRIPTO-1/HNF4α+ Cells to Guide Cardiac Differentiation from Human Embryonic Stem Cells.

The use of human pluripotent stem cells in basic and translational cardiac research requires efficient differentiation protocols towards cardiomyocytes. In vitro differentiation yields heterogeneous populations of ventricular-, atrial-, and nodal-like cells hindering their potential applications in regenerative therapies. We described the effect of the growth factor Activin A during early human embryonic stem cell fate determination in cardiac differentiation. Addition of high levels of Activin A during embryoid body cardiac differentiation augmented the generation of endoderm derivatives, which in turn promoted cardiomyocyte differentiation. Moreover, a dose-dependent increase in the coreceptor expression of the TGF-ß superfamily member CRIPTO-1 was observed in response to Activin A. We hypothesized that interactions between cells derived from meso- and endodermal lineages in embryoid bodies contributed to improved cell maturation in early stages of cardiac differentiation, improving the beating frequency and the percentage of contracting embryoid bodies. Activin A did not seem to affect the properties of cardiomyocytes at later stages of differentiation, measuring action potentials, and intracellular Ca2+ dynamics. These findings are relevant for improving our understanding on human heart development, and the proposed protocol could be further explored to obtain cardiomyocytes with functional phenotypes, similar to those observed in adult cardiac myocytes.

Treatment effect of idebenone on inspiratory function in patients with Duchenne muscular dystrophy.

Assessment of dynamic inspiratory function may provide valuable information about the degree and progression of pulmonary involvement in patients with Duchenne muscular dystrophy (DMD). The aims of this study were to characterize inspiratory function and to assess the efficacy of idebenone on this pulmonary function outcome in a large and well-characterized cohort of 10-18 year-old DMD patients not taking glucocorticoid steroids (GCs) enrolled in the phase 3 randomized controlled DELOS trial. We evaluated the effect of idebenone on the highest flow generated during an inspiratory FVC maneuver (maximum inspiratory flow; V'I,max(FVC)) and the ratio between the largest inspiratory flow during tidal breathing (tidal inspiratory flow; V'I,max(t)) and the V'I,max(FVC). The fraction of the maximum flow that is not used during tidal breathing has been termed inspiratory flow reserve (IFR). DMD patients in both treatment groups of DELOS (idebenone, n = 31; placebo: n = 33) had comparable and abnormally low V'I,max(FVC) at baseline. During the study period, V'I,max(FVC) further declined by -0.29 L/sec in patients on placebo (95%CI: -0.51, -0.08; P = 0.008 at week 52), whereas it remained stable in patients on idebenone (change from baseline to week 52: 0.01 L/sec; 95%CI: -0.22, 0.24; P = 0.950). The between-group difference favoring idebenone was 0.27 L/sec (P = 0.043) at week 26 and 0.30 L/sec (P = 0.061) at week 52. In addition, during the study period, IFR improved by 2.8% in patients receiving idebenone and worsened by -3.0% among patients on placebo (between-group difference 5.8% at week 52; P = 0.040). Although the clinical interpretation of these data is currently limited due to the scarcity of routine clinical practice experience with dynamic inspiratory function outcomes in DMD, these findings from a randomized controlled study nevertheless suggest that idebenone preserved inspiratory muscle function as assessed by V'I,max(FVC) and IFR in patients with DMD. Pediatr Pulmonol. 2017;52:508-515. © 2016 The Authors. Pediatric Pulmonology Published by Wiley Periodicals, Inc.

Gain-of-function FHF1 mutation causes early-onset epileptic encephalopathy with cerebellar atrophy.

OBJECTIVE: Voltage-gated sodium channel (Nav)-encoding genes are among early-onset epileptic encephalopathies (EOEE) targets, suggesting that other genes encoding Nav-binding proteins, such as fibroblast growth factor homologous factors (FHFs), may also play roles in these disorders. METHODS: To identify additional genes for EOEE, we performed whole-exome sequencing in a family quintet with 2 siblings with a lethal disease characterized by EOEE and cerebellar atrophy. The pathogenic nature and functional consequences of the identified sequence alteration were determined by electrophysiologic studies in vitro and in vivo. RESULTS: A de novo heterozygous missense mutation was identified in the FHF1 gene (FHF1AR114H, FHF1BR52H) in the 2 affected siblings. The mutant FHF1 proteins had a strong gain-of-function phenotype in transfected Neuro2A cells, enhancing the depolarizing shifts in Nav1.6 voltage-dependent fast inactivation, predicting increased neuronal excitability. Surprisingly, the gain-of-function effect is predicted to result from weaker interaction of mutant FHF1 with the Nav cytoplasmic tail. Transgenic overexpression of mutant FHF1B in zebrafish larvae enhanced epileptiform discharges, demonstrating the epileptic potential of this FHF1 mutation in the affected children. CONCLUSIONS: Our data demonstrate that gain-of-function FHF mutations can cause neurologic disorder, and expand the repertoire of genetic causes (FHF1) and mechanisms (altered Nav gating) underlying EOEE and cerebellar atrophy.

Idebenone reduces respiratory complications in patients with Duchenne muscular dystrophy.

In Duchenne muscular dystrophy (DMD), progressive loss of respiratory function leads to restrictive pulmonary disease and places patients at significant risk for severe respiratory complications. Of particular concern are ineffective cough, secretion retention and recurrent respiratory tract infections. In a Phase 3 randomized controlled study (DMD Long-term Idebenone Study, DELOS) in DMD patients 10-18 years of age and not taking concomitant glucocorticoid steroids, idebenone (900 mg/day) reduced significantly the loss of respiratory function over a 1-year study period. In a post-hoc analysis of DELOS we found that more patients in the placebo group compared to the idebenone group experienced bronchopulmonary adverse events (BAEs): placebo: 17 of 33 patients, 28 events; idebenone: 6 of 31 patients, 7 events. The hazard ratios (HR) calculated "by patient" (HR 0.33, p = 0.0187) and for "all BAEs" (HR 0.28, p = 0.0026) indicated a clear idebenone treatment effect. The overall duration of BAEs was 222 days (placebo) vs. 82 days (idebenone). In addition, there was also a difference in the use of systemic antibiotics utilized for the treatment of BAEs. In the placebo group, 13 patients (39.4%) reported 17 episodes of antibiotic use compared to 7 patients (22.6%) reporting 8 episodes of antibiotic use in the idebenone group. Furthermore, patients in the placebo group used systemic antibiotics for longer (105 days) compared to patients in the idebenone group (65 days). This post-hoc analysis of DELOS indicates that the protective effect of idebenone on respiratory function is associated with a reduced risk of bronchopulmonary complications and a reduced need for systemic antibiotics.

Regulated granule trafficking in platelets and neurons: a common molecular machinery.

Platelet function in primary hemostasis involves the secretion of granules upon activation, providing the localized delivery of effector proteins at sites of vascular injury. The sequential process of regulated secretion in platelets, from the biogenesis of the granules, through their transport and up to the exocytotic fusion process at the acceptor membrane, involves a complex molecular machinery conserved between some other specialized cells such as neurons. Mutations in genes encoding proteins involved in this process of granule trafficking have helped towards demystification of the underlying secretory mechanisms. Human diseases of trafficking encompass a broad symptomatology including a platelet-related bleeding diathesis and neuronal problems. In this review, we want to highlight the similarities in granule biology between platelets and neurons and further focus on some granule trafficking disorders that result in bleeding and neuropathology. This review provides evidence that platelet research can be expanded from traditional studies of isolated thrombopathies to the field of neuropathologies that include a platelet secretion defect.

Effects of glucocorticoids and idebenone on respiratory function in patients with duchenne muscular dystrophy.

In Duchenne muscular dystrophy (DMD) progressive weakness of respiratory muscles leads to a restrictive pulmonary syndrome that contributes to early morbidity and mortality. Currently no curative treatment exists for DMD. In a Phase II randomized placebo-controlled study (DELPHI) in 21 DMD boys at age 8-16 years, idebenone (450 mg/d) showed trends of efficacy for cardiac and respiratory endpoints. Since the DELPHI study population comprised both glucocorticoid-naïve subjects and glucocorticoid-users, we now report a post-hoc analysis investigating the effects of glucocorticoids and idebenone on markers of respiratory weakness, particularly peak expiratory flow (PEF) percent predicted (PEF%p). Baseline values of PEF%p correlated well with the percent predicted values for maximal inspiratory mouth pressure (MIP%p), forced vital capacity (FVC%p), and forced expired volume in 1 sec (FEV1%p). Baseline PEF%p and FVC%p were significantly higher in patients on concomitant glucocorticoids compared to glucocorticoid-naïve patients. In the latter subgroup, idebenone caused a 8.0 ± 12.1% improvement in PEF%p, whilst patients on placebo declined by -12.3 ± 17.9% (P < 0.05) in the course of the 12 month study. In patients receiving concomitant glucocorticoids, PEF%p remained stable (-0.4 ± 14.6%) in the idebenone group compared to a decline by -6.2 ± 12.4% (P = 0.24) in the placebo group. Idebenone showed a trend for efficacy on FVC%p only in glucocorticoid-naïve patients. Because of the study limitations, these data are exploratory and preclude any firm conclusions. In conclusion, PEF appears to be a sensitive respiratory function parameter that could be a valid and clinically relevant endpoint in intervention studies in DMD. In DELPHI the effect size of idebenone on PEF%p was significantly larger in steroid-naive patients, possibly indicating a maximum treatment effect reached by steroids or steroid-mediated suppression of idebenone's effects. The impact of standard care glucocorticoids on respiratory function will have to be considered in the planning of future interventional trials in DMD.