Mutation in superoxide dismutase-1 (SOD1), which is a cause of ALS, alters the folding patterns of this protein. Accumulation of misfolded mutant SOD1 might activate endoplasmic reticulum (ER) stress pathways. Here we show that transgenic mice expressing ALS-linked SOD1 mutants exhibit molecular alterations indicative of a recruitment of ER's signaling machinery. We demonstrate by biochemical and morphological methods that mutant SOD1 accumulates inside the ER, where it forms insoluble high molecular weight species and interacts with the ER chaperone immunoglobulin-binding protein. These alterations are age-and regionspecific, because they develop over the course of the disease and occur in the affected spinal cord but not in the nonaffected cerebellum in transgenic mutant SOD1 mice. Our results suggest a toxic mechanism for mutant SOD1 by which this ubiquitously expressed pathogenic protein could affect motor neuron survival and contribute to the selective motor neuronal degeneration in ALS.neurodegeneration ͉ protein misfolding A LS is the most common adult-onset paralytic disease characterized by a loss of motor neurons in the cerebral cortex, brainstem, and spinal cord. Insights into the neurodegenerative mechanisms followed the discovery that dominant mutations in the gene for superoxide dismutase-1 (SOD1) cause familial ALS. Overexpression of SOD1 mutants in rodents recapitulates ALS clinical and pathological hallmarks through a toxic gain of function (1). Many mutations in SOD1 decrease its stability and increase its unfolding rates and propensity to aggregate (2). High molecular weight complexes of SOD1 are observed in mammalian cells and spinal cords of transgenic mice expressing this mutant protein (3). In these animals, intracellular ubiquitin-positive proteinaceous inclusions are also often seen in spinal cord motor neurons and, in some cases, in neighboring astrocytes (3-5). These findings posit that accumulation of misfolded mutant SOD1 could contribute to the demise of motor neurons.Endoplasmic reticulum (ER) stress signaling, otherwise known as the unfolded protein response (UPR), is triggered by an increased load of misfolded proteins in the organelle (6). Herein, we show that transgenic mice expressing mutant SOD1 exhibit age-and region-specific molecular alterations indicative of a broad recruitment of ER signaling pathways, including caspase-12, a prototypical ER cell death effector (7). We also show that mutant SOD1, and to a lesser extent wild-type SOD1 (SOD1 WT ), do accumulate in the ER. Within this organelle, mutant, but not SOD1 WT , forms high molecular weight species and interacts with the ER chaperone immunoglobulin-binding protein (BiP), which is a key component of the ER misfolded protein recognition machinery (6). The preferential accumulation of mutant SOD1 in the ER in the spinal cord cells and the ensuing stress response may represent novel aspects of motor neuron degeneration in this ALS model.
The establishment of human induced pluripotent stem cells (hiPSCs) has enabled the production of in vitro, patient-specific cell models of human disease. In vitro recreation of disease pathology from patient-derived hiPSCs depends on efficient differentiation protocols producing relevant adult cell types. However, myogenic differentiation of hiPSCs has faced obstacles, namely, low efficiency and/or poor reproducibility. Here, we report the rapid, efficient, and reproducible differentiation of hiPSCs into mature myocytes. We demonstrated that inducible expression of myogenic differentiation1 (MYOD1) in immature hiPSCs for at least 5 days drives cells along the myogenic lineage, with efficiencies reaching 70–90%. Myogenic differentiation driven by MYOD1 occurred even in immature, almost completely undifferentiated hiPSCs, without mesodermal transition. Myocytes induced in this manner reach maturity within 2 weeks of differentiation as assessed by marker gene expression and functional properties, including in vitro and in vivo cell fusion and twitching in response to electrical stimulation. Miyoshi Myopathy (MM) is a congenital distal myopathy caused by defective muscle membrane repair due to mutations in DYSFERLIN. Using our induced differentiation technique, we successfully recreated the pathological condition of MM in vitro, demonstrating defective membrane repair in hiPSC-derived myotubes from an MM patient and phenotypic rescue by expression of full-length DYSFERLIN (DYSF). These findings not only facilitate the pathological investigation of MM, but could potentially be applied in modeling of other human muscular diseases by using patient-derived hiPSCs.
Our cell-based assay is useful for anti-cN1A autoantibodies detection. Patients with anti-cN1A autoantibodies demonstrated unique clinicopathological features. In vitro and in vivo passive immunization model results suggest that anti-cN1A autoantibodies may affect protein degradation in myofibers. Ann Neurol 2017;81:512-525.
Background: To assess the efficacy, safety, and tolerability of bimagrumab (fully human monoclonal antibody) in participants with inclusion body myositis (IBM). Methods: This multicentre, double-blind, placebo-controlled study (RESILIENT; ClinicalTrials.gov, number NCT01925209) was conducted between September 26, 2013 and January 06, 2016 at academic clinical sites in Europe, the USA, Australia, and Japan. Eligible participants (aged 36-85 years [inclusive]; modified 2010 MRC criteria) were randomly assigned (1:1:1:1) using blocked randomisation schedule (block size=4) to receive intravenous infusions of bimagrumab 10, 3, 1 mg/kg, or placebo every 4 weeks for at least 48 weeks. All study participants, sponsor, investigators, site personnel, and those performing assessments were masked to treatment assignment. 6-minute walking distance (6MWD; primary outcome measure) was assessed at Week 52 in the primary analysis population. A multivariate normal repeated measures model was used to analyse data on 6MWD. Safety was assessed by recording adverse events (AEs), electrocardiography, echocardiography, hematology, urinalysis, and blood chemistry.
BACKGROUND AND PURPOSE:Quantitative susceptibility mapping is useful for assessing iron deposition in the substantia nigra of patients with Parkinson disease. We aimed to determine whether quantitative susceptibility mapping is useful for assessing the lateral asymmetry and spatial difference in iron deposits in the substantia nigra of patients with Parkinson disease.
Cylindromatosis (CYLD) is a tumor suppressor gene that is mutated in familial cylindromatosis, a rare autosomal dominant disorder associated with numerous benign skin adnexal tumors. CYLD is now known to regulate various signaling pathways, including transforming growth factor-β signaling, Wnt/β-catenin signaling, and NF-κB signaling by deubiquitinating upstream regulatory factors. Downregulation of CYLD has been reported in several malignancies; however, the clinical significance of CYLD expression in many malignancies, including breast cancer, remains to be elucidated. This study investigated the clinical significance of CYLD in breast cancer and its roles in tumor progression. We evaluated CYLD expression in matched normal breast tissue samples and tumor breast tissue samples from 26 patients with breast cancer and in a series of breast cancer cell lines. In addition, by means of immunohistochemistry, we investigated CYLD protein expression and its clinical significance in 244 breast cancer cases. We also analyzed the effects of CYLD repression or overexpression on breast cancer cell viability, cell migration, and NF-κB activity with or without receptor activator of NF-κB ligand (RANKL) stimulation. Breast cancer tissues demonstrated significantly reduced CYLD mRNA expression compared with normal breast tissues. Downregulation of CYLD promoted cell survival and migratory activities through NF-κB activation, whereas CYLD overexpression inhibited those activities in MDA-MB-231 cells. As an important finding, CYLD overexpression also inhibited RANKL-induced NF-κB activation. Our immunohistochemical analysis revealed that reduced CYLD protein expression was significantly correlated with estrogen receptor negativity, high Ki-67 index, high nuclear grade, decreased disease-free survival, and reduced breast cancer-specific survival in primary breast cancer. Moreover, reduced CYLD expression was an independent factor for poor prognosis in breast cancer. CYLD downregulation may promote breast cancer metastasis via NF-κB activation, including RANKL signaling.
Amyotrophic lateral sclerosis (ALS) is the most common adult-onset motor neuron disease. It is characterized by neuronal loss and degeneration of the upper motor neurons (UMNs) and lower motor neurons (LMNs), and is usually fatal due to respiratory failure within 3–5 years of onset. Although approximately 5–10 % of patients with ALS have an inherited form of the disease, the distinction between hereditary and apparently sporadic ALS (SALS) seems to be artificial. Thus, genetic factors play a role in all types of ALS, to a greater or lesser extent. During the decade of upheaval, the evolution of molecular genetics technology has rapidly advanced our genetic knowledge about the causes of ALS, and the relationship between the genetic subtypes and clinical phenotype. In this review, we will focus on the possible genotype-phenotype correlation in hereditary ALS. Uncovering the identity of the genetic factors in ALS will not only improve the accuracy of ALS diagnosis, but may also provide new approaches for preventing and treating the disease.Electronic supplementary materialThe online version of this article (doi:10.1186/s40035-015-0036-y) contains supplementary material, which is available to authorized users.
Background and purposeOxidative stress has been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). Edaravone, a free radical scavenger, was approved as a therapeutic drug for ALS in 2015 in Japan. A phase 3 clinical trial demonstrated a smaller decline in ALS functional scale scores compared with placebo. However, the long-term effects of edaravone on ALS patients remain unclear. This study aimed to retrospectively investigate the long-term effects of edaravone on the survival of ALS patients.MethodsWe retrospectively analyzed 27 consecutive patients with ALS who were treated with edaravone and 30 consecutive ALS patients who were not treated with edaravone between 2010 and 2016.ResultsThe differences of ALSFRS-R scores from baseline to 6 months was significantly reduced in the edaravone group, compared to the control group. The changes in serum creatinine, as a possible marker of ALS severity, from baseline to 6 and 12 months were significantly improved in the edaravone group, compared to the control group. The survival rate was significantly improved in the edaravone group compared with control patients.ConclusionOur retrospective single-center analysis suggests slower progression and better prognosis of ALS patients with edaravone treatment. Further investigation, including prospective multicenter analysis, is warranted to confirm the usefulness of edaravone for a better prognosis of ALS.
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