Electrophysiological biomarkers in spinal muscular atrophy: proof of concept
نویسندگان
چکیده
OBJECTIVE Preclinical therapies that restore survival motor neuron (SMN) protein levels can dramatically extend survival in spinal muscular atrophy (SMA) mouse models. Biomarkers are needed to effectively translate these promising therapies to clinical trials. Our objective was to investigate electrophysiological biomarkers of compound muscle action potential (CMAP), motor unit number estimation (MUNE) and electromyography (EMG) using an SMA mouse model. METHODS Sciatic CMAP, MUNE, and EMG were obtained in SMNΔ7 mice at ages 3-13 days and at 21 days in mice with SMN selectively reduced in motor neurons (ChATCre ). To investigate these measures as biomarkers of treatment response, measurements were obtained in SMNΔ7 mice treated with antisense oligonucleotide (ASO) or gene therapy. RESULTS CMAP was significantly reduced in SMNΔ7 mice at days 6-13 (p<0.01), and MUNE was reduced at days 7-13 (p<0.01). Fibrillations were present on EMG in SMNΔ7 mice but not controls (p=0.02). Similar findings were seen at 21 days in ChATCre mice. MUNE in ASO-treated SMNΔ7 mice were similar to controls at day 12 and 30. CMAP reduction persisted in ASO-treated SMNΔ7 mice at day 12 but was corrected at day 30. Similarly, CMAP and MUNE responses were corrected with gene therapy to restore SMN. INTERPRETATION These studies confirm features of preserved neuromuscular function in the early postnatal period and subsequent motor unit loss in SMNΔ7 mice. SMN restoring therapies result in preserved MUNE and gradual repair of CMAP responses. This provides preclinical evidence for the utilization of CMAP and MUNE as biomarkers in future SMA clinical trials.
منابع مشابه
Drawing Word co-occurrence map of Spinal Muscular Atrophy disease
Introduction: The purpose of this article is to evaluate the status of articles in the field of Spinal Muscular Atrophy According to the Scientometrics indices Word co-occurrence map of this field . Methods: The present study is an applied one with a quantitative approach and a descriptive approach. It has been done using scientometrics and the co-occurrence words analysis technique. Document...
متن کاملSpinal Muscular Atrophy: A Short Review Article
Spinal muscular atrophy (SMA) is a genetic disorder which affect nervous system and is characterized with progressive distal motor neuron weakness. The survival motor neuron (SMN) protein level reduces in patients with SMA. Two different genes code survival motor neuron protein in human genome. Skeletal and intercostal muscles denervation lead to weakness, hypotony, hyporeflexia, respiratory fa...
متن کاملSpinal muscular atrophy in childhood.
Diagnosis and classification of spinal muscular atrophy (SMA) in childhood are based on clinical, electrophysiological, and histological studies. The concept of maturational arrest of motoneurons and their targets (muscle cells in SMA type I) is documented by ultrastructural and immunohistochemical data. The prolongated or markedly delayed process of muscle cell and motoneuron elimination by ap...
متن کاملAssessment of Preimplantation Genetic Diagnosis (PGD) for Childhood-onset Spinal Muscular Atrophy (SMA) Using Duplex Fluorescent PCR
متن کامل
Juvenile proximal spinal muscular atrophy with early hypertrophy of calves.
The clinical, electrophysiological, histological and ultrastructural features of a patient with chronic spinal muscular atrophy of adolescent onset associated with hypertrophied calf-muscle are described. This recently recognised entity must be distinguished from other types of spinal muscular atrophy.
متن کامل