Voltage-Dependent Sodium Channels in Spinal Cord Motor Neurons Display Rapid Recovery From Fast Inactivation in a Mouse Model of Amyotrophic Lateral Sclerosis

2006 ◽  
Vol 96 (6) ◽  
pp. 3314-3322 ◽  
Author(s):  
Cristina Zona ◽  
Massimo Pieri ◽  
Irene Carunchio

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by a substantial loss of motor neurons in the spinal cord, brain stem, and motor cortex. Previous evidence showed that in a mouse model of a familial form of ALS expressing high levels of the human mutated protein Cu,Zn superoxide dismutase (Gly93→Ala, G93A), the firing properties of single motor neurons are altered to induce neuronal hyperexcitability. To determine whether the functionality of the macroscopic voltage-dependent Na+ currents is modified in G93A motor neurons, in the present work their physiological properties were examined. The voltage-dependent sodium channels were studied in dissociated motor neurons in culture from nontransgenic mice (Control), from transgenic mice expressing high levels of the human wild-type protein [superoxide dismutase 1 (SOD1)], and from G93A mice, using the whole cell configuration of the patch-clamp recording technique. The voltage dependency of activation and of steady-state inactivation, the kinetics of fast inactivation and slow inactivation of the voltage-dependent Na+ channels were not modified in the mutated mice. Conversely, the recovery from fast inactivation was significantly faster in G93A motor neurons than that in Control and SOD1. The recovery from fast inactivation was still significantly faster in G93A motor neurons exposed for different times (3–48 h) and concentrations (5–500 μM) to edaravone, a free-radical scavenger. Clarification of the importance of these changes in membrane ion channel functionality may have diagnostic and therapeutic implications in the pathogenesis of ALS.

2008 ◽  
Vol 36 (6) ◽  
pp. 1322-1328 ◽  
Author(s):  
Willianne I.M. Vonk ◽  
Leo W.J. Klomp

ALS (amyotrophic lateral sclerosis) is a devastating progressive neurodegenerative disorder resulting in selective degeneration of motor neurons in brain and spinal cord and muscle atrophy. In approx. 2% of all cases, the disease is caused by a mutation in the Cu,Zn-superoxide dismutase (SOD1) gene. The transition metals zinc and copper regulate SOD1 protein stability and activity, and disbalance of the homoeostasis of these metals has therefore been implicated in the pathogenesis of ALS. Recent data strengthen the hypothesis that these transition metals are excellent potential targets to develop an effective therapy for ALS.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yasuhiro Kosuge ◽  
Erina Kaneko ◽  
Hiroshi Nango ◽  
Hiroko Miyagishi ◽  
Kumiko Ishige ◽  
...  

Amyotrophic lateral sclerosis (ALS) is a late-onset neurodegenerative disorder characterized by progressive paralysis resulting from the death of upper and lower motor neurons. There is currently no effective pharmacological treatment for ALS, and the two approved drugs riluzole and edaravone have limited effects on the symptoms and only slightly prolong the life of patients. Therefore, the development of effective therapeutic strategies is of paramount importance. In this study, we investigated whether Miyako Island Bidens pilosa (MBP) can alleviate the neurological deterioration observed in a superoxide dismutase-1 G93A mutant transgenic mouse (G93A mouse) model of ALS. We orally administered 2 g/kg/day of MBP to G93A mice at the onset of symptoms of neurodegeneration (15 weeks old) until death. Treatment with MBP markedly prolonged the life of ALS model mice by approximately 20 days compared to that of vehicle-treated ALS model mice and significantly improved motor performance. MBP treatment prevented the reduction in SMI32 expression, a neuronal marker protein, and attenuated astrocyte (detected by GFAP) and microglia (detected by Iba-1) activation in the spinal cord of G93A mice at the end stage of the disease (18 weeks old). Our results indicate that MBP administered after the onset of ALS symptoms suppressed the inflammatory activation of microglia and astrocytes in the spinal cord of the G93A ALS model mice, thus improving their quality of life. MBP may be a potential therapeutic agent for ALS.


2019 ◽  
Vol 28 (19) ◽  
pp. 3175-3187
Author(s):  
Binukumar BK ◽  
Susan Skuntz ◽  
Michaela Prochazkova ◽  
Sashi Kesavapany ◽  
Niranjana D Amin ◽  
...  

Abstract Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that affects motor nerve cells in the brain and the spinal cord. Etiological mechanisms underlying the disease remain poorly understood; recent studies suggest that deregulation of p25/Cyclin-dependent kinase 5 (Cdk5) activity leads to the hyperphosphorylation of Tau and neurofilament (NF) proteins in ALS transgenic mouse model (SOD1G37R). A Cdk5 involvement in motor neuron degeneration is supported by analysis of three SOD1G37R mouse lines exhibiting perikaryal inclusions of NF proteins and hyperphosphorylation of Tau. Here, we tested the hypothesis that inhibition of Cdk5/p25 hyperactivation in vivo is a neuroprotective factor during ALS pathogenesis by crossing the new transgenic mouse line that overexpresses Cdk5 inhibitory peptide (CIP) in motor neurons with the SOD1G37R, ALS mouse model (TriTg mouse line). The overexpression of CIP in the motor neurons significantly improves motor deficits, extends survival and delays pathology in brain and spinal cord of TriTg mice. In addition, overexpression of CIP in motor neurons significantly delays neuroinflammatory responses in TriTg mouse. Taken together, these data suggest that CIP may serve as a novel therapeutic agent for the treatment of neurodegenerative diseases.


2015 ◽  
Vol 35 (14) ◽  
pp. 2385-2399 ◽  
Author(s):  
Nadine Bakkar ◽  
Arianna Kousari ◽  
Tina Kovalik ◽  
Yang Li ◽  
Robert Bowser

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the selective loss of motor neurons. Various factors contribute to the disease, including RNA binding protein dysregulation and oxidative stress, but their exact role in pathogenic mechanisms remains unclear. We have recently linked another RNA binding protein, RBM45, to ALS via increased levels of protein in the cerebrospinal fluid of ALS patients and its localization to cytoplasmic inclusions in ALS motor neurons. Here we show RBM45 nuclear exit in ALS spinal cord motor neurons compared to controls, a phenotype recapitulatedin vitroin motor neurons treated with oxidative stressors. We find that RBM45 binds and stabilizes KEAP1, the inhibitor of the antioxidant response transcription factor NRF2. ALS lumbar spinal cord lysates similarly show increased cytoplasmic binding of KEAP1 and RBM45. Binding of RBM45 to KEAP1 impedes the protective antioxidant response, thus contributing to oxidative stress-induced cellular toxicity. Our findings thus describe a novel link between a mislocalized RNA binding protein implicated in ALS (RBM45) and dysregulation of the neuroprotective antioxidant response seen in the disease.


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