hNT neurons delay onset of motor deficits in a model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a degenerative motor neuron disease that manifests as a progressive muscular weakness leading to paralysis and death. Because of the diffuse nature of the motor neuron death, this disease is not considered a good candidate for treatment through neural transplantation. The purpose of this study was to show that transplantation of human neuron-like cells (hNT neurons) into the spinal cord of a transgenic ALS mouse model would improve motor deficits. The hNT neurons were transplanted bilaterally into L4-L5 spinal cord of the transgenic mice ( approximately 8 weeks of age), and the animals were evaluated on health and behavioral measures. The animals were perfused, and immunohistochemistry was performed to identify the transplanted cells. Transplantation of the hNT neurons into the spinal cord delayed the onset of motor behavioral symptoms. This was the first demonstration that even localized transplantation of neural cells directly into the parenchyma could improve motor function in an ALS model. Further study is needed to delineate the mechanism underlying these effects. This therapeutic approach has the potential to restore neural transmission, thereby improving quality of life for the ALS patient and possibly extend life expectancy.     

内质网应激因子ATF6在hSOD1~(G93A)转基因小鼠脊髓中的表达

目的应用目前国际公认的肌萎缩侧索硬化(ALS)发病机制及临床前药物研究的动物模型hSOD1~(G93A)转基因小鼠,初步研究hSOD1~(G93A)小鼠脊髓中是否存在内质网应激中活性转录激活因子(ATF6)信号通路的激活,进而探究内质网应激在ALS发病机制中的作用。方法①hSOD1~(G93A)转基因小鼠及其同窝对照组小鼠的获得;②应用免疫组织化学方法观察转基因小鼠组和对照组显示脊髓前角运动神经元ATF6阳性细胞数量。结果症状早期和终末期转基因小鼠(分别为105~115d和120~130d),较对照组和无症状组转基因小鼠(60d)ATF6进入细胞核的运动神经元数量明显增多,差异有统计学意义(P0.05);症状早期和终末期相比较差异无统计学意义(P0.05);症状早期和终末期的一些细胞形态发生改变,出现皱缩,终末期运动神经元的数目减少。结论在无症状组时没有发现内质网应激因子ATF6的改变,但在疾病症状早期出现明显ATF6的改变,并随着疾病的进展而加重,说明内质网应激参与了ALS的发病,同时终末期脊髓前角运动神经元数量大幅减少。     

Ifenprodil对肌萎缩侧索硬化离体模型中运动神经元的保护作用

目的 探讨Ifenprodil对苏-羟天冬氨酸(THA)诱导的肌萎缩侧索硬化(ALS)离体模型中运动神经元的保护作用.方法 在离体培养的脑组织片中加入THA造成慢性谷氨酸损伤,模拟肌萎缩侧索硬化的特征性病理改变.将脑片分为6组:(1)对照组,不添加THA; (2)THA损伤组,细胞换液时加入100 μmol/L THA,持续1周;(3)不同剂量Ifenprodil组(分别在THA损伤基础上添加0.1、1、10、100 μmol/L Ifenprodil);每组6个培养皿.Ifenprodil 于THA损伤前2h加入到各组脑片中.根据PI染色的荧光亮度测定Ifenprodil保护作用的最佳浓度.在损伤的不同时间点用丙二醛(MDA)试剂盒测定培养体系中MDA的含量,Western blotting测定运动皮层中半胱氨酸天冬氨酸酶-3(caspase-3)蛋白表达量.结果 PI染色显示10 μmol/L Ifenprodil对运动神经元有明显保护作用.THA损伤后,培养体系中MDA含量明显增加,运动皮层中caspase-3活化亚基(相对分子量为17 000)表达量增高,与其他组别比较差异有统计学意义(P＜0.05).10μmol/L Ifenprodil能有效阻止MDA和活化caspase-3的增加.结论 Ifenprodil能够通过减轻运动神经元的氧化应激反应,抑制caspase-3活化,进而有效保护ALS离体模型中运动神经元的损伤.     

家族性肌萎缩侧索硬化动物模型脊髓侧角神经元特征

目的探讨脊髓侧角神经元在SOD1G93A转基因鼠发病过程中的变化特征。方法利用甲苯胺蓝染色及免疫组化的方法观察SOD1G93A转基因小鼠不同病变时期上、中、下胸髓侧角神经元的数量变化特征。结果甲苯胺蓝染色法定量研究发现不同时期SOD1G93A转基因小鼠上胸髓、下胸髓水平,症状前期和发病期神经元计数较终末期均有显著性差别(P<0.05);与对照组相比,终末期胸髓各段侧角神经元计数明显减少且有统计学意义;免疫组化发现SOD1G93A转基因小鼠上胸髓、中胸髓水平不同时期相比,症状前期和发病期乙酰胆碱酯酶(AchE)阳性神经元计数较终末期均有显著性差别(P<0.05);与对照组相比,发病期上胸髓及终末期中、下胸髓水平侧角AchE阳性神经元数量减少具有统计学意义;结论在SOD1G93A转基因鼠发病过程中,存在脊髓侧角神经元丢失,尤其是在疾病的终末期,上、中、下胸髓节段间无明显差异。     

Characterizations of heterotopic neurons in the spinal cord of amyotrophic lateral sclerosis patients

This report concerns a comparative immunocytochemical, ultrastructural and morphometric investigation on heterotopic neurons in the white matter of the spinal cords of 19 patients with amyotrophic lateral sclerosis (ALS) and 18 age-matched neurologically normal individuals. The study revealed that the heterotopic neurons were scattered in the white matter, often adjacent to gray matter, that they immunoreacted with the antibody to synaptophysin, and that there were synaptic apparatuses on the surface of their somata and their neuronal processes. Bunina bodies and ubiquitin-positive inclusions such as Lewy body-like inclusions and skein-like inclusions, characteristic of anterior horn neurons of ALS, were present in the cytoplasm of the patients’ heterotopic neurons in the anterior or lateral column of the white matter. These findings suggest that heterotopic neurons in the anterior or lateral column have the characteristics of alpha motor neurons. The average number of heterotopic neurons observed in ALS patients was generally less than in normal subjects. This reduction was correlated with the severity of neuronal loss. The heterotopic neurons in ALS were less susceptible to the degenerative process as compared with spinal cord anterior horn cells. We assume that in this disease the heterotopic neurons may be degenerated and their number diminished after or concomitantly with the depletion of anterior horn neurons. Received: 18 August 1997 / Revised, accepted: 20 October 1997     

Intravenous immunoglobulin therapy in amyotrophic lateral sclerosis

Seven consecutive patients with amyotrophic lateral sclerosis (ALS) were treated with intravenous immunoglobulins (IVIg; 0.4 g/kg per day for 5 consecutive days followed by monthly 2-day infusions at the same daily dosage) continued with oral cyclophosphamide (1–2 mg/kg per day), for 4–13 months (mean 8.1). Response to treatment was assessed by means of the Medical Research Council (MRC) rating scale for muscle strength on 40 muscles (10 per limb), a clinical scale for bulbar function and a modified Rankin disability scale. All patients continued to deteriorate during treatment on as regards both their MRC score and either their bulbar or Rankin score or both. The progression of the disease during treatment, expressed as the monthly variation in MRC score (mean=−2.71; SD=1.36), was no slower than that estimated before therapy (mean=−1.81; SD=0.93). Even if the results of this small, uncontrolled study do not permit the exclusion of an effect of IVIg on the progression of ALS, they also do not provide any evidence that this expensive form of therapy consistently slows the course of the disease.     

甲基汞引发的大鼠脊髓前角大型运动神经元的脱落

目的研究有机汞中毒大鼠脊髓前角的病理学改变。方法使用每日１０ｍｇ／ｋｇ甲基汞，给成熟大鼠连续灌胃１０日，观察其脊髓、前根及肌肉的病理学所见。结果首次投药１４日起，脊髓前角大型运动神经元胞质内出现空胞及尼氏小体脱失；在１６日观察到噬节现象；到１８日，前角大型运动神经元高度脱落，而中、小型神经元则无明显减少。使用醋酸银金属自显影技术亦检测到脊髓前角大型运动神经元有汞的特异性沉积。结论以往报道的汞中毒性类肌萎缩侧索硬化综合征的主要病理学基础为脊髓前角运动神经元的变性、脱落，本实验动物模型可以作为研究运动神经元疾病病理生理学改变的有用模型。     

Myostatin inhibition slows muscle atrophy in rodent models of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease leading to motor neuron cell death, but recent studies suggest that non-neuronal cells may contribute to the pathological mechanisms involved. Myostatin is a negative regulator of muscle growth whose function can be inhibited using neutralizing antibodies. In this study, we used transgenic mouse and rat models of ALS to test whether treatment with anti-myostatin antibody slows muscle atrophy, motor neuron loss, or disease onset and progression. Significant increases in muscle mass and strength were observed in myostatin-antibody-treated SOD1(G93A) mice and rats prior to disease onset and during early-stage disease. By late stage disease, only diaphragm muscle remained significantly different in treated animals in comparison to untreated controls. Myostatin inhibition did not delay disease onset nor extend survival in either the SOD1(G93A) mouse or rat. Together, these results indicate that inhibition of myostatin does not protect against the onset and progression of motor neuron degenerative disease. However, the preservation of skeletal muscle during early-stage disease and improved diaphragm morphology and function maintained through late stage disease suggest that anti-myostatin therapy may promote some improved muscle function in ALS.     

Excitatory amino acid transporter 1 and 2 immunoreactivity in the spinal cord in amyotrophic lateral sclerosis

The spinal cord of 20 patients with amyotrophic lateral sclerosis (ALS) and 5 patients with lower motor neuron disease (LMND) were investigated immunohistochemically using anti-human excitatory amino acid transporter 1 (EAAT1) and EAAT2 antibodies which are the astrocytic transporters. The purpose of the study was to examine relationships between EAAT1 and EAAT2 immunoreactivity and degeneration of anterior horn neurons. Specimens from 20 patients without any neurological disease served as controls. In controls, spinal cord gray matter was densely immunostained by antibodies, whereas the white matter was generally not immunostained. In motor neuron disease (MND) patients, EAAT1 immunoreactivity was relatively well preserved in the gray matter despite neuronal loss of anterior horn cells. On the other hand, EAAT2 immunoreactivity in anterior horns correlated with the degree of neuronal loss of anterior horn cells: in the patients with mild neuronal depletion, anterior horns were densely immunostained by the antibody, whereas in the patients with severe neuronal loss, EAAT2 expression was markedly reduced. Degenerated anterior horn cells frequently showed a much denser EAAT1 and EAAT2 immunoreactivity around the surface of the neurons and their neuronal processes than that observed in normal-appearing neurons. There was no difference in the expression of EAAT1 and EAAT2 immunoreactivity between LMND and ALS patients. These findings suggest that in the early stage of degeneration of anterior horn cells, EAAT1 and EAAT2 immunoreactivity is preserved in the astrocytic foot directly attached to normal-appearing neurons, whereas levels of EAAT1 and EAAT2 protein rather increase in the astrocytic foot directly attached to degenerated anterior horn neurons; the latter effect most probably reduces the elevated glutamate level, compensates for the reduced function of astroglial glutamate transporters, or represents a condensation of EAAT1 and EAAT2 immunoreactivity secondary to loss of neurites and greater condensation of astrocytic processes. Thus, we demonstrate a difference in EAAT1 and EAAT2 immunoreactivity in different stages of progression in ALS, as a feature of the pathomechanism of this disease. Received: 8 September 1999 / Revised, accepted: 28 October 1999     

Multi-dimensional electrical impedance myography of the tongue as a potential biomarker for amyotrophic lateral sclerosis

ObjectiveIn amyotrophic lateral sclerosis (ALS) bulbar disease biomarkers are lacking. We evaluated a novel tongue electrical impedance myography (EIM) system, utilising both 2D and 3D electrode configurations for detection of tongue pathology.MethodsLongitudinal multi-frequency phase angle spectra were recorded from 41 patients with ALS (baseline, 3 and 6 months) and 30 healthy volunteers (baseline and 6 months). ALS functional rating scale-revised (ALSFRS-R) data and quantitative tongue strength measurements were collected. EIM data were analysed for reliability (intra-class correlation coefficient; ICC) and differences between patients and volunteers ascertained using both univariate (Mann-Whitney U test) and multivariate techniques (feature selection and L2 norm).ResultsThe device produced highly reliable data (pooled ICC: 0.836). Significant EIM differences were apparent between ALS patients and healthy volunteers (P < 0.001). EIM data demonstrated a significant relationship to tongue strength and bulbar ALSFRS-R scores (P < 0.015). The EIM recordings revealed a group level longitudinal change over 6 months and consistently identified patients in whom symptoms or tongue strength changed.ConclusionsThe novel EIM tongue system produces reliable data and can differentiate between healthy muscle and ALS-related disease.SignificanceTongue EIM utilising multiple frequencies and electrode configurations has potential as a bulbar disease biomarker in ALS.     

Motor unit firing in amyotrophic lateral sclerosis and other upper and lower motor neurone disorders

Objective

Motor unit recruitment order and firing rate was investigated in healthy subjects, and in small numbers of patients 50 years ago. We aimed to investigate firing rate in different disorders, testing the same target muscle with normal strength, to evaluate possible application in diagnosing upper motor neuron (UMN) lesion.

Methods

We studied motor unit firing in the tibialis anterior muscle in six groups of subjects; normal subjects (n = 45), patients with amyotrophic lateral sclerosis (ALS) (n = 36), primary lateral sclerosis (PLS) (n = 21), progressive muscular atrophy (PMA) (n = 14), various upper motor neurone lesions (n = 16) and polyneuropathy (n = 42). In all these subjects the tibialis anterior muscle was of normal strength. Motor units were recruited during slight contraction in order to study 2–5 motor units at each recording site, using a standard concentric needle electrode, so that 20–22 motor units were recorded in each muscle. We analysed the coefficient of variation (CV) for amplitude, area, duration and firing rate in these motor units, and the correlation between motor unit potential size and recruitment order.

Results

The mean MU firing rate in this task was similar in each group. No recruitment order was disclosed within the limits of the study task. The CV of firing rate was decreased in UMN and PLS groups. ALS patients with marked spasticity showed a lower CV of motor unit firing rate. The CV of amplitude, area and duration was similar between groups.

Conclusions

These results in tibialis anterior indicate that physiological modulation of lower motor neuron (LMN) firing rate is decreased in patients with lower limb spasticity. The variability of MU discharges tends to be greater in diseases affecting the LMN.

Significance

These results suggest that, notwithstanding the simplicity of the task we have used, the physiological variability of motor unit firing may be a useful variable in assessing UMN involvement in motor system disorders.     

Mercury in human spinal motor neurons

Inorganic mercury has been proposed as a neurotoxin that could cause sporadic motor neuron disease (SMND). We were therefore interested to see if mercury could be detected in the upper and lower motor neurons of SMND patients, and if mercury accumulated within motor neurons during life. Paraffin sections of formalin-fixed spinal cord (22 control adults, 20 SMND adults, 25 infants) and frontal primary motor cortex (9 control adults, 18 SMND adults, 20 infants) were stained with silver nitrate autometallography to detect ionic mercury. Mercury was found in the spinal motor neurons of 36% of adult control cases and 45% of adult SMND cases, with no significant difference between groups. No mercury was seen in infant spinal motor neurons, or in any adult or infant corticomotoneurons. In conclusion, many humans appear to accumulate mercury in their spinal motor neurons by the time they are adults, but mercury does not appear to play a major role in the loss of upper or lower motor neurons in SMND. Received: 27 December 1997 / Revised, accepted: 12 May 1998     

Effect of rosmarinic acid in motor dysfunction and life span in a mouse model of familial amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a late‐onset progressive neurodegenerative disease affecting motor neurons. About 2% of patients with the disease are associated with mutations in the gene encoding Cu/Zn superoxide dismutase (SOD1). The purpose of this study is to assess the effect of rosemary extract and its major constituents, rosmarinic acid (RA) and carnosic acid (CA), in human SOD1 G93A transgenic mice, which are well‐established mouse models for ALS. The present study demonstrates that intraperitoneal administration of rosemary extract or RA from the presymptomatic stage significantly delayed motor dysfunction in paw grip endurance tests, attenuated the degeneration of motor neurons, and extended the life span of ALS model mice. In addition, RA administration significantly improved the clinical score and suppressed body weight loss compared with a vehicle‐treated group. In conclusion, this study provides the first report that rosemary extract and, especially, RA have preventive effects in the mouse model of ALS. © 2009 Wiley‐Liss, Inc.     

Impaired hypoxic sensor Siah‐1, PHD3, and FIH system in spinal motor neurons of an amyotrophic lateral sclerosis mouse model

We recently reported spinal blood flow–metabolism uncoupling in the Cu/Zn‐superoxide dismutase 1 (SOD1)‐transgenic (Tg) mouse model of amyotrophic lateral sclerosis (ALS), suggesting relative hypoxia in the spinal cord. However, the hypoxic stress sensor pathway in ALS has not been well studied. In the present work, we examined the temporal and spatial changes of hypoxic stress sensor proteins (Siah‐1, PHD3, and FIH) following motor neuron (MN) degeneration in the spinal cord of normoxic ALS mice. The expression of Siah‐1 and PHD3 proteins progressively increased in the surrounding glial cells of presymptomatic Tg mice (10 weeks, 10 weeks) compared with the large MN of the anterior horn. In contrast, a significant reduction in Siah‐1 and PHD3 protein expression was evident in end‐stage ALS mice (18 weeks, 18 weeks). Double‐immunofluorescence analysis revealed PHD3 plus Siah‐1 double‐positive cells in the surrounding glia of symptomatic Tg mice (14–18 weeks), with no change in the large MNs. In contrast, FIH protein expression decreased in the surrounding glial cells of Tg mice at end‐stage ALS (18 weeks). The present study suggests a partial loss in the neuroprotective response of spinal MNs in ALS results from a relative hypoxia through the Siah‐1, PHD3, and FIH system under normoxic conditions. This response could be an important mechanism of neurodegeneration in ALS. © 2012 Wiley Periodicals, Inc.     

Peroxisome proliferator-activated receptor-gamma agonist extends survival in transgenic mouse model of amyotrophic lateral sclerosis

Accumulating evidence suggests that inflammation plays a major role in the pathogenesis of motoneuron death in amyotrophic lateral sclerosis (ALS) both in humans and transgenic mouse models. Peroxisome proliferator-activated receptors (PPARs) are involved in the inflammatory process. Agonists of PPAR-alpha, -gamma, and -delta show anti-inflammatory effects both in vitro and in vivo. We investigated the therapeutic effect of pioglitazone, a peroxisome proliferator-activated receptor-gamma (PPAR-gamma) agonist, in the G93A SOD1 transgenic mouse model of ALS. Orally administered pioglitazone improved motor performance, delayed weight loss, attenuated motor neuron loss, and extended survival of G93A mice as compared to the untreated control littermate group. Pioglitazone treatment extended survival by 13%, and it reduced gliosis as assessed by immunohistochemical staining for CD-40 and GFAP. Pioglitazone also reduced iNOS, NFkappa-B, and 3-nitrotyrosine immunoreactivity in the spinal cords of G93A transgenic mice. These results suggest that pioglitazone may have therapeutic potential for human ALS.     

Ultrastructural study of chromatolytic neurons in an adult-onset sporadic case of amyotrophic lateral sclerosis

Summary Ultrastructural features of chromatolytic neurons observed in a sporadic case with amyotrophic lateral sclerosis (ALS) are reported. A 70-year-old woman died of weakness and atrophy of the four limbs, bulbar and facial muscles, and hyperreflexia, of 3 1/2 years' duration. Neuronal loss was marked in the anterior horn of the spinal cord, with degeneration of the pyramidal tracts. Most of the remaining neurons showed chromatolysis. Some of the chromatolytic neurons contained faintly eosinophilic inclusions with a halo. Few spheroids were observed. Hypoglossal nuclei, nucleus ambiguus, motor nuclei of N. VII and N.V were well populated, but contained several chromatolytic neurons. Ultrastructurally, the chromatolytic neurons contained aggregates of fibrils thicker than the 10-nm neurofilaments. These fibrils were arranged randomly, and were closely associated with granular materials as well as rough endoplasmic reticulum. Neurofilamentous accumulations reported to be common in sporadic ALS were rare in this case. No Bunina body was observed.Supported in part by a research grant from the Japan Association of Life insurance     

Persistent inward currents in spinal motoneurons: Important for normal function but potentially harmful after spinal cord injury and in amyotrophic lateral sclerosis

Meaningful body movements depend on the interplay between synaptic inputs to motoneurons and their intrinsic properties. Injury and disease often alter either or both of these factors and cause motoneuron and movement dysfunction. The ability of the motoneuronal membrane to generate persistent inward currents (PICs) is especially potent in setting the intrinsic excitability of motoneurons and can drastically change the motoneuron output to a given input. In this article, we review the role of PICs in modulating the excitability of spinal motoneurons during health, and their contribution to motoneuron excitability after spinal cord injury (SCI) and in amyotrophic lateral sclerosis (ALS) leading to exaggerated long-lasting reflexes and muscle spasms, and contributing to neuronal degeneration, respectively.     

Altered distributions of nucleocytoplasmic transport-related proteins in the spinal cord of a mouse model of amyotrophic lateral sclerosis

Recent investigations have indicated that the nucleocytoplasmic transport system is essential for maintaining cell viability and cellular functions and that its dysfunction could lead to certain disorders. To investigate the involvement of this system in the pathomechanisms of amyotrophic lateral sclerosis (ALS), we examined the immunohistochemical localization of proteins associated with nucleocytoplasmic transport in the lumbar spinal cord in a mutant SOD1 (G93A) transgenic mouse model of ALS. This model is widely used for ALS research, and the mutant mice are known to exhibit neuronal loss and Lewy body-like hyaline inclusions (LBHIs) in the anterior horns, similar to the pathology seen in familial ALS patients associated with an SOD1 mutation and in several other transgenic rodent models. Using antibodies against the importin beta family of proteins, the major carrier proteins of nucleocytoplasmic transport, and those against their adapter protein, importin alpha, we found that the immunoreactivities were decreased within the nuclei and increased within the cytoplasm of a subset of the surviving anterior horn cells of the transgenic mice. In addition, LBHIs were invariably reactive toward these antibodies. Furthermore, the immunoreactivities for histone H1 and beta-catenin, representative cargo proteins transported by importin beta-dependent and beta-independent nucleocytoplasmic transport pathways, respectively, showed distributions similar to those for importin beta family and importin alpha proteins. The altered distributions of these proteins were not associated with caspase-3 expression, suggesting that the findings are unlikely to be a manifestation of apoptotic processes. Chronological quantitative analysis of importin beta-immunostained sections from the transgenic mice revealed a statistically significant progressive decrease in the proportion of the anterior horn cells exhibiting a more intense reactivity for these proteins in the nucleus than in the cytoplasm. To the contrary, we found that the anterior horn cells with the immunoreactivity in their cytoplasm, being more pronounced than that in their nucleus, were significantly increased in number along with the disease progression. This is the first report investigating nucleocytoplasmic transport in the ALS model mouse, and our present results imply that its dysfunction could be involved in the pathomechanisms underlying ALS.     

Phosphorylated Smad2/3 immunoreactivity in sporadic and familial amyotrophic lateral sclerosis and its mouse model

Phosphorylated Smad2/3 (pSmad2/3), the central mediators of transforming growth factor (TGF)-beta signaling, were recently identified in tau-positive inclusions in certain neurodegenerative disorders. To clarify whether the localization of pSmad2/3 is altered in amyotrophic lateral sclerosis (ALS), we immunohistochemically examined spinal cords from sporadic ALS (SALS), from familial ALS (FALS) patients with the A4V mutation in their Cu/Zn superoxide dismutase (SOD1) gene, and from G93A mutant SOD1 transgenic (mSOD1 Tg) mice. In control spinal cords, pSmad2/3 immunoreactivity was observed exclusively in neuronal and glial nuclei. In SALS and FALS patients the nuclei showed increased immunoreactivity for pSmad2/3. Noticeably, round hyaline inclusions (RHIs) and skein-like inclusions of SALS patients were immunoreactive for pSmad2/3. Double immunofluorescence staining for pSmad2/3 and transactive response-DNA-binding protein (TDP)-43 revealed co-localization of these proteins within RHIs. In contrast, Bunina bodies in SALS and Lewy body-like hyaline inclusions (LBHIs) in FALS were devoid of labeling for pSmad2/3. Similarly, in the mSOD1 Tg mice pSmad2/3 immunoreactivity was increased in the nuclei, while LBHIs were not labeled. These findings suggest increased TGF-beta-Smad signaling in SALS, FALS, and mSOD1 Tg mice, as well as impaired TGF-beta signal transduction in RHI-bearing neurons of SALS patients, presumably at the step of pSmad2/3 translocation into the nucleus. The pathomechanisms, including the process of inclusion development, appears to be different between SALS and mSOD1-related FALS or Tg mice.