Muscular mitochondrial function in amyotrophic lateral sclerosis is progressively altered as the disease develops: a temporal study in man

We performed repeated analysis of mitochondrial respiratory function in skeletal muscle (SM) of patients with early-stage sporadic amyotrophic lateral sclerosis (SALS) to determine whether mitochondrial function was altered as the disease advanced. SM biopsies were obtained from 7 patients with newly diagnosed SALS, the same 7 patients 3 months later, and 7 sedentary controls. Muscle fibers were permeabilized with saponin, then skinned and placed in an oxygraphic chamber to measure basal and maximal adenosine diphosphate (ADP)-stimulated respiration rates and to assess mitochondrial regulation by ADP. We found that the maximal oxidative phosphorylation capacity of muscular mitochondria significantly increased, and muscular mitochondrial respiratory complex IV activity significantly decreased as the disease advanced. This temporal study demonstrates for the first time that mitochondrial function in SM in human SALS is progressively altered as the disease develops.     

Alteration in surface muscle electrical anisotropy in the rat SOD1 model of amyotrophic lateral sclerosis

Objective

To evaluate the effects of progressive neurogenic change on surface-measured anisotropy via study in the rat superoxide dismutase 1 (SOD1) G93A amyotrophic lateral sclerosis (ALS) model.

Methods

Eight male ALS rats were studied over a period of 10 weeks. In each, the 20 kHz to 1 MHz electrical impedance of the gastrocnemius-soleus complex was measured with electrodes placed at 0° and at 90° relative to the major muscle fiber direction. The major outcome measure, the anisotropy difference (AD) for each of the resistance, reactance, and phase, was calculated as 90-0° values.

Results

All three parameters showed substantial alterations with disease progression. However, the phase AD demonstrated the most substantial change, increasing from 1.8 ± 1.58° to 10.2 ± 2.13° (mean ± standard error) comparing the first and last set of measurements (p = 0.028).

Conclusions

Anisotropy increases substantially with disease progression in the ALS rat.

Significance

Measurement of surface electrical anisotropy offers a non-invasive means for quantifying neurogenic change in muscle.     

Effect of nitric oxide on lymphocytes from sporadic amyotrophic lateral sclerosis patients: toxic or protective role?

Abstract Markers of oxidative and nitrosative stress have been found in spinal cord, cortex, cerebrospinal fluid and plasma of patients affected by amyotrophic lateral sclerosis (ALS), a fatal disorder characterised by progressive motor neuron degeneration. In this study, we investigated the effect of the NO-releasing agent, diethylamine NONOate (NONO), on lymphocytes from patients affected by the sporadic form of ALS (SALS) and controls by flow cytometry. In the same experimental conditions we investigated the expression of the antioxidant proteins, Bcl-2 and SOD1. Incubation with NONO induced cell damage in control lymphocytes but did not further damage the already affected untreated SALS lymphocytes. The incubation with NONO induced a time-dependent decrease of Bcl-2 and SOD1 in control lymphocytes. Surprisingly, in SALS lymphocytes the NONO treatment increased the expression of these proteins, which in basal conditions was depressed compared to control lymphocytes.     

Respiratory function in amyotrophic lateral sclerosis

Abstract. The aim of this study was to examine the vital capacity (FVC) and forced expiratory volume in 1 s (FEV 1) in relation to the site of amyotrophic lateral sclerosis (ALS) onset and the duration of the disease. Respiratory involvement is the principal cause of death in ALS patients. The study was conducted at the Department of Neurology, University School of Medicine in Lublin. The study comprised 18 ALS patients. The average duration of ALS was 12 months. The patients were divided into two groups according to the site of ALS onset and into two groups according to the duration of the disease. FVC was significantly higher in the group of patients with a limb onset than in the group of patients with a bulbar onset of the disease. The study has shown respiratory function disturbances in ALS patients. FVC significantly depends on the site of ALS onset but not on the duration of the disease.     

Serum bilirubin concentration in patients with amyotrophic lateral sclerosis

Oxidative stress plays probably an important role in the etiopathogenesis of amyotrophic lateral sclerosis (ALS). It is known that bilirubin (BR) is an endogenous antioxidant. The aim of this study was to evaluate serum BR concentration in ALS patients. BR was determined by automated analyzer in the serum from 30 ALS and 26 healthy control group people. The study showed that serum BR concentration is significantly decreased in ALS patients with a long duration of ALS compared with patients with a short duration (P<0.05), and it is also significantly decreased in ALS patients with a moderate clinical state compared with control group patients (P<0.05). There was no significant difference in BR concentration between the groups of patients classified according to their age and sex, the clinical state, and the type of ALS onset (P>0.05). Results suggest a possibility of endogenous antioxidant system dysfunction in later phase of ALS. A decrease in BR concentration might diminish its protective effect against oxidative injury and could accelerate motor neuron degeneration.     

The physician-patient relationship in amyotrophic lateral sclerosis

The principal models of the physician-patient relationship are analysed in terms of their historical development. An outline is given of the clinical, psychological and ethical particularities of the approach to patients with amyotrophic lateral sclerosis. The peculiarities of this disease are so exclusive that they do not resemble other progressive diseases with a negative prognosis, and therefore require an equally exclusive approach to the physician-patient relationship. This approach should not only be informative, scientific and interpretative-deliberative, but most simultaneously be founded on a solid therapeutic alliance aimed at seeking the best interests of the patients while respecting their autonomy as well as their “good” (not only in the sense of physical well-being, but also in terms of respect for their personal values). This is the only way to confront the conflicts that inevitably arise (especially in advanced stages of the disease) without the risks associated with a desire to escape or to adopt extreme solutions (such as euthanasia and therapeutic insistence) and without the risk of burn-out. Received: 5 May 2000 / Accepted in revised form: 6 December 2000     

Calcium dysregulation, mitochondrial pathology and protein aggregation in a culture model of amyotrophic lateral sclerosis: mechanistic relationship and differential sensitivity to intervention

The combination of Ca(2+) influx during neurotransmission and low cytosolic Ca(2+) buffering contributes to the preferential vulnerability of motor neurons in amyotrophic lateral sclerosis (ALS). This study investigated the relationship among Ca(2+) accumulation in intracellular compartments, mitochondrial abnormalities, and protein aggregation in a model of familial ALS (fALS1). Human SOD1, wild type (SOD1(WT)) or with the ALS-causing mutation G93A (SOD1(G93A)), was expressed in motor neurons of dissociated murine spinal cord-dorsal root ganglia (DRG) cultures. Elevation of mitochondrial Ca(2+) ([Ca(2+)](m)), decreased mitochondrial membrane potential (Δψ) and rounding of mitochondria occurred early, followed by increased endoplasmic reticular Ca(2+) ([Ca(2+)](ER)), elevated cytosolic Ca(2+) ([Ca(2+)](c)), and subsequent appearance of SOD1(G93A) inclusions (a consequence of protein aggregation). [Ca(2+)](c) was elevated to a greater extent in neurons with inclusions than in those with diffusely distributed SOD1(G93A) and promoted aggregation of mutant protein, not vice versa: both [Ca(2+)](c) and the percentage of neurons with SOD1(G93A) inclusions were reduced by co-expressing the cytosolic Ca(2+)-buffering protein, calbindin D-28K; treatment with the heat shock protein inducer, geldanamycin, prevented inclusions but not the increase in [Ca(2+)](c), [Ca(2+)](m) or loss of Δψ, and inhibiting proteasome activity with epoxomicin, known to promote aggregation of disease-causing mutant proteins including SOD1(G93A), had no effect on Ca(2+) levels. Both expression of SOD1(G93A) and epoxomicin-induced inhibition of proteasome activity caused mitochondrial rounding, independent of Ca(2+) dysregulation and reduced Δψ. That geldanamycin prevented inclusions and mitochondrial rounding, but not Ca(2+) dysregulation or loss of Δψ indicates that chaperone-based therapies to prevent protein aggregation may require co-therapy to address these other underlying mechanisms of toxicity.     

Chronological changes of sympathetic outflow to muscles in amyotrophic lateral sclerosis

To confirm correlations between muscle sympathetic nerve activity (MSNA) and patients' chronological data, we selected 40 consecutive patients with sporadic amyotrophic lateral sclerosis (ALS) recorded by similar methods. MSNA at rest was quantified as the number of sympathetic bursts per 100 heartbeats and as the value expressed as a percentage of the predicted value based on control data. Twelve patients who underwent recordings of MSNA twice at intervals of 6 months or more showed marked decreases in MSNA amplitudes and frequencies between examinations. There was a slightly positive correlation between the frequency of MSNA and age, though younger patients exhibited higher values of MSNA than older patients. The standardized value of MSNA correlated negatively with disease duration and disability levels (p<0.01, 0.05, respectively), but several patients with duration shorter than 12 months showed low values of MSNA. Twelve patients who underwent repeated recordings of MSNA showed a significant decrease in the mean standardized value of MSNA (102.6+/-24.9%) at the second examination, compared to the value (114.3+/-18.9%) at the first one. In ALS, sympathetic outflow to muscles tends to increase initially and then decrease with increasing age and duration. This pattern may be similar to chronological changes at motor neurons.     

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。     

Creatine kinase activity in amyotrophic lateral sclerosis patients

Abstract. The aim of this study was to investigate creatine kinase (CK) in the serum of amyotrophic lateral sclerosis (ALS) patients. Previous investigations have shown an increased CK activity in ALS patients and this has been suggested to be an indicator of patients survival. The study was conducted at the Department of Neurology, University School of Medicine in Lublin. Thirty ALS patients took part in the study. The average duration of the disease was 17 months. Serum CK levels were measured by the enzymatic method with N-acethylcysteine. CK was elevated in 43.3% of the ALS patients. There were no significant differences in the serum CK level between the groups of the ALS patients depending on age, sex, duration of the disease, or clinical condition of patients. The CK level was significantly higher in the serum of the patients with a limb onset than in patients with a bulbar onset of ALS. Our study confirmed the increase in the serum CK activity in ALS patients. CK activity depends on a limb onset or a bulbar onset of ALS, but not on the duration of the disease and the severity of the clinical condition.     

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.     

Novel drug development for amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) has become an increasingly attractive area for the pharmaceutical industry, the most experimentally tractable of the neurodegenerative diseases. Mechanisms underlying cell death in ALS are likely to be important in more common but more complex disorders. Riluzole, the only drug launched for treatment ALS is currently undergoing industrial trials for Alzheimer’s, Parkinson’s, Huntington disease, stroke and head injury. Other compounds in Phase III testing for ALS (mecamserin, xaliproden, gabapentin) are also in trials for other neurodegenerative disorders. Mechanisms of action of these advanced compounds are limited to glutamate antagonism, direct or indirect growth factor activity, as well as GABA agonism and interaction with calcium channels. A broader range of mechanisms is represented by compounds in Phase I trials: glutamate antagonism (dextramethorphan/p450 inhibitor; talampanel), growth factors (leukemia inhibiting factor; IL-1 receptor; encapsulated cells secreting CNTF) and antioxidants (TR500, a glutathione-repleting agent; recombinant superoxide dismutase; procysteine.) An even broader range of mechanisms is being explored in preclinical discovery programs. Recognition of the difficulties associated with delivery of protein therapeutics to the CNS has led to development of small molecules interacting either with neurotrophin receptors or with downstream intracellular signalling pathways. Other novel drug targets include caspaces, protein kinases and other molecules influencing apoptosis. High-throughput screens of large libraries of small molecules yield lead compounds that are subsequently optimized by chemists, screened for toxicity, and validated before a candidate is selected for clinical trials. The net is cast wide in early discovery efforts, only about 1% of which result in useful drugs at the end of a decade-long process. Successful discovery and development of novel drugs will increasingly depend on collaborative efforts between the academy and industry.     

Mitochondrial dysfunction due to mutant copper/zinc superoxide dismutase associated with amyotrophic lateral sclerosis is reversed by N-acetylcysteine

We report that the expression of mutant G93A copper/zinc superoxide dismutase (SOD1), associated with familial amyotrophic lateral sclerosis, specifically causes a decrease in MTT reduction rate and ATP levels and an increase in both cytosolic and mitochondrial reactive oxygen species (ROS) production in human neuroblastoma SH-SY5Y cells compared to cells overexpressing wild-type SOD1 and untransfected cells. Exposure to N-acetylcysteine lowers ROS production and returns mitochondrial functional assays to control levels. No large aggregates of human SOD1 are detectable under basal growth conditions in any of the investigated cell lines. After proteasome activity inhibition, SOD1 aggregates can be detected exclusively in G93A-SOD1 cells, even though they do not per se enhance cell death compared to control cell lines. Our findings indicate that mitochondrial homeostasis is affected by mutant SOD1-generated ROS independently from the formation of aggregates and that this alteration is reversed by antioxidants.     

肌萎缩侧索硬化的病毒病因学研究进展

运动神经元病(motor neuron disease,MND)是一组由于上、下运动神经元丢失导致延髓部、四肢、胸部肌肉逐渐无力和萎缩的进展性神经系统退行性疾病.MND多于45～60岁发病,发病率为1～2/100 000,患病率为4～6/100 000,生存期为1～5年~([1]).     

肌萎缩侧索硬化症临床诊断进展

肌萎缩侧索硬化症为致命性神经系统变性疾病,主要累及锥体束、脑干和脊髓前角细胞,临床表现呈进行性加重的肌肉萎缩、无力及痉挛,以及认知损害等,与额颞叶痴呆的临床表现存在部分重叠。约有5%的患者为家族遗传性,临床表现与散发型相似。诊断主要基于患者临床表现、世界神经病学联盟公布的共识,同时排除临床表现相似的疾病。基因检测为加速诊断进程、早期干预提供了新的途径,部分基因突变与特异性表型相关,可据此进行预后评价和遗传学咨询。     

Insulin resistance in amyotrophic lateral sclerosis

Over the last 30 years glucose intolerance has been reported in a significant percentage of patients with amyotrophic lateral sclerosis (ALS). Currently, a controversy exists in determining whether the carbohydrate abnormality is disease-specific or secondary to decreased glucose utilization due to muscle atrophy. A reduction in glucose receptor space had been postulated for a number of neuromuscular diseases including ALS. In order to clarify this issue we have estimated in vivo insulin sensitivity, using the euglycemic insulin clamp technique, in ALS patients and two control groups, matched according to percent ideal weight. The results showed that the glucose infusion rate, an estimate of in vivo insulin sensitivity, ws significantly diminished in ALS patients compared to both normal and disease controls. These results demonstrate that the insulin resistance in this disorder cannot be explained by a decrease in glucose-receptor space and suggest a primary carbohydrate aberration in the disease process itself.     

Three cases of amyotrophic lateral sclerosis in a common occupational environment

Summary Three unrelated school teachers taught in the same school classroom for 2–5 years and subsequently developed amyotrophic lateral sclerosis (ALS) over an 18-year period. This clustering was not accompanied by an increased death rate for ALS in the county where the teachers lived and worked. Statistical analysis revealed that ALS as the cause of death for three teachers from the same school would be highly improbable as a random event. These findings suggest that the patient's shared school environment may have been a source of exposure to an agent pathogenetically significant in the development of their disease.     

Cerebrospinal fluid vascular endothelial growth factor in patients with amyotrophic lateral sclerosis

Oxidative stress and glutamate-mediated toxicity may play an important role in the etiopathogenesis of amyotrophic lateral sclerosis (ALS). The vascular endothelial growth factor (VEGF) is a neuroprotective cytokine activated by hypoxia. The aim of this study was to measure VEGF levels in the cerebrospinal fluid (CSF) of ALS patients. The study concerned 30 ALS patients and 30 control subjects. The VEGF was measured by the enzyme-linked immunosorbent assay. The results have shown that CSF VEGF levels are significantly increased in patients with long duration of ALS and in patients with limb-onset of the disease compared with controls (P<0.05). Moreover, the type of ALS patients’ subgroup significantly influences CSF VEGF levels (P=0.05). The CSF VEGF levels were significantly increased in patients with limb-onset compared to patients with bulbar-onset of ALS, and in patients with long duration of ALS compared to patients with its short duration (P<0.05). There was a significant correlation between CSF VEGF levels and duration of ALS (P<0.05). It seems that a significant increase in CSF VEGF levels in patients with limb-onset of ALS and in patients with long duration of the disease may have a protective role against glutamate-mediated toxicity and oxidative damage of motor neurons. However, the conclusions are limited due to relatively small subgroups of ALS patients and by lack of a control group consisting of healthy persons. Further investigations could help to confirm the results from this preliminary report.     

Ceftriaxone in amyotrophic lateral sclerosis

One hundred and eight patients with amyotrophic lateral sclerosis (ALS) received ceftriaxone 2 g daily i.v. (62) or i.m. (34) or by both routes (12), for 21-day cycles on an open basis. Baseline MRC and Norris scores were similar to those at the end of the first 21-day cycle of therapy. Seven patients showed remarkable clinical improvement, mostly segmental, which started during the first week of treatment and lasted up to 2 months after its completion. Improvement was also noted in seven out of 21 cases given a subsequent cycle of treatment. Based on these findings, the drug is supposed to act by altering the neurochemical transmission at the neuromuscular junction and/or by facilitating the presynaptic uptake of glutamate at the synaptic junction. This hypothesis positively correlates with the results of in vitro experiments showing that ceftriaxone increases ³H-glutamate uptake in rat spinal cord synaptosomes.     

Luyso-pallido-nigral atrophy and amyotrophic lateral sclerosis

Summary The clinical and pathologic findings in a 34-year-old woman with basal ganglia degeneration and amyotrophic lateral sclerosis are reported. The duration of symptoms was 2 years. A maternal uncle had a parkinsonian syndrome with onset at 45 years of age. Neuropathologic examination revealed extensive neuronal loss and gliosis in the corpus Luysii. Nerve cell loss and gliosis also involved both parts of the globus pallidus, and the substantia nigra. The corticospinal tracts were demyelinated in the spinal cord, and neuronal loss was observed in the anterior horns. Only one similar case of pallido-luyso-nigral atrophy associated with amyotrophic lateral sclerosis has, to our knowledge, been reported previously. Such an association may represent more than a coincidental occurrence.