Susanne Petri

EFNS guidelines on the clinical management of Amyotrophic Lateral Sclerosis (MALS) - revised report of an EFNS task force

Background:  The evidence base for the diagnosis and management of amyotrophic lateral sclerosis (ALS) is weak.

Guidelines for preclinical animal research in ALS/MND: A consensus meeting

The development of therapeutics for ALS/MND is largely based on work in experimental animals carrying human SOD mutations. However, translation of apparent therapeutic successes from in vivo to the human disease has proven difficult and a considerable amount of financial resources has been apparently wasted. Standard operating procedures (SOPs) for preclinical animal research in ALS/MND are urgently required. Such SOPs will help to establish SOPs for translational research for other neurological diseases within the next few years. To identify the challenges and to improve the research methodology, the European ALS/MND group held a meeting in 2006 and published guidelines in 2007 (1). A second international conference to improve the guidelines was held in 2009. These second and improved guidelines are dedicated to the memory of Sean F. Scott.

Thalidomide and Lenalidomide Extend Survival in a Transgenic Mouse Model of Amyotrophic Lateral Sclerosis

Accumulating evidence suggests that inflammation plays a major role in the pathogenesis of motor neuron death in amyotrophic lateral sclerosis (ALS). Important mediators of inflammation such as the cytokine tumor necrosis factor-α (TNF-α) and its superfamily member fibroblast-associated cell-surface ligand (FasL) have been implicated in apoptosis. We found increased TNF-α and FasL immunoreactivity in lumbar spinal cord sections of ALS patients and G93A transgenic mice. Both increased TNF-α and FasL immunostaining in the lumbar spinal cord of the G93A SOD1 transgenic mice occurred at 40–60 d, well before the onset of symptoms and loss of motor neurons. We tested the neuroprotective effect of thalidomide and its analog lenalidomide, pharmacological agents that inhibit the expression of TNF-α and other cytokines by destabilizing their mRNA. Treatment with either thalidomide or lenalidomide attenuated weight loss, enhanced motor performance, decreased motor neuron cell death, and significantly increased the life span in G93A transgenic mice. Treated G93A mice showed a reduction in TNF-α and FasL immunoreactivity as well as their mRNA in the lumbar spinal cord. Both compounds also reduced interleukin (IL)-12p40, IL-1α, and IL-1β and increased IL-RA and TGF-β1 mRNA. Therefore, both thalidomide and lenalidomide bear promise as therapeutic interventions for the treatment of ALS.

Deregulation of TDP-43 in amyotrophic lateral sclerosis triggers nuclear factor κB-mediated pathogenic pathways.

TDP-43 interacts with and coactivates NF-κB p65 in the spinal cord of amyotrophic lateral sclerosis (ALS) patients, and an NF-κB inhibitor suppresses ALS disease symptoms and neuromuscular junction denervation in an ALS mouse model.

ALSFRS-R score and its ratio: a useful predictor for ALS-progression.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder. To determine predictors of survival, we studied different parameters in our ALS Database including 479 patients. The effects of individual prognostic factors of survival were studied using Kaplan-Meier life table. The prognostic value of each factor of interest was expressed in terms of a hazard ratio. Survival from symptom-onset ranged from 4 months up to 11.9 years. Gender had no effect on survival in our cohort. However, age, site of onset, forced vital capacity, symptom duration and ALSFRS-R score at the first visit were independent prognostic factors in our population (log-rank p<0.01). The ratio of ALSFRS-R score between first symptom and first examination, during whole disease or within 100 days, correlates with survival time. We conclude that the ratio of ALSFRS-R score within 100 days is a useful parameter for clinical trials and daily clinical work in a tertiary ALS-clinic.

Nuclear Erythroid 2-Related Factor 2-Antioxidative Response Element Signaling Pathway in Motor Cortex and Spinal Cord in Amyotrophic Lateral Sclerosis

Abstract Oxidative stress and inflammation are important pathogenetic mechanisms in amyotrophic lateral sclerosis (ALS). Nuclear erythroid 2-related factor 2 (Nrf2) is a basic region leucine-zipper transcription factor that binds to the antioxidant response element, thereby regulating the expression of many genes that are involved in cellular antioxidant and anti-inflammatory defense. Under normal conditions, Nrf2 activation is inhibited by Kelch-like ECH-associated protein 1 (Keap1). We investigated the potential involvement of the Nrf2/antioxidant response element signaling pathway in the selective degeneration of motor neurons in ALS. Nrf2 and Keap1 expression was analyzed in primary motor cortex and spinal cord postmortem tissue samples from ALS patients and controls by in situ hybridization histochemistry, quantitative real-time polymerase chain reaction, immunohistochemistry, and Western blot analysis. In ALS samples, there was a reduction of Nrf2 mRNA and protein expression in neurons, whereas Keap1 mRNA expression was increased in the motor cortex. These results suggest that alterations in this signaling cascade occur in motor neurons in ALS and that they may contribute to chronic motor neuron degeneration.

Nrf2/ARE Signaling Pathway: Key Mediator in Oxidative Stress and Potential Therapeutic Target in ALS

Nrf2 (nuclear erythroid 2-related factor 2) is a basic region leucine-zipper transcription factor which binds to the antioxidant response element (ARE) and thereby regulates the expression of a large battery of genes involved in the cellular antioxidant and anti-inflammatory defence as well as mitochondrial protection. As oxidative stress, inflammation and mitochondrial dysfunctions have been identified as important pathomechanisms in amyotrophic lateral sclerosis (ALS), this signaling cascade has gained interest both with respect to ALS pathogenesis and therapy. Nrf2 and Keap1 expressions are reduced in motor neurons in postmortem ALS tissue. Nrf2-activating compounds have shown therapeutic efficacy in the ALS mouse model and other neurodegenerative disease models. Alterations in Nrf2 and Keap1 expression and dysregulation of the Nrf2/ARE signalling program could contribute to the chronic motor neuron degeneration in ALS and other neurodegenerative diseases. Therefore, Nrf2 emerges as a key neuroprotective molecule in neurodegenerative diseases. Our recent studies strongly support that the Nrf2/ARE signalling pathway is an important mediator of neuroprotection and therefore represents a promising target for development of novel therapies against ALS, Parkinsons disease (PD), Huntingtons disease (HD), and Alzheimers disease (AD).

Lenalidomide (Revlimid) administration at symptom onset is neuroprotective in a mouse model of amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease which is currently untreatable. Inflammation plays a major role in the pathogenesis of motor neuron death in ALS. Pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) and Fas ligand (FasL) are amongst the most important mediators of neuro-inflammation. We have previously demonstrated that elevation of these pro-inflammatory cytokines occurs in both ALS transgenic mice and in human ALS postmortem spinal cord tissues. Lenalidomide is a potent immunomodulatory agent, with the ability to down-regulate pro-inflammatory cytokines and up-regulate anti-inflammatory cytokines. We previously reported the neuroprotective effects of lenalidomide, when treatment was started 2 months prior to onset of disease in the G93A SOD1 transgenic mouse model of ALS. Since in ALS patients, treatment can only begin after the appearance of symptoms, we sought to determine the efficacy of lenalidomide administration starting at symptom onset in the G93A SOD1 mice. We found that lenalidomide treatment extended the survival interval from the age of onset by 18.3 days ( approximately 45%). Additionally, lenalidomide treatment improved rotarod performance, reduced weight loss, and attenuated neuronal cell death in the lumbar spinal cord. Qualitative histological analysis showed that lenalidomide treatment modestly reduced the expression of the proinflammatory cytokines Fas Ligand, IL-1beta, TNF-alpha and CD40 ligand. RNA protection Assay (RPA) on a pre-selected panel of cytokines showed that proinflammatory cytokines were reduced and anti-inflammatory cytokines were up-regulated. These data encourage further clinical evaluation of lenalidomide as therapeutic strategy to block or slow disease progression in human ALS patients.

Significance of behavioural tests in a transgenic mouse model of amyotrophic lateral sclerosis (ALS).

Amyotrophic Lateral Sclerosis (ALS) is a devastating adult-onset motor neuron disorder with marginal therapeutic options. The disease is characterized by progressive degeneration of motor neurons in spinal cord and motor cortex. Transgenic mice carrying the G93A mutation of the superoxide dismutase 1 (SOD1) gene develop a neurodegenerative disease closely mimicking human ALS. Several methods are currently used to record disease onset and progression of the animals in preclinical studies. For the interpretation of these preclinical trials, it is important to assess neurological function as sensitively as possible. In the present study, five different parameters (rotarod performance, weight, footprint analysis for both step length and runtime and the general condition of the mice scored from 1 to 5) were compared with respect to their significance to detect symptom onset and to monitor disease progression in transgenic G93A ALS mice. The rotarod and footprint analyses were performed weekly while the weight was recorded up to three times a week at later time points. General condition was assessed daily. First deficits were detected by rotarod testing and step length analyses. General condition score and weight showed first changes two weeks later. For preclinical testing of novel drug treatments rotarod and footprint analysis for step length therefore seem to be the most effective methods to detect symptom onset and potential treatment induced improvements.

Onset and spreading patterns of upper and lower motor neuron symptoms in amyotrophic lateral sclerosis.

The potential linkage between upper (UMN) and lower motor neuron (LMN) involvement in amyotrophic lateral sclerosis (ALS) has not yet been fully elucidated. There is ongoing discussion as to whether ALS is primarily a disease of UMNs or LMNs.