Development and validation of Spasticity Index-Amyotrophic Lateral Sclerosis.

OBJECTIVES: Spasticity is a common and disabling feature of amyotrophic lateral sclerosis (ALS). There are currently no validated ALS-specific measures of spasticity. The aim of this study was to develop and use a self-report outcome measure for spasticity in ALS. METHODS: Following semi-structured interviews with 11 ALS patients, a draft scale was administered across ALS clinics in the UK. Internal validity of the scale was examined using the Rasch model. The numerical rating scale (NRS) for spasticity and Leeds Spasticity scale (LSS) were co-administered. The final scale was used in a path model of spasticity and quality of life. RESULTS: A total of 465 patients (mean age 64.7 years (SD 10), 59% male) with ALS participated. Spasticity was reported by 80% of subjects. A pool of 71 items representing main themes of physical symptoms, negative impact and modifying factors was subject to an iterative process of item reduction by Rasch analysis resulting in a 20-item scale-the Spasticity Index for ALS (SI-ALS)-which was unidimensional and free from differential item functioning. Moderate correlations were found with LSS and NRS-spasticity. Incorporating the latent estimate of spasticity into a path model, greater spasticity reduced quality of life and motor function; higher motor function was associated with better quality of life. CONCLUSIONS: The SI-ALS is a disease-specific self-report scale, which provides a robust interval-level measure of spasticity in ALS. Spasticity has a substantial impact on quality of life in ALS.

Peripheral myelin protein-22 gene maps in the duplication in chromosome 17p11.2 associated with Charcot-Marie-Tooth 1A.

Charcot-Marie-Tooth disease 1A (CMT1A) is a hereditary demyelinating peripheral neuropathy, associated with a DNA duplication on chromosome 17p11.2. A related disorder in the mouse, trembler (Tr), maps to mouse chromosome 11 which has syntenic homology to human chromosome 17p. Recently, the peripheral myelin protein-22 (pmp-22) gene was identified as the likely Tr locus. We have constructed a partial yeast artificial chromosome contig spanning the CMT1A gene region and mapped the PMP-22 gene to the duplicated region. These observations further implicate PMP-22 as a candidate gene for CMT1A, and suggest that over-expression of this gene may be one mechanism that produces the CMT1A phenotype.

The peripheral myelin protein gene PMP-22 is contained within the Charcot-Marie-Tooth disease type 1A duplication.

Charcot-Marie-Tooth disease (CMT1) is the most common form of inherited peripheral neuropathy. Although the disease is genetically heterogeneous, it has been demonstrated that the gene defect is the most frequent type (CMT1A) is the result of a partial duplication of band 17p11.2. Recent studies suggested that the peripheral hypomyelination syndrome in the trembler (Tr) mouse, a possible animal model for CMT1 disease, is associated with a point mutation in the peripheral myelin protein-22 gene (pmp-22). Expression of pmp-22 is particularly high in Schwann cells, and the protein is found in peripheral myelin. We now report that the human PMP-22 gene is contained within the CMT1A duplication. We therefore, suggest that increased dosage of the PMP-22 gene may be the cause of CMT1A neuropathy.

Δ9-tetrahydrocannabinol (Δ9-THC) exerts a direct neuroprotective effect in a human cell culture model of Parkinson's disease.

AIMS: Δ9-tetrahydrocannabinol (Δ9-THC) is neuroprotective in models of Parkinson's disease (PD). Although CB1 receptors are increased within the basal ganglia of PD patients and animal models, current evidence suggests a role for CB1 receptor-independent mechanisms. Here, we utilized a human neuronal cell culture PD model to further investigate the protective properties of Δ9-THC. METHODS: Differentiated SH-SY5Y neuroblastoma cells were exposed to PD-relevant toxins: 1-methyl-4-phenylpyridinium (MPP+), lactacystin and paraquat. Changes in CB1 receptor level were determined by quantitative polymerase chain reaction and Western blotting. Cannabinoids and modulatory compounds were co-administered with toxins for 48 h and the effects on cell death, viability, apoptosis and oxidative stress assessed. RESULTS: We found CB1 receptor up-regulation in response to MPP+, lactacystin and paraquat and a protective effect of Δ9-THC against all three toxins. This neuroprotective effect was not reproduced by the CB1 receptor agonist WIN55,212-2 or blocked by the CB1 antagonist AM251. Furthermore, the antioxidants α-tocopherol and butylhydroxytoluene as well as the antioxidant cannabinoids, nabilone and cannabidiol were unable to elicit the same neuroprotection as Δ9-THC. However, the peroxisome proliferator-activated receptor-gamma (PPARγ) antagonist T0070907 dose-dependently blocked the neuroprotective, antioxidant and anti-apoptotic effects of Δ9-THC, while the PPARγ agonist pioglitazone resulted in protection from MPP+-induced neurotoxicity. Furthermore, Δ9-THC increased PPARγ expression in MPP+-treated SH-SY5Y cells, another indicator of PPARγ activation. CONCLUSIONS: We have demonstrated up-regulation of the CB1 receptor in direct response to neuronal injury in a human PD cell culture model, and a direct neuronal protective effect of Δ9-THC that may be mediated through PPARγ activation.

Measuring coping in people with amyotrophic lateral sclerosis using the Coping Index-ALS: A patient derived, Rasch compliant scale.

OBJECTIVE: The progressively disabling and terminal nature of ALS/MND imposes major coping demands on patients. We wished to improve the psychometric properties of our previously published MND-Coping Scale, so that parametric analyses were valid, and to make it simpler for patients to complete and clinicians to score. METHODS: After a new qualitative analysis of 26 patients with ALS/MND, the draft Coping Index-ALS (CI-ALS) was administered to 465 additional patients, alongside COPE-60, General Perceived Self Efficacy scale, and WHOQOL-BREF. Validity of the CI-ALS was assessed using the Rasch model. External validity was checked against comparator measures. RESULTS: Thirteen centres contributed 465 patients, mean age 64.9 years (SD 10.8), mean disease duration 28.4 months (SD 37.5). The CI-ALS-Self and CI-ALS-Others both satisfied Rasch model expectations and showed invariance across age, gender, marital status and type of onset. Expected correlations were observed with comparator scales. A nomogram is available to convert the raw scores to interval level measures suitable for parametric analysis. CONCLUSIONS: Coping abilities in ALS/MND can now be measured using a simple 21 item self-report measure, offering two subscales with a focus of 'coping by self ' and 'coping with others'. This allows clinicians to identify individuals with poor coping and facilitates research on interventions that may improve coping skills.

Magic but treatable? Tumours due to loss of merlin.

Alterations in the NF2 gene coding for merlin cause all tumours that occur in patients suffering from neurofibromatosis type 2, all spontaneous schwannomas and the majority of meningiomas. Thus merlin's tumours are quite frequent and also numerous when inherited as part of meurofibromatosis type 2. Tumours caused by mutations in the NF2 gene are benign and thus do not respond to classical chemotherapy. Surgery and radiosurgery are only local therapies and the patients frequently require multiple treatments. This highlights the medical need to understand how merlin loss results in tumourigenesis and the need to find new systemic therapies. The benign, and therefore genetically stable and homogenous character of the tumours allows establishment of meaningful tumour models. This brings about the rather unique opportunity to both analyse the consequences of the gene defect and identify new therapeutic targets. In this review, I will first describe the phenotypes associated with 'merlin' mutations and consider differential diagnosis, in particular Schwannomatosis, for which a gene defect has been described recently. Existing therapeutic options, surgery and radiosurgery, including new data on the latter will be reviewed. Finally, I will discuss how loss of merlin leads to tumourigenesis in order to understand the rationale for emerging new therapeutic targets.

High concentrations of cannabinoids activate apoptosis in human U373MG glioma cells.

Cannabinoids bind to two G-protein-coupled receptors, CB1 and CB2, expressed by neurons and cells of the immune system, respectively. Glioma cells (astrocyte-derived brain tumor cells) express cannabinoid receptors, and numerous in vitro and in vivo studies performed in rodents have concluded that apoptosis could be induced by cannabinoids in these cells. Whether this also applies to human cells is controversial; we, therefore, assessed the effect of cannabinoids on human glioma cell viability with the human astrocytoma cell line U373MG. We report here that U373MG human glioma cells are sensitive only to high concentrations of cannabinoids (>5 microg/ml for Delta(9)-THC). Similar concentrations of the compounds promoted a rapid activation of extracellular-regulated kinase and c-Jun NH2-terminal kinase, suggesting that cannabinoid receptors are functional in U373MG cells. Nevertheless, these kinases are not involved in cannabinoid-induced cell death in U373MG cells, insofar as blocking their activation with specific inhibitors does not reduce cell death. CB1 is expressed in U373MG cells and is involved in cannabinoid-induced cell death, in that blocking its activation with a specific antagonist (AM251) almost totally prevented cell death following incubation of the cells with Delta(9)-THC. In addition, as already reported, some cannabinoids may have modest proproliferative properties in U373MG cells. Human U373MG glioma cells are sensitive only to very high, pharmacologically irrelevant concentrations of cannabinoids, so it seems unlikely that cannabinoids would constitute promising molecules for treating malignant astrocytoma; they do not induce glioma cell death at doses that could be applied safely to humans.

A functional association between merlin and HEI10, a cell cycle regulator.

Merlin and ezrin are homologous proteins with opposite effects on neoplastic growth. Merlin is a tumor suppressor inactivated in the neurofibromatosis 2 disease, whereas upregulated ezrin expression is associated with increased malignancy. Merlin's tumor suppressor mechanism is not known, although participation in cell cycle regulation has been suggested. To characterize merlin's biological activities, we screened for molecules that would interact with merlin but not ezrin. We identified the cyclin B-binding protein and cell cycle regulator HEI10 as a novel merlin-binding partner. The interaction is mediated by the alpha-helical domain in merlin and the coiled-coil domain in HEI10 and requires conformational opening of merlin. The two proteins show partial subcellular colocalization, which depends on cell cycle stage and cell adhesion. Comparison of Schwann cells and schwannoma cultures demonstrated that the distribution of HEI10 depends on merlin expression. In transfected cells, a constitutively open merlin construct affected HEI10 protein integrity. These results link merlin to the cell cycle control machinery and may help to understand its tumor suppressor function.

Cellular prion protein (PrPC) in the development of Merlin-deficient tumours.

Loss of function mutations in the neurofibromatosis Type 2 (NF2) gene, coding for a tumour suppressor, Merlin, cause multiple tumours of the nervous system such as schwannomas, meningiomas and ependymomas. These tumours may occur sporadically or as part of the hereditary condition neurofibromatosis Type 2 (NF2). Current treatment is confined to (radio) surgery and no targeted drug therapies exist. NF2 mutations and/or Merlin inactivation are also seen in other cancers including some mesothelioma, breast cancer, colorectal carcinoma, melanoma and glioblastoma. To study the relationship between Merlin deficiency and tumourigenesis, we have developed an in vitro model comprising human primary schwannoma cells, the most common Merlin-deficient tumour and the hallmark for NF2. Using this model, we show increased expression of cellular prion protein (PrPC) in schwannoma cells and tissues. In addition, a strong overexpression of PrPC is observed in human Merlin-deficient mesothelioma cell line TRA and in human Merlin-deficient meningiomas. PrPC contributes to increased proliferation, cell-matrix adhesion and survival in schwannoma cells acting via 37/67 kDa non-integrin laminin receptor (LR/37/67 kDa) and downstream ERK1/2, PI3K/AKT and FAK signalling pathways. PrPC protein is also strongly released from schwannoma cells via exosomes and as a free peptide suggesting that it may act in an autocrine and/or paracrine manner. We suggest that PrPC and its interactor, LR/37/67 kDa, could be potential therapeutic targets for schwannomas and other Merlin-deficient tumours.

Pathogenesis of Charcot-Marie-Tooth 1A (CMT1A) neuropathy.

The hereditary neuropathy Charcot-Marie-Tooth (CMT) type 1A is, in the majority of cases, caused by duplication of the gene for the peripheral myelin protein PMP22, which leads to abnormally increased PMP22 expression. Recent in vitro and in vivo data indicate a novel function of PMP22 in Schwann-cell growth and differentiation other than its role in myelination, and suggest that overproduction of PMP22 leads to a new Schwann-cell phenotype in CMT1A. Taking these data into account, we developed a new hypothesis on the pathogenesis of CMT1A neuropathy: that the defective myelin stability and turnover observed in the disease is caused by altered PMP22 gene dosage and its resultant effect on abnormal Schwann-cell growth and differentiation.

News on the genetics, epidemiology, medical care and translational research of Schwannomas.

Recent years have seen substantial news and updates in the genetics and diagnosis of schwannomas, even a new hereditary disease with schwannomas; Schwannomatosis has been defined. These developments have consequently led to better evaluation of the incidence of schwannomas. Although there has also been progress in the treatment of schwannomas especially in the field of radiation therapy, hereditary diseases with multiple tumours still represent a therapeutic dilemma. NF2 in particular still causes major morbidity and mortality owing to the neurological deficit of multiple tumour disease and deafness caused by vestibular nerve involvement. Thus there has been great enthusiasm about disease models in the hope that translational research will give rise to new therapies.

Benign symmetric lipomatosis with axonal neuropathy and abnormalities in specific mitochondrial tRNA regions.

Benign symmetric lipomatosis, also called Madelung's disease, is characterized by lipomata and fatty infiltrations. Involvement of the nervous system has occasionally been described, mitochondrial dysfunctions have been suggested. We report a 55 year old male suffering from benign symmetric lipomatosis with associated axonal neuropathy and hyperlipoproteinemia. He showed a remarkable phenotype of neuropathy i.e. no sensory disturbance, ubiquitous fasciculations and muscle cramps, furthermore reduced COX activity and abnormalities in specific mitochondrial tRNA regions.

The scaffold protein KSR1, a novel therapeutic target for the treatment of Merlin-deficient tumors.

Merlin has broad tumor-suppressor functions as its mutations have been identified in multiple benign tumors and malignant cancers. In all schwannomas, the majority of meningiomas and 1/3 of ependymomas Merlin loss is causative. In neurofibromatosis type 2, a dominantly inherited tumor disease because of the loss of Merlin, patients suffer from multiple nervous system tumors and die on average around age 40. Chemotherapy is not effective and tumor localization and multiplicity make surgery and radiosurgery challenging and morbidity is often considerable. Thus, a new therapeutic approach is needed for these tumors. Using a primary human in vitro model for Merlin-deficient tumors, we report that the Ras/Raf/mitogen-activated protein, extracellular signal-regulated kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) scaffold, kinase suppressor of Ras 1 (KSR1), has a vital role in promoting schwannomas development. We show that KSR1 overexpression is involved in many pathological phenotypes caused by Merlin loss, namely multipolar morphology, enhanced cell-matrix adhesion, focal adhesion and, most importantly, increased proliferation and survival. Our data demonstrate that KSR1 has a wider role than MEK1/2 in the development of schwannomas because adhesion is more dependent on KSR1 than MEK1/2. Immunoprecipitation analysis reveals that KSR1 is a novel binding partner of Merlin, which suppresses KSR1's function by inhibiting the binding between KSR1 and c-Raf. Our proteomic analysis also demonstrates that KSR1 interacts with several Merlin downstream effectors, including E3 ubiquitin ligase CRL4(DCAF1). Further functional studies suggests that KSR1 and DCAF1 may co-operate to regulate schwannomas formation. Taken together, these findings suggest that KSR1 serves as a potential therapeutic target for Merlin-deficient tumors.

Axon damage in CMT due to mutation in myelin protein P0.

We describe a family carrying the Thr148Met mutation in the P0 gene. Contrary to other neuropathies caused by myelin gene defects, no demyeliantion could be found in our biopsies. Based on follow up examinations, extensive morphometry and immunohistochemical analysis we suggest that the mild hypomyelination documented in our family secondarily causes axonal degeneration and axonal loss of large and small fibers which predominates the clinical picture.

Expression of decorin mRNA in the nervous system of rat.

A rat cDNA clone (pCD67) isolated from a cDNA library of regenerating sciatic nerve by differential hybridization screening revealed 75% homology on the nucleic acid level and 81% homology (including conservative amino acid changes) to the deduced amino acid sequence of the core protein of human dermatan/chondroitin sulfate proteoglycan decorin (PGII, PG40, PG-S2). Two transcripts of 1.3 and 1.75 KB very similar in size to the two decorin mRNA species previously identified in connective tissue were detected by Northern blotting in both normal and injured sciatic nerve and in the mature and embryonic rat brain. The steady-state level of the decorin 1.3 KB mRNA was very much higher in peripheral nerve than in the central nervous system or in other non-neural tissues (skeletal muscle, heart, colon, kidney). In situ hybridization experiments indicated that decorin mRNA is expressed by Schwann cells and vascular cells in peripheral nerve. In the spinal cord the ventral horn motor neurons and other neurons in gray matter showed specific hybridization signals. Furthermore, in situ hybridization indicated decorin expression in Purkinje neurons and cells of the molecular layer in cerebellum, and in neurons of the primary olfactory cortex and brainstem (pons). Our data clearly demonstrate decorin mRNA expression in distinct neural cell populations, suggesting yet unknown functions of this proteoglycan in the peripheral and central nervous system.

Recurrent hematomas following craniotomy for traumatic intracranial mass.

Of 850 patients who underwent craniotomy for evacuation of a traumatic intracranial mass, 59 (6.9%) developed a second hematoma at the operation site, which required a second operation. Compared to those who did not, patients who developed postcraniotomy hematoma (PCH) had a significantly higher incidence of evidence of alcohol intake and preoperative mannitol administration; a higher percentage had a bad outcome. Coagulopathy was frequent in PCH patients. Although three-quarters of the initial hematomas were intradural, 69% of the PCH's were predominantly extradural. The large potential space underlying a craniotomy bone flap may predispose to development of a PCH. Intracranial pressure (ICP) was monitored in 39 of the 59 PCH patients, which allowed earlier detection of the PCH in 22 (56%). In 17 patients, the ICP failed to rise despite clinical deterioration, and detection of the PCH was delayed, significantly worsening the outcome in this group.

Artesunate induces necrotic cell death in schwannoma cells.

Established as a potent anti-malaria medicine, artemisinin-based drugs have been suggested to have anti-tumour activity in some cancers. Although the mechanism is poorly understood, it has been suggested that artemisinin induces apoptotic cell death. Here, we show that the artemisinin analogue artesunate (ART) effectively induces cell death in RT4 schwannoma cells and human primary schwannoma cells. Interestingly, our data indicate for first time that the cell death induced by ART is largely dependent on necroptosis. ART appears to inhibit autophagy, which may also contribute to the cell death. Our data in human schwannoma cells show that ART can be combined with the autophagy inhibitor chloroquine (CQ) to potentiate the cell death. Thus, this study suggests that artemisinin-based drugs may be used in certain tumours where cells are necroptosis competent, and the drugs may act in synergy with apoptosis inducers or autophagy inhibitors to enhance their anti-tumour activity.

Axl/Gas6/NFκB signalling in schwannoma pathological proliferation, adhesion and survival.

TAM family receptor tyrosine kinases comprising Tyro3 (Sky), Axl, and Mer are overexpressed in some cancers, correlate with multidrug resistance and contribute to tumourigenesis by regulating invasion, angiogenesis, cell survival and tumour growth. Mutations in the gene coding for a tumour suppressor merlin cause development of multiple tumours of the nervous system such as schwannomas, meningiomas and ependymomas occurring spontaneously or as part of a hereditary disease neurofibromatosis type 2. The benign character of merlin-deficient tumours makes them less responsive to chemotherapy. We previously showed that, amongst other growth factor receptors, TAM family receptors (Tyro3, Axl and Mer) are significantly overexpressed in schwannoma tissues. As Axl is negatively regulated by merlin and positively regulated by E3 ubiquitin ligase CRL4DCAF1, previously shown to be a key regulator in schwannoma growth we hypothesized that Axl is a good target to study in merlin-deficient tumours. Moreover, Axl positively regulates the oncogene Yes-associated protein, which is known to be under merlin regulation in schwannoma and is involved in increased proliferation of merlin-deficient meningioma and mesothelioma. Here, we demonstrated strong overexpression and activation of Axl receptor as well as its ligand Gas6 in human schwannoma primary cells compared to normal Schwann cells. We show that Gas6 is mitogenic and increases schwannoma cell-matrix adhesion and survival acting via Axl in schwannoma cells. Stimulation of the Gas6/Axl signalling pathway recruits Src, focal adhesion kinase (FAK) and NFκB. We showed that NFκB mediates Gas6/Axl-mediated overexpression of survivin, cyclin D1 and FAK, leading to enhanced survival, cell-matrix adhesion and proliferation of schwannoma. We conclude that Axl/FAK/Src/NFκB pathway is relevant in merlin-deficient tumours and is a potential therapeutic target for schwannoma and other merlin-deficient tumours.