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Ping K Yip,
Chiara Pizzasegola,
Stacy Gladman,
Maria Luigia Biggio,
Marianna Marino,
Maduka Jayasinghe,
Farhan Ullah,
Simon C Dyall, Andrea Malaspina,
Caterina Bendotti,
Adina Michael-Titus
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ABSTRACT: Amyotrophic lateral sclerosis (ALS) is a progressive fatal neurodegenerative disease characterised by loss of motor neurons that currently has no cure. Omega-3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA), have many health benefits including neuroprotective and myoprotective potential. We tested the hypothesis that a high level of dietary EPA could exert beneficial effects in ALS. The dietary exposure to EPA (300 mg/kg/day) in a well-established mouse model of ALS expressing the G93A superoxide dismutase 1 (SOD1) mutation was initiated at a pre-symptomatic or symptomatic stage, and the disease progression was monitored until the end stage. Daily dietary EPA exposure initiated at the disease onset did not significantly alter disease presentation and progression. In contrast, EPA treatment initiated at the pre-symptomatic stage induced a significantly shorter lifespan. In a separate group of animals sacrificed before the end stage, the tissue analysis showed that the vacuolisation detected in G93A-SOD1 mice was significantly increased by exposure to EPA. Although EPA did not alter motor neurone loss, EPA reversed the significant increase in activated microglia and the astrocytic activation seen in G93A-SOD1 mice. The microglia in the spinal cord of G93A-SOD1 mice treated with EPA showed a significant increase in 4-hydroxy-2-hexenal, a highly toxic aldehydic oxidation product of omega-3 fatty acids. These data show that dietary EPA supplementation in ALS has the potential to worsen the condition and accelerate the disease progression. This suggests that great caution should be exerted when considering dietary omega-3 fatty acid supplements in ALS patients.
PLoS ONE 01/2013; 8(4):e61626. · 4.09 Impact Factor
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ABSTRACT: A mechanical trauma to the spinal cord can be followed by the development of irreversible and progressive neurodegeneration, as opposed to a temporary or partially reversible neurological damage. An increasing body of experimental and clinical evidence from humans and animal models indicates that spinal cord injury may set in motion the development of disabling and at times fatal neuromuscular disorders, whose occurrence is not normally associated with any major environmental event. This outcome appears to be dependent on the co-occurrence of a particular form of mechanical stress and of a genetically-determined vulnerability. This increased vulnerability to spinal cord injury may depend on a change of the nature and of the timing of activation of a number of neuroprotective and neurodestructive molecular signals in the injured cord. Among the main determinants, we could mention an altered homeostasis of lipids and neurofilaments, an earlier inflammatory response and the failure of the damaged tissue to rein in oxidative damage and apoptotic cell death. These changes could force injured tissue beyond a point of no return and precipitate an irreversible neurodegenerative process. A better knowledge of the molecular signals activated in a state of increased vulnerability to trauma can inform future treatment strategies and the prediction of the neurological outcome after spinal cord injury.
Molecular Neurodegeneration 02/2012; 7:6. · 4.28 Impact Factor
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Markus Otto,
Robert Bowser,
Martin Turner,
James Berry,
Johannes Brettschneider,
James Connor,
Júlia Costa,
Merit Cudkowicz,
Jonathan Glass,
Olaf Jahn, [......],
Lucilla Parnetti,
Axel Petzold,
Pamela Shaw,
Alexander Sherman,
Petra Steinacker,
Sigurd Süssmuth,
Charlotte Teunissen,
Hayrettin Tumani,
Anna Wuolikainen,
Albert Ludolph
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ABSTRACT: Despite major advances in deciphering the neuropathological hallmarks of amyotrophic lateral sclerosis (ALS), validated neurochemical biomarkers for monitoring disease activity, earlier diagnosis, defining prognosis and unlocking key pathophysiological pathways are lacking. Although several candidate biomarkers exist, translation into clinical application is hindered by small sample numbers, especially longitudinal, for independent verification. This review considers the potential routes to the discovery of neurochemical markers in ALS, and provides a consensus statement on standard operating procedures that will facilitate multicenter collaboration, validation and ultimately clinical translation.
Amyotrophic Lateral Sclerosis 01/2012; 13(1):1-10. · 3.40 Impact Factor
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ABSTRACT: Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disorder characterised by progressive degeneration of motor neurons leading to death, typically within 3-5 years of symptom onset. The diagnosis of ALS is largely reliant on clinical assessment and electrophysiological findings. Neither specific investigative tools nor reliable biomarkers are currently available to enable an early diagnosis or monitoring of disease progression, hindering the design of treatment trials.
In this study, using the well-established SOD1(G93A) mouse model of ALS and a new in-house ELISA method, we have validated that plasma neurofilament heavy chain protein (NfH) levels correlate with both functional markers of late stage disease progression and treatment response. We detected a significant increase in plasma levels of phosphorylated NfH during disease progression in SOD1(G93A) mice from 105 days onwards. Moreover, increased plasma NfH levels correlated with the decline in muscle force, motor unit survival and, more significantly, with the loss of spinal motor neurons in SOD1 mice during this critical period of decline. Importantly, mice treated with the disease modifying compound arimoclomol had lower plasma NfH levels, suggesting plasma NfH levels could be validated as an outcome measure for treatment trials.
These results show that plasma NfH levels closely reflect later stages of disease progression and therapeutic response in the SOD1(G93A) mouse model of ALS and may potentially be a valuable biomarker of later disease progression in ALS.
PLoS ONE 01/2012; 7(7):e40998. · 4.09 Impact Factor
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ABSTRACT: Neurofilament (Nf) aggregates are a common pathological feature of neurodegenerative disorders. Although Nf levels have been investigated as a potential disease biomarker, Nf aggregates may mask Nf epitopes, preventing accurate quantification by immunoassay. Using the SOD1(G93A) mouse model of amyotrophic lateral sclerosis, we developed a method to disrupt Nf aggregates, allowing optimal immunoassay performance.
Phosphorylated (NfH(SMI35)) and hyperphosphorylated (NfH(SMI34)) Nf levels in plasma from 120-day SOD1(G93A) mice were quantified using an in-house ELISA modified for use with small volumes. Different pre-analytical methods were tested for their ability to solubilize Nf aggregates and immunoblotting was used for qualitative analysis.
A 'hook effect' was observed for serially diluted plasma samples quantified using an ELISA originally developed for CSF samples. Immunoblotting confirmed the existence of high molecular-weight NfH aggregates in plasma and the resolving effect of timed urea on these aggregates. Thermostatic (pre-thawing) and chemical (calcium chelators, urea) pre-analytical processing of samples had variable success in disrupting NfH aggregates. Timed urea-calcium chelator incubation yielded the most consistent plasma NfH levels. A one hour sample pre-incubation with 0.5M urea in Barbitone-EDTA buffer at room temperature resolved the "hook effect" without compromising the ELISA. In SOD1(G93A) mice, median levels of NfH(SMI34) were over 10-fold and NfH(SMI35) levels 5-fold greater than controls.
NfH aggregates can be solubilised and the "hook effect" abolished by a one-hour sample pre-incubation in a urea-calcium chelator-enriched buffer. This method is applicable for quantification of NfH phosphoforms in experimental and disease settings where Nf aggregate formation occurs.
Journal of neuroscience methods 02/2011; 195(2):143-50. · 2.30 Impact Factor
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ABSTRACT: Traumatic injuries can undermine neurological functions and act as risk factors for the development of irreversible and fatal neurodegenerative disorders like amyotrophic lateral sclerosis (ALS). In this study, we have investigated how a mutation of the superoxide dismutase 1 (SOD1) gene, linked to the development of ALS, modifies the acute response to a gentle mechanical compression of the spinal cord. In a 7-day post-injury time period, we have performed a comparative ontological analysis of the gene expression profiles of injured spinal cords obtained from pre-symptomatic rats over-expressing the G93A-SOD1 gene mutation and from wild type (WT) littermates.
The steady post-injury functional recovery observed in WT rats was accompanied by the early activation at the epicenter of injury of several growth-promoting signals and by the down-regulation of intermediate neurofilaments and of genes involved in the regulation of ion currents at the 7 day post-injury time point. The poor functional recovery observed in G93A-SOD1 transgenic animals was accompanied by the induction of fewer pro-survival signals, by an early activation of inflammatory markers, of several pro-apoptotic genes involved in cytochrome-C release and by the persistent up-regulation of the heavy neurofilament subunits and of genes involved in membrane excitability. These molecular changes occurred along with a pronounced atrophy of spinal cord motor neurones in the G93A-SOD1 rats compared to WT littermates after compression injury.
In an experimental paradigm of mild mechanical trauma which causes no major tissue damage, the G93A-SOD1 gene mutation alters the balance between pro-apoptotic and pro-survival molecular signals in the spinal cord tissue from the pre-symptomatic rat, leading to a premature activation of molecular pathways implicated in the natural development of ALS.
BMC Genomics 11/2010; 11:633. · 4.07 Impact Factor
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ABSTRACT: Abstract Background Traumatic injuries can undermine neurological functions and act as risk factors for the development of irreversible and fatal neurodegenerative disorders like amyotrophic lateral sclerosis (ALS). In this study, we have investigated how a mutation of the superoxide dismutase 1 (SOD1) gene, linked to the development of ALS, modifies the acute response to a gentle mechanical compression of the spinal cord. In a 7-day post-injury time period, we have performed a comparative ontological analysis of the gene expression profiles of injured spinal cords obtained from pre-symptomatic rats over-expressing the G93A-SOD1 gene mutation and from wild type (WT) littermates. Results The steady post-injury functional recovery observed in WT rats was accompanied by the early activation at the epicenter of injury of several growth-promoting signals and by the down-regulation of intermediate neurofilaments and of genes involved in the regulation of ion currents at the 7 day post-injury time point. The poor functional recovery observed in G93A-SOD1 transgenic animals was accompanied by the induction of fewer pro-survival signals, by an early activation of inflammatory markers, of several pro-apoptotic genes involved in cytochrome-C release and by the persistent up-regulation of the heavy neurofilament subunits and of genes involved in membrane excitability. These molecular changes occurred along with a pronounced atrophy of spinal cord motor neurones in the G93A-SOD1 rats compared to WT littermates after compression injury. Conclusions In an experimental paradigm of mild mechanical trauma which causes no major tissue damage, the G93A-SOD1 gene mutation alters the balance between pro-apoptotic and pro-survival molecular signals in the spinal cord tissue from the pre-symptomatic rat, leading to a premature activation of molecular pathways implicated in the natural development of ALS.
BMC Genomics. 01/2010;
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ABSTRACT: Mutations of the superoxide dismutase 1 (SOD1) gene are linked to amyotrophic lateral sclerosis (ALS), an invariably fatal neurological condition involving cortico-spinal degeneration. Mechanical injury can also determine spinal cord degeneration and act as a risk factor for the development of ALS.
We have performed a comparative ontological analysis of the gene expression profiles of thoracic cord samples from rats carrying the G93A SOD1 gene mutation and from wild-type littermates subjected to mechanical compression of the spinal cord. Common molecular responses and gene expression changes unique to each experimental paradigm were evaluated against the functional development of each animal model. Gene Ontology categories crucial to protein folding, extracellular matrix and axonal formation underwent early activation in both experimental paradigms, but decreased significantly in the spinal cord from animals recovering from injury after 7 days and from the G93A SOD1 mutant rats at end-stage disease. Functional improvement after compression coincided with a massive up-regulation of growth-promoting gene categories including factors involved in angiogenesis and transcription, overcoming the more transitory surge of pro-apoptotic components and cell-cycle genes. The cord from G93A SOD1 mutants showed persistent over-expression of apoptotic and stress molecules with fewer neurorestorative signals, while functional deterioration was ongoing.
this study illustrates how cytoskeletal protein metabolism is central to trauma and genetically-induced spinal cord degeneration and elucidates the main molecular events accompanying functional recovery or decline in two different animal models of spinal cord degeneration.
BMC Genomics 11/2008; 9:500. · 4.07 Impact Factor
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ABSTRACT: The complex molecular pathways that mediate the effects of vitamin A and its derivatives, are increasingly recognized as a component of the repair capacity that could be activated to induce protection and regeneration in the mature nervous tissue. Retinoid and retinoid-associated signaling plays an essential role in normal neurodevelopment and appears to remain active in the adult CNS. In this paper, we review evidence which supports the hypothesis of an activation of retinoid-associated signaling molecular pathways in the mature nervous tissue and its significance in the context of neurodegenerative, trauma-induced and psychiatric disorders, at spinal and supra-spinal levels. Finally, we summarize the potential therapeutic avenues based on the modulation of retinoid targets undergoing reactivation under conditions of acute injury and chronic degeneration in the central nervous system, and discuss some of the unresolved issues linked to this treatment strategy.
Journal of Neurochemistry 03/2008; 104(3):584-95. · 4.06 Impact Factor
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ABSTRACT: Changes in distribution and expression of retinoid receptors may be part of a spinal cord protective response to acute injury and to chronic degeneration. In this study, we have combined RNA and protein expression analysis to characterize the expression profile of retinoid receptors in the lumbar spinal cord of the superoxide dismutase 1 G93A mutant rat model of amyotrophic lateral sclerosis, a fatal neurodegenerative disorder causing extensive motor neuron loss. We also report a nonsignificant change in RNA expression of binding proteins and metabolizing enzymes for retinol and retinoic acid in the mutant rat spinal cord at end-stage disease. Only retinoid X receptor beta (RXRbeta), and to a lesser extent retinoic acid receptor beta and alpha (RARbeta/alpha) were reliably detected in lumbar spinal cord at an early pre-symptomatic phase and throughout the disease progression. The expression of RXRbeta in lamina II neurons in the dorsal horn of transgenic and wild type (WT) animals was associated with extensive astrocyte staining in end-stage lumbar spinal cord from transgenic rats. RARbeta and RARalpha diffuse staining of large motor neurons in the pre-symptomatic transgenic and in the WT lumbar cord appear to decline in end-stage disease, when a selective and strong gamma motor neuron RARalpha staining becomes evident. As gliosis and motor neuron loss are key pathogenic features in amyotrophic lateral sclerosis, the selective expression of retinoid receptors in astrocytes and motor neurons may provide further clues to the role of retinoid signalling in neurodegeneration and suggest new treatment strategies based on retinoid-modulating agents.
Journal of Neurochemistry 01/2008; 103(5):1821-33. · 4.06 Impact Factor
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ABSTRACT: Spinal cord degenerative pathologies in humans cause extensive disability and require a broad range of specialist and palliative medical interventions. In amyotrophic lateral sclerosis (ALS), motor cell loss leads to extensive paralysis and to death from respiratory failure in 3-5 years form disease onset. A wide range of molecular changes forms the basis of spinal cord involvement in ALS, including the reactivation of molecular pathways with potentially neurorestorative properties. Central to this tissue repair mechanism is the differential regulation of components of the retinoid signaling (ReS), a molecular pathway encompassing a variety of proteins functioning as transporters, signaling factors and metabolizing enzymes for retinoic acid. In this paper, we review the strong body of experimental evidence supporting retinoid signaling's primary role in spinal cord embryonic differentiation and its likely survival-promoting function in ALS. We discuss the potential involvement in ALS pathogenesis of a subgroup of nuclear receptors (NRs) that act as functional partners of retinoid receptors in human spinal cord. We also provide a review of the expression profile of 25 ReS and NRs genes in human adult spinal cord and in motor neurons of healthy and ALS individuals, using data retrieved from independent datasets obtained through serial analysis of gene expression and array investigations. Based on published expression data, we outline a tentative expression profile of ReS and functionally synergic NR genes in human spinal cord that could guide further experiments to clarify the role of these molecules in mature nervous tissue and suggest potential treatment strategies that could have therapeutic potentials in ALS.
Brain Research Bulletin 04/2007; 71(5):437-46. · 2.82 Impact Factor
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ABSTRACT: Flavin-containing monooxygenases (FMO) represent a gene family involved in the oxidative metabolism of a variety of xenobiotics, pesticides and drugs. A new function for FMO proteins has been recently uncovered: yeast FMO has been demonstrated to take part in maintaining the redox balance, catalysing the oxidation of reduced glutathione (GSH) to glutathione disulfide (GSSG). The GSSG/GSH balance is an important buffering system for reactive oxygen species and its involvement has been documented in ALS and other neurodegenerative disorders. Human FMO genes present different mutations, which may be related to ethnicity, altered metabolic activity and, in some cases, specific diseases. The human FMO1 gene presents 20 single nucleotide polymorphisms (SNPs) located in coding regions, intronic sequences and untranslated regions. The FMO1 gene has also recently been found underexpressed in spinal cord of ALS patients. Using SSCP and direct sequencing, we studied the allelic and genotypic frequency of two 3'UTR SNPs of the FMO1 gene in sporadic ALS patients compared to a healthy control population. We found a significantly higher frequency of these two polymorphisms, exclusive of the female population, in SALS patients compared to controls (p<0.01), suggesting that specific allelic variants of the FMO1 gene might be associated to susceptibility to develop ALS.
Amyotrophic lateral sclerosis: official publication of the World Federation of Neurology Research Group on Motor Neuron Diseases 01/2007; 7(4):227-34. · 3.09 Impact Factor
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ABSTRACT: Research efforts in amyotrophic lateral sclerosis (ALS) have not yet provided a comprehensive explanation of the disease pathogenesis, which is emerging as a complex interaction between multiple factors. Gene expression studies traditionally based on single mRNA specie analysis have recently progressed to allow entire transcriptional profiles of affected tissues to be obtained through array-based methods. This experimental approach has significantly improved our understanding of the molecular changes occurring in ALS, although its limitations in the detection of low-abundance transcripts in tissues with a high level of complexity are becoming increasingly recognized. In this paper, experimental findings based on an expression study in post-mortem spinal cord from sporadic ALS individuals will be discussed in light of recently published data using array analysis in an animal model of the disease. Previous expression data obtained using conventional techniques are also compared. Through the analysis of the information arising from ALS post-mortem and animal model tissues studies, we have identified a pattern of molecular events in which factors implicated in the immune response, cytoprotection and growth-differentiation are differentially regulated in a time-dependent way from early to advanced stages of disease progression.
Brain Research Reviews 08/2004; 45(3):213-29. · 10.34 Impact Factor
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ABSTRACT: The "mini-epidemic" distribution of rare conditions (either sporadic, inherited or due to a transmissible agent) is frequently described as a cluster. Genetic abnormalities and environmental factors are usually investigated to explain the presence of a disease cluster. We have reported a cluster of amyotrophic lateral sclerosis (ALS) cases in a small area of central Italy, where an identical SOD1 gene mutation was found both in familial ALS (FALS) cases and in one apparently sporadic ALS individuals. Along with this cluster of ALS patients, we review important clusters of neurological disorders in Italy and discuss the importance of an accurate estimation of their regional/local prevalence. This approach is likely to facilitate molecular investigations, the search for environmental agents and the analysis of gene-environment interaction in disease presentation and development. The organisation of national registers that record, in particular, the geographical distribution of neurological disorders, might represent a good research strategy.
Functional neurology 17(4):177-82. · 1.52 Impact Factor
